全文获取类型
收费全文 | 19003篇 |
免费 | 1468篇 |
国内免费 | 445篇 |
专业分类
耳鼻咽喉 | 117篇 |
儿科学 | 412篇 |
妇产科学 | 248篇 |
基础医学 | 1116篇 |
口腔科学 | 444篇 |
临床医学 | 2702篇 |
内科学 | 1730篇 |
皮肤病学 | 296篇 |
神经病学 | 1449篇 |
特种医学 | 339篇 |
外科学 | 1244篇 |
综合类 | 2781篇 |
一般理论 | 7篇 |
预防医学 | 4404篇 |
眼科学 | 369篇 |
药学 | 1629篇 |
37篇 | |
中国医学 | 1101篇 |
肿瘤学 | 491篇 |
出版年
2024年 | 34篇 |
2023年 | 326篇 |
2022年 | 615篇 |
2021年 | 801篇 |
2020年 | 807篇 |
2019年 | 834篇 |
2018年 | 777篇 |
2017年 | 765篇 |
2016年 | 736篇 |
2015年 | 651篇 |
2014年 | 1211篇 |
2013年 | 1586篇 |
2012年 | 1056篇 |
2011年 | 1215篇 |
2010年 | 864篇 |
2009年 | 825篇 |
2008年 | 923篇 |
2007年 | 895篇 |
2006年 | 749篇 |
2005年 | 595篇 |
2004年 | 540篇 |
2003年 | 471篇 |
2002年 | 407篇 |
2001年 | 359篇 |
2000年 | 292篇 |
1999年 | 272篇 |
1998年 | 217篇 |
1997年 | 204篇 |
1996年 | 158篇 |
1995年 | 161篇 |
1994年 | 155篇 |
1993年 | 118篇 |
1992年 | 126篇 |
1991年 | 129篇 |
1990年 | 108篇 |
1989年 | 113篇 |
1988年 | 88篇 |
1987年 | 80篇 |
1986年 | 107篇 |
1985年 | 65篇 |
1984年 | 73篇 |
1983年 | 65篇 |
1982年 | 73篇 |
1981年 | 58篇 |
1980年 | 54篇 |
1979年 | 52篇 |
1978年 | 27篇 |
1977年 | 16篇 |
1976年 | 23篇 |
1975年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Medical Journal Armed Forces India》2022,78(1):7-16
Oocyte and embryo grading is one of the most important steps in assisted reproductive technology to identify the best among cultured embryos for transfer or vitrification. The most commonly used non-invasive method is morphological assessment of gametes and embryos using a microscope. This method despite being simple and cost-effective has interobserver and intraobserver variability and subjectivity and has little to offer about the physiological state of embryos. This review sourced research articles and reviews pertaining to other non-invasive assessment methodologies from Medline and PubMed to collate latest technologies in vogue and identify novel methodologies of the future. The review assesses the current understanding in oocyte and embryo grading and touches upon novel non-invasive techniques and potential biomarkers to identify the best embryo. The latest available literature on time-lapse imaging, hierarchical algorithms, omics (consisting of proteomics and secretomes), miRNAs, mitochondrial RNAs and artificial intelligence has been accessed to summarize the enormous information available, to identify gaps in current interpretations, to identify emerging technologies and to provide direction for future research. This review will greatly benefit anyone practicing assisted reproduction and clinical embryology. 相似文献
2.
通过对中医古籍中有关升降散论述的文献梳理,全面探讨其内涵。本方是在大黄、僵蚕为雏形的基础上增加蝉蜕、姜黄而成方,几经易名,终在杨璿《伤寒瘟疫条辨》中为后人所熟知。本方广泛用于治疗瘟疫,以丸剂、散剂为主,方便携带,便于服用;重用大黄旨在祛邪、逐秽;应用时视人之体质强弱和量其毒之轻重而判断用药多寡,并辅以米酒、生蜜等以顾护正气。杨璿将其由治疗“热疫”的专方扩展为治疗“表里三焦大热”的通用方剂,扩大了本方治疗疾病范围。 相似文献
3.
《The ocular surface》2020,18(1):108-113
PurposeAromatase inhibitors (AIs) limit the synthesis of oestrogen in peripheral tissues thus lowering levels of oestrogen. The primary aim was to evaluate whether women treated with AIs have altered dry eye symptoms and signs. A sub-aim was to investigate whether symptoms of dry eye in postmenopausal women were associated with symptoms of non-eye pain, ocular pain and self-rated pain perception.MethodsThis cross-sectional, observational, single visit study recruited 56 postmenopausal women (mean age 64.1 + 7.9 years) and 52 undergoing AI treatment (mean age 66.6 + 9.0). Ocular symptoms (OSDI, MGD14) and pain questionnaires (PSQ, OPAS) were administered and signs of dry eye and meibomian gland dysfunction were evaluated.ResultsAlmost half of each group reported dry eye symptoms, defined as OSDI>12 (48% control, 46% AI). The PSQ score was significantly higher in the AI group (p = 0.04). Neither frequency or severity of dry eye (or MGD) symptoms scores were significantly different between groups. In the AI group, meibomian gland expressibility score was worse (p = 0.003); there were no differences in any other signs. Higher OSDI scores were associated with higher OPAS eye-pain scores (r = 0.49, p < 0.001), but not OPAS non-eye pain (r = 0.09, p = 0.35). Pain perception (PSQ) showed a moderate positive association with OPAS eye-pain (r = 0.30, p = 0.003).ConclusionsIn this study elevated ocular symptoms were observed in both the AI treated and the untreated groups, with no difference between the groups. Women undergoing AI treatment for early stage breast cancer had worse meibum expressibility score and increased pain perception compared to an untreated group of women. 相似文献
4.
5.
【目的】 值此《中国科技期刊研究》创刊30周年之际,思考科研评价体系的改变给中文科技期刊带来的影响,为中文期刊探寻发展路径。【方法】 结合对中文科技期刊困境的研究,提出应对策略。【结果】 近期国家陆续出台的纠偏评价导向的政策文件,为中文科技期刊既带来了发展机遇,也提出了挑战。【结论】 在重构符合中文科技期刊发展特点的评价体系的基础上,中文科技期刊应明确目标定位,面向国家需求,提升知识服务能力,建立品牌特色。 相似文献
6.
7.
8.
Moises Rodriguez-Gonzalez Antonio Moruno Tirado Reza Hosseinpour Jose Santos de Soto 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》2015,42(4):350-356
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic. 相似文献
9.
10.