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   1044篇
  免费   73篇
  国内免费   4篇
耳鼻咽喉   3篇
儿科学   31篇
妇产科学   26篇
基础医学   150篇
口腔科学   10篇
临床医学   79篇
内科学   266篇
皮肤病学   20篇
神经病学   84篇
特种医学   25篇
外科学   70篇
综合类   5篇
预防医学   115篇
眼科学   50篇
药学   116篇
中国医学   17篇
肿瘤学   54篇
  2023年   6篇
  2022年   16篇
  2021年   41篇
  2020年   11篇
  2019年   28篇
  2018年   35篇
  2017年   23篇
  2016年   22篇
  2015年   31篇
  2014年   42篇
  2013年   47篇
  2012年   85篇
  2011年   86篇
  2010年   54篇
  2009年   44篇
  2008年   74篇
  2007年   76篇
  2006年   71篇
  2005年   73篇
  2004年   77篇
  2003年   56篇
  2002年   55篇
  2001年   3篇
  2000年   3篇
  1999年   8篇
  1998年   9篇
  1997年   3篇
  1996年   5篇
  1995年   8篇
  1994年   1篇
  1993年   2篇
  1992年   4篇
  1990年   2篇
  1989年   7篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1984年   3篇
  1980年   1篇
  1977年   2篇
排序方式: 共有1121条查询结果,搜索用时 31 毫秒
41.
International Ophthalmology - The purpose of this prospective, randomized, double-masked, study was to compare the visual performance of patients after bilateral implantation of six different IOLs....  相似文献   
42.
Neuromyelitis optica is a rare neurological autoimmune disorder characterized by a poor prognosis. Immunosuppression can halt disease progression, but some patients are refractory to multiple treatments, experiencing frequent relapses with accumulating disability. Here we report on durable clinical remissions after allogeneic hematopoietic stem cell transplantation in 2 patients suffering from severe forms of the disease. Immunological data evidenced disappearance of the pathogenic antibodies and regeneration of a naive immune system of donor origin. These findings correlated with evident clinical and radiological improvement in both patients, warranting extended clinical trials to investigate this promising therapeutic option. ANN NEUROL 2014;75:447–453  相似文献   
43.
44.
Abdominal Radiology - To compare tumor detectability and conspicuity of standard b = 1000 s/mm2 (b1000) versus ultrahigh b = 2000 s/mm2 (b2000)...  相似文献   
45.
The concept of moderate consumption of ethanol (beverage alcohol) has evolved over time from considering this level of intake to be nonintoxicating and noninjurious, to encompassing levels defined as “statistically” normal in particular populations, and the public health-driven concepts that define moderate drinking as the level corresponding to the lowest overall rate of morbidity or mortality in a population. The various approaches to defining moderate consumption of ethanol provide for a range of intakes that can result in blood ethanol concentrations ranging from 5 to 6 mg/dl, to levels of over 90 mg/dl (i.e., 20 mM). This review summarizes available information regarding the effects of moderate consumption of ethanol on the adult and the developing nervous systems. The metabolism of ethanol in the human is reviewed to allow for proper appreciation of the important variables that interact to influence the level of exposure of the brain to ethanol once ethanol is orally consumed. At the neurochemical level, the moderate consumption of ethanol selectively affects the function of GABA, glutamatergic, serotonergic, dopaminergic, cholinergic, and opioid neuronal systems. Ethanol can affect these systems directly, and/or the interactions between and among these systems become important in the expression of ethanol's actions. The behavioral consequences of ethanol's actions on brain neurochemistry, and the neurochemical effects themselves, are very much dose- and time-related, and the collage of ethanol's actions can change significantly even on the rising and falling phases of the blood ethanol curve. The behavioral effects of moderate ethanol intake can encompass events that the human or other animal can perceive as reinforcing through either positive (e.g., pleasurable, activating) or negative (e.g., anxiolysis, stress reduction) reinforcement mechanisms. Genetic factors and gender play an important role in the metabolism and behavioral actions of ethanol, and doses of ethanol producing pleasurable feelings, activation, and reduction of anxiety in some humans/animals can have aversive, sedative, or no effect in others. Research on the cognitive effects of acute and chronic moderate intake of ethanol is reviewed, and although a number of studies have noted a measurable diminution in neuropsychologic parameters in habitual consumers of moderate amounts of ethanol, others have not found such changes. Recent studies have also noted some positive effects of moderate ethanol consumption on cognitive performance in the aging human. The moderate consumption of ethanol by pregnant women can have significant consequences on the developing nervous system of the fetus. Consumption of ethanol during pregnancy at levels considered to be in the moderate range can generate fetal alcohol effects (behavioral, cognitive anomalies) in the offspring. A number of factors–including gestational period, the periodicity of the mother's drinking, genetic factors, etc.–play important roles in determining the effect of ethanol on the developing central nervous system. A series of recommendations for future research endeavors, at all levels, is included with this review as part of the assessment of the effects of moderate ethanol consumption on the central nervous system  相似文献   
46.
INTRODUCTION AND OBJECTIVES: The acute inflammatory response is an important phenomenon in the pathogenesis of myocardial damage during acute coronary syndrome. Endothelial dysfunction has been found in unstable angina and acute myocardial infarction, although the results are controversial. The purpose of this study was to determine the levels of the soluble endothelial adhesion molecules ICAM-1, VCAM-1 and E-selectin, in patients with unstable angina and acute myocardial infarction, compare the results in both groups, and analyze their relation with the degree of myocardial injury. METHODS: Serum concentrations of ICAM-1, VCAM-1, and E-selectin were measured in 37 control subjects and 43 patients (32 with acute myocardial infarction and 11 with unstable angina). Measurements were made at the time of admission and ten days later using commercial enzyme-linked immunoabsorbent assay (ELISA) kits (R&D Systems, UK). RESULTS: There was a significant increase in E-selectin (p < 0.05) in patients with unstable angina at admission and ten days later. In contrast, patients with acute myocardial infarction showed no significant differences in E-selectin compared with the control group at admission or ten days later. A significant increase in VCAM-1 levels was demonstrated in both groups of patients and ICAM-1 levels in acute myocardial infarction, but the concentrations of VCAM-1 and ICAM-1 in both groups of patients at admission and ten days later did not differ significantly. There was no relation between soluble endothelial adhesion molecule levels and the severity of myocardial damage estimated by cardiac enzymes or electrocardiographic changes. CONCLUSION: This study indicates that serum levels of E-selectin, measured at time of admission and ten days later, could be a marker for unstable angina and might be useful in the differential diagnosis with myocardial infarction.  相似文献   
47.
48.

Introduction

The etiology of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) can influence the efficacy of Public Health preventive strategies. This study aimed to determine the high-risk papillomavirus (HR-HPV) prevalence in CIN2+ cases in unvaccinated women in Galicia (Spain), the expected impact of bivalent vaccination, and the distribution of HPV 16 in squamous lesions.

Material and methods

Ninety-four histologically confirmed cases of CIN2+ (2009–2010) were retrospectively studied: 23 CIN2, 58 CIN3− squamous carcinoma in situ (CIN3-CIS), 5 adenocarcinoma in situ (AIS), and 8 invasive squamous cervical cancer (SCC). Linear Array HPV Genotyping Test (Roche Diagnostics, Mannheim, Germany) was performed on the cervical specimens. Bivalent vaccination impact was calculated, based on regional vaccination coverage data, local HR-HPV prevalence, and reported efficacy (direct and cross-protection) of the vaccine.

Results

HR-HPV prevalence was 96.8%. The most frequent genotypes were HPV 16 (48.8–58.2%) and HPV 31 (9.3%–12.1%), considering single infections or single-multiple infections, respectively (hierarchical attribution). In squamous lesions, HPV 16 prevalence in women younger than 45 years of age increased in severe lesions (CIN3-CIS/SCC, OR 4.2), and was higher than in older women (OR 5.5). The vaccine could reduce the cumulative incidence of CIN2+ by 50.6% (direct protection), or by 62.7% (direct and cross-protection).

Conclusion

HPV vaccination could have a great impact in women younger than 45 years of age due to the high prevalence of HPV 16 in their lesions.  相似文献   
49.
50.
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