全文获取类型
收费全文 | 26611篇 |
免费 | 2244篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 274篇 |
儿科学 | 931篇 |
妇产科学 | 717篇 |
基础医学 | 3163篇 |
口腔科学 | 435篇 |
临床医学 | 4139篇 |
内科学 | 4818篇 |
皮肤病学 | 325篇 |
神经病学 | 1998篇 |
特种医学 | 1033篇 |
外国民族医学 | 3篇 |
外科学 | 3134篇 |
综合类 | 552篇 |
一般理论 | 37篇 |
预防医学 | 3257篇 |
眼科学 | 750篇 |
药学 | 1941篇 |
中国医学 | 22篇 |
肿瘤学 | 1370篇 |
出版年
2023年 | 139篇 |
2022年 | 182篇 |
2021年 | 455篇 |
2020年 | 328篇 |
2019年 | 490篇 |
2018年 | 534篇 |
2017年 | 371篇 |
2016年 | 467篇 |
2015年 | 481篇 |
2014年 | 675篇 |
2013年 | 1062篇 |
2012年 | 1403篇 |
2011年 | 1606篇 |
2010年 | 789篇 |
2009年 | 720篇 |
2008年 | 1410篇 |
2007年 | 1409篇 |
2006年 | 1418篇 |
2005年 | 1383篇 |
2004年 | 1385篇 |
2003年 | 1268篇 |
2002年 | 1186篇 |
2001年 | 622篇 |
2000年 | 634篇 |
1999年 | 586篇 |
1998年 | 310篇 |
1997年 | 276篇 |
1996年 | 257篇 |
1995年 | 244篇 |
1994年 | 208篇 |
1993年 | 195篇 |
1992年 | 440篇 |
1991年 | 432篇 |
1990年 | 412篇 |
1989年 | 418篇 |
1988年 | 367篇 |
1987年 | 343篇 |
1986年 | 342篇 |
1985年 | 332篇 |
1984年 | 284篇 |
1983年 | 242篇 |
1982年 | 180篇 |
1981年 | 140篇 |
1979年 | 195篇 |
1978年 | 171篇 |
1977年 | 142篇 |
1976年 | 130篇 |
1974年 | 162篇 |
1973年 | 144篇 |
1972年 | 129篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
161.
Effect of peri-operative red blood cell transfusion on 30-day and 1-year mortality following coronary artery bypass surgery. 总被引:2,自引:0,他引:2
Manoj Kuduvalli Aung Y Oo Nick Newall Antony D Grayson Mark Jackson Michael J Desmond Brian M Fabri Abbas Rashid 《European journal of cardio-thoracic surgery》2005,27(4):592-598
OBJECTIVE: The purpose of this study was to examine the effect of peri-operative red blood cell (RBC) transfusion on 30-day and 1-year mortality following coronary artery bypass grafting (CABG). METHODS: We retrospectively analysed 3024 consecutive patients who underwent isolated CABG between January 1999 and December 2001. Patient records were linked to the National Strategic Tracing Service, which records all mortality in the UK. Thirty-day and 1-year mortality were derived from Kaplan-Meier curves. Confounding variables were controlled for by constructing a propensity score for the probability of receiving a transfusion from core patient characteristics including the lowest recorded laboratory haemoglobin (LL Hb) from a clinical chemistry database (C statistic 0.81). The propensity score and the comparison variable (transfusion versus no transfusion) were included in a Cox proportional hazards analysis, allowing calculation of adjusted hazard ratios (HR) and Kaplan-Meier survival curves. RESULTS: Nine hundred and forty (31.1%) patients received RBC transfusion during or within 72h of surgery. Predictors of the need for transfusion were LL Hb and lower body mass index, use of cardiopulmonary bypass, female sex, number of grafts, renal dysfunction, increased age, extent of disease, and prior CABG; these factors were all included in the propensity score. After 1-year of follow-up, 122 (4.03%) deaths occurred. The crude HR for 1-year mortality in patients transfused was 3.0 (P<0.001). After adjusting for the propensity score, re-operation for bleeding, peri-operative blood loss and post-operative complications, the adjusted 30-day mortality was 1.9% in transfused patients compared to 1.1% in patients not transfused (P<0.05). The adjusted HR for 1-year mortality in patients transfused was 1.88 (P<0.01). CONCLUSIONS: Peri-operative RBC transfusion after CABG is associated with an increased risk of mortality during a 1-year follow-up period, with a large proportion of deaths occurring within 30-days. 相似文献
162.
Kristina Jackson Behan 《Clinical laboratory science》2005,18(4):221-225
OBJECTIVE: Screening for diabetes is recommended for individuals > or =45 years of age, or earlier if they manifest > or = one specific risk factors. This study examined the sensitivity and positive predictive value (PPV) of risk factor total for identifying individuals with diabetes and prediabetes. DESIGN: Subjects were interviewed to assess the presence of risk factors. Fasting plasma glucose levels were obtained. SETTING: The study occurred at a health fair in Greensburg, PA. PATIENTS: Six hundred sixty-one Caucasians between the ages of 19 and 100. RESULTS: Using the criterion of screening individuals with > or = one risk factors detected 100% of both diabetics and prediabetics. This dropped to 91.2% when screening individuals with > or = two factors. The PPV of the risk factor total was poor (80% of individuals with a total of four factors were not diabetic). The ability of the risk factor total to predict individuals with impaired glucose metabolism (prediabetics + diabetics) was considerably better, and increased almost linearly with the risk factor total. Of the subjects with normal glucose values, the mean glucose increased as the risk factor total increased. CONCLUSION: While the sensitivity of using > one risk factor as an algorithm to screen is 100% for identifying diabetics, the PPV of risk factor analysis for identifying diabetics is poor. The same algorithm works well to identify at-risk individuals, presumably allowing early intervention and education. 相似文献
163.
S Warburton M A Jackson R Norton M Bhabra 《中国处方药》2004,(10):83-84
当病人出现咳血、胸膜痛等症状,一般都会诊断为肺栓塞。现在有一种趋势就是为了不耽误病人的治疗,在诊断阶段还没有彻底的检查就开始治疗。通常早期使用肝素来减少可疑为肺栓塞病人的死亡率和发病率。然而,如道其它一些并不常见的咳血的原因也非常重要。 相似文献
164.
165.
166.
167.
Belinda Garner Andrew M. Chanen Lisa Phillips Dennis Velakoulis Stephen J. Wood Henry J. Jackson Christos Pantelis Patrick D. McGorry 《Psychiatry Research: Neuroimaging》2007,156(3):257-261
This study used magnetic resonance imaging to examine pituitary gland volume (PGV) in teenage patients with a first presentation of borderline personality disorder (BPD). No difference in PGV was observed between healthy controls (n = 20) and the total BPD cohort (n = 20). However, within the BPD cohort, those exposed to childhood trauma (n = 9) tended to have smaller pituitaries (− 18%) than those with no history of childhood trauma (n = 10). These preliminary findings suggest that exposure to childhood trauma, rather than BPD, per se, might be associated with reduced PGV, possibly reflecting hypothalamic–pituitary–adrenal axis dysfunction. 相似文献
168.
Thompson Debra A.; Janecke Andreas R.; Lange Jessica; Feathers Kecia L.; Hubner Christian A.; McHenry Christina L.; Stockton David W.; Rammesmayer Gabriele; Lupski James R.; Antinolo Guillermo; Ayuso Carmen; Baiget Montserrat; Gouras Peter; Heckenlively John R.; den Hollander Anneke; Jacobson Samuel G.; Lewis Richard A.; Sieving Paul A.; Wissinger Bernd; Yzer Suzanne; Zrenner Eberhart; Utermann Gerd; Gal Andreas 《Human molecular genetics》2006,15(9):1559
Human Molecular Genetics 相似文献
169.
170.