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
  • 1
    Electronic Resource
    Electronic Resource
    Vortex interaction and mixing in a driven gaseous axisymmetric jet (1999)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 11 (1999), S. 3401-3415 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Vortex formation and merging are investigated in the near field of a driven axisymmetric jet. Acoustic forcing is used to obtain repeatable vortex pairing events, and simultaneous passive scalar and cold-chemistry planar laser-induced flourescence are used to obtain instantaneous images of molecularly mixed jet fluid fraction. The time-varying scalar dissipation field and area-averaged stirredness of the vortex core region are measured at various stages of vortex interaction. These mixing properties are analyzed in conjunction with the observed vortex dynamics, such as the time-dependent vortex convection velocity. The results indicate that there are several phases of the pairing event with distinct mixing characteristics, including vortex roll-up, interaction, coalescence, and reentrainment. Vortex roll-up is nearly laminar with molecular diffusion between the layers of jet and co-flow fluid. The most dramatic change in the mixing state of the leading vortex, which includes the appearance of a uniformly mixed core region, occurs as the trailing vortex approaches and interferes with co-flow fluid entrainment. Vortex coalescence is marked by gross deformation and stretching of the trailing vortex, and rapid homogenization of the diffusion layers. Finally, re-entrainment of pure fluid after the pairing event results in an elongated, nonrotating structure. These stages of vortex pairing correspond to the temporal evolution of vorticity observed in previous studies. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.870199
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Termination of Living Anionic Polymerizations Using Chlorosilane Derivatives: A General Synthetic Methodology for the Synthesis of End-Functionalized Polymers (1995)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 117 (1995), S. 3380-3388 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00117a008
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Influence of Charge and Polarity on the Redox Potentials of High-Potential Iron-Sulfur Proteins: Evidence for the Existence of Two Groups (1995)
    s.l. : American Chemical Society
    Biochemistry 34 (1995), S. 14675-14686 
    Details
    ISSN: 1520-4995
    Source: ACS Legacy Archives
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/bi00045a008
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Integrins at the neuromuscular junction are important for motoneuron survival (1999)
    Oxford, UK : Blackwell Science Ltd
    European journal of neuroscience 11 (1999), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: During development motoneurons depend on target contact for their survival. Following injury to the sciatic nerve in neonatal rats, a large proportion of motoneurons die. However, the same injury inflicted at 5 days of age results in no loss of motoneurons. This critical period of postnatal development coincides with the time during which there is a significant increase in the release of transmitter from the nerve terminals at the neuromuscular junction. We have proposed that the role of the target muscle cell during this period is to induce this up-regulation of transmitter release from motor nerve terminals. It has been shown that stretch-induced increase in transmitter release from frog motor nerve terminals is accomplished via an integrin-dependent mechanism. In this study we examined the role of integrins at the rat neuromuscular junction in motoneuron survival. We found that blocking integrin binding at the developing neuromuscular junction delayed the increase in choline acetyltransferase activity that normally takes place during the early postnatal period, and resulted in motoneuron death. Furthermore, the maturation of those motoneurons that survived was delayed so they remained susceptible to subsequent nerve injury. These results support the possibility that integrins, by their involvement in modulating transmitter release, can influence motoneuron survival.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1460-9568.1999.00749.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Structure of Cytochrome c' from Rhodobacter capsulatus Strain St Louis: An Unusual Molecular Association Induced by Bridging Zn Ions (1997)
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 53 (1997), S. 658-664 
    Details
    ISSN: 1399-0047
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Rhodobacter capsulatus strain St Louis cytochrome c′ (RCCP-SL) has been crystallized and the structure solved by molecular replacement. It was refined at 2.1 Å resolution to an R value of 18.4%, and compared with Rhodobacter capsulatus strain M110 cytochrome c′ (RCCP-M110). Although these two proteins are very similar in sequence and structure, the intermolecular interaction is largely different. In RCCP-M110, the molecules dimerize through interaction of helix B to form an antiparallel arrangement. When crystallized in the presence of Zn ions, molecules of RCCP-SL were found to be arranged as linear polymers connected by the bridging Zn ions. The changes in conformation of the side chains induced by binding of the Zn ions, by the substitution of Glu90 for Asp90, and by the different arrangement of the molecules, are discussed in detail.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0907444997005805
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Crystallization and preliminary X-ray study of a new crystal form of cytochrome c' from Rhodobacter capsulatus (1996)
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 52 (1996), S. 199-200 
    Details
    ISSN: 1399-0047
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: A new crystal form of diheme cytochrome c′ from Rhodobacter capsulatus has been obtained and preliminary crystallographic experiments have been performed. The crystals belong to the space group P21212 with unit-cell dimensions of a = 47.82, b = 72.59, c = 34.32 Å. The assumption that an asymmetric unit of the crystal contains one half of the homodimer molecule indicates that the monomers in the dimeric molecule may be related by a crystallographic twofold axis. Crystals diffract up to 1.7 Å resolution using the X-ray beam from synchrotron radiation, and 11 127 unique structure factors were obtained with an Rmerge of 7.1% from 52 922 indexed reflections. Structure analysis by means of molecular-replacement methods is now underway.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0907444995010936
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Zelluläre Heterogenität vaskulärer Myozyten in normalen und arteriosklerotisch veränderten humanen Koronargefäßen (1998)
    Springer
    Zeitschrift für Herz-, Thorax- und Gefässchirurgie 12 (1998), S. 40-47 
    Details
    ISSN: 0930-9225
    Keywords: Schlüsselwörter Vaskuläre glatte Muskelzellen – Koronararterien – Arteriosklerose – Zytoskelett-Proteine ; Key words Vascular smooth muscle cells – coronary arteries – arteriosclerosis – cytoskeletal proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary This study was undertaken to investigate cellular heterogeneity of smooth muscle cells in normal and arteriosclerotic coronary arteries. Tissue samples from human coronary arteries obtained at autopsy were analyzed by immunoblotting and immunohistochemical techniques for the expression of cytoskeletal proteins. Vinculin, myosin light chain kinase (MLCK), caldesmon, and alpha-actin were homogeneously expressed among smooth muscle cells of normal intima and media. In normal adventitia, however, these cytocontractile marker proteins were virtually absent. Desmin-positive cells were heterogeneously distributed throughout the media and intima of normal coronary arteries, but were missing in the adventitia. All human vascular cells including those of adventitia expressed vimentin. In arteriosclerotic plaques, the content of vinculin, MLCK, caldesmon, and alphaactin was less than in normal media and intima, while the amount of vimentin appeared to be unchanged. Using pancytokeratin antibody Lu5 in immunoblotting and immunohistochemical techniques, cytokeratin-producing smooth muscle cells could not be identified. Our results showing cellular heterogeneity of differentiated vascular myocytes are discussed in relation to the recent demonstration of different cell types observed in carotid arteries of adult dogs.
    Notes: Zusammenfassung In dieser Studie wurde die zelluläre Heterogenität von glatten Muskelzellen in normalen und arteriosklerotisch veränderten Koronargefäßen untersucht. Autoptisch gewonnene Gewebeproben von humanen Koronararterien wurden mit Immunoblotting- und immunhistochemischen Methoden auf die Expression von Zytoskelett-Proteinen untersucht. Vinculin, Myosin-Leichtketten-Kinase (MLCK), Caldesmon, und alpha-Aktin wird homogen in vaskulären Myozyten der Media und Intima normaler Koronararterien exprimiert. In normaler Adventitia konnten diese zytokontraktilen Markerproteine nicht nachgewiesen werden. Einige Desmin-positive Zellen fanden sich verstreut in der Media und Intima normaler Koronararterien, fehlten aber vollständig in der Tunica adventitia. Alle humanen Gefäßzellen einschließlich der Adventitiazellen exprimierten Vimentin. In arteriosklerotischen Plaques war der zelluläre Gehalt an Vinculin, MLCK, Caldesmon und alpha-Aktin geringer als in mormaler Media und Intima, während die Menge von Vimentin nicht vermindert war. Unter Verwendung des Panzytokeratin-Antikörpers Lu5 konnten mit Immunoblotting- und immunhistochemischen Techniken keine Zytokeratin-synthetisierenden glatten Muskelzellen identifiziert werden. Unsere Ergebnisse, die eine zelluläre Heterogenität von vaskulären Myozyten in humanen Koronararterien aufzeigen, werden im Hinblick auf kürzlich veröffentlichte Studien über verschieden differenzierte glattmuskuläre Zelltypen in Karotisgefäßen von Hunden diskutiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003980050014
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Podocyte number predicts long-term urinary albumin excretion in Pima Indians with Type II diabetes and microalbuminuria (1999)
    Springer
    Diabetologia 42 (1999), S. 1341-1344 
    Details
    ISSN: 1432-0428
    Keywords: Key words Type II diabetes mellitus ; diabetic nephropathies ; epithelial cell ; glomerulus ; Indians ; North American.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Aims/hypothesis. The predictive value of glomerular structure on progression of renal disease was examined in patients with Type II (non-insulin-dependent) diabetes and microalbuminuria (urinary albumin-to-creatinine ratio = 30–299 mg/g). Methods. Kidney biopsy specimens were obtained from 16 diabetic Pima Indians (6 men, 10 women). Progression of renal disease was assessed by measuring urinary albumin excretion 4 years after the biopsy (UAE4 years) and by computing the change in urinary albumin excretion during the study (Δ UAE). Results. At baseline, the duration of diabetes averaged 13.3 years (range = 4.0–23.8 years) and the mean glomerular filtration rate was 159 ml · min–1· 1.73m–2 (range = 98 – 239 ml · min–1· 1.73m–2). Median urinary albumin excretion was 67 mg/g (range = 25–136 mg/g) and it increased to 625 mg/g (range = 9–13471 mg/g) after 4 years; 10 subjects (63 %; 4 men, 6 women) developed macroalbuminuria (urinary albumin-to-creatinine ratio ≥ 300 mg/g). Neither mean arterial pressure nor HbA1 c changed substantially during follow-up. Among the glomerular morphologic characteristics, the number of visceral epithelial cells, or podocytes, per glomerulus was the strongest predictor of renal disease progression (UAE4 years, r = –0.49, p = 0.05; ΔUAE, r = –0.57, p = 0.02), with fewer cells predicting more rapid progression. Glomerular basement membrane thickness did not predict progression (UAE4 years, r = 0.11, p = 0.67; ΔUAE, r = 0.09, p = 0.73) and mesangial volume fraction had only a modest effect (UAE4 years, r = 0.42, p = 0.11; ΔUAE, r = 0.48, p = 0.06). Conclusion/interpretation. Whether lower epithelial cell number per glomerulus among those that progressed was due to cellular destruction, a reduced complement of epithelial cells, or both is uncertain. Nevertheless, these findings suggest that podocytes play an important part in the development and progression of diabetic renal disease. [Diabetologia (1999) 42: 1341–1344]
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001250051447
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Feldtheoretische Berechnung der Streuinduktivitäten von Leistungstransformatoren mit der Randelementmethode (1999)
    Springer
    Electrical engineering 82 (1999), S. 89-97 
    Details
    ISSN: 1432-0487
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Description / Table of Contents: Contents It is possible to calculate the leakage inductances of power transformers from their blueprints by using the boundary element method. Empirical values are not needed. The resulting dense systems of linear equations with up to 100,000 unknown variables can be solved by using block matrices. Since it is possible to describe the greatest part of all windings of power transformers, the calculated leakage inductances differ only less than two and a half percent from measured values by the manufacturer.
    Notes: Übersicht Mit der Randelementmethode ist die Berechnung der Streuinduktivitäten von Leistungstransformatoren allein aus ihren Konstruktionsdaten möglich. Es werden keine Erfahrungswerte benötigt. Durch Verwendung eines Blockmatrix-Algorithmus können die dabei entstehenden dicht besetzten linearen Gleichungssysteme mit bis zu 100,000 Unbekannten gelöst werden. Damit ist es möglich, einen großen Teil der Windungen von Leistungstransformatoren zu modellieren. Die so berechneten Streuinduktivitäten weichen bei Normalausführungen um weniger als zweieinhalb Prozent von Meßwerten des Herstellers ab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002020050080
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Lymphknotendissektionen beim malignen Melanom (1996)
    Springer
    Der Chirurg 67 (1996), S. 779-787 
    Details
    ISSN: 1433-0385
    Keywords: Key words: Malignant melanoma ; Lymph node metastases ; Lymph node dissection ; Prognosis. ; Schlüsselwörter: Malignes Melanom ; Lymphknotenmetastasierung ; Lymphknotendissektion ; Prognose.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung. Die Indikation zur elektiven Lymphknotendissektion, ihre evtl. zukünftige Bedeutung als Stagingmaßnahme vor adjuvanten Therapieverfahren, die Prognose der therapeutischen Dissektion sowie die Identifizierung des Pförtner-Lymphknotens und die daraus sich ergebenden therapeutischen Konsequenzen sind die wichtigsten Aspekte der Lymphknotendissektion beim malignen Melanom. Die Indikation zur elektiven Dissektion orientiert sich nicht nur an der pT-Kategorie, sondern auch an der Tumorlokalisation, dem Tumortyp und dem Geschlecht des Patienten. Ein allgemein akzeptierter Konsens zur Auswahl der in Frage kommenden Patienten besteht noch nicht. Da die ersten Studien mit Chemo-/Immuntherapie bei nodal positiven Patienten eine Prognoseverbesserung zeigen, muß zukünftig auch die Lymphknotendissektion als Stagingmaßnahme diskutiert werden. Neue Anregungen wurden in den letzten Jahren durch die Identifikation des Pförtner(„sentinel“)-Lymphknotens eingebracht. Diese Methodik bedarf noch der weiteren Evaluierung, dürfte aber zukünftig einen wesentlichen Einfluß auf die Indikation zur elektiven Lymphknotendissektion nehmen. Mit eingetretener Lymphknotenmetastasierung verschlechtert sich die Prognose des malignen Melanoms global um 20–50 %, abhängig vom Ausmaß der Metastasierung. Die Thematik wird anhand der eigenen Ergebnisse diskutiert.
    Notes: Summary. Elective lymph node dissection and its potential as a staging procedure, the prognosis of established lymph node metastases and the sentinel lymph node identification procedure are the most important aspects of lymph node dissection in malignant melanoma. It is widely accepted that subgroups of patients benefit from elective lymph node dissection. The question of which parameters identify the relevant patients properly is still under discussion. pT-categories are the most important prognostic factor; however, localisation and type of tumour and the sex of the patients are additional parameters influencing patient selection. Recently, the first studies have identified subgroups of nodal positive patients who would profit from adjuvant chemo-/immunotherapy. Therefore, lymph node dissection as a staging procedure has to be discussed in the future. Identification of the sentinel lymph node is receiving increasing attention because of its potential influence on the reassessment of elective lymph node dissection. However, this method needs further evaluation. If lymph node metastases have occurred, the prognosis of malignant melanoma decreases by 20 %–50 %, depending on the extent of metastasis in the individual case. The relevant topics and results are discussed on the basis of data of the Surgical Department of the University Hospital of Erlangen-Nuremberg.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00002518
    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...