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   2926篇
  免费   173篇
  国内免费   16篇
耳鼻咽喉   42篇
儿科学   53篇
妇产科学   51篇
基础医学   342篇
口腔科学   41篇
临床医学   231篇
内科学   851篇
皮肤病学   67篇
神经病学   135篇
特种医学   167篇
外科学   415篇
综合类   20篇
预防医学   63篇
眼科学   50篇
药学   279篇
中国医学   8篇
肿瘤学   300篇
  2023年   26篇
  2022年   35篇
  2021年   40篇
  2020年   42篇
  2019年   43篇
  2018年   80篇
  2017年   51篇
  2016年   62篇
  2015年   58篇
  2014年   82篇
  2013年   73篇
  2012年   178篇
  2011年   135篇
  2010年   108篇
  2009年   81篇
  2008年   167篇
  2007年   133篇
  2006年   143篇
  2005年   147篇
  2004年   136篇
  2003年   148篇
  2002年   137篇
  2001年   76篇
  2000年   77篇
  1999年   101篇
  1998年   32篇
  1997年   39篇
  1996年   32篇
  1995年   20篇
  1994年   15篇
  1993年   21篇
  1992年   73篇
  1991年   59篇
  1990年   57篇
  1989年   42篇
  1988年   42篇
  1987年   39篇
  1986年   46篇
  1985年   37篇
  1984年   29篇
  1983年   23篇
  1982年   10篇
  1981年   16篇
  1980年   12篇
  1979年   17篇
  1978年   13篇
  1977年   13篇
  1975年   9篇
  1973年   6篇
  1969年   12篇
排序方式: 共有3115条查询结果,搜索用时 15 毫秒
81.
82.
83.
Pediatric Surgery International - Human breast milk (HBM), which contains an abundant supply of exosomes, is known to prevent necrotizing enterocolitis (NEC). Preterm infants are commonly given...  相似文献   
84.
Background Although a second hepatic resection (SHR) for recurrent hepatocellular carcinoma (HCC) is widely accepted, the indications for SHR have not been established. The risk factors for HCC recurrence after SHR were evaluated to investigate the indications for SHR. Methods Subjects included 51 patients who underwent a second hepatic resection for recurrence of HCV-related HCC. Sixteen patients received interferon therapy before or after the first operation. Six patients attained a sustained viral response (SVR) that was defined as return of the alanine aminotransferase (ALT) activity to within the reference range and no detectable serum HCV RNA for at least 1 year after interferon therapy. A biochemical response (BR), defined as a normalized ALT activity for at least 1 year after interferon therapy with or without the transient disappearance of serum HCV RNA, was attained in three patients. The other seven patients were defined as the nonresponse (NR) group. Results By univariate analysis, NR and lack of interferon therapy, high indocyanine green retention rate at 15 min (ICGR15), high aspartate aminotransferase activity, high ALT activity, large tumor, and multiple tumors were risk factors for HCC recurrence after SHR. By multivariate analysis, NR and lack of interferon therapy, high ICGR15, large tumor, and multiple tumors were independent risk factors. Conclusions Patients in whom active hepatitis has been controlled by interferon therapy are the best candidates for SHR. Interferon therapy should be recommended in patients undergoing resection of an HCV-related HCC because SHR can prolong life in SVR and BR patients.  相似文献   
85.
(1) Background: Protein stimulates the secretion of glucagon (GCG), which can affect glucose metabolism. This study aimed to analyze the metabolic effect of a high-protein diet (HPD) in the presence or absence of proglucagon-derived peptides, including GCG and GLP-1. (2) Methods: The response to HPD feeding for 7 days was analyzed in mice deficient in proglucagon-derived peptides (GCGKO). (3) Results: In both control and GCGKO mice, food intake and body weight decreased with HPD and intestinal expression of Pepck increased. HPD also decreased plasma FGF21 levels, regardless of the presence of proglucagon-derived peptides. In control mice, HPD increased the hepatic expression of enzymes involved in amino acid metabolism without the elevation of plasma amino acid levels, except branched-chain amino acids. On the other hand, HPD-induced changes in the hepatic gene expression were attenuated in GCGKO mice, resulting in marked hyperaminoacidemia with lower blood glucose levels; the plasma concentration of glutamine exceeded that of glucose in HPD-fed GCGKO mice. (4) Conclusions: Increased plasma amino acid levels are a common feature in animal models with blocked GCG activity, and our results underscore that GCG plays essential roles in the homeostasis of amino acid metabolism in response to altered protein intake.  相似文献   
86.
87.
Here we report a case of spinal dural areteriovenous fistula (AVF) draining to the anterior spinal vein. An 80-year-old female presented with progressive weakness of lower extremities. MRI showed spinal enlargement at the Th10 to L1 with high intensity signals on T2-weighted image and multiple flow voids on the dorsal and ventral surface of the spinal cord. Angiogram of the left L2 lumbar artery demonstrated a hairpin-shaped vessel with ascending and descending limbs, mimicking radiculomedullary artery. Oblique view angiogram of the left L2 lumbar artery showed that radiculomedullary vein drained to the dilated anterior spinal vein, which then drained cranially and caudally on the anterior and posterior surface of the spinal cord. The patient underwent T9-L2 laminectomy. Several large tortuous dilated veins in the subarachnoid space were found. Examination of the inner surface of the dura revealed an arterialized vein that began at the level of L2 and coursed superiorly. The arterialized vein was coagulated and interrupted. The postoperative angiogram demonstrated the obliteration of the fistula. Postoperative MRI returned to normal with complete disappearance of T2 high signal, cord enlargement. In most spinal dural AVF, the venous drainage is predominantly upward on the posterior surface of the spinal cord. The spinal dural AVF draining to the anterior spinal vein is atypical, and cause difficulty in differentiating the anterior spinal artery from the anterior spinal vein. Oblique view angiogram may be helpful to differentiate the anterior spinal vein from anterior spinal artery.  相似文献   
88.
The objective of this study was to clarify the roles of anti-phospholipid antibodies (aPLs) in the pathogenesis of acquired activated protein C resistance (APC-R) in patients with systemic lupus erythematosus (SLE). We examined several aPLs levels (lupus anticoagulant, anti-cardiolipin antibodies, anti-β2-glycoprotein I antibodies, anti-protein C antibodies, and anti-protein S antibodies), the APC-R test, and the factor V Leiden test in 85 SLE patients. Acquired APC-R, which was not found in any patient with the factor V Leiden mutation, was present in 26 (30.6%) of 85 patients, and confirmed that acquired APC-R was a significant risk factor for thromboembolic complications [odd ratio (OR), 3.36; 95% confidence interval (CI), 1.24-9.11]. Multivariate logistic analysis revealed that both LA and anti-PS strongly associated with the presence of APC-R, and that the correlation between anti-PS and APC-R was much stronger (OR, 46.7; 95%CI, 6.99-311) than that between LA and APC-R (OR, 11.3; 95%CI, 2.26-57.0). Furthermore, the mean value of APC sensitivity ratios was significantly lower in SLE patients with anti-PS (mean ± SD, 1.68 ± 0.37, p < 0.0001) than in those without anti-PS (2.23 ± 0.40). These results suggest that acquired APC-R is most strongly attributable to functional interference of the APC pathway by anti-PS, which contribute to risk of thromboembolic complications.  相似文献   
89.
Venlafaxine has potential as a therapeutic option for patients with depressive disorder, migraine, and pruritus unresponsive to antihistamines.  相似文献   
90.

Objective  

Recently, guidelines for the treatment and prevention of ulcers induced by non-steroidal anti-inflammatory drugs (NSAIDs) were established. This study investigated the association between the current adherence to the guidelines and the incidence of gastric mucosal lesions caused by NSAIDs.  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