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   35240篇
  免费   6659篇
  国内免费   244篇
耳鼻咽喉   808篇
儿科学   907篇
妇产科学   877篇
基础医学   2508篇
口腔科学   2984篇
临床医学   5442篇
内科学   7770篇
皮肤病学   984篇
神经病学   2935篇
特种医学   1606篇
外科学   5798篇
综合类   109篇
现状与发展   12篇
一般理论   2篇
预防医学   3322篇
眼科学   695篇
药学   1512篇
中国医学   193篇
肿瘤学   3679篇
  2024年   170篇
  2023年   1183篇
  2022年   668篇
  2021年   1136篇
  2020年   1481篇
  2019年   835篇
  2018年   1719篇
  2017年   1615篇
  2016年   1975篇
  2015年   2196篇
  2014年   2691篇
  2013年   3167篇
  2012年   2047篇
  2011年   1887篇
  2010年   2066篇
  2009年   2560篇
  2008年   1558篇
  2007年   1334篇
  2006年   1365篇
  2005年   1109篇
  2004年   863篇
  2003年   724篇
  2002年   658篇
  2001年   685篇
  2000年   564篇
  1999年   594篇
  1998年   569篇
  1997年   541篇
  1996年   570篇
  1995年   441篇
  1994年   327篇
  1993年   280篇
  1992年   256篇
  1991年   221篇
  1990年   218篇
  1989年   209篇
  1988年   186篇
  1987年   169篇
  1986年   148篇
  1985年   137篇
  1984年   105篇
  1983年   122篇
  1982年   97篇
  1981年   91篇
  1980年   64篇
  1979年   69篇
  1978年   76篇
  1977年   68篇
  1975年   57篇
  1974年   51篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Scrub typhus usually presents as acute undifferentiated fever. This cross-sectional study included adult patients presenting with acute undifferentiated fever defined as any febrile illness for ≤ 14 days without evidence of localized infection. Scrub typhus cases were defined by an antibody titer of a ≥ fourfold increase in paired sera, a ≥ 1:160 in a single serum using indirect immunofluorescence assay, or a positive result of the immunochromatographic test. Multiple regression analysis identified predictors associated with scrub typhus to develop a prediction rule. Of 250 cases with known etiology of acute undifferentiated fever, influenza (28.0%), hepatitis A (25.2%), and scrub typhus (16.4%) were major causes. A prediction rule for identifying suspected cases of scrub typhus consisted of age ≥ 65 years (two points), recent fieldwork/outdoor activities (one point), onset of illness during an outbreak period (two points), myalgia (one point), and eschar (two points). The c statistic was 0.977 (95% confidence interval = 0.960–0.994). At a cutoff value ≥ 4, the sensitivity and specificity were 92.7% (79.0–98.1%) and 90.9% (86.0–94.3%), respectively. Scrub typhus, the third leading cause of acute undifferentiated fever in our region, can be identified early using the prediction rule.  相似文献   
3.
This retrospective study aimed to evaluate radiation-induced pneumonitis (RIP) and a related condition that we define in this report—prolonged minimal RIP (pmRIP)—after stereotactic body radiotherapy (SBRT) for Stage I primary lung cancer in patients with chronic obstructive pulmonary disease (COPD). We assessed 136 Stage I lung cancer patients with COPD who underwent SBRT. Airflow limitation on spirometry was classified into four Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades, with minor modifications: GOLD 1 (mild), GOLD 2 (moderate), GOLD 3 (severe) and GOLD 4 (very severe). On this basis, we defined two subgroups: COPD-free (COPD −) and COPD-positive (COPD +). There was no significant difference in overall survival or cause-specific–survival between these groups. Of the 136 patients, 44 (32%) had pmRIP. Multivariate analysis showed that COPD and the Brinkman index were statistically significant risk factors for the development of pmRIP. COPD and the Brinkman index were predictive factors for pmRIP, although our findings also indicate that SBRT can be tolerated in early lung cancer patients with COPD.  相似文献   
4.
5.
The association between asbestos exposure, mainly in occupational settings, and malignant mesothelioma has been well established; this has prompted several countries to establish mesothelioma epidemiologic surveillance programs often at the request of national agencies. This review compares currently existing mesothelioma registries worldwide to develop a concept model for a US real-time case capture mesothelioma registry. Five countries were identified with a mesothelioma specific registry, including Italy, France, UK, Australia, and South Korea. All, except the UK, used interviews to collect exposure data. Linkage with the national death index was available or was in future plans for all registries. The registries have limited information on treatment, quality of life, and other patient-centered outcomes such as symptoms and pain management. To thoroughly collect exposure data, “real-time” enrollment is preferable; to maximize the capture of mesothelioma cases, optimal coverage, and a simplified consent process are needed.  相似文献   
6.
7.
8.

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   
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