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   13024篇
  免费   827篇
  国内免费   60篇
耳鼻咽喉   144篇
儿科学   416篇
妇产科学   386篇
基础医学   1587篇
口腔科学   332篇
临床医学   1961篇
内科学   2052篇
皮肤病学   186篇
神经病学   1215篇
特种医学   409篇
外科学   1341篇
综合类   129篇
一般理论   14篇
预防医学   1662篇
眼科学   181篇
药学   1074篇
中国医学   16篇
肿瘤学   806篇
  2022年   64篇
  2021年   202篇
  2020年   120篇
  2019年   211篇
  2018年   253篇
  2017年   182篇
  2016年   188篇
  2015年   235篇
  2014年   356篇
  2013年   531篇
  2012年   746篇
  2011年   839篇
  2010年   493篇
  2009年   370篇
  2008年   722篇
  2007年   797篇
  2006年   783篇
  2005年   714篇
  2004年   668篇
  2003年   682篇
  2002年   704篇
  2001年   319篇
  2000年   337篇
  1999年   253篇
  1998年   153篇
  1997年   139篇
  1996年   98篇
  1995年   104篇
  1994年   95篇
  1993年   82篇
  1992年   183篇
  1991年   173篇
  1990年   169篇
  1989年   148篇
  1988年   154篇
  1987年   152篇
  1986年   131篇
  1985年   139篇
  1984年   95篇
  1983年   84篇
  1982年   68篇
  1981年   72篇
  1979年   90篇
  1978年   75篇
  1977年   64篇
  1976年   66篇
  1974年   58篇
  1973年   64篇
  1972年   57篇
  1970年   56篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Caring for patients with end-stage kidney disease (ESKD) in the United States is challenging, due in part to the complex epidemiology of the disease's progression as well as the ways in which care is delivered. As CKD progresses toward ESKD, the number of comorbidities increases and care involves multiple healthcare providers from multiple subspecialties. This occurs in the context of a fragmented US healthcare delivery system that is traditionally siloed by provider specialty, organization, as well as systems of payment and administration. This article describes the role of care fragmentation in the delivery of optimal ESKD care and identifies research gaps in the evidence across the continuum of care. We then consider the impact of care fragmentation on ESKD care from the patient and health system perspectives and explore opportunities for system-level interventions aimed at improving care for patients with ESKD.  相似文献   
2.
Introduction: Surgery in patients with head and neck cancers is frequently complicated by multiple stages of procedure that includes significant surgical removal of all or part of an organ with cancer, tissue reconstruction, and extensive neck dissection. Postoperative wound infections, termed ‘surgical site infections’ (SSIs) are a significant impediment to head-and-neck cancer surgery and recovery, and need to be addressed.

Areas covered: Approximately 10–45% of patients undergoing head-and-neck cancers surgery develop SSIs. SSIs can lead to delayed wound healing, increased morbidity and mortality as well as costs. Consequently, SSIs need to be avoided where possible, as even the surgery itself impacts on patients’ subsequent activities and their quality of life, which is exacerbated by SSIs. Several risk factors for SSIs need to be considered to reduce future rates, and care is also needed in the selection and duration of antibiotic prophylaxis.

Expert commentary: Head and neck surgeons should give personalized care especially to patients at high risk of SSIs. Such patients include those who have had chemoradiotherapy and need reconstructive surgery, and patients from lower and middle-income countries and from poorer communities in high income countries, who often have high levels of co-morbidity because of resource constraints.  相似文献   

3.
4.
Background. A persistent patent ductus arteriosus (PDA) may delay closure of a coexisting atrial septal defect (ASD) due to volume loading and enlargement of the left atrium. The purpose of this study was to investigate the natural history of ASD size in patients with a PDA following transcatheter PDA occlusion. Methods. All patients with an ASD and a PDA who underwent transcatheter PDA occlusion at Texas Children’s Hospital were identified. Patients with ASD diameter <3 mm, or additional cardiac defects were excluded. Eight patients (7 females) with small‐ to moderate‐sized ASDs and a PDA were identified. Patient demographics, echocardiographic data, and cardiac catheterization data were recorded. Data were analyzed by 1‐tailed t‐test. Results. Following PDA occlusion, ASD diameter decreased in 6 of 8 patients by a mean of 3.8 mm (±2.3 mm), including 2 that closed. The median duration of follow‐up was 689 days. One ASD remained unchanged and 1 increased in size. The mean maximum ASD diameter decreased from 6.4 mm (±2.2 mm) to 3.9 mm (±3.4 mm) (P = .03). Two patients underwent subsequent transcatheter ASD occlusion. Conclusion. Following transcatheter PDA occlusion, small‐ to moderate‐sized ASDs have significant probability to decrease in size, and possibly close. In infants and children, we recommend transcatheter PDA occlusion, and serial follow‐up of the size of the ASD. This will allow many small‐ to moderate‐sized ASDs to either close, or become smaller, obviating the need for future intervention.  相似文献   
5.
CONTEXT: Although the nonmedical use of stimulant drugs such as cocaine and methamphetamine is increasingly common in many rural areas of the United States, little is known about the health beliefs of people who use these drugs. PURPOSE: This research describes illicit stimulant drug users' views on health and health-related concepts that may affect their utilization of health care services. METHODS: A respondent-driven sampling plan was used to recruit 249 not-in-treatment, nonmedical stimulant drug users who were residing in 3 rural counties in west central Ohio. A structured questionnaire administered by trained interviewers was used to collect information on a range of topics, including current drug use, self-reported health status, perceived need for substance abuse treatment, and beliefs about health and health services. FINDINGS: Participants reported using a wide variety of drugs nonmedically, some by injection. Alcohol and marijuana were the most commonly used drugs in the 30 days prior to the interview. Powder cocaine was used by 72.3% of the sample, crack by 68.3%, and methamphetamine by 29.7%. Fair or poor health status was reported by 41.3% of the participants. Only 20.9% of the sample felt they needed drug abuse treatment. Less than one third of the sample reported that they would feel comfortable talking to a physician about their drug use, and 65.1% said they preferred taking care of their problems without getting professional help. CONCLUSIONS: Stimulant drug users in rural Ohio are involved with a range of substances and hold health beliefs that may impede health services utilization.  相似文献   
6.
Surfactant     
Surfactant, a complex substance containing specific proteins and phospholipids, is essential for gas exchange in the lungs. Research shows that surfactant not only lowers surface tension, but also plays a role in host defense. Surfactant replacement therapy is a cornerstone in the treatment of respiratory distress syndrome in premature infants. New information on endogenous surfactant composition including surfactant apoproteins has led to advances in the surfactant replacement products currently available. Because of the success of surfactant deficiency treatment in neonates, surfactant replacement therapy has been studied in both the pediatric and adult population for the treatment of other respiratory disorders. This article describes the composition, metabolism, and function of endogenous surfactant and other uses of surfactant replacement therapies in neonates.  相似文献   
7.
8.
9.
10.
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