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   20346篇
  免费   3501篇
  国内免费   288篇
耳鼻咽喉   754篇
儿科学   644篇
妇产科学   380篇
基础医学   1302篇
口腔科学   656篇
临床医学   2360篇
内科学   4789篇
皮肤病学   742篇
神经病学   1654篇
特种医学   844篇
外科学   4426篇
综合类   222篇
现状与发展   2篇
一般理论   5篇
预防医学   1358篇
眼科学   834篇
药学   1048篇
中国医学   52篇
肿瘤学   2063篇
  2023年   555篇
  2022年   242篇
  2021年   544篇
  2020年   860篇
  2019年   392篇
  2018年   901篇
  2017年   782篇
  2016年   968篇
  2015年   944篇
  2014年   1265篇
  2013年   1460篇
  2012年   944篇
  2011年   921篇
  2010年   946篇
  2009年   1169篇
  2008年   772篇
  2007年   673篇
  2006年   787篇
  2005年   608篇
  2004年   532篇
  2003年   485篇
  2002年   449篇
  2001年   463篇
  2000年   414篇
  1999年   393篇
  1998年   351篇
  1997年   335篇
  1996年   384篇
  1995年   354篇
  1994年   222篇
  1993年   176篇
  1992年   285篇
  1991年   294篇
  1990年   227篇
  1989年   262篇
  1988年   236篇
  1987年   242篇
  1986年   224篇
  1985年   197篇
  1984年   200篇
  1983年   150篇
  1982年   126篇
  1980年   101篇
  1979年   95篇
  1978年   91篇
  1977年   101篇
  1976年   90篇
  1975年   100篇
  1974年   102篇
  1972年   86篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Migraine is a complex disorder that is characterized by an assortment of neurological and systemic effects. While headache is the most prominent feature of migraine, a host of symptoms affecting many physiological functions are also observed before, during, and after an attack. Furthermore, migraineurs are heterogeneous and have a wide range of responses to migraine therapies. The recent approval of calcitonin gene-related-peptide based therapies has opened up the treatment of migraine and generated a renewed interest in migraine research and discovery. Ongoing advances in migraine research have identified a number of other promising therapeutic targets for this disorder. In this review, we highlight emergent treatments within the following biological systems: pituitary adenylate cyclase activating peptdie, 2 non-mu opioid receptors that have low abuse liability – the delta and kappa opioid receptors, orexin, and nitric oxide-based therapies. Multiple mechanisms have been identified in the induction and maintenance of migraine symptoms; and this divergent set of targets have highly distinct biological effects. Increasing the mechanistic diversity of the migraine tool box will lead to more treatment options and better patient care.  相似文献   
993.
994.
995.
Splenosis is an unusual condition representing auto-transplantation of splenic tissue following splenic trauma or surgery. When detected on imaging studies, the splenosis deposits are usually misinterpreted as pathological masses. We present a case where a pelvic mass incidentally visualized on an MRI examination, was proven to represent a deposit of splenosis by contrast enhanced ultrasound (CEUS). CEUS demonstrated persistent late-phase enhancement characteristic of splenic tissue. Ultrasound practitioners should be aware of this condition when an unusual abdominal or pelvic mass is encountered in a patient with a history of splenic trauma or surgery. CEUS is ideally suited to confirming the diagnosis.  相似文献   
996.
We present a case of an 89‐year‐old man with a left ventricular assist device and cardiac resynchronization therapy device (CRT‐D) who presented with multiple presyncopal events. On the night of admission, telemetry revealed a 13‐s pause with appropriately timed pacing spikes but with failure to capture, followed by intermittent ventricular contraction with different QRS morphology. What was the mechanism for his ventricular asystole?  相似文献   
997.
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - A purple non sulphur phototrophic bacterium (PNSB) Rhodobacter sp. GSKRLMBKU–03 was isolated from pond...  相似文献   
998.
A patient with combined folate and B12 deficiency due to tropical sprue failed to respond to the administration of N5-methyltetrahydrofolate when given by mouth or intravenously. After the injection of 1 μg of B12 intravenously the patient became asymptomatic and laboratory tests returned to normal. Failure of response to N5-methyltetrahydrofolate in the presence of B12 deficiency is evidence in favor of the “folate trap” hypothesis.  相似文献   
999.
1000.
Severe graft disease occurs in patients at a rate of approximately 15% within the first year of coronary artery bypass grafting (CABG). In this study, the authors examined predictors of the combined end point of death, nonfatal myocardial infarction (MI), and bypass graft disease at 2-year follow-up after CABG. One hundred twenty-one consecutive patients were included in this study after informed consent was obtained. In univariate analysis, there was a significantly (P<.05) higher homocysteine level (11.0 ng/mol vs 9.7 ng/mol, P=.04) in patients who met the combined end point vs those who did not. There were no statistically significant differences in the following: low-density lipoprotein cholesterol, high-sensitivity C-reactive protein, and lipoprotein(a) values; age; body mass index; smoking and diabetes status; statin or aspirin use; creatinine level; hematologic markers; left ventricular ejection fraction; number of bypass grafts; and distribution of coronary artery disease. Logistic regression analysis modeling for low-density lipoprotein cholesterol, lipoprotein(a), fibrinogen, and homocysteine showed that homocysteine value (P=.016) was an independent predictor of the primary combined end point.  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