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   2328篇
  免费   193篇
  国内免费   6篇
耳鼻咽喉   33篇
儿科学   45篇
妇产科学   40篇
基础医学   234篇
口腔科学   61篇
临床医学   202篇
内科学   780篇
皮肤病学   26篇
神经病学   243篇
特种医学   35篇
外科学   252篇
综合类   13篇
一般理论   1篇
预防医学   170篇
眼科学   26篇
药学   215篇
中国医学   3篇
肿瘤学   148篇
  2021年   32篇
  2020年   34篇
  2019年   37篇
  2018年   64篇
  2017年   48篇
  2016年   50篇
  2015年   60篇
  2014年   66篇
  2013年   99篇
  2012年   137篇
  2011年   124篇
  2010年   77篇
  2009年   77篇
  2008年   129篇
  2007年   118篇
  2006年   116篇
  2005年   137篇
  2004年   104篇
  2003年   101篇
  2002年   91篇
  2001年   54篇
  2000年   55篇
  1999年   36篇
  1998年   36篇
  1997年   22篇
  1996年   18篇
  1995年   23篇
  1994年   25篇
  1993年   15篇
  1992年   39篇
  1991年   43篇
  1990年   30篇
  1989年   26篇
  1988年   36篇
  1987年   22篇
  1986年   34篇
  1985年   25篇
  1984年   21篇
  1983年   26篇
  1982年   17篇
  1981年   17篇
  1980年   12篇
  1979年   17篇
  1978年   19篇
  1977年   19篇
  1976年   17篇
  1975年   14篇
  1973年   16篇
  1972年   11篇
  1971年   13篇
排序方式: 共有2527条查询结果,搜索用时 78 毫秒
1.
2.
3.
4.

Background

Many patients undergoing below knee amputations (BKA) return for subsequent unplanned operations, hospital readmission, or postoperative complications. This unplanned medical management negatively impacts both patient outcomes and our healthcare system. This study primarily investigates the risk factors for unplanned reoperation following BKA.

Methods

Below knee amputations from the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database from the years 2012–2014 were identified by CPT code 27880 for amputation through the tibia and fibula. Our query identified 4631 BKA cases, including 30 day complications. Multivariate logistic regression modeling was performed on several patient demographic and disease factors to assess for independent predictors of unplanned reoperation. Secondary outcomes of unplanned and related readmissions (related to the procedure), major complications, minor complications, and mortality were also included in the analysis.

Results

Of 4631 BKAs identified, 9.63% (446/4631) underwent unplanned reoperations and 8.75% (405/4631) had unplanned and related readmissions. Major complications were experienced by 12.8% (593/4631) and minor complications by 8.7% (401/4631). Thirty day mortality rate was 5.14% (238/4631). The most common procedures for unplanned operations were thigh amputations (128/446, 28.7%), debridement/secondary closure (114/446, 25.6%), and revision leg amputations (46/446, 10.32%). Factors associated with an increased risk of unplanned reoperation included patients transferred from another facility (Adjusted Odds Ratio [AOR]?=?1.28; p?=?.04), recent smokers (AOR?=?1.34; p?=?.02), bleeding disorder (AOR?=?1.30; p?=?.02), and preoperative ventilator use (AOR?=?2.38; p?=?.01).

Conclusion

Patients that were ongoing/recent smokers, had diagnosed bleeding disorders, required preoperative ventilator use, or were transferred in from another facility were associated with the highest risks of reoperation following BKA. This patient population experiences high rates of reoperation, readmission, complication, and mortality.  相似文献   
5.
6.
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   
7.
8.
Melatonin reduces nitric oxide synthase activity in rat hypothalamus   总被引:2,自引:0,他引:2  
Abstract: In this report, rat hypothalamic nitric oxide synthase (NOS) activity is shown to be partially inhibited by physiological concentrations of the pineal hormone melatonin. In vitro studies demonstrate that 1 nM melatonin, which approximates the physiological concentration of the hormone at night, significantly inhibited NOS activity. In vivo studies show that administering melatonin or collecting the hypothalamus from animals at night, when endogenous melatonin levels are elevated, results in a significant decrease of NOS activity. Results also show that calmodulin may be involved in this process since its presence in the incubation medium prevents the inhibitory effect of melatonin on NOS activity.  相似文献   
9.
Summary Plain radiography, myelography and post-myelographic CT-scan are described and related to clinical findings in a prospective study of 153 consecutive patients with myelographic signs of spinal cord compression. The majority of the metastatic tumours arise in the vertebral body or the pedicles. In 80% of the patients with total blockage to the contrast medium on myelography the post-myelographic-CT showed passage of the contrast medium. Ambulatory function at time of diagnosis was correlated to the degree and the localization of the epidural block. In 64 patients who underwent a second myelography, the post-treatment findings of sensory function were correlated to radiological regression.  相似文献   
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