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   149350篇
  免费   13498篇
  国内免费   9858篇
耳鼻咽喉   1165篇
儿科学   1841篇
妇产科学   2583篇
基础医学   17402篇
口腔科学   2605篇
临床医学   19559篇
内科学   23330篇
皮肤病学   1741篇
神经病学   7959篇
特种医学   5133篇
外国民族医学   82篇
外科学   15205篇
综合类   23820篇
现状与发展   31篇
一般理论   7篇
预防医学   9625篇
眼科学   4157篇
药学   15439篇
  149篇
中国医学   8255篇
肿瘤学   12618篇
  2024年   399篇
  2023年   2116篇
  2022年   5065篇
  2021年   7392篇
  2020年   5459篇
  2019年   4940篇
  2018年   5070篇
  2017年   4643篇
  2016年   4253篇
  2015年   6367篇
  2014年   7964篇
  2013年   7373篇
  2012年   10749篇
  2011年   11691篇
  2010年   7247篇
  2009年   5790篇
  2008年   7617篇
  2007年   7702篇
  2006年   7601篇
  2005年   7431篇
  2004年   5304篇
  2003年   5231篇
  2002年   4470篇
  2001年   3987篇
  2000年   3799篇
  1999年   3867篇
  1998年   2500篇
  1997年   2453篇
  1996年   1779篇
  1995年   1647篇
  1994年   1419篇
  1993年   904篇
  1992年   1378篇
  1991年   1193篇
  1990年   1004篇
  1989年   897篇
  1988年   773篇
  1987年   717篇
  1986年   545篇
  1985年   495篇
  1984年   278篇
  1983年   191篇
  1982年   128篇
  1981年   122篇
  1980年   79篇
  1979年   130篇
  1978年   59篇
  1976年   52篇
  1975年   55篇
  1974年   65篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
In a biological microenvironment, free fatty acids (FFA) as ubiquitous biological molecules might interact with nanoparticles (NPs) and consequently change the toxicological responses. However, whether the chemical structures of FFA could influence their interactions with NPs remain unknown. This study investigated the interactions between ZnO NPs and saturated or unsaturated FFA (complexed to BSA), namely stearic acid (SA, C18:0), oleic acid (OA, C18:1), and α-linolenic acid (ALA, C18:3). It was shown that BSA, SA, OA, and ALA increased the atomic force microscope (AFM) heights as well the polydispersity index (PDI) of ZnO NPs. BSA modestly protected THP-1 macrophages from ZnO NP exposure, whereas OA and ALA led to relatively less cyto-protective effects of BSA. Moreover, only co-exposure to ZnO NPs and SA significantly promoted the release of interleukin-8. BSA, SA, OA, and ALA equally changed intracellular ROS and Zn ions associated with ZnO exposure, but co-exposure to ZnO NPs and OA/ALA particularly activated the expression of endoplasmic reticulum stress-apoptosis genes. In combination, these results showed that FFA could influence the colloidal aspects and toxicological signaling pathway of ZnO NPs, which is dependent on the number of unsaturated bonds of FFA.  相似文献   
82.
Stress has been suggested to disturb the 5-hydroxytryptamine system and decrease neurogenesis, which contribute to the development of depression. Few studies have investigated the effect of predator stress, a type of psychological stress, on depression and hippocampal neurogenesis in adult mice; we therefore investigated this in the present study. A total of 35 adult male Kunming mice were allocated to a cat stress group, cat odor stress group, cat stress + fluoxetine group, cat odor stress + fluoxetine group, or a control group(no stress/treatment). After 12 days of cat stress or cat odor stress, behavioral correlates of depression were measured using the open field test, elevated plus maze test, and dark-avoidance test. The concentrations of hippocampal 5-hydroxytryptamine and 5-hydroxyindoleacetic acid were measured using high-performance liquid chromatography-electrochemical detection. Neurogenesis was also analyzed using a bromodeoxyuridine and doublecortin double-immunostaining method. Cat stress and cat odor stress induced depression-like behaviors; this effect was stronger in the cat stress model. Furthermore, compared with the control group, cat stress mice exhibited lower 5-hydroxytryptamine concentrations, higher 5-hydroxyindoleacetic acid concentrations, and significantly fewer bromodeoxyuridine+/doublecortin+-labeled cells in the dentate gyrus, which was indicative of less neurogenesis. The changes observed in the cat stress group were not seen in the cat stress + fluoxetine group, which suggests that the effects of predator stress on depression and neurogenesis were reversed by fluoxetine. Taken together, our results indicate that depression-like behaviors induced by predator stress are associated with the inhibition of hippocampal neurogenesis.  相似文献   
83.
本着以课程为中心的原则,研究组在基础医学综合实验课程建设、运行方式、教学方法改革等方面积极探索;以联系疾病、联系应用为导向,广泛开展基于疾病动物模型制备及干预过程的实验教学;增加"创新性"实验项目,确保课程内容体现出前沿性和时代性;以生物医学前沿方法训练引领课程建设,着力培养学员的学习能力、实践能力和创新能力。此外,在优化以实践应用、创新性为导向的课程内容建设的基础上,打造虚拟仿真实验项目,尝试线上线下混合式教学,全方位提升学员的实践运用能力。  相似文献   
84.
85.
86.
87.

Purpose

To evaluate the feasibility of a same-day yttrium-90 (90Y) radioembolization protocol with resin microspheres (including pretreatment angiography, lung shunt fraction [LSF] determination, and radioembolization) for the treatment of hepatocellular carcinoma (HCC) and liver metastases.

Materials and Methods

All same-day radioembolization procedures performed over 1 y (February 2017 to January 2018) were included in this single-institutional retrospective analysis, in which 34 procedures were performed in 26 patients (median age, 63 y; 13 women), 19 with liver metastases and 7 with HCC. Yttrium-90 treatment activities were calculated by body surface area method. Tumor imaging response was assessed by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 for liver metastases and modified RECIST for HCC. Clinical side effects and adverse events were graded per Common Terminology Criteria for Adverse Events version 4.0.

Results

All planned cases were technically successful, and no cases were canceled for elevated LSF or vascular anatomic reasons. Pretreatment angiography modified the planned 90Y treatment activity in 1 case in which vascular anatomy required a lobar-dose split into 2 for segmental infusions. In 18% of cases, patients were briefly admitted after the procedure for observation or symptom management. Imaging evaluation of initial efficacy at 1 month demonstrated partial response in 25% and stable disease in 67% of patients with liver metastases and partial/complete response in 43% and stable disease in 14% of patients with HCC. Grade ≥ 3 adverse events occurred in 6% of cases, with no systemic therapy–limiting toxicities. The mean total procedure time was 4.2 hours.

Conclusions

A same-day 90Y radioembolization protocol with resin microspheres is feasible in select patients, which can expedite cancer therapy.  相似文献   
88.
89.
90.
全国名中医天津中医药大学第一附属医院针灸科武连仲教授用多年的临床经验总结概括出针刺的理、法、方、穴、术,其创立的"通经止痛"针刺疗法在临床中疗效佳,武老在治疗坐骨神经痛时,取足太阳膀胱经和足少阳胆经具有走窜针感的经穴为主穴,其配伍精确,组方严密,手法独特,可供临床参考。本文将武老运用"痛经止痛"针刺法治疗坐骨神经痛的经验从"理、法、方、穴、术"方面做浅述。  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