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   251249篇
  免费   21607篇
  国内免费   7901篇
耳鼻咽喉   1648篇
儿科学   4560篇
妇产科学   2772篇
基础医学   28814篇
口腔科学   3798篇
临床医学   21574篇
内科学   29957篇
皮肤病学   2830篇
神经病学   9772篇
特种医学   5142篇
外国民族医学   28篇
外科学   20495篇
综合类   49015篇
现状与发展   18篇
一般理论   34篇
预防医学   20623篇
眼科学   4873篇
药学   24574篇
  143篇
中国医学   33372篇
肿瘤学   16715篇
  2024年   611篇
  2023年   3376篇
  2022年   5809篇
  2021年   9565篇
  2020年   8606篇
  2019年   9688篇
  2018年   8884篇
  2017年   8681篇
  2016年   8158篇
  2015年   8101篇
  2014年   15358篇
  2013年   15114篇
  2012年   14894篇
  2011年   16277篇
  2010年   13880篇
  2009年   12522篇
  2008年   11628篇
  2007年   12856篇
  2006年   11345篇
  2005年   10566篇
  2004年   9012篇
  2003年   7931篇
  2002年   5913篇
  2001年   5695篇
  2000年   4669篇
  1999年   4152篇
  1998年   2936篇
  1997年   2655篇
  1996年   2633篇
  1995年   2472篇
  1994年   2172篇
  1993年   1868篇
  1992年   1605篇
  1991年   1422篇
  1990年   1149篇
  1989年   1080篇
  1988年   1015篇
  1987年   792篇
  1986年   594篇
  1985年   1494篇
  1984年   2014篇
  1983年   1476篇
  1982年   1575篇
  1981年   1502篇
  1980年   1299篇
  1979年   1143篇
  1978年   907篇
  1977年   663篇
  1976年   860篇
  1975年   701篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
中西医结合治疗动眼神经麻痹疗效观察   总被引:2,自引:0,他引:2  
目的了解中西医结合法治疗动眼神经麻痹的临床疗效。方法对我院2012-03—2014-03收治的动眼神经麻痹患者进行抽样,择取74例患者随机分成2组,对照组予以基础性西医疗法,实验组在对照组治疗基础上予以中医疗法(包括针刺及服用中药正容汤等),观察2组患者的临床治疗效果。结果实验组总有效率(94.60%)明显高于对照组(64.86%),差异具有统计学意义(P0.05)。结论中西医结合法治疗动眼神经麻痹临床疗效确切,安全系数高,值得临床大力推广使用。  相似文献   
82.
The retroviral protease of human immunodeficiency virus (HIV) is an excellent target for antiviral inhibitors for treating HIV/AIDS. Despite the efficacy of therapy, current efforts to control the disease are undermined by the growing threat posed by drug resistance. This review covers the historical background of studies on the structure and function of HIV protease, the subsequent development of antiviral inhibitors, and recent studies on drug-resistant protease variants. We highlight the important contributions of Dr. Stephen Oroszlan to fundamental knowledge about the function of the HIV protease and other retroviral proteases. These studies, along with those of his colleagues, laid the foundations for the design of clinical inhibitors of HIV protease. The drug-resistant protease variants also provide an excellent model for investigating the molecular mechanisms and evolution of resistance.  相似文献   
83.
Purpose: Mouse double-stranded DNA-dependent protein kinase (DNA-PK) activity is heat sensitive. Recovery of heat-inactivated DNA repair activity is a problem after combination therapy with radiation and heat. We investigated the mechanism of recovery of heat-inactivated DNA-PK activity.

Methods: Hybrid cells containing a fragment of human chromosome 8 in scid cells (RD13B2) were used. DNA-PK activity was measured by an in vitro assay. Immunoprecipitation of the nuclear extract was performed with an anti-Ku80 antibody. Proteins co-precipitated with Ku80 were separated by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis and detected by Western blotting using anti-heat shock protein (HSP)72 and anti-heat shock cognate protein (HSC)73 antibodies. HSC73 was overexpressed with the pcDNA3.1 vector. Short hairpin (sh)RNA was used to downregulate HSC73 and HSP72.

Results: The activity of heat-inactivated DNA-PK recovered to about 50% of control during an additional incubation at 37?°C after heat treatment at 44?°C for 15?min in the presence of cycloheximide (which inhibits de novo protein synthesis). Maximal recovery was observed within 3?h of incubation at 37?°C after heat treatment. Constitutively expressed HSC73, which folds newly synthesized proteins, reached maximal levels 3?h after heat treatment using a co-immunoprecipitation assay with the Ku80 protein. Inhibiting HSC73, but not HSP72, expression with shRNA decreased the recovery of DNA-PK activity after heat treatment.

Conclusions: These results suggest that de novo protein synthesis is unnecessary for recovery of some heat-inactivated DNA-PK. Rather, it might be reactivated by the molecular chaperone activity of HSC73, but not HSP72.  相似文献   

84.
目的 通过对公开发表在网络和数据库的有关中医药治疗2019新型冠状病毒肺炎(corona virus disease 2019,COVID-19)的文献进行方、药、证的可视化分析,客观全面的对COVID-19的中医药治疗进行探讨,为现代中医临床诊疗提供参考。方法 本文选用运用文献计量学方法和VOSviewer可视化软件对纳入文献中的用药情况进行数据拆分、整理和分析。结果 本研究高质量数据的主要期刊来源是核心期刊《中医杂志》;新冠临床用方以解表清热剂、开窍补益剂、辟秽祛湿剂为主;临床用药以解表药、清热解毒药、化湿祛痰药以及补益药为主;临床治病思路以六经辨证、三焦辨证和卫气营血辨证理论为指导;临床常见证型为湿、热、寒、毒相关证型;重视新冠前期预防以及后期恢复调养;治疗过程用药考究,注重养阴与祛邪并进。结论 新冠的中医临床诊治考病全面,并注重养阴与祛邪并进,可为官方制定治疗方案提供参考。  相似文献   
85.
To provide policy recommendations for managing Coronavirus 19 (COVID-19) in skilled nursing facilities, a group of certified medical directors from several facilities in New York state with experience managing the disease used e-mail, phone, and video conferencing to develop consensus recommendations. The resulting document provides recommendations on screening, protection of staff, screening of residents, management of Coronavirus 19 positive and presumed positive cases, communication during an outbreak, management of admissions and readmissions, and providing emotional support for staff. These consensus guidelines have been endorsed by the Executive Board of the New York Medical Directors Association and the Board of the Metropolitan Area Geriatrics Society.  相似文献   
86.
目的:探讨老年人桡骨远端C型骨折的手术治疗与非手术治疗的疗效差异,评价两种方法的优缺点。方法回顾性分析2009-12—2011-12收治的老年桡骨远端C型骨折68例,按照治疗方法分为A组(手术组)及B组(非手术组),统计分析两组患者的临床资料。结果 A组33例, B组35例,平均随访21.5个月。两组患者的年龄、骨折类型均无差异(P>0.05);术后影像学指标A组优于B组,骨折愈合时间B组优于A组,治疗成本A组大于B组(P<0.05);Cooney评分早期A组优于B组,1年后两组无差异,两组的并发症无差异(P>0.05)。结论老年人桡骨远端C型骨折手术治疗较非手术治疗可获得更好的复位及早期功能,但远期功能恢复无差异。  相似文献   
87.
高强度聚焦超声(high-intensity focused ultrasound,HIFU)消融治疗子宫肌瘤作为一种新的非侵入性的治疗方式,已越来越广泛地用于子宫肌瘤的治疗。但是对于HIFU治疗时妊娠的处理及妊娠结局鲜有文献报道。本文报道1例HIFU消融治疗子宫肌瘤时妊娠的病例,结合文献复习,探讨子宫平滑肌瘤对妊娠的影响、子宫平滑肌瘤不同处理方式对妊娠的影响、HIFU消融治疗子宫肌瘤时机选择的问题、HIFU消融治疗子宫肌瘤若同时合并妊娠时胎儿去留的问题以及近期HIFU消融治疗子宫肌瘤后对流产手术操作的影响等,以期对HIFU治疗子宫肌瘤的适应证、选择合适的治疗时间及术后选择合适的妊娠时机展开讨论。  相似文献   
88.
The chemical composition, structure and surface characteristics of biomaterials/scaffold can affect the adsorption of proteins, and this in turn influences the subsequent cellular response and tissue regeneration. With magnesium/calcium phosphate cements (MCPC) as model, the effects of magnesium (Mg) on the initial adhesion and osteogenic differentiation of bone marrow stromal cells (BMSCs) as well as the underlying mechanism were investigated. A series of MCPCs with different magnesium phosphate cement (MPC) content (0∼20%) in calcium phosphate cement (CPC) were synthesized. MCPCs with moderate proportion of MPC (5% and 10%, referred to as 5MCPC and 10MCPC) were found to effectively modulate the orientation of the adsorbed fibronectin (Fn) to exhibit enhanced receptor binding affinity, and to up-regulate integrin α5β1 expression of BMSCs, especially for 5MCPC. As a result, the attachment, morphology, focal adhesion formation, actin filaments assembly and osteogenic differentiation of BMSCs on 5MCPC were strongly enhanced. Further in vivo experiments confirmed that 5MCPC induced promoted osteogenesis in comparison to ot her CPC/MCPCs. Our results also suggested that the Mg on the underlying substrates but not the dissolved Mg ions was the main contributor to the above positive effects. Based on these results, it can be inferred that the specific interaction of Fn and integrin α5β1 had predominant effect on the MCPC-induced enhanced cellular response of BMSCs. These results provide a new strategy to regulate BMSCs adhesion and osteogenic differentiation by adjusting the Mg/Ca content and distribution in CPC, guiding the development of osteoinductive scaffolds for bone tissue regeneration.  相似文献   
89.
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic.  相似文献   
90.
PurposeThis study describes the job market from the perspective of recent pediatric surgery graduates.MethodsAn anonymous survey was circulated to the 137 pediatric surgeons who graduated from fellowships 2019–2021.ResultsThe survey response rate was 49%. The majority of respondents were women (52%), Caucasian (72%), and had a median student debt burden of $225,000. Considering job opportunities, respondents strongly emphasized camaraderie (93%), mentorship (93%), case mix (85%), geography (67%), faculty reputation (62%), spousal employment (57%), compensation (51%), and call frequency (45%). 30% were satisfied with the employment opportunities available, and 21% felt strongly prepared to negotiate for their first job. All respondents were able to secure a job. Most jobs were university-based (70%) or hospital employed (18%) positions where surgeons covered median of two hospitals. 49% wanted protected research time, and 12% of respondents were able to secure substantial, protected research time. The median compensation for university-based jobs was $12,583 below the median AAMC benchmark for assistant professors for the corresponding year of graduation.ConclusionThese data highlight the ongoing need for assessment of the pediatric surgery workforce and for professional societies and training programs to further assist graduating fellows in preparing to negotiate their first job.Type of studySurveyLevel of EvidenceLevel V.  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