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   8117篇
  免费   530篇
  国内免费   170篇
耳鼻咽喉   15篇
儿科学   210篇
妇产科学   98篇
基础医学   414篇
口腔科学   11篇
临床医学   793篇
内科学   2336篇
皮肤病学   29篇
神经病学   341篇
特种医学   77篇
外科学   1256篇
综合类   481篇
预防医学   2088篇
眼科学   11篇
药学   248篇
  6篇
中国医学   14篇
肿瘤学   389篇
  2024年   4篇
  2023年   212篇
  2022年   400篇
  2021年   570篇
  2020年   472篇
  2019年   419篇
  2018年   391篇
  2017年   307篇
  2016年   258篇
  2015年   260篇
  2014年   649篇
  2013年   576篇
  2012年   387篇
  2011年   545篇
  2010年   364篇
  2009年   430篇
  2008年   398篇
  2007年   336篇
  2006年   302篇
  2005年   257篇
  2004年   185篇
  2003年   147篇
  2002年   118篇
  2001年   108篇
  2000年   89篇
  1999年   75篇
  1998年   63篇
  1997年   59篇
  1996年   63篇
  1995年   63篇
  1994年   47篇
  1993年   39篇
  1992年   27篇
  1991年   35篇
  1990年   21篇
  1989年   13篇
  1988年   23篇
  1987年   20篇
  1986年   18篇
  1985年   18篇
  1984年   9篇
  1983年   5篇
  1982年   5篇
  1981年   5篇
  1980年   8篇
  1979年   4篇
  1978年   2篇
  1977年   2篇
  1974年   5篇
  1973年   2篇
排序方式: 共有8817条查询结果,搜索用时 15 毫秒
1.
Interventions that involve key aspects of community organizing, such as quantitative community assessments and organizational partnership support for the community, may promote residents' health. We evaluated the effectiveness of this form of intervention on mortality and its variability across individual-level household equivalized income tertiles, comparing 52,858 residents aged 65 and above in 12 intervention municipalities to 39,006 residents in nine control municipalities in Japan. During 1,166 days of follow-up, the adjusted hazard ratio for cumulative mortality among men in the intervention municipalities was 0.92 (95% confidence interval: 0.86, 0.99) compared to those in the control group, with similar results being observed across all income levels. Active utilization of data to evaluate communities and building intersectoral partnerships might lower older male residents’ mortality risk, regardless of their income status.  相似文献   
2.
《Injury》2023,54(6):1702-1710
IntroductionPatients with cirrhosis are at higher risk for morbidity after injury. Acetabular fractures represent a highly morbid injury pattern. Few studies have specifically examined an effect of cirrhosis on risk of complications after acetabular fracture. We hypothesized that cirrhosis is independently associated with increased risk of inpatient complications following operative treatment of acetabular fractures.MethodsAdults patients with acetabular fracture who underwent operative treatment were identified from Trauma Quality Improvement Program data from 2015 to 2019. Patients with and without cirrhosis were matched on a propensity score predicting cirrhotic status and inpatient complications based on patient, injury, and treatment characteristics. The primary outcome was overall complication rate. Secondary outcomes included serious adverse event rate, overall infection rate, and mortality.ResultsAfter propensity score matching, 137 cirrhosis+ and 274 cirrhosis- remained. No significant differences existed in observed characteristics after matching. Compared to cirrhosis- patients, cirrhosis+ patients experienced 43.4% (83.9 vs 40.5%, p < 0.001) greater absolute risk difference of any inpatient complication, 29.9% (51.8 vs 21.9%, p < 0.001) greater absolute risk difference of serious adverse events, 28.5% (41.6 vs 13.1%, p < 0.001) greater absolute risk difference of any infection, and 2.9% (2.9% vs 0.0%, p = 0.02) greater absolute risk difference of inpatient mortality.ConclusionCirrhosis is associated with higher rates of inpatient complications, serious adverse events, infection, and mortality among patients undergoing operative repair of acetabular fracture.Level of EvidencePrognostic Level III.  相似文献   
3.
《Clinical microbiology and infection》2022,28(8):1152.e1-1152.e6
ObjectivesDespite the possibility of concurrent infection with COVID-19 and malaria, little is known about the clinical course of coinfected patients. We analysed the clinical outcomes of patients with concurrent COVID-19 and malaria infection.MethodsWe conducted a retrospective cohort study that assessed prospectively collected data of all patients who were admitted between May and December 2020 to the Universal COVID-19 treatment center (UCTC), Khartoum, Sudan. UCTC compiled demographic, clinical, laboratory (including testing for malaria), and outcome data in all patients with confirmed COVID-19 hospitalized at that clinic. The primary outcome was all-cause mortality during the hospital stay. We built proportional hazard Cox models with malaria status as the main exposure and stepwise adjustment for age, sex, cardiovascular comorbidities, diabetes, and hypertension.ResultsWe included 591 patients with confirmed COVID-19 diagnosis who were also tested for malaria. Mean (SD) age was 58 (16.2) years, 446/591 (75.5%) were males. Malaria was diagnosed in 270/591 (45.7%) patients. Most malaria patients were infected by Plasmodium falciparum (140/270; 51.9%), while 121/270 (44.8%) were coinfected with Plasmodium falciparum and Plasmodium vivax. Median follow-up was 29 days. Crude mortality rates were 10.71 and 5.87 per 1000 person-days for patients with and without concurrent malaria, respectively. In the fully adjusted Cox model, patients with concurrent malaria and COVID-19 had a greater mortality risk (hazard ratio 1.43, 95% confidence interval 1.21-1.69).DiscussionCoinfection with COVID-19 and malaria is associated with increased all-cause in-hospital mortality compared to monoinfection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).  相似文献   
4.
5.
BackgroundWe aimed to assess mortality in chronic obstructive pulmonary disease (COPD), obstructive sleep apnea (OSA), and overlap syndrome, and evaluate which polysomnographic indices—apnea-hypopnea index (AHI) or hypoxemic load measurements—better predict mortality within 10 years.MethodsAdults with symptoms suggestive of sleep apnea and airway disease who underwent both polysomnography and spirometry plus bronchodilator response tests between 2000 and 2018 were included and divided into four groups according to presence of COPD and moderate-to-severe OSA (AHI ≥15/h). We estimated mortality using a Cox model adjusted for demographic/anthropometric covariates and comorbidities; this was called clinical model. To evaluate prognostic performance, we compared the concordance index (C-index) between clinical model and extended models, which incorporated one of polysomnographic indices—AHI, sleep time spent with SpO2 < 90% (TS90), and mean and lowest SpO2.ResultsAmong 355 participants, patients with COPD alone (57/355, 16.1%) and COPD–OSA overlap syndrome (37/355, 10.4%) had increased all-cause mortality than those who had neither disease (152/355, 42.8%) (adjusted HR, 2.98 and 3.19, respectively). The C-indices of extended models with TS90 (%) and mean SpO2 were significantly higher than that of clinical model (0.765 vs. 0.737 and 0.756 vs. 0.737, respectively; all P < 0.05); however, the C-index of extended model with AHI was not (0.739 vs. 0.737; P = 0.15).ConclusionsIn this cohort with symptoms of sleep apnea and airway disease, patients with overlap syndrome had increased mortality, but not higher than in those with COPD alone. The measurement of hypoxemic load, not AHI, better predicted mortality.  相似文献   
6.
BackgroundIn geriatric age group, hip fractures tend to become a major public health hazard. Due to this high occurrence, there is a need to develop standardized, effective, and multidisciplinary management for treatment. These elderly patients have excessive mortality that can extend ahead of the time of recovery. Early surgery after hip fractures has lead to a notable reduction in mortality rates. Still, it is considerably high as compared to other fractures.Methods266 patients of >65 years who were operated within 72 h hours in a tertiary level health care centre for hip fractures were included. They were evaluated with X-rays and grade of Singh’s index was noted. Mortality rates and the factors associated with it such as age, sex, co morbidities (using Charlson’s co morbidity Index/CCI) were evaluated after 2 year follow up.ResultsThe overall 2-year mortality reported in our study population was 11.2%. It was broadly lower as compared to most of the other studies. It was 6.3% in females as compared to 18.1% in males. While it was reported to be only 6% in 65–74 years of age, it was 25% in patients who were 85 years and above. 76.6% of the patients had Singh’s index of ≤ grade 3 showing osteoporosis. The patients with Low Charlson’s score showed only 4.2% mortality while those with high Charlson’s score showed 25.5% mortality.ConclusionIt was concluded that Mortality among elderly patients after early surgery after osteoporotic hip fractures is quite significant. The factors for improvement in long term survival post-hip fracture may include changing treatment patterns, increasing life expectancy and early surgery. Increase in age, female sex, and high CCI Scores were major risk factors of mortality after hip fractures in a 2-year follow-up period.  相似文献   
7.
8.
《Pancreatology》2022,22(5):665-670
Background and objectivesHyperlipasemia is highly prevalent among coronavirus disease 2019 (COVID-19) patients. The aim of this study was to assess the effect of lipase activity, measured at the time of admission, on the clinical course and mortality in COVID-19 patients.MethodsThe population of this study comprised 12,139 patients who were hospitalized due to COVID-19 between June 2020 and June 2021 in a pandemic hospital. Of these, 8819 patients were excluded from the study due to missing data, four patients were excluded due to a diagnosis of acute pancreatitis (according to the revised Atlanta criteria), and 72 patients were excluded due to alcohol use or having a history of chronic pancreatitis. The final study sample consisted of the remaining 3244 COVID-19 patients. Laboratory results, intensive care unit (ICU) follow-up periods, the need for mechanical ventilation, and mortality rates were compared between the normal lipase activity and high lipase activity groups.ResultsThere were 968 (29.8%) patients with high lipase activity at the time of admission. The rate of ICU admission was 36.1% vs. 9.9% (p < 0.001), mechanical ventilation requirement rates were 33.7% vs. 8.3% (p < 0.001), and mortality rates were as 24.6% vs. 6.4% (p < 0.001) in the high lipase activity group compared to the normal lipase activity group. Multivariate regression analysis revealed that high lipase activity was an independent factor in predicting mortality in hospitalized COVID-19 patients (odds ratio [OR]: 3.191, p < 0.001).ConclusionElevated lipase activity without acute pancreatitis at the time of admission in COVID-19 patients was determined as an independent predictor of poor prognosis.  相似文献   
9.
10.
目的分析江苏省启东市1972—2016年胃癌死亡流行特征。方法收集启东市1972—2016年恶性肿瘤死亡登记数据库及历年人口资料, 计算死亡率、中国人口标化率(中标率)、世界人口标化率(世标率)、35~64岁截缩率、0~74岁累积死亡率、累积死亡风险、变化百分比、死亡率年均变化百分比。结果 1972—2016年启东市胃癌死亡例数为15 863例, 占全部恶性肿瘤死亡例数的16.04%, 胃癌死亡率为31.37/10万, 中标率为12.97/10万, 世标率为21.39/10万, 35~64岁截缩死亡率为28.86/10万, 0~74岁累积死亡率为2.54%, 胃癌死亡累积风险为2.51%。男性死亡10 114例, 男性死亡率、中标率、世标率分别为40.53/10万、17.98/10万和30.13/10万;女性死亡5 749例, 女性死亡率、中标率、世标率分别为22.45/10万、8.52/10万和13.92/10万。25岁以下各年龄组的死亡率<1/10万, 死亡率随年龄的增长而升高, 50~岁组达到并超过人群的平均死亡率水平, 80~岁组达到死亡高峰。1972—2016年间胃癌死...  相似文献   
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