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   1706篇
  免费   87篇
  国内免费   6篇
耳鼻咽喉   34篇
儿科学   134篇
妇产科学   215篇
基础医学   119篇
口腔科学   25篇
临床医学   129篇
内科学   380篇
皮肤病学   28篇
神经病学   104篇
特种医学   58篇
外科学   299篇
综合类   34篇
一般理论   1篇
预防医学   39篇
眼科学   33篇
药学   88篇
中国医学   5篇
肿瘤学   74篇
  2023年   13篇
  2022年   23篇
  2021年   24篇
  2020年   19篇
  2019年   26篇
  2018年   50篇
  2017年   32篇
  2016年   49篇
  2015年   52篇
  2014年   57篇
  2013年   97篇
  2012年   118篇
  2011年   121篇
  2010年   63篇
  2009年   62篇
  2008年   124篇
  2007年   151篇
  2006年   123篇
  2005年   139篇
  2004年   116篇
  2003年   113篇
  2002年   88篇
  2001年   37篇
  2000年   26篇
  1999年   26篇
  1998年   5篇
  1997年   2篇
  1996年   1篇
  1995年   3篇
  1994年   1篇
  1993年   1篇
  1992年   7篇
  1991年   3篇
  1990年   3篇
  1989年   5篇
  1988年   6篇
  1987年   4篇
  1986年   1篇
  1985年   4篇
  1982年   1篇
  1975年   1篇
  1968年   1篇
  1966年   1篇
排序方式: 共有1799条查询结果,搜索用时 0 毫秒
81.
The Pregenesys Consensus Meeting held in Cambridge on 13 July 2009 was organized by the Pregenesys Consortium to review and critically discuss current knowledge regarding early markers of preeclampsia, to identify priorities and opportunities for future research, to consider issues that may need to be addressed in future recommendations and to highlight key issues in cost effectiveness and national policies concerning prediction and early screening for the risk of developing preeclampsia.This report summarizes the outcome of the Consensus Meeting and draws attention to issues for further investigation with specific regard to single versus multiple markers, early versus late risk identification, and the long-term effects on both maternal and perinatal health and the need to include these in any future cost-benefit assessment.  相似文献   
82.
Although varicella is a benign self-limiting disease in healthy children, it can be fatal when it occurs in immunocompromised hosts. Despite that immunosuppressed children are suggested to require 2 doses of vaccine to achieve seroconversion, conflicting results are reported in the literature. The aim of this study was to investigate the seroconversion status and mean antibody titers at first year after single dose and double doses of varicella vaccination in acute lymphoblastic leukemia patients. Patients with leukemia in remission for at least 1 year who were seronegative for varicella-zoster virus immunoglobulin G (IgG) were vaccinated. Titers above the cutoff level (0.65) were accepted as seroconversion. Seventeen patients were vaccinated with single dose whereas 24 patients were vaccinated with double doses. Mean prevaccination antibody titers were 0.56 ± 0.05 in patients with single dose and 0.51 ± 0.08 in patients with double doses (P > .05, Student t test). The mean antibody titers at first year were 0.61 ± 0.05 in patients with single-dose vaccination (P > .05, Wilcoxon signed-rank test) and 1.48 ± 0.04 in patients with double doses (P < .001, Wilcoxon signed-rank test). Seroconversion after single-dose vaccination was achieved in 29% of patients (n = 5/17) and in 75% of patients with double doses (n = 18/24) at first year (P = .004, chi-square test). These results suggest that seroconversion after single-dose vaccination might not persist at first year in malignancy patients. Double doses should be applied in order to provide long-term seroconversion.  相似文献   
83.
An 83‐year‐old male patient presented to the outpatient clinic with complaint of swelling at right antecubital area. Ultrasonographic examination of the right upper extremity revealed a mass lesion within the right cephalic vein, which was consistent with thrombus. A computed tomography (CT) venography showed contrast enhancement in cephalic vein at distal arm and an aneurysmatic thrombus area displaying regular borders with a size of 28*30 mm; there was no contrast enhancement at more proximal levels at the cephalic vein.  相似文献   
84.
The aim of this study was to evaluate left atrial deformations using speckle tracking echocardiography for predicting left atrial appendage (LAA) thrombus in patients with suspected cardioembolic stroke who were in normal sinus rhythm. A total of 153 ischemic stroke patients (89 males, 64 females) in sinus rhythm who were suspected of having cardioembolism were included in the study. The patients underwent conventional two‐dimensional (2D) echocardiogram and 2D speckle tracking echocardiogram of the left atrium. Left atrial peak strain (LA‐4C‐RES) and left atrial precontraction strain (LA‐4C‐PUMP) were measured. Patients were divided into 2 groups according to the presence of thrombus in the LAA in transesophageal echocardiography. Both LA‐4C‐RES and LA‐4C‐PUMP values were found to be significantly lower in patients with LAA thrombus (11.8 ± 1.4% vs. 33 ± 12%, P < 0.001 and 5.8 ± 1.3% vs. 14.2 ± 5.3%, P < 0.001, respectively). A good inverse correlation was present between LA‐4C‐RES values and LAA morphologic parameters (with LAA area: r = ?0.70, P < 0.001, with LAA length: r = ?0.60, P < 0.001), and a good positive correlation was present with LAA emptying velocity with pulse Doppler (r = 0.74, P < 0.001). The area under the receiver‐operating characteristic curve of the LA‐4C‐RES was 0.94 (0.90–0.98, P < 0.001), for the LA‐4C‐PUMP, the area was 0.92 (0.87–0.96, P < 0.001) to predict LAA thrombus. Left atrial deformation parameters measured by 2D speckle tracking method was found to predict impaired LAA functions and the presence of LAA thrombus in ischemic stroke patients with suspected cardioembolism, but who are in sinus rhythm.  相似文献   
85.
86.
A three-month-old boy presented with growth failure, skeletal abnormalities, otitis media and pancytopenia. Exocrine pancreatic insufficiency was confirmed by low levels of fecal elastase. He was diagnosed as Shwachman-Diamond syndrome by clinical and laboratory findings. The diagnosis was confirmed by sequence analysis for SBDS gene on chromosome seven revealing compound heterozygous mutation, which are c.258+2T-C and c.183-184TA-CT. Matched unrelated donor screening for hematopoietic stem cell transplantation was initiated. Unfortunately, he died of respiratory difficulty at 5 months of age. Our case is the youngest patient whose presumptive Shwachman-Diamond syndrome diagnosis was confirmed by molecular analysis.  相似文献   
87.
Anaphylaxis and acute allergic reactions may sometimes be fatal. They occur within minutes in a sensitized individual. So quick diagnosis and management are necessary issues. In the literature, cases are widely reported against allergens found in drugs, foods and their additives, radiocontrast material, bee stings, and many other materials. Here, we present a 37-year-old woman who developed an anaphylactic reaction to normal saline infusion during evaluation for her acute abdominal pain. We found only one report about normal saline allergy in the literature (Litvin ME, Shemchuck AS, Lisetskii VA. Anaphylactic shock caused by intravenous injection of isotonic solution of sodium chloride. Klin Khir 1976;(7):59-61).  相似文献   
88.
89.
Giant Cervical Polyp Due to a Foreign Body in a ''Virgin''   总被引:1,自引:0,他引:1  
A 17-year-old virgin who had a giant cervical polyp which had developed through a foreign body and protruded out of the hymen was evaluated; the aetiological significance of the foreign body in the formation of the cervical polyp is discussed.  相似文献   
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