首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   25篇
  免费   1篇
  2017年   1篇
  2016年   1篇
  2014年   1篇
  2013年   1篇
  2011年   2篇
  2006年   2篇
  2004年   2篇
  2003年   3篇
  2002年   1篇
  2001年   1篇
  2000年   1篇
  1985年   1篇
  1984年   3篇
  1967年   2篇
  1957年   1篇
  1955年   2篇
  1954年   1篇
排序方式: 共有26条查询结果,搜索用时 15 毫秒
1.
This report describes the use of an anthraquinone mediated fuel cell for the direct production of electrical energy from sulfonated lignin and Kraft Black Liquor. The cell produces the equivalent of 1 kWh for each 2-3 lb sulfonated lignin and 5-8 lb black liquor combustibles. In the case of the sulfonated lignin, chain session occurs during the oxidation process, reducing the molecular weight from ca. 2 x 10(4) to less than 1000 D.  相似文献   
2.
Pemphigus is an autoimmune disease in which IgG auto-antibodies (auto-ab) against the desmosomal cadherins desmoglein (Dsg) 3 and Dsg1 cause loss of epidermal keratinocyte adhesion. Aim of this study was to investigate cytokines derived from antigen-presenting cells (APC) and their relation to CD4+ T cell subpopulations and to the auto-ab response in pemphigus. In this regard, patients with pemphigus were compared to patients with myasthenia gravis (MG), an unrelated auto-ab–mediated autoimmune disease, and healthy controls. In pemphigus and MG, the plasma concentrations of the APC-derived immunomodulatory cytokine IL-27 were highly increased. Strikingly, IL-27 strongly correlated with Dsg-specific IgG auto-ab titers. T helper (Th) 17 cells were augmented in both pemphigus and MG patients while T follicular helper (Tfh) cells, which are essential in providing B cell help, were increased only in pemphigus along with increasing plasma concentrations of IL-21, a cytokine produced by Th17 and Tfh cells. Moreover, we could detect Dsg3-specific autoreactive T cells producing IL-21 upon ex vivo stimulation with Dsg3. These findings suggest that IL-27 and IL-21-producing T cells, are involved in the pathogenesis of pemphigus. The further characterization of IL-21-producing T cells and of the role of IL-27 will lead to a more defined understanding of the auto-ab response in pemphigus.  相似文献   
3.
Pemphigus vulgaris (PV) is the most severe autoimmune bullous skin disorder and is primarily associated with circulating autoantibodies (autoAb) against desmoglein 3 (Dsg3). In light of recent evidence that autoreactive T cells are critical for the induction and regulation of Ab production, the goal of this study was to characterize and quantitate autoreactive T cells in patients with PV and healthy controls. Peripheral Dsg3-reactive Th cells from 28 patients with acute-onset, chronic active, and remittent PV were quantitated by MACS secretion assay. Dsg3-reactive Th2 cells were detected at similar frequencies in all studied PV patients, while the number of autoreactive Th1 cells exceeded those of Th2 cells in chronic active PV. In contrast, healthy carriers of the PV-associated HLA class II alleles, DRB1*0402 and DQB1*0503, exhibited exclusively Dsg3-reactive Th1 cell responses, while healthy carriers of other HLA class II alleles did not. Moreover, the presence of IgG1 and IgG4 against Dsg3 was directly related to the ratio of Dsg3-reactive Th1/Th2 cells. T cell recognition of Dsg3 was restricted by HLA-DRB1*0402 and DQB1*0503 in PV patients and Dsg3-responsive healthy donors. These observations strongly suggest 1) that the appearance of Dsg3-reactive Th2 cells is restricted to patients with PV; 2) that specific HLA class II alleles that are prevalent in PV are critical for T cell recognition of Dsg3 in PV patients and Dsg3-responsive healthy donors; and 3) that autoAb production is associated with both Th1 and Th2 cells.  相似文献   
4.
Pemphigus vulgaris (PV) is a severe autoimmune bullous skin disorder and is primarily associated with circulating autoantibodies against desmoglein 3 (Dsg3) that are presumably regulated by Th cells. The aim of this study was to identify Dsg3-specific T regulatory (Tr) cells that may help to maintain and restore natural tolerance against Dsg3. Dsg3-responsive IL-10-secreting Tr1 cells were isolated by MACS cytokine secretion assay from healthy carriers of the PV-associated HLA class II alleles, DRB1*0402 and DQB1*0503, but were only rarely detected in PV patients. The Dsg3-specific Tr1 cells secreted IL-10, TGF-beta, and IL-5 upon Ag stimulation, proliferated in response to IL-2 but not to Dsg3 or mitogenic stimuli, and inhibited the proliferative response of Dsg3- and tetanus toxoid-responsive Th clones in an Ag-specific (Dsg3) and cell number-dependent manner. Moreover, their inhibitory effect was blocked by Ab against IL-10, TGF-beta, and by paraformaldehyde fixation. These observations strongly suggest that 1) Dsg3-responsive Tr1 cells predominate in healthy individuals, 2) their growth requires the presence of IL-2, and 3) they exert their Dsg3-dependent inhibitory function by the secretion of IL-10 and TGF-beta. Because autoaggressive T cells responsive to identical epitopes of Dsg3 were recently found both in PV patients and healthy individuals, the identified Tr1 cells may be critically involved in the maintenance and restoration of tolerance against Dsg3.  相似文献   
5.
6.
Nickel (Ni) is one of the most common contact sensitizers in man, and Ni-induced contact dermatitis is considered as a model of hapten-induced delayed type hypersensitivity. Previous studies indicated that Ni-reactive T cells derived from Ni-allergic individuals preferentially express distinct TCR-Vbeta chains. However, data on the TCR-Vbeta repertoire of Ni-responsive T cells are not consistent. Therefore, the aim of this study was to identify the TCR-Vbeta receptors of Ni-responsive peripheral and cutaneous T cells in a cohort of 17 donors with Ni-induced contact dermatitis in comparison with those of 6 healthy controls. Peripheral NiSO(4)-responsive T lymphocytes showed a significant overexpression of TCR-Vbeta17 and the frequency of TCR-Vbeta17(+) T cells correlated significantly with the in vitro reactivity of PBMC to NiSO(4). In addition, the cutaneous infiltrate of Ni-induced patch test reactions consisted primarily of Vbeta17(+) T cells. The majority of patch test-derived NiSO(4)-responsive T cells of three allergic donors were TCR-Vbeta17(+), whereas patch test-derived NiSO(4) unresponsive T cells of four additional donors did not express TCR-Vbeta17. Skin-derived Ni-responsive T cell lines from three donors uniformly secreted the Th2 cytokine, IL-5, but no IFN-gamma or IL-10. These in vitro and in vivo findings strongly suggest that T cells with a restricted TCR-Vbeta repertoire, i.e., Vbeta17, predominate in NiSO(4)-induced contact dermatitis and may be crucial in the effector phase of Ni hypersensitivity.  相似文献   
7.
Bullous pemphigoid (BP) is a well-characterized model of autoantibody-mediated autoimmunity, which presumably depends on autoreactive Th cells that promote the activation of autoreactive B cells. The two major autoantigens of BP are BP180 and BP230, two components of dermoepidermal adhesion complexes. Both, autoreactive Th cell responses and autoantibody profiles were characterized in 35 patients with acute onset BP using BP180 and BP230 proteins. Our findings indicate the following: 1) autoreactive Th cells recognized epitopes within the NH2-terminal (77.1%), COOH-terminal (65.7%), and central portion (57.1%) of the BP180 ectodomain; 2) IgG autoantibodies were found to exhibit similar or identical reactivity against the NH2-terminal (82.8%), COOH-terminal (77.1%), and central portion (37.1%) of the BP180 ectodomain; 3) T and B cell reactivity with the NH2-terminal portion of the BP180 ectodomain was associated with extensive BP, whereas the central portion was more frequently recognized in limited BP; 4) only 7 of 16 (43.7%) and 6 of 16 (37.5%) BP patients showed a Th cellular response against the COOH- and NH2-terminal regions of BP230, respectively, whereas 5) IgG reactivity against the COOH- and NH2-termini of BP230 was detected in 5 of 16 (31.3%) and 6 of 16 (37.5%) patients, respectively. These results demonstrate that Th and B cell reactivities against BP180, are, in contrast to BP230 reactivity, almost constantly detectable in BP patients, and differential epitope recognition of BP180 seems to be associated with distinct clinical severity. These observations support the concept that BP180, but not BP230, is the primary autoantigen of BP critical for disease development.  相似文献   
8.
In large herds, inseminators frequently thaw multiple straws of semen and prepare several insemination guns at once. The aim of this study was to measure the effect of breeding order, the order that thawed straws are used, on conception rate in commercial dairy herds. A single professional inseminator, utilizing semen from five suppliers, performed 2629 inseminations over 30 months. Up to four straws were thawed at one time with the restriction that straws were used within 20 min of thawing. Straws were thawed per supplier's recommendations, with 66.4% of the straws pocket thawed and the remainder warm-water thawed. Conception was determined by a pregnancy check at 42 days. Data were modeled by multiple logistic regression analysis, which included herd, breeding order, lactation number, times bred, month bred and year bred. Breeding order had no significant effect on the probability of conception: Cows 1-4 achieved adjusted conception rates of 0.36, 0.41, 0.37, and 0.39, respectively. Odds ratios (and 95% confidence intervals) were 1.00 (1.00-1.00), 1.22 (0.99-1.49), 1.04 (0.82-1.32), and 1.12 (0.86-1.45), respectively. Associated laboratory studies, which evaluated the effect of post-thaw holding time on percentage of sperm with progressive motility, found mean values at 20 min holding time to be largely unchanged from mean values at 5 min. Thawing temperatures were 6, and 35 degrees C and holding temperatures were 6, 22, and 35 degrees C. The length of the trial and the wide use of semen from multiple suppliers with differing thawing methods suggests that under similar conditions, a careful and experienced inseminator can thaw multiple straws of semen and prepare insemination guns sufficient to breed up to four cows within 20 min, without an adverse effect on conception.  相似文献   
9.
10.
Zusammenfassung Um näheren Einblick in die Beziehungen zwischen Hypothalamus und Genitale zu bekommen, wurden bei der Maus während verschiedener Entwicklungs- und Funktionsphasen des weiblichen Genitaltraktes die Zellkerne in 9 Arealen des Hypothalamus und Zellkerne des Epidems in Höhe des Nucleus paraventricularis gemessen. Erfaßt wurden die Kerne 4 (Nucleus supraopticus), 9 (Nucleus suprachiasmaticus), 10, 11 (Nucleus paraventricularis), 13 und 15 (subsummiert im Nucleus ventromedialis), 14, 16 (Nucleus arcuatus s. infundibularis; in einem rostralen und kaudalen Teil vermessen) und 20 in der Einteilung von Grünthal.Es gibt Areale, die während aller untersuchten Stadien keine Zellkernvolumenänderungen zeigen. In Zeiten erhöhter Leistung des Genitalstraktes schwellen immer die Zellkerne im Kern 20 am stärksten, mit Abstand auch die Zellkerne im Kern 16 (v. a. in seinem kaudalen Bereich). Während Schwangerschaft und Stillperiode vergrößern sich ferner regelmäßig, wenn auch in wechselndem Ausmaße, die Zellkerne in den Kernen 13 und 15. Ein vor der Tötung vorgenommener Vaginalabstrich führt zu Veränderungen an verschiedenen Kernen im Hypothalamus.Die Befunde machen es unter Berücksichtigung der Ergebnisse anderer Autoren (v. a. Spatz und Mitarbeiter) sicher, daß dem Hypothalamus mit bestimmten Kernen eine Bedeutung für die Regulierung der Sexualfunktionen zukommt.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号