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
Filter
  • Articles: DFG German National Licenses  (15)
  • 2005-2009
  • 1990-1994  (15)
  • 1994  (15)
  • 1
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 65 (1994), S. 2925-2927 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: When illuminated with a focused beam from He-Ne lasers, As2S3 films with thickness of ∼50 μm exhibit the thickness expansion reaching to 3 μm, which is approximately 10 times as great as that expected from the conventional photoexpansion phenomenon. The enhancement seems to be caused by photorelaxation of strain generated by photoexpansion. © 1994 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 64 (1994), S. 1771-1773 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Bragg reflectors have been fabricated in As2S3 glasses through the photoinduced refractive-index change process. Illumination of single monochromatic beams can produce Bragg reflectors with a half Bragg width of 2 nm in wavelength and the reflectivity estimated from the transmission decrease at 10%–20%. The reflectors can be erased with annealing and polychromatic illumination.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 49 (1994), S. 0 
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: To determine whether the response to the active complement fragment C5a in polymorphonuclear leukocytes (PMN) obtained from a patient with Kimura's disease is similar to that in normal subjects, we evaluated superoxide anion (O2-) generation after stimulation with C5a. The patient's PMN produced more O2- than did those from healthy controls after stimulation with human C5a in vitro. The response returned to normal with the improvement in clinical indicators after initiation of steroid administration. We conducted the following experiments with the plasma of this patient during the active disease stage to establish the presence of a humoral factor that potentiated the C5a-response of PMN. Incubation of PMN from normal controls having the same blood type as the patient at 37°C for 2 h with the patient's plasma at the active disease stage revealed that the cells generated abundant O2- after stimulation with C5a. Incubation of normal PMN with the patient's plasma during the inactive disease stage showed no potentiated response to C5a. This activity was lost after incubation at 56°C for 30 min. Coincubation of PMN with methylprednisolone up to 100 μg/ml did not suppress this activity. Although the plasma concentration of C5a at the active stage was mildly elevated (13 ng/ml), it was below the limit of detection (〈10 ng/ml) at the inactive stage. These results suggest the presence of a heat-labile, humoral factor in the patient's plasma that upregulated the response of PMN to C5a and that was not suppressed by in vitro treatment with a steroid. This factor may influence the acute inflammatory reaction in this disorder.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The expression regulation of spvR, a regulatory gene on the virulence plasmid (pKDSC50) of Salmonella choleraesuis serovar Choleraesuis, was investigated by spvR–lacZ translational fusion. The spvR gene was found to be positively regulated by its own product, the SpvR protein, and this unusual positive auto-regulation was repressed by the products of spvA and spvB, virulence-associated genes present downstream from the spvR gene. Amino acid sequence analysis revealed that the amino-terminal region of SpvB had homology with the CatM repressor protein of Acineto-bacter calcoaceticus, which belongs to the MetR/LysR protein family. On the other hand, the sigma factor RpoS was required for expression of the spvR gene in the stationary phase of bacterial growth. The SpvR protein was also necessary for self-activation, suggesting that an RNA polymerase holoenzyme containing RpoS requires SpvR protein in order to recognize the spvR promoter.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-5195
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Afin d'étudier la prolifération in vitro des cellules tumorales malignes des os et des tissus mous, nous avons utilisé des molécules reconstituées de la membrane basale organisées en barrières. Un grand nombre de cellules provenant de tumeurs malignes humaines ont montré un taux élevé de prolifération bien que les fibroblastes n'aient fait preuve d'aucune aptitude à franchir la barrière de la membrane basale. Dans les fibroblastes les cellules infectées par le H-ras oncogène ont proliféré beaucoup plus que les rangées apparentées. Les cultures primaires de cellules tumorales malignes ont montré cette prolifération, contrairement aux cellules non-métastatiques et aux fibroblastes. On a constaté que la liaison dans la membrane basale des cellules tumorales à la laminine déclenche la sécrétion de collagènase IV et la motilité, qui sont considérées comme les deux facteurs cruciaux de la prolifération. Nous avons réalisé ces études de la prolifération dans le but de tester les facteurs susceptibles de l'entraver. Un peptide synthétique, le Tyr-Ile-Gly-Ser-Arg (YIGSR), de la chaîne B1 de la laminine s'est montré capable d'arrêter la prolifération des cellules du sarcome humain HT1080, l'YIGSR peut également réduire in vivo l'envahissement du poumon. Ces résultats permettent de penser que ces expériences sont utiles, essentiellement pour déterminer le potentiel de prolifération, ensuite pour préciser le mécanisme de l'envahissement et enfin pour mettre au point des thérapeutiques efficaces contre la prolifération et les métastases des tumeurs malignes des os et des tissus mous.
    Notes: Summary We have used reconstituted basement membrane molecules which have formed into barriers in order to investigate the invasive potential of malignant bone and soft tissue tumour cells in vitro. A number of cell lines established from human malignant tumours demonstrated a high degree of invasiveness, although fibroblasts showed no ability to penetrate the basement membrane barrier. H-ras oncogene transfected cells into the fibroblasts were much more invasive than the parent lines. Primary cultures of malignant tumour cells demonstrated invasiveness, while those of nonmetastatic cells and fibroblasts did not. The binding of tumour cells to laminin in the basement membranes was found to induce secretion of collagenase and motility which are crucial factors for invasion. A synthetic peptide, Tyr-Ile-Gly-Ser-Arg, was able to suppress the invasiveness of HT1080 human fibrosarcoma cells, and also reduced lung colonisation in vitro. The results suggest that the in vitro assay was useful, firstly to determine the invasive potential, secondly to investigate the mechanism of invasion, and finally to development treatment against invasion and metastases.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-2307
    Keywords: Insulin-like growth factor II ; Hypoglycaemia ; Gastric cancer ; Non-islet cell tumour hypoglycaemia ; Insulin receptor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A gastric cancer with liver metastases was associated with low morning levels of plasma glucose (24 mg/dl), insulin (〈2.5 μU/ml) and growth hormone (0.23 ng/ml). Primary and metastatic tumour tissue stained positively with anti-insulin-like growth factor II(IGF-II) monoclonal antibody. Western immunoblot analysis revealed a high molecular weight IGF-II in the serum: 15 kDa (normal: 7.5 kDa). Postmortem reverse transcription polymerase chain reaction on mRNA from both sites revealed 471 base pairs size cDNA encoding prepro-IGF-II. These results suggest that the gastric carcinoma encoded, expressed, and secreted IGF-II, probably causing the extrapancreatic tumour hypoglycaemia.
    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. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 175-178 (Nov. 1994), p. 789-792 
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    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.] : International Union of Crystallography (IUCr)
    Acta crystallographica 50 (1994), S. 246-252 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Accurate X-ray intensities of a PtP2 crystal were measured with the multiple-diffraction effect avoided by using the ψ rotation of the crystal around the scattering vector. The results were compared with those of a measurement made without avoiding the effect. The extinction parameters were more isotropic and the peaks of the deformation density were significantly smaller when multiple diffraction was avoided. In the measurement made without avoiding the effect, the number of structure factors affected by more than 1% was 403 from 936 reflections measured. Of 272 strong reflections with sin &thgr;/λ 〈 0.6 Å−1 and Fobs 〉 200, 27 reflections were affected by more than 1%. These facts, as well as the smaller R values, indicate that the multiple-diffraction effect cannot be neglected in electron-density studies of crystals including heavy atoms. To assess the intensity fluctuation calculated in the present study, the intensities of 200 reflections were measured at intervals of 0.5° from 0 to 180° in ψ and compared with the calculated values. The variations of the measured and calculated intensities with ψ correspond to each other, which indicates that the present method can be used effectively to identify the reflections affected significantly by multiple diffraction.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0942-0940
    Keywords: Cytoskeleton ; delayed neuronal death ; nerve growth factor (NGF) ; neurofilament (NF)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We investigated the protective action of nerve growth factor (NGF) on delayed neuronal death, and we also studied the involvement of the 200 kDa neurofilament (NF 200) cytoskeletal proteins. Wistar rats were divided into three groups: Group I, in which transient forebrain ischaemia was produced; Group II, ischaemic group which received intraventricular administration of artificial cerebrospinal fluid (CSF); and Group III, ischaemic group which received intraventricular administration of 2 Μg of 2.5 S NGF. Forebrain ischaemia in these rats was produced by causing transient bilateral occlusion of the common carotid arteries and lowering the mean blood pressure to 50 mmHg for 8 minutes. On the 1st and 7th day after ischaemia we histologically examined neuronal death in the hippocampal CA1 sector. On the 7th day after ischaemia, mean cell death (degenerative cell number/total cell number) was 87±9% in group I (n=7), 51±36% in group II (n=7), and 14±16% in group III (n=8) (p〈0.05 vs. group II). The concentration of NF 200 in the hippocampal homogenate was measured by the Western blotting method on the 1st and 7th day after ischaemia. On the 1st day it was found to be 67±11% of that in the control group in group I (n=6), 73±21% in group II (n=6), and 84±7% in group III (n=6) (p〈0.05 vs. group II). The concentration of NF 200 in all groups remained at the same level until the 7th day after ischaemia (each group, n=6). These results suggest that 1) intraventricular NGF has a protective effect on delayed neuronal death, 2) these protective actions occur within one day after ischaemia, and 3) these effects may be mediated by the suppressed degradation and/or promoted restoration of neuronal cytoskeletal proteins.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1435-1536
    Keywords: Cationic azo-surfactant ; photoisomerization ; electric conductivity ; micelle formation ; aggregation mode
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The cationic azo-surfactants possessing different spacers and tail alkyl chain lengths have been synthesized by azocoupling ofp-alkylaniline orop-ethoxyaniline with phenol, followed by alkylation and quaternalization with dibromoalkane and trimethylamine, respectively. These surfactants showed a good solubility in water. A reversibletrans-cis isomerization of the azosurfactants by photoirradiation was assessed by UV-Vis absorption spectra. Due to a difference in HLB between thetrans- andcis-surfactants, the observed critical micelle concentration (CMC) values and the electric conductivity of the surfactant solution at above the CMC were significantly affected by the photoinducedtrans-cis isomerization. The azo-surfactants bearing moderate alkyl chain lengths such as surfactants 6 (R2=C2H4, R3=C4H9) and 9 (R2=C4H8, R3=C2H5) were found to be effective to achieve large CMC changes (3.6 mmol/L for 6 and 5.9 mmol/L for 9) by UV-light irradiation. The replacement of the tail chain species also affected the photoresponsive function. The surfactant 12, possessingp-ethoxy group as the tail chain, was found to form a stable micelle aggregation as compared with the structurally related surfactant 10 having ethyl unit as its tail group, but it exhibited a large CMC change (5.3 mmol/L) by UV-light irradiation.
    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...