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   6772篇
  免费   310篇
  国内免费   39篇
耳鼻咽喉   131篇
儿科学   649篇
妇产科学   103篇
基础医学   765篇
口腔科学   156篇
临床医学   500篇
内科学   1166篇
皮肤病学   121篇
神经病学   349篇
特种医学   225篇
外科学   923篇
综合类   182篇
一般理论   2篇
预防医学   491篇
眼科学   253篇
药学   553篇
中国医学   33篇
肿瘤学   519篇
  2022年   106篇
  2021年   184篇
  2020年   118篇
  2019年   159篇
  2018年   139篇
  2017年   112篇
  2016年   175篇
  2015年   157篇
  2014年   268篇
  2013年   305篇
  2012年   427篇
  2011年   421篇
  2010年   306篇
  2009年   213篇
  2008年   326篇
  2007年   343篇
  2006年   352篇
  2005年   319篇
  2004年   241篇
  2003年   239篇
  2002年   183篇
  2001年   99篇
  2000年   76篇
  1999年   91篇
  1998年   86篇
  1997年   61篇
  1996年   53篇
  1995年   46篇
  1993年   36篇
  1992年   66篇
  1991年   69篇
  1990年   46篇
  1989年   77篇
  1988年   51篇
  1987年   61篇
  1986年   65篇
  1985年   60篇
  1984年   42篇
  1982年   40篇
  1981年   44篇
  1980年   45篇
  1979年   55篇
  1978年   38篇
  1977年   38篇
  1976年   43篇
  1975年   53篇
  1974年   61篇
  1973年   42篇
  1971年   46篇
  1970年   47篇
排序方式: 共有7121条查询结果,搜索用时 0 毫秒
41.
Candida biofilm resistance.   总被引:2,自引:0,他引:2  
Device-related infections in most nosocomial diseases can be traced to the formation of biofilms (microbial communities encased within polysaccharide-rich extracellular matrix) by pathogens on surfaces of these devices. Candida species are the most common fungi isolated from these infections, and biofilms formed by these fungal organisms are associated with drastically enhanced resistance against most antimicrobial agents. This enhanced resistance contributes to the persistence of this fungus despite antifungal therapy. Candida biofilms exhibit enhanced resistance against most antifungal agents, except echinocandins and lipid formulations of AmB. The expression of drug efflux pumps during the early phase of biofilm formation and alterations in membrane sterol composition contribute to resistance of these biofilms against azoles. Metabolic dormancy and ECM do not appear to contribute to resistance, although in a mixed-species biofilm, ECM does retard the diffusion of drugs across biofilm. These multifactorial mechanisms of resistance in fungal biofilms constitute a broad-spectrum defense that is effective against many types of antifungal agents, and represent a common theme present across microbial biofilms.  相似文献   
42.
43.
Lateral Ankle sprain is a common sports-related trauma with the mechanism of injury ranging from inversion to plantar flexion. These injuries commonly affect the ligaments but can also affect the associated soft tissue structures like the eversion muscles and tendons. Prompt and accurate diagnosis of such injuries is warranted so as to ensure early return to play and prevent long-term complications. Lateral ankle sprain injuries in sports may not always be associated with ligament injuries. We report a never before reported case of lateral ankle sprain injury in a soccer player with the unusual finding of isolated partial tear of Extensor digitorum longus muscle and its fascia leading to myo-fascial herniation. The lateral ankle ligaments were intact. The diagnosis was clinched on a high-frequency ultrasound scan supported by dynamic maneuvers which in fact proved to be superior to MRI as the latter failed to demonstrate the myo-fascial herniation in our case. We therefore propose that real-time ultrasound scanning with dynamic maneuvers should be the first line of investigation to assess sports injuries in anatomically complex joints like the ankle.  相似文献   
44.
We describe a patient who presented with fatigue and pulling sensation in his lower limbs. He had continuous muscle contractions over his trunk (myokymia) which pointed towards the diagnosis of Isaacs syndrome which was confirmed by strongly positive CASPR2 antibodies in blood.  相似文献   
45.
46.
Cancer therapy is a fast-emerging biomedical paradigm that elevates the diagnostic and therapeutic potential of a nanovector for identification, monitoring, targeting, and post-treatment response analysis. Nanovectors of superparamagnetic iron oxide nanoparticles (SPION) are of tremendous significance in cancer therapy because of their inherited high surface area, high reactivity, biocompatibility, superior contrast, and magnetic and photo-inducibility properties. In addition to a brief introduction, we summarize various progressive aspects of nanomagnets pertaining to their production with an emphasis on sustainable biomimetic approaches. Post-synthesis particulate and surface alterations in terms of pharmaco-affinity, liquid accessibility, and biocompatibility to facilitate cancer therapy are highlighted. SPION parameters including particle contrast, core-fusions, surface area, reactivity, photosensitivity, photodynamics, and photothermal properties, which facilitate diverse cancer diagnostics, are discussed. We also elaborate on the concept of magnetism to selectively focus chemotherapeutics on tumors, cell sorting, purification of bioentities, and elimination of toxins. Finally, while addressing the toxicity of nanomaterials, the advent of ultrasmall nanomagnets as a healthier alternative with superior properties and compatible cellular interactions is reviewed. In summary, these discussions spotlight the versatility and integration of multi-tasking nanomagnets and ultrasmall nanomagnets for diverse cancer theragnostics.  相似文献   
47.
48.
49.
Hypovitaminosis D is prevalent worldwide, and especially in South-Asia. According to the Institute of Medicine (IOM), 25(OH)D levels below 30 nmol/L are defined as vitamin D deficiency (VDD) and levels between 30–50 nmol/L as insufficiency (VDI). Besides its role in calcium homeostasis, it has been postulated that vitamin D is involved in metabolic syndrome. Given the scarcity of data on vitamin D status in Nepal, we aimed to examine the prevalence of VDD and VDI, as well as the determinants and association with metabolic parameters (lipids, HbA1c), in a cohort of women in rural Nepal. Altogether, 733 women 48.5 ± 11.7 years of age were included. VDD and VDI were observed in 6.3 and 42.4% of the participants, respectively, and the prevalence increased by age. Women reporting intake of milk and eggs > 2 times weekly had higher 25(OH)D levels than those reporting intake < 2 times weekly. Women with vitamin D levels < 50 nmol/L displayed higher levels of cholesterol, LDL-cholesterol, triglycerides, and HbA1c. Additionally, a regression analysis showed a significant association between hypovitaminosis D, dyslipidemia, and HbA1c elevation. In conclusion, VDI was prevalent and increased with age. Milk and egg intake > 2 times weekly seemed to decrease the risk of VDI. Moreover, hypovitaminosis D was associated with an adverse metabolic profile.  相似文献   
50.
The effect of GABA antagonists picrotoxin and bicuculline was studied on hyperphagia caused by 2-DG and 5-TG. The GABA antagonists were administered either SC or into the VMH or LH through stereotaxically implanted chronic cannulae. The peripheral as well as VMH injection antagonised the hyperphagia significantly. In contrast, injection of these agents into the LH failed to produce any effect. These findings show that in a glucoprivic state there might be an increased GABAergic activity in the VMH.  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