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   219716篇
  免费   12082篇
  国内免费   6434篇
耳鼻咽喉   2749篇
儿科学   8258篇
妇产科学   2983篇
基础医学   16777篇
口腔科学   4173篇
临床医学   26710篇
内科学   39703篇
皮肤病学   3023篇
神经病学   10841篇
特种医学   12144篇
外国民族医学   22篇
外科学   32872篇
综合类   19477篇
现状与发展   25篇
预防医学   14653篇
眼科学   4403篇
药学   23818篇
  80篇
中国医学   4488篇
肿瘤学   11033篇
  2023年   1873篇
  2022年   3656篇
  2021年   8885篇
  2020年   5158篇
  2019年   11088篇
  2018年   5708篇
  2017年   4891篇
  2016年   6889篇
  2015年   9729篇
  2014年   17789篇
  2013年   15509篇
  2012年   18825篇
  2011年   15603篇
  2010年   14399篇
  2009年   14015篇
  2008年   12593篇
  2007年   12671篇
  2006年   10666篇
  2005年   7009篇
  2004年   3484篇
  2003年   3057篇
  2002年   2476篇
  2001年   1951篇
  2000年   1770篇
  1999年   1094篇
  1998年   1485篇
  1997年   1355篇
  1996年   1143篇
  1995年   1216篇
  1994年   1174篇
  1993年   913篇
  1992年   1127篇
  1991年   1028篇
  1990年   1052篇
  1989年   1029篇
  1988年   949篇
  1987年   833篇
  1986年   678篇
  1985年   1594篇
  1984年   1748篇
  1983年   1259篇
  1982年   1349篇
  1981年   1333篇
  1980年   1151篇
  1979年   987篇
  1978年   763篇
  1977年   759篇
  1976年   662篇
  1975年   437篇
  1974年   457篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Anthrax is a zoonotic infection caused by the gram-positive, aerobic, spore-forming bacterium Bacillus anthracis. Depending on the origin of the infection, serious health problems or mortality is possible. The virulence of B. anthracis is reliant on three pathogenic factors, which are secreted upon infection: protective antigen (PA), lethal factor (LF), and edema factor (EF). Systemic illness results from LF and EF entering cells through the formation of a complex with the heptameric form of PA, bound to the membrane of infected cells through its receptor. The currently available anthrax vaccines have multiple drawbacks, and recombinant PA is considered a promising second-generation vaccine candidate. However, the inherent chemical instability of PA through Asn deamidation at multiple sites prevents its use after long-term storage owing to loss of potency. Moreover, there is a distinct possibility of B. anthracis being used as a bioweapon; thus, the developed vaccine should remain efficacious and stable over the long-term. Second-generation anthrax vaccines with appropriate adjuvant formulations for enhanced immunogenicity and safety are desired. In this article, using protein engineering approaches, we have reviewed the stabilization of anthrax vaccine candidates that are currently licensed or under preclinical and clinical trials. We have also proposed a formulation to enhance recombinant PA vaccine potency via adjuvant formulation.  相似文献   
72.
目的:分析比较"F"形空心钉与传统倒三角3枚平行螺钉内固定治疗青壮年Pauwels Ⅲ型股骨颈骨折的临床疗效。方法:2017年1月至2020年1月收治Pauwels Ⅲ型股骨颈骨折患者38例,根据置入钉方式的不同将其分为两组,其中A组18例,采用"F"形空心钉固定,男12例,女6例,年龄37~55岁,受伤至手术时间1~3 d。B组20例,采用传统倒三角3枚平行拉力螺钉固定,男12例,女8例,年龄35~55岁,受伤至手术时间为1~3 d。比较两组患者骨折不愈合,股骨头坏死,股骨颈短缩,空心螺钉退出情况,髋关节功能Harris评分,疼痛视觉模拟评分(visual analogue scale,VAS)。结果:所有患者获得随访,时间为15~31个月。两组患者在骨折不愈合,股骨颈短缩,股骨头坏死方面差异无统计学意义(P>0.05);两组患者在螺钉退出方面差异有统计学意义(P<0.05)。两组患者术后12个月时髋关节Harris评分及VAS评分差异均无统计学差异(P>0.05)。结论:"F"形与传统倒三角3枚平行空心钉内固定治疗青壮年Pauwels Ⅲ型股骨颈骨折中短期疗效相似,但"F"形空心钉退钉率较低。  相似文献   
73.
74.
This article begins with an overview of the knowledge translation (KT) process, introduces commonly used KT terms and the Aware-Adopt-Adapt (A3) KT map. The A3 was created by a nurse practitioner (NP) for practitioners and NP students to provide a map for those who wish to move existing knowledge to practice, yet do not know where to start or do not have the time to take a deeper dive into specific KT theories.  相似文献   
75.
76.
《Survey of ophthalmology》2022,67(6):1647-1684
Managing pediatric corneal disorders is challenging as the prognosis of pediatric keratoplasty depends on several factors. Advancements in the genetic basis of congenital corneal diseases and investigations in congenital corneal conditions provide a better understanding of pediatric corneal conditions. Surgeons performing keratoplasty in children now have a choice of various techniques. Evolving surgical techniques of anterior lamellar and endothelial keratoplasties have expanded the management interventions in these pediatric corneal morbidity conditions; however, considerable concerns still exist in association with corneal transplantation in infants and children. Outcomes in pediatric keratoplasty depend upon the preoperative indications, the timing of surgical intervention, intraoperative and postoperative factors including the patient/care givers’ compliance. Factors such as low scleral rigidity, higher rate of graft failure, need for frequent examinations under anesthesia, and difficulty in optimal visual acuity assessment still remain a considerable challenge in pediatric scenarios. In children, deprivation amblyopia as a result of the corneal opacification can adversely affect visual development, causing dense amblyopia. Outcomes to surgical interventions for management of corneal opacification in children are further compromised by the preexisting amblyopia apart from the concerns of refractive outcome of the graft. Graft rejection, graft infection, amblyopia, and glaucoma continue to be serious concerns. In recent years both anterior and posterior lamellar keratoplasty techniques are being increasingly performed in pediatric eyes, which offer advantages in the form of lower risk of graft rejection. The timing of surgery, careful case selection, cautious intraoperative approach, and optimal postoperative management can improve the anatomical and functional outcome in difficult cases.  相似文献   
77.
IntroductionEndoscopic surveillance guidelines for patients with repaired esophageal atresia (EA) rely primarily on expert opinion. Prior to embarking on a prospective EA surveillance registry, we sought to understand EA surveillance practices within the Eastern Pediatric Surgery Network (EPSN).MethodsAn anonymous, 23-question Qualtrics survey was emailed to 181 physicians (surgeons and gastroenterologists) at 19 member institutions. Likert scale questions gauged agreement with international EA surveillance guideline-derived statements. Multiple-choice questions assessed individual and institutional practices.ResultsThe response rate was 77%. Most respondents (80%) strongly agree or agree that EA surveillance endoscopy should follow a set schedule, while only 36% claimed to perform routine upper GI endoscopy regardless of symptoms. Many institutions (77%) have an aerodigestive clinic, even if some lack a multi-disciplinary EA team. Most physicians (72%) expressed strong interest in helping develop evidence-based guidelines.ConclusionsOur survey reveals physician agreement with current guidelines but weak adherence. Surveillance methods vary greatly, underscoring the lack of evidence-based data to guide EA care. Aerodigestive clinics may help implement surveillance schedules. Respondents support evidence-based protocols, which bodes well for care standardization. Results will inform the first multi-institutional EA databases in the United States (US), which will be essential for evidence-based care.Level of EvidenceThis is a prognosis study with level 4 evidence.  相似文献   
78.
目的探讨解偶联蛋白1(UCP1)基因多态性与2型糖尿病(T2DM)心脑血管并发症的相关性。方法选取2019年7月—2020年7月住院治疗的T2DM 440例,根据有无心脑血管并发症分为观察组(T2DM合并心脑血管并发症)221例和对照组(单纯T2DM)219例。比较两组一般资料,UCP1在rs45539933、rs10011540及rs1800592位点的基因型分布与等位基因频率;通过多因素Logistic回归分析评估T2DM发生心脑血管事件的危险因素。结果观察组病程长于对照组,糖化血红蛋白水平高于对照组,而血清高密度脂蛋白胆固醇水平低于对照组(P<0.01)。观察组C/C基因型分布及C碱基频率均高于对照组(P<0.05)。C/C基因型是T2DM患者发生心脑血管并发症的危险因素(P<0.05)。结论UCP1基因多态性与T2DM心脑血管并发症的发生显著相关。  相似文献   
79.
80.
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