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   465篇
  免费   28篇
  国内免费   20篇
耳鼻咽喉   4篇
儿科学   17篇
妇产科学   5篇
基础医学   46篇
口腔科学   11篇
临床医学   47篇
内科学   115篇
皮肤病学   13篇
神经病学   17篇
特种医学   42篇
外科学   32篇
综合类   24篇
预防医学   44篇
眼科学   7篇
药学   57篇
中国医学   2篇
肿瘤学   30篇
  2023年   4篇
  2021年   3篇
  2020年   4篇
  2019年   4篇
  2018年   7篇
  2017年   6篇
  2016年   7篇
  2015年   14篇
  2014年   14篇
  2013年   24篇
  2012年   24篇
  2011年   24篇
  2010年   23篇
  2009年   25篇
  2008年   27篇
  2007年   38篇
  2006年   34篇
  2005年   24篇
  2004年   16篇
  2003年   15篇
  2002年   16篇
  2001年   15篇
  2000年   10篇
  1999年   9篇
  1998年   19篇
  1997年   17篇
  1996年   12篇
  1995年   7篇
  1994年   13篇
  1993年   13篇
  1992年   1篇
  1991年   3篇
  1990年   1篇
  1989年   5篇
  1988年   3篇
  1987年   2篇
  1986年   4篇
  1985年   4篇
  1984年   4篇
  1983年   5篇
  1982年   3篇
  1981年   1篇
  1980年   1篇
  1979年   3篇
  1978年   1篇
  1977年   3篇
  1974年   1篇
排序方式: 共有513条查询结果,搜索用时 0 毫秒
91.
92.
OBJECTIVE: The objective of this study was to assess in prospective data whether bacterial vaginosis (BV) is associated with gonococcal/chlamydial cervicitis. STUDY: A total of 1179 women at high risk for sexually transmitted infections was followed for a median of 3 years. Every 6 to 12 months, vaginal swabs were obtained for Gram stain, culture of microflora, and Neisseria gonorrhoeae and Chlamydia trachomatis. A Gram stain score of 7 to 10 based on the Nugent criteria categorized BV. RESULTS: Baseline BV was associated with concurrent gonococcal/chlamydial infection (adjusted odds ratio, 2.83; 95% confidence interval [CI], 1.81-4.42). However, the association between BV and subsequent, incident gonococcal/chlamydial genital infection was not significant (adjusted relative risk [RR], 1.52; 95% CI, 0.74-3.13). Dense growth of pigmented, anaerobic Gram-negative rods (adjusted RR, 1.93; 95% CI, 0.97-3.83) appeared to elevate the risk for newly acquired gonococcal/chlamydial genital infection. CONCLUSIONS: BV was common among a predominantly black group of women with concurrent gonococcal/chlamydial infection but did not elevate the risk for incident infection.  相似文献   
93.
94.
95.
96.
PURPOSE: To determine whether anisometropia increases the risk for the development of accommodative esotropia with hypermetropia. METHODS: Records of all new patients with a refractive error of +2.00 D or more (mean spherical equivalent of both eyes) over a 42-month period were reviewed. Three hundred forty-five patients were thus analyzed to determine the effect of anisometropia (>or=1 D) on the relative risk of developing accommodative esotropia and of developing unsatisfactory control with spectacles once esotropia was present. RESULTS: Anisometropia (>or=1 D) increased the relative risk of developing accommodative esotropia to 1.68 (P < .05). Anisometropia (>or=1 D) increased the relative risk for esotropia to 7.8 (P < .05) in patients with a mean spherical equivalent less than +3.00 D and increased it to 1.49 (P < .05) in patients with a mean spherical equivalent of +3.00 D or more (P = .016). In patients with esotropia and anisometropia (>or=1 D), the relative risk for a deviation that was unsatisfactorily controlled with spectacles was 1.72 (P < .05) compared with patients with esotropia but without anisometropia. Unsatisfactorily controlled esotropia was present in 33% of patients with anisometropia versus 0% of patients without anisometropia, with a mean hypermetropic spherical equivalent of less than +3.00 D (P = .003); however, anisometropia did not significantly increase the relative risk of unsatisfactory control of esotropia with spectacles in patients with a hypermetropic spherical equivalent of +3.00 D or more. Although amblyopia and anisometropia were closely associated, anisometropia increased the relative risk for esotropia to 2.14 (P < .05), even in the absence of amblyopia. CONCLUSIONS: Anisometropia (>or=1 D) is a significant risk factor for the development of accommodative esotropia, especially in patients with lower overall hypermetropia (>+3.00 D). Anisometropia also increases the risk that an accommodative esotropia will not be satisfactorily aligned with spectacles.  相似文献   
97.
The authors describe a case of a 59 year-old Chinese lady with a history of spontaneous left caroticocavernous fistula in 1988 treated by left internal carotid artery clipping and muscle embolisation. She subsequently presented with a subarachnoid haemorrhage in November 1997 secondary to rupture of an unclippable giant right internal carotid artery aneurysm. This was treated satisfactorily with bilateral cervical carotid artery to proximal middle cerebral artery bypass followed by balloon occlusion. Postoperatively, the patient has no neurological deficit and CT angiogram shows good patency of both grafts 6 months after surgery.  相似文献   
98.
BACKGROUND & AIMS: We report a novel approach to study biliary water, bile acid, and HCO(3)(-) transport: the microperfusion of intrahepatic bile duct units (IBDUs) isolated from normal rat liver. METHODS: To study water transport, IBDUs were perfused in vitro with a membrane-impermeant fluorescent volume marker, fluorescein sulfonate; net water movement (J(v)) and osmotic water permeability (P(f)) were then calculated. To study solute transport, IBDUs were perfused with taurocholic acid (TCA) and bile acid uptake was calculated from the concentrations of TCA in the perfused and collected solutions. To study ion transport, IBDUs were perfused with the cell-impermeant pH-sensitive dye BCECF dextran; luminal pH was determined from fluorescence excitation ratios. RESULTS: When inward (secretory) or outward (absorptive) osmotic gradients were established across IBDUs, water movement was observed from bath to lumen (i.e., secretion) and from lumen to bath (i.e., absorption). The perfused IBDUs absorbed TCA in a saturable, sodium-dependent manner; in addition, TCA absorption was blocked in a dose-dependent fashion by S0960, a specific inhibitor of the Na(+)/bile acid cotransporter. Addition of forskolin to HCO(3)(-)-containing (but not HCO(3)(-)-free) bath buffer resulted in lumen alkalinization reflecting HCO(3)(-) transport into the lumen of perfused IBDUs. CONCLUSIONS: The results provide direct functional evidence that intrahepatic bile ducts both secrete and absorb water in response to osmotic gradients, actively absorb bile acid, and transport HCO(3)(-).  相似文献   
99.
100.

Background:

In women, cancer of the breast is one of the most common incident cancer and cause of death from cancer. Anthropometric factors of weight, height, and body mass index (BMI) have been associated with breast cancer risk.

Objectives:

To study the association of overweight and obesity with breast cancer in India.

Materials and Methods:

A hospital-based matched case-control study was conducted. Three hundred and twenty newly diagnosed breast cancer patients and three hundred and twenty normal healthy individuals constituted the study population. The subjects in the control group were matched individually with the patients for their age ±2 years and socioeconomic status. Anthropometric measurements of weight and height were recorded utilizing the standard equipments and methodology. The paired ‘t’ test and univariate logistic regression analysis were carried out.

Results:

It was observed that the patients had a statistically higher mean weight, body mass index, and mid upper arm circumference as compared to the controls. It was observed that the risk of breast cancer increased with increasing levels of BMI. Overweight and obese women had Odd''s redio of 1.06 and 2.27, respectively, as compared to women with normal weight.

Conclusions:

The results of the present study revealed a strong association of overweight and obesity with breast cancer in the Indian population.  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