全文获取类型
收费全文 | 2171052篇 |
免费 | 153997篇 |
国内免费 | 3202篇 |
专业分类
耳鼻咽喉 | 31327篇 |
儿科学 | 72335篇 |
妇产科学 | 59025篇 |
基础医学 | 307681篇 |
口腔科学 | 59370篇 |
临床医学 | 191140篇 |
内科学 | 423174篇 |
皮肤病学 | 48691篇 |
神经病学 | 167782篇 |
特种医学 | 86528篇 |
外国民族医学 | 859篇 |
外科学 | 331613篇 |
综合类 | 44950篇 |
现状与发展 | 2篇 |
一般理论 | 619篇 |
预防医学 | 158642篇 |
眼科学 | 49084篇 |
药学 | 166734篇 |
9篇 | |
中国医学 | 4684篇 |
肿瘤学 | 124002篇 |
出版年
2018年 | 22422篇 |
2017年 | 17219篇 |
2016年 | 19083篇 |
2015年 | 21465篇 |
2014年 | 29637篇 |
2013年 | 44583篇 |
2012年 | 61088篇 |
2011年 | 64652篇 |
2010年 | 38517篇 |
2009年 | 36338篇 |
2008年 | 61001篇 |
2007年 | 65339篇 |
2006年 | 66190篇 |
2005年 | 63990篇 |
2004年 | 62058篇 |
2003年 | 60002篇 |
2002年 | 58473篇 |
2001年 | 111583篇 |
2000年 | 115568篇 |
1999年 | 97281篇 |
1998年 | 25306篇 |
1997年 | 22657篇 |
1996年 | 23005篇 |
1995年 | 21674篇 |
1994年 | 20188篇 |
1993年 | 18876篇 |
1992年 | 75325篇 |
1991年 | 72936篇 |
1990年 | 71445篇 |
1989年 | 68390篇 |
1988年 | 62469篇 |
1987年 | 61115篇 |
1986年 | 57176篇 |
1985年 | 54445篇 |
1984年 | 40112篇 |
1983年 | 33753篇 |
1982年 | 19032篇 |
1981年 | 17077篇 |
1979年 | 35781篇 |
1978年 | 24451篇 |
1977年 | 21245篇 |
1976年 | 19177篇 |
1975年 | 21259篇 |
1974年 | 24755篇 |
1973年 | 23834篇 |
1972年 | 22358篇 |
1971年 | 20591篇 |
1970年 | 19270篇 |
1969年 | 18053篇 |
1968年 | 16202篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Manuel P Magalh?es 《Revista portuguesa de cardiologia》2003,22(10):1197-1199
32.
Sebastian Bonner Thomas Matte Mitchell Rubin Joanne K Fagan Jennifer Ahern David Evans 《The Journal of asthma》2006,43(1):31-35
Although studies have documented underuse of controller medications and overuse of short-acting inhaled ss(2)-agonist among children with persistent asthma in disadvantaged communities, the persistence of oral ss(2)-agonist use in pediatric practice has not been studied since inhaled short-acting ss(2)-agonists became widespread. We describe medications used to treat asthma among children 3 to 5 years of age at 10 Head Start and other subsidized preschool centers in East and Central Harlem, New York City. We interviewed 149 parents/guardians of children who were identified as having probable asthma based on physician's diagnosis, persistent symptoms, hospitalization, and medication use. We classified 86 of the 149 children (58%) as having current persistent asthma. Only 15 of them (17%) were reported to have used controller medications at least 5 days/week in the last 4 weeks-only 2 of whom used inhaled corticosteroids. By contrast, 53 children (62%) used oral ss(2)-agonist in the last 4 weeks, often (72%) in conjunction with nebulized or inhaled short-acting ss(2)-agonist. Use of oral ss(2)-agonist was associated with more severe symptoms. This study documents the continued widespread use of oral ss(2)-agonist for treatment of children in a low-income community with high prevalence of asthma. 相似文献
33.
34.
35.
36.
R C Pattinson L C Snyman A P Macdonald 《Suid-Afrikaanse tydskrif vir geneeskunde》2006,96(11):1191-1194
AIM: To evaluate whether the introduction of a strict protocol approach based on the systemic evaluation of critically ill pregnant women with complications of abortion affected outcome. SETTING: Indigent South Africans managed in the regional and tertiary hospitals of the Pretoria Academic Complex. METHOD: Since 1997 a standard definition of severe acute maternal morbidity (SAMM) has been used in the Pretoria Academic Complex. All cases of SAMM and maternal deaths were entered on the Maternal Morbidity and Mortality Audit System programme. A comparison of outcome of severely ill women who had complications of abortion was made between 1997-1998 (original protocol) and 2002-2004 (strict protocol). OUTCOME MEASURES: The mortality index and prevalence of organ system failure or dysfunction. RESULTS: In 1997-1998 there were 43 women with SAMM who survived and a further 10 maternal deaths due to complications of abortion, compared with 107 women with SAMM and 7 maternal deaths during 2002-2004. The mortality index declined from 18.9% in 1997-1998 to 6.1% in 2002-2004 (p = 0.02, odds ratio 0.28, 95% confidence limits 0.10 - 0.79). Significantly more women had hypovolaemic shock in 2002-2004 compared with 1997-1998 (54.4% v. 35.8%, p = 0.04), but fewer women had immune system failure including septic shock (18.4% v. 47.2%, p = 0.0002) and metabolic dysfunction (0 v. 5.7%, p = 0.03) and there was a trend to less renal failure (10.5% v. 22.6%, p = 0.06) and cardiac failure (4.4% v. 13.2%, p = 0.08). CONCLUSION: The strict protocol approach based on systemic evaluation in managing critically ill pregnant women with complications of abortion, coupled with an intensive, regular feedback mechanism, has been associated with a reduction in the mortality index. 相似文献
37.
38.
39.
Burkitt’s lymphoma is a high-grade, rapidly growing B-cell neoplasm. It is recognized by its aggressive course, brief median survival, and low rates of long-term survival. The authors discuss the case of a patient who acutely presented with intraabdominal complications from a new onset of Burkitt’s lymphoma. The clinical and pathological features, staging, treatment options, and survival data are reviewed. In addition, the role of surgical intervention is carefully analyzed. 相似文献
40.
La Creis R Kidd K Woodson P R Taylor D Albanes J Virtamo J A Tangrea 《European journal of cancer prevention》2003,12(4):317-320
Glutathione-S-transferase (GST) genes encode a family of detoxification enzymes that offer protection against endogenous and exogenous sources of reactive oxygen species (ROS). Germline variations in GST genes may alter the catalytic efficiency of GST isoenzymes leading to a potential increase in susceptibility to the genotoxic effects of ROS and electrophilic substances. A nested case-control study design was used to examine the association between the polymorphic GST genes and prostate cancer risk among Finnish male smokers of the ATBC Cancer Prevention Study. A case-case analysis was used to determine the association between these genetic polymorphisms and prostate cancer progression. Germline DNA was obtained from 206 prostate cancer cases and 194 controls frequency matched on age, intervention group and study clinic. Cases and controls were genotyped for three GST genes using MALDI-TOF mass spectrometry or multiplex polymerase chain reaction (PCR). Relative to the wild-type genotype, we observed a 36% reduction in prostate cancer risk associated with the GST-M1-null genotype (odds ratio (OR) 0.64, 95% confidence interval (CI) 0.43, 0.95). Unlike GST-M1, GST-T1-null (OR 0.74, 95% CI 0.42, 1.33) and GST-P1*B (OR 1.10, 95% CI 0.72, 1.69) were not strongly associated with prostate cancer risk. We did not observe any significant associations between the selected polymorphic GST genes and tumour grade or stage. In conclusion, we did not observe a direct association between polymorphic GST-T1 or GST-P1 and prostate cancer risk. Our observation of a relatively strong inverse association between the GST-M1-null genotype and prostate cancer risk needs to be confirmed in larger association studies. 相似文献