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   831篇
  免费   21篇
  国内免费   7篇
耳鼻咽喉   7篇
儿科学   63篇
妇产科学   29篇
基础医学   97篇
口腔科学   32篇
临床医学   62篇
内科学   181篇
皮肤病学   24篇
神经病学   29篇
特种医学   16篇
外科学   175篇
综合类   8篇
一般理论   2篇
预防医学   12篇
眼科学   26篇
药学   42篇
肿瘤学   54篇
  2023年   4篇
  2022年   8篇
  2021年   13篇
  2020年   9篇
  2019年   4篇
  2018年   14篇
  2017年   9篇
  2016年   6篇
  2015年   19篇
  2014年   18篇
  2013年   19篇
  2012年   39篇
  2011年   58篇
  2010年   27篇
  2009年   24篇
  2008年   63篇
  2007年   64篇
  2006年   81篇
  2005年   117篇
  2004年   98篇
  2003年   56篇
  2002年   37篇
  2001年   14篇
  2000年   9篇
  1999年   15篇
  1998年   2篇
  1997年   1篇
  1995年   3篇
  1992年   2篇
  1990年   1篇
  1989年   1篇
  1988年   7篇
  1987年   4篇
  1986年   1篇
  1985年   2篇
  1984年   2篇
  1983年   1篇
  1980年   1篇
  1978年   2篇
  1977年   1篇
  1975年   1篇
  1970年   1篇
  1909年   1篇
排序方式: 共有859条查询结果,搜索用时 0 毫秒
61.
A case of postoperative large anterior staphyloma of the sclera was treated with a dehydrated cadaveric dura mater patch graft. Structural integrity of the globe and a good cosmetic result were obtained after the surgery. During the follow-up of 2 years, no recurrence of staphyloma developed.  相似文献   
62.
We have treated a 33-year-old Budd-Chiari patient (due to antiphospholipid syndrome) with a history of myocardial infarction by placing a vascular stent in the inferior vena cava and performing a portorenal shunt with three objectives: (1) to perform a shunt operation on a Budd-Chiari patient with good hepatic functional reserve, (2) to avoid a thoracotomy and manipulation of the heart in a patient with a cardiac thrombus and a history of myocardial infarction and (3) to avoid a synthetic graft in a patient with antiphospholipid syndrome. Vena cava stenting and portorenal shunt make a useful combination which should be included in the armamentarium of the hepatobiliary surgeon.  相似文献   
63.
OBJECTIVES: Aim of this study was to evaluate implication of pregnancy induced hypertension on maternal plasma lipid, lipoprotein, apolipoprotein concentrations and lipid peroxidation products by a comparison of normal pregnancy vs. preeclampsia. DESIGN AND METHODS: Thirty-four women with preeclampsia and 32 healthy pregnant women (controls) in the third trimester were recruited for this study. RESULTS: In the preeclamptic group plasma total triglyceride, low density lipoprotein cholesterol (LDL-C), malondialdehyde (MDA) and apolipoprotein B (apo-B) were significantly increased, while plasma high density lipoprotein cholesterol (HDL-C) was significantly decreased compared to that of control group. There was no significant difference in total cholesterol and apolipoprotein A1 (apo-A1) concentrations. CONCLUSION: Our findings suggest that preeclampsia share some metabolic characteristics with coronary artery disease such as dislipidemia and increased lipid peroxidation. However lipoprotein concentrations may be better biochemical markers of dislipidemia in the preeclamptic state than the corresponding apolipoproteins.  相似文献   
64.
Hyper-IgM syndrome (HIGM) is a heterogeneous condition characterized by impaired Ig class-switch recombination (CSR). The molecular defects that have so far been associated with this syndrome - which affect the CD40 ligand in HIGM type 1 (HIGM1), CD40 in HIGM3, and activation-induced cytidine deaminase (AID) in HIGM2 - do not account for all cases. We investigated the clinical and immunological characteristics of 15 patients with an unidentified form of HIGM. Although the clinical manifestations were similar to those observed in HIGM2, these patients exhibited a slightly milder HIGM syndrome with residual IgG production. We found that B cell CSR was intrinsically impaired. However, the generation of somatic hypermutations was observed in the variable region of the Ig heavy chain gene, as in control B lymphocytes. In vitro studies showed that the molecular defect responsible for this new HIGM entity (HIGM4) occurs downstream of the AID activity, as the AID gene was induced normally and AID-induced DNA double-strand breaks in the switch micro region of the Ig heavy chain locus were detected during CSR as normal. Thus, HIGM4 is probably the consequence of a selective defect either in a CSR-specific factor of the DNA repair machinery or in survival signals delivered to switched B cells.  相似文献   
65.
OBJECTIVES: The relationship between plasma total Homocysteine (tHcy) and oxidative stress and plasma levels of lipids, insulin and copper levels were investigated in obese and nonobese hypertensives. DESIGN AND METHODS: Plasma tHcy levels were determined by an enzyme immunoassay method. Plasma lipid peroxidation levels were measured as thiobarbituric acid reactive substances (TBARS) by spectrophotometric methods. Plasma levels of copper and insulin were measured by atomic absorption spectrophotometer and electrochemiluminescence method, respectively. RESULTS: Plasma tHcy, copper and insulin levels did not differ in nonobese hypertensives compared to nonobese normotensives. Plasma TBARS levels were significantly increased in nonobese hypertensives when compared to nonobese normotensives (p < 0.001). Plasma tHcy, TBARS, copper and fasting insulin levels were significantly higher in obese normotensives and hypertensives than in nonobese normotensives and hypertensives, respectively (for each comparison; p < 0.001). There was a significant difference in plasma tHcy, TBARS and copper levels between obese subjects with or without hypertension (for each comparison p < 0.01). The univariate analyses demonstrated a significant positive correlation between tHcy and TBARS (coefficient +/- SE, 0.411 +/- 0.115, p < 0.01) and copper (coefficient +/- SE, 0.425 +/- 0.135, p < 0.01) in obese subjects. In a multivariate regression analysis in obese subjects tHcy was positively correlated with TBARS (coefficient +/- SE, 0.480 +/- 0.155, p < 0.01) and copper (coefficient +/- SE, 0.486 +/- 0.140, p < 0.01). CONCLUSIONS: We hypothesize that in the presence of other traditional risk factors, Hcy may have a permissive role in the endothelium damage even within the normal range and this role may be related to free radical generating systems. Therefore, modest elevation of plasma Hcy may causally be involved in the pathogenesis of atherosclerosis and/or cardiovascular disease.  相似文献   
66.
67.
Two Turkish populations, one with an urban background and the other rural, were compared in regard to their colonic function. Rural subjects consume a diet with higher fiber than urban people in Turkey. The rural group had a greater daily fecal output, faster intestinal transit, and lower intraluminal pressure, with a greater output of calcium in the feces than those living in an urban area in Turkey. The effects are similar to those described when fiber is added to the diet. Urban dwellers in Turkey who lack these effects are said to have a rising incidence of fiber-related diseases of the colon, such as diverticular disease.  相似文献   
68.
The SOCS-1 gene methylation in chronic myeloid leukemia patients   总被引:1,自引:0,他引:1  
SOCS-1, an important protein in the JAK/STAT pathway, has a role in the down stream of BCR-ABL protein kinase. We investigated 56 CML patients and 16 controls for the methylation status of SOCS-1 gene promoter and Exon 2 regions. Exon 2 was found to be methylated in 58.9% of the patients and 93.8% of the controls [P = 0.020, OR = 0.121(0.015-0.957)%95CI]. The promoter region was found unmethylated in all patient samples and controls. Although previous studies revealed a relation between SOCS1 gene Exon-2 hypermethylation and CML development or progression, the results of this study showed no such correlation. On the contrary, our results might be indicating hypomethylation in CML patients, this hypothesis need to be studied in larger study population.  相似文献   
69.
70.
Malignant transformation in testicular teratomas has been reported very rarely in the literature. Although testicular teratomas in childhood are regarded as benign neoplasms, these tumors, if left untreated until advanced ages, may present the risk of malignant transformation. We report a case of differentiated adenocarcinoma originating from colonic glands in primary testicular teratoma.  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