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   130085篇
  免费   7303篇
  国内免费   922篇
耳鼻咽喉   776篇
儿科学   3101篇
妇产科学   3993篇
基础医学   14172篇
口腔科学   4197篇
临床医学   14454篇
内科学   27449篇
皮肤病学   1719篇
神经病学   13757篇
特种医学   5353篇
外国民族医学   2篇
外科学   16906篇
综合类   2556篇
现状与发展   3篇
一般理论   32篇
预防医学   9073篇
眼科学   1917篇
药学   7141篇
  27篇
中国医学   1023篇
肿瘤学   10659篇
  2024年   201篇
  2023年   8027篇
  2022年   11506篇
  2021年   11446篇
  2020年   12288篇
  2019年   6924篇
  2018年   5522篇
  2017年   6512篇
  2016年   6040篇
  2015年   5380篇
  2014年   11148篇
  2013年   7315篇
  2012年   4758篇
  2011年   3503篇
  2010年   6192篇
  2009年   5691篇
  2008年   2424篇
  2007年   2560篇
  2006年   2091篇
  2005年   1683篇
  2004年   1319篇
  2003年   1342篇
  2002年   1325篇
  2001年   1314篇
  2000年   1093篇
  1999年   1336篇
  1998年   1165篇
  1997年   895篇
  1996年   970篇
  1995年   938篇
  1994年   676篇
  1993年   542篇
  1992年   503篇
  1991年   429篇
  1990年   434篇
  1989年   397篇
  1988年   312篇
  1987年   191篇
  1986年   122篇
  1985年   163篇
  1984年   183篇
  1983年   168篇
  1982年   151篇
  1981年   170篇
  1980年   151篇
  1979年   122篇
  1978年   84篇
  1977年   86篇
  1976年   74篇
  1974年   61篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
BackgroundLeft ventricular unloading with Impella may improve survival outcomes in patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS). However, the optimal timing to initiate left ventricular unloading has yet to be established. Therefore, we conducted a systematic review and meta-analysis to compare survival in patients with AMI-CS who were supported with Impella prior to PCI (pre-PCI) to those in whom support was initiated following PCI (post-PCI).MethodsAll studies that evaluated the impact of pre-PCI versus post-PCI Impella placement in patients with AMI-CS were included. Primary endpoints included in-hospital, 30-day, and 6-month survival rates.ResultsWe identified five observational studies comparing outcomes in 432 patients with AMI-CS, of which 173 patients were treated with Impella pre-PCI and 259 patients post-PCI. Patients in the pre-PCI group had lower in-hospital mortality compared to patients in the post-PCI group (RR 0.62, 95% CI: 0.50–0.76, I2 = 0%). The lower mortality rate in the pre-PCI group remained evident at 30 days (HR 0.60, 95% CI: 0.47–0.78, I2 = 0%) and at 6 months (HR 0.66, 95% CI: 0.44–0.97, I2 = 0%). There was no difference in the risk of adverse events including reinfarction, stroke, major bleeding, acute ischemic limb, access site bleeding, and hemolysis.ConclusionsIn this meta-analysis of studies evaluating survival among AMI-CS patients with left ventricular unloading initiated pre- versus post-PCI, Impella placement prior to PCI was associated with improved survival.  相似文献   
22.
BackgroundThe clinical importance of postoperative hyperamylasemia (POHA) grade is unknown. Our objectives were to evaluate the association of POHA grade with clinically relevant postoperative pancreatic fistula (CR-POPF) and compare its prognostic utility against postoperative day 1 drain fluid amylase (DFA-1).MethodsPatients who underwent pancreatectomy from January 2019 through March 2020 were identified in the ACS NSQIP pancreatectomy-targeted dataset. POHA grade was assigned using post-operative serum amylase and clinical sequelae. The primary outcome was CR-POPF within 30 days. The association of POHA grade with CR-POPF was assessed using multivariable logistic regression, and c-statistics were used to compare POHA grade versus DFA-1.ResultsPOHA occurred in 520 patients at 98 hospitals, including 261 (50.2%) with grade A, 234 (45.0%) with grade B, and 25 (4.8%) with grade C POHA. CR-POPFs were increased among patients with grade B (66.2%, OR 9.28 [5.84–14.73]) and C (68.0%, OR 10.50 [3.77–29.26]) versus grade A POHA (19.2%). POHA-inclusive models better predicted CR-POPF than those with DFA-1 alone (p < 0.002) and models with both predictors outperformed POHA alone (p = 0.039).ConclusionPOHA grade represents a measure of post-pancreatectomy outcomes that predicts CR-POPF and outperforms DFA-1 but must be aligned with new international definitions.  相似文献   
23.
肠易激综合征是临床常见的功能性胃肠病之一。由于多数患者的症状经过一线药物治疗后仍不能得到较好改善,许多患者为获得更好的治疗效果,转向选择补充与替代疗法进行治疗。然而,由于研究质量和数量的限制,大部分治疗肠易激综合征的补充与替代疗法并未被相关共识和指南所推荐。本文从补充与替代疗法的分类入手,从天然产品、身心治疗、传统医药3个方面就目前国内外常用的补充与替代疗法治疗肠易激综合征的研究进行概述,以期为临床工作者和患者更好地了解和应用提供帮助。  相似文献   
24.
25.
BackgroundAlthough there are many treatments for laryngeal contact granuloma (LCG), some patients still fail treatment. Botulinum toxin A injection vocal cords may be a salvage therapy.ObjectivesTo study the efficacy of thyroarytenoid botulinum toxin A injection for the treatment of refractory LCG.Material and methodsFrom May 2021 to March 2022, 23 male patients with refractory idiopathic LCG were treated by injection of botulinum toxin A into the thyroarytenoid muscle via the thyrohyoid membrane approach. Inspiratory-phase laryngoscopy images were collected before treatment and 3 months after injection treatment. The lesion size was evaluated with the Farwell granuloma endoscopic grading system and Image J software.ResultsThe average age of 23 patients was 49 years. The dose of botulinum toxin injection ranged from 2.5 to 5 units. Three months after injection, 17 patients were cured, 2 patients showed marked improvement, and 4 patients did not experience any effect. The total efficacy rate was 82.61% (19/23), and no serious complications occurred. Almost all patients experienced hoarseness within one week after injection; they gradually recovered after one month, and their voice returned to baseline at 3 months.ConclusionsThyroarytenoid botulinum toxin injection is an effective method for resolving refractory LCG.  相似文献   
26.
27.
28.
《Vaccine》2022,40(52):7515-7519
The recent wave of COVID-19 cases has led to the potential need for booster doses. We surveyed 6,294 people and found that 87.6% reported willingness to take a booster dose, with vaccine efficacy rate being the most common reason cited to accept booster dose. Differences in acceptance rates were noted among those working in non-health related sectors, different ethnic groups as well as those who had taken viral vector vaccines.  相似文献   
29.
《Ophthalmology》2022,129(4):366-368
  相似文献   
30.
ObjectiveThere may be gender difference in correlation of diabetes mellitus (DM) and cardiovascular events. We attempt to investigate whether there is gender-heterogeneity in one-year outcomes of atrial fibrillation (AF) patients with DM or not.MethodsPatients who were diagnosed with AF admitted to the emergency departments in the Chinese AF Multicenter Registry study were enrolled. Basic demographics information, initial Blood Pressure and heart rate, medical histories, and treatments of each patient were collected. Follow-up was carried out with a mean duration of one year. The primary endpoint was all-cause mortality and systemic embolism.ResultsA total of 2016 patients were selected from September 2008 and April 2011. All-cause mortality was significantly higher in male AF patients with DM than those without (21.8 % & 13.6 %, P = 0.014). Cox regression analysis showed that there was an interaction between gender and DM for one-year all-cause mortality (P = 0.049). DM was significantly associated with one-year all-cause mortality regardless of univariate analysis (HR = 1.436, 95%CI:1.079–1.911, P = 0.013) or multivariate analysis (HR = 1.418, 95%CI: 1.059–1.899, P = 0.019). For male patients with AF, DM was significantly associated with one-year all-cause mortality (P = 0.048), but not for female patients with AF (P = 0.362).ConclusionDM was independently associated with one-year all-cause mortality in the entire cohort of AF patients. This association was found mainly in male patients with AF, but not in female patients. DM management programs may need to reflect gender difference.  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