全文获取类型
收费全文 | 5135篇 |
免费 | 393篇 |
国内免费 | 28篇 |
学科分类
医药卫生 | 5556篇 |
出版年
2023年 | 36篇 |
2022年 | 40篇 |
2021年 | 126篇 |
2020年 | 109篇 |
2019年 | 154篇 |
2018年 | 178篇 |
2017年 | 108篇 |
2016年 | 144篇 |
2015年 | 144篇 |
2014年 | 178篇 |
2013年 | 245篇 |
2012年 | 393篇 |
2011年 | 421篇 |
2010年 | 223篇 |
2009年 | 208篇 |
2008年 | 310篇 |
2007年 | 348篇 |
2006年 | 306篇 |
2005年 | 334篇 |
2004年 | 277篇 |
2003年 | 252篇 |
2002年 | 250篇 |
2001年 | 81篇 |
2000年 | 68篇 |
1999年 | 65篇 |
1998年 | 59篇 |
1997年 | 26篇 |
1996年 | 29篇 |
1995年 | 21篇 |
1994年 | 21篇 |
1993年 | 21篇 |
1992年 | 44篇 |
1991年 | 29篇 |
1990年 | 25篇 |
1989年 | 26篇 |
1988年 | 24篇 |
1987年 | 24篇 |
1986年 | 14篇 |
1985年 | 17篇 |
1984年 | 9篇 |
1983年 | 13篇 |
1981年 | 11篇 |
1980年 | 9篇 |
1979年 | 13篇 |
1977年 | 7篇 |
1974年 | 7篇 |
1973年 | 7篇 |
1971年 | 11篇 |
1970年 | 8篇 |
1969年 | 12篇 |
排序方式: 共有5556条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
A randomized trial using telehealth technology to link caregivers with dementia care experts for in‐home caregiving support: FamTechCare protocol 下载免费PDF全文
105.
Kristine Pezdirc Melinda J. Hutchesson Ross Whitehead Gozde Ozakinci David Perrett Clare E. Collins 《Nutrients》2015,7(7):5800-5815
Fruit and vegetables contain carotenoid pigments, which accumulate in human skin, contributing to its yellowness. This effect has a beneficial impact on appearance. The aim was to evaluate associations between diet (fruit, vegetable and dietary carotenoid intakes) and skin color in young women. Ninety-one Caucasian women (Median and Interquartile Range (IQR) age 22.1 (18.1–29.1) years, BMI 22.9 (18.5–31.9) kg/m2) were recruited from the Hunter region (Australia). Fruit, vegetable and dietary carotenoid intakes were estimated by a validated food frequency questionnaire. Skin color was measured at nine body locations (sun exposed and unexposed sites) using spectrophotometry. Multiple linear regression was used to assess the relationship between fruit and vegetable intakes and skin yellowness adjusting for known confounders. Higher combined fruit and vegetable intakes (β = 0.8, p = 0.017) were associated with higher overall skin yellowness values. Higher fruit combined fruit and vegetable intakes (β = 1.0, p = 0.004) were associated with increased unexposed skin yellowness. Combined fruit and vegetables plus dietary carotenoid intakes contribute to skin yellowness in young Caucasian women. Evaluation of interventions using improvements in appearance as an incentive for increasing fruit and vegetable consumption in young women is warranted. 相似文献
106.
Kristine L P Garcia Kathy Coen Sharon Miksys Anh Dzung Lê Rachel F Tyndale 《Neuropsychopharmacology》2015,40(8):1910-1918
The CYP2B enzyme is expressed in human and rat brain, and metabolizes many CNS-acting drugs. The gene that encodes human CYP2B6 is highly polymorphic, where the variation in brain enzyme levels could result in altered brain drug levels. CYP2B can metabolize nicotine, the main psychoactive ingredient in cigarettes; if altered brain CYP2B activity can influence nicotine brain levels, it could influence nicotine-mediated behaviors. To investigate this, a mechanism-based inhibitor selective for CYP2B, C8-xanthate (20 μg), was administered intracerebroventricularly (ICV) into the brain of rats, and 22 h later, nicotine levels were measured by in vivo microdialysis following nicotine (150 μg/kg intravenous). Brain nicotine levels from 15 to 30 min and the AUC0–45min were both twofold higher (p<0.05) with C8-xanthate vs vehicle pretreatment; there was no difference in peripheral nicotine levels. Rats were then given ICV pretreatment with C8-xanthate/ASCF and underwent intravenous nicotine self-administration with 3.75–30 μg/kg per infusion dose. C8-xanthate pretreatment increased responding in progressive ratio (15 μg/kg per infusion dose, p<0.05). In a separate cohort, C8-xanthate increased the percentage of rats that acquired self-administration (7.5 μg/kg per infusion dose, p<0.05) from 40% after vehicle pretreatment to 100%, with no difference in peripheral nicotine levels measured at the end of behavior. In a third cohort, C8-xanthate increased the number of sessions required to meet extinction criteria (p<0.05). Together these data demonstrate that the brain CYP2B activity can influence nicotine brain levels and subsequent behaviors independent of hepatic metabolism. This suggests that human smokers with variable CYP2B brain levels could have different nicotine levels and reinforcement, which might have a role in smoking behaviors and dependence. 相似文献
107.
What is the most cost-effective treatment for patients with low back pain? A systematic review 总被引:1,自引:0,他引:1
van der Roer N Goossens ME Evers SM van Tulder MW 《Best Practice & Research: Clinical Rheumatology》2005,19(4):671-684
Economic evaluations of the various interventions available for low back pain will help clinicians and policymakers to identify the most beneficial treatment. This chapter aims to evaluate the most cost-effective treatments for patients with non-specific low back pain. Pubmed, Embase and the Cochrane library were used to search for articles published from 1966 to July 2004 using a variety of keywords. References were checked to identify additional studies. The consensus health economic criteria (CHEC) list was used to assess the methodological quality of the studies. We found 17 studies; six of these concluded that the intervention of interest was superior to the control intervention. However, definite conclusions about the most cost-effective intervention could not be drawn because of the heterogeneity of interventions, controls and study populations. More high-quality economic evaluations are needed before such a conclusion can be made. 相似文献
108.
Improvement in spine bone density and reduction in risk of vertebral fractures during treatment with antiresorptive drugs 总被引:26,自引:0,他引:26
Cummings SR Karpf DB Harris F Genant HK Ensrud K LaCroix AZ Black DM 《The American journal of medicine》2002,112(4):281-289
PURPOSE: To estimate how much the improvement in bone mass accounts for the reduction in risk of vertebral fracture that has been observed in randomized trials of antiresorptive treatments for osteoporosis. METHODS: After a systematic search, we conducted a meta-analysis of 12 trials to describe the relation between improvement in spine bone mineral density and reduction in risk of vertebral fracture in postmenopausal women. We also used logistic models to estimate the proportion of the reduction in risk of vertebral fracture observed with alendronate in the Fracture Intervention Trial that was due to improvement in bone mineral density. RESULTS: Across the 12 trials, a 1% improvement in spine bone mineral density was associated with a 0.03 decrease (95% confidence interval [CI]: 0.02 to 0.05) in the relative risk (RR) of vertebral fracture. The reductions in risk were greater than predicted from improvement in bone mineral density; for example, the model estimated that treatments predicted to reduce fracture risk by 20% (RR = 0.80), based on improvement in bone mineral density, actually reduce the risk of fracture by about 45% (RR = 0.55). In the Fracture Intervention Trial, improvement in spine bone mineral density explained 16% (95% CI: 11% to 27%) of the reduction in the risk of vertebral fracture with alendronate. CONCLUSION: Improvement in spine bone mineral density during treatment with antiresorptive drugs accounts for a predictable but small part of the observed reduction in the risk of vertebral fracture. 相似文献
109.
Colonic Surgery With Accelerated Rehabilitation or Conventional Care 总被引:18,自引:4,他引:18
BACKGROUND For patients undergoing colonic surgery, the postoperative hospital stay is usually 6 to 10 days, and the morbidity rate is 15 to 20 percent. Fast-track rehabilitation programs have reduced the hospital stay to 2 to 3 days. The aim of this study was to evaluate the postoperative outcome after colonic resection with conventional care compared with fast-track multimodal rehabilitation.METHODS One hundred thirty consecutive patients receiving conventional care (group 1) in one hospital were compared with 130 consecutive patients receiving multimodal, fast-track rehabilitation (group 2) in another hospital. Outcomes were time to first defecation after surgery, postoperative hospital stay, and morbidity during the first postoperative month.RESULTS Median age was 74 years (group 1) and 72 years (group 2). American Society of Anesthesiologists (ASA) score was significantly higher in group 2 (P < 0.05). Defecation occurred on day 4.5 in group 1 and day 2 in group 2 (P < 0.05). Median hospital stay was 8 days in group 1 and 2 days in group 2 (P < 0.05). The use of a nasogastric tube was longer in group 1 (P < 0.05). The overall complication rate (35 patients) was lower in group 2 (P < 0.05), especially cardiopulmonary complications (5 patients; P < 0.01). Readmission was necessary in 12 percent of cases for group 1 and 20 percent in group 2 (P > 0.05).CONCLUSIONS Time to first defecation, hospital stay, and morbidity may be reduced after colonic resection with fast-track multimodal rehabilitation.Reprints are not available. 相似文献