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   3568篇
  免费   201篇
  国内免费   8篇
耳鼻咽喉   28篇
儿科学   103篇
妇产科学   93篇
基础医学   408篇
口腔科学   49篇
临床医学   479篇
内科学   501篇
皮肤病学   72篇
神经病学   394篇
特种医学   90篇
外科学   411篇
综合类   24篇
一般理论   1篇
预防医学   580篇
眼科学   29篇
药学   204篇
中国医学   6篇
肿瘤学   305篇
  2024年   11篇
  2023年   37篇
  2022年   64篇
  2021年   111篇
  2020年   68篇
  2019年   91篇
  2018年   108篇
  2017年   85篇
  2016年   109篇
  2015年   89篇
  2014年   116篇
  2013年   200篇
  2012年   260篇
  2011年   312篇
  2010年   137篇
  2009年   130篇
  2008年   226篇
  2007年   266篇
  2006年   225篇
  2005年   244篇
  2004年   233篇
  2003年   226篇
  2002年   211篇
  2001年   34篇
  2000年   23篇
  1999年   14篇
  1998年   27篇
  1997年   22篇
  1996年   10篇
  1995年   7篇
  1994年   7篇
  1993年   13篇
  1992年   10篇
  1991年   8篇
  1990年   7篇
  1989年   6篇
  1988年   1篇
  1987年   3篇
  1986年   4篇
  1985年   6篇
  1983年   2篇
  1982年   3篇
  1981年   2篇
  1980年   3篇
  1979年   2篇
  1976年   1篇
  1973年   1篇
  1969年   1篇
  1966年   1篇
排序方式: 共有3777条查询结果,搜索用时 0 毫秒
141.
Cross-sectional studies have demonstrated that left ventricular hypertrophy (LVH) is common in children on maintenance dialysis. We report the echocardiogram results of 17 children from seven centers in the Midwest Pediatric Nephrology Consortium who have spent at least 2 years on maintenance dialysis and had three consecutive echocardiograms: at initiation of dialysis therapy and 1 and 2 years later. The results indicate that LVH is prevalent at the initiation of dialysis (82%) and remains both frequent (82%) and severe (59%) after 2 years of maintenance dialysis. Normalization of LV geometry was unlikely: the prevalence of concentric LVH increased and the prevalence of eccentric LVH did not change over time, indicating poor blood pressure and volume status control in these patients. We conclude that children on maintenance dialysis are at high risk for future cardiovascular disease.  相似文献   
142.
BACKGROUND/OBJECTIVE: Wheelchair-related injuries are common, and with proper reporting of injuries, advanced technologic support may offer new ways to prevent those injuries. METHOD: Case REPORT AND FINDINGS: A man with tetraplegia who retains only minimal use of his right hand experienced a right-sided armrest malfunction of his wheelchair resulting in his wheelchair controls being out of reach. This left him stranded in the sun for almost 2 hours in 86 degrees F weather. During that time, he developed full thickness sunburns of his left forearm and deep partial thickness burns of the left fingertips where they were in contact with the left armrest. CONCLUSION: This patient's full thickness burns could have been prevented if his motorized wheelchair had back-up communication in the event of a malfunction. Technology developers must realize the need for such systems. Health care professionals must advocate for a higher standard of safety and report injuries related to wheelchair malfunction.  相似文献   
143.
144.
Distrust and dissatisfaction with contraceptive methods among low-income Brazilian women contributes to incorrect contraceptive use, harmful health risks, and an extensive reliance on surgical sterilization. Data from ethnographic fieldwork in a low-income neighborhood in urban Brazil illustrate that women's concerns regarding contraception make sense in the context of their general health and illness beliefs and their understanding of reproductive physiology. Women interpret and experience biomedical concepts and contraceptive methods (such as "hormones" and oral contraceptives, respectively) according to an ethnophysiology of fecundity, menstruation, and conception. These popular representations of reproduction embody social relations and local experience and therefore persist despite the influence of biomedical models. Recognition of this ethnophysiology and greater emphasis on culturally appropriate counseling and education among health care professionals will improve women's experience and effective use of reversible contraception.  相似文献   
145.
PURPOSE: To prospectively determine the accuracy of using an ultrasonographic (US) strain imaging technique known as lesion size comparison to differentiate benign from malignant breast lesions. MATERIALS AND METHODS: Institutional Review Board approval and patient informed consent were obtained for this HIPPA-compliant study. US strain imaging was performed prospectively for 89 breast lesions in 88 patients. Lesions were imaged by using freehand compression and a real-time strain imaging algorithm. Five observers obtained manual measurements of lesion height, width, and area from B-mode and strain images. By using these size measurements, individual observer and group performances were assessed by using the area under the receiver operating characteristic curve (A(z)). The performance of a single size parameter versus that of a combination of size parameters was evaluated by using univariate and multivariate logistic regression. RESULTS: Group A(z) values showed that width ratio and area ratio yielded the best results for differentiating benign and malignant breast lesions, and they were not statistically different from one another (P = .499). For the group, the performance of area and width, which was superior to that of height and aspect ratio, was statistically significant for all cases (P < .011) except for those that compared area with aspect ratio (P = .118). By using a group threshold of 1.04 for width ratio and 1.13 for area ratio, the sensitivity and specificity of the technique were 96% and 21%, respectively, for width and 96% and 24%, respectively, for area. The best observer achieved a sensitivity of 96% and a specificity of 61% by using the area ratio. For all but one observer, combined size parameters did not improve observer performance (P > .258). Significant interobserver performance variability was observed (P < .001). CONCLUSION: Results suggest that US strain imaging has the potential to aid diagnosis of breast lesions. However, manually tracing lesion boundaries for size ratio differentiation in a busy clinical setting did not match the diagnostic performance levels previously reported. Focusing on measurements of lesion width, along with additional observer training or automated processes, may yield a suitable method for routine clinical application.  相似文献   
146.
147.
148.
149.
150.
Achieving secure bony fixation of medial canthus is a challenge. We used a resorbable poly-L-lactic acid-polyglycolic acid screw (LactoSorb office fixation kit) in 5 cases: 2 with traumatic medial canthal dystopia, 1 with scleroderma and orbital fat atrophy causing malapposition of the medial canthus to globe, and 2 with invasive medial canthal tumors necessitating subtotal medial orbital exenteration. The resorbable screw with preplaced suture was drilled into the medial orbital wall, using a handheld self-drilling tap. The preplaced suture was used to anchor the medial canthus. We achieved satisfactory canthal position in all 5 cases. There were no complications in 4 cases during a mean +/- SD follow-up of 11.3 +/- 6 months; however, the scleroderma case developed wound dehiscence 6 weeks after surgery. The LactoSorb kit is a safe and effective technique to achieve bony medial canthal fixation in carefully selected cases.  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