全文获取类型
收费全文 | 1947771篇 |
免费 | 149882篇 |
国内免费 | 26193篇 |
专业分类
耳鼻咽喉 | 26382篇 |
儿科学 | 53355篇 |
妇产科学 | 52470篇 |
基础医学 | 270765篇 |
口腔科学 | 52401篇 |
临床医学 | 183687篇 |
内科学 | 368254篇 |
皮肤病学 | 36801篇 |
神经病学 | 149069篇 |
特种医学 | 77766篇 |
外国民族医学 | 703篇 |
外科学 | 288429篇 |
综合类 | 89226篇 |
现状与发展 | 78篇 |
一般理论 | 512篇 |
预防医学 | 142245篇 |
眼科学 | 47409篇 |
药学 | 151162篇 |
334篇 | |
中国医学 | 20402篇 |
肿瘤学 | 112396篇 |
出版年
2022年 | 16937篇 |
2021年 | 26208篇 |
2020年 | 18304篇 |
2019年 | 21384篇 |
2018年 | 26258篇 |
2017年 | 21648篇 |
2016年 | 22259篇 |
2015年 | 29171篇 |
2014年 | 39142篇 |
2013年 | 48516篇 |
2012年 | 67008篇 |
2011年 | 72671篇 |
2010年 | 43898篇 |
2009年 | 38847篇 |
2008年 | 61792篇 |
2007年 | 65296篇 |
2006年 | 65398篇 |
2005年 | 64490篇 |
2004年 | 56982篇 |
2003年 | 54649篇 |
2002年 | 52088篇 |
2001年 | 77175篇 |
2000年 | 79891篇 |
1999年 | 69959篇 |
1998年 | 23125篇 |
1997年 | 21769篇 |
1996年 | 20412篇 |
1995年 | 19097篇 |
1994年 | 17743篇 |
1992年 | 52970篇 |
1991年 | 51008篇 |
1990年 | 49807篇 |
1989年 | 47814篇 |
1988年 | 44472篇 |
1987年 | 43591篇 |
1986年 | 41570篇 |
1985年 | 39738篇 |
1984年 | 30147篇 |
1983年 | 25675篇 |
1979年 | 29200篇 |
1978年 | 20765篇 |
1977年 | 17525篇 |
1976年 | 16357篇 |
1975年 | 17815篇 |
1974年 | 21785篇 |
1973年 | 20840篇 |
1972年 | 19814篇 |
1971年 | 18299篇 |
1970年 | 17559篇 |
1969年 | 16719篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Ahmed M. Abu El-Asrar Ajmal Ahmad Eef Allegaert Mohammad Mairaj Siddiquei Priscilla W. Gikandi Gert De Hertogh 《Ocular immunology and inflammation》2020,28(4):575-588
ABSTRACT
Purpose
To investigate the expression of IL-11 and its receptor IL-11Rα and to quantify density of CD163+ M2 macrophages in proliferative diabetic retinopathy (PDR). 相似文献32.
The present study sought to investigate the association between social phobia symptoms and self‐reported physical symptoms and the moderation effect of resting respiratory sinus arrhythmia (RSA) on this link. Data of 5‐min resting RSA, social phobia symptoms assessed by the Social Phobia Scale, and physical symptoms assessed by the Cohen–Hoberman Inventory of Physical Symptoms were collected from 167 undergraduate students. Results indicated that higher levels of social phobia symptoms were associated with higher levels of self‐reported physical symptoms. Resting RSA played the moderating role in the link between social phobia symptoms and self‐reported physical symptoms, such that social phobia symptoms were positively associated with self‐reported physical symptoms among individuals with low resting RSA, whereas this association was nonsignificant among individuals with high resting RSA. These findings suggest that high resting RSA as a physiological marker of better self‐regulation capacity might buffer the effect of social phobia symptoms on physical health. 相似文献
33.
Peng‐fei Lei Shi‐long Su Ling‐yu Kong Cheng‐gong Wang Da Zhong Yi‐he Hu 《Orthopaedic Surgery》2019,11(5):914-920
Three‐dimensional (3D) printing technology, virtual reality, and augmented reality technology have been used to help surgeons to complete complex total hip arthroplasty, while their respective shortcomings limit their further application. With the development of technology, mixed reality (MR) technology has been applied to improve the success rate of complicated hip arthroplasty because of its unique advantages. We presented a case of a 59‐year‐old man with an intertrochanteric fracture in the left femur, who had received a prior left hip fusion. After admission to our hospital, a left total hip arthroplasty was performed on the patient using a combination of MR technology and 3D printing technology. Before surgery, 3D reconstruction of a certain bony landmark exposed in the surgical area was first performed. Then a veneer part was designed according to the bony landmark and connected to a reference registration landmark outside the body through a connecting rod. After that, the series of parts were made into a holistic reference registration instrument using 3D printing technology, and the patient's data for bone and surrounding tissue, along with digital 3D information of the reference registration instrument, were imported into the head‐mounted display (HMD). During the operation, the disinfected reference registration instrument was installed on the selected bony landmark, and then the automatic real‐time registration was realized by HMD through recognizing the registration landmark on the reference registration instrument, whereby the patient's virtual bone and other anatomical structures were quickly and accurately superimposed on the real body of the patient. To the best of our knowledge, this is the first report to use MR combined with 3D printing technology in total hip arthroplasty. 相似文献
34.
35.
36.
37.
Benyam Kinde Harrison W. Gabel Caitlin S. Gilbert Eric C. Griffith Michael E. Greenberg 《Proceedings of the National Academy of Sciences of the United States of America》2015,112(22):6800-6806
DNA methylation at CpG dinucleotides is an important epigenetic regulator common to virtually all mammalian cell types, but recent evidence indicates that during early postnatal development neuronal genomes also accumulate uniquely high levels of two alternative forms of methylation, non-CpG methylation and hydroxymethylation. Here we discuss the distinct landscape of DNA methylation in neurons, how it is established, and how it might affect the binding and function of protein readers of DNA methylation. We review studies of one critical reader of DNA methylation in the brain, the Rett syndrome protein methyl CpG-binding protein 2 (MeCP2), and discuss how differential binding affinity of MeCP2 for non-CpG and hydroxymethylation may affect the function of this methyl-binding protein in the nervous system. 相似文献
38.
Dynamic LVOT Obstruction and Aortic Stenosis in the Same Patient: A Case of Challenging Doppler Hemodynamics 下载免费PDF全文
Matthew W. Parker M.D. Francis J. Kiernan M.D. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(6):1030-1032
We present a patient with both dynamic left ventricular outflow tract obstruction and valvular aortic stenosis. The aortic valve was calcified, and velocities and gradients measured by continuous‐wave Doppler met standard criteria for severe aortic stenosis. The increased subvalvular velocities invalidated assumptions of the simplified Bernoulli equation; correction using the longer form of the Bernoulli equation suggested a lower but still significant gradient. The complex shape of the subvalvular spectral Doppler envelope indicated supranormal systolic function and dynamic left ventricular outflow obstruction. Left heart catheterization with an end‐hole catheter was required to determine the subvalvular and valvular components of the obstruction. 相似文献
39.
F. Fruzzetti G. Palla A. Sbrana T. Simoncini M. R. Sessa 《Gynecological endocrinology》2020,36(10):938-940
AbstractObjective: To understand the origin of extremely high gonadotropin levels in a perimenopausal woman.Methods: A 52-year-old woman with a 2?months of amenorrhea followed spontaneous menstrual cycles recovery was referred to our outpatient clinic with elevated follicle-stimulating hormone (FSH, 483 mUI/ml), luteinizing hormone (LH, 475 mUI/ml) and prolactin (PRL, 173?ng/ml). She was known to take levosulpiride. The gonadotropin levels did not fit with the clinical features.Results: A gonadotroph tumor was ruled out. Further analysis confirmed constantly high FSH, LH and PRL levels. The measurements were repeated using different analytical platforms with different results. After serial dilutions, nonlinearity was present suggesting an immunoassay interference. After post-polyethylene glycol recovery, hormone levels appeared in the normal range. Anti-goat antibodies were recognized in the serum of the patient.Conclusions: This case report shows a case of falsely abnormal high gonadotropin and PRL levels in a woman during menopause transition. In the clinical practice the evaluation of gonadotropin profile is not recommended at this age, but the abnormal levels stimulated further evaluation. An interference in the assay due to anti-goat antibodies resulted in abnormally high level of FSH and LH. A strict collaboration between clinicians and the laboratory is needed, when laboratory findings do not correspond to clinical findings. 相似文献
40.