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   5067篇
  免费   387篇
  国内免费   15篇
耳鼻咽喉   102篇
儿科学   234篇
妇产科学   134篇
基础医学   628篇
口腔科学   149篇
临床医学   384篇
内科学   1223篇
皮肤病学   68篇
神经病学   399篇
特种医学   409篇
外科学   767篇
综合类   34篇
一般理论   5篇
预防医学   330篇
眼科学   126篇
药学   237篇
中国医学   23篇
肿瘤学   217篇
  2023年   25篇
  2022年   66篇
  2021年   146篇
  2020年   78篇
  2019年   130篇
  2018年   156篇
  2017年   107篇
  2016年   106篇
  2015年   109篇
  2014年   161篇
  2013年   181篇
  2012年   309篇
  2011年   332篇
  2010年   182篇
  2009年   148篇
  2008年   282篇
  2007年   261篇
  2006年   252篇
  2005年   222篇
  2004年   228篇
  2003年   199篇
  2002年   210篇
  2001年   171篇
  2000年   201篇
  1999年   131篇
  1998年   40篇
  1997年   44篇
  1996年   49篇
  1995年   56篇
  1994年   40篇
  1993年   26篇
  1992年   85篇
  1991年   85篇
  1990年   80篇
  1989年   70篇
  1988年   60篇
  1987年   41篇
  1986年   46篇
  1985年   37篇
  1984年   25篇
  1983年   18篇
  1982年   14篇
  1979年   16篇
  1974年   20篇
  1973年   24篇
  1972年   20篇
  1971年   21篇
  1970年   19篇
  1968年   16篇
  1967年   18篇
排序方式: 共有5469条查询结果,搜索用时 390 毫秒
91.
92.
It is well accepted that the presence of cytokines belonging to the Th1/Th17/Th22 axis of immuno‐inflammatory response in the joint environment, such as IL‐1β, IL‐17 and IL‐22, respectively, are associated with pathogenesis of several synovial joint degenerative disorders. During temporomandibular joint osteoarthritis (TMJ‐OA), IL‐1β and IL‐17 have been implicated in the inflammation and resorption of sub‐chondral bone; however, the role of Th22 response in the TMJ‐OA pathophysiology has not been established. This study aimed to compare the expression of Th1/Th17/Th22‐type cytokines, chemokines and chemokine receptors in synovial fluid samples obtained from TMJ‐OA or disk displacement with reduction (DDWR) patients. In addition, it aimed to associate these levels with joint pain, imagenological signs of bone degeneration, RANKL production, osteoclastogenesis and osteoclast‐induced bone resorption. Higher levels of IL‐1β, IL‐17 and IL‐22 were expressed in TMJ‐OA compared with DDWR subjects, and these increased levels significantly correlated with RANKL expression, joint pain and articular bone degeneration. Higher levels of CCR5, CCR6 and CCR7, as well as their respective ligands CCL5 and CCL20, responsible for recruitment of IL‐1β, IL‐17 and IL‐22‐producing cells, were over‐expressed in TMJ‐OA compared with DDWR subjects. Osteoclastogenesis and osteoclast‐induced bone resorption were significantly greater in presence of synovial fluid from TMJ‐OA compared with DDWR subjects. These data demonstrate that cytokines, CCLs and CCRs associated with the Th1/Th17/Th22 axis of immuno‐inflammatory response are involved in TMJ‐OA pathogenesis. These findings suggest that IL‐22 is involved in the RANKL expression in TMJ‐OA, which in turn induces differentiation of osteoclasts and subsequent resorption of sub‐chondral bone.  相似文献   
93.
94.
95.
BackgroundOur aims were to describe the first Mexican patient with abetalipoproteinemia and to perform a comparative analysis of biochemical, clinical, and genetic characteristics of 100 cases reported in the literature.MethodsWe performed biochemical and molecular screenings in a Mexican girl with extremely low lipid levels and in her family. Further, we integrated and evaluated the characteristics of the cases with abetalipoproteinemia described in the literature.ResultsOur patient is a six‐year‐old girl who presented vomiting, chronic diarrhea, failure to thrive, malabsorption, acanthocytosis, anemia, transaminases elevation, and extremely low lipid levels. MTTP gene sequencing revealed homozygosity for a novel mutation p.Gly417Valfs*12 (G deletion c.1250). With the analysis of the reported cases, 60 clinical features (14 classical and 46 non‐classical) were observed, being the most common acanthocytosis (57.5%), malabsorption (43.7%), and diarrhea (42.5%); 48.8% of the patients presented only classic clinical features, while the remaining 51.2% developed secondary effects due to a fat‐soluble vitamin deficiency. An odds ratio analysis disclosed that patients diagnosed after 10 years of age have an increased risk for presenting clinical complications (OR = 18.0; 95% CI 6.0‐54.1, p < 0.0001). A great diversity of mutations in MTTP has been observed (n = 76, being the most common p.G865X and p.N139_E140) and some of them with possible residual activity.ConclusionThe first Mexican patient with abetalipoproteinemia presents a novel MTTP mutation p.Gly417Valfs*12. Three factors that could modulate the phenotype in abetalipoproteinemia were identified: age at diagnosis, treatment, and the causal mutation.  相似文献   
96.
This paper introduces the architecture of an emotion-aware ambient intelligent and gerontechnological project named “Improvement of the Elderly Quality of Life and Care through Smart Emotion Regulation”. The objective of the proposal is to find solutions for improving the quality of life and care of the elderly who can or want to continue living at home by using emotion regulation techniques. A series of sensors is used for monitoring the elderlies’ facial and gestural expression, activity and behaviour, as well as relevant physiological data. This way the older people’s emotions are inferred and recognized. Music, colour and light are the stimulating means to regulate their emotions towards a positive and pleasant mood. Then, the paper proposes a gerontechnological software architecture that enables real-time, continuous monitoring of the elderly and provides the best-tailored reactions of the ambience in order to regulate the older person’s emotions towards a positive mood. After describing the benefits of the approach for emotion recognition and regulation in the elderly, the eight levels that compose the architecture are described.  相似文献   
97.
98.
IntroductionQuestionnaires to evaluate hand function are variable in the number of items, domains and diseases in which they had been previously used.Objectivesa) To translate to Spanish and validate the m-SACRAH and AUSCAN questionnaires; b) to do a transcultural adaptation of DASHe, previously validated in Spain), and c) to compare them and the Cochin questionnaire (previously validated in México), in rheumatic patients with variable impairment of hand function.Material and methodsm-SACRAH, AUSCAN and DASH were translated/retro-translated and adapted. The final version was revised to determine content validity and them, plus Cochin were applied to 10 healthy subjects (pilot study) with a variable educational level and in 16 rheumatic patients with variable diagnoses and degrees of hand function impairment; all patients answered 4 questionnaires and were evaluated clinically by blinded investigators.ResultsSeventy six percent were women, mean age 45.7 ± 11.4 years. Cronbach?s alpha > 0.90; time to answer went from 2.3 ± 0.087 (AUSCAN) to 3.5 ± 0.36 minutes (DASH). There was good correlation among them (r = 0.0683 AUSCAN-m-SACRAH to r = 0.889 AUSCAN-DASH) and good capability for discrimination between patients with mild VS moderate to severe impairment was also demonstrated; patients with mild impairment needed less time to answer them and there were no significant differences among questionnaire scores. Patients prefered AUSCAN (10/16), Cochin (4/16) and m-SACRAH (2/16).ConclusionThe 4 questionnaires are useful to evaluate hand function in rheumatic patients and have good discrimination capability. More patients preferred AUSCAN.  相似文献   
99.
The antimicrobial and antiparasite activity of phospholipase A2 (PLA2) from snakes and bees has been extensively explored. We studied the antiplasmodial effect of the whole venom of the snake Bothrops asper and of two fractions purified by ion-exchange chromatography: one containing catalytically-active phospholipases A2 (PLA2) (fraction V) and another containing a PLA2 homologue devoid of enzymatic activity (fraction VI). The antiplasmodial effect was assessed on in vitro cultures of Plasmodium falciparum. The whole venom of B. asper, as well as its fractions V and VI, were active against the parasite at 0.13 ± 0.01 µg/mL, 1.42 ± 0.56 µg/mL and 22.89 ± 1.22 µg/mL, respectively. Differences in the cytotoxic activity on peripheral blood mononuclear cells between the whole venom and fractions V and VI were observed, fraction V showing higher toxicity than total venom and fraction VI. Regarding toxicity in mice, the whole venom showed the highest lethal effect in comparison to fractions V and VI. These results suggest that B. asper PLA2 and its homologue have antiplasmodial potential.  相似文献   
100.
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