全文获取类型
收费全文 | 15877篇 |
免费 | 1334篇 |
国内免费 | 1219篇 |
专业分类
耳鼻咽喉 | 106篇 |
儿科学 | 185篇 |
妇产科学 | 230篇 |
基础医学 | 1909篇 |
口腔科学 | 343篇 |
临床医学 | 2280篇 |
内科学 | 2561篇 |
皮肤病学 | 124篇 |
神经病学 | 859篇 |
特种医学 | 808篇 |
外国民族医学 | 11篇 |
外科学 | 1694篇 |
综合类 | 2397篇 |
现状与发展 | 3篇 |
一般理论 | 3篇 |
预防医学 | 871篇 |
眼科学 | 364篇 |
药学 | 1564篇 |
12篇 | |
中国医学 | 806篇 |
肿瘤学 | 1300篇 |
出版年
2024年 | 50篇 |
2023年 | 259篇 |
2022年 | 657篇 |
2021年 | 864篇 |
2020年 | 577篇 |
2019年 | 521篇 |
2018年 | 562篇 |
2017年 | 443篇 |
2016年 | 455篇 |
2015年 | 680篇 |
2014年 | 864篇 |
2013年 | 714篇 |
2012年 | 1093篇 |
2011年 | 1215篇 |
2010年 | 712篇 |
2009年 | 660篇 |
2008年 | 795篇 |
2007年 | 783篇 |
2006年 | 748篇 |
2005年 | 774篇 |
2004年 | 493篇 |
2003年 | 501篇 |
2002年 | 441篇 |
2001年 | 345篇 |
2000年 | 392篇 |
1999年 | 453篇 |
1998年 | 305篇 |
1997年 | 289篇 |
1996年 | 242篇 |
1995年 | 242篇 |
1994年 | 167篇 |
1993年 | 129篇 |
1992年 | 143篇 |
1991年 | 103篇 |
1990年 | 95篇 |
1989年 | 89篇 |
1988年 | 84篇 |
1987年 | 96篇 |
1986年 | 71篇 |
1985年 | 70篇 |
1984年 | 34篇 |
1983年 | 25篇 |
1982年 | 23篇 |
1981年 | 22篇 |
1980年 | 28篇 |
1979年 | 13篇 |
1978年 | 15篇 |
1977年 | 25篇 |
1976年 | 12篇 |
1975年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
A role for hyaluronan in macrophage accumulation and collagen deposition after bleomycin-induced lung injury 总被引:6,自引:0,他引:6
Savani RC Hou G Liu P Wang C Simons E Grimm PC Stern R Greenberg AH DeLisser HM Khalil N 《American journal of respiratory cell and molecular biology》2000,23(4):475-484
Elevated concentrations of hyaluronan (HA) are associated with the accumulation of macrophages in the lung after injury. We have investigated the role of HA in the inflammatory and fibrotic responses to lung injury using the intratracheal instillation of bleomycin in rats as a model. After bleomycin-induced lung injury, both HA content in bronchoalveolar lavage (BAL) and staining for HA in macrophages accumulating in injured areas of the lung were maximal at 4 d. Increased HA in BAL correlated with increased locomotion of isolated alveolar macrophages. HA-binding peptide was able to specifically block macrophage motility in vitro. Importantly, systemic administration of HA-binding peptide to rats before injury not only decreased alveolar macrophage motility and accumulation in the lung, but also reduced lung collagen alpha (I) messenger RNA and hydroxyproline contents. We propose a model in which HA plays a critical role in the inflammatory response and fibrotic consequences of acute lung injury. 相似文献
62.
In this article, we proposed a multifunctional telemedicine system supporting both telediagnosis and teleconsultation services. We attempted not only to insure that the implementation of this system satisfied most requirements, but also to evaluate the impact of the system. With regard to system architecture, we designed a unified multimedia database to store all types of data and used two kinds of network (ATM and ISDN) for different possible applications. As for data transmission, the REFRESH and PREFETCH mechanisms were implemented to enhance data transfer efficiency. A total of 1107 consultations employing the telemedicine system were performed during the past 3 years. This technology was used most frequently for radiology consultation (32.7%, n = 362) and ultrasonic examination (19.5%, n = 216). An evaluation of the impact on diagnosis (507 valid cases) indicated that the diagnosis in 80 cases (15.78%) were altered on the basis of second opinions from a medical center; and the number of patients transferred to the medical center was reduced from 24 (4.7%) to eight cases. Most of the rural-site physicians (97%) thought that they did benefit from specialists' experience and knowledge via the telemedicine system. Based on 431 valid questionnaires, the number of the patients with confidence in the telemedicine system at their local healthcare center increased from 72.6% to 87.5%. Overall, more than 90% of patients and physicians believed that the system was valuable and provided satisfactory services. 相似文献
63.
Russell EJ; Geremia GK; Johnson CE; Huckman MS; Ramsey RG; Washburn-Bleck J; Turner DA; Norusis M 《Radiology》1987,165(3):609-617
Sixteen patients with suspected cerebral metastases were studied with magnetic resonance (MR) imaging before and after the intravenous administration of 0.1 mmol/kg of gadolinium diethylenetriaminepenta-acetic acid. The images were interpreted blindly by two neuroradiologists; all clinical, radiologic (computed tomographic and MR imaging), and pathologic data were reviewed to arrive at a final "best diagnosis," which was then compared with the prior blinded interpretations. Of seven patients found to have multiple metastases, six (86%) had at least one tumor nodule depicted by postinfusion MR imaging that was missed by one or both observers on review of preinfusion images alone. Lesions missed on preinfusion studies were usually small nodules hidden by or not detected next to regions of high-signal edema thought to be related to the adjacent tumor nodule. The authors believe that contrast enhancement improves detection of metastatic foci with MR imaging and that the findings indicate broader implications for the detection of multiple lesions from other causes. 相似文献
64.
Anthony Xiang Wei Hou Sina Rashidian Richard N Rosenthal Kayley Abell-Hart Xia Zhao Fusheng Wang 《JMIR Public Health and Surveillance》2021,7(4)
BackgroundOpioid overdose-related deaths have increased dramatically in recent years. Combating the opioid epidemic requires better understanding of the epidemiology of opioid poisoning (OP) and opioid use disorder (OUD).ObjectiveWe aimed to discover geospatial patterns in nonmedical opioid use and its correlations with demographic features related to despair and economic hardship, most notably the US presidential voting patterns in 2016 at census tract level in New York State.MethodsThis cross-sectional analysis used data from New York Statewide Planning and Research Cooperative System claims data and the presidential voting results of 2016 in New York State from the Harvard Election Data Archive. We included 63,958 patients who had at least one OUD diagnosis between 2010 and 2016 and 36,004 patients with at least one OP diagnosis between 2012 and 2016. Geospatial mappings were created to compare areas of New York in OUD rates and presidential voting patterns. A multiple regression model examines the extent that certain factors explain OUD rate variation.ResultsSeveral areas shared similar patterns of OUD rates and Republican vote: census tracts in western New York, central New York, and Suffolk County. The correlation between OUD rates and the Republican vote was .38 (P<.001). The regression model with census tract level of demographic and socioeconomic factors explains 30% of the variance in OUD rates, with disability and Republican vote as the most significant predictors.ConclusionsAt the census tract level, OUD rates were positively correlated with Republican support in the 2016 presidential election, disability, unemployment, and unmarried status. Socioeconomic and demographic despair-related features explain a large portion of the association between the Republican vote and OUD. Together, these findings underscore the importance of socioeconomic interventions in combating the opioid epidemic. 相似文献
65.
目的研究藿香正气片增强镇静催眠药对小鼠的镇静催眠作用.为临床增添了一个中西药结合的镇静催眠合剂提供药理依据.方法应用抖笼换能器法观察藿香正气片对小鼠的自发活动的影响.由此观察藿香正气片与镇静催眠药的协同作用.测定藿香正气片与镇静催眠药对小鼠的入睡时间及睡眠持续时间的作用.两个实验均分成四组,生理水组、藿香正气片组、安定组、安定+藿香正气片组.结果1.对小鼠自发活动的影响.(1)藿香正气片组与生理盐水组比较,具有极显著性差异(P<0.01).(2)安定组与安定+藿香正气片组比较具有显著性差异(P<0.05).2.藿香正气片增强镇静催眠药对小鼠的睡眠作用.(1)藿香正气片组与生理盐水组比较具有显著性差异(P<0.05).(2)藿香正气片+安定组与安定组比较具有极显著性差异(P<0.01).结论藿香正气片与安定合用对镇静及催眠确有协同作用. 相似文献
66.
观察肝硬变患者幽门螺杆菌感染的差异性及其对病情的影响.结果发现随着肝功能的减退,ChildA组,ChildB组,ChildC组HP的感染率逐步升高,CagA、VacA阳性率也逐步升高,ChildC与各组比较HP的感染率,CagA、VacA的阳性率均显著增高,差异有显著性(P<0.05),胃排空无差异(P>0.05).其余各组间比较无差异(P>0.05).提示肝硬变患者与对照组比较HP的感染率及其菌株无显著差异,胃的排空与HP的感染无关,肝脏功能状况与HP感染相关性有待进一步研究. 相似文献
67.
口腔链球丙酮酸氧化酶的克隆和序列分析 总被引:1,自引:0,他引:1
目的 阐明血链球菌产生过氧化氢及其调节的分子机理。方法 根据已知的肺炎链球菌丙酮酸氧化酶基因(spxB)序列设计PCR引物,扩增血链球菌ATCC10557的丙酮酸氧化酶基因,以pUC18及M13mp18、M13mp19为载体进行克隆和亚克隆,并进行序列分析。结果 成功地从血链球菌ATCC10557扩增出丙酮酸氧化酶基因,获得该基因的全部序列(1788bp),具有完整的开放读框,能编码591个氨基酸的多肽。结论 血链球菌丙酮酸氧化酶基因的克隆和序列分析,为进一步研究调节血链球菌产生过氧化氢的分子机理打下了基础。 相似文献
68.
Alfred K. Cheung Tara I. Chang William C. Cushman Susan L. Furth Fan Fan Hou Joachim H. Ix Gregory A. Knoll Paul Muntner Roberto Pecoits-Filho Mark J. Sarnak Sheldon W. Tobe Charles R.V. Tomson Lyubov Lytvyn Jonathan C. Craig David J. Tunnicliffe Martin Howell Marcello Tonelli Michael Cheung Johannes F.E. Mann 《Kidney international》2021,99(3):559-569
69.
Qiu Zhi Guo Quan-bin Ablikim Zakir Shi Xu-wen Hou Jiang-jiang Chen Chang Hasanjan Mamat Akbarjan Mamat Anwar Abdukadir 《International urology and nephrology》2021,53(10):1969-1976
International Urology and Nephrology - This article analyzed the safety and efficacy of ultrasound-guided mini-percutaneous nephrolithotomy (MPCNL) with low-pressure perfusion for the treatment of... 相似文献
70.
Effect of photobiomodulation on CCC-ESF reactive oxygen species steady-state in high glucose mediums
Chen Hongli Tu Mengru Shi Jia Wang Yunhao Hou Zhenhao Wang Jinhai 《Lasers in medical science》2021,36(3):555-562
Lasers in Medical Science - Delayed wound healing is one of the most challenging complications of diabetes mellitus (DM) in clinical medicine, and it is related to the excessive generation of... 相似文献