Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1995-1999  (9)
  • 1
    Electronic Resource
    Electronic Resource
    Effect of electrostatic interactions on the structure and dynamics of a model polyelectrolyte. I. Diffusion (1998)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 109 (1998), S. 7556-7566 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The dynamics of a 20 base pair oligonucleotide is studied by dynamic light scattering-photon correlation spectroscopy and depolarized Fabry–Perot interferometry. The 20 base pair oligonucleotide is a well-defined, albeit short, rigid rod molecule that serves as a model for polyelectrolyte solution dynamics. The effects of added salt on the solution rotational and translational dynamics are examined in detail as functions of the 20-mer concentration. Coupled mode theory together with counterion condensation theory gives good predictions for the effects of salt on the translational diffusion of the 20-mer at the relatively low oligonucleotide concentrations studied. Comparison of the experimental results with these theories shows that the effective charge density of the polyion in solution is approximately equal to the reciprocal of the product of the Bjerrum length and the counterion charge, νeff≅1/NλB. Calculation shows that the numerical solution of the coupled mode theory matrix gives a better fit of our measured polyion diffusion coefficients than the approximate equation derived by Lin, Lee, and Schurr. Simple approximations for the effective rod length, Leff=L+κ−1, and effective rod diameter, deff=d+κ−1, are used to model the thermodynamic-hydrodynamic interactions for charged rodlike molecules and to make predictions for the diffusion second virial coefficient as a function of added salt concentration. This alternative to the coupled mode theory also gives good agreement with experiment. The rotational diffusion constants of the oligonucleotide measured by depolarized Fabry–Perot interferometry show a slowing down of the rotation at low added salt concentrations as the oligonucleotide concentration is increased. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.477377
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The Tir-binding region of enterohaemorrhagic Escherichia coli intimin is sufficient to trigger actin condensation after bacterial-induced host cell signalling (1999)
    Oxford BSL : Blackwell Science Ltd
    Molecular microbiology 34 (1999), S. 0 
    Details
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Enterohaemorrhagic Escherichia coli (EHEC) has emerged as an important agent of diarrhoeal disease. Attachment to host cells, an essential step during intestinal colonization by EHEC, is associated with the formation of a highly organized cytoskeletal structure containing filamentous actin, termed an attaching and effacing (A/E) lesion, directly beneath bound bacteria. The outer membrane protein intimin is required for the formation of this structure, as is Tir, a bacterial protein that is translocated into the host cell and is thought to function as a receptor for intimin. To understand intimin function better, we fused EHEC intimin to a homologous protein, Yersinia pseudotuberculosis invasin, or to maltose-binding protein. The N-terminal 539 amino acids of intimin were sufficient to promote outer membrane localization of the C-terminus of invasin and, conversely, the N-terminal 489 amino acids of invasin were sufficient to promote the localization of the C-terminus of intimin. The C-terminal 181 residues of intimin were sufficient to bind mammalian cells that had been preinfected with an enteropathogenic E. coli strain that expresses Tir but not intimin. Binding of intimin derivatives to preinfected cells correlated with binding to recombinant Tir protein. Finally, the 181-residue minimal Tir-binding region of intimin, when purified and immobilized on latex beads, was sufficient to trigger A/E lesions on preinfected mammalian cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2958.1999.01574.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Video-assisted Thoracoscopic Surgery for Spontaneous Hemopneumothorax (1998)
    Springer
    World journal of surgery 22 (1998), S. 23-27 
    Details
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. We operated on 403 patients with spontaneous pneumothorax between 1992 and 1996. Among these cases, 11 (2.7%) were spontaneous hemopneumothorax. The patients were all men, with ages ranging from 19 to 28 years (mean 23.8 years). The amount of blood drainage ranged from 650 to 2300 ml. Video-assisted thoracoscopic surgery was performed on these patients within 1 day after admission. The sources of bleeding were in the parietal and visceral pleurae of ruptured bullae ( n = 6), the parietal pleura ( n = 4), or the visceral pleura ( n = 1). During operation, the ruptured bullae can be managed by an endoscopic linear stapler for a bullectomy, and the bleeding parietal pleura of the torn adhesion can be coagulated directly. Postoperative recovery of the 11 patients was uneventful, and they were discharged 4 to 10 days after the operation. No recurrence of spontaneous hemopneumothorax or any other complications occurred during follow-up. Thus spontaneous hemopneumothorax can be readily managed by cauterizing a bleeding site where appropriate, excising the apicocystic disease, and pleurodesis. As a minimally invasive method, video-assisted thoracoscopic surgery may be considered an initial treatment procedure in patients with spontaneous hemopneumothorax.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002689900344
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Video-assisted endoscopic esophagectomy with stapled intrathoracic esophagogastric anastomosis (1995)
    Springer
    World journal of surgery 19 (1995), S. 745-747 
    Details
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé On peut enlever l'oesophage thoracique soit par voie transhiatale soit par thoracotomie. L'incision, relativement longue, et l'écartement des côtes nécessaires sont, cependant, sources de douleurs et perturbent la mécanique de la paroi thoracique. Aujourd'hui, grâce à la chirurgie vidéo-assistée, on peut envisager l'ablation de beaucoup de lésions intrathoraciques par de toutes petites incisions. Depuis Mars 1992, nous avons effectué 20 oesophagectomies suivies de rétablissement de continuité par thoracoscopie droite chez 16 hommes et 4 femmes dont l'âge moyen était de 56 ans. Les indications ont été un cancer de l'oesophage chez 17 (cancer épidermoïde chez 12 et adénocarcinome chez 5), et une sténose caustique chez trois patients. D'après nos résultats, l'oesophagectomie suivie de rétablissement de continuité par chirurgie vidéo-assistée est associée à moins de traumatisme, moins d'inconfort postopératoire et à une meilleure récupération fonctionnelle. Notre expérience initiale montre qu'elle est réalisable et efficace.
    Abstract: Resumen El esófago torácico fue resecado a través del método transhiatal o mediante toracotomía abierta. La larga incisión torácica y la separación de las costillas resultó en mucho dolor y considerable interferencia con la mecánica de la pared torácica. En la actualidad, gracias al desarrollo de los procedimientos endoscópicos video-asistidos, un número significativo de lesiones intratorácicas son susceptibles de resección a través de incisiones pequeñas. A partir de marzo de 1992 bemos intentado 20 esofagectomías con reconstrucción utilizando un abordaje toracoscópico derecho en 16 hombres y 4 mujeres cuya edad promedio fue 56 años. Las indicaciones para la intervención fueron cáncer del esófago en 17 pacientes (carcinoma escamocelular en 12, adenocarcinoma en 5) y estenosis cáustica en 3. Es nuestra impresión que la esofagectomía y reconstrucción endoscópica video-asistida produce menos trauma y menos incomodidad postoperatoria con recuperación funcional más rápida. Nuestra experiencia inicial demuestra que el procedimiento es factible y efectivo.
    Notes: Abstract Thoracic esophagus was usually removed through the transhiatal approach or via an open thoracotomy. The long incision and spreading of the ribs usually resulted in much pain and interference with chest wall mechanics. Today, with the development of a video-assisted endoscopic procedure, many intrathoracic lesions can be removed through small incision. Since March 1992 we have attempted 20 esophagectomies and reconstruction using a right thoracoscopic approach in 16 males and 4 females whose average age was 56 years. Indications for its use were esophageal cancer in 17 patients (squamous cell carcinoma in 12 patients, adenocarcinoma in 5) and caustic stenosis in 3. It is our impression that video-assisted endoscopic esophagectomy and reconstruction potentially causes less trauma, less postoperative discomfort, and a rapid functional recuperation. Our initial experiences showed that it is a feasible, effective procedure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00295920
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Thoracoscopic Surgery for Spontaneous Pneumothorax (1999)
    Springer
    World journal of surgery 23 (1999), S. 1133-1136 
    Details
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Spontaneous pneumothorax in apparently healthy individuals is a relatively common occurrence. The management of patients with spontaneous pneumothorax remains controversial. With the advances in thoracoscopic techniques and instrumentation, video-assisted thoracic surgery (VATS) is now accepted by many as the procedure of choice for surgical treatment of spontaneous pneumothorax. We report our combined experience with 757 patients who suffered from recurrent or persistent spontaneous pneumothorax treated by VATS over a 5-year period. Surgical indications included persistent air leak (n= 165), recurrence (n= 325), radiologically demonstrated huge bulla (n= 12), spontaneous hemopneumothorax (n= 13), incomplete expansion of the lung (n= 212), and bilateral involvement (n= 30). Several surgical procedures were undertaken, based on the thoracoscopic findings: endoscopic stapled bullectomy (n= 312), argon beam coagulation (n= 6), endoscopic suturing (n= 52), and endoloop ligation (n= 352). In 49 cases, mechanical or chemical pleurodesis was the only procedure performed. There were no mortalities or intraoperative hazards. Complications consisted of wound infections (n= 16), localized empyema (n= 2), chest wall bleeding (n= 1), and persistent air leaks (bulla type III) (n= 31). The median duration of the operation was 55 minutes (15–160 minutes), and the average postoperative hospital stay was 4.5 days (range 0–27 days). There were 16 recurrences (2.1%), after a mean follow-up of 30 months (range 1–60 months). Seven patients had recurrence from 9 to 17 months after stapled bullectomy. All the remaining patients had recurrence after failed pleurodesis. On the basis of our results, we conclude that video-assisted thoracoscopic management allows effective, safe performance of standard surgical procedures, avoiding a formal thoracotomy incision. We consider thoracoscopy the treatment of choice for patients with pneumothorax requiring surgical therapy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002689900636
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Technique of Video-assisted Thoracoscopic Surgery for the Spine: New Approach (1997)
    Springer
    World journal of surgery 21 (1997), S. 358-362 
    Details
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Although video-assisted thoracoscopy has only recently been applied to treat a variety of thoracic spine lesions, many problems and difficulties are encountered with this technique owing to limited trocar space and lack of suitable endoscopic instruments. Between November 1995 and March 1996, we practiced a new approach for video-assisted thoracoscopic surgery, the “extended manipulating channel method,” for treating 18 patients with thoracic spinal lesions endoscopically. The thoracoscopic portals were made larger (usually 3–4 cm) and placed slightly more posterior than usual, which allows use of a combination of conventional spinal instruments and video-assisted thoracoscopy to enter the chest cavity and be manipulated similar to that with techniques used for standard open surgical procedures. In our series the endoscopic spinal procedures included biopsy only ( n = 1), thoracic discectomy ( n = 1), multilevel anterior discectomy and fusion ( n = 1), corpectomy for decompression ( n = 4), decompressions and interbody fusions ( n = 10), and internal instrumentations ( n = 4). Throughout the operation only one trocar was used for introducing the thoracoscope. There were no intraoperative deaths, and no patients showed neurologic deterioration due to the procedures. We conclude that such a technique makes thoracoscopy-assisted spinal surgery simpler and easier and has proved to be an effective, promising procedure. It does not appear to compromise the therapeutic goals set for the patients. The intraoperative vessel bleeding can be easily controlled, and the number of portals for the procedures can be reduced (on average, three portals are enough). Few endoscopic materials were used with our patients, and thus the total economic cost to the patients was reduced.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00012253
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    In-vitro and in-vivo evaluation of the drug-drug interaction between fluvoxamine and clozapine (1999)
    Springer
    Psychopharmacology 145 (1999), S. 91-98 
    Details
    ISSN: 1432-2072
    Keywords: Key words Clozapine ; Fluvoxamine ; CYP 450 ; Drug-drug interaction ; In-vitro ; In-vivo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The drug-drug interaction between fluvoxamine (FLV) and clozapine (CLZ) was evaluated by in-vitro and in-vivo methods. In-vitro studies were conducted using human hepatic microsomal preparations with standard chemical inhibitors of the cytochrome P450 (CYP 450) isozyme system. Furafyline, FLV, troleandomycin (TAO) and erythromycin were used as the chemical inhibitors. For the in-vivo study, nine male schizophrenic patients were administered a single dose of CLZ 50 mg on two separate occasions with a 2-week FLV treatment of 50 mg twice a day in between each CLZ dose. Blood samples were obtained over 48 h following CLZ administration. CLZ and its two principle metabolites, clozapine N-oxide (CNO) and desmethylclozapine (DCLZ), were measured by high performance liquid chromatography with ultraviolet detection for both in-vitro and in-vivo studies. The in-vitro formation of DCLZ was inhibited by furafyline and FLV by 42.0% and 48.5% (P 〈 0.01), respectively. TAO and erythromycin had only modest inhibition effects on DCLZ formation of 18.3% and 21.0% (P = NS), respectively. CNO in-vitro formation was significantly reduced by TAO and erythromycin by 44.5% and 45.0% (P 〈 0.01), respectively. Furafyline and FLV had only modest effects of 19.2% and 8.5% (P = NS), respectively. In schizophrenic patients, FLV resulted in a pronounced increased in CLZ plasma concentrations with the total mean CLZ AUC increased by a factor of 2.58 from 780.8 ng/ml per hour to 2218.0 ng/ml per hour (P 〈 0.001). All patients were sedated during combined FLV and CLZ use. During FLV treatment, CNO and DCLZ AUC both decreased by 18.8% (P = 0.07) and 9.0% (P = NS), respectively. These results indicate that in-vitro evaluations may not always accurately reflect changes in drug-drug interaction observed in-vivo. Careful patient monitoring is recommended during FLV/CLZ co-administration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002130051036
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Raising pyrolysis yield of preceramic polymers of silicon carbonitride (1995)
    Springer
    Journal of materials science 30 (1995), S. 4463-4468 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Polymeric precursors for silicon carbonitrides are prepared by three synthetic routes starting with ammonolysis of dichloromethylsilane (CH3SiHCl2). Two methods for raising pyrolysis yield are investigated. One method is to enhance the degree of crosslinking by copolymerizing with trichlorosilane (SiHCl3) consecutively. The other is to leach out the less soluble macromolecules in the polymer precursor by organic solvents. A 92% pyrolysis yield can be reached through combining these two methods. Those precursors with higher yields are characterized with weight losses and heat events during pyrolysis shifting towards higher temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00361532
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Candida Rugosa Lipase Catalyzed Esterification of Racemic Ibuprofen with Butanol: Racemization of R-Ibuprofen and Chemical Hydrolysis of S-Ester Formed (1998)
    Springer
    Biotechnology letters 20 (1998), S. 455-458 
    Details
    ISSN: 1573-6776
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The chemical treatment of products obtained from Candida rugosa lipase catalyzed enantioselective esterification of racemic ibuprofen with n-butanol in isooctane was studied. After a complete separation of the unreacted R-ibuprofen from the S-ester formed, the R-ibuprofen was racemized and the S-ester was chemically hydrolyzed to S-ibuprofen with the same enantiomeric excess as that of the ester before hydrolysis. A cyclic process of preparing S-ibuprofen from its racemate with lipase catalysis in organic solvent is therefore feasible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005460808406
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...