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   30502篇
  免费   3375篇
  国内免费   899篇
耳鼻咽喉   34篇
儿科学   1144篇
妇产科学   142篇
基础医学   2003篇
口腔科学   109篇
临床医学   2890篇
内科学   3975篇
皮肤病学   151篇
神经病学   191篇
特种医学   717篇
外国民族医学   1篇
外科学   11936篇
综合类   4800篇
一般理论   1篇
预防医学   881篇
眼科学   24篇
药学   2467篇
  15篇
中国医学   2766篇
肿瘤学   529篇
  2024年   35篇
  2023年   791篇
  2022年   915篇
  2021年   1786篇
  2020年   1582篇
  2019年   1619篇
  2018年   1418篇
  2017年   1502篇
  2016年   1443篇
  2015年   1467篇
  2014年   2419篇
  2013年   2456篇
  2012年   1728篇
  2011年   1879篇
  2010年   1562篇
  2009年   1385篇
  2008年   1377篇
  2007年   1265篇
  2006年   1159篇
  2005年   981篇
  2004年   851篇
  2003年   708篇
  2002年   608篇
  2001年   565篇
  2000年   380篇
  1999年   313篇
  1998年   265篇
  1997年   209篇
  1996年   219篇
  1995年   219篇
  1994年   206篇
  1993年   161篇
  1992年   162篇
  1991年   152篇
  1990年   117篇
  1989年   121篇
  1988年   81篇
  1987年   89篇
  1986年   70篇
  1985年   68篇
  1984年   74篇
  1983年   40篇
  1982年   55篇
  1981年   51篇
  1980年   36篇
  1979年   46篇
  1978年   33篇
  1977年   30篇
  1976年   25篇
  1975年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
肾脏是人体最重要的排泄器官。肾单元近端小管细胞具有多种药物转运体和代谢酶,在药物及其代谢物处置中发挥关键作用。近端小管细胞中主要转运体包括有机阴离子转运体、有机阳离子转运体、有机阳离子/肉毒碱转运体、多药及毒素外排转运蛋白、P-糖蛋白、乳腺癌耐药蛋白和多药耐药相关蛋白;主要代谢酶包括细胞色素P450酶,UDP-葡萄糖醛酸基转移酶、磺酸基转移酶、谷胱甘肽S-转移酶。肾脏转运体和/或代谢酶介导药物相互作用(DDIs)是临床关注的重要问题。肾脏转运体和代谢酶存在密切协作关系,在肾脏也存在多种相互作用现象(包括转运-转运相互作用,代谢-代谢相互作用和转运-代谢相互作用),其显著影响药物肾脏处置、临床疗效和肾毒性。本文系统阐述了这些相互作用对药物及其代谢物的肾脏排泄、药动学、DDIs和肾毒性的影响。今后需要进一步阐明肾脏转运-代谢相互作用机制,将有助于研究体内药物肾脏处置和DDIs,促进临床合理用药。  相似文献   
2.
3.
Whether the underlying mutations are homozygous, heterozygous, or co-inherited with other hemoglobinopathies, sickle cell disease is known to afflict the kidneys, leading to the clinical entity known as sickle cell nephropathy (SCN). Although common, SCN remains diagnostically elusive. Conventional studies performed in the context of renal disorders often fail to detect early stage SCN. This makes the quest for early diagnosis and treatment more challenging, and it increases the burden of chronic kidney disease-related morbidity among patients. Novel diagnostic tools have been employed to overcome this limitation. In this study, we discuss various biomarkers of SCN, including those employed in clinical practice and others recently identified in experimental settings, such as markers of vascular injury, endothelial dysfunction, tubulo-glomerular damage, and oxidative stress. These include kidney injury molecule-1, monocyte chemoattractant protein-1, N-acetyl-B-D-glucosaminidase, ceruloplasmin, orosomucoid, nephrin, and cation channels, among others. Furthermore, we explore the potential of novel biomarkers for refining diagnostic and therapeutic approaches and describe some obstacles that still need to be overcome. We highlight the importance of a collaborative approach to standardize the use of promising new biomarkers. Finally, we outline the limitations of conventional markers of renal damage as extensions of the pathogenic process occurring at the level of the organ and its functional subunits, with a discussion of the expected pattern of clinical and biochemical progression among patients with SCN.  相似文献   
4.
5.
6.
流感是由流感病毒引发的急性呼吸道传染病,每年可引起季节性流行。疫苗接种是预防和控制流感流行和大流行期间病毒感染的主要方法,目前流感疫苗生产主要仍依赖鸡胚培养技术,但近年来,使用动物细胞基质代替鸡胚培养已成为流感疫苗技术创新的重要趋势。随着贴壁培养及无血清全悬浮培养等培养技术在生物制药领域的发展,已有多种动物细胞系用于流感疫苗生产。本文简要综述近年来动物细胞培养技术在流感疫苗研发中的应用进展。  相似文献   
7.
目的: 评价铁剂在慢性肾脏病(chronic kidney disease,CKD)患者使用中的合理性,为CKD5/5D期患者安全使用提供数据。方法: 回顾性分析了苏州大学附属第一医院(下称"我院")2020年出院的CKD患者的真实世界数据,制定铁剂使用规范,对使用铁剂的患者进行合理性评价,特别对CKD5/5D期患者使用铁剂的安全性进行了评估。结果: 共纳入254例患者,铁剂使用合理率为67.3%,潜在药物相互作用(drug-drug interactions,DDI)发生率72%,铁剂总ADR发生率为10.2%,CKD1~4期和CKD5/5D期ADR发生率分别为11.8%和10.0%(P>0.05)。存在潜在DDI的ADR发生率和无潜在DDI的ADR发生率分别为12%和5.6%(P>0.05)。结论: 我院CKD患者铁剂使用较为合理,CKD5/5D期患者使用铁剂安全性较高,DDI方面需要做好用药交代。  相似文献   
8.
The purpose of this study was to investigate the feasibility of two-dimensional (2D) navigated, interleaved multishot echo-planar imaging (EPI) to enhance kidney diffusion-weighted imaging (DWI) in rats at 7.0 T. Fully sampled interleaved four-shot EPI with 2D navigators was tailored for kidney DWI (Sprague–Dawley rats, n = 7) on a 7.0-T small bore preclinical scanner. The image quality of four-shot EPI was compared with T2-weighted rapid acquisition with relaxation enhancement (RARE) (reference) and single-shot EPI (ss-EPI) without and with parallel imaging (PI). The contrast-to-noise ratio (CNR) was examined to assess the image quality for the EPI approaches. The Dice similarity coefficient and the Hausdorff distance were used for evaluation of image distortion. Mean diffusivity (MD) and fractional anisotropy (FA) were calculated for renal cortex and medulla for all DWI approaches. The corticomedullary difference of MD and FA were assessed by Wilcoxon signed-rank test. Four-shot EPI showed the highest CNR among the three EPI variants and lowest geometric distortion versus T2-weighted RARE (mean Dice: 0.77 for ss-EPI without PI, 0.88 for ss-EPI with twofold undersampling, and 0.92 for four-shot EPI). The FA map derived from four-shot EPI clearly identified a highly anisotropic region corresponding to the inner stripe of the outer medulla. Four-shot EPI successfully discerned differences in both MD and FA between renal cortex and medulla. In conclusion, 2D navigated, interleaved multishot EPI facilitates high-quality rat kidney DWI with clearly depicted intralayer and interlayer structure and substantially reduced image distortion. This approach enables the anatomic integrity of DWI-MRI in small rodents and has the potential to benefit the characterization of renal microstructure in preclinical studies.  相似文献   
9.
《Clinical microbiology and infection》2022,28(8):1152.e1-1152.e6
ObjectivesDespite the possibility of concurrent infection with COVID-19 and malaria, little is known about the clinical course of coinfected patients. We analysed the clinical outcomes of patients with concurrent COVID-19 and malaria infection.MethodsWe conducted a retrospective cohort study that assessed prospectively collected data of all patients who were admitted between May and December 2020 to the Universal COVID-19 treatment center (UCTC), Khartoum, Sudan. UCTC compiled demographic, clinical, laboratory (including testing for malaria), and outcome data in all patients with confirmed COVID-19 hospitalized at that clinic. The primary outcome was all-cause mortality during the hospital stay. We built proportional hazard Cox models with malaria status as the main exposure and stepwise adjustment for age, sex, cardiovascular comorbidities, diabetes, and hypertension.ResultsWe included 591 patients with confirmed COVID-19 diagnosis who were also tested for malaria. Mean (SD) age was 58 (16.2) years, 446/591 (75.5%) were males. Malaria was diagnosed in 270/591 (45.7%) patients. Most malaria patients were infected by Plasmodium falciparum (140/270; 51.9%), while 121/270 (44.8%) were coinfected with Plasmodium falciparum and Plasmodium vivax. Median follow-up was 29 days. Crude mortality rates were 10.71 and 5.87 per 1000 person-days for patients with and without concurrent malaria, respectively. In the fully adjusted Cox model, patients with concurrent malaria and COVID-19 had a greater mortality risk (hazard ratio 1.43, 95% confidence interval 1.21-1.69).DiscussionCoinfection with COVID-19 and malaria is associated with increased all-cause in-hospital mortality compared to monoinfection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).  相似文献   
10.
Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent cause of genetic renal disease and accounts for 6–10% of patients on kidney replacement therapy (KRT).Very few prospective, randomized trials or clinical studies address the diagnosis and management of this relatively frequent disorder. No clinical guidelines are available to date. This is a revised consensus statement from the previous 2014 version, presenting the recommendations of the Spanish Working Group on Inherited Kidney Diseases, which were agreed to following a literature search and discussions. Levels of evidence mostly are C and D according to the Centre for Evidence-Based Medicine (University of Oxford). The recommendations relate to, among other topics, the use of imaging and genetic diagnosis, management of hypertension, pain, cyst infections and bleeding, extra-renal involvement including polycystic liver disease and cranial aneurysms, management of chronic kidney disease and KRT and management of children with ADPKD. Recommendations on specific ADPKD therapies are provided as well as the recommendation to assess rapid progression.  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