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   44090篇
  免费   2342篇
  国内免费   115篇
耳鼻咽喉   614篇
儿科学   852篇
妇产科学   859篇
基础医学   5632篇
口腔科学   2161篇
临床医学   3328篇
内科学   11390篇
皮肤病学   831篇
神经病学   3633篇
特种医学   816篇
外科学   5691篇
综合类   234篇
一般理论   16篇
预防医学   3965篇
眼科学   941篇
药学   3085篇
中国医学   181篇
肿瘤学   2318篇
  2024年   23篇
  2023年   284篇
  2022年   209篇
  2021年   854篇
  2020年   464篇
  2019年   958篇
  2018年   1735篇
  2017年   1085篇
  2016年   1075篇
  2015年   1342篇
  2014年   1454篇
  2013年   2102篇
  2012年   4061篇
  2011年   4133篇
  2010年   2136篇
  2009年   1530篇
  2008年   3419篇
  2007年   3507篇
  2006年   3361篇
  2005年   3260篇
  2004年   2857篇
  2003年   2592篇
  2002年   2399篇
  2001年   148篇
  2000年   130篇
  1999年   144篇
  1998年   118篇
  1997年   96篇
  1996年   102篇
  1995年   88篇
  1994年   75篇
  1993年   72篇
  1992年   59篇
  1991年   59篇
  1990年   30篇
  1989年   35篇
  1988年   21篇
  1987年   23篇
  1986年   24篇
  1985年   32篇
  1984年   43篇
  1983年   27篇
  1982年   48篇
  1981年   31篇
  1980年   41篇
  1979年   13篇
  1978年   14篇
  1976年   13篇
  1975年   16篇
  1974年   21篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  相似文献   
2.
Lasers in Medical Science - Studies reported the harmful effects of 2,4-D on body tissues, provoking changes in the anatomy and physiology of the kidneys, liver, and testicles. Thus, the objective...  相似文献   
3.
4.
5.
6.
7.
8.
9.

Objectives

To determine the incidence of incisional hernia (IH) in the extraction incision (EI) in colorectal resection for cancer. To analyze whether the location of the incision has any relationship with the incidence of hernias and whether mesh could be useful for prevention in high-risk patients.

Methods

Retrospective review of the colon and rectal surgery database from January 2015 to December 2016. Data were classified into 2 groups, transverse (TI) and midline incision (MI), and the latter was divided into 2 subgroups (mesh [MIM] and suture [MIS]). Patients were classified using the HERNIAscore. Hernias were diagnosed by clinical and/or CT examination.

Results

A total of 182 out of 210 surgical patients were included. After a median follow-up of 13.0 months, 39 IH (21.9%) were detected, 23 of which (13.4%) were in the EI; their frequency was lower in the TI group (3.4%) and in the MIM group (5.9%) than in the MIS group (29.5%; p = 0.007). The probability of developing IH in the MIS group showed an OR = 11.7 (95%CI: 3.3-42.0) compared to the TI group and 4.3 (IC 95%: 1.1-16.3) versus the MIM group.

Conclusions

The location of the incision is relevant to avoid incisional hernias. Transverse incisions should be used as the first option. When a midline incision is needed, a prophylactic mesh could be considered in high risk patients because it is safe and associated with low morbidity.  相似文献   
10.
Food-grade titanium dioxide (E171) is widely used as a food additive, and it is known that after oral consumption, E171 is translocated into the bloodstream reaching the highest titanium level at 6 h. E171 is accumulated in some organs triggering toxicity, but the effects on the blood parameters after oral consumption have been less studied. Recently, evidence shows that oral exposure to E171 induces behavioral signs of anxiety and depression. The relation between blood alterations and psychiatric disorders has been previously demonstrated. However, the oral exposure to E171 effects on alterations in blood parameters and effects linked to alterations in animal behavior has not been explored. In this short communication, we aimed to investigate the effects of E171 on specific blood parameters (hematocrit, hemoglobin, number of erythrocytes, and leukocytes) and anxiety and compulsive-like behavior in males and females orally exposed to ~5 mg/kg for 4 weeks. The results showed that E171 decreased hematocrit and hemoglobin in male but not in female mice while leukocyte and erythrocyte count remained unaltered. Oral consumption of E171 decreased the levels of anxiety-like behavior in females but not in male mice, while compulsive-like behavior was increased in both male and female mice.  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