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   24853篇
  免费   1950篇
  国内免费   102篇
耳鼻咽喉   292篇
儿科学   729篇
妇产科学   456篇
基础医学   2809篇
口腔科学   485篇
临床医学   2571篇
内科学   5416篇
皮肤病学   400篇
神经病学   2396篇
特种医学   749篇
外国民族医学   2篇
外科学   3893篇
综合类   562篇
一般理论   26篇
预防医学   2118篇
眼科学   655篇
药学   1631篇
中国医学   34篇
肿瘤学   1681篇
  2022年   168篇
  2021年   441篇
  2020年   265篇
  2019年   421篇
  2018年   463篇
  2017年   348篇
  2016年   337篇
  2015年   455篇
  2014年   620篇
  2013年   963篇
  2012年   1412篇
  2011年   1392篇
  2010年   824篇
  2009年   729篇
  2008年   1280篇
  2007年   1398篇
  2006年   1415篇
  2005年   1404篇
  2004年   1323篇
  2003年   1247篇
  2002年   1204篇
  2001年   384篇
  2000年   339篇
  1999年   374篇
  1998年   300篇
  1997年   252篇
  1996年   261篇
  1995年   212篇
  1994年   184篇
  1993年   174篇
  1992年   268篇
  1991年   228篇
  1990年   268篇
  1989年   204篇
  1988年   229篇
  1987年   218篇
  1986年   207篇
  1985年   205篇
  1984年   222篇
  1983年   220篇
  1982年   226篇
  1981年   211篇
  1980年   219篇
  1979年   213篇
  1978年   170篇
  1977年   138篇
  1976年   146篇
  1975年   128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 209 毫秒
991.
Investigated the relationships between computer-simulated, in-vitro interactional personality behavior and various indices of interpersonal relationships using data collected from 31 families. Interpersonal strife scores for each of 31 family triads developed via mathematical simulation using a systems approach correlated significantly with 6 of the 10 personal relationship variables. Stepwise regression analysis showed that strife for this sample was allied most closely with rigid, unstable interpersonal interactions. It was concluded that (1) mathematical simulation of interpersonal behavior shows validity for group behavior as well as dyadic behavior; and (2) the systems approach offers a unique, in-vitro way of studying and diagnosing interpersonal difficulties.  相似文献   
992.
Incorporation of radioactive precursors into macromolecules was studied with human normal and osteoarthritic articular cartilage organ culture. Analysis of the salt extracted matrix components separated by cesium chloride buoyant density gradient centrifugation showed an increase in the specific activities of all gradient fractions prepared from the osteoarthritic cartilage. Further analysis of these fractions showed the osteoarthritic cartilage contained 5 times as much sulfate incorporated into proteoglycans, and an even greater amount of 3H-glucosamine incorporated into material sedimenting to the middle of the gradient. Greater than half of this radioactive middle fraction appears to be hyaluronate, as judged by the position it elutes from a DEAE column and its susceptibility to hyaluronidase digestion. This study supports earlier findings showing increased rates of macromolecular synthesis in osteoarthritis, and in addition, an even greater synthetic rate for hyaluronic acid is demonstrated.  相似文献   
993.
This is one of a series of biographic sketches of outstanding physicians of the past from each of the 50 states. The subjects have been selected by the medical society of each state or its designated committee.  相似文献   
994.
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   
995.
The Movement Disorder Society-UPDRS (MDS-UPDRS) was published in 2008, showing satisfactory clinimetric results and has been proposed as the official benchmark scale for Parkinson’s disease. The present study, based on the official MDS-UPDRS Spanish version, performed the first independent testing of the scale and adds information on its clinimetric properties. The cross-culturally adapted MDS-UPDRS Spanish version showed a comparative fit index ≥0.90 for each part (I–IV) relative to the English-language version and was accepted as the Official MDS-UPDRS Spanish version. Data from this scale, applied with other assessments to Spanish-speaking Parkinson’s disease patients in five countries, were analyzed for an independent and complementary clinimetric evaluation. In total, 435 patients were included. Missing data were negligible and moderate floor effect (30 %) was found for Part IV. Cronbach’s α index ranged between 0.79 and 0.93 and only five items did not reach the 0.30 threshold value of item-total correlation. Test–retest reliability was adequate with only two sub-scores of the item 3.17, Rest tremor amplitude, reaching κ values lower than 0.60. The intraclass correlation coefficient was higher than 0.85 for the total score of each part. Correlation of the MDS-UPDRS parts with other measures for related constructs was high (≥0.60) and the standard error of measurement lower than one-third baseline standard deviation for all subscales. Results confirm those of the original study and add information on scale reliability, construct validity, and precision. The MDS-UPDRS Spanish version shows satisfactory clinimetric characteristics.  相似文献   
996.
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   
997.
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   
998.
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   
999.
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   
1000.
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