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   27061篇
  免费   4023篇
  国内免费   162篇
耳鼻咽喉   535篇
儿科学   833篇
妇产科学   695篇
基础医学   2950篇
口腔科学   587篇
临床医学   4575篇
内科学   5629篇
皮肤病学   828篇
神经病学   2269篇
特种医学   876篇
外国民族医学   1篇
外科学   3537篇
综合类   569篇
现状与发展   2篇
一般理论   20篇
预防医学   3309篇
眼科学   552篇
药学   1209篇
  1篇
中国医学   102篇
肿瘤学   2167篇
  2023年   462篇
  2022年   207篇
  2021年   464篇
  2020年   604篇
  2019年   367篇
  2018年   804篇
  2017年   766篇
  2016年   828篇
  2015年   934篇
  2014年   1023篇
  2013年   1509篇
  2012年   1092篇
  2011年   1065篇
  2010年   898篇
  2009年   1019篇
  2008年   1021篇
  2007年   961篇
  2006年   986篇
  2005年   936篇
  2004年   802篇
  2003年   767篇
  2002年   754篇
  2001年   811篇
  2000年   827篇
  1999年   717篇
  1998年   495篇
  1997年   474篇
  1996年   474篇
  1995年   426篇
  1994年   335篇
  1993年   280篇
  1992年   579篇
  1991年   575篇
  1990年   509篇
  1989年   532篇
  1988年   480篇
  1987年   483篇
  1986年   451篇
  1985年   437篇
  1984年   401篇
  1983年   283篇
  1982年   192篇
  1981年   205篇
  1980年   212篇
  1979年   276篇
  1978年   228篇
  1977年   184篇
  1976年   191篇
  1974年   220篇
  1973年   205篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Although the prevalence of cardiovascular complications is increased in insulin-resistant individuals, the underlying causes of this link have been elusive. Recent work suggests that several intracellular signal transduction pathways are inappropriately activated by hyperinsulinemia, hyperglycemia, increased free fatty acids, dyslipidemia, various inflammatory cytokines and adipokines--factors that are increased in insulin resistance. Once activated, substantial cross talk occurs between these pathways, especially a self-reinforcing cascade of vascular inflammation and cell dysfunction, greatly increasing the risk and severity of atherosclerosis in the insulin-resistant individual. We review several key cell-signalling pathways, describe how they are activated in they insulin-resistant state and the damage they induce, and discusses possible therapeutic approaches to limit vascular damage.  相似文献   
62.
Efforts to control chlamydial and gonococcal infections include notifying eligible sexual partners of possible infection, primarily by asking the diagnosed patient to notify their partners. This approach, known as patient referral, is widely used but poorly understood. The current study examined psychosocial and cognitive factors associated with patient referral among an urban, minority sample of 168 participants recently diagnosed with Chlamydia trachomatis or Neisseria gonorrhoeae. At a follow-up interview 1-month from diagnosis, participants were more likely to have notified all eligible partners if they had greater intention to notify at baseline (OR = 3.72; 95% CI = 1.34, 10.30) and if they had only one partner at baseline (OR = 4.08; 95% CI = 1.61, 10.31). There were also gender differences as well as differences based on type of partner (i.e., regular, casual, one-time). The implications of these findings for the design of programs to promote patient referral for sexually transmitted infections are discussed. Schwartz, Malka, Augenbraun, McCormack, and Wilson are with the State University of New York, Downstate Medical Center, Brooklyn, NY, USA; Rubin is with the New York City Department of Health, Bureau of STD Control, New York, NY, USA; Rubin, Hogben, and Liddon are with the Centers for Disease Control and Prevention, Atlanta, GA, USA; Schwartz is with the Department of Preventive Medicine and Community Health, SUNY Downstate Medical Center, Box 1240, 450 Clarkson Avenue, Brooklyn, NY 11203, USA.  相似文献   
63.
64.
Noninsulin dependent diabetes (type II diabetes) is a chronic disease characterized by hyperglycemia. Clients can generally be controlled by diet and exercise or a combination of diet, exercise, and oral hypoglycemic agents. When this therapy is not effective in controlling the hyperglycemia, the health care provider must choose to initiate insulin therapy. Outpatient initiation of insulin is an alternative to hospitalization in the type II diabetic client. Clinical guidelines for the initiation of insulin on an outpatient basis and management of the diabetic client are presented.  相似文献   
65.
Implant surface morphology regulates osteoblast phenotypic expression. Osteoblast sensitivity to non-biologic surfaces suggests that native bone surface features may also affect osteoblast response. To test this, MG63 osteoblast-like cells were grown for 7 days on bovine cortical bone wafers pretreated with rat bone marrow osteoclasts for 0, 10 or 20 days. Response to osteoclast-treated surfaces was compared to the response of MG63 cells to titanium surfaces with smooth and rough microtopographies. Cell number, differentiation (alkaline phosphatase activity and osteocalcin levels), and local factors (PGE(2) and TGF-beta1) were measured in confluent cultures. Compared to culture on plastic, cell number was reduced on all three types of bone wafers; this effect was dose-dependent with increasing resorption of the surface. Alkaline phosphatase specific activity was increased (P相似文献   
66.
Previous studies have demonstrated that vein storage in normal saline leads to significant mechanical morphological, and biochemical aberrations. However, little information is available regarding the functional damage that occurs. The purpose of this study was to evaluate the effect of saline storage on venous smooth muscle and endothelial function. Segments of ten external jugular veins from male New Zealand White rabbits were placed nondistended in either modified Krebs solution at 37 degrees C (Krebs-stored, KS) or heparinized normal saline at room temperature (saline-stored, SS) for 1 h. Segments 4 mm in length were then simultaneously studied in vitro under isometric tension. There was no difference in maximum tension or sensitivity to either bradykinin or histamine. Acetylcholine-induced relaxation in KS segments was not significantly different from relaxation in a historical cohort of nonstored segments (nonstored 87.4 +/- 1.0% vs. KS 84.5 +/- 2.0%; p = NS). However, there were significant attenuations in SS segment endothelium-dependent relaxation in response to both acetylcholine (KS 84.5 +/- 2.0% vs. SS 76.4 +/- 2.7%, p less than 0.02) and adenosine diphosphate (KS 47.9 +/- 2.9% vs. SS 40.6 +/- 3.7%, p less than 0.002). Relaxant responses to sodium nitroprusside (endothelium-independent) were not significantly different in the two groups (KS 94.6 +/- 1.6% vs. SS 95.7 +/- 2.2%; p = NS). Electron microscopic evaluation of SS segments revealed endothelial cell disruption with cellular edema and loss of intact junctions.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
67.
68.
The current study evaluated psychosocial variables that may contribute to the experience of headache in college adults. One hundred ninety-nine participants, 103 women and 96 men, completed head pain logs for 4 weeks after completing measures assessing psychosocial variables. Multiple regression analyses indicated that level of emotional functioning, perception of stress, and gender were predictive of future headache frequency, intensity, and duration. Family history and health habits did not predict headache activity. These findings are consistent with research investigating psychosocial variables and headache activity.  相似文献   
69.
The information needs of women newly diagnosed with breast cancer   总被引:4,自引:0,他引:4  
Nurses can play a key role in patient education, including providing patients with useful and approrate information Rather than focusing on the process of education or information giving by nurses, this study places emphasis on the content of that information by taking the patients'perspective and asking the patients themselves what particular types of information are perceived as important at a specific point in time The aim of the study was to explore what particular types of information were important to women newly diagnosed with breast cancer, to enable nurses and other health care professionals to utilize their time as effectively as possible and provide a high-quality service to individuals in their care Women with breast cancer (a mean of 2 5 weeks from diagnosis) were interviewed and asked to compare items of information The items of information were presented m pairs and the women stated a preference for one item in that pan- Thirty-six pairs were presented in total The analysis involved the use of a Thurstone scaling model, which allowed rank ordermgs, or profiles of information needs, to be developed, reflecting the perceived importance of each item Information about the likelihood of cure, the spread of the disease and treatment options were perceived as the most important items of information at the tune of diagnosis Other information needs, in order of descending priority, included information about the risk to family, side-effects  相似文献   
70.
When children are ill enough to require admission to paediatric intensive care, parents may become distressed about their child's medical condition and this distress may be compounded by the unfamiliar nature of the highly technological environment Parents of children who are sick enough to warrant intubation are particularly likely to be exposed to a frightening array of technological equipment Seventy-one parents of intubated and non-intubated children completed the Parental Stressor Scale Paediatnc Intensive Care Unit (PSS PICU) Overall the findings suggest that parents were most distressed (a) by the painful procedures to which their children were subjected, (b) by the sights and sounds of the intensive care unit and (c) by their children's reactions to intensive care The behaviour of staff towards parents and the way that staff communicated with them caused the least distress When the levels of stress reported by parents of intubated children were compared with those reported by parents of non-intubated children, different patterns of stress were found Painful procedures were a source of greater stress to parents of intubated children whereas the behaviour of staff and the children's reactions to the intensive care experience caused greater stress to the parents of the non-intubated children In general the findings suggest that the needs of parents of non-intubated children are being overlooked, with staff focusing more of their attention on the parents of intubated children  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