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   24409篇
  免费   1934篇
  国内免费   1748篇
耳鼻咽喉   242篇
儿科学   333篇
妇产科学   343篇
基础医学   3185篇
口腔科学   439篇
临床医学   3137篇
内科学   4079篇
皮肤病学   293篇
神经病学   1379篇
特种医学   750篇
外国民族医学   15篇
外科学   2697篇
综合类   3399篇
现状与发展   6篇
一般理论   2篇
预防医学   1540篇
眼科学   577篇
药学   2468篇
  13篇
中国医学   1013篇
肿瘤学   2181篇
  2024年   64篇
  2023年   318篇
  2022年   774篇
  2021年   1030篇
  2020年   811篇
  2019年   685篇
  2018年   808篇
  2017年   675篇
  2016年   663篇
  2015年   983篇
  2014年   1291篇
  2013年   1067篇
  2012年   1724篇
  2011年   1767篇
  2010年   1046篇
  2009年   874篇
  2008年   1260篇
  2007年   1230篇
  2006年   1237篇
  2005年   1344篇
  2004年   801篇
  2003年   799篇
  2002年   707篇
  2001年   589篇
  2000年   706篇
  1999年   719篇
  1998年   452篇
  1997年   454篇
  1996年   347篇
  1995年   340篇
  1994年   262篇
  1993年   193篇
  1992年   310篇
  1991年   254篇
  1990年   243篇
  1989年   239篇
  1988年   196篇
  1987年   173篇
  1986年   146篇
  1985年   153篇
  1984年   58篇
  1983年   59篇
  1982年   23篇
  1981年   34篇
  1979年   22篇
  1978年   12篇
  1974年   20篇
  1973年   14篇
  1972年   16篇
  1969年   13篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
91.
92.
目的:研究流动注射-CCD二极管阵列检测分光光度法测定尿中肌酐含量的方法。方法:基于经典的Jaffe反应,肌酐能与碱性苦味酸生成橙红色复合物,利用化学动力学反应,采用CCD二极管阵列检测装置快速测定尿中肌酐的含量。本实验探讨了最佳反应条件和流动注射分析参数。结果:本方法的线性范围为1μg/ml~33μg/ml,检出限为1μg/ml。样品的加标回收率在81.63%~119.7%之间,精密度为2.74%~3.96%。将本方法与临床自动生化仪的测定结果比较,经t检验(t=0.179,P〉0.05),两种方法测定结果无统计学差异。结论:本方法采样频率为20次/11,简便快速、分析成本低,实现了尿中肌酐含量的批样分析,获得了满意的结果。  相似文献   
93.
文章结合实践介绍了实验动物和脏器标本的摄影方法及注意事项,为从事这方面工作的科技人员提供了技术支持。  相似文献   
94.
Despite recent progress in the identification and characterization of numerous nasal biotransformation enzymes in laboratory animals, the expression of biotransformation genes in human nasal mucosa remains difficult to study. Given the potential role of nasal biotransformation enzymes in the metabolism of airborne chemicals, including fragrance compounds and therapeutic agents, as well as the potential interspecies differences between laboratory animals and humans, it would be highly desirable to identify those biotransformation genes that are expressed in human nasal mucosa. In this study, a global gene expression analysis was performed to compare biotransformation enzymes expressed in human fetal and adult nasal mucosa to those expressed in liver. The identities of a list of biotransformation genes with apparently nasal mucosa-selective expression were subsequently confirmed by RNA-polymerase chain reaction (PCR) and DNA sequencing of the PCR products. Further quantitative RNA-PCR experiments indicated that, in the fetus, aldehyde dehydrogenase 6 (ALDH6), CYP1B1, CYP2F1, CYP4B1, and UDP glucuronosyltransferase 2A1 are expressed preferentially in the nasal mucosa and that ALDH7, flavin-containing monooxygenase 1, and glutathione S-transferase P1 are at least as abundant in the nasal mucosa as in the liver. The nasal mucosal expression of CYP2E1 was also detected. These findings provide a basis for further explorations of the metabolic capacity of the human nasal mucosa for xenobiotic compounds.  相似文献   
95.
穿心莲内酯微囊的制备及溶出度考察   总被引:6,自引:0,他引:6  
目的:研究以丙烯酸树脂Ⅳ号为囊材的穿心莲内酯微囊的制备方法及其体外溶出特点.方法:采用液中干燥法制备穿心莲内酯微囊,并按<中国药典>方法测定体外溶出度.结果:该法制备的穿心莲内酯微囊,在水中药物几乎没有溶出,而在酸性溶出介质中则可快速释放.结论:该方法所制备微囊不仅可以有效掩盖穿心莲内酯的苦味,而且在胃液中能够快速释放.  相似文献   
96.
2019年9—12月,笔者参与了苏州大学与德国柏林Pflgewerk养老机构针对失能老年人居家照护课程研发与智慧化养老的交流项目,在学习与交流期间,德国完善的居家照护体系,先进适老辅具的研发与运用,系统规范的照护员培训课程,浓厚的人文关怀气氛与多学科团队合作的安宁疗护中心令笔者印象深刻。本文结合学习交流活动的亲身经历,...  相似文献   
97.
Breast surgery is an important treatment for women with malignant breast diseases. In addition to breast appearance, the integrity of breast function is increasing in patients with breast diseases. As the basis of breast physiological function, breast skin sensitivity is important to the quality of life of patients after surgery. Breast skin sensitivity gives the patient a “real” breast feeling. The sensory recovery after breast surgery has also become one of the important goals of breast surgery. In this review, we aim to discuss the research progress on recovery of breast skin sensitivity after different treatment modalities for breast disease.  相似文献   
98.
Plant-derived polyphenols flavonoids are increasingly being recognized for their medicinal potential. These bioactive compounds derived from plants are gaining more interest in ameliorating adverse health risks because of their low toxicity and few side effects. Among them, therapeutic approaches demonstrated the efficacy of catechins, a major group of flavonoids, in reverting several aspects of Down syndrome, the most common genomic disorder that causes intellectual disability. Down syndrome is characterized by increased incidence of developing Alzheimer’s disease, obesity, and subsequent metabolic disorders. In this focused review, we examine the main effects of catechins on comorbidities linked with Down syndrome. We also provide evidence of catechin effects on DYRK1A, a dosage-sensitive gene encoding a protein kinase involved in brain defects and metabolic disease associated with Down syndrome.  相似文献   
99.
ContextDeer antler based active ingredients are known to have certain anti-inflammatory and antioxidant activities. However, its potential hepatoprotective effect remains unclear.ObjectiveThis article reports the hepatoprotective effect of protein components in deer antler bases (R1) on lipopolysaccharide/d-galactosamine (LPS/d-GalN)-induced acute liver injury (ALI) in mice, and explores its possible mechanism.Materials and methodsThe four separated and purified protein components of deer antler bases were screened and verified by the RAW264.7 cell inflammation model. In the in vivo experiment of LPS/d-GalN-induced ALI in mice, ALT, AST, SOD, CAT, GSH and MDA were detected. The liver histopathology was analysed, the COX-2 and iNOS proteins were analysed by immunohistochemistry, and 4-HNE was analysed by immunofluorescence staining. In addition, the effects on the MAPK pathway and NF-κB/IκB-α pathway in liver proteins were explored.ResultsWith isolated RA protein fraction pre-treated RAW264.7 cells, NO production decreased by 35.3% compared with the model group. The experimental results of ALI in mice induced by LPS/d-GalN show that R1 protein components can protect mice from ALI through anti-inflammatory and anti-oxidative stress effects and reduce liver pathological damage in mice. The results also indicate that the R1 protein component may protect the liver by inhibiting the activation of the MAPK pathway and the NF-κB/IκB-α pathway induced by LPS/d-GalN.ConclusionsThe separated and purified R1 protein component of deer antler base has a good protective effect on LPS/d-GalN-induced liver injury, and may become a potential material for protecting against liver injury.  相似文献   
100.
目的:研究益肾蠲痹法治疗系统性红斑狼疮的疗效.方法:本研究应用"益肾蠲痹法"对54例曾用激素或免疫抑制剂治疗系统性红斑狼疮,因副作用而改用益肾蠲痹法治疗3年以上的患者,观察治疗前后临床疗效、症状积分、激素剂量、血沉、C反应蛋白、ENA系列等指标变化.结果:54例系统性红斑狼疮患者治疗后的症状积分显著下降,ESR、CRP明显下降;激素用量逐渐撤减至停服,ENA系列指标阴转率最高达96.3%.结论:益肾蠲痹法对难治性系统性红斑狼疮,具有疗效高、毒副作用小、症状及实验室指标改善明显等理想疗效,是一种易于推广使用、具有良好产业化前景的治疗方法.  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