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   1052280篇
  免费   83785篇
  国内免费   25976篇
耳鼻咽喉   11917篇
儿科学   27955篇
妇产科学   21676篇
基础医学   146465篇
口腔科学   25816篇
临床医学   112606篇
内科学   178526篇
皮肤病学   19990篇
神经病学   66207篇
特种医学   39096篇
外国民族医学   299篇
外科学   135023篇
综合类   83497篇
一般理论   190篇
预防医学   76504篇
眼科学   26617篇
药学   93157篇
  337篇
中国医学   26379篇
肿瘤学   69784篇
  2022年   9676篇
  2021年   19613篇
  2020年   17493篇
  2019年   16314篇
  2018年   18416篇
  2017年   17325篇
  2016年   15716篇
  2015年   23081篇
  2014年   30590篇
  2013年   33711篇
  2012年   47874篇
  2011年   52231篇
  2010年   34001篇
  2009年   29169篇
  2008年   41051篇
  2007年   42329篇
  2006年   41737篇
  2005年   39422篇
  2004年   32447篇
  2003年   30980篇
  2002年   28242篇
  2001年   44467篇
  2000年   44848篇
  1999年   38310篇
  1998年   12639篇
  1997年   11267篇
  1996年   10408篇
  1995年   10273篇
  1994年   9167篇
  1993年   7556篇
  1992年   25270篇
  1991年   24956篇
  1990年   24044篇
  1989年   23561篇
  1988年   21247篇
  1987年   20495篇
  1986年   19350篇
  1985年   17938篇
  1984年   13024篇
  1983年   10967篇
  1979年   11635篇
  1978年   8184篇
  1977年   6863篇
  1976年   6614篇
  1975年   7283篇
  1974年   8531篇
  1973年   8166篇
  1972年   7685篇
  1971年   7144篇
  1970年   6893篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Modified-release opioids are often prescribed for the management of moderate to severe acute pain following total hip and knee arthroplasty, despite recommendations against their use due to increasing concerns regarding harm. The primary objective of this multicentre study was to examine the impact of modified-release opioid use on the incidence of opioid-related adverse events compared with immediate-release opioid use, among adult inpatients following total hip or knee arthroplasty. Data for total hip and knee arthroplasty inpatients receiving an opioid analgesic for postoperative analgesia during hospitalisation were collected from electronic medical records of three tertiary metropolitan hospitals in Australia. The primary outcome was the incidence of opioid-related adverse events during hospital admission. Patients who received modified with or without immediate-release opioids were matched to those receiving immediate-release opioids only (1:1) using nearest neighbour propensity score matching with patient and clinical characteristics as covariates. This included total opioid dose received. In the matched cohorts, patients given modified-release opioids (n = 347) experienced a higher incidence of opioid-related adverse events overall, compared with those given immediate-release opioids only (20.5%, 71/347 vs. 12.7%, 44/347; difference in proportions 7.8% [95%CI 2.3–13.3%]). Modified-release opioid use was associated with an increased risk of harm when used for acute pain during hospitalisation after total hip or knee arthroplasty.  相似文献   
3.
4.
目的 探讨集束化干预策略联合闭环管理模式对ICU多重耐药菌感染的防控效果。方法选取2020年1~12月EICU住院患者275例作为对照组,实施常规管理;2021年1~10月EICU住院患者239例作为观察组,在常规管理基础上实施集束化干预策略联合闭环管理。结果实施后,观察组多重耐药菌感染发生率明显低于对照组;患者住院日显著低于对照组,4项护理措施执行率(隔离标识、手卫生、环境消毒、医务人员相关知识知晓)、病原学送检率显著高于对照组(均P<0.05)。结论集束化干预联合信息化闭环管理可有效降低EICU多重耐药菌感染发生率。  相似文献   
5.
Huo  Jia  Fu  Lijun  Jin  Mengyuan  Li  Zhaoming  Zhang  Mingzhi 《Investigational new drugs》2022,40(3):537-545
Investigational New Drugs - Background&nbsp;Chemotherapy resistance is a main reason for treatment failure in extranodal NK/T-cell lymphoma (ENKTL). Interleukin-10 (IL-10) is closely related to...  相似文献   
6.
Pharmaceutical Chemistry Journal - Cyclin-dependent kinases 4 and 6 (CDK4/6) are the core part of the cell cycle control machinery, which bind to cyclin D to regulate cell G1-S cycle conversion....  相似文献   
7.
In the last decade, the development of new radiopharmaceuticals for the imaging and therapy of prostate cancer has been a highly active and important area of research, especially focusing on the prostate-specific membrane antigen (PSMA), an antigen which is upregulated in prostate, as well as in other tumor cells. A large variety of PSMA ligands have been radiolabeled, to date. Among the various derivatives, PSMA-617 resulted to be one of the most interesting in terms of interaction with the antigen and clinical properties, and its lutetium-177 labeled version has recently been approved by regulatory agencies for therapeutic purposes. For this reasons, the radiolabeling with fluorine-18 of a PSMA-617 derivative might be of interest. Beside other methodologies to radiolabel macromolecules with fluorine-18, the “click-chemistry” approach resulted to be very useful, and the copper-catalyzed azide-alkyne cycloaddition (CuAAC) is considered one of most efficient and reliable. This paper proposes the synthesis of a suitable precursor for the radiolabeling with fluorine-18 of a new PSMA-617 derivative. The whole radiosynthetic procedure has been fully automated, and the final product, which proved to be stable in plasma, has been obtained with radiochemical yield and purity suitable for subsequent preclinical studies.  相似文献   
8.
9.
10.
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes.  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