全文获取类型
收费全文 | 953篇 |
免费 | 97篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 49篇 |
妇产科学 | 14篇 |
基础医学 | 137篇 |
口腔科学 | 29篇 |
临床医学 | 87篇 |
内科学 | 200篇 |
皮肤病学 | 45篇 |
神经病学 | 121篇 |
特种医学 | 38篇 |
外科学 | 88篇 |
综合类 | 11篇 |
一般理论 | 1篇 |
预防医学 | 79篇 |
眼科学 | 32篇 |
药学 | 64篇 |
中国医学 | 3篇 |
肿瘤学 | 52篇 |
出版年
2024年 | 2篇 |
2023年 | 22篇 |
2022年 | 38篇 |
2021年 | 75篇 |
2020年 | 27篇 |
2019年 | 37篇 |
2018年 | 54篇 |
2017年 | 34篇 |
2016年 | 40篇 |
2015年 | 29篇 |
2014年 | 38篇 |
2013年 | 54篇 |
2012年 | 87篇 |
2011年 | 71篇 |
2010年 | 32篇 |
2009年 | 25篇 |
2008年 | 33篇 |
2007年 | 38篇 |
2006年 | 39篇 |
2005年 | 28篇 |
2004年 | 23篇 |
2003年 | 39篇 |
2002年 | 8篇 |
2001年 | 21篇 |
2000年 | 7篇 |
1999年 | 15篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 10篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 11篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 10篇 |
1985年 | 5篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 10篇 |
1979年 | 3篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1961年 | 1篇 |
1941年 | 1篇 |
排序方式: 共有1056条查询结果,搜索用时 15 毫秒
71.
Paul F White Shivani Rawal John Nguyen Alison Watkins 《Journal of PeriAnesthesia Nursing》2003,18(4):247-253
This retrospective evaluation assessed the impact of discharging outpatients home directly from the PACU as an alternative to "PACU bypassing." A total of 1,380 outpatients who had undergone minor ambulatory procedures were evaluated. Nine hundred fifty-two outpatients were admitted to a designated PACU fast-tracking area to facilitate an earlier discharge. Of the outpatients admitted to the PACU fast-track area, 88% were discharged home within 60 minutes (mean time [+/- SD] of 58 +/- 8 minutes]. The remaining 12% were discharged home from the PACU in an average of 88 (+/- 12) minutes. The recovery times for the 428 outpatients who were initially considered for the PACU fact-tracking program but were admitted to the regular PACU and recovered according to the conventional (two-step) pathway were 38 +/- 25 minutes in the PACU, followed by 61 +/- 32 minutes in the day surgery step-down unit. We conclude that this pilot program demonstrates the feasibility of discharging patients home from the PACU. Only 12% of the outpatients who were admitted to the PACU fast-track area failed to be discharged within 60 minutes. The overall times to discharge from the PACU fast-track area compared favorably to discharge times for outpatients bypassing the PACU. This program provides nurses with an alternative recovery pathway for fast-tracking patients after ambulatory surgery. 相似文献
72.
73.
Verma S Sinha R Kumar P Amin F Jain J Tanwar S 《Central Nervous System Agents in Medicinal Chemistry》2012,12(1):55-59
Convolvulus pluricaulis Choisy is a perennial wild herb commonly found on sandy & rocky areas under xerophytic conditions in northern India. It is a reputed drug of ayurveda and reported to posses antioxidant, brain tonic, nervine tonic, laxative and has been used in anxiety, neurosis, epilepsy, insomnia, burning sensation, oedema and urinary disorders. In the present study, methanolic extract of whole plant of Convolvulus pluricaulis Choisy was evaluated for antioxidant activity by using 1, 1-diphenyl-2-picryl- hydrazyl (DPPH) free radical scavenging model and anticonvulsant activity by using maximal electroshock seizure model. In antioxidant activity, ascorbic acid was used as standard agent while results of anticonvulsant studies were compared with phenytoin. Results of antioxidant activity have demonstrated significant free radical scavenging effect for methanolic extract of Convolvulus pluricaulis Choisy. IC50 value of methanolic extract was observed as 41.00μg/ml as compared to 2.03μg/ml of ascorbic acid. Methanolic extract of C. pluricaulis was evaluated for anticonvulsant activity at 250, 500 and 1000mg/kg. Experimental results have shown that at the dose of 500 and 1000mg/kg, C. pluricaulis didn't abolish the hind limb extension, but reduced the mean recovery time from convulsion. 相似文献
74.
75.
Shivani Sahni Marian T Hannan Jeffrey Blumberg L Adrienne Cupples Douglas P Kiel Katherine L Tucker 《Journal of bone and mineral research》2009,24(6):1086-1094
In vitro and in vivo studies suggest that carotenoids may inhibit bone resorption, yet no previous study has examined individual carotenoid intake (other than β‐carotene) and the risk of fracture. We evaluated associations of total and individual carotenoid intake (α‐carotene, β‐carotene, β‐cryptoxanthin, lycopene, lutein + zeaxanthin) with incident hip fracture and nonvertebral osteoporotic fracture. Three hundred seventy men and 576 women (mean age, 75 ± 5 yr) from the Framingham Osteoporosis Study completed a food frequency questionnaire (FFQ) in 1988–1989 and were followed for hip fracture until 2005 and nonvertebral fracture until 2003. Tertiles of carotenoid intake were created from estimates obtained using the Willett FFQ adjusting for total energy (residual method). HRs were estimated using Cox‐proportional hazards regression, adjusting for sex, age, body mass index, height, total energy, calcium and vitamin D intake, physical activity, alcohol, smoking, multivitamin use, and current estrogen use. A total of 100 hip fractures occurred over 17 yr of follow‐up. Subjects in the highest tertile of total carotenoid intake had lower risk of hip fracture (p = 0.02). Subjects with higher lycopene intake had lower risk of hip fracture (p = 0.01) and nonvertebral fracture (p = 0.02). A weak protective trend was observed for total β‐carotene for hip fracture alone, but associations did not reach statistical significance (p = 0.10). No significant associations were observed with α‐carotene, β‐cryptoxanthin, or lutein + zeaxanthin. These results suggest a protective role of several carotenoids for bone health in older adults. 相似文献
76.
77.
Implication of BRCA2 -26G>A 5' untranslated region polymorphism in susceptibility to sporadic breast cancer and its modulation by p53 codon 72 Arg>Pro polymorphism 下载免费PDF全文
Gochhait S Bukhari SI Bairwa N Vadhera S Darvishi K Raish M Gupta P Husain SA Bamezai RN 《Breast cancer research : BCR》2007,9(5):R71
Introduction
The absence of mutation or promoter hypermethylation in the BRCA2 gene in the majority of breast cancer cases has indicated alternative ways of its involvement, deregulated expression being one possibility. We show how a polymorphism in the 5' untranslated region (UTR) of BRCA2 can serve as one such factor. Based on the hypothesis that variants of genes involved in the same pathway can influence the risk provided for breast cancer, the status of p53 codon 72 polymorphism was also investigated and a possible interaction between the polymorphisms was examined. 相似文献78.
79.
Semchuk KM Rosenberg AM McDuffie HH Cessna AJ Pahwa P Irvine DG 《Journal of toxicology and environmental health. Part A》2007,70(7):638-657
Previous research suggests that farmers may have an increased risk of developing autoimmunity and that exposure to certain pesticides may alter immune function. Little is known, however, about the immunologic effects of farming and pesticide exposures. As part of the Prairie Ecosystem Study, associations between detection of antinuclear antibodies (ANA), an autoimmunity indicator, and exposure to the herbicide bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) were investigated in a cross-sectional study of 208 residents (94 women, 114 men) of a cereal-producing region in Saskatchewan, Canada, during spring herbicide application, 1996. The ANA were assayed in serum by indirect immunofluorescence on HEp-2 cells. Bromoxynil was measured in plasma by gas chromatography/mass spectrometry analysis. Associations were explored between ANA detection and detection of bromoxynil in plasma, self-reported use of bromoxynil and other pesticides, farming exposures, gender, age, body mass index (BMI), and residency. The mean age (SD) of the participants was 50.8 (13.6) yr [women: 49.7 (13.5) yr, men: 51.6 (13.6) yr]. ANA prevalence was 37.5% (women: 39.4%, men: 36%,) at 1:40 serum dilution, 17.3% (women: 20.2%, men: 14.9%) at 1:80, and 10.1% (women: 13.8%, men: 7%) at 1:160. In the multiple-variable Generalized Estimating Equation (GEE) logistic regression analyses, female gender was a positive predictor of ANA detection and gender differences were observed in the relative importance of other study factors. None of the variables examined in the multiple-variable GEE analysis were statistically significant predictors of ANA detection for women. For many of these variables, however, the point estimates for women are similar to those seen in men. For men, with adjustment for age, ANA presence was inversely associated with detection of concentrations of bromoxynil in winter or spring samples and recent occupational use of 2,4-dichlorophenoxyacetic acid, and the positive ANA predictors included having a BMI in the obese (BMI > 30.04 kg/m2) category, recent occupational use of trifluralin or fungicides, and current exposure to oilseed, poultry, or dairy production. The inverse association between ANA detection and bromoxynil exposure observed in farmers in this study is consistent with earlier empirical observations that certain pesticides may suppress immune function. Further research is needed to examine whether these findings are confirmed in other populations and to elucidate the biological mechanisms involved. 相似文献
80.