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   7997篇
  免费   428篇
  国内免费   45篇
耳鼻咽喉   89篇
儿科学   184篇
妇产科学   135篇
基础医学   1011篇
口腔科学   187篇
临床医学   673篇
内科学   2041篇
皮肤病学   149篇
神经病学   685篇
特种医学   230篇
外科学   1320篇
综合类   57篇
一般理论   6篇
预防医学   503篇
眼科学   231篇
药学   432篇
中国医学   50篇
肿瘤学   487篇
  2024年   8篇
  2023年   83篇
  2022年   230篇
  2021年   401篇
  2020年   200篇
  2019年   288篇
  2018年   352篇
  2017年   221篇
  2016年   214篇
  2015年   228篇
  2014年   383篇
  2013年   428篇
  2012年   712篇
  2011年   679篇
  2010年   387篇
  2009年   322篇
  2008年   510篇
  2007年   508篇
  2006年   452篇
  2005年   434篇
  2004年   362篇
  2003年   354篇
  2002年   300篇
  2001年   37篇
  2000年   25篇
  1999年   38篇
  1998年   46篇
  1997年   33篇
  1996年   25篇
  1995年   21篇
  1994年   11篇
  1993年   17篇
  1992年   14篇
  1991年   14篇
  1990年   9篇
  1989年   6篇
  1988年   12篇
  1987年   8篇
  1986年   6篇
  1985年   8篇
  1984年   6篇
  1983年   7篇
  1982年   5篇
  1981年   12篇
  1980年   7篇
  1979年   9篇
  1976年   7篇
  1975年   5篇
  1974年   4篇
  1972年   4篇
排序方式: 共有8470条查询结果,搜索用时 0 毫秒
91.
BackgroundThere is uneven association between obesity, traditional risk factors, and cardiovascular events. We aimed to analyze the relation between cardiovascular risk factors, including obesity, with the severity of atherosclerosis in different arterial territories.MethodsArteries from five territories (circle of Willis, carotids, coronaries, aorta, and renal) were taken from 185 persons, newborn to 90 years undergoing autopsy in the Forensic Medical Service in Mexico City, to determine atherosclerotic lesions by histopathological study. Lesions were classified according to the American Heart Association grading system as early (types I–III) and advanced (types IV–VI). The degree of atherosclerosis was correlated with arterial territories and risk factors.ResultsFrequencies of advanced lesions according to arterial territories were as follows: circle of Willis, 28%; right carotid, 36%; left carotid, 25%; right coronary, 71%; left coronary, 85%; right renal, 26%; left renal, 29%; and aorta, 52%; P=.0001, for all analyses. There was a higher risk for advanced lesions with increasing body mass index (BMI) (P=.004). However, after adjusting for age, gender, smoking status, hypertension, and diabetes mellitus, BMI was not independently associated with advanced lesions.ConclusionsCoronary arteries are significantly more affected than other arterial territories regardless of risk factors, showing the effect of local and systemic factors in the severity of atherosclerosis. We did not find an independent association between advanced atherosclerotic lesions and obesity.  相似文献   
92.
93.
Clinical Oral Investigations - To evaluate and compare irrigant distribution throughout the root canal system of mesial roots of mandibular molars after application of distinct adjunctive irrigant...  相似文献   
94.
Plerixafor (PLX) appears to effectively enhance hematopoietic stem-cell mobilization prior to autologous hematopoietic stem cell transplantation (auto-HCT). However, the quality of engraftment following auto-HCT has been little explored. Here, engraftment following auto-HCT was assessed in patients mobilized with PLX through a retrospective, multicenter study of 285 consecutive patients. Information on early and 100-day post-transplant engraftment was gathered from the 245 patients that underwent auto-HCT. The median number of PLX days to reach the stem cell collection goal (≥2 × 106 CD34+ cells/kg) was 1 (range 1–4) and the median PLX administration time before apheresis was 11 h (range 1–18). The median number of apheresis sessions to achieve the collection goal was 2 (range 1–5) and the mean number of CD34+ cells collected was 2.95 × 106/kg (range 0–30.5). PLX administration was safe, with only 2 mild and transient gastrointestinal adverse events reported. The median time to achieve an absolute neutrophil count (ANC) >500/μL was 11 days (range 3–31) and the median time to platelet recovery >20 × 103/μL was 13 days (range 5–69). At 100 days after auto-HCT, the platelet count was 137 × 109/L (range 7–340), the ANC was 2.3 × 109/L (range 0.1–13.0), and the hemoglobin concentration was 123 g/L (range 79–165). PLX use allowed auto-HCT to be performed in a high percentage of poorly mobilized patients, resulting in optimal medium-term engraftment in the majority of patients in whom mobilization failed, in this case mainly due to suboptimal peripheral blood CD34+ cell concentration on day +4 or low CD34+ cell yield on apheresis.  相似文献   
95.
96.
Dual‐energy x‐ray absorptiometry (DXA) is the gold standard method for measuring periprosthetic bone remodeling, but relies on a region of interest (ROI) analysis approach. While this addresses issues of anatomic variability, it is insensitive to bone remodeling events at the sub‐ROI level. We have validated a high‐spatial resolution tool, termed DXA‐region free analysis (DXA‐RFA) that uses advanced image processing approaches to allow quantitation of bone mineral density (BMD) at the individual pixel (data‐point) level. Here we compared the resolution of bone remodeling measurements made around a stemless femoral prosthesis in 18 subjects over 24 months using ROI‐based analysis versus that made using DXA‐RFA. Using the ROI approach the regional pattern of BMD change varied by region, with greatest loss in ROI5 (20%, p < 0.001), and largest gain in ROI4 (6%, p < 0.05). Analysis using DXA‐RFA showed a focal zone of increased BMD localized to the prosthesis–bone interface (30–40%, p < 0.001) that was not resolved using conventional DXA analysis. The 20% bone loss observed in ROI5 with conventional DXA was resolved to a focal area adjacent to the cut surface of the infero‐medial femoral neck (up to 40%, p < 0.0001). DXA‐RFA enables high resolution analysis of DXA datasets without the limitations incurred using ROI‐based approaches. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:712–716, 2015.  相似文献   
97.
98.

Introduction and objectives

To assess the validity of the original low-risk SCORE function without and with high-density lipoprotein cholesterol and SCORE calibrated to the Spanish population.

Methods

Pooled analysis with individual data from 12 Spanish population-based cohort studies. We included 30 919 individuals aged 40 to 64 years with no history of cardiovascular disease at baseline, who were followed up for 10 years for the causes of death included in the SCORE project. The validity of the risk functions was analyzed with the area under the ROC curve (discrimination) and the Hosmer-Lemeshow test (calibration), respectively.

Results

Follow-up comprised 286 105 persons/y. Ten-year cardiovascular mortality was 0.6%. The ratio between estimated/observed cases ranged from 9.1, 6.5, and 9.1 in men and 3.3, 1.3, and 1.9 in women with original low-risk SCORE risk function without and with high-density lipoprotein cholesterol and calibrated SCORE, respectively; differences were statistically significant with the Hosmer-Lemeshow test between predicted and observed mortality with SCORE (P < .001 in both sexes and with all functions). The area under the ROC curve with the original SCORE was 0.68 in men and 0.69 in women.

Conclusions

All versions of the SCORE functions available in Spain significantly overestimate the cardiovascular mortality observed in the Spanish population. Despite the acceptable discrimination capacity, prediction of the number of fatal cardiovascular events (calibration) was significantly inaccurate.Full English text available from:www.revespcardiol.org/en  相似文献   
99.
Previous studies have shown that fosmidomycin, risedronate, and nerolidol exert antimalarial activity in vitro. We included squalestatin, an inhibitor of the isoprenoid metabolism in Erwinia uredovora, and found that combinations of compounds which act on different targets of the plasmodial isoprenoid pathway possess important supra-additivity effects.  相似文献   
100.
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