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   348篇
  免费   19篇
  国内免费   2篇
儿科学   6篇
妇产科学   1篇
基础医学   54篇
口腔科学   1篇
临床医学   35篇
内科学   104篇
皮肤病学   1篇
神经病学   45篇
特种医学   15篇
外科学   34篇
综合类   1篇
预防医学   20篇
眼科学   2篇
药学   20篇
肿瘤学   30篇
  2023年   1篇
  2022年   3篇
  2021年   11篇
  2020年   11篇
  2019年   12篇
  2018年   9篇
  2017年   6篇
  2016年   1篇
  2015年   6篇
  2014年   7篇
  2013年   20篇
  2012年   19篇
  2011年   25篇
  2010年   14篇
  2009年   9篇
  2008年   21篇
  2007年   16篇
  2006年   11篇
  2005年   24篇
  2004年   14篇
  2003年   21篇
  2002年   13篇
  2001年   4篇
  2000年   4篇
  1999年   5篇
  1998年   2篇
  1997年   3篇
  1996年   3篇
  1995年   4篇
  1994年   7篇
  1993年   2篇
  1992年   6篇
  1991年   5篇
  1990年   5篇
  1989年   5篇
  1988年   7篇
  1987年   8篇
  1986年   6篇
  1985年   2篇
  1983年   1篇
  1982年   4篇
  1980年   1篇
  1979年   1篇
  1978年   5篇
  1977年   1篇
  1976年   2篇
  1975年   1篇
  1973年   1篇
排序方式: 共有369条查询结果,搜索用时 31 毫秒
1.
Phenotypic characteristics, and correlations between the expression of membrane NK-associated (NKa) determinants (CD11b, CD16, CD56 and CD57) and T cell receptor (TCR) genotypic patterns, were examined in 25 patients with persistent (greater than 6 months) expansions of CD3+WT31+NKa+ (CD8+ and CD8dim+) lymphocytes. These studies showed that distinct NKa phenotypic profiles were restricted to cases with rearranged TCR configurations and that clonal CD3+NKa+ components could be predicted in most cases by assessing relationships between membrane CD16 and CD56 expression. For all normal NKa subpopulations, there was a high correlation (P less than 0.0001; n = 31) between the expression of these two membrane determinants. Markedly increased CD16 expression by CD3+NKa+ cells, in relation to CD56 (i.e. a high CD16:CD56 ratio), was found exclusively in cases with rearranged TCR (13/16 cases); 2/3 of the remaining cases showing significantly reduced CD16:CD56 ratios and high (greater than 2.0) CD3+CD56+ absolute numbers. In contrast, 7/9 of the germline TCR cases had a normal CD16:CD56 ratio and 2/9 a decreased ratio with low (less than 1.0) CD3+CD56+ absolute numbers. A high ratio of CD16:CD56 expression by CD3+NKa+ lymphocytes was therefore informative for 82% of TCR rearrangements in this series; and analysis of CD16 and CD56 expression was predictive for germline and rearranged TCR configurations in 24/25 persistent CD3+NKa+ expansions.  相似文献   
2.
Fifty mothers and 44 well siblings of children and adolescents with cystic fibrosis (CF) participated in this study to identify correlates of maternal well-being. Participants completed postal questionnaires which assessed maternal well-being, problems experienced surrounding the illness and treatment and the nature of the sibling relationship. Due to the demanding nature of treatment and the fact that CF is both genetic and incurable at present we anticipate mothers of these children will experience higher levels of stress and consequently poorer well-being than the normal population. In addition, illness severity, problems with adherence to treatment, child communication, maternal support and the sibling relationship are expected to relate to maternal well-being. Mothers in this sample did not rate their well-being as any different to the normal population. Results suggest that mothers are likely to rate their own well-being as poor when they report more frequent problems surrounding the illness and treatment and well children rate their sibling relationship as having frequent disagreements and aggression. This study highlights factors that are related to maternal well-being in families where one child has CF. These mothers as a group do not appear to be experiencing more stress in their daily lives than the normal population but certain illness and family variables are related to their well-being when examining the mothers on certain dimensions.  相似文献   
3.
4.
5.
Regulatory T (T(reg)) cells and host antigen-presenting cells (APCs) have been implicated in graft-versus-host disease (GVHD) and the graft-versus-leukemia (GVL) effect after donor lymphocyte infusion (DLI), but their relative contributions remain unclear in early versus long-term complete donor or mixed murine allogeneic hematopoietic stem cell (HSC) chimeras. We have previously demonstrated that donor HSC-derived Thy1(+) T(reg) cells, consisting primarily of CD4(+)CD25(+) cells, play an important role in the suppression of graft-versus-host (GVH) reactivity when DLI is given to complete donor chimeras 28 days after HSC transplantation. Data presented here demonstrate that protection against GVHD exerted by Thy1(+) T(reg) cells is less evident with time and eventually is not required in long-term complete donor chimeras because of an absence of host-type APCs to activate alloreactive T cells. Lethal GVHD was observed when Thy1(+) T(reg) cells were depleted from complete donor chimeras given by DLI at day 28, 35, or 42; however, T(reg) cell depletion and DLI at day 70 no longer induced GVHD-associated mortality. Moreover, the failure of DLI to induce GVHD with T(reg) depletion correlated with a loss of the DLI-induced GVL effect in long-term (day 100) complete donor chimeras. In contrast to the results from complete donor chimeras, GVL reactivity in day 100 mixed chimeras was robust after DLI. Loss of a DLI-induced GVL effect in long-term complete donor chimeras was attributed to the absence of host APCs because the infusion of exogenous host-type dendritic cells partially restored both DLI-induced GVL and GVH reactions in day 100 complete donor chimeras. The GVL and GVH reactions restored by infusion of host dendritic cells in day 100 complete donor chimeras were at least partially regulated by T(reg) cells because transient depletion of CD25(+) cells increased both the GVL effect and the severity of GVHD after DLI. Taken together, these data suggest that T(reg) cells can regulate DLI-induced GVL and GVH reactions in both early and long-term complete donor chimeras, and a state of mixed chimerism is superior to complete donor chimerism because host-type APCs facilitate a DLI-induced GVL effect without severe GVHD.  相似文献   
6.
7.
8.
9.
Acute lymphoblastic leukaemia of B-cell phenotype (B-ALL) is uncommon. We studied eight cases of B-ALL, investigating the clinical characteristics as well as the biological features. Cytology revealed a typical L3 profile in most cases, but in one case the morphological diagnosis was L2 and morphometric analysis indicated that the blasts in B-ALL were larger than in other ALLs. Cytogenetic study detected the typical translocations (8; 14) and (8; 22) in most of the cases. Abnormalities of the long arm of the chromosome 1 were found in four cases and a major aneuploidy was observed in one case. Cell-cycle analysis showed a high degree of proliferation with, in all cases, a small fraction of cells in G1 with low protein content (corresponding to early G1). All these biological characteristics must be related to the poor prognosis of this disease.  相似文献   
10.
Diagnostic features (cytochemistry, immunophenotyping and serum biochemistry) were examined in 51 cases of acute monocytic leukaemia (AMoL). Peroxidase, Sudan black B and alpha naphthyl acetate esterase (ANAE) cytochemical reactions were unrelated to morphological (FAB groups M5a and M5b) or immunological subtype. ANAE cytochemistry, however, indicated that AMoL cases could be subdivided into those with typical (M-type) reactions and those with insignificant staining or monocytic ANAE isoenzymes (defined by IEF). All cases were phenotypically CD13/CD33 positive and, with one exception, had greater than 30% HLA-DR positive cells. Membrane CD14 expression was insignificant or variable in 33% of M5a cases in contrast to 23/24 M5b cases which showed high proportions of CD14-staining cells with at least two monoclonal antibodies. Serum lysozyme, LDH and beta-2 microglobulin (beta 2m) were increased in 88%, 68% and 81% of cases respectively but, with the exception of statistically higher lysozyme levels in CD14+ cases, were unrelated to the morphological, cytochemical or immunological diagnostic subgroups. Clinical and diagnostic features were also examined as possible prognostic indicators. The morphological, cytochemical and immunological subgroups of AMoL were not found to be of prognostic relevance but age (P = 0.004), renal failure (P = 0.005) and serum beta 2m levels (P = 0.002) were related to patient survival. Moreover, renal failure and serum beta 2m remained significant (P = 0.012 respectively) when age was taken into account and were shown to be independent prognostic variables.  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