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   219113篇
  免费   17368篇
  国内免费   7005篇
耳鼻咽喉   1253篇
儿科学   7709篇
妇产科学   1558篇
基础医学   19412篇
口腔科学   3604篇
临床医学   23226篇
内科学   55506篇
皮肤病学   2716篇
神经病学   26059篇
特种医学   6296篇
外国民族医学   4篇
外科学   16861篇
综合类   30036篇
现状与发展   31篇
一般理论   9篇
预防医学   17846篇
眼科学   2383篇
药学   15100篇
  186篇
中国医学   9964篇
肿瘤学   3727篇
  2024年   523篇
  2023年   4367篇
  2022年   7562篇
  2021年   11725篇
  2020年   10942篇
  2019年   8324篇
  2018年   8246篇
  2017年   8178篇
  2016年   8510篇
  2015年   8211篇
  2014年   15588篇
  2013年   17020篇
  2012年   12754篇
  2011年   13800篇
  2010年   10855篇
  2009年   10433篇
  2008年   10454篇
  2007年   10107篇
  2006年   9006篇
  2005年   7444篇
  2004年   6325篇
  2003年   5433篇
  2002年   4577篇
  2001年   3959篇
  2000年   3298篇
  1999年   2829篇
  1998年   2704篇
  1997年   2386篇
  1996年   2136篇
  1995年   1933篇
  1994年   1775篇
  1993年   1516篇
  1992年   1454篇
  1991年   1279篇
  1990年   1012篇
  1989年   859篇
  1988年   805篇
  1987年   733篇
  1986年   633篇
  1985年   736篇
  1984年   617篇
  1983年   380篇
  1982年   447篇
  1981年   374篇
  1980年   282篇
  1979年   247篇
  1978年   184篇
  1977年   164篇
  1976年   135篇
  1975年   49篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
101.
Objective: Longitudinal data on cardiometabolic effects of egg intake during adolescence are lacking. The current analyses aim to evaluate the impact of usual adolescent egg consumption on lipid levels, fasting glucose, and insulin resistance during late adolescence (age 17–20?years).

Methods: Data from 1392 girls, aged 9 to 10 at baseline and followed for 10?years, in the National Heart, Lung, and Blood Institute’s National Growth and Health Study were used to examine the association between usual egg intake alone and in combination with other healthy lifestyle factors and late adolescent lipid levels, fasting glucose, and insulin resistance, measured as homeostasis model assessment of insulin resistance (HOMA-IR). Diet was assessed using 3-day food records during eight examination cycles. Girls were classified according to usual weekly egg intake, ages 9–17?years:?<1 egg/wk (n?=?361), 1 to <3 eggs/wk (n?=?703), and ≥3 eggs/wk (n?=?328). Analysis of covariance modeling was used to control for confounding by other behavioral and biological risk factors.

Results: Girls with low, moderate, and high egg intakes had adjusted low-density lipoprotein cholesterol levels of 99.7, 98.8, and 95.5 mg/dL, respectively (p?=?0.0778). In combination with higher intakes of fiber, dairy, or fruits and vegetables, these beneficial effects were stronger and statistically significant. There was no evidence that ≥3 eggs/wk had an adverse effect on lipids, glucose, or HOMA-IR. More active girls who consumed ≥3 eggs/wk had the lowest levels of insulin resistance.

Conclusion: These results suggest that eggs may be included as part of a healthy adolescent diet without adverse effects on glucose, lipid levels, or insulin resistance.  相似文献   

102.
103.
104.
105.
IntroductionEndoscopic surveillance guidelines for patients with repaired esophageal atresia (EA) rely primarily on expert opinion. Prior to embarking on a prospective EA surveillance registry, we sought to understand EA surveillance practices within the Eastern Pediatric Surgery Network (EPSN).MethodsAn anonymous, 23-question Qualtrics survey was emailed to 181 physicians (surgeons and gastroenterologists) at 19 member institutions. Likert scale questions gauged agreement with international EA surveillance guideline-derived statements. Multiple-choice questions assessed individual and institutional practices.ResultsThe response rate was 77%. Most respondents (80%) strongly agree or agree that EA surveillance endoscopy should follow a set schedule, while only 36% claimed to perform routine upper GI endoscopy regardless of symptoms. Many institutions (77%) have an aerodigestive clinic, even if some lack a multi-disciplinary EA team. Most physicians (72%) expressed strong interest in helping develop evidence-based guidelines.ConclusionsOur survey reveals physician agreement with current guidelines but weak adherence. Surveillance methods vary greatly, underscoring the lack of evidence-based data to guide EA care. Aerodigestive clinics may help implement surveillance schedules. Respondents support evidence-based protocols, which bodes well for care standardization. Results will inform the first multi-institutional EA databases in the United States (US), which will be essential for evidence-based care.Level of EvidenceThis is a prognosis study with level 4 evidence.  相似文献   
106.
107.
108.
First described in 1955 in New Jersey, epizootic haemorrhagic disease (EHD) causes a severe clinical disease in wild and domestic ruminants worldwide. Epizootic haemorrhagic disease outbreaks occur in deer populations each year from summer to late autumn. The etiological agent is EHD virus (EHDV) which is a double‐stranded segmented icosahedral RNA virus. EHD virus utilizes point mutations and reassortment strategies to maintain viral fitness during infection. In 2018, EHDV serotype 2 was predominantly detected in deer in Illinois. Whole genome sequencing was conducted for two 2018 EHDV2 isolates (IL41747 and IL42218) and the sequence analyses indicated that IL42218 was a reassortant between different serotypes whereas IL41747 was a genetically stable strain. Our data suggest that multiple strains contribute to outbreaks each year.  相似文献   
109.
110.
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