全文获取类型
收费全文 | 251篇 |
免费 | 28篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 17篇 |
2014年 | 18篇 |
2013年 | 15篇 |
2012年 | 23篇 |
2011年 | 24篇 |
2010年 | 6篇 |
2009年 | 5篇 |
2008年 | 11篇 |
2007年 | 13篇 |
2006年 | 14篇 |
2005年 | 6篇 |
2004年 | 14篇 |
2003年 | 11篇 |
2002年 | 16篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有279条查询结果,搜索用时 15 毫秒
1.
D M Strong F Pandolfi R B Slease J E Budd J N Woody 《Journal of immunology (Baltimore, Md. : 1950)》1981,126(6):2205-2208
In a previous report, peripheral blood mononuclear T cells from a patient with T-chronic lymphocytic leukemia (T-CLL) were shown to bear receptors for the Fc portion of IgG (T gamma). Moreover, the ability of these cells to rosette with sheep erythrocytes was strongly inhibited by a preincubation of the cells with theophylline. These data indicated that they represent a highly purified subpopulation of Fc-IgG receptor-positive, low-affinity rosetting cells with in vitro suppressor activity on lectin-induced proliferation of normal lymphocytes. They also were reactive in antibody-dependent cell-mediated cytotoxicity but had no reactivity in natural killer cell assays. These cells were studied in this report with several heteroantisera and monoclonal antibodies. Results indicate that these T-CLL cells express a T cell antigenic pattern (OKT-3+) and the majority are Ia positive. They also react with the OKT-8 reagent (a reagent detecting the subset of T cells that contains the cytotoxic/suppressor cells), whereas they are negative with OKT-4 (which reacts with the subset of T cells that contains helper cells) and OKT-6 (thymocyte) antibodies. Heteroantisera also support the results obtained with monoclonal reagents. Despite some recent evidence showing that a high percentage of T gamma cells may belong to the monocyte-myeloid lineage, these T-CLL cells were negative with OKM-1, a monoclonal antibody reported to detect a monomyeloid antigen. These results suggest that a distinct subpopulation of suppressor T cells can be identified by membrane-marker phenotyping. 相似文献
2.
Franco Pandolfi Douglas M. Strong Guy D. Bonnard Ronald B. Herberman 《In vitro cellular & developmental biology. Plant》1980,16(9):754-760
Summary Four hematopoietic cell lines (CCRF-CEM, HSB-2, MOLT-4, and RPMI-8402), derived from acute lymphoblastic leukemia and expressing
T-cell surface markers (T-HCL), were studied with two specific anti-T-cell sera. The sera were raised in rabbits against human
thymocytes (anti-HTY) and against T-cells cultured in the presence of conditioned medium derived from lymphocytes stimulated
with PHA (anti-CTC). Both sera were absorbed to obtain a T-cell specific pattern of reaction and were further absorbed with
normal peripheral blood lymphocytes or with each of the four T-HCL. The anti-HTY sera absorbed with CEM, 8402, and HSB-2 still
reacted with MOLT-4. A similar pattern of reactivity was found only with the anti-CTC absorbed with 8402, whereas, after absorptions
with the other cell lines, this antiserum was unreactive against MOLT-4. After absorption with normal peripheral blood lymphocytes,
anti-HTY still reacted with thymocytes and MOLT-4 but was negative on CTC. In contrast, anti-CTC absorbed with peripheral
blood lymphocytes (PBL) was negative on thymocytes and MOLT-4 but still reacted against CTC. Our data confirm the existence
of a T-cell antigen (probably an early T-cell differentiation antigen) shared between thymus and MOLT-4. This antigen is not
expressed on CTC, although these cells express an antigenic pattern more complex than PBL. Antisera to CTC represents a source
of anti-T-cell sera free of contamination with antibodies to early thymus-related antigens but containing other T-cell-related
specificities.
Supported in part by Naval Medical Research and Development Command, Research Task No. ZF51.524.013.1025, and National Cancer
Institute Contract No. Y01-CB-00319. The opinions and assertions contained herein are the private ones of the writers and
are not to be construed as official or reflecting the views of the Navy Department or the naval service at large. The experiments
reported herein were conducted according to the principles set forth in the current edition of the “Guide for the Care and
Use of Laboratory Animals,” Institute of Laboratory Animal Resources, National Research Council. 相似文献
3.
4.
5.
6.
Diabetes is associated with accelerated atherosclerosis and macrovascular complications are a major cause of morbidity and mortality in this disease. Although our understanding of vascular pathology has lately greatly improved, the mechanism(s) underlying enhanced atherosclerosis in diabetes remain unclear. Endothelial cell dysfunction is emerging as a key component in the pathophysiology of cardiovascular abnormalities associated with diabetes. Although it has been established that endothelium plays a critical role in overall homeostasis of the vessels, vascular smooth muscle cells (vSMC) in the arterial intima have a relevant part in the development of atherosclerosis in diabetes. However, high glucose induced alterations in vSMC behaviour are not fully characterized. Several studies have reported that impaired nitric oxide (NO) synthesis and/or actions are often present in diabetes and endothelial dysfunction. Furthermore, although endothelial cells are by far the main site of vascular NO synthesis, vSMC do express nitric oxyde synthases (NOSs) and NO synthesis in vSMC might be important in vessel's function. Although it is known that vSMC contribute to vascular pathology in diabetes by their change from a quiescent state to an activated proliferative and migratory phenotype (termed phenotypic modulation), whether this altered phenotypic modulation might also involve alterations in the nitrergic systems is still controversial. Our recent data indicate that, in vivo, chronic hyperglycemia might induce an increased number of vSMC proliferative clones which persist in culture and are associated with increased eNOS expression and activity. However, upregulation of eNOS and increased NO synthesis occur in the presence of a marked concomitant increase of O(2-) production. Since NO bioavailabilty might not be increased in high glucose stimulated vSMC, it is tempting to hypothesize that the proliferative phenotype observed in cells from diabetic rats is associated with a redox imbalance responsible quenching and/or trapping of NO, with the consequent loss of its biological activity. This might provide new insight on the mechanisms responsible for accelerated atherosclerosis in diabetes. 相似文献
7.
Kurnick JT Ramirez-Montagut T Boyle LA Andrews DM Pandolfi F Durda PJ Butera D Dunn IS Benson EM Gobin SJ van den Elsen PJ 《Journal of immunology (Baltimore, Md. : 1950)》2001,167(3):1204-1211
We have observed that malignant melanoma cells produce a soluble protein factor(s), which down-regulates melanocyte lineage Melan-A/MART-1 Ag expression by melanoma cells with concomitant loss of recognition by Melan-A/MART-1-specific T cells. This down-modulation of Melan-A/MART-1 expression, which we refer to as "Ag silencing," is mediated via its minimal promoter, whereas the promoter for the restricting Ag-presenting HLA-A2 molecule is not affected. Significantly, this Ag silencing is reversible, as removal of factor-containing supernatants from Melan-A/MART-1-expressing cells results in up-regulation of the promoter for the gene encoding this Ag, and renewed expression of the protein. We have evaluated over 20 known factors, none of which accounts for the Ag-silencing activity of the melanoma cell culture supernatants. The existence of this autocrine pathway provides an additional novel explanation for melanoma tumor progression in vivo in the presence of CTL specific for this melanocyte lineage Ag. These observations may have important implications for Melan-A/MART-1-specific CTL-mediated immunotherapy of melanoma tumors. 相似文献
8.
9.
Gram-staining characterisation of activated sludge filamentous bacteria by automated colour analysis
An automated image analysis method has been developed for the monitoring of the Gram-staining characteristics of filamentous bacteria in activated sludge. The binary method of pixel classification agreed with manual estimation (level of correlation of 0.9 for Gram-positive bacteria). Its robustness has been assessed by repeatability tests. Population shifts in terms of Gram-staining characteristics have been monitored in laboratory-scale experiments with two feeding schedules using this technique.Revisions requested 22 September 2004; Revisions received 11 October 2004 相似文献
10.
In Alpine Corsica, the Balagne Nappe displays the best-developed sedimentary succession associated with an ophiolite sequence. This sedimentary succession includes the Alturaia Arkose, whose age is still unknown. Several shale horizons cropping out in the Cima di Alturaia area were studied for palynological analyses. In this paper, a new palaeontological find in the Alturaia Arkose is reported and the related geological implications are discussed. The collected data indicate the occurrence of a palynological assemblage of Late Barremian to Middle Aptian age. The Alturaia Arkose can be regarded as a clastic deposit of Late Barremian–Middle Aptian age derived from rocks cropping out in Hercynian Corsica. To cite this article: M. Marroni et al., C. R. Palevol 3 (2004).