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  • 2000-2004
  • 1985-1989  (1,339)
  • 1920-1924
  • 1988  (1,339)
  • Analytical Chemistry and Spectroscopy  (1,301)
  • Magnetic resonance imaging
Source
Material
Years
  • 2000-2004
  • 1985-1989  (1,339)
  • 1920-1924
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Choice of surgical approach in orbital space occupations — an interdisciplinary problem (1988)
    Springer
    Neurosurgical review 11 (1988), S. 239-244 
    Details
    ISSN: 1437-2320
    Keywords: Magnetic resonance imaging ; orbital neoplasms ; radiography ; surgical therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract During the last two and a half years 60 patients with orbital space occupying neoplasms were treated surgically at the Department of Maxillo-facial Surgery of the University Clinic of Essen. With modern imaging techniques exact information on the location and extent of space occupation was available before the operation. Therefore the surgical approach could be optimized. Despite the various and sometimes inaccessible tumor locations, transcranial operation was only necessary in six patients. In the remaining 54 patients anterior orbitotomy allowed either a definitive tumor therapy or histological verification of the diagnosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01741416
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  • 2
    Electronic Resource
    Electronic Resource
    Ecchordosis physaliphora arising from the cervical vertebra, the CT and MRI appearance (1988)
    Springer
    Neuroradiology 30 (1988), S. 81-83 
    Details
    ISSN: 1432-1920
    Keywords: Computed tomography ; Magnetic resonance imaging ; Ecchordosis physaliphora ; Spinal cord
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The authors report a rare case of ecchordosis physaliphora arising from C2, manifested with clinical symptoms, with the findings of CT scans and MRI.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341951
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  • 3
    Electronic Resource
    Electronic Resource
    Gadolinium-DTPA as a contrast agent in magnetic resonance imaging of the brain (1988)
    Springer
    Neuroradiology 30 (1988), S. 145-154 
    Details
    ISSN: 1432-1920
    Keywords: Magnetic resonance imaging ; Gadolinium-DTPA ; Intracranial disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary One hundred patients with CT-proven intracranial disease have been studied by magnetic resonance imaging (MRI) before and after intravenous injection with Gadolinium-DTPA (Gd-DTPA), in order to assess the role and clinical efficacy of Gd-DTPA. T2-weighted spin echo sequences, although sensitive to the detection of intracranial disease, in general fail to differentiate macroscopic tumour from oedema. Following Gd-DTPA, T1-weighted spin echo sequences in primary tumours demonstrated a variable degree of contrast enhancement unrelated to histological type. Small tumours, especially acoustic neuromas and meningiomas in the posterior fossa, were rendered more conspicuous. Optimum time for scanning was between five and 25 min following injection for all lesions except those adjacent to normal enhancing structures such as nasal/sinus mucosa and pituitary gland when delayed scans up to 45 min were necessary. No differences were observed between the 0.1 and 0.2 mmol/kg Gd-DTPA concentrations used and no complications attributable to Gd-DTPA were detected. Clinical advantages of Gd-DTPA include shorter scan times, macroscopic tumour/oedema separation and improved detection of certain tumours, particularly acoustic neuromas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00395616
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  • 4
    Electronic Resource
    Electronic Resource
    MRI parameters in multiple sclerosis patients (1988)
    Springer
    Neuroradiology 30 (1988), S. 219-223 
    Details
    ISSN: 1432-1920
    Keywords: Multiple sclerosis ; Computed tomography ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Magnetic resonance imaging (MRI) findings of 20 patients with clinically definite multiple sclerosis (MS) are presented. The studies were performed on a 0.5 Tesla magnet using spin-echo technique. Analysis of the MRI findings included detailed linear measurements of the ventricular and the subarachnoid spaces and reading of the intensity of the grey and white matter and intensity of the MS plaques. The plaques were sorted according to their number and size. The younger patients (20–40 years) had overall more plaques than the older ones (over 40 years). The small plaques were the most numerous and the large ones were the least common. Statistically significant association was found between the number of plaques and the cella media width. The intensity ratios between the nonplaque white matter/grey matter showed a significant correlation with the ventricular score. A significant negative correlation was found between the antero-posterior diameter of the spinal cord and the number of MS plaques in the brain. The plaque/white matter ratio had a significantly negative correlation with the cervical cord's width.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341832
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  • 5
    Electronic Resource
    Electronic Resource
    MR imaging of dural arteriovenous malformations with ocular signs (1988)
    Springer
    Neuroradiology 30 (1988), S. 390-394 
    Details
    ISSN: 1432-1920
    Keywords: Arteriovenous malformation ; Magnetic resonance imaging ; Cavernous sinus ; Dura mater
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Four patients with dural arteriovenous malformation (AVMs) draining into the cavernous sinus, who presented ophthalmic manifestations, were studied by magnetic resonance (MR) imaging. In all patients signal decrease in the involved cavernous sinus was demonstrated in coronal spinecho (SE) imaging. It is attributable to rapid venous flow in the sinus, and this “high velocity signal loss” is a fairly pathognomonic finding in this condition. We stress the validity of MR imaging in the primary diagnosis of dural AVMs with ophthalmic symptoms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00404103
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  • 6
    Electronic Resource
    Electronic Resource
    MRI and hydrocephalus in childhood (1988)
    Springer
    Neuroradiology 30 (1988), S. 310-314 
    Details
    ISSN: 1432-1920
    Keywords: Hydrocephalus ; Spinal cord tumours ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In six young patients presenting with raised intracranial pressure during the period of a year, CT revealed the presence of hydrocephalus, but not the cause. Magnetic Resonance Imaging not only shwed the site and nature of the obstructing lesion, but also detected additional clinically silent spinal cord tumors in five of the patients. The place of MRI in the diagnosis of diseases involving the region of the cranio-cervical junction and in the elucidation of “unexplained hydrocephalus” is considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00328181
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  • 7
    Electronic Resource
    Electronic Resource
    Ossification of the ligamentum flavum (1988)
    Springer
    Neuroradiology 30 (1988), S. 571-573 
    Details
    ISSN: 1432-1920
    Keywords: Magnetic resonance imaging ; Ossification of ligamentum flavum ; Thoracic myelopathy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of thoracic myelopathy due to ossification of the ligamentum flavum is presented. A fifty-five year old female complained of sensory and motor disturbance of lower limbs. Neuroradiologically, in addition to ossification of the posterior longitudinal ligament throughout the spines, ossified ligamenta flava were found at the Th10–11 level and magnetic resonance imaging (MRI) clearly showed the spinal cord compressed at the same level by a low-intensity-signal lesion. Laminectomy and removal of the ossfied ligamenta flava improved her neurological dysfunction. The usefulness of the MRI in the neuroradiological diagnosis was confirmed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00339704
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  • 8
    Electronic Resource
    Electronic Resource
    Multiple sclerosis and corpus callosum atrophy: Relationship of MRI findings to clinical data (1988)
    Springer
    Neuroradiology 30 (1988), S. 478-480 
    Details
    ISSN: 1432-1920
    Keywords: Multiple sclerosis ; Magnetic resonance imaging ; Corpus callosum atrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Among 110 patients (45 men, 65 women), aged 15 to 66, with clinical and/or biological diagnosis of multiple sclerosis (MS), severe to moderate corpus callosum (CC) atrophy was observed in 67 (60%) patients. Correlation between CC atrophy, brain atrophy, duration and severity of clinical symptoms, and high signal white matter areas, was carried out in 90 patients. Mean age was 46 years for those with severe CC atrophy, and 33 years for those without atrophy. Mean duration of the disease was 14 years in patients with severe atrophy, and 5 years in patients without atrophy. Severity of clinical symptoms is more pronounced in patients with severe CC atrophy. Numerous or large white matter high signal areas are observed in patients with severe CC atrophy on T2-weighted images. CC atrophy appears earlier than brain atrophy in the course of MS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00339686
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  • 9
    Electronic Resource
    Electronic Resource
    Medullary lesion revealed by MRI in a case of MS with respiratory arrest (1988)
    Springer
    Neuroradiology 30 (1988), S. 574-576 
    Details
    ISSN: 1432-1920
    Keywords: Multiple sclerosis ; Respiratory arrest ; Magnetic resonance imaging ; Dual respiratory pathways
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 66-year-old MS patient who suffered respiratory arrest followed by complete remission is reported. Magnetic resonance imaging (MRI) revealed a medullary lesion. Clinicoradiological relationships are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00339705
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  • 10
    Electronic Resource
    Electronic Resource
    The MR appearance of hypothalamic hamartoma (1988)
    Springer
    Neuroradiology 30 (1988), S. 65-68 
    Details
    ISSN: 1432-1920
    Keywords: Hypothalamic hamartoma ; Precocious puberty ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Hypothalamic hamartoma is the most common detectable cerebral lesion causing precocious puberty. Two histologically confirmed cases were studied by computerized tomography (CT) and magnetic resonance (MR) imaging. T2 weighted, sagittal MR images were superior to CT in delineating the tumor from surrounding grey matter. The lesion was isointense to grey matter on T1 weighted images allowing exclusion of other hypothalamic tumors. MR will undoubtedly become the imaging modality of choice in the detection of hypothalamic hamartoma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341946
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  • 11
    Electronic Resource
    Electronic Resource
    Cavernous hemangioma of the thoracic spinal cord (1988)
    Springer
    Neuroradiology 30 (1988), S. 261-264 
    Details
    ISSN: 1432-1920
    Keywords: Cavernous hemangiorna ; Spinal cord ; Thoracic spine ; Computed tomography ; Metrizamide myelogram ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 25-year-old woman presented with a four-year history of progressive right-lower-extremity weakness and atrophy and a left hemisensory deficit was found. Metrizamide-enhanced spinal CT scan showed an intramedullary lesion at the level of T1-T2; this had expanded the cord in fusiform fashion but showed no evidence of a cystic component. Surgical resection was performed and the pathological diagnosis was cavernous hemangioma. Two and one-half years later, her left hemisensory deficit was worsening and a spinal MRI showed high signal intensity mass in the region of the previous surgery consistent with chronic hematoma which was re-evacuated with some improvement in the patient's neurological condition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341840
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  • 12
    Electronic Resource
    Electronic Resource
    MRI and CT of ankylosing spondylitis with vertebral scalloping (1988)
    Springer
    Neuroradiology 30 (1988), S. 272-275 
    Details
    ISSN: 1432-1920
    Keywords: Ankylosing spondylitis ; Cauda equina syndrome ; Vertebral scalloping ; Dural ectasia ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three cases of cauda equina syndrome in long-standing ankylosing spondylitis are reported. In all, vertebral scalloping and dural ectasia were confirmed by magnetic resonance imaging and computed tomography. MRI showed widening of the dural sac with signal intensity corresponding to cerebrospinal fluid. CT demonstrated asymmetrical lesions of the posterior elements of the lumbar spine. Myelography was not felt necessary to confirm the findings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341843
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  • 13
    Electronic Resource
    Electronic Resource
    MR imaging of intraspinal tumors—Capability in histological differentiation and compartmentalization of extramedullary tumors (1988)
    Springer
    Neuroradiology 30 (1988), S. 303-309 
    Details
    ISSN: 1432-1920
    Keywords: Magnetic resonance imaging ; Intraspinal tumor ; Meningioma ; Schwannoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Magnetic resonance (MR) images of 29 consecutive patients with intraspinal neoplasms (9 intramedullary tumors, 20 extramedullary tumors) were reviewed to evaluated the utility of MR imaging in distinguishing the intraspinal compartmental localisation and signal characteristics of each lesion. Compartment and histology of all neoplasms were surgically proven. MR correctly assigned one of three compartments to all lesions, 9 intramedullary, 14 intradural extramedullary (6 schwannomas, 3 neurofibromas, 5 meningiomas), and 6 extradural (3 schwannomas, 1 meningioma, 1 cavernous hemangioma, 1 metastatic renal cell carcinoma). All intramedullary tumors showed swelling of the spinal cord itself. In all five extradural tumors a low intensity band was visualized between the spinal cord and tumor. On the other hand, a low intensity band was demonstrated in no cases with intradural tumors. Visualization of this low intensity band is important in differentiating extradural from intradural-extramedullary lesions. We call this low intensity band, “the extradural sign”. Signal intensity of intradural tumors varied with histology. In extramedullary tumors, signal intensity of schwannomas was similar to that of the cerebrospinal fluid (CSF) both on T1 weighted (inversion recovery) and T2 weighted spin echo (SE) images. On the other hand, meningiomas tended to be isointense to the spinal cord on both T1 and T2 weighted SE images. We found relatively reliable signal characteristics to discriminate meningioma from schwannoma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00328180
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  • 14
    Electronic Resource
    Electronic Resource
    Magnetic resonance imaging in the evaluation of treatment in multiple sclerosis (1988)
    Springer
    Neuroradiology 30 (1988), S. 299-302 
    Details
    ISSN: 1432-1920
    Keywords: Magnetic resonance imaging ; Quantification ; Multiple sclerosis ; Treatment ; Evaluation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Magnetic resonance scans of 74 patients with multiple sclerosis participating in a controlled trial were compared 6 months before and at the end of a 24–32 months-treatment period with either Cyclosporin A (n=31) or Azathioprine (n=43). Both qualitative rating and computation of lesion volume showed deterioration in more than 40% of the patients, while by clinical criteria only 10–30% were worse. No significant difference was noted when the two treatment groups were compared. If careful repositioning and standardized image parameters are used, MRI is an indispensable tool for the objective determination of disease progression in MS although it cannot replace clinical examination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00328179
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  • 15
    Electronic Resource
    Electronic Resource
    Sodium-MR-imaging of the brain: initial clinical results (1988)
    Springer
    Neuroradiology 30 (1988), S. 399-407 
    Details
    ISSN: 1432-1920
    Keywords: Magnetic resonance imaging ; Sodium imaging ; Brain tumors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twelve patients with different diseases of the brain were examined with sodium and proton MRI at 1.5 Tesla and the results of both studies compared. Due to the 1500-fold lower concentration in the body, the decreased sensitivity and the shorter relaxation times of sodium compared with hydrogen a sequence with gradient reversal and a volume imaging method was applied to achieve a short echo time (4.5 ms). As a result of the mainly extracellular distribution of sodium the CSF spaces are depicted by their high signal intensity while the normal parenchyma is not visible. Changes induced by encephalitis, ischemic infarction and tumors can also be detected by their increased sodium content. Different tumors provided different signal intensities, not always permitting a distinction between tumor, surrounding edema and CSF. The diagnostic impact of these findings is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00404105
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  • 16
    Electronic Resource
    Electronic Resource
    MRI of intracerebral haematoma at low field (0.15T) using T2 dependent partial saturation sequences (1988)
    Springer
    Neuroradiology 30 (1988), S. 367-371 
    Details
    ISSN: 1432-1920
    Keywords: Magnetic resonance imaging ; Intracerebral haematoma ; Low field MRI
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Results of MRI at 0.15T in twelve successive patients with intracerebral haematoma are reviewed. Using T2 weighted spin echo (SE) and partial saturation (PS without a refocussing 180° pulse) sequences, low intensity areas were seen in eleven of the twelve cases. These included central regions (three cases), a peripheral rim (seven cases) and more diffuse patterns involving the brainstem and cerebral hemispheres (two cases). One case initially displayed a peripheral rim and later a central low intensity region. Central low intensity regions were seen in acute, subacute, and chronic cases. Follow up in five cases displayed an increase in signal within the haematoma in three cases and a decrease in signal intensity in two cases. Low signal intensity areas can be seen within and around intracerebral haematomas imaged with T2 weighted sequences at low field strength.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00404099
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  • 17
    Electronic Resource
    Electronic Resource
    Reversible brain shrinkage in abstinent alcoholics, measured by MRI (1988)
    Springer
    Neuroradiology 30 (1988), S. 385-389 
    Details
    ISSN: 1432-1920
    Keywords: Alcohol ; Magnetic resonance imaging ; Brain shrinking
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Magnetic resonance imaging of the intracranial CSF volume was compared before and after 5 weeks of confirmed abstinence in 9 alcohol-dependent patients. All patients showed a highly significant reduction in CSF volume in accordance with reexpansion of the brain after alcohol abstinence. T2 values for white matter, estimated by linear regression from 16 echoes of a CPGM sequence, however, showed no significant increase such as occurs in rehydration. This indicates, that alcohol-induced reversible brain atrophy cannot be attributed to fluctuation of free water in the brain only.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00404102
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  • 18
    Electronic Resource
    Electronic Resource
    Magnetic resonance imaging of cor triatriatum (1988)
    Springer
    Pediatric cardiology 9 (1988), S. 149-151 
    Details
    ISSN: 1432-1971
    Keywords: Cor triatriatum ; Magnetic resonance imaging ; Phase display
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Magnetic resonance imaging utilizing spin echo sequences was used to demonstrate cor triatriatum in an 18-year-old boy. Phase map images aided the diagnosis by demonstrating the presence of slowly flowing blood in the accessory atrial chamber. Magnetic resonance is an excellent modality for the noninvasive diagnosis of cor triatriatum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02080555
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  • 19
    Electronic Resource
    Electronic Resource
    Acquired cystic kidney disease in children undergoing long-term dialysis (1988)
    Springer
    Pediatric nephrology 2 (1988), S. 8-11 
    Details
    ISSN: 1432-198X
    Keywords: Acquired cystic kidney disease ; Magnetic resonance imaging ; Ultrasonography ; Children ; Peritoneal dialysis ; Hemodialysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Acquired cystic kidney disease (ACKD) occurs in adult patients undergoing long-term dialysis. Early detection is important because clinically significant hematuria and malignancies are associated with ACKD. We evaluated by magnetic resonance imaging (MRI) and ultrasonography (US) the incidence of ACKD in 15 patients aged 7.3–21.6 years (mean 15.9 years) with non-cystic primary renal disease. Nine patients had been treated with peritoneal dialysis only, and 6 with both hemodialysis and peritoneal dialysis for 24–73 months (mean 37 months). Three patients (20%) had no cysts. In 5 patients (33%) with bilateral multiple cysts, the diagnosis of ACKD was made by MRI and US. In another 5 patients, solitary cysts were localized to one kidney by MRI, and in 2 patients solitary cysts were seen in both kidneys. This study documents that ACKD is not limited to older patients with end-stage renal disease. Early detection of these cysts can be accomplished by MRI and is warranted since 1 patient developed neoplastic tubular changes which can precede tumor formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00870371
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  • 20
    Electronic Resource
    Electronic Resource
    Synchronous multicentric desmoid tumors (aggressive fibromatosis) of the extremities (1988)
    Springer
    Skeletal radiology 17 (1988), S. 16-19 
    Details
    ISSN: 1432-2161
    Keywords: Synchronous multicentric aggressive fibromatosis ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Synchronous multicentric aggressive fibromatosis does not appear to have been previously reported. Two such cases are described. The tumors were identified by magnetic resonance (MR) imaging. The incidence of synchronous multicentric aggressive fibromatosis is not known. It is anticipated that increased use of coronal MR imaging will reveal more tumors of this type, both synchronous and metachronous. In a patient with known or suspected aggressive fibromatosis, every other soft tissue nodule or mass in the same limb has to be regarded as an additional tumor of the same histology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00361449
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  • 21
    Electronic Resource
    Electronic Resource
    Magnetic resonance in cartilaginous lesions of the knee joint with three-dimensional gradient-echo imaging (1988)
    Springer
    Skeletal radiology 17 (1988), S. 465-471 
    Details
    ISSN: 1432-2161
    Keywords: Magnetic resonance imaging ; Threedimensional, gradient-echo sequence ; Chondromalacia ; Knee joint ; FLASH ; FISP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Diagnosis of chondromalacia of the patellofemoral joint using three-dimensional gradient-echo sequences was investigated in 41 patients, with arthroscopic verification in 25 patients. In vitro examinations in human caderveric patellae were performed in order to determine optimal imaging parameters. FLASH (TR=40 ms, TE=10 ms, flip angle=30°) and FISP (TR=40 ms, TE=10 ms, flip angle=40°) were used in clinical studies. Advanced stages of chrondromalacia could be visualized with high sensitivity. The therapeutically relevant differentiation of major and minor degrees of chondromalacia seems to be possible. 30° FLASH-images in the axial plane proved to be the most efficacious technique for the diagnosis of chondromalacia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00364038
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  • 22
    Electronic Resource
    Electronic Resource
    Magnetic resonance imaging of pyomyositis (1988)
    Springer
    Skeletal radiology 17 (1988), S. 190-193 
    Details
    ISSN: 1432-2161
    Keywords: Pyomyositis ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Pyomyositis is a relatively rare entity in temperate climates. Because of its rarity and its nonspecific clinical and radiographic findings, pyomyositis may be misdiagnosed and may cause severe morbidity and mortality. We present magnetic resonance imaging findings in two cases of pyomyositis. Magnetic resonance imaging was helpful in differentiating other pathological processes from pyomyositis, outlining the extent of involvement, and localizing the fluid collection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00351006
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  • 23
    Electronic Resource
    Electronic Resource
    Gadolinium-DTPA enhancement of soft tissue tumors in magnetic resonance imaging—preliminary clinical experience in five patients (1988)
    Springer
    Skeletal radiology 17 (1988), S. 319-323 
    Details
    ISSN: 1432-2161
    Keywords: Gadolinium-DTPA ; Magnetic resonance imaging ; Soft tissue tumor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a preliminary report of a clinical trial of gadolinium-DTPA (Gd-DTPA) for enhancement of soft tissue tumors in magnetic resonance imaging (MRI), experience of the first five cases is presented. Enhancement was found to give better delineation of the tumor in richly vascularized parts of the tumors, compressed tissue immediately surrounding the tumor, and in atrophic, but richly vascularized, muscle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00367175
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  • 24
    Electronic Resource
    Electronic Resource
    Cardiac tumour in a neonate with tuberous sclerosis: echocardiographic demonstration and magnetic resonance imaging (1988)
    Springer
    European journal of pediatrics 148 (1988), S. 50-52 
    Details
    ISSN: 1432-1076
    Keywords: Tuberous sclerosis ; Echocardiography ; Magnetic resonance imaging ; Neonate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a neonate with tuberous sclerosis, cardiac tumours were diagnosed by two-dimensional echocardiography and evaluated by electrocardiogram-gated magnetic resonance imaging (MRI). The tumour size, shape and mobility in the ventricular cavities were more precisely determined by two-dimensional echocardiography than electrocardiogramgated MRI, while the extent of tumour mass at the apex was more clearly delineated by MRI. As two-dimensional echocardiography provides real-time imaging of cardiac anatomy without sedation, it is useful for initial evaluation of cardiac masses in neonates with genetic predisposition to tuberous sclerosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00441814
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  • 25
    Electronic Resource
    Electronic Resource
    Structural brain correlates of anterograde memory deficits in multiple sclerosis (1988)
    Springer
    Journal of neurology 235 (1988), S. 362-365 
    Details
    ISSN: 1432-1459
    Keywords: Multiple sclerosis ; Neuropsychology ; Memory functions ; Dementia ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Progressive decline of anterograde memory functions has been increasingly recognized as a frequent symptom in chronic multiple sclerosis. In order to investigate the brain structures involved, magnetic resonance imaging was performed in 20 patients. Neuropsychological assessment included the WAIS and WMS subtests information, picture completion, similarities, digit span, logical memory, and paired associate learning. All patients with severely impaired memory functions (n=5) showed bilateral lesions in the medial temporal lobe, whereas in those patients with moderate (n=10) or no measurable impairment of memory testing (n=5) either no lesions were seen in the medial temporal lobes or these lesions were restricted to one side. A post hoc cluster analysis strikingly confirmed these results. The differences could not be related to the age of the patients, the disease duration, or the level of education. Extensive lesions in the white matter of the frontal lobes, thinning and lining of the corpus callosum, and bilateral involvement of the anterior cingulate gyrus had no bearing on the neuropsychological results. These findings indicate that bilateral demyelination in the hippocampal regions is the most likely explanation for the impairment of anterograde memory in such patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00314234
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  • 26
    Electronic Resource
    Electronic Resource
    Intravenous natural beta interferon treatment of chronic exacerbating-remitting multiple sclerosis: clinical response and MRI/CSF findings (1988)
    Springer
    Journal of neurology 235 (1988), S. 171-173 
    Details
    ISSN: 1432-1459
    Keywords: Multiple sclerosis ; Interferon ; Cerebrospinal fluid ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A preliminary study is reported of clinical response and CSF/MRI findings in nine patients with multiple sclerosis receiving intravenous infusions of natural beta-interferon. The mean patient follow-up was for 1.2 years. Neither exacerbation rates nor CSF-IgG synthesis nor plaque formation as revealed by MRI showed a significant reduction during therapy. One patient developed a severe exacerbation of multiple sclerosis shortly after interferon infusion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00314311
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  • 27
    Electronic Resource
    Electronic Resource
    Magnetic resonance imaging of dysraphic myelodysplasia (1988)
    Springer
    Child's nervous system 4 (1988), S. 149-153 
    Details
    ISSN: 1433-0350
    Keywords: Magnetic resonance imaging ; Postrepair meningomyelocele ; Dysraphic myelodysplasia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The spinal cord in 56 children and adolescents was examined by magnetic resonance imaging (MRI) many years after neonatal surgery on a meningomyelocele (average age 12 years). In a high percentage of cases, the diagnosis “tethered cord” was made. Associated anomalies were found with a frequency of 21%. Typical findings are presented and the impact of these results on therapy planning is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00270906
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  • 28
    Electronic Resource
    Electronic Resource
    Magnetic resonance images of chronic patellar tendinitis (1988)
    Springer
    Skeletal radiology 17 (1988), S. 24-28 
    Details
    ISSN: 1432-2161
    Keywords: Magnetic resonance imaging ; Chronic patellar tendinitis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Chronic patellar tendinitis can be a frustrating diagnostic and therapeutic problem. This report evaluates seven tendons in five patients with chronic patellar tendinitis. The etiologies included “jumper's knee” and Osgood-Schlatter disease. In all cases magnetic resonance images (MRI) showed thickening of the tendon. Some of the tendons had focal areas of thickening which helped establish the etiology. All cases had intratendinous areas of increased signal which, in four cases, proved to be chronic tendon tears. MRI is useful in evaluating chronic patellar tendinitis because it establishes the diagnosis, detects associated chronic tears, and may help determine appropriate rehabilitation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00361451
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  • 29
    Electronic Resource
    Electronic Resource
    The impact of magnetic resonance on the diagnostic evaluation of acute cervicothoracic spinal trauma (1988)
    Springer
    Skeletal radiology 17 (1988), S. 89-95 
    Details
    ISSN: 1432-2161
    Keywords: Magnetic resonance imaging ; Trauma ; Spine ; Cervicothoracic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract From 1984 to 1987 magnetic resonance (MR) imaging was performed on 100 patients suffering acute spinal trauma. MR demonstrated one or more injuries to the cervicothoracic region in 31 patients. It displayed a spectrum of spinal cord injury ranging from mild compression and swelling to complete transection. MR was also useful in evaluating alignment at the cervicothoracic junction, in depicting ligamentous injury, in establishing the presence of disc herniation, and in identifying unsuspected levels of injury. We present a diagnostic algorithm that incorporates the role of MR in evaluating acute cervicothoracic spinal trauma and emphasizes the replacement of myelography by MR in the initial assessment of neurologic deficit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00365133
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  • 30
    Electronic Resource
    Electronic Resource
    Computer tomography and magnetic resonance imaging in cvanide poisoning (1988)
    Springer
    European archives of psychiatry and clinical neuroscience 237 (1988), S. 139-143 
    Details
    ISSN: 1433-8491
    Keywords: Cyanide poisoning ; Basal ganglia ; Computerized tomography ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 29-year-old chemistry student took 50 ml of a 1% potassium cyanide solution (500 mg) in an attempted suicide. He became comatose, mydriatic, and was admitted to hospital in an apneic state. He woke up after 7 h and developed Parkinsonism in the following weeks. This regressed slowly during the 2 months after the poisoning apart from dysarthria, bradykinesia of the upper limbs, and very brisk monosynaptic reflexes. At 3 weeks after the intoxication, computerized tomography was largely normal, and there was CSF-dense hypodensity in both putamina after 5 months. Sharply delimited signal elevation in T2 corresponding to the two putamina was detected by magnetic resonance imaging 8 weeks and 5 months after ingestion of the poison.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00451281
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  • 31
    Electronic Resource
    Electronic Resource
    Cerebellar ataxia with recovery related to central pontine myelinolysis (1988)
    Springer
    Journal of neurology 235 (1988), S. 379-381 
    Details
    ISSN: 1432-1459
    Keywords: Central pontine myelinolysis ; Cerebellar ataxia ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Development of severe ataxia and mild pyramidal signs without mental deterioration, tetraparesis or pseudobulbar palsy during recovery from withdrawal delirium and initial hyponatraemia are unusual clinical features consistent with central pontine myelinolysis. This diagnosis was confirmed by magnetic resonance imaging (MRI) in an alcoholic man. Clinical and electrodiagnostic improvement occurred, whereas the MRI findings remained unchanged in a follow-up study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00314240
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  • 32
    Electronic Resource
    Electronic Resource
    Lymphomatoid granulomatosis: clinical and histopathological report of a patient presenting with spinal cord involvement (1988)
    Springer
    Journal of neurology 235 (1988), S. 432-434 
    Details
    ISSN: 1432-1459
    Keywords: Lymphomatoid granulomatosis ; Spinal cord syndrome ; Magnetic resonance imaging ; Histopathology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An unusual mode of presentation of lymphomatoid granulomatosis is reported. A 19-year-old man developed spinal cord symptoms, and magnetic resonance imaging of the spinal cord disclosed a compatible lesion. Despite medical therapy the outcome was fatal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00314489
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  • 33
    Electronic Resource
    Electronic Resource
    MRI appearances of the CNS manifestations of Mycoplasma pneumoniae: a report of two cases (1988)
    Springer
    Journal of neurology 235 (1988), S. 441-443 
    Details
    ISSN: 1432-1459
    Keywords: Mycoplasma pneumoniae ; Encephalomyelitis ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two patients are reported with Mycoplasma pneumoniae-related cervical myelitis. Magnetic resonance imaging in each case demonstrated clinically silent lesions suggesting more extensive neurological involvement. This supports the concept of widespread immunologically mediated disease occurring as a remote effect of initial M. pneumoniae respiratory infection. Differences from the MRI appearances of a patient with mycoplasma-related Guillian-Barré syndrome imply that more than one antigenic determinant is involved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00314492
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  • 34
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    Electronic Resource
    Influence of magnetic resonance imaging on somatosensory and brain-stem auditory evoked potentials in man (1988)
    Springer
    Journal of neurology 235 (1988), S. 462-465 
    Details
    ISSN: 1432-1459
    Keywords: Evoked potentials ; Magnetic resonance imaging ; Somatosensory evoked potentials ; Brain-stem auditory evoked potentials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary There is still a need to prove that even static magnetic fields up to 1.5 T used in magnetic resonance imaging (MRI) are biologically safe and harmless for humans. Recordings of median and ulnar nerves and brain-stem auditory evoked potentials in 20 patients were completed prior to and after MRI investigation of the central nervous system. Neither the somatosensory nor the auditory evoked potentials exhibited any significant change of latencies, interpeak latencies or amplitudes. Since these electrophysiological parameters are highly dependent on the quality of nerve conduction and integrity of information processing in various nuclei, it may be assumed that MRI causes no lasting changes in either respect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00314248
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  • 35
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    Electronic Resource
    Magnetic resonance imaging of the brain and spine (1988)
    Springer
    Journal of neurology 235 (1988), S. 193-206 
    Details
    ISSN: 1432-1459
    Keywords: Magnetic resonance imaging ; Comparative studies ; Central nervous system ; Brain diseases ; Spine diseases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The efficacy of magnetic resonance imaging (MRI) in the diagnosis of diseases of the central nervous system is reviewed. MRI, computed tomography (CT) and certain radionuclide studies are compared in the evaluation of intracranial tumours, cerebral vascular disease, multiple sclerosis and other white matter diseases, dementia, head injury, infection, epilepsy, spinal lesions and in paediatric central nervous system disorders. The measurement of cerebrospinal fluid volumes and dynamics by MRI is discussed. MRI most clearly has advantages where CT is degraded by bone hardening and streak artefacts (spine, skull base, posterior and temporal fossa, sella and parasellar regions) and in diseases in which the X-ray attenuation of the suspected lesion differs little from normal parenchyma (paediatric brain disorders, demyelination and dysmyelination, early oedema associated with infarction, infection or low-grade infiltrating neoplasm, subacute and chronic haemorrhage and lesions in the spinal subarachnoid space and cord). Elsewhere MRI and CT should be seen as complementary rather than competitive methods of imaging. In spite of an absence of information about the contribution of MRI to management decisions and a lack of rigorous, prospective controlled trials, MRI will play an increasing role in the diagnosis of diseases of the central nervous system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00314347
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  • 36
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    Electronic Resource
    The application of magnetic resonance imaging in maxillo-facial region: A comparison with CT (1988)
    Springer
    Oral radiology 4 (1988), S. 1-6 
    Details
    ISSN: 1613-9674
    Keywords: Magnetic resonance imaging ; Computed tomography ; Maxillo-facial region
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Magnetic resonance imaging (MRI) studies were obtained in 49 cases of various diseases in the maxillo-facial region and the results compared with X-ray computed tomography (CT). Bot MRI and CT scans were performed in 44 cases. In 31 cases (70%), MRI provided similar or superior information to that of CT in the evaluation of various diseases. In 10 cases, MRI was superior to CT in defining the images of diseases, 7 cases of these were carcinomas. CT was superior to MRI in 5 cases, especially in demonstrating calcifications and bony changes. Artifacts caused by prosthetic metals and patient motion disturbed MR images. Our experience with MRI lead us the conclusion that it holds great potential and that it already had some advantages over CT in the maxillo-facial region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02348643
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  • 37
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    Electronic Resource
    Dynamic MR imaging of the temporomandibular joint and the related structures using 0.5 T unit: The normal study (1988)
    Springer
    Oral radiology 4 (1988), S. 17-21 
    Details
    ISSN: 1613-9674
    Keywords: Joints ; Temporomandibular joints ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Gradient-field-echo technique was employed to evaluate the movement of the temporomandibular joint meniscus and the related structures combined with the opening of the mouth for asymptomatic TM joints in the use of a 0.5 T super-conductive MR system. The examination for the mouth opening phase took less than one minute. The movement of the meniscus was clearly presented especially by using a cine-mode display. The signal intensity in the retro-meniscus and the lateral pterygoid muscle was increased by the opening. These findings indicate that the MR dynamic imaging may be promising in diagnosing not only the shape of the meniscus but also the function of the TM joint.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02348953
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  • 38
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    Electronic Resource
    Nuclear magnetic resonance imaging of the heart (1988)
    Springer
    European journal of nuclear medicine 13 (1988), S. 653-660 
    Details
    ISSN: 1619-7089
    Keywords: Magnetic resonance imaging ; Cardiac imaging ; Cardiac function ; Fast NMR imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract NMR imaging is a noninvasive technique that has been shown to provide high-quality images of the heart. Due to the signal characteristics of flowing blood, inherent contrast between blood pool and myocardium is achieved without the use of contrast media. This paper briefly describes technical aspects of NMR imaging of the heart, normal cardiovascular anatomy, applications of the technique in patients with ischemic heart disease, and the potential of NMR imaging for functional studies in various forms of heart disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00256393
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  • 39
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    Electronic Resource
    Rapid quantification of 11 prostanoids by combined capillary column gas chromatography and negative ion chemical ionization mass spectrometry: Application to prostanoids released from normal human embryonic lung fibroblasts WI38 in a culture medium (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 25-32 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rapid and simultaneous quantification of 11 prostanoids has been carried out with a short-capillary gas chromatograph and negative ion chemical ionization (ammonia) mass spectrometer.The methoxime-trimethylsilyl ether-pentafluorobenzyl esters (MO-TMS-PFB) of nine prostanoids, PGA1, PGA2, PGB1, PGB2, PGD2, PGE1, PGE2, 6-oxo-PGF1α and TXB2 and the TMS-PFB of two prostanoids, PGF1α and PGF2α, were separated in less than 5.5 min on a bonded OV-1 capillary column 0.25 mm i.d. × 6 m (0.15 μm thickness) using hydrogen as a carrier gas. PGD2, PGE2, PGF2α, 6-oxo-PGF1α and TXB2 were quantified up to 2.5 fmol injected (0.1 pmol derivatized) and both PGA2 and PGB2 up to 25 fmol injected (1 pmol derivatized).In order to maintain the stability of the prostanoids containing a carbonyl group, such as TXB2 during the purification and derivatization steps of biological materials, methyl acetate was used in place of methyl formate as an eluant for Sep-Pak C18 purification.Normal human embryonic lung fibroblasts W138 (5.63 × 105 cells in a log phase) produced: PGA2 15.28, PGB2 13.48, PGD2 7.95, PGE1 2.62, PGE2 177.76, PGF2α 25.14, 6-oxo-PGF1α 27.33 and TXB2 61.00 pmol in 10 ml of Eagle minimal essential medium.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150105
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  • 40
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    Measurement of urinary lactic, 3-hydroxybutyric, pyruvic and acetoacetic acids in a single analysis using selected ion monitoring and stable isotope labelling techniques (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 57-62 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Sodium borodeuteride treatment of urine expected to have large concentrations of pyruvic and acetoacetic acids produces lactic and 3-hydroxybutyric acids labelled with deuterium. Mass fragmentographic techniques applied to the trimethylsilyated extract of the urine spiked with more extensively labelled analogues as internal standards permit the reliable determination of lactic, pyruvic, 3-hydroxybutyric and acetoacetic acids in a single analysis.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150108
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  • 41
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    Electronic Resource
    Characterization of trichothecenes by ammonia chemical ionization and tandem mass spectrometry (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 79-87 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ammonia and deuterated ammonia chemical ionization (CI) mass spectra and collisionally activated dissociation (CAD) mass spectra of ammonium adduct ions are presented for ten trichothecenes. The samples were introduced by direct exposure probe. Effects of ion source temperature and pressure on the ammonia CI gas plasma and the formation of the ammonium adduct ion were studied. The CI conditions were optimized to produce a maximal yield for the ammonium adduct ion of trichothecenes, i.e. the parent ion for tandem mass spectral analysis. Besides source temperature and pressure, proton affinity and the stability of the ammonium adduct ion affect the relative abundance ratio of [M + H]+:[M + NH4]+ in ammonia CI and CAD mass spectra. The ratio [M + H]+:[M + NH4]+, and hence the stability of the ammonium adduct ion, are largely determined by the functional groups (hydroxy, carbonyl, acetoxy, and isovaleroyloxy) and their location in the trichothecene nucleus. The most abundant fragment ions in the ammonia CI spectra and the most abundant daughter ions in the CAD spectra of the ammonium adduct ions are formed by the losses of ammonia and functional groups as neutrals in various combinations.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150205
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  • 42
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    The application of gas chromatographic/mass spectrometric techniques to spin trapping. Conversion of α-phenyl N-tert-butyl nitrone (PBN) spin adducts to stable trimethylsilylated derivatives (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 111-116 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of an aminoxyl and the corresponding hydroxylamine with silylating agents is studied in detail. The gas chromatographic/mass spectrometric analysis of the products is consistent with the production of an unsaturated product when an alkyl group with exchangeable hydrogens is attached to the nitrone group. The structure of this compound is confirmed by deuteration. It is concluded that aminoxyls themselves do not derivatize wth silylating agents.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150209
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  • 43
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    Gas chromatography/mass spectrometry and gas chromatography/tandem mass spectrometry of methyl ester/methoxime/trimethylsilyl ether derivatives of prostaglandins (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 129-138 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electron impact mass spectra of methyl ester/trimethylsilyl ether derivatives of prostaglandin F2α and methyl ester/methoxime/trimethylsilyl ether derivatives of prostaglandin E2, prostaglandin D2, 6-oxo-prostaglandin F1α and 2,3-dinor-6-oxo-prostaglandin F1α are presented. Most of the prostaglandins studied have additionally been 2H-labelled at different sites in order to assign the corresponding fragment ions. Collisionally activated decomposition mass spectra of the most intense parent ions in the high-mass region were taken. High-intensity, prostaglandin-characteristic daughter fragments will allow a reliable quantification of prostaglandins in biological fluids and a reduction of sample clean-up.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150303
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  • 44
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    A gas chromatographic/mass spectrometric assay for catechol estrogens in microsomal incubations: Comparison with a radiometric assay (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 157-161 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A gas chromatographic/mass spectrometric assay for quantifying two catechol estrogens, 2-hydroxyestradiol and 4-hydroxyestradiol, in microsomal preparations is described. The assay employs deuterium-labeled analogs of the catechol estrogens as internal standards and permits quantification of catechol estrogens, in microsomal incubations, at low (1-2) μM concentrations. The compounds are analyzed as their trimethylsilyl derivatives following separation by capillary gas chromatography.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150307
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  • 45
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    Electronic Resource
    Electron capture negative ion chemical ionization analysis of arachidonic acid (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 175-178 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A highly sensitive (subpicomole level) and structural specific method for the analysis of arachidonic acid esterified to complex glycerophospholipids has been developed using combined capillary gas chromatography and mass spectrometry. The methodology is based upon the formation of the pentafluorobenzyl ester of arachidonic acid, which is efficiently ionized using electron capture negative ion chemical ionization conditions to yield an abundant carboxylate anion at m/z 301. Quantification is carried out following hydrolysis of the complex glycerophospholipid in the presence of a known amount of (2H8) araachidonic acid. The use of this method is illustrated by the quantification of arachidonic acid within the glycerophospholipid classes isolated from resident peritoneal macrophage cells isolated from HS mice.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150309
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  • 46
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    Mass spectral investigations on trichothecene mycotoxins. V. Direct analysis of satratoxins by tandem mass spectrometric techniques (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 185-191 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Under chemical ionization conditions, satratoxins preferentially produce negatively charged molecular ions (M-·) over the positively charged protonated molecules. Collisionally activated dissociation of the M-· ions resulted in daughter ions and neutral losses which were characteristic of the macrocyclic ester bridges. Direct tandem mass spectrometric methods of analyses wee developed and applied for the detection and quantification of satratoxins in Stachybotrys atra fermentation broths. Minimum detectable levels for satratoxin standards were 5 pg. A synthetically modified macrocyclic trichothecene, 8-ketoverrucarin A, was used as an internal standard for the quantification of satratoxins in fermentation samples.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150402
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  • 47
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    Thermospray liquid chromatography tandem mass spectrometry: Application to the elucidation of zolpidem metabolismThis work was presented in part at the 4th Symposium on Liquid Chromatography/Mass Spectrometry and Mass Spectrometry/Mass Spectrometry, Montreux (Switzerland), October 22-24, 1986. (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 223-228 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This paper discusses the possible advantages of thermospray liquid chromatography/tandem mass spectrometry LC/MS/MS for metabolic mapping. The technique was applied to the study of the metabolism of zolpidem, a new hypnotic with an imidazo-pyridine moiety. When compared to other chromatographic/mass spectrometric-based techniques, reversed phase high-performance liquid chromatography coupled with thermospray LC/MS/MS appears to be the fastest method available today for elucidation of unknown metabolic structures, since it allows identification by direct injection of concentrated urine. However, it was noted during the thermospray process that loss of formaldehyde from a hydroxymethyl amide metabolite occurred. This degradation was not observed when this metabolite was analysed by gas chromatography/mass spectrometry following trimethylsilylation.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150406
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  • 48
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    Fast atom bombardment mass spectrometry of high-molecular-weight fraction of porphyrin-based photodynamic therapy drugs (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 257-263 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photodynamic therapy (PDT) involves the treatment of tumor tissue with a photosensitizer and light to effect the delineation and/or eradication of the tumor. PDT is a two step process: (1) incorporation of photosensitizer into the cell where it must be retained by tumors in vivo; and (2) illumination of the tumor cell with light to effect cell death. Hematoporphyrin derivative (HPD) is a complex mixture of porphyrins currently used for PDT in the clinical setting. Hematoporphyrin-based oligomers of up to five subunits were determined using fast atom bombardment mass spectrometry of the high-molecular-weight fraction of the drug. Reduction of this fraction with LiAlH4 permitted determination of the covalent bond linking the monomers in these oligoporphyrins. Application of these analytical procedures to the determination of the composition of different preparations of HPD will be described.
    Additional Material: 3 Ill.
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    (18O)quinolinic acid: Its esterification without back exchange for use as internal standard in the quantification of brain and CSF quinolinic acid (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 291-293 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the process of developing a high-sensitivity negative chemical ionization gas chromatographic/mass spectrometric assay for brain and cerebrospinal fluid (CSF) levels of quinolinic acid (QUIN, 2,3-pyridine dicarboxylic acid), (18O4)QUIN was prepared. Its properties as an internal standard were compared with those of the structural isomer 2,4-pyridine decarboxylic acid (2,4-PDC) previously used by others. All oxygen atoms in QUIN were labeled by heating in 3N HCl/(18O)water for 48 h at 80°C. Back-exchange of (18O4)QUIN was prevented during derivatization to an electron-capturing dihexafluoropropanol ester by using trifluoroacetylimidazole as catalyst instead of perfluroacyl anhydrides. When mixtures of QUIN and (18O4)QUIN and/or 2,4-PDC were followed through a procedure to isolate and quantify brain and CSF QUIN, the variability in the ratio of QUIN:2,4-PDC was greater than for QUIN:(18O)QUIN. We conclude that (18O)QUIN is the preferred internal standard in gas chromatographic/mass spectrometric quantification of brain and CSF QUIN, and that (18O)-labeled carboxylic acids may be esterified effectively without back-exchange using acylimidazole reagents.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150509
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  • 50
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    Electronic Resource
    252CF plasma desorption mass spectrometry of a polycyclic peptide antibiotic, Nisin (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 305-310 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polycyclic peptide antibiotic, Nisin, has been analysed by plasma desorption mass spectrometry using two different sample preparation techniques and two versions of the commercial plasma desorption mass spectrometer, and a prototype with high resolving power. The spectra obtained allow identification of a major component and two minor analogues. Extensive fragmentation is observed in samples prepared by the electrospray technique, whereas only ions indicating the molecular weight are produced when the sample is adsorbed on nitrocellulose.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150602
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    Gas chromatography/mass spectrometry and gas chromatography/mass spectrometry/mass spectrometry of methyl ester/methoxime/trimethylsilyl ether derivatives of thromboxanes (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 139-142 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electron impact mass spectra of methyl ester/methoxime/trimethylsilyl ether derivatives of thromboxane B2 (TxB2) and 2,3-dinor-TxB2 and methyl ester/trimethylsilyl ether derivative of 11-dehydro-TxB2 are presented. Additionally, the derivatives of (2H4)-thromboxanes and methyl ester (2H3)-methoxime/trimethylsilyl ether derivatives of TxB2 and 2,3-dinor-TxB2 and (2H3)-methyl ester/trimethylsilyl ether derivative of 11-dehydro-TxB2 were investigated. Collision-induced dissociation mass spectra of the most intense parent ion in the high-mass region were taken. Collisionally activated decomposition mass spectra of the [C(12)-C(20)]+ ion of TxB2 and 2,3-dinor-TxB2 show an intense but not specific daughter ion, whereas the collison-induced dissociation mass spectrum of the [M - (C(16)-C(20)]+ ion of 11-dehydro-TxB2 results in the formation of numerous daughter ions.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150304
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    Collisional spectroscopy as a screening procedure for the determination of 2-(2-furoyl)-4(5)-(2-furanyl)-1H-imidazole from acid hydrolysis of B-poly(L-Lysine) and B-albumin (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 7-11 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The direct determination of 2-(2-furoyl)-4(5)-(2-furanyl)-1H-imidazole (FFI), present in the acid hydrolysis products of B-poly(L-lysine) and B-albumin and which appears to be a key intermediate in the physicochemical changes occurring during the incubation of protein with glucose, has been carried out by collisional spectroscopy, using a commercial double-focusing, reverse-geometry mass spectrometer and without any sample derivatization and chromatographic separation procedures.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150103
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    A gas chromatographic/mass spectrometric screening, confirmation, and quantification method for estrogenic compounds (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 45-56 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method is described for the screening, quantification and confirmation of a variety of estronenic substances in animal tissues. A solid-phase extraction technique combined with a liquid/liquid extraction allows for rapid sample preparation and high throughput for the following compounds in bovine liver, muscle and kidney: diethylstilbestrol, dienestrol, hexestrol, zeranol, taleranol, zearalanone, zearalenone, zearalenol, estradiol and estriol. Gas chromatography/mass spectrometry and selected ion monitoring is used for the determination with detection limits ranging from 50 to 150 ppt.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150107
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    Packed column supercritical fluid chromatography/mass spectrometry using a thermospray source in the filament-on mode (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 105-109 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Combined packed column supercritical fluid chromatography/mass spectrometry has been effected using a thermospray ion source in the filament-on mode. If organic modifiers are used with carbon dioxide as the supercritical mobile phase, chemical ionization mass spectra are obtained. With carbon dioxide electron impact type mass spectra are obtained. The potential of the system is illustrated with studies of mixtures of carbamate and organochlorine pesticides and a crude ergot fermentation extract.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150208
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  • 55
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    The identification of biologically important thiols (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 123-128 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new mass spectral method has been developed and used to identify biologically important thiols. This method is based upon the use of C-14 labeled N-para-bromophenylmaleimide (BPM) to selectively derivatize thiols. The isotopic label facilitates the isolation and purification of trace quantities of the maleimide thiol adducts by high performance liquid chromatography (HPLC) with radioactivity detection. The use of the bromine atom in the thiol derivative greatly enhances the detectability of the parent and fragment ions containing the BPM moiety because of the generation of the characteristic N + 2 doublet ions. Several examples of the use of this method to identify non-volatile thiol peptides such as glutathione (GSH) and homoglutathione (hGSH) by fast atom bombardment mass spectrometry (FAB-MS) are described in this report.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150302
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    In vivo metabolism of (+)-trans-Delta-9-tetrahydrocannabinol in the mouse (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 117-122 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (+)-trans-Delta-9-tetrahydrocannabinol [(+)-delta-9-THC], a biologically inactive isomer of (-)-trans-delta-9-THC, the major psychoactive constituent of cannabis, was administered intraperitoneally to male Charles River CD-1 mice; hepatic metabolites were extracted with ethyl acetate and isolated by chromatography on Sephadex LH-20 in chloroform. The metabolites were converted into trimethylsilyl (TMS), 2H9-TMS and methyl ester/TMS derivatives for examination by gas chromatography/mass spectrometry and additional samples were prepared by reduction of metabolic fractions with lithium aluminium deuteride. Sixteen metabolites were characterized: these were alcohols and carboxylic acids, together with several of their hydroxylated analogues. The major biotransformation pathway was hydroxylation at C(11) to give the major metabolite, followed by oxidation of this compound to a carboxylic acid. Hydroxylated analogues of these two compounds were substituted mainly in the side-chain. Although metabolism was very similar to that of the naturally occurring (-)-isomer as far as positions of substitution were concerned, some differences were observed. These related mainly to the positions of hydroxylation on the side-chain, where 1′-hydroxylation was preferred to hydroxylation at the 2′-position. The major difference in metabolism between the two isomers was that much less oxidation of the 11-hydroxy group to a carboxylic acid occurred and there was less hydroxylation at the 8-position. Thus, 11-hydroxy-(+)-trans-delta-9-THC was the major metabolite and most other metabolites were hydroxylated derivatives of this compound.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150210
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    Negative ion chemical ionization gas chromatography/mass spectrometry and gas chromatography/tandem mass spectrometry of prostanoid pentafluorobenzyl ester/methoxime/trimethylsilyl ether derivatives (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 143-151 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Negative ion chemical ionization mass spectra of prostaglandin F2α, prostaglandin E2, prostaglandin D2, 6-oxo-prostaglandin F1α, 2,3-dinor-6-oxo-prostaglandin F1α, thromboxane B2, 2,3-dinor-thromboxane B2, and 11-dehydro-thromboxane B2 pentafluorobenzyl ester (PFB)/methoxime/trimethylsilyl ether derivatives are presented. Collisionally activated decomposition mass spectra of the [M - PFB]- ions at collision energies of 8-24 eV and argon collision gas pressures of 1-2 mTorr almost show only fragmentation of trimethylsilanol, (CH3)2Si=CHOH, (CH3)2Si=CH2 and methanol whereas, except for carbon dioxide loss, only few low-intensity fragments from the carbon skeleton of the prostanoids are observed.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150305
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    Continuous flow fast atom bombardment liquid chromatography/mass spectrometry: Studies involving conventional bore liquid chromatography with simultaneous ultraviolet detection (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 179-182 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A conventional bore liquid chromatograph has been interfaced to quadrupole and magnetic sector mass spectrometers configured for fast atom bombardment ionization via a continuous flow FAB probe. It is shown that post-column addition of FAB matrix and in-line ultraviolet detection facilities do not significantly compromise chromatographic integrity and that high quality mass spectra are obtainable from such FAB LC/MS studies.
    Additional Material: 6 Ill.
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    Rapid identification of drug metabolites with tandem mass spectrometry (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 193-204 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method which involves the use of tandem mass spectrometry (MS/MS) for the identification of drug metabolites has been demonstrated with a triple quadrupole mass spectrometer. The method is based on the fact that metabolites usually retain various substructures of the original drug molecule. MS/MS is capable of rapidly identifying molecules with characteristic substructures without prior separation. It is shown that this method makes it possible to postulate possible drug metabolite structures rapidly and systematically without the use of standards. The MS/MS method, as it was applied to the identification of the metabolites of a new antiepileptic drug, zonisamide, is discussed. In this case it was possible to identify isomeric metabolites due to their differences in vaporization times off the probe and their different daughter spectra. The complementary uses of the neutral loss and parent scans for the determination of the site of metabolism is demonstrated. A new figure of merit, the limit of identification, is introduced. The amount of the epoxide metabolite of carbamazepine necessary for its reliable identification in urine was shown to be 0.4 ng/μl. The application of various techniques to confirm preliminary findings with this MS/MS method are described.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150403
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    Masthead (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988) 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150101
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    Mass spectral investigations on trichothecene mycotoxins IV - collisionally activated dissociation mass spectra (negative ion) of some macrocyclic trichothecenes (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 13-24 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Macrocyclic trichothecenes are di- and triesters of simple trichothecenes such as verrucarol and oxygenated verrucarols. They form the negatively charged molecular (M-·) ions more effectively than the positively charged protonated molecules under chemical ionization (methane) conditions. This is proposed to be due to extended conjugation at the macrocyclic ester bridges of the molecules. The M-· ions of several macrocyclic trichothecenes undergo collisionally activated dissociation (argon) yielding the daughter ions characteristic of the ester bridges. Structures for various specific and abundant ions observed in the tandem mass spectra are proposed. The daughter ions and experimental conditions for the specific detection of these trichothecenes are selected. A semi-synthetic macrocyclic trichothecene is found to be an adequate internal standard for the analysis of macrocyclic trichothecenes under collisionally activated dissociation (CAD) conditions. Low nanogram (1-2) quantities of roridin H and satratoxins are detected under these conditions. Preliminary results indicate the applicability of this negative ion chemical ionization/tandem mass spectrometric method for the analysis of macrocyclic trichothecenes in real samples.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150104
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    Masthead (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988) 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150201
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    Evaluation of the quantitative analysis of a steroid sulphate using fast atom bombardment and tandem mass spectrometry (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 99-104 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dehydroepiandrosterone sulphate (DHAS) has been quantified in human blood serum by fast atom bombardment (FAB)/tandem mass spectrometry of immunoadsorption extracts. FAB of DHAS yielded abundant ions corresponding to the intact steroid sulphate; these were selected by a double-focusing mass spectrometer prior to collisionally activated decomposition in a quadrupole collision cell and mass analysis by a quadrupole mass filter. [HSO4]- (m/z 97) was the sole prominent daughter ion. For quantitative analyses the quadrupole mass filter was set to transmit m/z 97 and a narrow-range magnet scan yielded a spectrum of parents, including m/z 367 and 369, corresponding to DHAS and the (2H2)-analogue (used as internal standard), respectively. Serum concentrations by this procedure were in good agreement with data obtained by gas chromatographic/mass spectrometric analyses of DHA heptafluorobutyrate, formed by direct derivatization of the steroid sulphate.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150207
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    Determination of sodium salts of monensins A and B in the premix and the fermentation broth by electron impact mass spectrometry (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 153-156 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electron impact mass spectrometry has been used to determine the ratio of monensin A and B, and monensin A with monensin B as an internal standard in extracts of the premix and the fermentation broth. From the data obtained the total amount of monensin A and B was calculated and compared with the results of photometric determination. The relative width of the confidence intervals for the determination of monensin A and B ratio was 2% (2%) in the premix (fermentation broth), 5% (7%) for monensin A, 13% (14%) for monensin B and 5% (6%) for the total amount of monensins A and B. The limit of determination of monensins was about 100 ng. The difference in the results of photometric and mass spectrometric determination was significant for fermentation broth. No significant difference was found in the premix.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150306
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    A mass spectral study of cyclophosphamide concerning a thermally induced rearrangement reaction (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 163-173 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electron impact mass spectra of cyclophosphamide (1) are very sensitive towards experimental conditions in view of the kind of sample handling, the type of mass spectrometer used and the temperature of evaporation. The reason for this phenomenon is the elimination of HCl from the molecular ion by a specific 1,5-hydrogen transfer yielding an ion at m/z 224 which is structurally related to the bicyclic compound 4 with its typical fragment ions at m/z 175 and 147. Thermal excitation of the sample increases the intensity of this fragmentation pathway. The fragmentation pattern of 1 and the thermally induced rearrangement reaction has been elucidated by means of isotopic labelling, high-resolution data, metastable ion analysis and some tandem mass spectrometric experiments. Various samples of 1 monohydrate and its commercially available preparations, which are triturates with sodium chloride, differing in the crystal size distribution, showed nearly identical mass spectra on two different magnetic mass spectrometers, provided that the materials were introduced as solids under careful control of the evaporation temperature. The fragmentation via m/z 224 prevails in case of non-crystalline, pre-dissolved samples on one of the instruments used which might be explained by a differing construction of the ion source and the sample cup holder. The conclusions of Mruzek et al. concerning different proportions of stereoisomers in pharmaceutical preparations of 1 lack any analytical evidence.
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    B. A. Garetz and J. R. Lombardi. Advances in laser spectroscopy, volume 3. J. Wiley & Sons, Ltd. 1986 ISBN 0-471-90990-A £33.50 (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 183-183 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150312
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    Identification of metabolites of tiropramide in human urine (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 205-209 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The metabolites of tiropramide were extracted from the urine of healthy volunteers given tiropramide hydrochloride orally. Eight metabolites of tiropramide were found by gas chromatography/mass spectrometry. Three were identified on the basis of their mass spectra, retention times and comparison with synthetic standards. For the others a probable structure is proposed on the basis of their mass spectra.
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    URL: http://dx.doi.org/10.1002/bms.1200150404
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    Mass spectrometric characterization of some human metabolites of flumecinol (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 229-232 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mass spectrometric behaviour of six human metabolites formed by hydroxylation in various positions of the α-ethyl group or/and on the phenyl ring of 3-trifluoromethyl-α-ethyl-benzyhydrol (flumecinol) and seven related compounds has been studied. The electron impact mass (EI) spectra of these compounds show significant and characteristic effects of substituents, but many of them suffer from weakness or even from absence of the M+· peak owing to the very facile primary loss of the α-aliphatic chain, i.e. no direct information can be obtained about the size of the molecule and that of this chain. It is demonstrated for derivatives possessing a hydroxylated α-ethyl group that the difficulties in structural characterization due to the lack or weakness of M+· and [M + H]+ peaks in their EI and chemical ionization mass spectra, respectively, can be overcome by studying their silylated or boronated derivatives. Furthermore, silylation enables us to obtain a clear base for distinction of the primary and secondary alcohols of this type.
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    URL: http://dx.doi.org/10.1002/bms.1200150407
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    Synthesis of deuterium-labelled elliptinium and its use in metabolic studies (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 243-247 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 9-hydroxy-2-(U-2H3) methylellipticinium acetate (elliptinium) was synthesized with an isotopic purity of at least 96%. The structure was confirmed by proton nuclear magnetic resonance and direct probe fast atom bombardment mass spectrometry. A mixture of elliptinium and its deuterated analogue was administered intravenously to rats. In urine, after analysis by liquid chromatography/mass spectrometry (LC/MS), unchanged drug and N-acetylcysteinylelliptinium were found. In bile, after ion-pair extraction and LC/MS, the glutathionyl-elliptinium was found in addition to the parent drug and the N-acetylcysteine adduct.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200150502
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    Determination of boldenone sulfoconjugate and related steroid sulfates in equine urine by high-performance liquid chromatography/tandem mass spectrometry (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 283-289 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Sulfoconjugated anabolic steroids were separated by micro-bore high-performance liquid chromatography. The eluent was introduced into the atmospheric pressure ion source of the triple-quadrupole mass spectrometer via an ion spray liquid chromatograph/mass spectrometer interface operated in the negative ion mode. The limit of detection was 10 pg on-column by selected ion monitoring of the molecular ion and the response increased linearly over a concentration range of 2.4 orders of magnitude. Following work-up by a liquid-solid extraction procedure of equine urine samples, full-scan daughter ion spectra of boldenone sulfate could be obtained up to 17 days after a therapeutic dose of boldenone undecylenate to a horse.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150508
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  • 71
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    Laser desorption/fourier transform ion cyclotron resonance mass spectrometry: Digoxin, digitoxin, and their reduced and sugar-hydrolyzed metabolites (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 295-302 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mass spectra of digoxin and digitoxin (the most widely prescribed drugs for treatment of congestive heart failure) and a complete set of their 14 dihydro- and sugar-hydrolyzed metabolites have been obtained via laser desorption/ionization with a Fourier transform ion cyclotron resonance (LD/FT/ICR) mass spectrometer. The most intense peak is typically the pseudomolecular [M + K]+ ion, but fragment ions corresponding to loss of 1--3 sugars and hydroxyls are also observed. LD/FT/ICR mass spectra for all 16 compounds were produced with a single set of sample and spectrometer parameters. No matrix peaks are present. Finally, LD/FT/ICR provides dynamic mass accuracy within ≈5 ppm throughout a mass range of 404 〈 m/z 〈 819.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150510
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  • 72
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    Conjugation reactions of polyaromatic quinones to mono- and bisglutathionyl adducts: Direct analysis by fast atom bombardment mass spectrometry (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 329-332 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The conjugation products of several reactive quinones with glutathione have been identified by fast atom bombardment mass spectrometry. Appropriate conditions have been developed which enabled the direct, dynamic mass spectral analysis of spontaneous, as well as glutathione transferase catalysed conjugation reactions. Applications to a series of quinones provided the direct detection and differentiation of the formation of mono- and bisglutathionyl adducts between regioisomeric quinone substrates in that only 1,4-quinones yielded bisglutathionyl adducts, which were not observed for the 1,2-isomers.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150605
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    Collisional spectroscopy in structural characterization of melanins 2 - laser desorption experiments on bio- and synthetic tryptophan melaninsFor part 1 see Ref. 13. (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 353-355 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Melanins1 are naturally occurring macromolecules whose structural complexity appeared evident from the first researches of Quilico.2 Their structural characterization remains a difficult problem, mainly due to the physico-chemical properties of such compounds. Melanins are insoluble in organic solvents as well as aqueous solutions and are infusible. Consequently the traditional chemical degradation and physicochemical methods such as ultraviolet, infrared, 1H and 13C nuclear magnetic resonance, ESR (electron spin resonance), XPS (X-rays photoelectron spectroscopy) and X-ray diffraction have led, until now, to limited information on melanin chemical structure1,3.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150608
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  • 74
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    Automated measurement of the concentration and 13C enrichment of carbon dioxide in breath and blood samples using the finnigan MAT breath gas analysis system (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 365-367 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The operation and performance of the Finnigan MAT automated Breath Gas Analysis System for the routine analysis of 13C breath tests taken in 20-ml Vacutainers is described. Up to four samples per hour can be analysed with a standard deviation of δ13C of 〈0.05%o being achieved over the range 10-50 μmol CO2. The equipment can also be used for the automatic measurement of the concentration and 13C enrichment of CO2 derived from carbonate or bicarbonate solutions, including blood and other physiological fluids.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200150703
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  • 75
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    FAB and tandem mass spectrometry for endorphin- and ACTH peptides of molecular weight to 2000 (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 649-657 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Four β-endorphins (β-endorphin 6-17, 2-17, 1-16, and 1-17) and two adrenocorticotropic hormone (ACTH) peptides (ACTH 1-10 and (1-16)-NH2) were studied by using fast atom bombardment coupled with tandem mass spectrometry. The capability to reproduce metastable ion and collisionally activated decomposition spectra on two different commercial sector mass spectrometers in two different laboratories was found to be acceptable (deviations in relative abundance are less than ± 50%). The endorphin peptides fragment metastably or upon collisional activation to give abundant B-series ions as well as Y-series ions, whereas Y-series ions are the principal ionic species produced upon the desorption by fast atom bombardment. The ACTH peptides also fragment to give Y-series ions, but of relatively low abundance compared to those from the endorphins. For both sets of peptides, high-energy collisionally activated decomposition and metastable ion decomposition daughter ion spectra are precise, structurally informative - even for peptides up to m/z 2000 - and complementary to spectra of daughter ions produced by desorption ionization alone.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200151203
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  • 76
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    Analysis of sub-microgram quantities of nucleotides by fast atom bombardment mass spectrometry (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 547-551 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nucleotides of the structure P1,Pn-di(adenosine-5′)-n-phosphate (n = di- through penta-) in the form of salts, and P1,P4-di(guanosine-5′)tetraphosphate sodium salt have been analyzed by fast atom bombardment (FAB) mass spectrometry. A 0.2 molar solution of p-toluenesulfonic acid in glycerol has been evaluated as a matrix. In this matrix, the metal ions of the nucleotide salts are readily exchanged for protons, resulting in a simple spectrum with only one peak in the molecular ion region corresponding to the free phosphoric acid of the nucleotide plus or minus a proton (positive or negative mode), instead of the multiplicity of peaks arising from a series of metal and matrix adduct ions found with glycerol as matrix. The detection limit for analytes using this matrix is improved by a factor of ten compared to glycerol alone. It appears that the high acidity and the surfactant properties of p-toluenesulfonic acid both contribute to this result. Useful spectra are obtained from 250 ng of each of the above mentioned nucleotides, with the detection limit being somewhat lower in the positive mode. However, both positive and negative FAB spectra are useful and the results are complementary.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200151007
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    Nucleophilic reactions between biological conjugates and tetraalkylammonium ion pair reagents during desorption chemical ionization (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 571-576 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tetraalkylammonium salts, commonly used as ion pair reagents in chromatography, were found to react with biological conjugates under desorption chemical ionization conditions in a mass spectrometer. The reactions occur for aromatic glucuronide and glucoside conjugates using solid samples loaded on the direct exposure probe. Evidence is presented that several mechanisms contribute to the degradative alkylation of benzo(a)pyrene glucuronide. This undesirable process can be prevented by using ammonium or trialkylammonium instead of tetra-alkylammonium salts in the chromatographic separation. Nucleophilic attack on the tetraalkylammonium cations in the energized condensed phase was found to occur also for some simpler aromatic compounds.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200151010
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    A rapid method for the structural characterization of sulphated phlorotannins by negative ion fast atom bombardment mass spectrometry and acetylation on the target (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 595-602 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method for a rapid and direct structural determination of sulphated phlorotannins has been developed by using a combination of negative ion fast atom bombardment mass spectrometry and acetylation on the target. The structural variations of sulphated phlorotannins include: (i) the number of monomeric phloroglucinol units involved; (ii) the mode of their connectivity; (iii) the orientation of hydroxy groups on aromatic carbon atoms; (iv) the presence of the substituents other than hydroxy groups on aromatic carbon atoms; and (v) the number of sulphate esters on the hydroxy groups. Additionally, the acidic protons on the sulphate groups can be easily substituted by sodium or potassium cations, depending on the mode of isolation. In the negative ion mode, several ions were observed and a determination of molecular size and molecular parameters (i)-(v) appeared to be rather speculative. After adding diluted hydrochloric acid to the sample in order to substitute alkali ions for protons, the hydrolysis of sulphate groups has been observed. The acetylation on the target, however, represents a rapid method to observe the molecular ions, and from the mass differences the molecular parameters can be easily calculated. This procedure also demonstrates the general possibility of studying rapid chemical reactions by fast atom bombardment mass spectrometry.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200151104
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    Masthead (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988) 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200151201
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  • 80
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    The use of alkoxycarbonyl derivatives for the mass spectral analysis of drug-thioether metabolites. Studies with the cysteine, mercapturic acid and glutathione conjugates of acetaminophen (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 637-647 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Alkoxycarbonyl derivatives of the cysteine-, N-acetylcysteine- and glutathione conjugates of acetaminophen have been prepared in aqueous buffer solutions and their chromatographic and mass spectrometric properties examined. Structurally informative fragmentation patterns of the cysteine- and N-acetylcysteine derivatives were obtained when their methyl esters were subjected to analysis by direct insertion chemical ionization (CH4) mass spectrometry, although field desorption and liquid secondary ion mass spectrometric techniques were required in order to obtain satisfactory spectral data for derivatives of the glutathione adduct. Treatment of ethoxycarbonyl derivatives of the three acetaminophen metabolites with N-methyltrifluoroacetamide-based silylating reagents led to the formation of a common volatile product which was ideally suited to analysis by gas chromatography/electron impact mass spectrometry. A mechanism is proposed for the formation of this novel derivative, which appears to possess a benzo-1,3-thioxalane structure, and its mass spectral characteristics are reported. Finally, the utility of alkoxycarbonyl derivatives for the analysis of drug - thioether conjugates in biological fluids is discussed in terms of their advantages for aqueous phase derivatization, purification by high-performance liquid chromatography and characterization by mass spectrometry.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200151202
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    Bromo- and bromochloro-polynuclear aromatic hydrocarbons, dioxins and dibenzofurans in municipal incinerator fly ash (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 669-676 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A fly ash sample found to contain polychlorinated dioxins and dibenzofurans was analyzed for brominated analytes. Bromochloro-polynuclear aromatic hydrocarbons, dioxins and dibenzofurans, as well as bromo PAH were found in ppt to ppb concentrations. Analytical results were confirmed by high-resolution mass spectrometric accurate mass determinations and by tandem mass spectrometry.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200151205
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  • 82
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    Fast atom bombardment mass spectrometry of protected peptide segments (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 681-684 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200151207
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  • 83
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    Masthead (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988) 
    Details
    ISSN: 0886-9383
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020101
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    Diary (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. i 
    Details
    ISSN: 0886-9383
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020102
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    Identification and substructure analysis of oligosaccharide chains derived from glycoproteins by computer retrieval of high-resolution 1H-NMR spectra (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 11-27 
    Details
    ISSN: 0886-9383
    Keywords: Oligosaccharides ; Glycoproteins ; Identification ; Substructure analysis ; High-resolution ; 1H-NMR spectra ; Computer retrieval ; Reproducibility ; Chemical shifts ; Similarity index ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Based on a statistical model of the reproducibility of NMR spectral features, a system for computer retrieval of high-resolution 1H-NMR spectra of glycoprotein carbohydrates has been developed. For corresponding peaks in an unknown and a reference spectrum, a similarity index based on the reproducibility of the chemical shifts is calculated. In addition, a second similarity index, based on the probability distribution of the percentage of non-matching peaks, has been developed. From these two similarity indices, a combined similarity index using the recall-reliability function as the optimizing criterion has been derived.First results indicate that the ‘1H-NMR reproducibility-based retrieval’ (‘1HRR’) system offers good perspectives for both identification and substructure analysis.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020104
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    Chance classifications by non-parametric linear discriminant functions (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 1-10 
    Details
    ISSN: 0886-9383
    Keywords: Linear discriminant functions ; Pattern recognition ; Monte Carlo simulations ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In applications of pattern recognition techniques to problems in chemical fingerprinting, only limited knowledge about the underlying statistical distribution of the data is generally available. This means that non-parametric methods must be used. Non-parametric discriminant functions have been used to provide insight into relationships contained within sets of chemical measurements. However, classification based on random or chance separation can be a serious problem. Monte Carlo simulation studies have been carried out to assess the probability of chance classification for non-parametric linear discriminants. The level of expected chance classification is a function of the number of observations (the number of samples), the dimensionality of the problem (the number of independent variables per observation), class membership distribution and the covariance structure of the data being examined. An approach for assessing the level of significance of classification scores obtained from real training sets will be presented. These simulation studies establish limits on the approaches that can be taken with real data sets so that chance classification are improbable, and provide information necessary for integrating the data analysis into the overall experimental design.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020103
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    Taxonomy based on chemical constitution: Differentiation of Africanized honey-bees from European honey-bees (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 29-37 
    Details
    ISSN: 0886-9383
    Keywords: Pattern recognition ; Principal component analysis ; Linear discriminant analysis ; Classification ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Gas chromatography and pattern recognition methods have been used to develop a potential method for differentiating between European and Africanized honey-bees based on chemical constitution. 243 European, African and Africanized honey-bees were characterized by 40-peak GCs of cuticular hydrocarbon extracts. Discriminants were developed that correctly classified the bees, and these discriminants were used successfully to classify bees of unknown origin, including hybrids.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020105
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  • 88
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    Expert system for knowledge-based modelling of analytical laboratories as a tool for laboratory management (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 49-65 
    Details
    ISSN: 0886-9383
    Keywords: Laboratory organization ; Expert systems ; Digital simulation ; Decision support ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An expert system (LABGEN) is presented for decision support in analytical laboratories by means of digital simulation. In an interactive manner, LABGEN constructs simulation models of laboratory organizations. It makes use of a database of model fragments and applies rules in order to prevent the user providing redundant information and to prevent inconsistent models being constructed. The models are written in the dedicated simulation language SIMULA. After compilation they can be used for simulation experiments. LABGEN can be applied to a wide range of laboratory organizations. An example of the application of LABGEN is presented.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020107
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  • 89
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    Selection of optimal regression models via cross-validation (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 39-48 
    Details
    ISSN: 0886-9383
    Keywords: Regression modelling ; Cross-validation ; Bootstrap ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A general problem arising in the development of regression models is the selection of the optimal model. Whenever a feature selection procedure, such as step forward, backward elimination, best subset or all possible combinations, or when a data compression approach, such as principal components or partial least-squares regression, is used, the question of how many regression terms to include in the final model must be addressed.This work describes the evaluation of four different criteria for selection of the optimal predictive regression model using cross-validation. The results obtained in this work illustrate the problems which can arise in the analysis of small or inadequately sampled data sets. The common approach, selecting the model which yields the absolute minimum in the predictive residual error sum of squares (PRESS), was found to have particularly poor statistical properties. A very simple change to a criterion based on the first local minimum in PRESS will provide a significant improvement in the cross-validation result. A criterion based on testing the significance of incremental changes in PRESS with an F-test may provide more robust performance than the local minimum in PRESS method.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020106
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  • 90
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    The effect of interferences and calbiration design on accuracy: Implications for sensor and sample selection (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 67-79 
    Details
    ISSN: 0886-9383
    Keywords: Experimental design ; Multivariate calibration ; Variable selection ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Methods of multivariate calibration use models that relate spectral data or sensor array responses to the concentrations of analytes. The goal is to insure that the calibration model can accurately estimate analyte concentrations in unknown samples not contained in the calibration set. The sensors or spectral channels (e.g. wavelengths) selected for incorporation in the model, as well as the samples selected for the calibration step, are known to have an effect on the accuracy of analysis for unknown samples. This work provides a fundamental treatment of this effect and derives criteria for optimal selection. Additionally, a proof is given for the advantage of having more sensors and calibration samples than analytes - the overdetermined case.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020108
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  • 91
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    Monte Carlo studies of non-parametric linear discriminant functions (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 85-89 
    Details
    ISSN: 0886-9383
    Keywords: Linear discriminant functions ; Pattern recognition ; Monte Carlo simulations ; Chance classification ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Classification rules using non-parametric linear discriminant functions are often developed from training sets that are not linearly separable. In these situations it is a common practice among inexperienced workers to use many different pattern recognition methods and then select the results that look the best. However, this practice will only increase the risk of spurious results. To document this, we recently carried out a series of Monte Carlo simulation studies to assess the level of chance classification for two different classification algorithms. The level of chance classification for a given dichotomy is found to vary with the choice of the non-parametric linear discriminant function employed. Although previous workers have indicated that the degree of separation in the data due to chance is only a function of the object-to-descriptor ratio, the results of this study suggest otherwise.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020110
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  • 92
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    Principal component variable discriminant plots: A novel approach for interpretation and analysis of multi-class data (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 81-84 
    Details
    ISSN: 0886-9383
    Keywords: Multiclass analysis ; Covariance correlation display ; Variable Discriminant plots ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Principal component analysis is a useful method for analysing data-matrices. By analysing separate class models, i.e. disjoint principal component modelling as in the SIMCA or FCVPC programs (developed for supervised and unsupervised principal component analysis respectively), the principal component variance/covariance decomposition (class models) may be used to investigate and interpret the data-structure of separate classes. The potential of comparing the loadings of variables on subsequent eigenvectors in two class models where the same variables have been used will give information for determining how the variance/covariance in the two datasets differ. This information may then be used either to formulate a hypothesis or to select variables which are specific for the different classes.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020109
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  • 93
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    Announcements (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 91-92 
    Details
    ISSN: 0886-9383
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020111
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    Electronic Resource
    Announcement (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. i 
    Details
    ISSN: 0886-9383
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020202
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  • 95
    Electronic Resource
    Electronic Resource
    Masthead (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988) 
    Details
    ISSN: 0886-9383
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020201
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  • 96
    Electronic Resource
    Electronic Resource
    Estimation of prediction error for multivariate calibration (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 93-109 
    Details
    ISSN: 0886-9383
    Keywords: Multivariate calibration ; Error estimation ; Confidence intervals ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: When arrays of non-selective sensors or overlapping spectra are used for chemical analysis, multivariate calibration must be used to relate the instrument responses to individual analytes. Using a set of carefully selected calibration samples, a multivariate mathematical model is constructed for one or more analytes. If this step is successful, the model can be used to predict the concentrations of these analytes in prospective samples. Previously, the equations required to estimate the errors in the predicted concentrations, and from these the confidence intervals, were not available because the three sources of error (measured responses from calibration data, concentrations of the analytes in the calibration set and measured responses from the unknown sample) propagated in a non-linear manner not amenable to statistical analysis. A new theory for error propagation is developed. The theory developed herein does not require estimates of the actual three sources of errors mentioned above and therefore is easy to implement. Data from near-infrared reflectance spectrometry of wheat samples were used to test the equations derived from the theory. Complete agreement between the true prediction errors and those estimated from the theory is demonstrated.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020203
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  • 97
    Electronic Resource
    Electronic Resource
    The application of submatrix analysis to disordered spectroscopic data (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 111-119 
    Details
    ISSN: 0886-9383
    Keywords: Oscillating reactions ; Rank determination ; Submatrix analysis ; Principal component analysis ; Spectroscopy ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Submatrix analysis has been extended to systems in which the values of adjustable parameters are not known. The technique is illustrated by application to phosphoric acid and to the chlorite-iodide oscillating reaction.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020204
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  • 98
    Electronic Resource
    Electronic Resource
    A method for detecting potentially unreliable estimates when using the Burdick/Rayens model for estimating linear mixing proportions (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 121-136 
    Details
    ISSN: 0886-9383
    Keywords: Discriminant analysis ; Linear mixtures ; Residual vectors ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In an earlier paper by Burdick and Rayens a model was developed which uses discriminant analysis to construct estimates of linear mixing proportions. In this paper a method is proposed for identifying potentially unreliable estimates when using the Burdick/Rayens model. It is also shown to be useful in detecting irregularities in the sample data. The methodology is based on the lengths of residual vectors and is demonstrated within the context of polychlorinated biphenyl mixtures.
    Additional Material: 13 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020205
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  • 99
    Electronic Resource
    Electronic Resource
    Principal component regression in NIR analysis: Viewpoints, background details and selection of components (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 155-167 
    Details
    ISSN: 0886-9383
    Keywords: Principal component regression ; Multivariate calibration ; Near-infrared reflectance ; Prediction ability ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this paper we present formulae for prediction error related to principal component regression (PCR). The difference between PCR and ordinary least-squares (LS) regression is discussed in relation to these formulae. This discussion is used as a basis for a treatment of PCR in NIR analysis. The theory is illustrated by two examples from NIR analysis.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020207
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  • 100
    Electronic Resource
    Electronic Resource
    Estimation of second-order chemical kinetic parameters by using information-based extended Kalman filtering (1988)
    New York, NY : Wiley-Blackwell
    Journal of Chemometrics 2 (1988), S. 137-154 
    Details
    ISSN: 0886-9383
    Keywords: Recursive parameter estimation ; Digital filtering ; Kinetic analysis ; Kalman filtering ; Computational efficiency ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The extended Kalman filter has been used to estimate initial reactant concentrations and rate constants for rate-based chemical assays employing a second-order chemical reaction. Application of first- and second-order models to data permits reaction order identification by examining either the filter innovations or the evolution of the filter states. Because of non-linearities in the second-order kinetic model, repetitive filtering is necessary for convergence to reliable state estimates. Reduction of the filter calculation burden is investigated through the use of information-based filter methods, and it is demonstrated that substantial decreases in the computational burden are possible without loss of filter accuracy. These decreases make possible the application of second-order filters on large data sets, and they make real-time filtering possible with a fast processor.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cem.1180020206
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