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   2739158篇
  免费   204289篇
  国内免费   28098篇
耳鼻咽喉   36989篇
儿科学   80227篇
妇产科学   73215篇
基础医学   386443篇
口腔科学   75092篇
临床医学   265489篇
内科学   515550篇
皮肤病学   54882篇
神经病学   215869篇
特种医学   103804篇
外国民族医学   995篇
外科学   388425篇
综合类   102733篇
现状与发展   83篇
一般理论   887篇
预防医学   208613篇
眼科学   65325篇
药学   213567篇
  343篇
中国医学   22625篇
肿瘤学   160389篇
  2021年   32240篇
  2020年   22433篇
  2019年   28123篇
  2018年   36014篇
  2017年   29045篇
  2016年   30167篇
  2015年   38020篇
  2014年   50752篇
  2013年   66698篇
  2012年   91602篇
  2011年   98742篇
  2010年   58852篇
  2009年   52803篇
  2008年   85645篇
  2007年   90599篇
  2006年   91359篇
  2005年   88838篇
  2004年   80167篇
  2003年   76589篇
  2002年   73807篇
  2001年   116812篇
  2000年   121256篇
  1999年   104475篇
  1998年   31720篇
  1997年   29479篇
  1996年   27832篇
  1995年   26190篇
  1994年   24101篇
  1992年   78512篇
  1991年   76293篇
  1990年   74425篇
  1989年   71458篇
  1988年   66235篇
  1987年   64767篇
  1986年   61924篇
  1985年   58766篇
  1984年   43911篇
  1983年   37457篇
  1982年   22502篇
  1979年   41143篇
  1978年   29345篇
  1977年   24780篇
  1976年   23347篇
  1975年   25313篇
  1974年   30430篇
  1973年   29669篇
  1972年   28021篇
  1971年   26102篇
  1970年   24553篇
  1969年   23028篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. GWAS have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on chromosome 14q32.32 alter splicing and expression of PAR-1a/microtubule affinity regulating kinase 3 (MARK3), a conserved serine/threonine kinase known to regulate bioenergetics, cell division, and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3-deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3-deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3-deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass.  相似文献   
22.
23.
The coronavirus disease 2019 (COVID-19) pandemic has rapidly created widespread impacts on global health and the economy. Data suggest that women are less susceptible to severe illness. However, sex-disaggregated data are incomplete, leaving room for misinterpretation, and focusing only on biologic sex underestimates the gendered impact of the pandemic on women. This narrative review summarizes what is known about gender disparities during the COVID-19 pandemic and the economic, domestic, and health burdens along with overlapping vulnerabilities related to the pandemic. In addition, this review outlines recommended strategies that advocacy groups, community leaders, and policymakers should implement to mitigate the widening gender disparities related to COVID-19.  相似文献   
24.
25.
26.
The coronavirus 2019 pandemic has affected almost every aspect of health care delivery in the United States, and the emergency medicine system has been hit particularly hard while dealing with this public health crisis. In an unprecedented time in our history, medical systems and clinicians have been asked to be creative, flexible, and innovative, all while continuing to uphold the important standards in the US health care system. To continue providing quality services to patients during this extraordinary time, care providers, organizations, administrators, and insurers have needed to alter longstanding models and procedures to respond to the dynamics of a pandemic. The Emergency Medicine Treatment and Active Labor Act of 1986, or EMTALA, is 1 example of where these alterations have allowed health care facilities and clinicians to continue their work of caring for patients while protecting both the patients and the clinicians themselves from infectious exposures at the same time.  相似文献   
27.
28.
Lessons Learned
  • SCB01A is a novel microtubule inhibitor with vascular disrupting activity.
  • This first‐in‐human study demonstrated SCB01A safety, pharmacokinetics, and preliminary antitumor activity.
  • SCB01A is safe and well tolerated in patients with advanced solid malignancies with manageable neurotoxicity.
BackgroundSCB01A, a novel microtubule inhibitor, has vascular disrupting activity.MethodsIn this phase I dose‐escalation and extension study, patients with advanced solid tumors were administered intravenous SCB01A infusions for 3 hours once every 21 days. Rapid titration and a 3 + 3 design escalated the dose from 2 mg/m2 to the maximum tolerated dose (MTD) based on dose‐limiting toxicity (DLT). SCB01A‐induced cellular neurotoxicity was evaluated in dorsal root ganglion cells. The primary endpoint was MTD. Safety, pharmacokinetics (PK), and tumor response were secondary endpoints.ResultsTreatment‐related adverse events included anemia, nausea, vomiting, fatigue, fever, and peripheral sensorimotor neuropathy. DLTs included grade 4 elevated creatine phosphokinase (CPK) in the 4 mg/m2 cohort; grade 3 gastric hemorrhage in the 6.5 mg/m2 cohort; grade 2 thromboembolic event in the 24 mg/m2 cohort; and grade 3 peripheral sensorimotor neuropathy, grade 3 elevated aspartate aminotransferase, and grade 3 hypertension in the 32 mg/m2 cohort. The MTD was 24 mg/m2, and average half‐life was ~2.5 hours. The area under the curve‐dose response relationship was linear. Nineteen subjects were stable after two cycles. The longest treatment lasted 24 cycles. SCB01A‐induced neurotoxicity was reversible in vitro.ConclusionThe MTD of SCB01A was 24 mg/m2 every 21 days; it is safe and tolerable in patients with solid tumors.  相似文献   
29.
30.
BackgroundTotal hip and knee arthroplasties are increasingly performed operations, and routine follow-up places huge demands on orthopedic services. This study investigates the effectiveness, patients’ satisfaction, and cost reduction of Virtual Joint Replacement Clinic (VJRC) follow-up of total hip arthroplasty and total knee arthroplasty patients in a university hospital. VJRC is especially valuable when in-person appointments are not advised or feasible such as during the COVID-19 pandemic.MethodsA total of 1749 patients who were invited for VJRC follow-up for knee or hip arthroplasty from January 2017 to December 2018 were included in this retrospective study. Patients were referred to VJRC after their 6-week postoperative review. Routine VJRC postoperative review was undertaken at 1 and 7 years and then 3-yearly thereafter. We evaluated the VJRC patient response rate, acceptability, and outcome. Patient satisfaction was measured in a subgroup of patients using a satisfaction survey. VJRC costs were calculated compared to face-to-face follow-up.ResultsThe VJRC had a 92.05% overall response rate. Only 7.22% required further in-person appointments with only 3% being reviewed by an orthopedic consultant. VJRC resulted in an estimated saving of £42,644 per year at our institution. The patients’ satisfaction survey showed that 89.29% of the patients were either satisfied or very satisfied with VJRC follow-up.ConclusionVJRC follow-up for hip and knee arthroplasty patients is an effective alternative to in-person clinic assessment which is accepted by patients, has high patient satisfaction, and can reduce the cost to both health services and patients.  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