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
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 66 (1995), S. 727-729 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Literature data on negative photoconductivity in GaAs/AlGaAs modulation doped heterojunctions and InAs/AlGaSb undoped quantum wells are explained in terms of electron–hole pair generation in the large gap layer, with subsequent charge separation and majority carrier annihilation in the well. This effect can be classified in two different limits, depending on the position of the quasi-Fermi level μ in the large gap layer. The limit with μ on the conduction band corresponds to the GaAs/AsGaAs heterostructures, and we are able to reproduce quantitatively the available experimental results. We also show that the limit with μ on the middle of the gap corresponds to the InAs/AlGaSb heterostructures. © 1995 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
    Oxford, UK : Blackwell Publishing Ltd
    International journal of food science & technology 25 (1990), S. 0 
    ISSN: 1365-2621
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Treatments with 20% CO2 of tomato fruit produced a beneficial extension of storage life. The diffusion of CO2 in tomato (Lycopersicon esculentum Mill) cv. Platense was measured chromatographically and the concentration profiles in the internal gaseous atmosphere of the fruit were determined for non-steady state conditions to establish minimum treatment times that can ensure adequate penetration of the gas.The effective diffusivity of CO2 in the tissue was determined by fitting concentration data, obtained from experiments with whole fruit without skin, to the non-steady state solution of the diffusion equation, assuming negligible external mass transfer resistance. The diffusivity was modelled using Maxwell-Eucken expressions, taking account of the heterogeneous structure of the tissue.The resistance of the fruit skin was evaluated using whole fruits with the stem scar covered with paraffin and fitting experimental data to the solution in terms of mass Biot number; the specific resistance of the peel was some 200 times greater than that of the stem scar.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Here, we analysed the use of Vb-TCR regions by CD4? and CD8? T cells from acute and chronic chagasic patients using ¯ow cytometry. We determined the Vb expression in cells freshly isolated from patients, as well as after in vitro stimulation with antigens derived from epimastigote (EPI) or trypomastigote (TRYPO) forms of Trypanosoma cruzi. Analysis of Vb-TCR expression of T cells freshly isolated from patients showed a decrease in Vb5 expression in the CD4? T-cell population from acutely infected individuals, whereas CD4?Vb5? T cells were found to be increased in chronic patients with the cardiac, but not indeterminate, clinical form. After culturing peripheral blood mononuclear cells (PBMC) from chronic patients with EPI or TRYPO, we found that both antigenic preparations led to a preferential expansion of CD4?Vb5? T cells. EPI stimulation also led to the expansion of CD8?Vb5? T cells, whereas TRYPO led to the expansion of this cell population only if PBMC were from cardiac and not indeterminate patients. We observed that TRYPO stimulation led to an increase in the frequency of CD4?Vb17? T cells in cultures of PBMC from indeterminate patients, whereas an increase in the frequency of CD8?Vb17? T cells was found upon TRYPO stimulation of PBMC from cardiac patients. Despite this increase in the frequency of Vb17? T-cell populations upon TRYPO stimulation, the same antigenic preparation led to a much higher expansion of Vb5? T cells. These results show a differential expression of Vb5-TCR in cells freshly isolated from chagasic patients in different stages of the disease and that parasite-speci®c antigens stimulate a portion of the T-cell repertoire with preferential usage of Vb5-TCR.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science, Ltd
    Journal of oral pathology & medicine 31 (2002), S. 0 
    ISSN: 1600-0714
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background:  Beta-catenin, an E-cadherin-associated protein involved in cell–cell adhesion and signaling, has been hypothesized to translocate to the nucleus and activate transcription in several human cancers, including oral squamous cell carcinomas (OSCC).Methods:  In the present study, we analyzed the subcellular localization of beta-catenin in cultures of human oral normal and malignant (cell lines SCC15 and SCC25) keratinocytes and in 24 frozen samples of oral squamous cell carcinomas by a double-staining technique for nucleic acids and beta-catenin. Growth potential, as assessed by cell count at different time periods, was established for normal, SCC15 and SCC25 cell lines; oral squamous cell carcinomas were classified according to the histopathological and malignancy indexes.Results:  Beta-catenin localized at the plasma membrane in the normal and SCC15 cells, not in the SCC25 cells, where it localized mostly in the perinuclear and nuclear areas. In the growth assays, SCC25 cell lines proliferated faster than in normal and SCC15 cells over a period of 6 days (cell numbers were significantly different, P 〈 0.0001). Carcinoma sections showed a combination of membranous, cytoplasmic and, in few invading epithelial islands of two tumors, nuclear localization of beta-catenin.Conclusions:  In oral squamous cell carcinomas, nuclear beta-catenin staining was observed only within invading islands of two carcinomas deep in the underlying connective tissue. On the basis of this study, we conclude that intranuclear beta-catenin does not appear to be a common finding in oral squamous cell carcinomas and that a clear association between intranuclear beta-catenin and histopathological and malignancy indexes in vivo could not be established.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 63 (1998), S. 0 
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effects of atmospheric composition and temperature on quality of grated beetroots were analyzed. Beetroots (Beta vulgaris L.) were washed, grated and packaged in trays wrapped with two films of different gas permeabilities. Trays were stored at 0°C or 4°C for a week and then transferred to 20°C. Changes in atmospheric composition, pigment content, pH, titratable acidity and production of exudate were monitored. Shelf-life of grated beetroots was 7 d at 0°C and 3 to 4 d at 4°C. There was a notable decrease in pigment content during storage.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1365-3059
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Journal of the European Academy of Dermatology and Venereology 18 (2004), S. 0 
    ISSN: 1468-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Delayed reactions caused by red tattoo pigments are often difficult to treat. We report a 31-year-old female patient with a lichenoid reaction to a red tattoo on the right ankle who was successfully treated with five sessions of a surgical Erbium:Yag laser, using several passes in each session. Our work leads us to consider that Er:Yag laser therapy may be an effective and safe treatment for these therapeutically challenging reactions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Solid State Communications 10 (1972), S. 1075-1077 
    ISSN: 0038-1098
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Solid State Communications 19 (1976), S. 491-494 
    ISSN: 0038-1098
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Solid State Communications 11 (1972), S. 1053-1055 
    ISSN: 0038-1098
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    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...