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   80297篇
  免费   4100篇
  国内免费   177篇
耳鼻咽喉   967篇
儿科学   1783篇
妇产科学   1662篇
基础医学   10773篇
口腔科学   3024篇
临床医学   6243篇
内科学   19667篇
皮肤病学   1798篇
神经病学   7061篇
特种医学   1885篇
外科学   10526篇
综合类   370篇
一般理论   33篇
预防医学   7043篇
眼科学   1490篇
药学   5500篇
中国医学   297篇
肿瘤学   4452篇
  2024年   49篇
  2023年   484篇
  2022年   286篇
  2021年   1217篇
  2020年   735篇
  2019年   1309篇
  2018年   2422篇
  2017年   1560篇
  2016年   1629篇
  2015年   2186篇
  2014年   2271篇
  2013年   3243篇
  2012年   6995篇
  2011年   7200篇
  2010年   3232篇
  2009年   2354篇
  2008年   6067篇
  2007年   6263篇
  2006年   6218篇
  2005年   5990篇
  2004年   5436篇
  2003年   4956篇
  2002年   4693篇
  2001年   1611篇
  2000年   2112篇
  1999年   1050篇
  1998年   264篇
  1997年   197篇
  1996年   198篇
  1995年   181篇
  1994年   142篇
  1993年   139篇
  1992年   147篇
  1991年   134篇
  1990年   82篇
  1989年   95篇
  1988年   63篇
  1987年   59篇
  1986年   75篇
  1985年   86篇
  1984年   114篇
  1983年   74篇
  1982年   100篇
  1981年   83篇
  1980年   89篇
  1979年   48篇
  1978年   46篇
  1977年   41篇
  1976年   40篇
  1974年   44篇
排序方式: 共有10000条查询结果,搜索用时 62 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.
Melatonin, the main hormone produced by the pineal gland, is secreted in a circadian manner (24‐hr period), and its oscillation influences several circadian biological rhythms, such as the regulation of clock genes expression (chronobiotic effect) and the modulation of several endocrine functions in peripheral tissues. Assuming that the circadian synchronization of clock genes can play a role in the regulation of energy metabolism and it is influenced by melatonin, our study was designed to assess possible alterations as a consequence of melatonin absence on the circadian expression of clock genes in the epididymal adipose tissue of male Wistar rats and the possible metabolic repercussions to this tissue. Our data show that pinealectomy indeed has impacts on molecular events: it abolishes the daily pattern of the expression of Clock, Per2, and Cry1 clock genes and Pparγ expression, significantly increases the amplitude of daily expression of Rev‐erbα, and affects the pattern of and impairs adipokine production, leading to a decrease in leptin levels. However, regarding some metabolic aspects of adipocyte functions, such as its ability to synthesize triacylglycerols from glucose along 24 hr, was not compromised by pinealectomy, although the daily profile of the lipogenic enzymes expression (ATP‐citrate lyase, malic enzyme, fatty acid synthase, and glucose‐6‐phosphate dehydrogenase) was abolished in pinealectomized animals.  相似文献   
7.

Objective

To discover the experiences of end-of-life patients attended by the emergency services, through the discourse of the family caregivers who accompanied the family member in this care transit.

Method

A qualitative approach study, based on the paradigm of hermeneutical phenomenology. In total, 81 family caregivers participated. The techniques used were the in-depth interview and the discussion group, with a total of 5 discussion groups and 41 interviews. The period of data collection was carried out between January 2013 and June 2014.

Results

In the network of discourses obtained with respect to “Urgent Care”, all the codes were grouped in relation to a single argumentative line: deficiencies in urgent care. Among them, we found different dimensions that are established depending on the different times of care, or the different determinant aspects of these deficiencies: disorganization of the care received, lack of experience of the professionals in emergencies, application of general protocols in the emergency services, inadequate care in the treatment received, delays in emergency care.

Conclusions

In general, we highlight the dissatisfaction of the family members with respect to the care received from the emergency services. The needs of these types of situation are not covered from these services and are of low quality. Therefore, it is necessary to reorient the care protocols for these patients.  相似文献   
8.
9.
10.
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