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   45551篇
  免费   3300篇
  国内免费   2658篇
耳鼻咽喉   422篇
儿科学   671篇
妇产科学   707篇
基础医学   8661篇
口腔科学   815篇
临床医学   3290篇
内科学   7194篇
皮肤病学   481篇
神经病学   2944篇
特种医学   1186篇
外国民族医学   8篇
外科学   3873篇
综合类   8480篇
现状与发展   2篇
预防医学   2224篇
眼科学   507篇
药学   3559篇
  4篇
中国医学   1168篇
肿瘤学   5313篇
  2024年   35篇
  2023年   318篇
  2022年   687篇
  2021年   997篇
  2020年   881篇
  2019年   764篇
  2018年   827篇
  2017年   1088篇
  2016年   1178篇
  2015年   1352篇
  2014年   2110篇
  2013年   2456篇
  2012年   2432篇
  2011年   2975篇
  2010年   2568篇
  2009年   2601篇
  2008年   3082篇
  2007年   3347篇
  2006年   3304篇
  2005年   3242篇
  2004年   2738篇
  2003年   2490篇
  2002年   1925篇
  2001年   1680篇
  2000年   1345篇
  1999年   1132篇
  1998年   861篇
  1997年   738篇
  1996年   496篇
  1995年   440篇
  1994年   354篇
  1993年   223篇
  1992年   180篇
  1991年   135篇
  1990年   134篇
  1989年   101篇
  1988年   74篇
  1987年   39篇
  1986年   39篇
  1985年   41篇
  1984年   20篇
  1983年   10篇
  1982年   19篇
  1981年   17篇
  1980年   13篇
  1979年   8篇
  1977年   3篇
  1975年   2篇
  1973年   2篇
  1971年   2篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
《Survey of ophthalmology》2023,68(5):940-956
Congenital aniridia is a panocular disorder that is typically characterized by iris hypoplasia and aniridia-associated keratopathy (AAK). AAK results in the progressive loss of corneal transparency and thereby loss of vision. Currently, there is no approved therapy to delay or prevent its progression, and clinical management is challenging because of phenotypic variability and high risk of complications after interventions; however, new insights into the molecular pathogenesis of AAK may help improve its management. Here, we review the current understanding about the pathogenesis and management of AAK. We highlight the biological mechanisms involved in AAK development with the aim to develop future treatment options, including surgical, pharmacological, cell therapies, and gene therapies.  相似文献   
3.
Lipid nanoparticles (LNPs) are becoming popular as a means of delivering therapeutics, including those based on nucleic acids and mRNA. The mRNA-based coronavirus disease 2019 vaccines are perfect examples to highlight the role played by drug delivery systems in advancing human health. The fundamentals of LNPs for the delivery of nucleic acid- and mRNA-based therapeutics, are well established. Thus, future research on LNPs will focus on addressing the following: expanding the scope of drug delivery to different constituents of the human body, expanding the number of diseases that can be targeted, and studying the change in the pharmacokinetics of LNPs under physiological and pathological conditions. This review article provides an overview of recent advances aimed at expanding the application of LNPs, focusing on the pharmacokinetics and advantages of LNPs. In addition, analytical techniques, library construction and screening, rational design, active targeting, and applicability to gene editing therapy have also been discussed.  相似文献   
4.
ABSTRACT

This project examined 55 picture books featuring transgender, gender expansive or genderqueer protagonists or narrators published between 2008 and 2018. The purpose of the study was to determine how this genre of children’s literature supports and challenges four gender assumptions: the gender binary, gender essentialism, sex/gender congruency and gender stability. Additionally, this critical analysis explored misgendering within this genre and themes of social rejection and acceptance. Protagonists and narrators were permitted a degree of gender nonconformity, however, the majority of picture books missed opportunities for a more complete exploration of gender possibilities.  相似文献   
5.
6.
7.
Hepatic uptake mediated by organic anion transporting polypeptide (OATP) 1B1 and 1B3 can serve as a major elimination pathway for various anionic drugs and as a site of drug-drug interactions (DDIs). This article provides an overview of the in vitro approaches used to predict human hepatic clearance (CLh) and the risk of DDIs involving OATP1Bs. On the basis of the so-called extended clearance concept, in vitro–in vivo extrapolation methods using human hepatocytes as in vitro systems have been used to predict the CLh involving OATP1B-mediated hepatic uptake. CLh can be quantitatively predicted using human donor lots possessing adequate OATP1B activities. The contribution of OATP1Bs to hepatic uptake can be estimated by the relative activity factor, the relative expression factor, or selective inhibitor approaches, which offer generally consistent outcomes. In OATP1B1 inhibition assays, substantial substrate dependency was observed. The time-dependent inhibition of OATP1B1 was also noted and may be a mechanism underlying the in vitro–in vivo differences in the inhibition constant of cyclosporine A. Although it is still challenging to quantitatively predict CLh and DDIs involving OATP1Bs from only preclinical data, understanding the utility and limitation of the current in vitro methods will pave the way for better prediction.  相似文献   
8.
目的探讨体外转染细胞周期素A2(Cyclin A2)基因对原代大鼠心肌细胞增殖的影响,为心脏再生提供细胞学依据。方法 SD乳鼠12只,分离、培养、鉴定原代乳鼠心肌细胞并分为3组,实验组:转染带有强化绿色荧光蛋白(GFP)和Cyclin A2基因的重组腺病毒(Ad-Cyclin A2-GFP);空病毒组:转染不含目的基因带有GFP的重组腺病毒(Ad-Null-GFP);阴性对照组:未做转染处理,仅加入等量的培养基。利用GFP示踪技术,评估原代心肌细胞转染效率;转染后的细胞继续体外培养3~5d,利用免疫荧光技术分别检测Cyclin A2、磷酸化组蛋白H3(H3P)、心肌肌钙蛋白-T(c Tn T)。结果 1.荧光GFP示踪表明原代心肌细胞的转染效率高达(97±0.74)%;2.免疫荧光标记显示,空病毒组和对照组结果相似;心肌细胞特异性标记蛋白c Tn T分布于细胞质,原代心肌细胞纯度高达(95±0.62)%;心肌细胞Cyclin A2主要在胞核内聚集,少数分布于细胞质。H3P为核蛋白在细胞核内分布。3.转染Cyclin A2后,实验组H3P阳性率明显高于空病毒组和对照组,差异具有统计学意义(P0.05);实验组可见大量多核细胞,以双核为主,伴少量3核细胞。结论腺病毒作为转染载体对原代心肌细胞有很好的侵染效率;Cyclin A2超表达促进原代心肌细胞形成双核。  相似文献   
9.
10.
Autoimmune thyroid diseases (AITD) and Type 1 diabetes (T1D) frequently occur in the same individual pointing to a strong shared genetic susceptibility. Indeed, the co-occurrence of T1D and AITD in the same individual is classified as a variant of the autoimmune polyglandular syndrome type 3 (designated APS3v). Our aim was to identify new genes and mechanisms causing the co-occurrence of T1D + AITD (APS3v) in the same individual using a genome-wide approach. For our discovery set we analyzed 346 Caucasian APS3v patients and 727 gender and ethnicity matched healthy controls. Genotyping was performed using the Illumina Human660W-Quad.v1. The replication set included 185 APS3v patients and 340 controls. Association analyses were performed using the PLINK program, and pathway analyses were performed using the MAGENTA software. We identified multiple signals within the HLA region and conditioning studies suggested that a few of them contributed independently to the strong association of the HLA locus with APS3v. Outside the HLA region, variants in GPR103, a gene not suggested by previous studies of APS3v, T1D, or AITD, showed genome-wide significance (p < 5 × 10−8). In addition, a locus on 1p13 containing the PTPN22 gene showed genome-wide significant associations. Pathway analysis demonstrated that cell cycle, B-cell development, CD40, and CTLA-4 signaling were the major pathways contributing to the pathogenesis of APS3v. These findings suggest that complex mechanisms involving T-cell and B-cell pathways are involved in the strong genetic association between AITD and T1D.  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