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   2327篇
  免费   150篇
  国内免费   120篇
耳鼻咽喉   39篇
儿科学   94篇
妇产科学   60篇
基础医学   312篇
口腔科学   35篇
临床医学   261篇
内科学   634篇
皮肤病学   53篇
神经病学   68篇
特种医学   422篇
外国民族医学   1篇
外科学   139篇
综合类   63篇
一般理论   1篇
预防医学   138篇
眼科学   21篇
药学   140篇
中国医学   7篇
肿瘤学   109篇
  2023年   7篇
  2022年   8篇
  2021年   38篇
  2020年   21篇
  2019年   25篇
  2018年   32篇
  2017年   18篇
  2016年   39篇
  2015年   49篇
  2014年   42篇
  2013年   71篇
  2012年   50篇
  2011年   82篇
  2010年   79篇
  2009年   69篇
  2008年   93篇
  2007年   116篇
  2006年   90篇
  2005年   106篇
  2004年   64篇
  2003年   57篇
  2002年   51篇
  2001年   44篇
  2000年   56篇
  1999年   52篇
  1998年   108篇
  1997年   108篇
  1996年   114篇
  1995年   79篇
  1994年   67篇
  1993年   80篇
  1992年   47篇
  1991年   52篇
  1990年   43篇
  1989年   69篇
  1988年   53篇
  1987年   62篇
  1986年   39篇
  1985年   54篇
  1984年   23篇
  1983年   19篇
  1982年   27篇
  1981年   26篇
  1980年   31篇
  1979年   16篇
  1978年   13篇
  1977年   27篇
  1976年   29篇
  1975年   20篇
  1967年   7篇
排序方式: 共有2597条查询结果,搜索用时 171 毫秒
91.
Abstract

Background/Objective: To test the hypothesis that apolipoprotein E (APOE) polymorphisms are associated with outcomes after spinal cord injury (SCI).

Methods: Retrospective cohort study, from rehabilitation admission to discharge.

Participants: Convenience sample of 89 persons with cervical SCI (C3-C8) treated from 1995 through 2003. Median age was 30 years (range 14-70); 67 were male (75%) and 83 were white (93%).

Main Outcome Measures: American Spinal Injury Association (ASIA) motor and sensory scores, ASIA Impairment Scale (AIS), time from injury to rehabilitation admission, and length of stay (LOS) in rehabilitation.

Results: Subjects with an APOE s4 allele (n = 15; 17%) had significantly less motor recovery during rehabilitation than did individuals without an s4 allele (median 3.0 vs 5.5; P < 0.05) and a longer rehabilitation LOS (median 106 vs 89 days; P = 0.04), but better sensory-pinprick recovery (median 5.0 vs 2.0; P = 0.03). There were no significant differences by APOE s4 allele status in sensory-light touch recovery, likelihood of improving AIS Grade, or time from injury to rehabilitation admission.

Conclusions: APOE ε4 allele was associated with differences in neurological recovery and longer rehabilitation LOS. Genetic factors may be among the determinants of outcome after SCI and warrant further study.  相似文献   
92.
93.
Atherosclerosis is an inflammatory disease in which several chemokines are implicated. The roles of these molecules extend from the recruitment of circulating inflammatory cells to the activation of inflammatory and pro-thrombotic cascades, which ultimately leads to an atherosclerosis-related event. One of the most studied chemokines is monocyte chemoattractant protein-1 (CCL2), which has been strongly linked to atherosclerosis in both animal and human studies. The higher the expression of either the CCL2 gene or its receptor CCR-2, the higher the likelihood of developing atherosclerosis in genetically-modified animals. Conversely, the deletion of either CCL2 or its receptor is followed by a significant reduction in the development of atherosclerotic plaques. Studies in humans yield controversial results. Most of these studies linked the plasma CCL2 concentration to the occurrence of atherosclerosis or related events; however, this relationship does not seem to be independent of the classical, known risk factors. Currently, there are no suitable analytical tools to reach strong conclusions with respect to the value of plasma CCL2 concentration as a biomarker of atherosclerosis, but experimental evidence suggests that the CCL2/CCR2 pathway should be further explored as a diagnostic, prognostic and therapeutic target.  相似文献   
94.
Spain has been one of the most affected countries by the COVID‐19 outbreak. As of April 28, 2020, the number of confirmed cases is 210 773, including 102 548 patients recovered, more than 10 300 admitted to the ICU, and 23 822 deaths, with a global case fatality rate of 11.3%. From the perspective of donation and transplantation, the Spanish system first focused on safety issues, providing recommendations for donor evaluation and testing, and to rule out SARS‐CoV‐2 infection in potential recipients prior to transplantation. Since the country entered into an epidemiological scenario of sustained community transmission and saturation of intensive care, developing donation and transplantation procedures has become highly complex. Since the national state of alarm was declared in Spain on March 13, 2020, the mean number of donors has declined from 7.2 to 1.2 per day, and the mean number of transplants from 16.1 to 2.1 per day. Increased mortality on the waiting list may become a collateral damage of this terrible pandemic.  相似文献   
95.
96.
Catastrophizing has been discussed as a cognitive precursor to the emergence of posttraumatic stress disorder (PTSD) symptoms following the experience of stressful events. Implicit in cognitive models of PTSD is that treatment-related reductions in catastrophizing should yield reductions in PTSD symptoms. The tenability of this prediction has yet to be tested. The present study investigated the sequential relation between changes in a specific form of catastrophizing—symptom catastrophizing—and changes in PTSD symptom severity in a sample of 73 work-disabled individuals enrolled in a 10-week behavioral activation intervention. Measures of symptom catastrophizing and PTSD symptom severity were completed at pre-, mid-, and posttreatment assessment points. Cross-sectional analyses of pretreatment data revealed that symptom catastrophizing accounted for significant variance in PTSD symptom severity, β = .40, p < .001, sr = .28 (medium effect size), even when controlling for known correlates of symptom catastrophizing, such as pain and depression. Significant reductions in symptom catastrophizing and PTSD symptoms were observed during treatment, with large effect sizes, ds = 1.42 and 0.94, respectively, ps < .001. Cross-lagged analyses revealed that early change in symptom catastrophizing predicted later change in PTSD symptoms; early changes in PTSD symptom severity did not predict later change in symptom catastrophizing. These findings are consistent with the conceptual models that posit a causal relation between catastrophizing and PTSD symptom severity. The clinical implications of the findings are discussed.  相似文献   
97.
98.
99.
巨噬细胞迁移抑制因子最初是由于能抑制体外巨噬细胞随机迁移而被发现,现在它作为一种重要的调节因子参与一系列炎症性疾病过程.我们最近发现,巨噬细胞迁移抑制因子的缺失使一些由炎症介质诱发的白细胞-内皮细胞相互作用减弱,提示巨噬细胞迁移抑制因子在炎症反应中起作用的机制之一是促进白细胞聚集.……  相似文献   
100.
Neutrophils isolated from cancer patients treated with granulocyte colony-stimulating factor (G-CSF) express high levels of Fc gamma RI. They exhibited an efficient killing of GD2+ neuroblastoma cells in the presence of an antidisialoganglioside (GD2) mouse monoclonal antibody (MoAb; 7A4, IgG3 kappa). However, this cytotoxicity was totally blocked by human monomeric IgG. In contrast, a bispecific antibody (7A4 bis 22/MDX-260), prepared by chemically linking an F(ab') fragment of 7A4 with an F(ab') fragment of an anti-Fc gamma RI MoAb, 22, which binds outside the Fc binding domain, triggered antibody-dependent cell cytotoxicity, even when neutrophils were preincubated with human monomeric IgG. F(ab')2 22 MoAb abrogated the MDX-260 killing without affecting that of 7A4. The 3G8 MoAb, directed against the Fc gamma RIII binding site, did not inhibit the cytotoxicity induced by either antibody. Thus, these results indicate that G-CSF-activated neutrophils exert their cytotoxic effect against neuroblastoma cells through Fc gamma RI and not Fc gamma RIII, and that the saturation of the high affinity Fc gamma RI by monomeric IgG can be overcome by the use of bispecific antibodies binding epitopes outside the IgG Fc gamma RI binding site. A combined administration of such bispecific antibodies and G-CSF may be, therefore, an efficient therapeutic approach to trigger tumor lysis by cytotoxic neutrophils in vivo.  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