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   12310篇
  免费   668篇
  国内免费   54篇
耳鼻咽喉   85篇
儿科学   483篇
妇产科学   290篇
基础医学   1863篇
口腔科学   213篇
临床医学   1348篇
内科学   2578篇
皮肤病学   241篇
神经病学   1239篇
特种医学   307篇
外科学   1148篇
综合类   78篇
一般理论   9篇
预防医学   1027篇
眼科学   216篇
药学   880篇
中国医学   50篇
肿瘤学   977篇
  2023年   91篇
  2022年   205篇
  2021年   348篇
  2020年   215篇
  2019年   309篇
  2018年   364篇
  2017年   245篇
  2016年   280篇
  2015年   370篇
  2014年   481篇
  2013年   677篇
  2012年   980篇
  2011年   1036篇
  2010年   543篇
  2009年   486篇
  2008年   798篇
  2007年   853篇
  2006年   791篇
  2005年   762篇
  2004年   679篇
  2003年   664篇
  2002年   598篇
  2001年   69篇
  2000年   56篇
  1999年   89篇
  1998年   119篇
  1997年   105篇
  1996年   70篇
  1995年   73篇
  1994年   60篇
  1993年   46篇
  1992年   45篇
  1991年   35篇
  1990年   25篇
  1989年   25篇
  1988年   31篇
  1987年   20篇
  1986年   28篇
  1985年   25篇
  1984年   32篇
  1983年   38篇
  1982年   39篇
  1981年   41篇
  1980年   33篇
  1979年   23篇
  1978年   22篇
  1977年   12篇
  1976年   11篇
  1975年   14篇
  1972年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
The Gingko biloba extract is contraindicated during pregnancy and lactation due to the lack of information about its effects on these reproductive phases. Previous studies have shown that G. biloba extract contains components with estrogenic and antiestrogenic activities, thus nursing dams treated with the extract of this plant could show reduction in milk production, resulting in malnutrition and poor development of pups. This work analyzes the postnatal development of pups, whose mothers were treated with G. biloba extract during the lactation period. Nursing Wistar rats received 3.5 mg/kg/day of G. biloba aqueous extract, corresponding to the highest human dose. Clinical signs of maternal toxicity were evaluated. The growth rate, viability, survival during treatment and lactation indices of the pups were calculated. The physical, motor and sensorial development of the pups was also evaluated. No maternal signs of toxicity were observed. As there were no biological differences between control and G. biloba treated pups, it is possible to assume that, in this experimental design, the administration of G. biloba aqueous extract to nursing rats during the lactation period seems to be devoid of toxic effect to mothers and to the physical, motor and sensory development of the pups.  相似文献   
73.
74.

Objectives

To evaluate the utility and effectiveness of hysteroscopic retrieval of intrauterine devices (IUDs) in early pregnancy.

Subjects and methods

We followed-up four pregnant women with IUDs with retracted tails removed by hysteroscopy before 10 weeks of pregnancy from 2003 to 2005.

Results

After hysteroscopy, pregnancy course was successful in three women, without complications that could be attributed to the procedure. There was one abortion due to rupture of fetal membranes at 15 weeks’ gestation.

Conclusions

The application of hysteroscopy in pregnancy has always been limited. In all patients, a possible optic nerve lesion in the fetus should be evaluated. This technique should not be performed after the 10th week of pregnancy. In most patients, pregnancy continues without complications after IDU removal.  相似文献   
75.
76.
Lipopolysaccharide (LPS) may play an important role in chronic diseases through the activation of inflammatory responses. The type of diet consumed is of major concern for the prevention and treatment of these diseases. Evidence from animal and human studies has shown that LPS can diffuse from the gut to the circulatory system in response to the intake of high amounts of fat. The method by which LPS move into the circulatory system is either through direct diffusion due to intestinal paracellular permeability or through absorption by enterocytes during chylomicron secretion. Considering the impact of metabolic diseases on public health and the association between these diseases and the levels of LPS in the circulatory system, this review will mainly discuss the current knowledge about high-fat diets and subclinical inflammation. It will also describe the new evidence that correlates gut microbiota, intestinal permeability and alkaline phosphatase activity with increased blood LPS levels and the biological effects of this increase, such as insulin resistance. Although the majority of the studies published so far have assessed the effects of dietary fat, additional studies are necessary to deepen the understanding of how the amount, the quality and the structure of the fat may affect endotoxaemia. The potential of food combinations to reduce the negative effects of fat intake should also be considered in future studies. In these studies, the effects of flavonoids, prebiotics and probiotics on endotoxaemia should be investigated. Thus, it is essential to identify dietetic strategies capable of minimising endotoxaemia and its postprandial inflammatory effects.  相似文献   
77.
78.
This study sought to clarify personality characteristics of supporters of the Women's Liberation Movement (WLM) with specific emphasis on the Equal Rights Amendment (ERA). Three matched groups of 50 female college students, which were comprised of supporters, opponents, or those who voiced no opinion on the ERA, were administered the Rokeach Dogmatism Scale and the Rotter I-E Scale. The three groups did not differ significantly on either measure. Participants of all groups were shown to be somewhat externally controlled and to demonstrate personality traits that were not characteristically dogmatic. The disparity of these results with those reported by other researchers was attributed to the matched demographic factors that determined S selection and assignment.  相似文献   
79.
The proportion of women who patronized traditional birth attendants (TBAs) or modern health care practitioners (MHCPs) was compared, including reasons for their choices. A comparative design was adopted to study 300 respondents selected through a multistage systematic random sampling technique. The instrument for data collection was a validated 21-item structured questionnaire. We observed that 75 (25%) patronized and 80 (27%) preferred TBAs, and 206 (69%) patronized and 220 (75%) preferred MHCPs, while 19 (6%) patronized both. The view that TBAs prayed before conducting deliveries was supported by a majority 75 (94%) of the respondents who preferred them. Factors associated with preference for TBAs should be addressed.  相似文献   
80.
Labor flow and travelers are important factors contributing to the spread of Dengue virus infection and chikungunya fever. Bali Province of Indonesia, a popular resort and tourist destination, has these factors and suffers from mosquito-borne infectious diseases. Using area study approach, a series of fieldwork was conducted in Bali to obtain up-to-date primary disease data, to learn more about public health measures, and to interview health officers, hotel personnel, and other resource persons. The national data including information on two other provinces were obtained for comparison. The health ministry reported 5,810 and 11,697 cases of dengue hemorrhagic fever in Bali in 2009 and 2010, respectively. Moreover, two densely populated tourist areas and one district have shown a particularly high incidence and sharp increases in 2010. Cases of chikungunya fever reported in Bali more than doubled in 2010 from the previous year. Our findings suggest that Bali can benefit from a significant reduction in vector populations and dissemination of disease preventive knowledge among both local residents and foreign visitors. This will require a concerted and trans-border approach, which may prove difficult in the province.  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