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   81063篇
  免费   7477篇
  国内免费   5289篇
耳鼻咽喉   575篇
儿科学   1017篇
妇产科学   1235篇
基础医学   9791篇
口腔科学   1581篇
临床医学   10282篇
内科学   12714篇
皮肤病学   839篇
神经病学   4410篇
特种医学   2914篇
外国民族医学   32篇
外科学   7787篇
综合类   13006篇
现状与发展   14篇
一般理论   12篇
预防医学   5514篇
眼科学   2118篇
药学   8702篇
  80篇
中国医学   4329篇
肿瘤学   6877篇
  2024年   330篇
  2023年   1295篇
  2022年   3200篇
  2021年   4074篇
  2020年   3083篇
  2019年   2633篇
  2018年   2812篇
  2017年   2517篇
  2016年   2367篇
  2015年   3603篇
  2014年   4375篇
  2013年   4116篇
  2012年   6196篇
  2011年   6523篇
  2010年   4212篇
  2009年   3309篇
  2008年   4457篇
  2007年   4280篇
  2006年   3888篇
  2005年   3816篇
  2004年   2754篇
  2003年   2503篇
  2002年   2242篇
  2001年   1825篇
  2000年   1910篇
  1999年   2008篇
  1998年   1296篇
  1997年   1282篇
  1996年   1004篇
  1995年   969篇
  1994年   794篇
  1993年   499篇
  1992年   560篇
  1991年   515篇
  1990年   440篇
  1989年   407篇
  1988年   318篇
  1987年   318篇
  1986年   243篇
  1985年   192篇
  1984年   127篇
  1983年   92篇
  1982年   65篇
  1981年   54篇
  1980年   43篇
  1979年   46篇
  1978年   22篇
  1974年   17篇
  1973年   17篇
  1966年   18篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
AClinicalStudyofReversingLeftVentricularHypertrophyinHypertensivePatientsbyAdalatZhangFumin(张馥敏)XuDi(许迪)YongYonghong(雍永宏)Chen...  相似文献   
12.
13.
本文报告用亚致死剂量的 S—31183(类保幼激素)处理三带喙库蚊幼虫对其发育影响的研究,结果表明处理后蛹期死亡率明显高于幼虫期,并且与剂量大小有关。S—31183处理幼虫并不影响幼虫的发育时间,但可使幼虫化蛹时蜕皮受阻与羽化受到一定的抑制。  相似文献   
14.
Nerve growth factor (NGF) gene expression in central nervous system (CNS) glia appears to be associated with active glial growth. To study the underlying molecular mechanisms, we examined the effects of a number of growth-related factors on NGF mRNA expression in glial cultures. Our results suggest that glial membrane interaction, as a consequence of growth, actively inhibits NGF gene expression in CNS glia.  相似文献   
15.
白纹伊蚊在竹林里孳生的阳性比为75.4%;而在竹林包围的居民区阳性比为15.3%。白纹伊蚊在居民区孳生密度布雷图指数为19.4,容器指数为6.2%。居民区孳生蚊虫的主要场所是泡菜坛,泡菜坛主要孳生蚊种是骚扰阿蚊,阳性比为73.7%,其次是淡色库蚊为20.2%,贪食库蚊为14.0%,白纹伊蚊最低,为9.1%。  相似文献   
16.
Adrenergic signalling between rat taste receptor cells   总被引:2,自引:0,他引:2  
In taste buds, synaptic transmission is traditionally thought to occur from taste receptor cells to the afferent nerve. This communication reports the novel observation that taste receptor cells respond to adrenergic stimulation. Noradrenaline application inhibited outward potassium currents in a dose-dependent manner. This inhibition was mimicked by the β agonist isoproterenol and blocked by the β antagonist propranolol. The α agonists clonidine and phenylephrine both inhibited the potassium currents and elevated intracellular calcium levels. Inwardly rectifying potassium currents were unaffected by adrenergic stimulation. Experiments using the RT-PCR technique demonstrate that lingual epithelium expresses multiple α (α1a, α1b, α1c, α1d, α2a, α2b, α2c) and β (β1, β2) subtypes of adrenergic receptors, and immunocytochemistry localized noradrenaline to a subset of taste receptor cells. Collectively, these data imply strongly that adrenergic transmission within the taste bud may play a paracrine role in taste physiology.  相似文献   
17.
目的 探讨严重创伤后肝细胞凋亡及坏死在急性肝功能障碍发病机制中的作用。方法复制多发性骨折合并休克的大鼠创伤模型,采用 Annexin-V-Flous、碘化丙锭(propidium iodid,PI)双标法经流式细胞仪检测创伤后各时间点肝细胞凋亡与坏死的数量变化,结合光镜、电镜和电泳观察细胞凋亡与坏死,并与肝功能变化相比较。结果创伤后早期肝细胞即发生凋亡和坏死,坏死肝细胞的数量进行性升高,与肝功能变化显著呈正相关;凋亡肝细胞在创伤后3h达高峰,部分凋亡肝细胞发生继发性坏死,其数量与肝功能变化显著正相关。结论肝细胞坏死与凋亡是严重创伤后肝功能损害的重要原因,坏死肝细胞是肝功能损害的直接因素,凋亡肝细胞通过发生继发性坏死加重肝功能损害。  相似文献   
18.
Abstract   We evaluated the associations between glycemic therapies and prevalence of diabetic peripheral neuropathy (DPN) at baseline among participants in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial on medical and revascularization therapies for coronary artery disease (CAD) and on insulin-sensitizing vs. insulin-providing treatments for diabetes. A total of 2,368 patients with type 2 diabetes and CAD was evaluated. DPN was defined as clinical examination score >2 using the Michigan Neuropathy Screening Instrument (MNSI). DPN odds ratios across different groups of glycemic therapy were evaluated by multiple logistic regression adjusted for multiple covariates including age, sex, hemoglobin A1c (HbA1c), and diabetes duration. Fifty-one percent of BARI 2D subjects with valid baseline characteristics and MNSI scores had DPN. After adjusting for all variables, use of insulin was significantly associated with DPN (OR = 1.57, 95% CI: 1.15–2.13). Patients on sulfonylurea (SU) or combination of SU/metformin (Met)/thiazolidinediones (TZD) had marginally higher rates of DPN than the Met/TZD group. This cross-sectional study in a cohort of patients with type 2 diabetes and CAD showed association of insulin use with higher DPN prevalence, independent of disease duration, glycemic control, and other characteristics. The causality between a glycemic control strategy and DPN cannot be evaluated in this cross-sectional study, but continued assessment of DPN and randomized therapies in BARI 2D trial may provide further explanations on the development of DPN.  相似文献   
19.
我在20世纪80年代初期,曾发表“北方亦多湿论”的短文,但失之过简,今按四时更迭,主要节令交替详细阐述之。在未入正题之前,先读一下毛主席的《沁园春·雪》,俾对北方气候有所了解:“北国风光,千里冰封,万里雪飘,望长城内外,惟余莽莽,大河上下,顿失滔滔。山舞银蛇,原驰蜡象,欲与  相似文献   
20.
BACKGROUND AND PURPOSE: The catastrophic Chi-Chi earthquake of September 21, 1999 in Taiwan provided a unique opportunity to study the disaster's psychiatric impact on survivors. This study assessed the development of psychiatric disorders among residents in a Taiwanese village near the epicenter of the earthquake within 6 months of the disaster. METHODS: A total of 442 of the 602 actual living residents of Tong-Chi village who were over 16 years of age and were present in the community at the time of the earthquake were included in this population survey. Subjects were interviewed by psychiatrists using the Mini-International Neuropsychiatric Interview and questionnaires to collect demographic information and risk factors for psychiatric disorders 4 to 6 months after the earthquake. RESULTS: The prevalence rates were 9.5% for current major depression, 2.8% for past major depressive episode, and 7.9% for post-traumatic stress disorder (PTSD). Females had significantly higher rates of most psychiatric disorders. After controlling for covariates, the significant risk factors for PTSD were female gender and having sought medical service after the earthquake. Significant risk factors for major depressive episode were divorced/widowed status, education level equal to or below primary school, and prominent house damage. CONCLUSION: This population survey of earthquake disaster survivors found an increased prevalence of psychiatric disorders after exposure to a catastrophic earthquake. These results highlight the need for prompt therapeutic attention to residents of earthquake disaster areas after the event.  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