全文获取类型
收费全文 | 4085篇 |
免费 | 355篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 78篇 |
妇产科学 | 100篇 |
基础医学 | 393篇 |
口腔科学 | 76篇 |
临床医学 | 515篇 |
内科学 | 857篇 |
皮肤病学 | 43篇 |
神经病学 | 507篇 |
特种医学 | 119篇 |
外科学 | 542篇 |
综合类 | 125篇 |
一般理论 | 6篇 |
预防医学 | 430篇 |
眼科学 | 42篇 |
药学 | 308篇 |
中国医学 | 1篇 |
肿瘤学 | 269篇 |
出版年
2022年 | 27篇 |
2021年 | 80篇 |
2020年 | 46篇 |
2019年 | 69篇 |
2018年 | 81篇 |
2017年 | 58篇 |
2016年 | 72篇 |
2015年 | 69篇 |
2014年 | 100篇 |
2013年 | 159篇 |
2012年 | 188篇 |
2011年 | 214篇 |
2010年 | 150篇 |
2009年 | 116篇 |
2008年 | 202篇 |
2007年 | 212篇 |
2006年 | 176篇 |
2005年 | 166篇 |
2004年 | 162篇 |
2003年 | 186篇 |
2002年 | 124篇 |
2001年 | 113篇 |
2000年 | 128篇 |
1999年 | 117篇 |
1998年 | 36篇 |
1997年 | 41篇 |
1996年 | 31篇 |
1995年 | 30篇 |
1993年 | 27篇 |
1992年 | 81篇 |
1991年 | 77篇 |
1990年 | 59篇 |
1989年 | 66篇 |
1988年 | 59篇 |
1987年 | 49篇 |
1986年 | 49篇 |
1985年 | 65篇 |
1984年 | 64篇 |
1983年 | 55篇 |
1982年 | 45篇 |
1981年 | 30篇 |
1980年 | 35篇 |
1979年 | 56篇 |
1978年 | 52篇 |
1977年 | 54篇 |
1976年 | 43篇 |
1975年 | 31篇 |
1974年 | 36篇 |
1973年 | 37篇 |
1968年 | 28篇 |
排序方式: 共有4447条查询结果,搜索用时 15 毫秒
81.
Gaugler JE Kane RL Kane RA Newcomer R 《Journal of the American Geriatrics Society》2005,53(12):2098-2105
OBJECTIVES: To determine how unmet needs for activity of daily living tasks influenced nursing home placement, death, or loss to follow-up in dementia. DESIGN: An 18-month longitudinal design, with interviews administered every 6 months. SETTING: Eight catchment areas in the United States. PARTICIPANTS: Five thousand eight hundred thirty-one dementia patients and their caregivers were included at baseline. MEASUREMENTS: Measures of sociodemographic context of care; functional, cognitive, and behavioral status of care recipients; caregiver stress and well-being; and formal and informal resources served as covariates. The independent variables of interest were unweighted unmet care need scores and unmet need scores weighted by importance and severity in a prior sample of older consumers of long-term care. Outcomes included nursing home placement, death, and loss to follow-up. RESULTS: Cox regression models suggested that greater unmet need was predictive of nursing home placement, death, and loss to follow-up. These results were apparent when the unweighted and the weighted scores for unmet need with activity of daily living dependencies were used. CONCLUSION: Unmet need may be useful in identifying dementia care recipients at risk for nursing home placement and death. Further study of unmet need is needed to effectively assess and target intervention protocols during the course of dementia. 相似文献
82.
T cell Ig and mucin 1 (TIM-1) is expressed on in vivo-activated T cells and provides a costimulatory signal for T cell activation 总被引:9,自引:0,他引:9 下载免费PDF全文
83.
Laurent C Bourgeois A Faye MA Mougnutou R Seydi M Gueye M Liégeois F Kane CT Butel C Mbuagbaw J Zekeng L Mboup S Mpoudi-Ngolé E Peeters M Delaporte E 《The Journal of infectious diseases》2002,186(4):486-492
To compare human immunodeficiency virus (HIV) type 1 disease progression in patients infected by the predominant strain circulating recombinant form (CRF) 02_AG in western and west-central Africa and in patients infected by other strains, a prospective multicenter cohort study was conducted in Cameroon and Senegal. Among the 335 patients, a broad HIV-1 group M subtype diversity was observed in the envelope V3-V5 region, but strain CRF02_AG predominated in both Cameroon and Senegal (61.2% and 62.9%, respectively; P<.8). Multivariate analyses showed no difference between patients infected by CRF02 strains and those infected by other strains in terms of survival (adjusted hazards ratio [HR], 1.16; 95% confidence interval [CI], 0.76-1.78; P=.5), clinical disease progression (HR, 0.79; 95% CI, 0.50-1.25; P=.3), or square root CD4 cell decline (regression coefficient, -0.01; 95% CI, -0.82 to 0.81; P=.9). This study suggests that the predominance of HIV-1 CRF02_AG strain in western and west-central Africa should have no major clinical consequences. 相似文献
84.
Tobacco use is associated with accelerated clinical recurrence of Crohn's disease after surgically induced remission 总被引:3,自引:0,他引:3
GOALS: To study the association between tobacco exposure and postoperative clinical recurrence in Crohn's disease patients and quantify the time to clinical relapse following surgical resection. BACKGROUND: It is well accepted that cigarette smoking has a negative impact on postoperative course in Crohn's disease. However, the effect of smoking to hasten clinical recurrence has not been clearly delineated. STUDY: We reviewed medical records of patients undergoing surgical resection for medication-refractory disease within a 5-year period. Patients were followed for a period of 250 weeks. Outcomes were compared between smokers and nonsmokers and stratified by gender. RESULTS: Fifty-nine patients were studied. Sixty-nine percent of smokers versus 23% of nonsmokers had recurrent symptoms (P = 0.02) by the end of the observation period. There was no difference in the mean ages, gender, disease location, use of postoperative medications, or number of postoperative visits (P > 0.09). Smoking was associated with an increased risk of clinical recurrence [odds ratio 2.96 (95% confidence interval, CI 1.5-5.6)]. The time to clinical relapse for smokers was 130 weeks versus 234 weeks in nonsmokers (P < 0.001). CONCLUSION: Smoking is associated with clinical recurrence of Crohn's disease, and the time to clinical recurrence in smokers is shorter. Strategies for smoking cessation are warranted. 相似文献
85.
Comparison of the grading of esophageal varices by transnasal endoluminal ultrasound and esophagogastroduodenoscopy. 总被引:1,自引:0,他引:1
Leonard Kane Michel Kahaleh Vanessa M Shami Steven H Caldwell Carl L Berg Khalouck M Abdrabbo C M Yoshida Kristin O Arseneau Paul Yeaton 《Clinical gastroenterology and hepatology》2005,3(8):806-810
BACKGROUND & AIMS: Esophagogastroduodenoscopy (EGD) is the current standard for evaluating esophageal varices, yet there is no universally accepted system of grading varices endoscopically and several studies have shown interobserver variability of endoscopic grading. High-resolution endoluminal ultrasound 20 MHz (HRES) has been shown to detect varices accurately and can be performed without sedation. Our aim was to compare the detection of esophageal varices by transnasal HRES and EGD. METHODS: We prospectively studied 37 cirrhotic patients being evaluated for esophageal varices. HRES was used to measure the largest esophageal variceal diameter and then EGD was performed. Photographs were taken for both procedures. Three blinded investigators graded the EGD photographs at 2 periods. End points were as follows: (1) the correlation of HRES variceal diameter and EGD grading of varices, and (2) the assessment of interobserver and intraobserver variation in varix grading by EGD. RESULTS: The correlation between the transnasal HRES and EGD was .63, with a 95% confidence interval of .37-.80. The HRES detected early varices that were not seen by EGD. The interobserver correlation for EGD scoring was .87 or greater in all comparisons and the intraobserver correlation was .91 or greater. CONCLUSIONS: In conclusion, there is a significant correlation between transnasal HRES size measurement of esophageal varices and EGD. HRES is much more sensitive in detecting early esophageal varices and may not require sedation, suggesting that it may be more tolerable to patients and is worth further study. 相似文献
86.
Prevalence of malnutrition,obesity and nutritional risk of Australian paediatric inpatients: A national one‐day snapshot 下载免费PDF全文
87.
OBJECTIVE: Chronic beta-adrenoceptor antagonist (beta-blocker) treatment reduces the incidence of reversion to AF in patients, possibly via an adaptive myocardial response. However, the underlying electrophysiological mechanisms are presently unclear. We aimed to investigate electrophysiological changes in human atrial cells associated with chronic treatment with beta-blockers and other cardiovascular-acting drugs. METHODS: Myocytes were isolated enzymatically from the right atrial appendage of 40 consenting patients who were in sinus rhythm. The cellular action potential duration (APD), effective refractory period (ERP), L-type Ca(2+) current (I(CaL)), transient (I(TO)) and sustained (I(KSUS)) outward K(+) currents, and input resistance (R(i)) were recorded using the whole cell patch clamp. Drug treatments and clinical characteristics were compared with electrophysiological measurements using simple and multiple regression analyses. P<0.05 was taken as statistically significant. RESULTS: In atrial cells from patients treated chronically with beta-blockers, the APD(90) and ERP (75 beats/min stimulation) were significantly longer, at 213+/-11 and 233+/-11 ms, respectively (n=15 patients), than in cells from non-beta-blocked patients, at 176+/-12 and 184+/-12 ms (n=11). These cells also displayed a significantly reduced action potential phase 1 velocity (22+/-3 vs. 34+/-3 V/s). Chronic beta-blockade was also associated with a significant reduction in the heart rate (58+/-3 vs. 69+/-5 beats/min) and in the density of I(TO) (8.7+/-1.3 vs. 13.7+/-2.1 pA/pF), an increase in the R(i) (214+/-24 vs. 132+/-14 MOmega), but no significant change in I(CaL) or I(KSUS). The I(TO) blocker 4-aminopyridine largely mimicked the changes in phase 1 and ERP associated with chronic beta-blockade, in cells from non-beta-blocked patients. Chronic treatment of patients with calcium channel blockers or angiotensin converting enzyme inhibitors (n=11-13 patients) was not associated with any significant changes in atrial cell electrophysiology. CONCLUSION: The observed atrial cellular electrophysiological changes associated with chronic beta-blockade are consistent with a long-term adaptive response, a type of 'pharmacological remodelling', and provide mechanistic evidence supportive of the anti-arrhythmic actions of beta-blockade. 相似文献
88.
89.
Au Cherry Gupta Ena Khaing Phue Dibello Joseph Chengsupanimit Todd Mitchell Edith P. West Frances Mae Baram Michael Awsare Bharat K. Kane Gregory C. 《Journal of thrombosis and thrombolysis》2021,51(2):430-436
Journal of Thrombosis and Thrombolysis - To study whether a diagnosis of cancer affects the clinical presentation and outcomes of patients with pulmonary embolism (PE). A retrospective analysis was... 相似文献
90.
Kane Jeremy C. Sharma Anjali Murray Laura K. Chander Geetanjali Kanguya Tukiya Skavenski Stephanie Chitambi Chipo Lasater Molly E. Paul Ravi Cropsey Karen Inoue Sachi Bosomprah Samuel Danielson Carla Kmett Chipungu Jenala Simenda Francis Vinikoor Michael J. 《AIDS and behavior》2022,26(2):523-536
AIDS and Behavior - This randomized controlled trial tested the efficacy of a multi-session, evidence-based, lay counselor-delivered transdiagnostic therapy, the Common Elements Treatment Approach... 相似文献