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   181058篇
  免费   1310篇
  国内免费   58篇
耳鼻咽喉   1262篇
儿科学   6830篇
妇产科学   3073篇
基础医学   17189篇
口腔科学   1676篇
临床医学   12647篇
内科学   32465篇
皮肤病学   745篇
神经病学   16706篇
特种医学   9259篇
外科学   29809篇
综合类   2334篇
一般理论   1篇
预防医学   18141篇
眼科学   2836篇
药学   9715篇
中国医学   636篇
肿瘤学   17102篇
  2023年   61篇
  2022年   130篇
  2021年   259篇
  2020年   116篇
  2019年   191篇
  2018年   22080篇
  2017年   17504篇
  2016年   19652篇
  2015年   1070篇
  2014年   1017篇
  2013年   1047篇
  2012年   7397篇
  2011年   21428篇
  2010年   19022篇
  2009年   11661篇
  2008年   19793篇
  2007年   22023篇
  2006年   903篇
  2005年   2564篇
  2004年   3668篇
  2003年   4692篇
  2002年   2829篇
  2001年   309篇
  2000年   440篇
  1999年   227篇
  1998年   287篇
  1997年   263篇
  1996年   153篇
  1995年   167篇
  1994年   142篇
  1993年   116篇
  1992年   73篇
  1991年   112篇
  1990年   141篇
  1989年   98篇
  1988年   70篇
  1987年   47篇
  1986年   27篇
  1985年   37篇
  1984年   27篇
  1983年   29篇
  1982年   30篇
  1980年   50篇
  1974年   22篇
  1938年   60篇
  1937年   25篇
  1935年   22篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
991.
A young male patient presented with multiple swellings on his chest and the nape of his neck. Physical examination revealed multiple small papulonodular swellings measuring 0.5?×?0.5 cm to 2?×?2 cm, that were soft without discharge with no surrounding skin changes or induration. Skin biopsy samples were diagnosed as benign adnexal neoplasm consistent with eccrine spiradenoma, trichoepithelioma, and cylindroma, i.e., Brooke–Spiegler syndrome. Having confirmed this to be a case of eccrine spiradenoma, surgical excision was performed and the raw area was covered with a split thickness skin graft taken from the right thigh and sutured over the raw area. The sternal lesion was circumferentially excised and the wound was primarily closed by Z-plasty. Surgical excision is considered the gold standard for the treatment of these cases, with low rates of recurrence. Around 50 such cases have been reported in the literature to date. Although eccrine spiradenomas are usually solitary and small, the findings in our case underscore the fact that a variety of presentations are possible. With strict clinical suspicion and histological criteria, the correct diagnosis can be achieved, especially when combined with pertinent clinical information and laboratory studies.Level of Evidence: Level V, therapeutic study.  相似文献   
992.
Not only does erectile dysfunction (ED) reflect penile vascular disorder in the majority of patients, but it also implicates their high systemic cardiovascular risk. Based on the principle of reactive hyperemia after a brief period of penile ischemia, in this study, we tested the validity of a new Penile Arterial Waveform Analyzer (PAWA) in assessing the relative increase in post-ischemic penile perfusion. Twenty young adult males (mean age 24.24 ± 2.45) without known history of cardiovascular diseases were recruited, whose anthropometric characteristics were recorded and their serum testosterone levels as well as biochemical profiles were determined. A penile cuff was applied to each subject, with cuff pressure being increased from 80 to 250 mmHg, each for 4 min, followed by reperfusion for 7 min. By dividing the area under waveform contour of hyperemic and baseline signals after Ensemble Empirical Mode Decomposition (EEMD), a Penile Perfusion Index (PPI) was calculated. Penile Brachial Index (PBI) was also obtained for comparison. The results not only showed a significant agreement between PPI and serum testosterone levels, but also a superiority of PPI to PBI in distinguishing the high- and low-risk groups for potential ED (PPI: p = 0.039 vs. PBI: p = 0.147). PPI was also demonstrated to show significant correlations with waist circumference (p < 0.001), body mass index (p = 0.005), body weight, total triglyceride, high-density lipoprotein, and systolic and diastolic pressures (all p < 0.05). In conclusion, we proposed a portable and easy-to-operate system in assessing the relative increase in penile perfusion after brief ischemia. The PPI thus obtained correlated significantly with serum testosterone levels as well as key anthropometric and serum biochemical parameters even in apparently healthy young adults, suggesting its potential as a sensitive tool in monitoring penile vascular function and risk for ED.  相似文献   
993.

Objectives  

This study aimed to compare the tolerability and efficacy of two different titrations of paroxetine (slow and standard) in a population of cancer patients with depression.  相似文献   
994.
The present article, dedicated to Dr NS Dhalla on the occasion of the jubilee of his life’s work, is a brief review of articles based on the authors’ studies of sarpogrelate conducted in collaboration with Dr NS Dhalla. These studies on the effects of sarpogrelate on cardiovascular disorders have been ongoing for more than 10 years, and 10 articles have been published to date.  相似文献   
995.
996.

Background  

Ergosterol peroxide (EP) derived from edible mushroom has been shown to exert anti-tumor activity in several cancer cells. In the present study, anti-angiogenic activity of EP was investigated with the underlying molecular mechanisms in human multiple myeloma U266 cells.  相似文献   
997.

Background  

Curcumin (diferuloylmethane), the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC), is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C) which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy.  相似文献   
998.
Rigid cognition is frequently cited as a plausible maintenance or risk factor for depression. However, most performance-based measures of cognitive rigidity associated with depression offer poor ecological validity, produce mixed findings, and afford little in the way of therapeutic application. In order to establish a more useful and relevant performance-based measure of cognitive rigidity in depression, we developed a novel task that probes a rigidity process using stimuli highly relevant to the level of construal, the thematic content, and the rhetorical mode of depressotypic thinking. The task consists of a set of narrative vignettes that contain an expectancy-violation that is incompatible with an initially-established interpretation. As hypothesized, depressive symptoms were associated with reduced ability to update interpretations. This finding was independent of the valence of the expectancy-violation (i.e., was not merely a negativity bias), and was significant after controlling for basic set-shifting ability, intelligence measures, working memory, and other potential confounds. The novel Contingent Inference Task is a promising approach that may probe a more ecologically and etiologically relevant form of cognitive rigidity in depression than other related performance-based rigidity tasks. This rigidity process may underlie the persistence of biased beliefs in depression, and represent a new therapeutic target.  相似文献   
999.
Conventional peer review practice is compromised by a number of well-documented biases, which in turn limit standard of care analysis, which is fundamental to determination of medical malpractice. In addition to these intrinsic biases, other existing deficiencies exist in current peer review including the lack of standardization, objectivity, retrospective practice, and automation. An alternative model to address these deficiencies would be one which is completely blinded to the peer reviewer, requires independent reporting from both parties, utilizes automated data mining techniques for neutral and objective report analysis, and provides data reconciliation for resolution of finding-specific report differences. If properly implemented, this peer review model could result in creation of a standardized referenceable peer review database which could further assist in customizable education, technology refinement, and implementation of real-time context and user-specific decision support.  相似文献   
1000.
Blunt abdominal trauma mostly results from motor vehicle accidents, recreational accidents, falls or assaults with commonly injured internal organs being the spleen, liver, retroperitoneum, small bowel, kidneys, bladder, colorectal, diaphragm and pancreas. Gastric rupture is quite uncommon. Isolated gastric perforations following blunt trauma to the abdomen are mostly seen in paediatric patients. It is uncommon in adult patients and even rarer is the occurrence of double gastric perforations. We report here with a case of isolated double gastric perforation in a 24-year-old male patient following vehicular accident.  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