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   3312993篇
  免费   266479篇
  国内免费   6974篇
耳鼻咽喉   47306篇
儿科学   104759篇
妇产科学   91047篇
基础医学   463818篇
口腔科学   97570篇
临床医学   301951篇
内科学   649493篇
皮肤病学   71322篇
神经病学   278811篇
特种医学   129409篇
外国民族医学   1198篇
外科学   495051篇
综合类   79212篇
现状与发展   5篇
一般理论   1370篇
预防医学   272333篇
眼科学   78177篇
药学   241641篇
  5篇
中国医学   6999篇
肿瘤学   174969篇
  2019年   26859篇
  2018年   37521篇
  2017年   28706篇
  2016年   31440篇
  2015年   35696篇
  2014年   51180篇
  2013年   76686篇
  2012年   104214篇
  2011年   110239篇
  2010年   64473篇
  2009年   61274篇
  2008年   102220篇
  2007年   108518篇
  2006年   109052篇
  2005年   106423篇
  2004年   102064篇
  2003年   97902篇
  2002年   94580篇
  2001年   152271篇
  2000年   156849篇
  1999年   132208篇
  1998年   39052篇
  1997年   35324篇
  1996年   34958篇
  1995年   33455篇
  1994年   31145篇
  1993年   29246篇
  1992年   104256篇
  1991年   100225篇
  1990年   96483篇
  1989年   92794篇
  1988年   86093篇
  1987年   84652篇
  1986年   79825篇
  1985年   76287篇
  1984年   58228篇
  1983年   49586篇
  1982年   30389篇
  1981年   27039篇
  1979年   53809篇
  1978年   37966篇
  1977年   31849篇
  1976年   29919篇
  1975年   31213篇
  1974年   38343篇
  1973年   36638篇
  1972年   34351篇
  1971年   31588篇
  1970年   29913篇
  1969年   27837篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Dosage form is a mean used for the delivery of drug to a living body. In order to get the desired effect the drug should be delivered to its site of action at such rate and concentration to achieve the maximum therapeutic effect and minimum adverse effect. Since oral route is still widely accepted route but having a common drawback of difficulty in swallowing of tablets and capsules. Therefore a lot of research has been done on novel drug delivery systems. This review is about oral dispersible tablets a novel approach in drug delivery systems that are now a day''s more focused in formulation world, and laid a new path that, helped the patients to build their compliance level with the therapy, also reduced the cost and ease the administration especially in case of pediatrics and geriatrics. Quick absorption, rapid onset of action and reduction in drug loss properties are the basic advantages of this dosage form.  相似文献   
83.
Pediatric trachyonychia is an acquired nail disease that can cause distress to families. It is a poorly understood disease, and long‐term follow‐up data are lacking. We present an institutional review of 11 children with isolated pediatric trachyonychia followed over time. Children with the diagnosis of pediatric trachyonychia were identified and invited to participate. Pictures were taken on follow‐up and a questionnaire was answered. Exclusion criteria include having another diagnosis at the initial visit that causes nail dystrophy. Eleven patients with the diagnosis of pediatric trachyonychia were available for follow‐up. The mean age of appearance was 2.7 years (range 2–7 yrs) and the average follow‐up was 66 months (range 10–126 mos). Nine patients were treated with potent topical corticosteroids, one used only petrolatum, and one took vitamin supplements. One patient was found to have an additional skin and hair diagnosis of alopecia areata on follow‐up. On follow‐up, 82% noted improvement of the nails, whereas 18% noted no change. A majority of cases of pediatric trachyonychia are isolated and improve with time, regardless of treatment.  相似文献   
84.
85.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
86.
87.
Bipolar disorder (BD) is a common psychiatric mood disorder affecting more than 1-2% of the general population of different European countries. Unfortunately, there is no objective laboratory-based test to aid BD diagnosis or monitor its progression, and little is known about the molecular basis of BD. Here, we performed a comparative proteomic study to identify differentially expressed plasma proteins in various BD mood states (depressed BD, manic BD, and euthymic BD) relative to healthy controls. A total of 10 euthymic BD, 20 depressed BD, 15 manic BD, and 20 demographically matched healthy control subjects were recruited. Seven high-abundance proteins were immunodepleted in plasma samples from the 4 experimental groups, which were then subjected to proteome-wide expression profiling by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight tandem mass spectrometry. Proteomic results were validated by immunoblotting and bioinformatically analyzed using MetaCore. From a total of 32 proteins identified with 1.5-fold changes in expression compared with healthy controls, 16 proteins were perturbed in BD independent of mood state, while 16 proteins were specifically associated with particular BD mood states. Two mood-independent differential proteins, apolipoprotein (Apo) A1 and Apo L1, suggest that BD pathophysiology may be associated with early perturbations in lipid metabolism. Moreover, down-regulation of one mood-dependent protein, carbonic anhydrase 1 (CA-1), suggests it may be involved in the pathophysiology of depressive episodes in BD. Thus, BD pathophysiology may be associated with early perturbations in lipid metabolism that are independent of mood state, while CA-1 may be involved in the pathophysiology of depressive episodes.  相似文献   
88.
Hepatic NADPH-cytochrome P450 oxidoreductase null (HRN?) mice exhibit normal hepatic and extrahepatic biotransformation enzyme activities when compared to wild-type (WT) mice, but express no functional hepatic cytochrome P450 activities. When incubated in vitro with [14C]-diclofenac, liver microsomes from WT mice exhibited extensive biotransformation to oxidative and glucuronide metabolites and covalent binding to proteins was also observed. In contrast, whereas glucuronide conjugates and a quinone-imine metabolite were formed when [14C]-diclofenac was incubated with HRN? mouse liver, only small quantities of P450-derived oxidative metabolites were produced in these samples and covalent binding to proteins was not observed. Livers from vehicle-treated HRN? mice exhibited enhanced lipid accumulation, bile duct proliferation, hepatocellular degeneration and necrosis and inflammatory cell infiltration, which were not present in livers from WT mice. Elevated liver-derived alanine aminotransferase, glutamate dehydrogenase and alkaline phosphatase activities were also observed in plasma from HRN? mice. When treated orally with diclofenac for 7 days, at 30 mg/kg/day, the severities of the abnormal liver histopathology and plasma liver enzyme findings in HRN? mice were reduced markedly. Oral diclofenac administration did not alter the liver histopathology or elevate plasma enzyme activities of WT mice. These findings indicate that HRN? mice are valuable for exploration of the role played by hepatic P450s in drug biotransformation, but poorly suited to investigations of drug-induced liver toxicity. Nevertheless, studies in HRN? mice could provide novel insights into the role played by inflammation in liver injury and may aid the evaluation of new strategies for its treatment.  相似文献   
89.
90.
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