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   2760篇
  免费   131篇
  国内免费   54篇
耳鼻咽喉   51篇
儿科学   77篇
妇产科学   55篇
基础医学   266篇
口腔科学   106篇
临床医学   252篇
内科学   654篇
皮肤病学   37篇
神经病学   139篇
特种医学   209篇
外科学   421篇
综合类   75篇
一般理论   2篇
预防医学   126篇
眼科学   68篇
药学   218篇
中国医学   11篇
肿瘤学   178篇
  2023年   19篇
  2022年   46篇
  2021年   90篇
  2020年   49篇
  2019年   68篇
  2018年   99篇
  2017年   64篇
  2016年   73篇
  2015年   84篇
  2014年   98篇
  2013年   112篇
  2012年   176篇
  2011年   168篇
  2010年   106篇
  2009年   98篇
  2008年   149篇
  2007年   147篇
  2006年   118篇
  2005年   135篇
  2004年   107篇
  2003年   101篇
  2002年   92篇
  2001年   41篇
  2000年   20篇
  1999年   36篇
  1998年   63篇
  1997年   53篇
  1996年   48篇
  1995年   41篇
  1994年   36篇
  1993年   37篇
  1992年   17篇
  1991年   17篇
  1990年   19篇
  1989年   32篇
  1988年   28篇
  1987年   30篇
  1986年   20篇
  1985年   23篇
  1984年   20篇
  1983年   16篇
  1982年   22篇
  1981年   24篇
  1980年   24篇
  1979年   7篇
  1978年   11篇
  1977年   10篇
  1976年   10篇
  1971年   5篇
  1970年   8篇
排序方式: 共有2945条查询结果,搜索用时 15 毫秒
31.
32.
33.
During the last decade, the rapid economic development in Saudi Arabia resulted in an unbalanced dietary intake pattern within the general population. Consequently, metabolic syndrome was also documented to be highly prevalent in the Middle-East region. We aimed to examine the relationship between selected dietary nutrient intakes and the prevalence of metabolic syndrome in the general adult population of Riyadh, Saudi Arabia. In this cross-sectional study, 185 adult Saudis aged 19 to 60 years (87 males and 98 females (mean age 35.6 ± 13.2 and 37.6 ± 11.7 years, respectively)) were included. The criteria for metabolic syndrome were based on the International Diabetes Foundation (IDF) criteria, and the dietary food intake was assessed by two 24-h dietary recall methods. The odd ratios (ORs) of metabolic syndrome risk across quartiles of selected dietary nutrients were significantly lower for carbohydrates and proteins, as well as for vitamins A, C, E and K, calcium, zinc and magnesium (p < 0.05 for all) in the female group with metabolic syndrome than those without. The pattern of daily dietary intake of selected nutrients among the general population of Saudi Arabia raises concern, and this dietary imbalance could increase the risk of metabolic syndrome, particularly in adult Saudi females.  相似文献   
34.
This study investigated the role of KATP channels in morphine‐induced antinociception and hepatic oxidative stress in acute and inflammatory pain. The KATP channel modulators (KATP channel opener, diazoxide 100 mg/kg, p.o, and KATP channel blocker, glibenclamide, 3 mg/kg i.p.) were administered with morphine (80 mg/kg, i.p.). Antinociception was assessed by the tail‐flick and formalin tests in rats and measured by the area under the curve values and the maximum percent effect for 3 h. The indices of hepatic oxidative stress: glutathione, glutathione peroxidase, and malondialdehyde were then determined in the liver homogenates obtained from the treated animals. In both tests, glibenclamide antagonized morphine‐induced antinociception, whereas diazoxide augmented it in the tail‐flick test only. In the formalin test, glibenclamide alone has a significant hyperalgesic effect, whereas diazoxide decreased the number of flinches. Coadministration of glibenclamide with morphine antagonized the hepatotoxic effect of morphine in both animal models. In the tail‐flick test, glibenclamide administered alone significantly increased malondialdehyde's level. Coadministration of diazoxide with morphine increased glutathione level in the formalin test. Diazoxide administered alone exacerbated the hepatic oxidative stress in both animal models. These findings suggest a role of KATP channel modulators on morphine‐induced antinociception and hepatic oxidative stress. The administration of glibenclamide may prevent morphine‐induced hepatotoxicity. The effectiveness of diazoxide in the management of pain is limited due to its deleterious effect on the liver. However, the interaction of the KATP channel modulators with morphine depends on the differential sensitivity to the pain stimulus.  相似文献   
35.
36.
We have evaluated the fibrinogen/fibrin fragment E antigen assay as a diagnostic test in patients with clinically suspected venous thrombosis by comparing the results of this assay with venography in 272 patients. The result of the fragment E antigen assay was elevated in 79 of 80 patients with positive venograms for recent venous thrombosis (sensitivity 99%) and within the normal range in 161 of 192 patients with normal venograms (specificity 84%). The fragment E assay was also evaluated in 130 medical and surgical controls without evidence of venous thrombosis by leg scanning and the test was found to be relatively nonspecific. However, in the patient group under study, a correct clinical diagnosis of no thrombosis, based on a normal fragment E result, was made in 161 of 162 cases (negative predictive value of 99%). Therefore, a normal test result effectively excludes a diagnosis of venous thrombosis in clinically symptomatic patients. The assay, as currently performed, is technically demanding and takes 24 hr to complete. Therefore, it will have to be simplified before it can be applied to clinical practice.  相似文献   
37.

Background

Nanoparticles (NPs) play an important role in anticancer delivery systems. Surface modified NPs with hydrophilic polymers such as human serum albumin (HSA) have long half-life in the blood circulation system.

Methods

The method of modified nanoprecipitation was utilized for encapsulation of paclitaxel (PTX) in poly (lactic-co-glycolic acid) (PLGA). Para-maleimide benzoic hydrazide was conjugated to PLGA for the surface modifications of PLGA NPs, and then HSA was attached on the surface of prepared NPs by maleimide attachment to thiol groups (cysteines) of albumin. The application of HSA provides for the longer blood circulation of stealth NPs due to their escape from reticuloendothelial system (RES). Then the physicochemical properties of NPs like surface morphology, size, zeta potential, and in-vitro drug release were analyzed.

Results

The particle size of NPs ranged from 170 to 190 nm and increased about 20–30 nm after HSA conjugation. The zeta potential was about -6 mV and it decreased further after HSA conjugation. The HSA conjugation in prepared NPs was proved by Fourier transform infrared (FT-IR) spectroscopy, faster degradation of HSA in Differential scanning calorimetry (DSC) characterization, and other evidences such as the increasing in size and the decreasing in zeta potential. The PTX released in a biphasic mode for all colloidal suspensions. A sustained release profile for approximately 33 days was detected after a burst effect of the loaded drug. The in vitro cytotoxicity evaluation also indicated that the HSA NPs are more cytotoxic than plain NPs.

Conclusions

HSA decoration of PLGA NPs may be a suitable method for longer blood circulation of NPs.  相似文献   
38.
Smartphone technology is nascent compared to other technologies; however, it has shown an unprecedented uptake amongst lay consumers and professionals. This article presents the history, components, and key features of smartphones, as well as their related concepts and how they work, and it also delineates the process of smartphone applications (apps) development and publishing in the app stores. It also describes and discusses smartphone technology utilisation for health consumers, healthcare professionals, and health researchers, as well as the regulations of health-related apps.  相似文献   
39.
This study determined the effects of a high-fat meal on circulating endotoxin and cardiometabolic indices in adult Arab women. The cohort consisted of 92 consenting Saudi women (18 non-diabetic (ND)) control subjects; Age 24.4 ± 7.9 year; body mass index (BMI) 22.2 ± 2.2 Kg/m2), 24 overweight/obese (referred to as overweight-plus (overweight+)) subjects (Age 32.0 ± 7.8 year; BMI 28.5 ± 1.5 Kg/m2) and 50 type 2 diabetes mellitus (T2DM) patients (Age 41.5 ± 6.2 year; BMI 35.2 ± 7.7 Kg/m2). All were given a high-fat meal (standardized meal: 75 g fat, 5 g carbohydrate, 6 g protein) after an overnight fast of 12–14 h. Anthropometrics were obtained and fasting blood glucose, lipids, and endotoxin were serially measured for four consecutive postprandial hours. Endotoxin levels were significantly elevated prior to a high-fat meal in the overweight+ and T2DM than the controls (p < 0.05). Furthermore, the postprandial cardiometabolic changes led to a more detrimental risk profile in T2DM subjects than other groups, with serial changes most notable in glucose, triglycerides, high density lipoprotein-cholesterol (HDL-cholesterol), and insulin levels (p-values < 0.05). The same single meal given to subjects with different metabolic states had varying impacts on cardiometabolic health. Endotoxemia is exacerbated by a high-fat meal in Arab subjects with T2DM, accompanied by a parallel increase in cardiometabolic risk profile, suggesting disparity in disease pathogenesis of those with or without T2DM through the altered cardiometabolic risk profile rather than variance in metabolic endotoxinaemia with a high-fat meal.  相似文献   
40.

Purpose

To evaluate the short-term results of sub-tenon’s injection of bevacizumab in patients with clinically significant macular edema (CSME).

Methods

In this prospective non-comparative interventional case series, sub-tenon’s injection of 2.5 mg/0.1 ml bevacizumab was performed for eyes with CSME. Macular thickness and best corrected visual acuity measurements were performed before and one month after injections.

Results

Nineteen eyes of twelve patients with a mean age of 59.8 ± 5.7 years were evaluated. Thirteen eyes (68.4%) had center-involving macular edema. No significant difference was observed between pre- and post-injection central subfield retinal thickness measurements (P = 0.3). Central subfield thickness measurements improved or remained unchanged in 13 eyes (68.4%). Baseline BCVA of 0.48 ± 0.35 LogMAR improved to 0.36 ± 0.26 LogMAR after injection (P = 0.01). Improvement of >2 lines in BCVA was found in 5 eyes (26.3%), and no eye lost >2 lines of BCVA. No complication associated with sub-tenon’s injection was observed.

Conclusion

Sub-tenon’s injection of bevacizumab resulted in significant short-term visual improvement in eyes with CSME. Retinal thickness changes were not significant.  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