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   5911篇
  免费   456篇
  国内免费   122篇
耳鼻咽喉   142篇
儿科学   152篇
妇产科学   50篇
基础医学   337篇
口腔科学   276篇
临床医学   587篇
内科学   555篇
皮肤病学   191篇
神经病学   107篇
特种医学   97篇
外科学   467篇
综合类   642篇
一般理论   1篇
预防医学   278篇
眼科学   1072篇
药学   1323篇
  2篇
中国医学   95篇
肿瘤学   115篇
  2024年   4篇
  2023年   72篇
  2022年   101篇
  2021年   196篇
  2020年   207篇
  2019年   204篇
  2018年   230篇
  2017年   211篇
  2016年   183篇
  2015年   213篇
  2014年   328篇
  2013年   674篇
  2012年   365篇
  2011年   315篇
  2010年   260篇
  2009年   275篇
  2008年   260篇
  2007年   254篇
  2006年   251篇
  2005年   199篇
  2004年   202篇
  2003年   182篇
  2002年   162篇
  2001年   112篇
  2000年   100篇
  1999年   81篇
  1998年   63篇
  1997年   67篇
  1996年   72篇
  1995年   50篇
  1994年   48篇
  1993年   53篇
  1992年   43篇
  1991年   35篇
  1990年   33篇
  1989年   46篇
  1988年   35篇
  1987年   28篇
  1986年   21篇
  1985年   50篇
  1984年   40篇
  1983年   35篇
  1982年   28篇
  1981年   29篇
  1980年   25篇
  1979年   8篇
  1978年   8篇
  1977年   14篇
  1976年   8篇
  1975年   3篇
排序方式: 共有6489条查询结果,搜索用时 31 毫秒
1.
The research and development of penicillin started with difficulty before 1949 and achieved certain results. In 1951, after the founding of the People's Republic of China, Zhang Weishen, as the only Chinese scientist who had been trained and worked in a penicillin research and development center in the United States for many years, overcame many difficulties and returned to China. In 1953, with the efforts of Zhang Weishen and his colleagues, China realized the industrialized production of penicillin, alleviating the urgent needs of the masses. Antibiotics has also become the first discipline to achieve major scientific and technological achievements after the founding of the New China. In the mid-1950s, the technical breakthrough in the localization of lactose substitutes marked the localization of the raw materials of the penicillin-producing culture medium, which paved the way for the industrialized production of penicillin with Chinese characteristics. Antibiotics have become one of the most widely used and affordable drugs for hundreds of millions of patients in China, and China has since ended the humiliating history of the “Sick Man of East Asia".  相似文献   
2.
BackgroundWe aimed to describe the effectiveness and safety of inhaled antibiotics in chronic obstructive pulmonary disease (COPD) patients, as well as the patient profile in which they are usually prescribed and the patient groups that can most benefit from this treatment.MethodsMulticentre retrospective observational cohort study in COPD patients who had received ≥1 dose of inhaled antibiotics in the last 5 years. Clinical data from the two years prior to and subsequent to the start of the treatment were compared. Primary outcome: COPD exacerbations. Secondary outcomes: side effects, symptomatology (sputum purulence, dyspnoea), microbiological profile and pathogen eradication.ResultsOf 693 COPD patients analyzed (aged 74.1; 86.3% men; mean FEV1 = 43.7%), 71.7% had bronchiectasis and 46.6% presented chronic bronchial infection (CBI) by Pseudomonas aeruginosa (PA). After 1 year of treatment with inhaled antibiotics, there was a significant decrease in the number of exacerbations (?33.3%; P < .001), hospital admissions (?33.3%; P < .001) and hospitalization days (?26.2%; P = .003). We found no difference in effectiveness between patients with or without associated bronchiectasis. Positive patient outcomes were more pronounced in PA-eradicated patients. We found a significant reduction in daily expectoration (?33.1%; P = .024), mucopurulent/purulent sputum (?53.9%; P < .001), isolation of any potentially pathogenic microorganisms (PPM) (?16.7%; P < .001), CBI by any PPM (?37.4%; P < .001) and CBI by PA (?49.8%; P < .001). CBI by any PPM and ≥three previous exacerbations were associated with a better treatment response. 25.4% of patients presented non-severe side-effects, the most frequent of these being bronchospasm (10.5%), dyspnoea (8.8%) and cough (1.7%).ConclusionsIn COPD patients with multiple exacerbations and/or CBI by any PPM (especially PA), inhaled antibiotics appear to be an effective and safe treatment, regardless of the presence of bronchiectasis.  相似文献   
3.
This study was undertaken to evaluate the infection rate following orthognathic surgery and to identify possible risk factors. A retrospective study was conducted. Patients undergoing orthognathic surgery from August 1, 2017 to July 31, 2018 were included. The outcome variable was surgical site infection (SSI). All data were analysed with respect to demographics and procedure specifications. A total of 137 patients (mean age 28.5 ± 12.69 years) were included in this study, of whom 20 (14.6%) developed a SSI. The only risk factor identified was the type of surgery: those undergoing mandibular osteotomies (in bilateral sagittal split osteotomy (BSSO) or bimaxillary osteotomies) were far more likely to develop infections. Third molar teeth were removed during orthognathic surgery in 28.5% of the procedures, and a genioplasty was performed in 10.9%. Removal of osteosynthesis material because of infectious reasons was necessary in 10.2% of patients, with a strong association to previous SSI. In conclusion, this study showed an infection rate of 14.6% with no link to any demographic risk factor. Neither the simultaneous removal of third molar teeth nor genioplasty was found to be a risk factor for SSI. For literature comparison purposes, there is a clear need for the international guidelines defining SSI to be used.  相似文献   
4.
5.
6.
7.
8.
9.
Infection remains the Achilles heel of left ventricular assist device (LVAD) therapy. However, an optimal antimicrobial surgical infection prophylaxis (SIP) regimen has not been established. This study evaluated the efficacy of a single‐drug SIP compared to a multi‐drug SIP on clinical outcomes in patients undergoing continuous‐flow LVAD (CF‐LVAD) and pulsatile LVAD (P‐LVAD) implantation. An electronic search was performed to identify studies in the English literature on SIP regimens in patients undergoing LVAD implantation. Identified articles were assessed for inclusion and exclusion criteria. Fourteen articles with 1,311 (CF‐LVAD: 888; P‐LVAD: 423) patients were analyzed. Overall, 501 (38.0%) patients received single‐drug SIP, whereas 810 (62.0%) received multi‐drug SIP. Time to infection was comparable between groups. There was no significant difference in overall incidence of LVAD‐specific infections [single‐drug: 18.7% vs. multi‐drug: 24.8%, P = 0.49] including driveline infections [single‐drug: 14.1% vs. multi‐drug: 20.8%, P = 0.37]. Compared to single‐drug SIP, patients who received multi‐drug SIP had a significantly lower survival rate [single‐drug: 90.0% vs. multi‐drug: 76.0%, P = 0.01] and infection‐free survival rate [single‐drug: 88.4% vs. multi‐drug: 77.3%, P = 0.04] at 90 days. However, there were no significant differences in 1‐year survival and 1‐year infection‐free survival between groups. No survival differences were observed in the CF‐LVAD subset as well. This study demonstrated no additional advantage of a multi‐drug compared to a single‐drug regimen for SIP. Although there was a modest advantage in early survival among CF‐LVAD and P‐LVAD patients who received single‐drug SIP, there were no significant differences in the 1‐year survival and 1‐year infection‐free survival.  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