Library

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
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Lymphocytes can be transformed in vitro into large blast like cells by antigens or allogenic cells. A similar reaction can be produced by phytohemagglutinin. This reaction can serve as a model for the capacity of lymphocytes in cellular immunreactions. In chronic lymphatic leucemia, lymphosarcomatosis, and lymphogranulomatosis significantly less transformation was found as compared with 40 normal individuals. In only 3 of 14 cases of chronic lymphatic leucemia more than 10% blasts (maximally 38%) were seen. In 3 cases of lymphosarcomatosis between 34 and 59% transformed cells were found. In 1 case of chronic lymphatic leucemia with subsequent development of an antibody-deficiency syndrom the PHA-reaction was totally absent. In 21 cases of lymphogranulomatosis of different stages the results were quite variable. The highest rates of transformation (51 and 76%) were observed in 6 patients with stage I and II of the disease, who had not received any specific therapy. In more advanced stages of Hodgkins disease, however, the PHA-transformation of lymphocytes was significantly reduced. In cell cultures of Hodgkin patients an increased frequency of macrophages was observed. It is suggested that the reduction in the transformation of lymphocytes in chronic lymphatic leucemia is due to the failure of the leukemic cell population to react to PHA, or to a delay in this reaction. In lymphogranulomatosis, however, the defect probably affects all lymphocytes and appears to be dependent on the stage of the disease and a plasmatic factor.
    Notes: Zusammenfassung Lymphocyten können durch Antigene oder allogene Zellen in vitro zu großen blastenartigen Zellen transformiert werden. Eine gleichartige Reaktion wird durch Phytohämagglutinin erzielt und kann als Modell für die Kapazität der Lymphocyten bei cellulären Immunreaktionen angesehen werden. Bei chronischer Lymphadenose, Lymphosarkomatose und Lymphogranulomatose war die Transformation, verglichen mit 40 Kontrollpersonen, deutlich geringer. Nur bei 3 von 14 Fällen chronischer Lymphadenose wurden mehr als 10% Blasten, maximal 38%, nachgewiesen. Bei 3 Fällen von Lymphosarkomatose wurden zwischen 34 und 59% transformierter Zellen gefunden; in einem Fall mit vorausgehender chronischer Lymphadenose und Antikörpermangelsyndrom blieb die PHA-Reaktion völlig aus. Uneinheitlich waren die Ergebnisse bei 21 Fällen von Lymphogranulomatose verschiedener Stadien. Die höchste Transformationsrate (zwischen 51 und 76%) wurde bei 6 Patienten des Stadiums I bzw. II beobachtet, die zudem noch keine ausgiebige differente Behandlung erhalten hatten. In fortgeschrittenen Stadien der Erkrankung war dagegen die PHA-Transformation der Lymphocyten deutlich geringer. In den Zellkulturen der Hodgkin-Patienten wurden relativ häufig und vermehrt Makrophagen nachgewiesen. Die verminderte Transformation der Lymphocyten resultiert bei der chronischen Lymphadenose vermutlich daraus, daß die leukämische Zellpopulation nicht oder sehr verzögert auf PHA reagiert, während anderseits bei der Lymphogranulomatose wahrscheinlich ein alle Lymphocyten betreffender und vom Krankheitsstadium abhängiger Defekt vorliegt.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 64 (1986), S. 451-463 
    ISSN: 1432-1106
    Keywords: EEG ; Event-related potentials ; Linguistic processing ; Spatial perception ; Hemispheric lateralization ; Source-density analysis ; Cortical localization ; Vision
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Event-related potentials (ERPs) were recorded from 40 locations, covering most of the scalp, during repeated tasks in which the observer (O) had to judge either the tense of a printed verb (V) or the symmetry of a spatial pattern (S). Stimuli were drawn at random from large ensembles. A simplified method of Laplacean analysis (MacKay 1983, 1984) allowed the corresponding source densities to be mapped at up to 28 locations, relatively free of artefacts due to eye movements or tongue movements. O signalled his judgment in each case by pressing one of two buttons on a given cue. The decision time allowed was kept short (about 1 s) but long enough for the task to be handled successfully. When stimuli ‘V’ and ‘S’ were drawn from geometrically different ensembles, the source-density distributions for the two tasks differed significantly at a number of locations. When ‘V’ and ‘S’ were drawn from a common ensemble, however, and O was instructed on each trial (in random order) to assess each stimulus as a word or as a geometrical pattern, the similarities in the source-density maps were more striking than the differences. It would seem that during sufficiently rapid verbal and spatial judgments, little sign of hemispheric specialization or task-specific differences may appear in the spatiotemporal profile of ERP source densities. More salient differences, some lateralized, appeared during the preparation interval prior to verbal and spatial tasks; but their pattern varied widely from subject to subject.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 186 (1960), S. 695-696 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] IN 1955 Hewat and Eastcott1 reported that a relationship exists between prevalence of caries and certain soil conditions in New Zealand, and a general investigation is at present being conducted to determine the causal mechanisms responsible for this relationship. One phase of this investigation ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 194 (1962), S. 456-458 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] REPORTS have previously been given of a variation in prevalence of dental caries which occurred between children resident in the adjacent towns of Hastings and Napier in Hawke's Bay, New Zealand1'2. It was suggested that the lower caries in Napier children may have been related to the consumption ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0378-1119
    Keywords: Mouse cDNA library ; nucleotide sequence
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 208 (1965), S. 806-807 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] It has been proposed that constituents of actively metabolizing herbage which predispose sheep's teeth to excessive wear appear to be: (1) enzymes (proteinases), which attack the organic bonding material of the dentine; (2) acids which chelate calcium of the apatite. By these agencies tooth ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 2616-2618 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A duoplasmatron ion source fed with nitrogen usually produces a N+ fraction of approx. 60% in dc mode. In pulsed mode, the duoplasmatron ion source turns out to be a nearly perfect source for atomic nitrogen ions with a high fraction of more than 90% in the milliampere range. This is achieved by pulsing the arc discharge and not by use of any filter magnets. Parameters of operation will be given, such as the comparatively low gas inlet pressure and the arc current, which far exceeds the arc current in dc mode.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 65 (1994), S. 1462-1464 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Slit-grid emittance measurement devices usually do not scan the beam continously but in fixed linear (x) and angular (x') steps. Thus in an emittance measurement performed with a slit-grid system, the beam is represented by a number of phase space boxes with a constant area or volume determined by the linear and angular resolution. Considering the emittance as the area in the two-dimensional subspace (x,x') covered by the beam, the quantization error and its dependence on the resolution (linear and angular) as well as the influence of the beam parameters is discussed. Measuring the very low emittance of the high efficiency source (HIEFS) proved that the quantization error can be unacceptably high ((very-much-greater-than)100%). With an optimized measuring device, the normalized emittance came down from 10−1 to 3.6×10−3 π mm mrad. Finally, a typical misleading result of an emittance measurement, caused by the quantization error, is presented.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 178 (1996), S. 159-172 
    ISSN: 1432-1351
    Keywords: Tympanic membrane ; Eardrum ; Auditory nerve ; Amphibian ; Sound localization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We investigated directionalities of eardrum vibration and auditory nerve response in anesthetized northern leopard frogs (Rana pipiens pipiens). Simultaneous measures of eardrum velocities and firing rates from 282 auditory nerve fibers were obtained in response to free-field sounds from eight directions in the horizontal plane. Sound pressure at the external surface of the ipsilateral eardrum was kept constant for each presentation direction (± 0.5 dB). Significant effects of sound direction on eardrum velocity were shown in 90% of the cases. Maximum or minimum eardrum velocity was observed more often when sounds were presented from the lateral and posterior fields, or from the anterior and contralateral fields, respectively. Firing rates of 38% of the fibers were significantly affected by sound direction and maximum or minimum firing rate was observed more frequently when sounds were delivered from the lateral fields, or from the anterior and contralateral fields, respectively. Directionality patterns of eardrum velocity and nerve firing also vary with sound frequency. Statistically significant correlation between eardrum velocity and nerve fiber firing rate was demonstrated in only 45% of the fibers, suggesting that sound transmission to the inner ear through extratympanic pathways plays a non-trivial role in the genesis of directionality of auditory nerve responses.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The phthaloylation of partially substituted cellulose acetates by phthalic anhydride in acetone as the reaction medium was investigated. Special consideration is given to the influence of the original acetyl content and of the acylation catalyst on the course of reaction, as well as to the relations between course of reaction, phthaloyl-DS, and solubility of the products. The decrease in acetyl group content after phthaloylation is considered to be mainly due to splittingoff of acetyl groups during processing the reaction product and not to a transesterification reaction.
    Notes: Die Phthaloylierung partiell substituierter Celluloseacetate mit Phthalsäureanhydrid in Accton als Reaktionsmedium wurde untersucht. Besonders berücksichtigt werden dabei der Einfluß des Ausgangs-Acetylgehaltes und des eingesetzten Acylierungskatalysators auf den Reaktionsablauf, sowie der Zusammenhang zwischen Reaktionsablauf, Phthaloyl-DS und Löslichkeit der Produkte. Die Verringerung des Acetylgehaltes nach der Phthaloylierung wird in erster Linie auf eine Abspaltung während der Aufarbeitung und nicht auf eine Umesterung zurückgeführt.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...