全文获取类型
收费全文 | 40214篇 |
免费 | 4115篇 |
国内免费 | 2862篇 |
专业分类
耳鼻咽喉 | 300篇 |
儿科学 | 585篇 |
妇产科学 | 517篇 |
基础医学 | 3521篇 |
口腔科学 | 590篇 |
临床医学 | 5497篇 |
内科学 | 4991篇 |
皮肤病学 | 345篇 |
神经病学 | 1504篇 |
特种医学 | 1336篇 |
外国民族医学 | 7篇 |
外科学 | 3133篇 |
综合类 | 8971篇 |
现状与发展 | 23篇 |
一般理论 | 1篇 |
预防医学 | 3681篇 |
眼科学 | 797篇 |
药学 | 5109篇 |
54篇 | |
中国医学 | 3329篇 |
肿瘤学 | 2900篇 |
出版年
2024年 | 156篇 |
2023年 | 559篇 |
2022年 | 1492篇 |
2021年 | 1854篇 |
2020年 | 1530篇 |
2019年 | 1160篇 |
2018年 | 1172篇 |
2017年 | 1337篇 |
2016年 | 1108篇 |
2015年 | 1877篇 |
2014年 | 2332篇 |
2013年 | 2416篇 |
2012年 | 3607篇 |
2011年 | 3626篇 |
2010年 | 2728篇 |
2009年 | 2237篇 |
2008年 | 2571篇 |
2007年 | 2619篇 |
2006年 | 2390篇 |
2005年 | 2106篇 |
2004年 | 1491篇 |
2003年 | 1495篇 |
2002年 | 1134篇 |
2001年 | 898篇 |
2000年 | 791篇 |
1999年 | 557篇 |
1998年 | 362篇 |
1997年 | 319篇 |
1996年 | 230篇 |
1995年 | 211篇 |
1994年 | 188篇 |
1993年 | 101篇 |
1992年 | 90篇 |
1991年 | 86篇 |
1990年 | 95篇 |
1989年 | 66篇 |
1988年 | 62篇 |
1987年 | 41篇 |
1986年 | 46篇 |
1985年 | 23篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1970年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
机器视觉技术通过视觉采集和分析系统对外界环境进行实时图像采集和处理,得到目标的特征信息,最终实现外部设备的控制.机器视觉技术具有精度高、实时性强、自动化与智能化程度高的优点,已广泛应用于机器人控制、工业生产、辅助医疗诊断等领域.随着医疗技术的发展,机器视觉作为人工智能的重要分支,在康复领域也得到越来越多的应用.本文综述了机器视觉的基本结构和工作原理,并对其在辅助辅具、肢体康复、心理康复等5种康复领域的常见应用进展状况进行简要归纳与介绍,最后总结了机器视觉应用于康复领域的主要问题和发展趋势. 相似文献
992.
目的 使用加权基因共表达网络分析探究糖尿病肾病基因的协同共表达,寻找糖尿病肾病发病的潜在关键基因.方法 从GEO数据库下载GSE30122表达谱数据,根据基因的相关性,构建基因共表达模块,并计算模块基因与疾病的相关性,选取与疾病显著相关的关键模块,使用R包clusterprofiler数据库进行GO与KEGG富集分析,并根据基因log FC值与富集最显著的通路关联并分析.结果 MEturquoise模块与疾病呈显著相关性(P=0.02);利用limma包筛选出的差异表达基因与关键模块中基因取交集,共得到201个共有关键基因,主要富集于细胞黏附分子、糖尿病并发症中的AGE-RAGE信号通路,细胞黏附分子中的CDH3、F11R、VTCN1表达下调,ITGA8、NECTIN2、NTNG1表达上调;AGE-RAGE信号通路中MAPK13表达上调,而COL4A3、PLCE1、PLCG2、VEGFA表达下调.结论 细胞黏附分子中的CDH3、F11R、VTCN1、ITGA8、NECTIN2、NTNG1等基因与AGE-RAGE信号通路中的MAPK13、COL4A3、PLCE1、PLCG2、VEGFA等基因可能在DN的发生发展中起到关键作用. 相似文献
993.
994.
995.
996.
Yan Rong Fei Wang Jing Liu Yang Zhou Xiaoli Li Xinhua Liang Dandan Zhang Huadong Zeng Jing Wang Yi Shi 《Journal of medical virology》2021,93(1):448-455
This study investigates the clinical and imaging characteristics of coronavirus disease 2019 (COVID‐19) patients with false‐negative nucleic acids. Mild‐to‐moderate COVID‐19 patients, including 19 cases of nucleic acid false‐negative patients and 31 cases of nucleic acid positive patients, were enrolled. Their epidemiological, clinical, and laboratory examination data and imaging characteristics were analyzed. Risk factors for false negatives were discussed. Compared with the nucleic acid positive group, the false‐negative group had less epidemiological exposure (52.6% vs 83.9%; P = .025), less chest discomfort (5.3% vs 32.3%; P = .035), and faster recovery (10 [8, 13] vs 15 [11, 18.5] days; P = .005). The number of involved lung lobes was (2 [1, 2.5] vs 3 [2, 4] days; P = .004), and the lung damage severity score was (3 [2.5, 4.5] vs 5 [4, 9] days; P = .007), which was lighter in the nucleic acid false‐negative group. Thus, the absence of epidemiological exposure may be a potential risk factor for false‐negative nucleic acids. The false‐negative cases of COVID‐19 are worth noting because they have a risk of viral transmission without positive test results, lighter clinical manifestations, and less history of epidemiological exposure. 相似文献
997.
Jiping Zhao Jintao Zhang Shuangmei Tang Junfei Wang Tian Liu Rong Zeng Weichun Zhu Kangda Zhang Jinxiang Wu 《Immunobiology》2021,226(5):152124
Asthma is a chronic respiratory disease characterized by airway inflammation and remodeling as well as hyper-responsiveness. Thymic stromal lymphopoietin (TSLP), which is a crucial inflammatory cytokine in immune homeostasis, consists of two isoforms, the long isoform lfTSLP and short isoform sfTSLP. The lfTSLP promotes inflammation and plays a pivotal role in asthma pathogenesis, while sfTSLP had been reported to have anti-asthma effects. Experiments have shown that lfTSLP could induce autophagy in hepatocytes. It is unknown whether lfTSLP or sfTSLP could influence autophagy and affect the progression of asthma. Using house dust mite (HDM)-stimulated airway smooth muscle cells as an in vitro model and HDM-induced asthma mice as in vivo model, we found that lfTSLP could induce autophagy and remodeling, while sfTSLP has the reverse effect. Strikingly, sfTSLP treatment in vivo reversed HDM-mediated activation of inflammation and airway remodeling, partly determined by autophagy change. These findings may help us understand the function of TSLP isoforms in the pathogenesis of asthma, and they support the use of drugs targeting sfTSLP and TSLP for asthma treatment. 相似文献
998.
Tae Young Shin Mi Rong Lee Se Jin Lee Jong Cheol Kim Sihyeon Kim So Eun Park Woo Jin Kim Jae Su Kim 《Journal of basic microbiology》2021,61(7):642-651
The species of Beauveria bassiana is widely used for the management of agricultural insect pests. In this study, we integrated egfp-double-stranded RNA (dsRNA) to a previously generated egfp-expressing B. bassiana transformant (Bb-egfp#3) using a protoplast integration method. The Bb-egfp#3 protoplast was mixed with the dsRNA under PEG/CaCl2 conditions and liquid-cultured in Sabouraud dextrose broth for 5 days. A control culture followed the same procedure without dsRNA. Bb-egfp#3/egfp-dsRNA cultures showed very low fungal growth (OD630 = 0.2) compared to the control culture, Bb-egfp#3 only (OD630 = 1.1). Screening of possible transformants on Sabouraud dextrose agar revealed a transformant T3, without egfp signal. T3 was confirmed as B. bassiana through sequencing of conserved genes and insect bioassays. Interestingly, the genomic egfp fragment of T3 was disrupted, and the egfp signal was not detected over four subcultures, which was also confirmed by RNA-seq of Bb-egfp#3 and T3. This study provides an interesting observation that protoplast integration with dsRNA could possibly generate significantly reduced gene expression in B. bassiana and it is stable across several generations. 相似文献
999.
Li Yu-Yang Cai Qing Li Bao-Sheng Qiao Shu-Wei Jiang Jia-Yang Wang Dan Du Xue-Chun Meng Wei-Yan 《Inflammation》2021,44(3):846-858
Inflammation - Periodontitis is a chronic inflammatory disease induced by Porphyromonas gingivalis (P. gingivalis) and other pathogens. P. gingivalis release various virulence factors including... 相似文献
1000.
Haiyan Zhu Yian Tian Huaiping Cheng Yafei Zheng Wei Wang Tianping Bao Rong Wu Zhaofang Tian 《International journal of medical sciences》2021,18(12):2581
Objective: The study was designed to investigate some plasma markers which help us to decide the use of adjuvant corticosteroid therapy in bronchopulmonary dysplasia (BPD) of premature infants.Methods: Thirty BPD infants were treated by dexamethasone. Among these cases, dexamethasone was significant effective in 10 cases, and no significant effective in 20 cases. These patients were divided into two groups as the significant effect (SE) group (n=10) and the non-significant effect (NE) group (n=20) according to the curative effect of dexamethasone. Fifteen non-BPD infants with gestational age and gender matching were selected as the control group. Plasma samples before and after dexamethasone treatment were collected from three infants chosen randomly from SEG for the data-independent acquisition (DIA) analysis. ELISA was further used to detect the levels of differential proteins LRP1 and S100A8 in all individuals, including SE, NE and control groups.Results: DIA analysis results showed that after dexamethasone treatment, there were a total of 52 plasma proteins that showed significant differences, of which 43 proteins were down-regulated and 9 proteins were up-regulated. LRP1 and S100A8 were two plasma proteins that were significantly changed after dexamethasone treatment. Compared with the control group, plasma LRP1 was significantly increased in BPD. Interestingly, the plasma concentration of LRP1 in the NE group was significantly higher than that in the SE group. S100A8, as an indicator of plasma inflammation, was significantly higher in BPD than the control group. Unlike LRP1, there was no significantly difference between the SE and NE group (P=0.279) before dexamethasone treatment.Conclusion: Elevated plasma LRP1 and S100A8 in BPD infants are two indicators that correlated with the efficacy of dexamethasone, and might be used as biomarkers for deciding the use of adjuvant corticosteroids therapy in the BPD. 相似文献