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   31101篇
  免费   2562篇
  国内免费   65篇
耳鼻咽喉   287篇
儿科学   1042篇
妇产科学   880篇
基础医学   4101篇
口腔科学   380篇
临床医学   5032篇
内科学   5425篇
皮肤病学   418篇
神经病学   3159篇
特种医学   635篇
外科学   2852篇
综合类   518篇
一般理论   54篇
预防医学   4299篇
眼科学   315篇
药学   2157篇
中国医学   27篇
肿瘤学   2147篇
  2023年   159篇
  2022年   253篇
  2021年   590篇
  2020年   374篇
  2019年   565篇
  2018年   658篇
  2017年   486篇
  2016年   516篇
  2015年   598篇
  2014年   808篇
  2013年   1387篇
  2012年   2014篇
  2011年   2035篇
  2010年   1112篇
  2009年   1028篇
  2008年   1914篇
  2007年   2094篇
  2006年   1955篇
  2005年   1940篇
  2004年   1914篇
  2003年   1728篇
  2002年   1714篇
  2001年   400篇
  2000年   355篇
  1999年   395篇
  1998年   443篇
  1997年   348篇
  1996年   318篇
  1995年   286篇
  1994年   264篇
  1993年   249篇
  1992年   257篇
  1991年   213篇
  1990年   269篇
  1989年   201篇
  1988年   211篇
  1987年   175篇
  1986年   189篇
  1985年   188篇
  1984年   185篇
  1983年   177篇
  1982年   234篇
  1981年   191篇
  1980年   189篇
  1979年   155篇
  1978年   157篇
  1977年   137篇
  1975年   129篇
  1974年   142篇
  1973年   139篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
The regulation of heat shock protein 70 (HSP 70) expression was examined in the isolated, red blood cell-perfused rabbit heart by Northern and Western blot analysis. In the isovolumic (balloon in left ventricle), isolated perfused heart, HSP 70 mRNA was increased threefold after 30 min and sevenfold at 2 and 4 h compared to normal, nonperfused hearts. To further elucidate the etiology of the increase in HSP 70 mRNA, the effects of decreased systolic shortening (isovolumic heart) and of a single ventricular stretch were examined. Perfusion without the application of a stretch or the presence of a balloon resulted in no increase in HSP 70 mRNA; while a single stretch resulted in a threefold increase in HSP 70 mRNA. These changes were accompanied by an increase in HSP 70 protein by Western blot analysis. To elucidate the signalling mechanism mediating the increase in HSP 70, hearts were perfused with H7, a protein kinase C inhibitor. H7 did not prevent the induction of HSP 70. These results indicate that initiation of expression of myocardial HSP 70 can be stimulated by a single myocardial stretch or by prevention of systolic shortening. These mechanisms may contribute to the rapid expression of HSP 70 after coronary occlusion when dyskinesis, reduced systolic shortening, and increased diastolic segment length all occur.  相似文献   
34.
OBJECTIVE: To assess the impact and cost-effectiveness of two information-based provider reminder interventions designed to improve self-care management and outcomes of heart failure (HF) patients. DATA SOURCES/STUDY SETTING: Interview and agency administrative data on 628 home care patients with a primary diagnosis of HF. STUDY DESIGN: Patients were treated by nurses randomly assigned to usual care or one of two intervention groups. The basic intervention was an e-mail to the patient's nurse highlighting six HF-specific clinical recommendations. The augmented intervention supplemented the initial nurse reminder with additional clinician and patient resources. DATA COLLECTION: Patient interviews were conducted 45 days post admission to measure self-management behaviors, HF-specific outcomes (Kansas City Cardiomyopathy Questionnaire-KCCQ), health-related quality of life (EuroQoL), and service use. PRINCIPAL FINDINGS: Both interventions improved the mean KCCQ summary score (15.3 and 12.9 percent, respectively) relative to usual care (p< or =.05). The basic intervention also yielded a higher EuroQoL score relative to usual care (p< or =.05). In addition, the interventions had a positive impact on medication knowledge, diet, and weight monitoring. The basic intervention was more cost-effective than the augmented intervention in improving clinical outcomes. CONCLUSIONS: This study demonstrates the positive impact of targeting evidence-based computer reminders to home health nurses to improve patient self-care behaviors, knowledge, and clinical outcomes. It also advances the field's limited understanding of the cost-effectiveness of selected strategies for translating research into practice.  相似文献   
35.
The importance of incorporating patient and provider decision-making processes is in the forefront of the National Institute of Mental Health (NIMH) agenda for improving mental health interventions and services. Key concepts in patient decision making are highlighted within a simplified model of patient decision making that links patient-level/"micro" variables to services-level/"macro" variables via the decision-making process that is a target for interventions. The prospective agenda for incorporating decision-making concepts in mental health research includes (a) improved measures for characterizing decision-making processes that are matched to study populations, complexity, and types of decision making; (b) testing decision aids in effectiveness research for diverse populations and clinical settings; and (c) improving the understanding and incorporation of preference concepts in enhanced intervention designs.  相似文献   
36.
37.
38.
OBJECTIVE: To assess the feasibility and accuracy of a drill template for the placement of a cervical pedicle screw in a single vertebral level. MATERIALS AND METHODS: A volumetric CT scan was performed on a cadaver cervical spine. Using computer software, a drill template with a predefined trajectory was constructed that was designed to match the posterior surface of the right side of the fifth cervical vertebra. A physical template was created from the computer model using a rapid prototyping machine. The drill template was used to guide drilling of a pilot hole, and a CT scan was performed to assess the accuracy of this hole. A 3.5-mm diameter pedicle screw was placed in the pilot hole. The spine was then dissected to separate the vertebrae and the trajectory of the screw was visually inspected. RESULTS: The feasibility of this patient-specific rapid prototyping technique was demonstrated. Imaging and visual inspection confirmed accurate placement of the pilot hole and cervical pedicle screw without cortical violation. CONCLUSIONS: The potential use of drill templates to place cervical pedicle screws is promising. Our initial methodology appears to provide an accurate technique and trajectory for pedicle screw placement in the cervical spine.  相似文献   
39.
Reduced bone mineral density (BMD) was sporadically reported in patients with Marfan syndrome. This may or may not place the Marfan patient at increased risk for bone fracture. In comparing the BMDs of our patients with those reported in the literature, it seemed that agreement between values, and hence the degree of osteoporosis or osteopenia reported, was dependent on the instrumentation used. The objective of this study was to statistically assess this impression. Bone mineral density measurements from our previously published study of 30 adults with Marfan syndrome performed on a Lunar DPXL machine were compared with studies published between 1993–2000 measured using either Lunar or Hologic bone densitometry instruments. The differences of our measurements compared with those made on other Lunar machines were not statistically significant, but did differ significantly with published results from Hologic machines (P < 0.001). Before progress can be made in the assessment of BMD and fracture risk in Marfan patients and in the evidence-based orthopedic management of these patients, standardization of instrumental bone density determinations will be required along with considerations of height, obesity, age, and sex.  相似文献   
40.
In an outpatient rehabilitation setting, both patients’ use and therapists’ knowledge of complementary and alternative medicine (CAM) varies widely. Based on this observation and a recognition of CAM as an emerging practice area for rehabilitation professionals, it was felt that a thorough and consistent approach to the education and orientation of physical therapists to the world of CAM and integrative care was needed. This special interest paper will describe one center’s approach, development, and use of a unique and comprehensive training manual designed to provide both a structured and standardized approach for educating physical therapists about CAM and related therapeutic modalities. This innovative teaching tool allows for multiple methods of content delivery within a multidisciplinary format and can be used for those who practice currently or desire to practice in an integrative care environment.  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