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   1605篇
  免费   85篇
  国内免费   4篇
耳鼻咽喉   18篇
儿科学   50篇
妇产科学   43篇
基础医学   238篇
口腔科学   12篇
临床医学   267篇
内科学   324篇
皮肤病学   22篇
神经病学   110篇
特种医学   38篇
外科学   130篇
综合类   19篇
一般理论   7篇
预防医学   170篇
眼科学   8篇
药学   108篇
  1篇
肿瘤学   129篇
  2024年   2篇
  2023年   5篇
  2022年   23篇
  2021年   48篇
  2020年   22篇
  2019年   38篇
  2018年   47篇
  2017年   37篇
  2016年   42篇
  2015年   34篇
  2014年   48篇
  2013年   79篇
  2012年   138篇
  2011年   116篇
  2010年   76篇
  2009年   69篇
  2008年   114篇
  2007年   137篇
  2006年   129篇
  2005年   128篇
  2004年   88篇
  2003年   86篇
  2002年   70篇
  2001年   10篇
  2000年   7篇
  1999年   7篇
  1998年   16篇
  1997年   8篇
  1996年   9篇
  1995年   14篇
  1994年   12篇
  1993年   4篇
  1992年   2篇
  1991年   5篇
  1990年   2篇
  1989年   4篇
  1988年   2篇
  1987年   1篇
  1986年   3篇
  1985年   2篇
  1984年   1篇
  1979年   1篇
  1969年   1篇
  1968年   5篇
  1965年   1篇
  1926年   1篇
排序方式: 共有1694条查询结果,搜索用时 15 毫秒
1.

Background  

Exercise has been recommended for improving global-well being in adults with fibromyalgia. However, no meta-analysis has determined the effects of exercise on global well-being using a single instrument and when analyzed separately according to intention-to-treat and per-protocol analyses. The purpose of this study was to fill that gap.  相似文献   
2.
Incisional hernias occur in up to 17% of patients after liver transplantation. Laparoscopic ventral hernia repair is associated with fewer wound complications and a decreased incidence of recurrence when compared to open hernia repair in nontransplant patients. This is a retrospective review of 13 patients who underwent laparoscopic incisional hernia repair (LAP group) after liver transplantation compared to 14 patients who had open repairs (OP group; all but one with mesh). Primary immunosuppression in both groups at the time of transplantation was tacrolimus, but more patients in the LAP group were on sirolimus at the time of hernia, while more patients in the OP group were on prednisone at the time of hernia repair. All operations were completed with a laparoscopic approach; there were no conversions to open. Length of stay differed significantly between the 2 groups, with a mean of 5.4 days for the LAP group compared to 2.7 days in the OP group (0.0059). Complications occurred in 2 (15%) of the patients in the LAP group and 5 (36%) in the OP group. One patient in the LAP group required mesh removal to exclude causes of recurrent ascites, and 1 in the OP group for mesh infection. One (7.6%) of the patients in the LAP group developed a recurrence, compared to 29% (4) of the OP group (P =0.3259). In conclusion, laparoscopic incisional hernia repair is safe in patients after liver transplantation, with a low risk of infection or recurrence.  相似文献   
3.
4.
PURPOSE: Many preceptors fill out students' clerkship-performance forms with all items marked with the maximum value. Because items are usually designed to measure somewhat specific behaviors, the authors questioned the validity of straight-line five (SL5) responses, and conducted an empirical validity study to investigate the measurement properties of these SL5 forms. METHOD: In 1999-00 the authors undertook a correlation study and a generalizability study to assess the measurement characteristics of the SL5 forms. For the correlation study, they calculated mean scores for each of 168 students across forms, excluding the SL5 forms, then correlated this mean with the proportion of straight-line forms the student received. They conducted a generalizability analysis with and without the straight-line forms to determine the impact on score reliability. RESULTS: The proportion of SL5 forms was significantly correlated (r =.48, p <.0001) with the mean student score. Inclusion of the SL5 forms did not negatively affect the reliability of the mean score. CONCLUSION: The SL5 forms appear to be valid ratings of students' performances. An informal comparison of the comments on SL5 forms and those not displaying this format supported this conclusion.  相似文献   
5.
Rats treated with L-cocaine HCl exhibited an increase in hippocampal acetylcholine turnover, as measured by a mass fragmentographic technique. Furthermore, the ratio of hippocampal 3-methoxy-4-hydroxyphenylethyleneglycol to norepinephrine increased significantly. Possible mechanisms of the increased cholinergic activity are discussed.  相似文献   
6.
7.
Using an oddball stimulus presentation paradigm, the effects of divided attention on auditory P300s were studied. Auditory attention was either divided or focused, depending on the demands placed on subjects during the performance of a concomitantly presented visual task. Two types of auditory tasks were performed under each of the two auditory attention conditions. In one, subjects responded to infrequently presented high pitched tones (oddball stimuli). In the other they responded to the occasional omission of a stimulus in an otherwise rhythmically presented chain of stimuli. P300s and reaction times were recorded to both the rare tones and the omissions. The Sternberg visual memory task was used to manipulate the subject's auditory attention state. Subjects actively performed the Sternberg task during the divided auditory attention condition, whereas during the focused attention condition they were not required to respond to the visual stimuli. During focused auditory attention, evoked auditory P300s were both larger and faster than their emitted counterparts. During divided attention, auditory P300s were reduced in amplitude but latency was unaffected. Evoked auditory P300s showed evidence of containing P300a as well as P300b components, particularly when attention was shared with the visual task.  相似文献   
8.
Cell-extracted valvular tissues (acellular scaffolds, or aScaffolds) offer unique advantages over synthetic polymers for cardiac valve engineering applications in that they retain extracellular matrix molecules to support cellular ingrowth. The extracellular matrix is important in directing many cellular pathways, such as adhesion, proliferation, migration, differentiation, and survival. However, repopulating this type of scaffold often requires high seeding densities or recurrent cell delivery. The optimization of valvular interstitial cell (VIC) seeding onto aScaffolds is reported herein. VICs (the most prevalent cell type in valve leaflets) have maximal growth in 15-20% serum concentrations on tissue-culture polystyrene. Interestingly, after VIC seeding onto aScaffolds, a reduction of serum content, from 15% serum to 5% or less, was found to increase significantly the number of adherent cells, as well as induce transfer of VICs from a tissue-culture polystyrene surface to the aScaffold. aScaffolds seeded and cultured with periods of reduced serum levels were shown to support and enhance VIC viability and attachment, as well as accelerate VIC migration into the aScaffold, leading to a uniformly repopulated valve leaflet construct after 4 weeks of static culture.  相似文献   
9.
OBJECTIVES: To understand women's knowledge, attitudes and beliefs about prostate cancer. METHODS: A survey was self-administered to 324 women age >18 years. It contained 42 questions that assessed women's knowledge about prostate cancer, possible risk factors, and opinions regarding screening and early detection. Women were grouped as married or unmarried for convenient comparisons. Chi-squared and F statistics were performed. RESULTS: Ninety-seven percent of married women reported having some influence over the healthcare decisions of their spouse. Married women's worst fear about their spouse or family member's diagnosis of prostate cancer was death. The most important benefit of prostate cancer screening was the possibility of cure, while the main hindrance was fear of the digital rectal exam. Marital status, age, educational level and income were all significantly associated with women's knowledge about prostate cancer (p<0.001). CONCLUSIONS: Women play an important role in health-related matters in the home. Educating women on prostate cancer may improve early detection efforts and reduce the devastating impact of this disease on their family.  相似文献   
10.
In developing a scaffold to support new tissue growth, the degradation rate and mass loss profiles of the scaffold are important design parameters. In this study, hydrogels were prepared by copolymerizing a degradable macromer, poly(lactic acid)-b-poly(ethylene glycol)-b-poly(lactic acid) endcapped with acrylate groups (PEG-LA-DA) with a nondegradable macromer, poly(ethylene glycol) dimethacrylate (PEGDM). The resulting hydrogels exhibited a range of degradation behavior and mass loss profiles. Chondrocytes were photoencapsulated in gels formulated with 50:50, 25:75, and 15:85 (mol % PEGDM: mol % PEG-LA-DA) and cultured for 6 weeks in vitro. The neocartilaginous tissue formed was examined biochemically and histologically. After 6 weeks, the DNA content in gels with 75 and 85% degradable crosslinks was nearly twice that of the DNA content in the 50% gels. The total collagen content was significantly higher in the 85% gel [2.4 +/- 0.8% wet weight (ww)] compared to the 50% gel (0.22 +/- 0.29% ww). In examining the neocartilaginous tissue with immunohistochemistry, type II collagen was localized in the pericellular region in the 50% gel; however, when increased degradation was incorporated into the gel, type II collagen was found throughout the neotissue. In summary, the important role of hydrogel degradation in controlling and influencing the deposition and distribution of extracellular matrix molecules was demonstrated and quantified.  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