全文获取类型
收费全文 | 25859篇 |
免费 | 1624篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 179篇 |
儿科学 | 809篇 |
妇产科学 | 618篇 |
基础医学 | 3893篇 |
口腔科学 | 450篇 |
临床医学 | 3719篇 |
内科学 | 4690篇 |
皮肤病学 | 439篇 |
神经病学 | 2702篇 |
特种医学 | 600篇 |
外科学 | 2101篇 |
综合类 | 173篇 |
一般理论 | 26篇 |
预防医学 | 2998篇 |
眼科学 | 445篇 |
药学 | 1869篇 |
1篇 | |
中国医学 | 56篇 |
肿瘤学 | 1796篇 |
出版年
2024年 | 23篇 |
2023年 | 211篇 |
2022年 | 387篇 |
2021年 | 714篇 |
2020年 | 467篇 |
2019年 | 635篇 |
2018年 | 773篇 |
2017年 | 549篇 |
2016年 | 608篇 |
2015年 | 789篇 |
2014年 | 907篇 |
2013年 | 1452篇 |
2012年 | 2022篇 |
2011年 | 2169篇 |
2010年 | 1128篇 |
2009年 | 1057篇 |
2008年 | 1760篇 |
2007年 | 1828篇 |
2006年 | 1778篇 |
2005年 | 1662篇 |
2004年 | 1571篇 |
2003年 | 1442篇 |
2002年 | 1266篇 |
2001年 | 166篇 |
2000年 | 126篇 |
1999年 | 171篇 |
1998年 | 220篇 |
1997年 | 168篇 |
1996年 | 161篇 |
1995年 | 116篇 |
1994年 | 125篇 |
1993年 | 106篇 |
1992年 | 72篇 |
1991年 | 86篇 |
1990年 | 71篇 |
1989年 | 78篇 |
1988年 | 47篇 |
1987年 | 47篇 |
1986年 | 47篇 |
1985年 | 49篇 |
1984年 | 67篇 |
1983年 | 72篇 |
1982年 | 70篇 |
1981年 | 48篇 |
1980年 | 50篇 |
1979年 | 34篇 |
1978年 | 22篇 |
1977年 | 25篇 |
1976年 | 24篇 |
1974年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Talita da Silva Mendes de Farias Ariclécio Cunha de Oliveira Sandra Andreotti Fernanda Gaspar do Amaral Patrícia Chimin André Ricardo Alves de Proença Francisco Leonardo Torres Leal Rogério Antonio Laurato Sertié Amanda Baron Campana Andressa Bolsoni Lopes Arnaldo Henrique de Souza José Cipolla‐Neto Fabio Bessa Lima 《Journal of pineal research》2015,58(3):251-261
Melatonin, the main hormone produced by the pineal gland, is secreted in a circadian manner (24‐hr period), and its oscillation influences several circadian biological rhythms, such as the regulation of clock genes expression (chronobiotic effect) and the modulation of several endocrine functions in peripheral tissues. Assuming that the circadian synchronization of clock genes can play a role in the regulation of energy metabolism and it is influenced by melatonin, our study was designed to assess possible alterations as a consequence of melatonin absence on the circadian expression of clock genes in the epididymal adipose tissue of male Wistar rats and the possible metabolic repercussions to this tissue. Our data show that pinealectomy indeed has impacts on molecular events: it abolishes the daily pattern of the expression of Clock, Per2, and Cry1 clock genes and Pparγ expression, significantly increases the amplitude of daily expression of Rev‐erbα, and affects the pattern of and impairs adipokine production, leading to a decrease in leptin levels. However, regarding some metabolic aspects of adipocyte functions, such as its ability to synthesize triacylglycerols from glucose along 24 hr, was not compromised by pinealectomy, although the daily profile of the lipogenic enzymes expression (ATP‐citrate lyase, malic enzyme, fatty acid synthase, and glucose‐6‐phosphate dehydrogenase) was abolished in pinealectomized animals. 相似文献
3.
4.
Thomas S. Klitzner Maggie Lee Sandra Rodriguez Ruey‐Kang R. Chang 《Congenital heart disease》2006,1(3):77-88
Background. It has been reported that gender differences in cardiovascular outcomes found in adults also are present in children who undergo surgical repair for congenital heart disease. Methods. California statewide hospital discharge data 1989–99 were used to study outcomes in children <18 years undergoing cardiac surgery. Hospital discharge data were linked to death registry data to study postdischarge death within 30 days of discharge. We used logistic regression to evaluate the effect of gender on mortality controlling for age, race and ethnicity, type of insurance, household income, date and month of surgery, type of admission, hospital case volume, and various types of procedures. Results. There were 25 402 cardiac surgery cases with 1505 in‐hospital deaths (mortality rate of 5.92%). An additional 37 deaths occurred within 30 days after hospital discharge. Crude mortality rates for males (5.99%) and females (5.84%) were not significantly different. However, fewer neonates were female and females underwent a higher proportion of low‐risk procedures than males. Logistic regression revealed that females, compared with males, had a significantly higher odds ratio (OR) for in‐hospital mortality (OR = 1.18, P < .01) and overall (up to 30 days post discharge) mortality (OR = 1.18, P < .01). The risk‐adjusted length of hospital stay was similar between females and males while charges per hospital day were slightly higher in females than males. The prevalence of Down syndrome, pulmonary hypertension, and failure to thrive were higher in females. Conclusions. Female gender is associated with an 18% higher in‐hospital and 30‐day postdischarge mortality as compared with male gender. There was no difference in length of hospital stay between males and females. The mechanism by which female gender acts as a risk factor requires further investigation. 相似文献
5.
6.
BACKGROUND: The 1997 National Asthma Education and Prevention Program (NAEPP) recommends a severity classification scheme to optimize the use of anti-inflammatory therapy for persistent asthma. Physician documentation of asthma severity is often used as a quality assurance measure. OBJECTIVE: To test the hypothesis that physician documentation of asthma severity is associated with appropriate use of anti-inflammatory therapy. DESIGN/METHODS: Setting: inner-city academic health center. First, we reviewed a consecutive sample of charts of scheduled pediatric patients. Then, we administered a structured parent survey regarding the child's asthma symptoms and current asthma therapy. We used NAEPP guidelines to classify patients' severity of asthma. The main outcome measure was appropriate use of anti-inflammatory therapy. Appropriate therapy was defined as: (1) mild persistent asthmatics using anti-inflammatory therapy, and (2) moderate-severe persistent asthmatics using inhaled steroids. Chart classification of asthma severity was compared with the NAEPP-applied classification. RESULTS: Of 784 charts, 214 (27%) were asthmatic. Of these, 176 (82%) were surveyed. The mean age was 7.4 years; 61% were males. Severity classification was documented in 77% of charts. Chart documentation differed significantly from survey classification for the same patients: (mild intermittent 54% vs. 40%, mild persistent 21% vs. 14%, moderate persistent 24% vs. 36%, severe persistent 1% vs. 10%; all p < .001). Correctly classified patients were more likely to be on appropriate therapy. CONCLUSIONS: Physicians underestimated the severity classification of asthmatic patients. Incorrect classification was associated with inappropriate asthma therapy. These findings have implications for the institution of asthma quality improvement programs. 相似文献
7.
8.
The use of computer technology for patient education has increased in recent years. This article describes a study that measures the attitudes and perceptions of healthcare professionals and laypeople regarding the effectiveness of a multimedia computer, the Brain Injury Resource Center? (BIRC), as an educational tool. The study focused on three major themes: (a) usefulness of the information presented, (b) effectiveness of the multimedia touch-screen computer methodology, and (c) the appropriate time for making this resource available. This prospective study, conducted in an acute care medical center, obtained healthcare professionals' evaluations using a written survey and responses from patients with brain injury and their families during interviews. The findings have yielded excellent ratings as to the ease of understanding and usefulness of the BIRC. By using sight, sound, and touch, such a multimedia learning center has the potential to simplify patient and family education. 相似文献
9.
10.