全文获取类型
收费全文 | 43638篇 |
免费 | 2528篇 |
国内免费 | 466篇 |
专业分类
耳鼻咽喉 | 766篇 |
儿科学 | 807篇 |
妇产科学 | 910篇 |
基础医学 | 6161篇 |
口腔科学 | 759篇 |
临床医学 | 3724篇 |
内科学 | 9343篇 |
皮肤病学 | 1074篇 |
神经病学 | 2992篇 |
特种医学 | 2026篇 |
外国民族医学 | 2篇 |
外科学 | 5990篇 |
综合类 | 734篇 |
一般理论 | 35篇 |
预防医学 | 2416篇 |
眼科学 | 1274篇 |
药学 | 3495篇 |
12篇 | |
中国医学 | 351篇 |
肿瘤学 | 3761篇 |
出版年
2023年 | 293篇 |
2022年 | 657篇 |
2021年 | 1185篇 |
2020年 | 625篇 |
2019年 | 1033篇 |
2018年 | 1141篇 |
2017年 | 814篇 |
2016年 | 1047篇 |
2015年 | 1419篇 |
2014年 | 1721篇 |
2013年 | 2059篇 |
2012年 | 3002篇 |
2011年 | 3114篇 |
2010年 | 1918篇 |
2009年 | 1670篇 |
2008年 | 2398篇 |
2007年 | 2370篇 |
2006年 | 2152篇 |
2005年 | 2136篇 |
2004年 | 1852篇 |
2003年 | 1744篇 |
2002年 | 1645篇 |
2001年 | 1022篇 |
2000年 | 967篇 |
1999年 | 872篇 |
1998年 | 383篇 |
1997年 | 346篇 |
1996年 | 299篇 |
1995年 | 267篇 |
1994年 | 245篇 |
1993年 | 189篇 |
1992年 | 489篇 |
1991年 | 385篇 |
1990年 | 424篇 |
1989年 | 430篇 |
1988年 | 388篇 |
1987年 | 345篇 |
1986年 | 308篇 |
1985年 | 304篇 |
1984年 | 264篇 |
1983年 | 233篇 |
1982年 | 163篇 |
1981年 | 161篇 |
1980年 | 151篇 |
1979年 | 233篇 |
1978年 | 189篇 |
1977年 | 132篇 |
1976年 | 123篇 |
1975年 | 135篇 |
1974年 | 133篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Richard Cartledge Grzegorz Suwalski Anna Witkowska Gary Gottlieb Anthony Cioci Gilbert Chidiac Burak Ilsin Barry Merrill Piotr Suwalski 《Interactive Cardiovascular and Thoracic Surgery》2022,34(4):548
Open in a separate window OBJECTIVESMost strokes associated with atrial fibrillation (AF) result from left atrial appendage thrombi. Oral anticoagulation can reduce stroke risk but is limited by complication risk and non-compliance. Left atrial appendage exclusion (LAAE) is a new surgical option to reduce stroke risk in AF. The study objective was to evaluate the safety and feasibility of standalone thoracoscopic LAAE in high stroke risk AF patients.METHODSThis was a retrospective, multicentre study of high stroke risk AF patients who had oral anticoagulation contraindications and were not candidates for ablation nor other cardiac surgery. Standalone thoracoscopic LAAE was performed using 3 unilateral ports access and epicardial clip. Periprocedural adverse events, long-term observational clinical outcomes and stroke rate were evaluated.RESULTSProcedural success was 99.4% (174/175 patients). Pleural effusion occurred in 4 (2.3%) patients; other periprocedural complications were <1% each. One perioperative haemorrhagic stroke occurred (0.6%). No phrenic nerve palsy or cardiac tamponade occurred. Predicted annual ischaemic stroke rate of 4.8/100 patient-years (based on median CHA2DS2-VASc score of 4.0) was significantly higher than stroke risk observed in follow-up after LAAE. No ischaemic strokes occurred (median follow-up: 12.5 months), resulting in observed rate of 0 (95% CI 0–2.0)/100 patient-years (P < 0.001 versus predicted). Six all-cause (non-device-related) deaths occurred during follow-up.CONCLUSIONSStudy proved that a new surgical option, standalone thoracoscopic LAAE, is feasible and safe. With this method, long-term stroke rate may be reduced compared to predicted for high-risk AF population. 相似文献
982.
Jae Yong Han Yong Joon Kim Eun Young Choi Junwon Lee Ji Hwan Lee Min Kim Suk Ho Byeon Sung Soo Kim Christopher Seungkyu Lee 《Yonsei medical journal》2022,63(4):365
PurposeTo evaluate the therapeutic effects and safety of oral spironolactone (SPRL) in patients with central serous chorioretinopathy (CSC).Materials and MethodsThe medical records and imaging data of patients diagnosed with CSC and treated with SPRL were retrospectively reviewed. Central macular thickness (CMT), subretinal fluid (SRF) height, subfoveal choroidal thickness (SFCT), and best-corrected visual acuity (BCVA) at baseline, at 1, 3, and 6 months, and at the last visit after the treatment were analyzed.ResultsIn total, 103 patients with 107 eyes were included. The mean age of the patients was 51.5±9.3 years, and 77 (72.0%) were male. The mean follow-up duration was 48.6±40.2 weeks. The mean duration of oral SPRL therapy was 15.5±13.4 weeks. CMT, SRF height, and SFCT improved significantly at 1, 3, and 6 months after SPRL therapy and at the last follow-up. BCVA, however, showed no significant change at any time point. The rate of complete resolution of SRF at 1 month was higher in those with chronic CSC than in those with acute CSC (21.1% vs. 6.0%, respectively). Recurrence occurred in 14 (13.1%) eyes after the complete resolution of SRF. Older age (p=0.001), a greater number of previous intravitreal bevacizumab injections (p=0.006), and poor initial visual acuity (p=0.048) were associated with recurrence. No permanent adverse effects were observed.ConclusionOral SPRL showed therapeutic benefits in patients with CSC in terms of SRF resolution, but relatively frequent recurrence was observed, especially in older patients. 相似文献
983.
Wei Chang Colin Tan Sanjna Nilesh Nerurkar Hai Yun Cai Harry Ho Man Ng Duoduo Wu Yu Ting Felicia Wee Jeffrey Chun Tatt Lim Joe Yeong Tony Kiat Hon Lim 《癌症》2021,40(9):367-387
常规免疫组织化学(immunohistochemistry,IHC)是组织病理学中广泛应用的诊断技术.但该技术存在诸多局限性,包括观察者间的变异性高,每张组织切片仅能标记一个标志物.本文详细描述了各种多重检测技术,这些技术克服了上述局限性,可在单张切片上同时检测多个标志物,可对细胞组成、细胞功能和细胞间相互作用进行整合... 相似文献
984.
Diana H. Taft Zachery T. Lewis Nhu Nguyen Steve Ho Chad Masarweh Vanessa Dunne-Castagna Daniel J. Tancredi M. Nazmul Huda Charles B. Stephensen Katie Hinde Erika von Mutius Pirkka V. Kirjavainen Jean-Charles Dalphin Roger Lauener Josef Riedler Jennifer T. Smilowitz J. Bruce German Ardythe L. Morrow David A. Mills 《Nutrients》2022,14(7)
Bifidobacterium species are beneficial and dominant members of the breastfed infant gut microbiome; however, their health benefits are partially species-dependent. Here, we characterize the species and subspecies of Bifidobacterium in breastfed infants around the world to consider the potential impact of a historic dietary shift on the disappearance of B. longum subsp. infantis in some populations. Across populations, three distinct patterns of Bifidobacterium colonization emerged: (1) The dominance of Bifidobacterium longum subspecies infantis, (2) prevalent Bifidobacterium of multiple species, and (3) the frequent absence of any Bifidobacterium. These patterns appear related to a country’s history of breastfeeding, with infants in countries with historically high rates of long-duration breastfeeding more likely to be colonized by B. longum subspecies infantis compared with infants in countries with histories of shorter-duration breastfeeding. In addition, the timing of infant colonization with B. longum subsp. infantis is consistent with horizontal transmission of this subspecies, rather than the vertical transmission previously reported for other Bifidobacterium species. These findings highlight the need to consider historical and cultural influences on the prevalence of gut commensals and the need to understand epidemiological transmission patterns of Bifidobacterium and other major commensals. 相似文献
985.
Piia Jul Tran T. Ho Urve Kallavus Alar Konist Kristiina Leiman Olivia-Stella Salm Maria Kulp Mihkel Koel Tiit Lukk 《Materials》2022,15(8)
The production of novel materials and value-added chemicals from lignin has received considerable attention in recent years. Due to its abundant occurrence in nature, there is a growing interest in utilizing lignin as a feedstock for functional materials production, for example aerogels. Much like in the synthesis of phenol-based resins, the vacant ortho positions of the aromatic rings in lignin can crosslink with formaldehyde and form polymeric gels. After drying the hydrogels with supercritical CO2, highly porous aerogels are obtained. Current study focuses on the preparation and thorough parametrization of organosolv lignins from different types of lignocellulosic biomass (aspen, pine, and barley straw) as well as their utilization for the preparation of lignin-5-methylresorcinol-formaldehyde aerogels. The thorough structural characterization of the obtained aerogels was carried out by gas adsorption, IR spectroscopy, and scanning electron microscopy. The obtained lignin-based monolithic mesoporous aerogels had specific surface areas and total pore volumes in the upward ranges of 450 m2/g and 1.4 cm3/g, respectively. 相似文献
986.
987.
An unusual variant of familial preexcitation 总被引:4,自引:0,他引:4
988.
Immunological screening method to detect specific translation products. 总被引:23,自引:24,他引:23
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
S Broome W Gilbert 《Proceedings of the National Academy of Sciences of the United States of America》1978,75(6):2746-2749
We describe a very sensitive method to detect as antigens the presence of specific proteins within phage plaques or bacterial colonies. We coat plastic sheets with antibody molecules, expose the sheet to lysed bacteria so that a released antigen can bind, and then label the immobilized antigen with radioiodinated antibodies. Thus, the antigen is sandwiched between the antibodies attached to the plastic sheet and those carrying the radioactive label. Autoradiography then shows the positions of antigen-containing colonies or phage plaques. A few molecules of antigen released from each bacterial cell generatean adequate signal. 相似文献
989.
990.
Zhang Y Yang W Mok CC Chan TM Wong RW Mok MY Lee KW Wong SN Leung AM Lee TL Ho MH Lee PP Wong WH Yang J Zhang J Wong CM Ng IO Garcia-Barceló MM Cherny SS Tam PK Sham PC Lau CS Lau YL 《Genes and immunity》2011,12(3):231-234
UHRF1BP1 encodes a highly conserved protein with unknown function. Previously, a coding variant in this gene was found to be associated with systemic lupus erythematosus (SLE) in populations of European ancestry (rs11755393, R454Q, P=2.22 x 10??, odds ratio=1.17). In this study, by a combination of genome-wide study and replication involving a total of 1230 patients and 3144 controls, we confirmed the association of this coding variant to SLE in Hong Kong Chinese. We also identified another coding variant in this gene that independently contributes to SLE susceptibility (rs13205210, M1098T, P=4.44 x 10??, odds ratio=1.49). Cross-population confirmation establishes the involvement of this locus in SLE and indicates that distinct alleles are contributing to disease susceptibility. 相似文献