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  • Electronic Resource  (232)
  • 1985-1989  (232)
  • 1840-1849
  • 1988  (232)
  • pharmacokinetics  (121)
  • Biochemistry
  • 101
    Electronic Resource
    Electronic Resource
    Plasma drug and antiplatelet profiles of the original acetylsalicylic acid preparations used in the AMIS, PARIS and German-Austrian trials for secondary prevention of myocardial infarction (1988)
    Springer
    European journal of clinical pharmacology 33 (1988), S. 541-547 
    Details
    ISSN: 1432-1041
    Keywords: acetylsalicylic acid ; infarct prevention ; platelet aggregation ; pharmacokinetics ; healthy volunteers ; secondary heart attack prevention ; AMIS ; PARIS ; German-Austrian trials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In a cross-over study 6 healthy male subjects were given for 9 days the acetylsalicylic acid (ASA) preparations used in the Aspirin Myocardial Infarction Study (AMIS), Persantine-Aspirin Reinfarction Study (PARIS) and German-Austrian secondary heart attack prevention trials, exactly according to the original study protocols. Plasma concentrations of ASA and its main metabolites salicylic acid (SA) and salicyluric acid (SUA), as well as platelet function (collagen-induced platelet aggregation; tissue extract-induced change in platelet shape) were studied repeatedly on the first day of each medication period and were again examined on the sixth and ninth days. Differences in the plasma concentrations of ASA and its metabolites were found only on the first day, probably as a result of different absorption rates. Collagen-induced platelet aggregation was more rapidly inhibited the faster the preparation was absorbed. Each ASA preparation inhibited tissue extract-induced platelet shape change from the first dose, although statistically significant inhibition was seen only with the AMIS preparation. It is concluded that differences in the antithrombotic efficiency of ASA cannot be explained by differences in the pharmacokinetic and antiplatelet profiles of the various ASA preparations tested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00542484
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  • 102
    Electronic Resource
    Electronic Resource
    Intrathecal ACNU — a new therapeutic approach against malignant leptomeningeal tumors (1988)
    Springer
    Journal of neuro-oncology 6 (1988), S. 221-226 
    Details
    ISSN: 1573-7373
    Keywords: leptomeningeal tumor ; intrathecal chemotherapy ; ACNU ; nitrosourea ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pharmacokinetics, toxicity and therapeutic efficacy of intrathecal ACNU, 3-((4-amino-2-methyl-5-pyrimidinyl)methyl)-1-(2-chloroethyl)-1-nitrosourea, were studied in rats to determine if it is a new and effective method for the treatment of malignant leptomeningeal tumors. Pharmacokinetics of intracisternally administered ACNU was studied by macroscopial autoradiography using 14C-labeled ACNU. It was demonstrated that intracisternally administered ACNU distributed in the subarachnoid space and subpial layer of the brain in high concentration and was rapidly eliminated into the systemic circulation. The diffusional transport of ACNU into the deeper part of the brain was limited. More than 3.0 mg/kg of intracisternal ACNU induced progressive loss of the weight of body in normal rats, and 80% of the rat given 6.0 mg/kg died. Increase of capillary permeability, neuronal loss and gliosis were observed in the marginal layer of the brain facing to the subarachnoid space in the rat given more than 3.0 mg/kg of ACNU. Systemic and local toxicity was not observed in the rat given less than 1.5 mg/kg. Therapeutic effect of intrathecal ACNU against leptomeningeal tumors was evaluated in the rat with meningeal carcinomatosis induced by intracisternal inoculation of Walker 256 carcinosarcoma cells. The median survival time of the rat treated with 1.5 mg/kg of intracisternal ACNU once on day 2 or on day 5 after tumor inoculation was significantly prolonged by 173%, and 214% at maximum, respectively, as compared with that of the untreated animal. These findings suggest that intrathecal ACNU may be of value for clinical trial against leptomeningeal tumors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00163704
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  • 103
    Electronic Resource
    Electronic Resource
    The use of mass balance principles to describe regional drug distribution and elimination (1988)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 16 (1988), S. 13-29 
    Details
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; mass balance ; regional distribution ; regional elimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Mass balance principles were used to derive a number of terms that are helpful in describing the rate and extent of regional drug uptake. Regional drug uptake was defined as the net movement of drug from the blood perfusing a region into the extravascular space of the region due to the distribution and/or elimination of the drug. By analogy with the traditional physiological definition of flux, net drug flux was defined as the difference in mass per unit time of drug respectively entering and leaving a region via the arterial and venous blood vessels. The timeintegral of net drug flux, net drug mass, was defined as the mass of drug that has entered a region via the arterial blood vessels but has not left the region via the venous blood vessels. For regions in which no drug elimination occurs, the mean regional drug concentration was defined as the net drug mass divided by the mass of the region. When a number of criteria are satisfied, the net drug flux is approximately the rate of drug uptake and the net drug mass is approximately the extent of drug uptake. Several examples are given to demonstrate the broad range of applications of mass balance principles. First, the method was used to characterize the differences between drug distribution and elimination in a hypothetical region using drug concentrations simulated from compartmental models of either distribution alone or distribution with elimination. Second, the whole body distribution net flux was described during a constant rate infusion of iodohippurate (IOH) into a sheep from the difference between the whole body net flux and renal net flux of IOH. Third, the time course of the mean myocardial lignocaine (lidocaine) concentrations in a sheep after an intravenous bolus of lignocaine were described. The time course of the lignocaine-induced depression of myocardial contractility followed more closely the mean myocardial lignocaine concentrations than that of either the arterial or coronary sinus blood concentrations. It is concluded that the use of mass balance principles provides a simple, empirical, and physiologically based method for the determination of the rate and extent of both drug distribution and elimination in regions as simple as single organs or as complex as the whole body.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01061860
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  • 104
    Electronic Resource
    Electronic Resource
    The uptake and elution of lignocaine and procainamide in the hindquarters of the sheep described using mass balance principles (1988)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 16 (1988), S. 31-40 
    Details
    ISSN: 1573-8744
    Keywords: lignocaine ; procainamide ; pharmacokinetics ; mass balance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Mass balance principles were used to describe the uptake and elution of lignocaine (lidocaine) and procainamide in the hindquarters of the sheep. Each of four sheep received a right atrial infusion of either lignocaine · HCl (2.7 mg/min) or procainamide · HCl (5.5mg/min) for 180 min. Paired arterial and inferior vena cava (draining the hindquarters) blood samples were taken at 20-min intervals during the infusion and for 180 min after the infusion. Lignocaine and procainamide mean total body clearances were 2.9 L/min (SD 1.1) and 1.3 L/min (SD 0.2), respectively. An index of the uptake and elution of these drugs in the hindquarters was estimated from the net drug mass per unit hindquarter blood flow;indirect evidence suggested that hindquarter blood flow was constant. All the net mass/flow of procainamide that was taken into the hindquarters during the infusion also eluted after the infusion, demonstrating reversible distribution into the tissues. However, uptake of procainamide was still occurring when blood concentrations were constant, indicating that the concentrations of procainamide in the hindquarters were not in equilibrium with the inferior vena cava concentrations. Lignocaine did not reach constant blood concentrations during the infusion and showed no tendency to reach arteriovenous equilibration; an arteriovenous difference of 22%(SD5%) across the hindquarters was measured during the last 60 min of the infusion. By 180 min after the lignocaine infusions, 79% (SD 8%) of the lignocaine net mass/flow had not eluted from the hindquarters when arterial and venous lignocaine concentrations were not significantly different. This drug could remain uneluted due to metabolism and/or avid tissue binding, and presents difficulties in the interpretation of pharmacokinetic data whether based on arterial or venous blood sampling.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01061861
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  • 105
    Electronic Resource
    Electronic Resource
    On the dose dependency of Cyclosporin a absorption and disposition in healthy volunteers (1988)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 16 (1988), S. 331-353 
    Details
    ISSN: 1573-8744
    Keywords: Cyclosporin A ; pharmacokinetics ; dose dependency ; oral absorption ; disposition ; healthy subjects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics of Cyclosporin A (CyA, SandimmuneR) was studied in 12 healthy male volunteers after oral dosing of 350 mg, 700 mg, and 1400 mg as a drinking solution. Blood samples were collected over 96 hr and analyzed by high pressure liquid chromatography. Concentration data were evaluated with model-independent and model-based linear pharmacokinetic concepts. Individual CyA concentration-time profiles in whole blood were well described by a two-compartment open model with zero-order absorption for all three doses. Comparison of pharmacokinetic parameters across doses indicates that both absorption and disposition are dose-dependent. Nonlinear disposition is suggested by the significant increase of the terminal half-life from 8.9±4.9hr to 11.9±4.9hr (mean±SD) after a 350 mg and a 1400 mg dose, respectively. Changes in the metabolic activity of the liver with concentration might be responsible for this phenomenon. In addition, the modeling approach indicated that bioavailability decreases with increasing dose. Moreover, the dependence of the rate of CyA absorption (zero-order rate constant) versus dose was well described by a hyperbola. The limited solubility of the drug in the gastrointestinal tract might be responsible for this behavior. The lag time (0.2–0.8 hr) was independent of dose. This value is similar to the time of gastric emptying in fasting volunteers. The duration of absorption for 11 of 12 subjects was in the range 2.5–3.5 hr over all doses and agrees well with the small intestine transit time. Some subjects showed a marked secondary peak at one or two doses, which could be adequately fitted by a model with two successive zero-order inputs. This double-peak behavior was ascribed to the influence of the food on gastric emptying. Dose dependency of disposition and absorption counterbalance each other in the usual dose range. This leads to an almost proportional increase of area under the blood CyA concentration-time profile with increasing dose.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01062550
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  • 106
    Electronic Resource
    Electronic Resource
    Pharmacokinetic modeling of the anticonvulsant response of oxazepam in rats using the pentylenetetrazol threshold concentration as pharmacodynamic measure (1988)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 16 (1988), S. 203-228 
    Details
    ISSN: 1573-8744
    Keywords: oxazepam ; pharmacokinetics ; pharmacodynamics ; anticonvulsant response ; pentylenetetrazol threshold ; kinetic-dynamic model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This investigation developed strategies along which the anticonvulsant effect of oxazepam in the rat could be pharmacokinetically modeled. After determination of the pharmacokinetics of oxazepam, which could be described with a two-compartment model (halflives of distribution and elimination 6 and 52 min, respectively), the drug was administered iv to groups of animals to achieve a serum concentration range of 0.1–2.5 mg/L at 10, 45, and 120 min after administration. At these time points pentylenetetrazol (PTZ) was infused slowly until the first myoclonic jerk occurred. The anticonvulsant response, expressed as the elevation of the serum or brain threshold concentration of PTZ, was modeled versus the serum (both total and free) and brain oxazepam concentration, according to the sigmoid E max model. The total serum and brain oxazepam EC50 values are about 0.5 mg/L and 1.1 mg/kg, respectively, and E max 120 mg/L PTZ. No marked differences in pharmacodynamic parameters between the three time groups were found, which indicates that serum and brain are pharmacokinetically indistinguishable from the effect compartment, that there is no (inter) activity of oxazepam metabolites and absence of development of acute tolerance during the investigated time frame. An interfering role of metabolites was also excluded by a direct radioreceptor assay of oxazepam, yielding very similar results as the specific Chromatographic assay. It is concluded that the concentration-anticonvulsant effect relationship of oxazepam can satisfactorily be described by the sigmoid E max model, when utilizing the employed experimental strategies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01062261
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  • 107
    Electronic Resource
    Electronic Resource
    An Implantable Pump for Intrarenal Infusion of Immunosuppressants in a Canine Autotransplant Model (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 781-785 
    Details
    ISSN: 1573-904X
    Keywords: pharmacokinetics ; 6-mercaptopurine ; targeted drug delivery ; renal transplantation ; intraarterial infusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract We developed a canine renal allograft model utilizing implantable infusion pumps and biocompatible catheters to investigate the pharmacokinetics of local immunosuppressive drug administration. Seven mongrel dogs underwent bilateral nephrectomy and autotransplantation of one kidney to the iliac vessels. The proximal end of an infusion catheter directed into the iliac artery was tunneled to a subcutaneously placed programmable pump. A second, sampling catheter was placed with its tip in the iliac vein. Simultaneous regional (iliac vein) and systemic (jugular vein) venous concentrations of 6-mercaptopurine (6-MP), the immunosuppressive metabolite of azathioprine, were determined during a continuous 24-h intraarterial infusion (10 mg/kg/24 hr). The gradient between regional and systemic 6-MP concentrations was maximal initially when the pump was turned on, continuously decreased until steady state was reached, and disappeared immediately after the pump was turned off. The mean ratio of steady-state iliac vein to systemic 6-MP concentrations was 5.0 ± 1.4, demonstrating a pharmacokinetic advantage of continuous intraarterial 6-MP infusion to the autotransplanted kidney. The novel canine renal allograft model described herein overcomes the technical limitations of earlier models and represents a foundational step in the design of intrarenal infusion patterns of immunosuppressive agents which we expect to prolong survival of the allotransplanted kidney with minimal systemic drug exposure and side effects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015940802451
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  • 108
    Electronic Resource
    Electronic Resource
    Liquid Chromatographic Analysis of Di(2-ethylhexyl) Phthalate: Application to Pharmacokinetic Studies in the Mongrel Dog (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 10-15 
    Details
    ISSN: 1573-904X
    Keywords: di(2-ethylhexyl) phthalate ; liquid chromatographic (LC) analysis ; pharmacokinetics ; renal failure ; mongrel dog
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A high-performance liquid chromatographic (HPLC) assay was developed for the determination of di(2-ethylhexyl) phthalate (DEHP) in serum or plasma. Plasma DEHP concentrations that were measured by HPLC in specimens obtained from hemodialysis patients were in good agreement with corresponding concentrations that were measured by gas chromatography with selected ion monitoring (GC-SIM) (r 2 = 0.996). Plasma DEHP concentrations were measured after intravenous DEHP administration (1.2–4.4 mg DEHP/kg body weight) to determine the effect of bilateral ureteral ligation on DEHP elimination in the mongrel dog. DEHP plasma clearance (∼6.3 ml/min/kg), steady-state distribution volume (∼0.2l/kg), and terminal half-life (∼50 min) were unchanged in two dogs following bilateral ureteral ligation. DEHP terminal half-life and steady-state distribution volume were substantially smaller (25- to 70-fold) than reported previously in the rat or dog.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015872309411
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  • 109
    Electronic Resource
    Electronic Resource
    Peripheral pharmacokinetic parameters of levodopa/carbidopa and the on-off phenomenon in parkinsonian patients (1988)
    Springer
    Neurological sciences 9 (1988), S. 255-259 
    Details
    ISSN: 1590-3478
    Keywords: Parkinson disease ; levodopa ; pharmacokinetics ; on-off phenomenon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Sommario I principali parametri farmacocinetici periferici della associazione levodopa/carbidopa sono stati studiati in 11 volontari sani ed in 16 pazienti affetti da morbo di Parkinson in differenti stadi di malattia, con e senza fluttuazioni delle performances motorie. Dopo somministrazione per via orale di una dose standard del farmaco (levodopa 250 mg., carbidopa 25 mg.), i valori della concentrazione plasmatica massima, del tempo di comparsa del picco e dell'area sotto la curva concentrazione/tempo sono risultati simili in tutti i gruppi esaminati. La farmacocinetica periferica dell'associazione levodopa/carbidopa non è risultata essere differente nei parkinsoniani che presentavano delle fluttuazioni delle performances motorie in confronto ai pazienti con stabile risposta clinica alla terapia.
    Notes: Abstract The principal peripheral pharmacokinetic parameters of the levodopa/carbidopa association were investigated in 11 healthy volunteers and in 16 patients at various stages of Parkinson disease, with and without the on-off phenomenon. After oral administration of a standard dose of drug (levodopa 250 mg + carbidopa 25 mg) the peak plasma concentrations, peak onset time and area under the curve/time proved to be similar across the groups. There was no difference in peripheral pharmacokinetics of the association between parkinsonian patients with swings in response and those without.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02334049
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  • 110
    Electronic Resource
    Electronic Resource
    Quantitative Structure–Activity Study on Human Pharmacokinetic Parameters of Benzodiazepines Using the Graph Theoretical Approach (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 201-208 
    Details
    ISSN: 1573-904X
    Keywords: quantitative structure–activity analysis (QSAR) ; topological approach ; benzodiazepines ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The graph theoretical indices for a series of 13 benzodiazepines were calculated using a graph-path topological method. The total molecule, the ring fragments, and combinations of ring fragments were subjected to a quantitative structure–activity analysis using eight pharmacokinetic parameters. The metabolic clearance and the blood-to-plasma concentration ratios were most highly correlated with the graph theoretical indices, with R values of 0.975 and 0.938, respectively. These correlations were found when the diazepine + benzo fragment and phenyl fragment were used to calculate the graph-path indices. Terminal disposition half-life was correlated with the benzo + diazepine fragment, with R = 0.969. Truncating the graph-path codes by eliminating cycles in the total molecule markedly improved the correlation coefficients. When compared to the graph-path indices for the total molecule, the correlation coefficients for the terminal disposition half-life and metabolic clearance data rose from 0.721 to 0.935 and from 0.770 to 0.968, respectively, using the graph-path indices of the truncated molecule. Intrinsic clearance of unbound drug also was poorly correlated with the total molecule (r 〈 0.7) but rose significantly using the graph-path indices of the truncated moleucle (r = 0.971 and 0.975 for the well-stirred and parallel-tube models, respectively.)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015933527583
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  • 111
    Electronic Resource
    Electronic Resource
    Stereoselective Binding of Disopyramide to Plasma Proteins (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 316-318 
    Details
    ISSN: 1573-904X
    Keywords: disopyramide ; pharmacokinetics ; plasma proteins ; stereoisomers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015986906627
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  • 112
    Electronic Resource
    Electronic Resource
    Cimetidine Elimination from the Cerebrospinal Fluid of the Rat (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 628-633 
    Details
    ISSN: 1573-904X
    Keywords: cimetidine ; cerebrospinal fluid ; clearance ; choroid plexus ; pharmacokinetics ; transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The major goal of this study was to develop a small animal model that could be used to assess quantitatively the clearance of cimetidine from the cerebrospinal fluid (CSF) under relatively physiologic conditions. In addition, we addressed questions related to the pathways involved in the elimination of cimetidine from the CSF. We administered high and low bolus doses of cimetidine together with inulin, as a marker of bulk flow, into the lateral ventricle of anesthetized rats and sampled CSF from the cisterna magna. Principles of linear pharmacokinetic systems were applied to the data to obtain clearances from the CSF. The clearance of inulin was 2.02 ± 0.22 µl/min, which is in excellent agreement with the CSF production rate of 2.2 µl/min in anesthetized rats. The clearance of cimetidine from the CSF following the administration of a low dose was 11.8 ± 3.1 µl/min, which is in good agreement with the cimetidine CSF clearance in the rat obtained previously in studies using the technique of ventriculocisternal perfusion. A 32% decrease in the CSF clearance of cimetidine (P 〈 0.05) was observed when the high dose was administered, suggesting that CSF elimination is saturable. The clearance of inulin was unaffected by the high dose of cimetidine. This study demonstrates that the technique of lateral ventricle injection and sampling from the cisterna magna is useful in quantitatively assessing the elimination of compounds from the CSF in the rat under relatively physiologic conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015918802935
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  • 113
    Electronic Resource
    Electronic Resource
    Liquid Chromatographic Assay and Pharmacokinetics of Quazepam and Its Metabolites Following Sublingual Administration of Quazepam (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 365-368 
    Details
    ISSN: 1573-904X
    Keywords: quazepam ; metabolites ; reversed phase ; high-performance liquid chromatography ; solid-phase extraction ; plasma ; sublingual ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A reverse-phase liquid chromatographic method is described for simultaneous quantification of quazepam, and two of its metabolites, 2-oxoquazepam and N-desalkyl-2-oxoquazepam. The method uses a solid-phase extraction procedure to prepare plasma samples. After extraction, the methanolic extract is evaporated; the residue is then reconstituted in a small volume of mobile phase and chromatographed. The total chromatography time for a single sample is about 20 min. A sensitivity of 1 ng/ml for quazepam and its metabolites is attained when 1 ml of plasma is extracted. Analytical recovery of quazepam and its metabolites added to plasma ranged from 87 to 96%. The maximum within-day and day-to-day coefficients of variation for each compound at concentrations of 20 and 60 ng/ml were 7.6 and 11.2%, respectively. The method was applied to sublingual pharmacokinetic studies of quazepam in healthy volunteers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015907611170
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  • 114
    Electronic Resource
    Electronic Resource
    Comparative Pharmacokinetics of Methylprednisolone Phosphate and Hemisuccinate in High Doses (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 509-513 
    Details
    ISSN: 1573-904X
    Keywords: methylprednisolone phosphate ; methylprednisolone hemisuccinate ; pharmacokinetics ; saliva analysis ; endogenous hydrocortisone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics of methylprednisolone and two methylprednisolone esters, the phosphate and the hemisuccinate, were investigated after intravenous administration of the esters to 12 healthy male subjects in two different doses (250 and 1000 mg). Methylprednisolone was formed more rapidly from phosphate than from hemisuccinate. During the first 30 min methylprednisolone levels were three to four times higher after phosphate administration than after hemisuccinate. The mean residence time of the hemisuccinate was significantly longer and the total-body clearance lower than those of the phosphate. Whereas very little of the phosphate (mean, 1.7%) was eliminated unchanged into the urine, there were significant amounts of hemisuccinate (mean, 14.7%) excreted renally and therefore not bioavailable. Methylprednisolone saliva levels paralleled plasma levels; the average saliva/plasma ratio was 0.22. Neither phosphate nor hemisuccinate could be detected in saliva. An average of 7.2% of the administered dose was eliminated in the form of methylprednisolone in urine. Renal clearance was 24 ml/min and not dose or prodrug dependent. For both doses endogenous hydrocortisone levels were lowered after 24 hr. For the 1000-mg dose the depression was still significant after 48 hr. The results indicate that methylprednisolone phosphate results in a faster and more efficient conversion to its active form, methylprednisolone, than methylprednisolone hemisuccinate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015921408870
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  • 115
    Electronic Resource
    Electronic Resource
    Pharmacokinetics and Bioavailability of Hydromorphone: Effect of Various Routes of Administration (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 718-721 
    Details
    ISSN: 1573-904X
    Keywords: hydromorphone ; intranasal ; transdermal ; pharmacokinetics ; bioavailability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics and bioavailability of hydromorphone following various routes of administration, i.e., intravenous, oral, intranasal, and transdermal, were investigated in rabbits. Hydromorphone plasma concentrations were determined by reverse-phase high-performance liquid chromatography (HLPC). Comparison of area under the concentration versus time curve (AUC) between intravenous and oral administrations showed a low bioavailability of hydromorphone after oral administration. The nasal absorption of hydromorphone was studied by the in situ nasal recirculation technique, and the results showed that hydromorphone is well absorbed from the nasal mucosa. The transdermal permeation of hydromorphone was also evaluated for 24 hr and a steady-state plasma concentration (0.135 µg/ml) was achieved during the 6- to 24-hr periods following the application of a transdermal patch on the inner pinna of the rabbit's ear.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015959912021
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  • 116
    Electronic Resource
    Electronic Resource
    Exogenous Methemoglobin as a Cyanide Antidote in Rats (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 749-752 
    Details
    ISSN: 1573-904X
    Keywords: methemoglobin ; cyanide antidote ; cyanide poisoning ; pharmacokinetics ; rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The effects of the administration of methemoglobin (MetHb) prepared in vitro were evaluated in Sprague–Dawley rats given increasing doses of potassium cyanide (KCN). Median lethal dose (LD50) studies were conducted by giving intraperitoneal injections of KCN (in 0.3- to 0.5-ml volumes), then 2 min later administering intravenous (iv) doses of 1000, 1500, or 2500 mg/kg of MetHb through the tail vein. Control rats received an equivalent volume of saline. The resulting LD50 values for KCN were 7.4 ± 1.1, 11.7 ± 1.1, 13.9 ± 1.0, and 14.2 ± 1.0 mg/kg (mean ± SD) for the control (no MetHb) and 1000-, 1500-, and 2500-mg/kg dose groups, respectively. Additional groups of rats were given 1000, 1500, or 2500 mg/kg MetHb and submitted for necropsy. The gross finding of darkened kidneys was present in both dose groups, but became consistent and more prominent in the 2500-mg/kg dose group. Evidence of pathologic changes was not present in other organs. Single-dose pharmacokinetic studies were conducted using iv doses of 1600 and 2500 mg/kg MetHb. The elimination half-life was similar in both doses (62.6 min), but the volume of distribution (95.3 ± 7.2 and 126.3 ± 5.2 ml/kg, mean ± SE) and clearance (1.1 ± 0.1 and 1.5 ± 0.1 ml/min/kg) were significantly different (P 〈 0.05) for the 1600-and 2500-mg/kg dose groups, respectively. From these data we conclude that although MetHb is cleared from the vascular system rapidly, it may be an effective and nontoxic antidote for doses of cyanide up to twice that of the control LD50.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015928432494
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    Capillary Gas Chromatography and Thermionic N-P-Specific Detection of 13-Bis(2-chloroethyl)-l-nitrosourea (BCNU) or l-(2-Chloroethyl)-3-cyclohexyl-l-nitrosourea (CCNU) in Stability and Pharmacokinetic Studies (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 220-225 
    Details
    ISSN: 1573-904X
    Keywords: capillary gas chromatography ; analysis ; stability ; pharmacokinetics ; carmustine ; lomustine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract An expedient, rapid, and sensitive capillary gas chromatographic method for the analysis of l,3-bis(2-chloroethyl)-l-nitrosourea (BCNU) or l-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea (CCNU) in plasma is described. Separation of the underivatized nitrosourea compounds was performed on a 0.33-mm-i.d., 25-m fused-silica, SE-30 capillary column, and detection was carried out using a thermionic N–P-specific detector. The compounds were extracted from plasma with benzene with a yield of 〉87%. The assay was linear in the ranges of 0.001 to 0.5 and 0.5 to 25 µg/ml for CCNU or 0.003 to 0.50 and 0.5 to 25 µg/ml for BCNU, with correlation coefficients from 0.9914 to 0.9999 and coefficients of variation (CV) of 〈3.3%. Other antineoplastic agents did not interfere in the assay. The method was employed to study the pharmacokinetics of BCNU in rabbits. The plasma concentration-time curves were fit to a two-compartment model with a mean (SE) α, β, and total-body clearance of 2.898 (0.913) hr−1, 0.1228 (0.0179) hr−1, and 7.211 (2.862) liters/hr · kg, respectively. Further, the stability of BCNU and CCNU in solution was examined at different temperatures. Both compounds were stable in benzene or acetone (4 to 37°C) but labile in plasma even if refrigerated. The apparent rate constants for degradation of BCNU and CCNU were 0.09921 and 0.02853 hr−1 at 4°C and 5.998 and 2.553 hr−1 at 37°C, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015989612562
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  • 118
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    Dextromethorphan Pretreatment Induces Antipyrine Clearance in the Rat (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 437-439 
    Details
    ISSN: 1573-904X
    Keywords: antipyrine ; dextromethorphan ; drug metabolism ; enzyme induction ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Numerous agents that undergo extensive first-pass metabolism have been shown to inhibit oxidative drug metabolism. To examine whether this effect is related to the chemical structure or pharmacokinetic characteristics of the inhibiting agent, we determined the effect of dextromethorphan (a compound which exhibits pharmacokinetic similarities to, but is chemically dissimilar from, previously studied agents) on the disposition of antipyrine. A single oral dose of dextromethorphan hydrobromide, 100 mg/kg, 1 hr prior to antipyrine administration had no significant effect on the pharmacokinetics of this model substrate. The administration of dextromethorphan at the same dose twice daily for 3 days and an additional dose 1 hr prior to antipyrine administration resulted in a 33% increase in the clearance of antipyrine. These data indicate that dextromethorphan is capable of inducing hepatic microsomal enzymes. Studies are needed to determine if this effect also occurs upon chronic administration in humans. These data suggest that the pharmacokinetic characteristic of extensive first-pass metabolism is not necessarily associated with inhibition of drug metabolism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015940518439
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  • 119
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    Mean Residence Time Concepts for Pharmacokinetic Systems with Nonlinear Drug Elimination Described by the Michaelis–Menten Equation (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 156-164 
    Details
    ISSN: 1573-904X
    Keywords: mean residence time ; moment analysis ; pharmacokinetics ; Michaelis–Menten elimination ; compartmental models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Equations for the mean residence time (MRT) of drug in the body and related functions are derived for drugs which are intravenously administered into a one- or two-compartment system with Michaelis–Menten elimination. This MRT is a function of the steady-state volume of distribution and time-average clearance obtained from the dose and area under the curve (dose/AUC). The differences between the MRT calculated by the proposed method and by using the moment theory method (AUMC/AUC) are demonstrated both mathematically and by computer simulations. The validity of the proposed method for calculation of MRT and its relationship to the moment theory result have also been assessed by examining the percentage of the administered dose eliminated and the percentage of the total area attained at MRT and at AUMC/AUC in relation to the dose. The equations evolved should be helpful in clarifying residence time derivations and in defining the disposition characteristics and differences between linear and nonlinear systems. Direct methods are provided for calculation of Michaelis–Menten parameters based on the relationship between MRT and dose.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015960806202
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  • 120
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    Calculations and Application of Mean Residence Times for Drugs Which Demonstrate One-Compartment Distribution and Michaelis-Menten Elimination (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 196-196 
    Details
    ISSN: 1573-904X
    Keywords: mean residence time ; pharmacokinetics ; Michaelis-Menten elimination ; one-compartment model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015977209836
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  • 121
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    Pharmacokinetics, behavioral, and neurophysiological aspects of the action of 2-ethyl-6-methyl-3-hydroxypyridine in rats (1988)
    Springer
    Bulletin of experimental biology and medicine 106 (1988), S. 1104-1107 
    Details
    ISSN: 1573-8221
    Keywords: nootropic drugs ; pharmacokinetics ; behavior ; rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00840370
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  • 122
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    Determination of the water geometry in violuric acid monohydrate with a Monte Carlo simulation (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 11-17 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The positions and orientations of water molecules in violuric acid crystals have been determined with the Metropolis Monte Carlo method. The interaction potentials between water and violuric acid needed in the simulation have been developed using ab initio calculations corrected for the basis set superposition error with the C.P. technique and fitted to atom-atom pairwise potentials. The agreement between experimental data and simulation results is good, proving that the interaction potentials can be used with confidence.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090103
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  • 123
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    Acetylcholine in water: Ab-initio potential and Monte Carlo simulation (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 1-10 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Ab initio SCF-LCAO-MO computations using a minimal basis set have been carried out on the acetylcholine ion in different conformations. The rotational barrier around the C9-C8-O1-C2 dihedral angle (τ1) has been also calculated: the curve presents a broad minimum. SCF calculations have been carried out on the system Ach-water at 468 different separations and/or orientations; the interaction energies were then fitted to a pair potential function used in Monte Carlo (MC) simulations of Ach water solution. The rdfs indicate a global first hydration shell with about 38 waters. Details about the hydration shell are presented. The overall MC results indicate that for the Ach ion in water solution at room temperature relative free rotation is possible around τ1, and that Ach is well represented as a large positively charged hydrated globe with a small mobile tail free of strong interactions with the surrounding water molecules.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090102
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  • 124
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    Molecular mechanics and molecular shape. V.For Part IV, see Ref. 1. on the computation of the bare surface area of molecules (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 18-24 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: This article examines the numerical estimation of molecular surface areas within the model of overlapping atomic spheres. One has the choice of either basing the estimate on all elements that contribute to the surface, or of ignoring systematically some elements in the interatomic clefts. It is argued that the second choice, even though more approximate, implicitly improves on the model and is to be preferred. Since surface areas are not measurable, the demonstration is unavoidably roundabout, relying mostly on correlation analysis. Among the regressors occur two compounded parameters. One, ratio of the surface area of the equivalent sphere to the surface area, is interpreted as a measure of molecular globularity. It reflects the molecular axis-ratio and surface convolution. The other, ratio of the surface area to the volume, is interpreted as a measure of the global congestion of a chemical residue. Together with a measure of the local congestion at the point of attachment, it affects the steric hindrance that a residue offers. The relation between the surface area and the number of valence electrons is also discussed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090104
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  • 125
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    Explorations on the multidimensional potential energy surface of a chiral stationary phase (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 63-66 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The multidimensional potential energy surface for a soluble analog of a chiral phase is computed with MM2 and MNDO. Minimum energy conformations are located. The minimum energy reaction pathway between these forms is located, and the templating ability of these phases is described.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090108
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  • 126
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    A conformational study of a biologically active conjugated syn-oxime (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 67-74 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The conjugated system (E)-tiglaldoxime is the simplest example of a perillartine analog which exhibits sweetness with a taste potency greater than sucrose with almost no bitter aftertaste. In previous studies, the structure of this biologically active compound has been assumed to be planar with the C=C double bond trans to the C=N bond of the oxime moiety. In this article a conformational analysis of this molecule is reported. The results indicate that, although the trans conformer of the planar molecule is indeed the global minimum, other conformers lie within a few kilocalories of this minimum. Hence, other accessible conformations may be available for interaction with the receptor and, therefore, may be biologically active. The structural parameters obtained for this conjugated syn-oxime are nearly identical to those of (E)-acetaldoxime. This fact has implications for the transferability of these parameters to the more complicated perillartine analogs.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090109
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  • 127
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    Atomic physicochemical parameters for three dimensional structure directed quantitative structure-activity relationships III: Modeling hydrophobic interactions (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 80-90 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: In an earlier article8 the need was demonstrated for atomic physicochemical properties for three dimensional structure directed quantitative structure-activity relationships, and it was shown how atomic parameters can be developed for successfully evaluating the molecular octanol-water partition coefficient, which is a measure of hydrophobicity. In this work we report more refined atomic values of octanol-water partition coefficients derived from nearly twice the number of compounds. Carbon, hydrogen, oxygen, nitrogen, sulfur and halogens are divided into 110 atom types of which 94 atomic values are evaluated from 830 molecules by least squares. These values gave a standard deviation of 0.470 and a correlation coefficient of 0.931. These parameters predicted the octanol-water partition coefficient of 125 compounds with a standard deviation of 0.520 and a correlation coefficient of 0.870. There is only a correlation coefficient of 0.432 between the atomic octanol-water partition coefficients and the atomic contributions to molar refractivity over the 93 atom types used for both the properties. This suggests that both parameters can be used simultaneously to model intermolecular interactions. We evaluated the CNDO/2 gross atomic charge distribution over several molecules to check the validity of our classification. We found that the charge density on the heteroatoms in conjugated systems is strongly affected by the presence of similar atoms in the conjugation which suggests it should be incorporated as a separate parameter in evaluating the partition coefficient.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090111
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  • 128
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    Letter to the editor (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 91-91 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090112
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  • 129
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    Masthead (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988) 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090201
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  • 130
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    The dynamic “level shift” method for improving the convergence of the SCF procedure (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 107-110 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: This article is concerned with the improvement of convergence of the iterative procedure for solving the Hartree-Fock-Roothaan equations by the dynamic “level shift” method.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090203
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  • 131
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    Ab initio vibrational transition dipole moments and intensities of formaldehyde (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 95-106 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Vibrational transition dipole moments and absorption band intensities for the ground state of formaldehyde, including the deuterated isotopic forms, are calculated. The analysis is based on ab initio SCF and CI potential energy and dipole moment surfaces. The formalism derives from second-order perturbation theory and involves the expansion of the dipole moment in terms of normal coordinates, as well as the incorporation of point group symmetry in the selection of the dipole moment components for the allowed transitions. Dipole moment expansion coefficients for the three molecule-fixed Cartesian coordinates of formaldehyde are calculated for internal and normal coordinate representations. Transition dipole moments and absorption band intensities of the fundamental, first overtone, combination, and second overtone transitions are reported. The calculated intensities and dipole moment derivatives are compared to experiment and discussed in the context of molecular orbital and bond polarization theory.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090202
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  • 132
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    A molecular mechanics study of neutral molecule complexation with crown ethers (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 111-124 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Molecular mechanics methods are applied to the study of neutral molecule complexation with crown ethers. Protocols for the development of parameters necessary to describe these molecule-molecule interactions are presented. Application of these methods to the study of 1:1 and 2:1 (guest:host) complexation between acetonitrile (1), nitromethane (2), malononitrile (3) and dimethylsulfone (4) reveals positive cooperativity in formation of the 2:1 complexes in isolation.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090204
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  • 133
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    Intermediate water structures in solution of Nα-acetyl-N-methylphenylalaninamide (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 125-132 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Intermediate water structures in a solution of Nα-acetyl-N-methylphenylalaninamide[Phe(amide)2] were investigated by the energy minimization method. The results show that ninety-eight water molecules hydrate Phe(amide)2 and several kinds of cyclic structures are observed. The distribution of water molecules around Phe(amide)2 agrees with the results of molecular dynamics and monte carlo studies. The distribution of cyclic structures shows that the six-membered ones are distributed mainly at the outside of the first hydration shell.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090205
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  • 134
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    A molecular mechanics-NMR pseudoenergy approach to the solution conformation of glycolipids (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 133-147 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: We present here a protocol for the determination of oligosaccharide solution conformation from a combination of molecular mechanics calculations and NMR distance constraints treated as pseudoenergies. As an illustration of our methodology we have chosen the determination of the solution conformation of the tetrasaccharide headgroup of the glycolipid globoside. In order to test the ability of our methodology to avoid becoming trapped in local minima, we have chosen three starting structures, well displaced from one another in conformational space. The structures obtained upon convergence of the calculations with distance constraint pseudoenergies were quite similar to one another. For two of the three glycosidic linkages in globoside, the results from the calculations were virtually identical for each of the three starting structures. We also apply our protocol to a model which allows for the existence of multiple conformers in an effort to explore the possibility of conformational flexibility in the oligosaccharide headgroup of globoside.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090206
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  • 135
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    Integral data compression for FPS 64-BIT processors: Improved I/O and reduced storage (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 148-157 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Compression of two-electron integral data is used to reduce integral storage and I/O requirements with FPS M64 Series (formerly FPS-X64) processors. Schemes are developed and implemented in assembly language to compress floating-point values to a fixed-point accuracy, and unsigned integer numbers. The floating-point scheme stores only the significant bits of the mantissa and a short, biased exponent. The unsigned integers are packed into fixed-length fields just long enough to hold the largest value. The packing procedures are tested on FPS-164 and FPS-264 processors (since renamed M64/145 and M64/60 by FPS) and incorporated into HONDO to compress two-electron integral files. Reduction factors of 0.2-0.4 are obtained for floating-point compression and 0.3-0.5 for index packing, with typical overall factors around one-third. The advantages of improved I/O and storage efficiency are accompanied by a small increase in processor time to perform the packing and unpacking. Timing changes for HONDO are presented, and both packing schemes dramatically reduce SCF elapsed times with FPS-264 processors. It is concluded that compression effectively extends external storage capacities, improves I/O efficiency, and can reduce the elapsed time of I/O bound calculations.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090207
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    Parallel computation of the Moller-Plesset second-order contribution to the electronic correlation energy (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 158-170 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: We report herein, the implementation of a second-order Moller-Plesset perturbation theory (MP2) program on the IBM LCAP parallel supercomputers. The LCAP systems comprise IBM 308X hosts and 10 FPS-X64 attached processing units (APs). The APs are interconnected by a 512 Mbyte shared memory which allows rapid interprocessor communication. All the computationally demanding steps of the MP2 procedure execute efficiently in parallel. Parallel computation of two-electron integrals is accomplished by distributing the loop over shell blocks among the APs. Parallel Fock matrix formation is achieved by having each AP evaluate the contribution of its own integral sublist to the total Fock matrix. The contributions are added together on the host, and the sum diagonalized either on the host or on a single AP. The parallel implementations of the integral transformation and the MP2 calculation are less straightforward. In each case, the use of the shared memory is essential for an efficient implementation. Details of the implementations and performance data are given.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090208
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  • 137
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    Announcement (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 188-188 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090210
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  • 138
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    The rigorous computation of the molecular electric potential (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 171-187 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A method is presented for the rigorous computation of the electric potential of molecules of arbitrary shape, under the assumption of continuous linear dielectric media. The computational technique involves finding the distribution of induced polarization charge on the molecular surface, and proceeds by an application of the method of boundary elements. The surface, which separates the molecular interior (of low dielectric constant) from the highly polar solvent, is given a piece-wise analytic representation as a collection of curvilinear elements. Given a set of internal fixed charges, the distribution of polarization-charge is found as a continuous function over the surface elements, and the electric potential (including all polarization effects) is then easily computed at any point. The method is applied to a spherical interface, and to several small molecules of biological interest, including a hexapeptide. The resulting potentials show good convergence in all cases. The future application of the method to macromolecules is discussed.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090209
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  • 139
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    An efficient algorithm for solving eigenvalue problems of the type HC = SCe or FC = SCe (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 257-268 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: An efficient algorithm for solving eigenvalue problems of type HC = SCe or FC = SCe is described. This algorithm is generally faster than conventional algorithms. That is to say, this algorithm is more than 1.8 times faster than Gram-Schmidt orthogonalization and about 8 times faster than Löwdin's S-1/2 method. This algorithm is beneficial for large molecules and molecules having a high degree of symmetry. In addition, this algorithm is more compact than conventional algorithms.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090309
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  • 140
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    YETI: An interactive molecular mechanics program for small-molecule protein complexes (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 269-280 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: YETI, an interactive molecular mechanics program for drug-design applications on small-molecule protein complexes, is described. To model short-range interactions in better agreement with experimental data, its force-field energy expression includes directional potential functions for H-bonds, salt linkages, and metal ligand interactions. The program works on an internal coordinate concept and uses a conjugate-gradient minimizer. YETI is available for distribution through the author. The program has been used to model details of small-molecule binding to the enzyme human carbonic anhydrase I. The impact of the directional potential functions on the geometry of H-bonds and metal-ligand interactions is discussed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090310
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  • 141
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    Electronic Resource
    Masthead (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988) 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090401
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  • 142
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    Charge calculations in molecular mechanics. V. Silicon compounds and π bonding (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 244-256 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A previously published scheme for the calculation of partial atomic charges has been extended to include silicon, and has been parameterized for a range of Si—X bonds (X=C,H,O,F,Cl,Br). For the silicon-halogen and silicon-oxygen bonds, a comparison is made between charges calculated with and without the inclusion of π-bonding. An extensive data set consisting of experimental geometries and dipole moments for the silicon compounds considered is presented and this leads to the selection of standard Si—X bond lengths. The calculated dipole moments for the above compounds are in good agreement with those obtained experimentally only when the π charges are included. A comparison has also been made between the partial charges from this scheme and those obtained from computational methods using the Mulliken population analysis. There is considerable disagreement between the methods. Finally, the implications of the charges and structural data are considered in terms of application to zeolite systems.
    Additional Material: 8 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090308
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  • 143
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    Announcement (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 441-441 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090419
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  • 144
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    Computer generation of spectra of graphs: Applications to C60 clusters and other systems (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 406-415 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A computer code based on the Givens-Householder matrix diagonalization method is used to calculate the spectra of graphs containing a large number of vertices. The code is most general in that it can handle graphs containing 200 or more vertices. Further, the code can be used to generate the spectra of weighted graphs. The program requires as input only the neighborhood table of the graph. The spectra of many graphs are generated for the first time in less than a few minutes of computer time. Applications to a number of chemical systems including two forms (foot and hand) of the recently synthesized C60 cluster and the effect of bond alternation on these systems are discussed. In addition, the spectra of square and honeycomb lattices and the characteristic polynomials of the foot and hand forms of the C60 cluster are obtained.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090416
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  • 145
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    Correction (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 441-441 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090420
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  • 146
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    Masthead (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988) 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090501
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  • 147
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    Electrostatic interactions in molecular mechanics (MM2) calculations via PEOE partial charges I. Haloalkanes (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 424-440 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The PEOE (partial equalization of orbital electronegativity) procedure has been modified slightly and reparametrized for haloalkanes to calculate partial atomic charges suitable for evaluation of dipole moments and electrostatic energies in conjunction with molecular mechanics (MM2) calculations. Dipole moments of 66 haloalkanes are calculated with an average absolute deviation of 0.14 D from experimental values. The conformational energies of 40 compounds have been calculated and the agreement with experimental data is generally good and compares well with calculations by the IDME (induced dipole moment and energy) method. In addition, carbon and proton charges correlate well with C-1s core binding energies and 1H-NMR (nuclear magnetic resonance) shifts for halomethanes. The most striking benefit of treating electrostatics through a set of partial charges compared to the standard MM2 bond dipole approach is demonstrated by calculations on 1,4-disubstituted cyclohexanes, for which standard MM2 fails to predict the most stable conformation.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090418
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  • 148
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    Electronic Resource
    Fast algorithm for ring perception (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 455-459 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: An algorithm for finding rings in graphs is presented. The algorithm is based on the Welch-Assembly-Gibbs algorithm of Wipke and Dyott but using the homeomorphically reduced pruned graph (the extension of HRG of Balaban et al). The algorithm is able to generate both the fundamental set of rings and all possible rings in a given graph. The time and storage needs are superior to both underlying algorithms. The CPU times of the old and new algorithms are given.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090503
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  • 149
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    MC-SCF and CI calculations on four isomers of Si6H6 (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 564-577 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The four isomers of Si6 H6, hexasilabenzene (1), hexasilaprismane (2), hexasila-Dewar benzene (3), and tris-(disilanediyl) (4), have been investigated, using highly correlated wavefunctions in conjunction with a local pseudopotential approach. At the Hartree-Fock level 1 (D6h), 2 (D3h), and 3 (C2v) are established as minima by means of the harmonic vibrational frequencies. Inclusion of the most important correlation corrections via CI however, provokes a significant puckering of 1 resulting in a D3d structure, 7.1 kJ/mol below the planar conformer. The detailed analysis shows unambiguously that the propensity to puckering is due solely to the correlation contributions from the σ framework while correlation of the π electrons is of little relevance. Isomer 2 turns out to be the most stable of the investigated isomers lying 41 kJ/mol below 1 (D3d). Isomers 3 and 4 are more than 100 kJ/mol higher in energy. The Si—Si bond energies of 1 and 2 are determined as 251 and 176 kJ/mol, respectively.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090514
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  • 150
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    Electronic Resource
    Masthead (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988) 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090601
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  • 151
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    Hydrogen bonding in MM2 (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 591-595 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Hydrogen bonding is qualitatively accounted for in the early versions of the MM2 program, but not quantitatively. Experimentally, the hydrogen bonds are somewhat shorter and stronger than calculated by MM2. This has been corrected now in MM2(87), by reducing the van der Waals radius of the hydrogen involved in hydrogen bonding for that interaction only, and by increasing the van der Waals' attraction between the hydrogen and the various electronegative atoms to which it can hydrogen bond by about 1-3 kcal/mol, depending on the particular atoms involved. It is now possible to reproduce reasonably well ab initio calculations on simple amides and the methanol dimer, and experimental data on compounds in which a hydroxyl hydrogen is hydrogen bonded to an alcohol, an alkyl chloride, or to a carbon-carbon double bond.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090602
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  • 152
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    A fast, direct algorithm for the least-squares fitting of two sets of atomic coordinates of macromolecular structures (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 596-599 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: By use of rotation angle method a direct algorithm is derived, which determines the least-squares superposition that matches two sets of atomic coordinates. The program based on this algorithm runs fast. The solution obtained by this algorithm cannot be trapped by any local minimum. Testing examples are also presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090603
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  • 153
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    Surface model for ZnS thin films: ZnS clusters and chemisorption of ZnCl2 on ZnS surface (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 581-590 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Hartree-Fock valence calculations have been used to study small ZnxSy, (x,y = 1-13), clusters. The aim was to develop surface models for chemisorption processes on zinc sulfide. The calculations show that proper models should have closed ring systems with x = y. The description of the adsorption site is not very critical to the size of the cluster. The coordination to the nearest neighbors is more critical and must be described accurately. The electronic structure was shown to be localized and a minimal basis set treatment gives a qualitative picture of energy and electronic structure trends. Zinc chloride is calculated to chemisorb to a surface sulfur atom with an adsorption energy of 395 to 570 kJ/mol depending on the size of the surface model and on the basis set of the valence orbitals. The adsorption geometry is found bent and virtually independent on the modelling parameters. The calculations predict free rotation of the adsorbate. The study suggests that calculations even at the simplest level are sufficient to give a qualitative picture of the zinc chloride adsorption on zinc sulfide.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090516
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  • 154
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    Electronic Resource
    Ab initio studies of the ground-state potential energy surface of formamide (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 600-603 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Ab initio calculations employing a standard double-zeta basis set augmented with various polarization functions have been used to investigate the lowest energy region of the ground-state potential energy surface of the formamide molecule. Hartree-Fock calculations with only d polarization functions on the nonhydrogen atoms located two stable minima, that with geometry distorted from planarity having slightly lower energy; only one stable minimum with planar structure is found when p polarization functions on the hydrogens are included. In contrast optimizations, which account approximately for the correlation energy using second-order Møller-Plesset perturbation theory consistently favor a single slightly nonplanar minimum energy geometry.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090604
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  • 155
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    Electronic Resource
    Treatment of symmetry in MO calculations. II. Numerical projection operators for molecular orbitals (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 604-607 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: This article describes the numerical application of projection operators to restore the symmetry of molecular orbitals in self-consistent field (SCF) calculations when the symmetry is lost because of degeneracy or near degeneracy. The application of projection operators is particularly useful in cases of near degeneracies of three or more molecular orbitals, where it is difficult to find an effective algorithm for restoring the symmetry of molecular orbitals by orthonormal transformations.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090605
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  • 156
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    Shape group studies of molecular similarity and regioselectivity in chemical reactions (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 608-619 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The study of the qualitative and quantitative product distribution in a chemical reaction, in particular regioselectivity, is of fundamental importance. Recently, it has been shown that the regioselectivity of some Diels-Alder cycloadditions can be explained by analyzing the interrelations between electron density contours and molecular electrostatic potentials. This problem is related to a central topic of modern theoretical chemistry and biochemistry: the analysis of molecular shape. This work deals with a rigorous, algebraic method to analyze these surfaces. The procedure is based on the computation of the shape groups (symmetry-independent homology groups of algebraic topology) of the molecular surface, using either a fully analytical algorithm requiring no visual inspection, or a precise method for processing pictorial information if the latter is available. The method provides a concise description of the molecular contour surface, that can replace the usually intuitive, and somewhat subjective, visual characterization of density and electrostatic potential contours. The method is illustrated for the case of Diels-Alder reactions by considering a number of monosubstituted dienes. Extensions of the analysis to dienophiles, as well as other types of reactions are also discussed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090606
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  • 157
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    Development of a program for MCSCF calculations with large basis sets (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 627-635 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A new program named JASON2 for ab initio MCSCF calculations with large basis sets has been developed. In this program, the density-formulated super-CI CASSCF method proposed by Roos et al. was adopted in order to overcome difficult problems caused by large basis sets. The sparsity of integrals and vectorization on supercomputers were utilized as much as possible. With JASON2, we performed CASSCF calculations on a Fe-porphine complex with 232 CGTFs (contracted Gaussian-type functions). Our algorithms and timing data of the above calculations are reported.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090608
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  • 158
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    Application of SINDO1 to phosphorus compounds (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 40-50 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: SINDO1 calculations are presented for ground state geometries, heats of formation, ionization potentials and dipole moments. These calculations are based on a new parametrization of SINDO1 for second-row elements which features inclusion of 3d orbitals and zero point energies. The comparison shows an improvement over MNDO, especially for hypervalent phosphorus compounds.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090106
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  • 159
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    Application of SINDO1 to silicon, aluminum, and magnesium compounds (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 51-62 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: SINDO1 calculations are presented for ground state geometries, heats of formation, ionization potentials and dipole moments of silicon, aluminum and magnesium compounds. These calculations are based on a new parametrization of SINDO1 for second-row elements. Important features are the inclusion of 3d orbitals and the explicit evaluation of zero point energies. A comparison with MNDO data is presented.
    Additional Material: 11 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090107
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  • 160
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    Molecular mechanics parameters for organosilicon compounds calculated from ab initio computations (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 25-39 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Molecular structures of 26 organosilicon compounds have been optimized using ab initio calculations at the 3-21G* (modified) level. From these optimized structures, the internal coordinates have been deformed and the variation of the total molecular energy has been studied. Parameters for stretching and bending deformations are reported herein. The bending potential for the Si—O—Si bond which has an unusual flexibility is also included. Nonbonding interactions are described in terms of steric and electrostatic potentials. For systems which do not include bond resonance effects, torsional behavior is well described by steric potentials with van der Waals radii 20% larger than the previous values and simple electrostatic potential (monopole-monopole) with net atomic charges obtained from ab initio or Extended Huckel Theory calculations. The nonbonding potentials, as defined in this study, have an advantage in that they allow for the computation of torsional barriers without torsional potentials, in the case of single bonds where no additional electronic effects interfere. As an example, it is shown that no torsional potentials are necessary to estimate the torsional barriers in the case of ethane. The newly defined potentials are used to study the torsional barrier in hexamethyldisiloxane and the conformation of octamethylcyclotetrasiloxane (D4). The most stable calculated conformation of D4, coincides with the experimentally determined structure. This study shows that the most stable conformation is determined by the steric repulsion of methyl groups.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090105
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  • 161
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    The computation of floating functions and their use in force constant calculations (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 75-79 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: It is shown how standard computer programs for calculating the equilibrium geometry of a molecule may be adapted to yield floating functions. These functions satisfy the Hellmann-Feynman theorem and so lead to simple electrostatic interpretations of intramolecular forces and vibrations. The theory is illustrated by detailed calculations for the water molecule.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090110
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  • 162
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    Masthead (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988) 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090301
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  • 163
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    On velocity scaling in molecular dynamics simulations (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 200-203 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The effect of scaling the molecular velocities to a fixed total energy in molecular dynamics simulations within the (N,V,E) ensemble has been investigated. The effect of using different time steps is also discussed. It is found that, even for small time steps, velocity scaling has a substantial influence on the resulting molecular trajectories, velocities, and forces. Furthermore, velocity rescaling and larger time step seem to have an additive effect on the calculated trajectories, but not on the average thermodynamic properties, such as temperature, pressure, and energy.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090303
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  • 164
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    Effect of the substituents on the conformational behavior of five-membered rings: Application to the cis- and trans-2,5-dimethoxytetrahydrofuran (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 189-199 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A model is proposed which assumes that the pseudorotational potential in five-membered rings is given by the combination of contributions from the unsubstituted ring, from the individual substituents and from interactions between pairs of substituents. The application of this model to the potentials calculated by the MM2 force field for the cis and trans-2,5-dimethoxytetrahydrofuran shows that the contributions from the individual substituents explain the main features of the potentials of these disubstituted rings. The pseudorotational analysis from vicinal proton spin-spin coupling constants 3JHH confirms the realibility of the MM2 potentials.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090302
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  • 165
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    Computer generation of characteristic polynomials of edge-weighted graphs, heterographs, and directed graphs (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 204-211 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The computer code developed previously (K. Balasubramanian, J. Computational Chem., 5, 387 (1984)) for the characteristic polynomials of ordinary (nonweighted) graphs is extended in this investigation to edge-weighted graphs, heterographs (vertex-weighted), graphs with loops, directed graphs, and signed graphs. This extension leads to a number of important applications of this code to several areas such as chemical kinetics, statistical mechanics, quantum chemistry of polymers, and unsaturated systems containing heteroatoms which include bond alternation. The characteristic polynomials of several edgeweighted graphs which may represent conjugated systems with bond alternations, heterographs (molecules with heteroatoms), directed graphs (chemical reaction network), and signed graphs and lattices are obtained for the first time.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/jcc.540090304
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    A theoretical study of the rotational isomers of nitrosomethanol by semiempirical (AM1) and ab initio methods (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 212-221 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The conformational potential energy surface as a function of the two internal torsion angles in C-nitrosomethanol has been obtained using the semiempirical AM1 method. Optimized geometries are reported for the local minima on this surface and also for the corresponding points on the HF/6-31G, 6-31G*, and 6-31G** surfaces. All methods predict cis and trans minima which occur in degenerate pairs, each pair being connected by a transition state of Cs symmetry. The AM1 structures are found to compare well with the corresponding ab initio structures. Ab initio HF/6-31G and HF/6-31G* harmonic vibrational frequencies are reported for the cis and trans forms of nitrosomethanol. When scaled appropriately the calculated frequencies are found to compare well with experimental frequencies. The ab initio calculations predict the energy barrier for cis → trans isomerization to be between 5.8 and 6.5 kcal/mol with the trans → cis isomerization barrier lying between 2.3 and 6.5 kcal/mol. The corresponding AM1 energy barriers are around 1 kcal/mol lower in energy. The ab initio calculations predict the barrier to conversion between the two cis rotamers to be very small with the AM1 value being around 1 kcal/mol. Both AM1 and ab initio calculations predict interconversion between trans rotamers to require between 1.2 and 1.4 kcal/mol.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090305
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  • 167
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    Application of finite-element method to the two-dimensional Schrödinger equation (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 222-231 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: An algorithm to solve the two-dimensional Schrödinger equation based on the finite-element method is proposed. In our scheme, the molecular Hamiltonian with any arbitrary internal coordinate system can be solved as easily as with the Cartesian coordinate system. The efficient computer program based on the algorithm was developed on the HITAC S-810 supercomputer. The performance of the program is examined in the following test problems; (1) free particle in a box, (2) linear triatomic molecule with two equal force constants, (3) coupled Morse oscillators, (4) Henon-Heiles potential, (5) H3O+ symmetric vibrational modes. The algorithm is demonstrated to be very suited for the vector-type supercomputer.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090306
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    A novel approach to the use of graph theory in structure-activity relationship studies. Application to the qualitative evaluation of mutagenicity in a series of nonfused ring aromatic compoundsAll communications regarding the article should be made with Gilles Klopman. (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 232-243 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: In this article we describe a novel approach to the application of graph theory in structure-activity relationship studies. An information-theoretical topological index for the vertices of a molecular graph has been used for the qualitative evaluation of the mutagenic activity of a series of nonfused ring aromatic compounds. The use of a vertex index contrasts with the conventional approach of using a topological index for the entire molecule. The idea is to identify regions, or substructures in the molecules (molecular graphs) which may be used to determine certain biological activity of chemical compounds. The results obtained in this paper indicate that the present approach is capable of classifying the mutagenic activity of the compounds under consideration and may find useful application in structure-activity relationship studies of diverse bioactive compounds.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/jcc.540090307
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    The stepwise heats of hydrogenation of barrelene, an ab initio studyTwo of us (LRS, KMF) dedicate this paper to our co-author and colleague, Norman L. Allinger, on the occasion of his sixtieth birthday. (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 281-287 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Ab initio Hartree-Fock calculations at the 6-31G*//3-21G level of theory are reported for bicyclo[2.2.2]-2,5,7-octatriene (barrelene), 1, bicyclo[2.2.2]-2,5-octadiene, 2, bicyclo[2.2.2]-2-octene, 3, and bicyclo-[2.2.2]octane, 4. The stepwise heats of hydrogenation of 1 were found to be 38.1, 31.8, and 28.4 kcal/mol, respectively. The unusually large heat of hydrogenation for the first double bond is attributed to the destabilizing electronic effects involving the interaction of the three double bonds of 1.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090402
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  • 170
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    Charge calculations in molecular mechanics IV: A general method for conjugated systems (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 288-297 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A general method for calculating pi charges based on the Hückel molecular orbital (HMO) approach is incorporated into an existing scheme for calculating partial atomic charges in saturated systems. The parametrization of the Hückel coulomb and resonance integrals is given based on (a) the CNDO pi densities and (b) the observed molecular dipole moments. The results for these two schemes are compared both with other theoretical methods and also with the observed dipole moments of a variety of conjugated and aromatic compounds. The dipole moment (DM) parametrization gives in general more consistent results and is to be preferred. The compounds studied include substituted olefins and aromatics (with substituents R, F, Cl, Br, I, OR), aldehydes, ketones, acids, esters, amides, and the heterocyclic ring systems of furan, pyrrole, pyridine, and indole.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090403
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  • 171
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    Combinatorial models and algorithms in chemistry. Search for isomorphisms and automorphisms of molecular graphs (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 303-314 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: An algorithm for the recognition of all isomorphisms for any pair of labeled graphs as well as for generation of the graph group is described. Some results obtained with computer realization of the suggested algorithm are briefly discussed.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/jcc.540090405
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  • 172
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    Calculating the electrostatic potential of molecules in solution: Method and error assessment (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 327-335 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: We present a numerical method for calculating the electrostatic potential of molecules in solution, using the linearized Poisson-Boltzmann equation. The emphasis in this work is on applications to biological macromolecules. The accuracy of the method is assessed by comparisons with analytic solutions for the case of a single charge in a dielectric sphere (Tanford-Kirkwood theory), which serves as a model for a macromolecule. We find that the solutions are generally accurate to within 5%. Larger errors occur close to the charge and the dielectric boundary, but the maximum error found at ion-bonding distance (3 Å) from a charge close to the boundary (1 Å deep) is only ∼15%. Several algorithmic improvements, described here, contribute to the accuracy of the method. The programs involved compose a coherent software package, called Del Phi, which goes from a Brookhaven Protein Data Bank format file to calculated electrostatic fields.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090407
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  • 173
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    An algorithm for the location of branching points on reaction paths (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 465-475 
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    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A branching point is a point on a reaction path leading from reactants to products (via a transition state) at which it is energetically favorable for the system to break symmetry. Such a point can be defined in terms of normal modes along the reaction path and corresponds to zero curvature (a zero Hessian eigenvalue) along a symmetry-breaking mode. An effective method for the location of such points is presented and realized in an efficient, practical algorithm designed for use in the ab initio program package Gaussian 82.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090505
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    Rotation around the C1—C2 bond of propylamine, an ab initio studyThe two of us (LRS, SP) dedicate this article to our coauthor and colleague, Norman L. Allinger, on the occasion of his sixtieth birthday. (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 460-464 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Ab initio Hartree-Fock calculations at the 6-31G*//6-31G* and MP3/6-31G*//6-31G* levels of theory are reported for propylamine. All ten stationary points needed in a description of the rotation around the C1-C2 bond have been located on the 6-31G* surface and each of these points has been examined at the MP3 level.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090504
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    Efficient calculation of electrically based intermolecular potentials of weakly bonded clusters (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 476-487 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Electrical interactions between molecules are important effects in weak and long-range attractions. With quantum mechanical techniques now capable of yielding values of all multipole polarizabilities, hyperpolariabilities, and beyond, exhaustive treatment of electrical interaction is no longer out of the question. An efficient computational strategy is presented for the evaluation of electrical interaction energies to any desired level for small, medium, and large (ca. 100 molecules) clusters. With incorporation of repulsive, hard-wall potentials, global surfaces may be examined. Example calculations are presented.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090506
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  • 176
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    Ab initio vibrational analysis of three rotamers of 2-propen-1-imine, H2C=CH—HC=N—H, and methanimine, H2C=N—H (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 443-454 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The results of complete Hartree-Fock (HF)/6-31G geometry optimization and HF/6-31G//HF/6-31G force fields evaluations of three rotamers of the H2C=CH-HC—N—H molecule (s-trans-d-trans-, s-trans-d-cis- and s-cis-d-trans-2-propen-1-imine) and the H2C=N-H molecule are reported. All three conformers were found to be planar with the s-trans-d-trans conformer lowest in energy. This was corroborated by further complete optimizations of the geometries of the s-trans-d-trans and s-trans-d-cis conformers at the HF/6-31G*(5D) level as well as single-point MP4/6-31G*//HF/6-31G*(5D) calculations. The assignment of the vibrational frequencies of the propenimine rotamers and some isotopomers of methanimine are also reported. The majority of the experimental frequencies of propenimine in the gaseous phase are found to belong to the s-trans-d-trans form, but a few frequencies are attributed to the high-energy s-trans-d-cis conformer.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/jcc.540090502
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    Barriers to rotation adjacent to double bonds. 4. Effect of basis set on structures, and of electron correlation on relative energies (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 488-494 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The optimized geometries for the rotamers of propanal, 2-butanone, isobutyraldehyde, methyl isopropyl ketone, and isobutyric acid obtained using the 3-21G and 6-31G* basis sets are compared, and systematic changes are noted. The relative 6-31G* energies using the 3-21G and 6-31G* geometries are generally the same within 0.1 kcal/mol. The effect of electron correlation on the relative energies is generally small. These and related data show that 6-31G* relative energies obtained using 3-21G geometries are generally satisfactory when studying rotation about C—C bonds. However, this is not the case for C—O bonds. The calculated relative energies of isomeric compounds are reproduced only with the full MP4 correction for electron correlation.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090507
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    Basis set effects and the choice of reference geometry in ab initio calculations of vibrational spectra (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 495-504 
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    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Tatewaki and Huzinaga's [J. Comput. Chem. 1, 205 (1980)] basis sets, constructed to minimize superposition error, were used to calculate infrared (IR) frequencies and intensities. They were found inferior to Pople bases such as 3-21G and 6-31G*. The question of whether a theoretical vibrational spectrum should be computed at experimental or theoretical bond lengths was also investigated. If the magnitude of the correlation energy increases with bond length, Hartree-Fock bond lengths are expected to be shorter than experimental, and frequencies computed there will be higher than those computed at experimental lengths. Conversely, if this magnitude decreases with R, computed lengths should be longer than experimental and should give lower computed frequencies.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jcc.540090508
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  • 179
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    General algorithm for calculating vibrational-librational states of a rigid molecule in an external potential. Application to benzene-water complexesThe Fortran code for the algorithm discussed will be supplied on request. (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 505-517 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A general algorithm of calculating the eigenstates of a rigid molecule trapped in an external potential is reported. The wave function and the potential are expanded about a common reference configuration. The expansion coefficients of the wave function are variationally determined. Contracted basis functions may be used to restrict the number of expansion coefficients. The use of the algorithm is illustrated by calculations of intermolecular eigenstates of benzene-water complexes.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090509
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  • 180
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    Electron donor-acceptor complexes: Evaluation of MNDO as a computational tool to probe intermolecular interactions (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 539-553 
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    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Donor-acceptor pairs form EDA complexes that exist as conformational isomers exhibiting different ground-state and photochemical properties. We have sought a rapid, general, and accurate quantum mechanical computational method to generate potential energy surfaces that are representative of the donor-acceptor intermolecular interactions at the self-consistent field (SCF) level. The semiempirical molecular orbital (MO) method MNDO has been compared to ab initio methods to assess its behavior with respect to energy, dipole moment and ionization potential shifts. MNDO correctly distinguishes between repulsive and bound EDA complex states at the SCF level and produces potential curves that are smooth and free of spurious minima or cusps. MNDO curves are systematically more repulsive than those for ab initio STO-3G calculations; calculated interaction energies exhibit a mean absolute deviation of 2.90 kcal/mol. MNDO appears to provide a reliable qualitative estimate of the nondispersion portion of the interaction energy. Limitations and errors arising from minimal basis sets, single determinants, and neglect of dispersion are discussed.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jcc.540090512
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    Determination of the major solution conformation of tyrocidine A, using molecular mechanics energy minimization and NMR-derived distance and torsion angle constraints (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 522-538 
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    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Molecular mechanics energy calculations coupled with nuclear magnetic resonance-determined distance and torsion angle constraints have been used to determine the three-dimensional structure of tyrocidine A, a cyclic decapeptide which exists largely as a single conformation in solution. Two open-chain polyalanine models were used to represent separate halves of the peptide backbone and a combinatorial method of searching conformation space used to generate candidate structures consistent with experimental distance constraints. These structures were energy-minimized using the AMBER molecular mechanics forcefield and the resulting conformations classified by factor analysis of their Cartesian coordinates. Representative low-energy conformers of the two halves of the backbone were fused together and two candidate conformations of the completed backbone refined by further minimization using both distance and torsional constraints. Side chains were then added as their experimentally preferred rotamers and the whole molecule minimized without constraints to give the final model structure. This shows type II' and III ß turns at residues 4-5 and 9-10, respectively, coupled by twisted antiparallel strands which show hydrogen bonds between all four pairs of opposing peptide groups. The backbone conformation of residues 2-6 closely resembles that found in the crystal structure of gramicidin S.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/jcc.540090511
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    Ab initio pseudopotential study of the fluxional behavior in tetrahydroborate complexes. Many-body contributions to the energy barriers of NaBH4, AlH2BH4, and GaH2BH4 (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 518-521 
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    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The relative stabilities of the bidentate and tridentate configurations of the complex hydrides NaBH4, AlH2BH4, and GaH2BH4 have been computed both at the Hartree-Fock and post-Hartree-Fock levels using the ab initio pseudopotential method. For both compounds correlation effects favor the configurations with the highest coordination of the metal. The changes with respect to HF results are not very large, so that second-order perturbative computation of correlation energy is sufficient to give accurate results.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090510
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    Shape characterization of some molecular model surfaces (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 554-563 
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    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: An algebraic method is proposed to represent and to characterize in a concise way the shape of an arbitrarily asymmetrical surface composed from spherical pieces. These surfaces include, among others, the well-known van der Waals surfaces. The procedure is based on the computation of a hierarchy of homology groups (“shape groups”) of algebraic topology, for a family of objects defined by the original surface. The technique uses the same input information as that necessary to produce a graphical display of the molecular surface. However, the actual figure is not necessary for the computation of the shape groups. Only a classification of the points on the surface, according to their position with respect to the intersection of two or more spheres, is needed. The result is a purely algebraic characterization that can be obtained and stored by a computer, and that may prove to be useful when comparing shapes of different molecules. Illustrative examples are provided for different molecules, as well as for different conformations of the same molecule.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jcc.540090513
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    On the second-order terms of perturbation theory (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 578-580 
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    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090515
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    Analytic solutions to sets of first-order rate equations with up to six rate constants using a symbolic computer language SMP and application to biochemical kinetics (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 674-683 
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    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A symbolic computer language SMP* is employed to analytically solve sets of first-order linear differential equations which occur in kinetic rate-reaction studies. The solutions studied are fully analytic functions of time and the rate constants. Two typical systems are studied: the first contains four species and four rate constants, corresponding to four parallel and consecutive first-order reactions; and the second contains four species and six rate constants, including two additional reverse reactions. These analytic functions allow insight into the mechanism, analytic expressions for the rate constants, and more rapid and precise solutions for the species concentrations than a completely numerical solution of the differential rate equations themselves. The results of the first system are applied to a recent experimental study of enzyme kinetics in which constituent amino acid residues of an enzyme are photooxidized and the corresponding catalytic activity measured with time. A second application of the SMP gives rise to a rapid semianalytic method for obtaining the values of the four and six exponentially nonlinear rate constants from the experimental data.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jcc.540090613
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  • 186
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    Simulation of wave-propagation in three dimensions using fortran on the CYBER 205 (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 689-701 
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    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The description of a FORTRAN program made on CYBER 205 is presented for solving reaction-diffusion equations.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/jcc.540090615
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    Electronic Resource
    Toward automating the process of determining polypeptide secondary structure from 1H NMR data (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 662-673 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A computer program has been constructed to perform a qualitative analysis of nuclear magnetic resonance data on polypeptide sequences to identify α-helical and β-strand secondary structure segments. The criteria embodied within the program are some of those which have proven useful in studies where secondary structure was described by visual interpretation of NOESY and COSY spectra. Other rules used in these studies, however, remain implicit in the description of the analysis or are ill-specified, so that they are not used uniformly across studies. The structure of the program presented allows the rules and assumptions of this qualitative method to be modeled explicitly and used consistently, allowing a flexible and understandable framework for investigating both proteins of interest and the method involved in the analysis. The system has been tested on data sets from twelve proteins and was in agreement with 97% of the ø-helical regions of the proteins when compared to the reports in the literature, as well as with 95% of the residues included, and in agreement with 96% of the β-strand regions of the proteins, as well as with 90% of the residues included in them. Over the entire primary sequence, the system was in agreement with the placement of 83% of the residues in the major secondary structures.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090612
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  • 188
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    Electronic Resource
    Masthead (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988) 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090701
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  • 189
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    Electronic Resource
    Comparison of semiempirical MO methods for open-shell systems (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 702-707 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The use of AM1, MNDO, and MNDOC semiempirical MO methods for calculation of heats of formation and ionization potentials of a series of 38 radicals are described. AM1 and MNDO calculations are reported using both half-electron (HE) and Unrestricted Hartree Fock (UHF) wavefunctions. Results show the MNDOC method to give lowest overall errors, being slightly better than the HE-AM1 method. In all cases, the AM1 method shows considerable improvement over MNDO.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090616
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  • 190
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    Electronic Resource
    A molecular mechanics study of the Si—O bond and alkyl-silanes (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 709-718 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The standard MM2 force field and program have been modified to include Si—O groups, the force constants being derived from ab initio wavefunctions, and using partial atomic charges calculated from the empirical algorithm CHARGE2. Molecular mechanics calculations have been carried out on disiloxane, dimethoxy-dimethylsilane, methyl silyl ether, and cyclotrisiloxane, and reasonable agreement has been obtained between the observed and calculated geometries. In addition, the energies obtained using the modified force field have been tested against experimental data on alkyl silanes where energetic and structural information is available. Again good agreement is obtained. The application of the force field to extended Si—O systems will also be discussed.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090702
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  • 191
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    Electronic Resource
    Validity of the Hammond postulate and constraints on general one-dimensional reaction barriers (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 728-744 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The Hammond postulate is a useful, qualitative tool that interrelates structural similarities between reactants, transition structures, and products with the exo- or endothermicity of reactions. It applies to most chemical reactions, although several exceptions are known. In this study the following problem is addressed: is it possible to formulate conditions for the validity of the quantitative Hammond postulate in terms of simple physical quantities characteristic to the molecules involved? A detailed analysis is given for the conditions of validity of the postulate, in terms of bounds on the internal forces and force constants of nuclear arrangements encountered along a reaction path. We have determined a broad class of constraints on barrier shapes that must be satisfied in order to obtain a critical situation that violates the Hammond postulate: a reactant-like transition structure (“transition state”) for endothermic reactions, and a product-like one for exothermic reactions. The general constraints are formulated in terms of physically meaningful quantities: (i) energy differences, (ii) restrictions on slopes (e.g., an upper bound on internal forces), and (iii) restrictions on curvatures (e.g., upper bounds on force constants) along potential curves.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090704
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  • 192
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    Electronic Resource
    Representation of the molecular electrostatic potential by atomic multipole and bond dipole models (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 745-763 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Ab initio wave functions using the 6-31G** basis set were calculated for a set of 24 organic molecules which included saturated and unsaturated hydrocarbons, fluoro compounds, hydroxyl and ether compounds, carboxylic acids, esters, amines, carbonyl compounds, amides, and N-methyl amides. The electric potential on a grid within a van der Waals shell around each molecule was calculated directly from the wavefunctions. The electric potential values were modeled by placing multipoles up to quadrupoles at atomic sites. The electric potential was well fitted by a model which included atomic monopoles, dipoles, and quadrupoles. Also, the electric potential was modeled by placing dipoles at bond centers. This bond dipole was either allowed to point in any direction, or was restricted to the bond direction. In general the values shown for the monopoles and the values and directions for the bond dipoles were as expected from considerations of electronegativity and reactivity. For the general bond dipole model in a number of cases the direction of the bond dipole was not parallel to the bond direction. It is suggested that this is an artifact caused by the effects of lone pair electrons or electron delocalization on the model. The restricted bond dipole model fitted the electric potential about as well as the atomic monopole model. Atomic monopole values (net atomic charges) and bond dipole values for various atoms, functional groups, and bonds are discussed. Since bond-dipole interaction energy has better long-range convergence than monopole interaction energy, bond dipoles are a useful alternative to atomic monopoles.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090705
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  • 193
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    Electronic Resource
    Applications of the model potential method to transition metal compounds (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 719-727 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Model potential parameters and basis sets, presented previously for the transition metal atoms Sc through Hg, are tested in calculations of the transition metal compounds (CuF, CuCl, Cu2, TiCl4, ZrCl4, CoF63-, CoF62-, AgH, AuH, CrF6, ScO, ZrO, Cr2, Mo2). Calculated values of the bond distances, vibrational frequencies, and some transition energies (for Cu2 and CoF62-) are compared with those given by all-electron calculations with basis sets of high quality. Singlet-triplet splittings in Cu2 and correlation energies in CrF6n- (n = 0, 1, and 2) are also examined. The satisfactory results obtained by these calculations strongly support the contention that the model potential method is a reliable and economical alternative to the ab initio Hartree-Fock-Roothaan method.
    Additional Material: 8 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090703
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  • 194
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    Electronic Resource
    A simple method for calculating reliable atomic charges in large molecules (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 764-770 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Modifications are made to a previously developed scheme for calculating atomic charge which uses orbital electronegativity and which requires minimal calculational effort. The introduced changes are a result of deficiencies noted in the earlier method which were due to an inadequate accounting of effects from neighboring atom charges. Results obtained using the modified scheme for both model compounds as well as larger molecules of interest to biochemistry are compared to previous results and also to several levels of ab initio calculations. It is shown that a definite improvement is obtained and that the present method gives very good correlations with each calculational level. Comparisons are also made with other methods that use electronegativity theory. It is shown that the present scheme represents a definite improvement over alternate orbital electronegativity methods and is roughly comparable to a higher level scheme that utilizes atomic electronegativity values. A discussion comparing the latter method with the present one is included. Because of the small amount of calculational effort involved, the results indicate that the present method could be quite useful in providing reliable atomic charges for large molecular systems.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090706
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  • 195
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    Electronic Resource
    Computation of one and two electron spin-orbit integrals (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 771-778 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Methods for the computation of one- and two-electron spin-orbit integrals over Gaussian-type basis functions are presented. We show that existing nuclear-attraction and electron-repulsion integral codes can be readily adapted for the efficient evaluation of spin-orbit integrals; in particular, one can take advantage of recent advances in the computation of derivative integrals. Recurrence relations for the nuclear attraction integrals are also developed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090707
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  • 196
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    Electronic Resource
    Ab initio calculations relevant to the mechanism of chemical carcinogenesis by N-nitrosamines. VIII. Effects of hydration on various reactions involved in the formation and metabolism of N-nitrosamines (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 779-783 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A number of important reactions involved in the formation and metabolism of N-nitrosamines have been studied using a modified reaction field method which treats the solute quantum mechanically and the solvent as a polarized dielectric.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090708
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  • 197
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    Electronic Resource
    Calculation of the one-electron two-center integrals with STOS using recurrence-based algorithms (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 790-797 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: We present a new algorithm for the calculation of two-center one-electron integrals with STOS based on two sets of recurrence relations. The first one enables us to calculate any of these integrals in terms of a few “basic integrals.” Furthermore, these basic integrals are written in terms of certain auxiliary functions which can be obtained through the second set of relations from only two starting values. We give also simple formulas for these starting quantities. Finally, the numerical stability, accuracy, and speed of the different steps of the algorithm are analyzed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090710
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  • 198
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    Electronic Resource
    Similarity and clustering in chemical information systems, by Peter Willett, research studies press, Letchworth, Hertfordshire, England, 230 + xii pp, $54.95, (1987) (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 798-798 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090711
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  • 199
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    Electronic Resource
    Chemometrics, by M.A. Sharaf, D.L. Illman, and B.R. Kowalski, Wiley, New York, 1986, 332 pp. $49.95 (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 799-800 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090712
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  • 200
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    Electronic Resource
    A new tool for the rapid estimation of charge distribution (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 9 (1988), S. 893-904 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A method has been developed which uses a rapid connectivity-based calculation to give a reasonable approximation of CNDO σ and π charges for most carbons in saturated and unsaturated hydrocarbons. In this calculation an appropriately parameterized Del Re method is used to calculate the σ charges, and if the molecule is unsaturated, these charges are used to modify the diagonal elements in a Hückel matrix, reducing the normally exaggerated π charges. The CNDO charges are obtained from “single point” calculations, using optimized geometries derived from molecular mechanics. The Del Re/Hückel method is most reliable where steric and hyperconjugative effects are absent.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540090811
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