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   19489篇
  免费   1956篇
  国内免费   42篇
耳鼻咽喉   266篇
儿科学   721篇
妇产科学   537篇
基础医学   2784篇
口腔科学   598篇
临床医学   2374篇
内科学   3617篇
皮肤病学   336篇
神经病学   1683篇
特种医学   885篇
外科学   2306篇
综合类   507篇
一般理论   9篇
预防医学   2009篇
眼科学   281篇
药学   1528篇
  2篇
中国医学   23篇
肿瘤学   1021篇
  2021年   287篇
  2020年   174篇
  2019年   287篇
  2018年   346篇
  2017年   266篇
  2016年   286篇
  2015年   312篇
  2014年   436篇
  2013年   629篇
  2012年   793篇
  2011年   819篇
  2010年   534篇
  2009年   453篇
  2008年   836篇
  2007年   836篇
  2006年   859篇
  2005年   728篇
  2004年   713篇
  2003年   653篇
  2002年   670篇
  2001年   624篇
  2000年   661篇
  1999年   540篇
  1998年   282篇
  1997年   221篇
  1996年   244篇
  1995年   228篇
  1994年   203篇
  1993年   238篇
  1992年   456篇
  1991年   432篇
  1990年   430篇
  1989年   471篇
  1988年   446篇
  1987年   360篇
  1986年   373篇
  1985年   419篇
  1984年   280篇
  1983年   227篇
  1982年   167篇
  1981年   172篇
  1979年   215篇
  1978年   191篇
  1977年   214篇
  1976年   179篇
  1975年   165篇
  1974年   172篇
  1973年   181篇
  1972年   169篇
  1971年   163篇
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
121.
Bulimia nervosa in the male: a report of nine cases   总被引:1,自引:0,他引:1  
Nine male patients with bulimia nervosa, accounting for one in 24 bulimic patients attending a clinic for eating disorders, are described. Symptomatology and demographic characteristics were similar in males and females. A history of either anorexia nervosa or obesity was always present, and a chronic course was seen in 6 patients. Five of the men showed atypical sexuality.  相似文献   
122.
Advances in genetic engineering have created opportunities for improved understanding of the molecular basis of carcinogenesis. Through selective introduction, activation, and inactivation of specific genes, investigators can produce mice of unique genotypes and phenotypes that afford insights into the events and mechanisms responsible for tumor formation. It has been suggested that such animals might be used for routine testing of chemicals to determine their carcinogenic potential because the animals may be mechanistically relevant for understanding and predicting the human response to exposure to the chemical being tested. Before transgenic and knockout mice can be used as an adjunct or alternative to the conventional 2-year rodent bioassay, information related to the animal line to be used, study design, and data analysis and interpretation must be carefully considered. Here, we identify and review such information relative to Tg.AC and rasH2 transgenic mice and p53+/- and XPA-/- knockout mice, all of which have been proposed for use in chemical carcinogenicity testing. In addition, the implications of findings of tumors in transgenic and knockout animals when exposed to chemicals is discussed in the context of human health risk assessment.  相似文献   
123.
The in vitro invasive behaviour of six meningioma cell lines of various histological sub-type and grade was assessed using Boyden chemotaxis chambers ('Transwell' units) precoated with various extracellular matrix proteins. The cell lines included a benign meningothelial (IPGS), two benign transitional (IPCBR and IPGC), one atypical (IPIH) and two malignant (IPSE and IPIR) meningiomas. IPGC was a recurrent tumour. The results showed that IPCBR was most invasive through laminin and vitronectin. IPIH was moderately invasive through collagen type IV, laminin, vitronectin and fibronectin. However, both IPSE and IPIR were less invasive than IPIH whereas, IPGS was least invasive of all. Moreover, laminin was the most permissive extracellular matrix protein for most cell lines and collagen type IV, the least permissive. These results show that there is a differential in vitro invasive behaviour of cell lines derived from different histological types of meningiomas according to extracellular matrix substrate and suggests that invasion and migration of meningiomas in situ might be modulated by various extracellular components.  相似文献   
124.
We describe an amperometric technique for quantification of an enzyme immunoassay in which we use a magnetic working electrode, both to separate bound and free analyte and to monitor the electrochemical response. We used a "two-site" immunometric assay with monoclonal antibodies for human choriogonadotropin (hCG) as a model system in which magnetic particles were used as the solid phase. Separation of bound and free label is readily achieved by localizing the particles at the electrode. Activity of the bound enzyme in the environment of the electrode is determined electrochemically, permitting rapid quantification of the analyte without the need for a separate incubation step to measure enzyme activity. The sensitivity of the system is 150 int. units of hCG per litre (1st Int. Ref. Preparation). Correlation between the amperometric measurement of urinary hCG and data for an immunoradiometric assay was r = 0.9. The assay is rapid, requiring a total assay time for each sample of 20 min, which includes 15 min for antibody/antigen binding.  相似文献   
125.
B E Robinson 《Geriatrics》1986,41(2):75-7, 81, 84 passim
A common mistake is prematurely reassuring the patient and family that "nothing is wrong" if history and physical--with or without a brief mental status exam--is reasonably normal. Caregivers should be informed that although a cure for dementia is seldom found, there often are targets for medical intervention that could lead to improved mental and physical function for the patient.  相似文献   
126.
Philosophical origins of the economic valuation of life   总被引:5,自引:0,他引:5  
Cost-benefit analysis--applying economic reasoning to increasingly complex health policy decisions--continues to be a source of vehement disagreement among its practitioners. re than merely technical issues in measurement and accounting are involved; basic social values embedded in different intellectual traditions are coming into conflict. The "human capital" and "willingness-to-pay" approaches can each aid policy formulation, but neither can substitute for open political process.  相似文献   
127.
128.
The Journal of Behavioral Health Services & Research - Characterizing community mental health (CMH) treatment duration and discharge is an important step toward understanding how to better meet...  相似文献   
129.
ObjectivesTo examine the effectiveness of game-based interventions compared with usual care on health-related outcomes for acutely hospitalized older patients.DesignSystematic review of randomized controlled trials (RCT) and nonrandomized trials.Setting and ParticipantsAdults aged 65 years or older admitted to an Acute Care for Elderly unit were selected.MeasuresHealth-related outcomes (eg, functional capacity, quality of life, adherence to treatment).ResultsFour RCTs were included in the review. The interventions were based on the implementation of serious-game programs using Nintendo Wii in acute medical patients. Across the included studies, no significant differences were observed between groups on functional capacity and health-related quality of life. Significant differences were found between groups on the adherence to treatment (in favor of the control group), but no differences were obtained in other outcomes such as enjoyment and motivation.Conclusions and ImplicationsIn general, there is very limited evidence for the efficacy to reach conclusions about the effects of game-based interventions on health-related outcomes in acutely hospitalized older patients. Future studies are needed to improve our knowledge in the field; however, we consider that these strategies should be considered in the future complementary to usual care.  相似文献   
130.
Both the fields of public health and that of human rights seek to improve human well-being, including through reducing and preventing all forms of violence, to help individuals attain the highest quality of life. In both fields, mathematical methods can help “visibilize” the hidden architecture of violence, bringing new methods to bear to understand the scope and nuance of how violence affects populations. An increasing number of studies have examined how residing in a conflict-affected place may impact one of the most pervasive forms of violence—intimate partner violence (IPV)—during and after conflict. This paper contributes to this effort by examining whether severe forms of IPV are associated with previous experience of political violence in one conflict-affected country: Liberia. Our findings indicate that living in a district with conflict fatalities increased the risk of IPV among women by roughly 60%. Additionally, living in a district with conflict fatalities increased the risk of a past-year injury from IPV by 50%. This analysis brings to light links between two of the most pervasive forms of violence—political violence and violence against women. The findings suggest that women residing in a district that is more highly affected by conflict, not only people experiencing direct trauma during conflict, may be at risk of increased violence long after peace is declared. These findings point to the need for targeted programs that address IPV postconflict.  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