首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1222篇
  免费   91篇
  国内免费   4篇
耳鼻咽喉   2篇
儿科学   8篇
妇产科学   8篇
基础医学   260篇
口腔科学   42篇
临床医学   107篇
内科学   212篇
皮肤病学   46篇
神经病学   162篇
特种医学   42篇
外科学   164篇
综合类   6篇
预防医学   44篇
眼科学   26篇
药学   102篇
  1篇
肿瘤学   85篇
  2023年   10篇
  2022年   6篇
  2021年   66篇
  2020年   35篇
  2019年   34篇
  2018年   42篇
  2017年   22篇
  2016年   29篇
  2015年   31篇
  2014年   52篇
  2013年   44篇
  2012年   81篇
  2011年   68篇
  2010年   49篇
  2009年   42篇
  2008年   83篇
  2007年   79篇
  2006年   65篇
  2005年   86篇
  2004年   68篇
  2003年   74篇
  2002年   60篇
  2001年   12篇
  2000年   6篇
  1999年   10篇
  1998年   14篇
  1997年   15篇
  1996年   14篇
  1995年   10篇
  1994年   11篇
  1993年   7篇
  1992年   7篇
  1991年   4篇
  1990年   4篇
  1989年   3篇
  1988年   3篇
  1987年   4篇
  1986年   7篇
  1985年   4篇
  1980年   7篇
  1976年   2篇
  1970年   3篇
  1969年   2篇
  1961年   3篇
  1944年   2篇
  1943年   4篇
  1942年   5篇
  1941年   2篇
  1915年   2篇
  1914年   2篇
排序方式: 共有1317条查询结果,搜索用时 171 毫秒
1.
ABSTRACT

Introduction

Individuals with autism spectrum disorder (ASD) and intellectual disability (ID) seem to be at increased risk for post-traumatic stress disorder (PTSD), but knowledge is sparse regarding its identification in this population. Previous research indicates that certain symptoms of PTSD may be more easily recognized, and that identifying reexperiencing and avoidance is particularly challenging.  相似文献   
2.
3.
This essay examines the ‘infiltration’ of eugenics into Russian medical discourse during the formation of the eugenics movement in western Europe and North America in 1900–17. It describes the efforts of two Russian physicians, the bacteriologist and hygienist Nikolai Gamaleia (1859–1949) and the psychiatrist Tikhon Iudin (1879–1949), to introduce eugenics to the Russian medical community, analysing in detail what attracted these representatives of two different medical specialties to eugenic ideas, ideals, and policies advocated by their western colleagues. On the basis of a close examination of the similarities and differences in Gamaleia’s and Iudin’s attitudes to eugenics, the essay argues that lack of cohesiveness gave the early eugenics movement a unique strength. The loose mix of widely varying ideas, ideals, methods, policies, activities and proposals covered by the umbrella of eugenics offered to a variety of educated professionals in Russia and elsewhere the possibility of choosing, adopting and adapting particular elements to their own national, professional, institutional and disciplinary contexts, interests and agendas.  相似文献   
4.
International Journal of Legal Medicine - Sex identification is a primary step in forensic analysis of skeletal remains. The accuracy of sex estimation methods greatly depends on the sexual...  相似文献   
5.
Spinal epidural hematoma. Report of a case and review of the literature   总被引:3,自引:0,他引:3  
We report the case of a thoracic epidural hematoma at the T7-T9 level which occurred after placement of spinal epidural catheter for continuous anaesthesia in acute pancreatitis. The male patient felt a sudden back pain after six days of successful analgesia and became paraplegic 24 hours afterwards. An emergency laminectomy and removal of the hematoma were performed; however, the patient recovered only incompletely.We discuss the clinical signs and symptoms of spinal epidural hematoma as well as its diagnostics and therapy. The controversial views from the literature concernings its etiology are critically reviewed.  相似文献   
6.
Unilateral and bilateral variation in the course and elongation of the cervical (extracranial) part of the internal carotid artery (ICA) leading to its tortuosity, kinking and coiling or looping is not a rare condition, which could be caused by both embryological and acquired factors. Patients with such variations may be asymptomatic in some cases; in others, they can develop cerebrovascular symptoms due to carotid stenosis affecting cerebral circulation. The risk of transient ischemic attacks in patients with carotid stenosis is high and its surgical correction is indicated for the prevention of ischemic stroke. Detection of developmental variations of the ICA and evaluation of its stenotic areas is very important for surgical interventions and involves specific diagnostic imaging techniques for vascular lesions including contrast arteriography, duplex ultrasonography and magnetic resonance angiography. Examination of obtained images in cases of unusual and complicated variations of vascular pattern of the ICA may lead to confusion in interpretation of data. Awareness about details and topographic anatomy of variations of the ICA may serve as a useful guide for both radiologists and vascular surgeons. It may help to prevent diagnostic errors, influence surgical tactics and interventional procedures and avoid complications during the head and neck surgery. Our present study was conducted with a purpose of updating data about developmental variations of the ICA. Dissections of the main neurovascular bundle of the head and neck were performed on a total 14 human adult cadavers (10 – Africans: 7 males & 3 females and 4 – East Indians: all males). Two cases of unilateral congenital elongation of the cervical part of the ICA with kinking and looping and carotid stenoses were found only in African males. Here we present their detailed case reports with review of the literature.  相似文献   
7.
The energy gaps of poly(p-arylenevinylene)s with phenylene, naphthylene and anthrylene subunits are determined by extrapolating the UV/VIS spectroscopic data of the oligomers. The band structure of the three polymers was theoretically investigated. The topology-, geometry- and correlation-factors were determined upon which the energy spectra of this class of one-dimensional π-electron systems depend.  相似文献   
8.
Recent statistical analysis of the folding of G0/G1 chromosomes using fluorescence in situ hybridization (FISH) allowed development of a random walk/giant loop model of chromosome structure. According to this model there are two levels of organization of G0/G1 chromosome fibres. On the first level, the fibres are arranged in giant loops several Mbp in size, and within each loop the fibres are randomly folded. On the second level, the loop attachment sites form a chromosome backbone that also shows random folding. Newly replicated segments of mammalian chromosomes may be directly visualized at high resolution in S-phase nuclei using immunofluorescent methods and appear as worm-like fibres. In our earlier study, we analysed conformation of the fibres in human cells blocked for 16 h at the G1/S boundary with 5- fluorodeoxyuridine (FdU) and then released into S-phase by the addition of a DNA prec ursor. However, long treatment of cells with FdU induces very short replicons and may promote apoptosis. In this study we analysed conformation of the fibres in normally proliferating human cells that had not been blocked with FdU for a long time. It has been found that replicated chromosome fibres visualized just after 2 h of incubation of the cells with a non-radioactively labelled DNA precursor behave as flexible polymer chains without major constraints, and that their local conformation in the range of several microns of their contour length may be considered as random. Confocal analysis of human X chromosomes visualized in HeLa cells using FISH with a specific painting probe shows that in S-phase the chromosomes occupy distinct nuclear territories and their apparent size does not differ from that in non-S-phase cells. This observation indicates that the second level of chromosome organization also exists in S-phase chromosomes. It appears, theref ore, that the random walk/giant loop model developed earlier for G0/G1 chromosomes is also valid for S-phase chromosomes.  相似文献   
9.
Effects of tacrine (1,2,3,4-tetrahydro-9-aminoacridine) on memory deficits in rats treated with ethylcholine aziridinium ion (AF64A) were studied using active avoidance test in the two-way shuttle box. Neurotoxin AF64A injected at a dose of 6 nmol (icv, bilaterally) causes nonspecific tissue damage in hippocampal fields CA2 and CA3. Two weeks after treatment with 6 nmol, AF64A active avoidance performance of toxin-treated rats was significantly deteriorated compared to vehicle-treated animals estimated in learning test (68±3.5 and 83±3.2% of correct responses, respectively;p<0.01) and in retention test (53±5 and 76±3.6%, respectively;p<0.01). Under these conditions, chronic treatment with tacrine at a daily dose of 1 mg/kg for 12–14 d reverses the effect of AF64A on the active avoidance performance both in learning (78±3.2%) and retention (72±4%) tests. It is supposed that behavioral effects of tacrine considerably depend on a severity of neurodegeneration in the hippocampus.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号