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   25683篇
  免费   1953篇
  国内免费   162篇
耳鼻咽喉   293篇
儿科学   772篇
妇产科学   463篇
基础医学   2850篇
口腔科学   498篇
临床医学   2701篇
内科学   5654篇
皮肤病学   417篇
神经病学   2411篇
特种医学   977篇
外国民族医学   2篇
外科学   3929篇
综合类   589篇
一般理论   26篇
预防医学   2148篇
眼科学   663篇
药学   1661篇
中国医学   36篇
肿瘤学   1708篇
  2022年   204篇
  2021年   451篇
  2020年   268篇
  2019年   424篇
  2018年   475篇
  2017年   351篇
  2016年   338篇
  2015年   468篇
  2014年   633篇
  2013年   986篇
  2012年   1421篇
  2011年   1400篇
  2010年   844篇
  2009年   749篇
  2008年   1291篇
  2007年   1442篇
  2006年   1420篇
  2005年   1416篇
  2004年   1333篇
  2003年   1254篇
  2002年   1209篇
  2001年   392篇
  2000年   344篇
  1999年   385篇
  1998年   351篇
  1997年   287篇
  1996年   320篇
  1995年   256篇
  1994年   224篇
  1993年   223篇
  1992年   276篇
  1991年   238篇
  1990年   286篇
  1989年   231篇
  1988年   262篇
  1987年   252篇
  1986年   232篇
  1985年   234篇
  1984年   238篇
  1983年   230篇
  1982年   238篇
  1981年   233篇
  1980年   238篇
  1979年   219篇
  1978年   179篇
  1977年   152篇
  1976年   153篇
  1975年   137篇
  1974年   156篇
  1973年   133篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
Purpose.?Guillain-Barré syndrome (GBS) is a transient inflammatory disorder affecting peripheral nerves, characterised by weakness and numbness in limbs, upper body and face. Residual problems affect a large minority, and complicate return to work. This qualitative study explored the experiences of people who returned to work following their diagnosis of GBS and recovery, to gain insight into factors that facilitated or inhibited this process.

Method.?Five people participated in in-depth interviews. Individual and common experiences were explored through interpretative phenomenological analysis.

Findings.?Three recurring themes are presented: the perceived value of work; losing and recovering a familiar identity at work; and dilemmas around using support and adaptations at work. Certain individual issues also emerged but are beyond the scope of this article. Participants tended to measure their recovery in terms of returning to work yet continued to experience certain physical and psychosocial difficulties at work related to GBS, which required active coping strategies. Limited public awareness of GBS was perceived as a hindrance when returning to work.

Conclusion.?This study provides a rich account of the experiences that people encounter returning to work following GBS. Rehabilitation specialists may offer more effective preparation for this process, drawing upon the issues identified.  相似文献   
942.
Bone adaptation to its mechanical environment, from embryonic through adult life, is thought to be the product of increased osteoblastic differentiation from mesenchymal stem cells. In parallel with tissue-scale loading, these heterogeneous populations of multipotent stem cells are subject to a variety of biophysical cues within their native microenvironments. Bone marrow-derived mesenchymal stem cells—the most broadly studied source of osteoblastic progenitors—undergo osteoblastic differentiation in vitro in response to biophysical signals, including hydrostatic pressure, fluid flow and accompanying shear stress, substrate strain and stiffness, substrate topography, and electromagnetic fields. Furthermore, stem cells may be subject to indirect regulation by mechano-sensing osteocytes positioned to more readily detect these same loading-induced signals within the bone matrix. Such paracrine and juxtacrine regulation of differentiation by osteocytes occurs in vitro. Further studies are needed to confirm both direct and indirect mechanisms of biophysical regulation within the in vivo stem cell niche.  相似文献   
943.
Moderate weight loss (> 5%), which has been associated with improvements in glycemic parameters in patients with dysglycemia, also reduces the presence of other comorbidities, including dyslipidemia and hypertension, culminating in a reduced risk of cardiovascular disease. Lifestyle changes are the recommended preliminary approach to weight loss, with an initial weight-loss goal of 10% of body weight achieved over 6 months at a rate of 1–2 pounds per week selected as an appropriate target to decrease the severity of obesity-related risk factors. Implementing and maintaining the lifestyle changes associated with weight loss can, however, be challenging for many patients. Therefore, additional interventions sometimes may be necessary. Bariatric surgery can also be a highly effective option for weight loss and comorbidity reduction, but surgery carries considerable risks and is still applicable only to selected patients with type 2 diabetes. Thus, attention is turning to the use of weight-loss medications, including 2 recently approved compounds: twice-daily lorcaserin and a once-daily combination of phentermine and topiramate extended-release, both shown to be safe and effective therapies in the management of obesity in patients with type 2 diabetes.  相似文献   
944.
ABSTRACT: BACKGROUND: This study examines the psychometric properties of 9 items on the Patient Activation component of the Medicare Current Beneficiary Survey (MCBS) that assess how patients approach and communicate with their physicians. The MCBS is a nationally representative, cross-sectional survey of Medicare beneficiaries. METHODS: We analyzed MCBS data collected in 2002 and 2005 from 15,165 adults aged 65 and older. Exploratory factor analysis was conducted using maximum likelihood to estimate a polychoric correlation matrix on the 2002 data, and confirmatory factor analysis was performed using the 2005 data. RESULTS: Exploratory factor analysis of the 2002 data showed a 2-factor solution: approach to interactions (5 items) and views about physician's healthcare communication (6 items). Findings were confirmed using the 2005 data. Items were combined to form the Patient Approach and Views toward Healthcare Communication (PAV-COM) scale (range 1 to 100; Cronbach's alpha of 0.75, and item-rest correlations between 0.33 and 0.54). Higher PAV-COM scores were associated with greater fulfillment of preventive health behaviors such as vaccinations and cancer screenings. CONCLUSIONS: The PAV-COM measure is a valid tool for assessing patient approaches and views toward communication with physicians. This measure can be used to evaluate interventions to improve patient participation during healthcare encounters.  相似文献   
945.
Staphylococcus aureus is the leading cause of bacterial infections in developed countries and produces a wide spectrum of diseases, ranging from minor skin infections to fatal necrotizing pneumonia. Although S. aureus infections were historically treatable with common antibiotics, emergence of drug-resistant organisms is now a major concern. Methicillin-resistant S. aureus (MRSA) was endemic in hospitals by the late 1960s, but it appeared rapidly and unexpectedly in communities in the 1990s and is now prevalent worldwide. This Review focuses on progress made toward understanding the success of community-associated MRSA as a human pathogen, with an emphasis on genome-wide approaches and virulence determinants.  相似文献   
946.
947.
948.
目的 评价各种数据缺失机制对逐步回归变量筛选结果的影响.方法 通过模拟产生不同缺失机制和缺失类型的数据,用筛选到的真实变量的个数和损失函数大小作为指标,评价其对逐步同归的影响.结果 完整数据情况下的筛选表现优于各缺失机制卜表现;缺失类型比缺失机制对筛选结果的影响更为明显.结论用逐步回归对含缺失值的数据进行变量筛选时,需要关注缺失机制和缺失类型.  相似文献   
949.
950.
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