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   54196篇
  免费   3833篇
  国内免费   558篇
耳鼻咽喉   601篇
儿科学   1522篇
妇产科学   1345篇
基础医学   7643篇
口腔科学   1084篇
临床医学   5093篇
内科学   11589篇
皮肤病学   1258篇
神经病学   4348篇
特种医学   2027篇
外国民族医学   19篇
外科学   7180篇
综合类   1596篇
现状与发展   1篇
一般理论   7篇
预防医学   3894篇
眼科学   924篇
药学   3674篇
  7篇
中国医学   693篇
肿瘤学   4082篇
  2023年   395篇
  2022年   817篇
  2021年   1588篇
  2020年   914篇
  2019年   1228篇
  2018年   1554篇
  2017年   1123篇
  2016年   1178篇
  2015年   1387篇
  2014年   1769篇
  2013年   2343篇
  2012年   3547篇
  2011年   3666篇
  2010年   2149篇
  2009年   1842篇
  2008年   2781篇
  2007年   2893篇
  2006年   2654篇
  2005年   2634篇
  2004年   2416篇
  2003年   2234篇
  2002年   2036篇
  2001年   1671篇
  2000年   1722篇
  1999年   1476篇
  1998年   497篇
  1997年   459篇
  1996年   386篇
  1995年   309篇
  1994年   309篇
  1993年   266篇
  1992年   725篇
  1991年   699篇
  1990年   647篇
  1989年   615篇
  1988年   562篇
  1987年   545篇
  1986年   502篇
  1985年   455篇
  1984年   339篇
  1983年   262篇
  1982年   166篇
  1981年   154篇
  1979年   286篇
  1978年   152篇
  1977年   158篇
  1976年   166篇
  1975年   142篇
  1974年   180篇
  1972年   176篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.

Objective

To systematically review literature on uptake and timeliness of diphtheria-tetanus-pertussis, measles-mumps-rubella, and/or polio-containing vaccines in infants who were born preterm, with a low birth weight, and/or with chronic health conditions that were diagnosed within the first 6?months of life.

Methods

Using a standardized search strategy developed by a medical librarian, records were extracted from MEDLINE, Embase, Database of Abstracts of Reviews of Effects, and CINAHL up to May 8, 2018.

Results

Out of the 1997 records that were screened, we identified 21 studies that met inclusion criteria. Eleven studies assessed vaccine coverage and/or timeliness in preterm infants, 6 in low birth weight infants, and 7 in children with chronic health conditions. Estimates of coverage in these populations were highly variable, ranging from 40% to 100% across the vaccines and population groups.

Conclusions

There is a lack of studies reporting coverage and timeliness of routine immunizations in special populations of children.

Policy implications

Our review suggests a need for improved surveillance of immunization status in special populations of infants, as well as a need for standardization of reporting practices.  相似文献   
3.
4.
It is hypothesized that persons who use drugs (PWUD) in Vietnam who are also HIV-positive may face additional challenges in psychosocial outcomes, and these challenges may extend to their family members. In this study, we examined depressive symptoms, stigma, social support, and caregiver burden of HIV-positive PWUD and their family members, compared to the outcomes of HIV-negative PWUD and their family members. Baseline, 3-month, and 6-month assessment data were gathered from 83 PWUD and 83 family members recruited from four communes in Phú Th? Province, Vietnam. For PWUD, although we observed a general decline in overall stigma over time for both groups, HIV-positive PWUD consistently reported significantly higher overall stigma for all three periods. Depressive symptoms among family members in both groups declined over time; however, family members of HIV-positive PWUD reported higher depressive symptoms across all three periods. In addition, family members of HIV-positive PWUD reported lower levels of tangible support across all three periods. Caregiver burden among family members of HIV-positive PWUD increased significantly over time, whereas the reported burden among family members of HIV-negative PWUD remained relatively unchanged. The findings highlight the need for future interventions for PWUD and family members, with targeted and culturally specific strategies to focus on the importance of addressing additional stigma experienced by PWUD who are HIV-positive. Such challenges may have direct negative impact on their family members' depressive symptoms, tangible support, and caregiver burden.  相似文献   
5.
6.

Objective

To explore from a gender perspective the association with subjective health of the interaction between education and household arrangements within the framework of social determinants of health placed at the micro and mezzo levels.

Methods

The data comes from the Spanish sample of the European Union Statistics on Income and Living Conditions for 2014. Independent logistic regression models for men and women were run to analyze the association with subjective health of the interaction between education and household arrangements. An additive model was run to assess possible advantages over the interaction approach.

Results

The interaction models show a lower or even no significant effect on health of household arrangements usually negatively associated with health among individuals with high education, displaying specific patterns according to sex.

Conclusions

Health profiles of women and men are more precisely drawn if both social determinants of health are combined. Among the women, the important role was confirmed of both social determinants of health in understanding their health inequalities. Among the men, mainly those with low educational achievement, the interaction revealed that the household was a more meaningful social determinant of health. This could enable the definition of more efficient public policies to reduce health and gender inequalities.  相似文献   
7.
8.
9.
背景:Parkin基因(PRKN)突变可导致常染色体隐性遗传性早发帕金森病(EOPD)。目的:探讨EOPD白人家族PRKN突变的表现和基因型-表型关系。设计:对EOPD家族的3代20例成员进行基因分析,该家族有4例患者。应用直接基因组DNA测序、半定量聚合酶链反应、实时定量聚合酶链反应以及逆转录酶聚合酶链反应分析以确定PRKN突变。结果:4例早发患者(年龄30—38岁)被确定有PRKN复合杂合突变(T240M和EX5_6缺失),虽然PRKN的杂合T240M和纯合EX5_6缺失突变已有描述,但是据悉,本文为上述复合杂合突变的首次报道。患者的表型为典型常染色体隐性遗传性EOPD的表现,其特征是对左旋多巴治疗有效、相对缓慢的进展和运动障碍。所有杂合突变的基因携带者(T240M或EX5_6缺失)和1例56岁的复合杂合突变女性携带者(T240M和EX5_6缺失)无任何神经系统症状。结论:研究发现,PRKN基因复合杂合突变(T240M和EX5_6缺失)导致一个大的白人家族中4例成员发生常染色体隐性遗传性EOPD。另外1例成员具有相同的突变,比4例患者的平均发病年龄大10岁,并且无本病的临床表现。不完全的外显率对遗传咨询具有暗示作用,并且提示复杂的基因一环境交互作用在PRKN相关EOPD的发病机制中发挥作用。  相似文献   
10.
BACKGROUND: Despite major improvement in surgical techniques and intensive care management, stroke remains one of the most devastating complications of coronary artery bypass grafting (CABG). We aimed to determine factors predicting the occurrence of stroke during CABG. A special interest was focused on preoperative therapies. METHODS: We prospectively enrolled 810 consecutive candidates for CABG alone in a specific database, including all pre- and perioperative data (history, clinical, therapeutic, cardiac catheterization, surgical and intensive care data). Univariate tests and then multiple logistic regression analysis were used to determine independent predictive factors. RESULTS: During the first postoperative month, stroke occurred in 11 cases and transient ischemic attack (TIA) in 4 additive cases (cumulative rate: 1.85%). After the multivariate analysis, the following factors remained significant (p<0.05) in the predictive model, with corresponding odds ratios between brackets: redo cardiac surgery (7.45), unstable cardiac status (4.74), past history of cerebrovascular disease (4.14), past history of peripheral arterial disease (3.55), whereas the presence of preoperative statins was protective (0.24, 95% IC: 0.07-0.78). The addition of perioperative data (aortic calcification, postoperative arrhythmia, on/off-pump surgery) did not change the final predictive model. CONCLUSION: To our knowledge, this is the first real-world observational report highlighting the interest of statins for the prevention of stroke in the very special situation of CABG. Even though according to randomized trials coronary patients have a benefit from these drugs, a special level of interest should be directed towards those presenting the above-mentioned risk factors.  相似文献   
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