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   2354篇
  免费   124篇
  国内免费   13篇
耳鼻咽喉   33篇
儿科学   103篇
妇产科学   83篇
基础医学   225篇
口腔科学   66篇
临床医学   141篇
内科学   493篇
皮肤病学   15篇
神经病学   132篇
特种医学   92篇
外科学   366篇
综合类   29篇
预防医学   108篇
眼科学   200篇
药学   200篇
中国医学   13篇
肿瘤学   192篇
  2023年   31篇
  2022年   58篇
  2021年   82篇
  2020年   53篇
  2019年   62篇
  2018年   67篇
  2017年   57篇
  2016年   65篇
  2015年   97篇
  2014年   137篇
  2013年   140篇
  2012年   230篇
  2011年   202篇
  2010年   111篇
  2009年   103篇
  2008年   125篇
  2007年   135篇
  2006年   101篇
  2005年   105篇
  2004年   111篇
  2003年   90篇
  2002年   76篇
  2001年   15篇
  2000年   15篇
  1999年   20篇
  1998年   9篇
  1997年   11篇
  1996年   11篇
  1995年   7篇
  1994年   8篇
  1993年   6篇
  1992年   9篇
  1991年   16篇
  1990年   6篇
  1989年   9篇
  1987年   6篇
  1986年   8篇
  1985年   7篇
  1979年   6篇
  1978年   4篇
  1977年   5篇
  1976年   8篇
  1975年   4篇
  1974年   7篇
  1971年   4篇
  1970年   4篇
  1969年   7篇
  1968年   6篇
  1967年   5篇
  1966年   4篇
排序方式: 共有2491条查询结果,搜索用时 15 毫秒
71.
Objective. To evaluate the impact of counseling in a simulated medication adherence activity.Design. Students were randomized into 2 groups: patient medication monograph only (PMMO) and patient medication monograph with counseling (PMMC). Both groups received a fictitious medication and monograph. Additionally, the PMMC group received brief counseling. A multiple-choice, paper-based survey instrument was used to evaluate simulated food-drug interactions, adherence, and perceptions regarding the activity’s value and impact on understanding adherence challenges.Assessment. Ninety-two students participated (PMMC, n=45; and PMMO, n=47). Overall, a significantly higher incidence of simulated food-drug interactions occurred in the PMMO group (30%) vs the PMMC group (22%) (p=0.02). Doses taken without simulated food-drug interactions were comparable: 46.2% (PMCC) vs 41.9% (PMMO) (p=0.19). The average number of missed doses were 3.2 (PMMC) vs 2.8 (PMMO) (p=0.55). Approximately 70% of the students found the activity to be valuable and 89% believed it helped them better understand adherence challenges.Conclusion. This activity demonstrated the challenges and important role of counseling in medication adherence.  相似文献   
72.

Aim:

The aim of the study was to evaluate a novel 5 HT3 receptor antagonist (6g) on chronic stress induced changes in behavioural and brain oxidative stress parameter in mice. A complicated relationship exists among stressful stimuli, body''s reaction to stress and the onset of clinical depression. Chronic unpredictable stressors can produce a situation similar to human depression, and such animal models can be used for the preclinical evaluation of antidepressants.

Materials and Methods:

In the present study, a novel and potential 5-HT3 receptor antagonist (4-benzylpiperazin-1-yl)(3-methoxyquinoxalin-2-yl) methanone (6g) with good Log P (3.08) value and pA2(7.5) values, synthesized in our laboratory was investigated to study the effects on chronic unpredictable mild stress (CUMS)-induced behavioural and biochemical alterations in mice. Mice were subjected to different stress paradigms daily for a period of 28 days to induce depressive-like behaviour.

Results:

The results showed that CUMS caused depression-like behaviour in mice, as indicated by the significant (P < 0.05) decrease in sucrose consumption and locomotor activity and increase in immobility the forced swim test. In addition, it was found that lipid peroxidation and nitrite levels were significantly (P < 0.05) increased, whereas glutathione levels, superoxide dismutase and catalase activities decreased in brain tissue of CUMS-treated mice. ‘6g’ (1 and 2 mg/kg, p.o., 21 days) and fluoxetine treatment (20 mg/kg, p.o., 21 days) significantly (P < 0.05) reversed the CUMS-induced behavioural (increased immobility period, reduced sucrose preference and decreased locomotor activity) and biochemical (increased lipid peroxidation; decreased glutathione levels, superoxide dismutase and catalase activities). However fluoxetine treatment (20 mg/kg, p.o., 21 days) significantly decreased the nitrite level in the brain while ‘6g’ (1 and 2 mg/kg, p.o., 21 days) did not show significant (P < 0.05) effect on the nitrite levels in brain.

Conclusion:

Compound ‘6g’ exerted antidepressant-like effects in behavioural despair paradigm in chronically stressed mice by restoring antioxidant mechanisms.KEY WORDS: 5-HT3 receptor antagonist, chronic unpredictable mild stress, depression, oxidative stress  相似文献   
73.
Using positron emission tomography (PET) and an acute dopamine depletion challenge it is possible to estimate endogenous dopamine levels occupying dopamine D2/3 receptors (D2/3R) in humans in vivo. Our group has developed [11C]-(+)-PHNO, the first agonist radiotracer with preferential in vivo affinity for D3R. Thus, the use of [11C]-(+)-PHNO offers the novel possibility of (i) estimating in vivo endogenous dopamine levels at D2/3R using an agonist radiotracer, and (ii) estimating endogenous dopamine levels at D3R in extrastriatal regions such as the substantia nigra, hypothalamus, and ventral pallidum. Ten healthy participants underwent a [11C]-(+)-PHNO PET scan under baseline conditions and another under acute endogenous dopamine depletion achieved via oral administration of alpha-methyl-para-tyrosine (64 mg/kg). [11C]-(+)-PHNO binding was sensitive to acute dopamine depletion, allowing in vivo estimates of endogenous dopamine in D2R-rich regions (caudate and putamen), mixed D2/3R-rich regions (ventral striatum and globus pallidus), and extrastriatal D3R-rich regions (hypothalamus and ventral pallidum). Dopamine depletion decreased self-reported vigor, which was correlated with the reduction in dopamine levels in the globus pallidus. [11C]-(+)-PHNO is a suitable radiotracer for use in estimating endogenous dopamine levels at D2R and D3R in neuropsychiatric populations.  相似文献   
74.
Employing atomistic simulations, we investigated the void collapse mechanisms in single crystal Ni during hydrostatic compression and explored how the atomistic mechanisms of void collapse are influenced by temperature. Our results suggest that the emission and associated mutual interactions of dislocation loops around the void is the primary mechanism of void collapse, irrespective of the temperature. The rate of void collapse is almost insensitive to the temperature, and the process is not thermally activated until a high temperature (∼1200–1500 K) is reached. Our simulations reveal that, at elevated temperatures, dislocation motion is assisted by vacancy diffusion and consequently the void is observed to collapse continuously without showing appreciable strain hardening around it. In contrast, at low and ambient temperatures (1 and 300 K), void collapse is delayed after an initial stage of closure due to significant strain hardening around the void. Furthermore, we observe that the dislocation network produced during void collapse remains the sample even after complete void collapse, as was observed in a recent experiment of nickel-base superalloy after hot isostatic pressing.  相似文献   
75.
Journal of Interventional Cardiac Electrophysiology - Conduction disturbances after transcatheter aortic valve replacement (TAVR) requiring pacemaker (PPM) implantation are a known complication and...  相似文献   
76.
77.
78.
Mass screening for colorectal cancer   总被引:2,自引:0,他引:2  
A voluntary community colorectal cancer screening project to detect occult blood in the stool of asymptomatic individuals was undertaken; 49,353 Hemoccult® II kits were distributed. A total of 23,674 completed kits were returned to a central repository and processed (compliance rate, 48 percent); 851 participants had positive results (3.6 percent). Of the 640 who underwent further medical evaluation, 299 participants (46.7 percent) who had adequate follow-up had no evidence of disease. Diverse disease entities were detected in 341 participants, which was 1.4 percent of those enrolled. Forty-one patients (0.17 percent) showed significant findings that included 29 cancers (0.12 percent) and 12 (0.05 percent) noninvasive malignant polyps. Of the cancers, there were 27 colorectal, one nonHodgkin's lymphoma, and one carcinoma of the vocal cord. In addition, 107 patients (0.45 percent) had benign polyps and 193 patients (0.82 percent) had various diseases of the gastrointestinal tract and other medical conditions. The cost of the program was modest and the results conformed to those found in previous screening surveys. The heightened public awareness of testing for colorectal disease and the detection of early lesions justifies the guaiac test screening program for mass survey.  相似文献   
79.
80.
A patient with nephrocolic fistula secondary to perinephric abscess was treated successfully with nephrectomy, colonic resection, and colocolostomy. Supported in part by the Dorothy Rider Pool Health Care Trust Fund.  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