全文获取类型
收费全文 | 12480篇 |
免费 | 1241篇 |
国内免费 | 302篇 |
专业分类
耳鼻咽喉 | 145篇 |
儿科学 | 163篇 |
妇产科学 | 114篇 |
基础医学 | 1072篇 |
口腔科学 | 248篇 |
临床医学 | 1553篇 |
内科学 | 1736篇 |
皮肤病学 | 84篇 |
神经病学 | 979篇 |
特种医学 | 1632篇 |
外国民族医学 | 4篇 |
外科学 | 1424篇 |
综合类 | 1742篇 |
现状与发展 | 2篇 |
预防医学 | 509篇 |
眼科学 | 125篇 |
药学 | 707篇 |
3篇 | |
中国医学 | 134篇 |
肿瘤学 | 1647篇 |
出版年
2024年 | 45篇 |
2023年 | 348篇 |
2022年 | 789篇 |
2021年 | 1019篇 |
2020年 | 828篇 |
2019年 | 734篇 |
2018年 | 751篇 |
2017年 | 738篇 |
2016年 | 798篇 |
2015年 | 796篇 |
2014年 | 982篇 |
2013年 | 931篇 |
2012年 | 700篇 |
2011年 | 664篇 |
2010年 | 520篇 |
2009年 | 508篇 |
2008年 | 472篇 |
2007年 | 378篇 |
2006年 | 346篇 |
2005年 | 287篇 |
2004年 | 258篇 |
2003年 | 188篇 |
2002年 | 141篇 |
2001年 | 163篇 |
2000年 | 109篇 |
1999年 | 71篇 |
1998年 | 62篇 |
1997年 | 60篇 |
1996年 | 62篇 |
1995年 | 77篇 |
1994年 | 39篇 |
1993年 | 32篇 |
1992年 | 30篇 |
1991年 | 23篇 |
1990年 | 14篇 |
1989年 | 10篇 |
1988年 | 8篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1984年 | 2篇 |
1983年 | 6篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
William R. Reinus M.D. Franz J. Wippold II M.D. Kavita K. Erickson M.D. 《Emergency radiology》1994,1(2):81-84
We studied clinical predictors of cranial computed tomography (CT) abnormalities in patients with acute or acutely worsened
headache. Data were collected from chart review of 333 consecutive patients presenting to an emergency department and who
were clinically selected for cranial CT. Patients with a positive neurologic examination were at 10.7 times greater risk for
a positive CT than the rest of the sample (p<1.5 – 10−10). Using only neurologic examination to select patients for CT would have missed 30.3% of the positive scans. The amnesia,
depressed sensorium, and hypertension variables had CT yields approximating 10% or greater even in the presence of a negative
neurologic examination. Together with a positive neurologic examination, these variables detected 87.9% of the patients in
this sample with positive scans; their absence had a negative predictive value of 98.0%. Of the four patients with positive
scans who would have been missed using this strategy, one was discharged directly from the emergency department anyway and
the other three developed positive neurologic examinations within 24 hours. One died of causes unrelated to the intracranial
pathology. Positive neurologic examination, hypertension, history of amnesia, or a depressed sensorium provide reasonable
initial guidelines to select for CT patients with an acute headache. 相似文献
52.
53.
372���Ǽ��Լ�״��������������� 总被引:14,自引:0,他引:14
目的 探讨辅助检查在诊断亚急性甲状腺炎中的作用。方法 回顾分析372例亚急性甲状腺炎病人所做的各项辅助检查结果。结果 血沉,B超,彩色多普勒,甲状腺核素扫描,甲状腺吸^131I率测定,细针穿刺细胞学,TMA,TGA等项检查诊断本病的阳性率分别为93.75%,81.63%,95.62%,89.66%,69.70%,89.41%,13.46%和9.62%。T3,T4,TSH检查结果随着病程的进展变化较大。结论 血沉检查对诊断本病缺乏特异性;彩色多普勒,细针穿刺细胞学检查诊断率高,特异性强,是首选的检查手段;甲状腺核素扫描可以准确地反映甲状腺功能状态;检测血清中T3,T4,TSH水平可以协助诊断本病,判断疾病所处时期。 相似文献
54.
Rita Noumeir 《Journal of digital imaging》2006,19(4):295-306
Recently, the digital imaging and communications in medicine (DICOM) standard introduced rules for the encoding, transmission,
and storage of the imaging diagnostic report. This medical document can be stored and communicated with the images in picture
archiving and communication system (PACS). It is a structured document that contains text with links to other data such as
images, waveforms, and spatial or temporal coordinates. Its structure, along with its wide use of coded information, enables
the semantic understanding of the data that is essential for the Electronic Healthcare Record deployment. In this article,
we present DICOM Structured Report (SR) and discuss its benefits. We show how SR enables efficient radiology workflow, improves
patient care, optimizes reimbursement, and enhances the radiology ergonomic working conditions. As structured input significantly
alters the interpretation process, understanding all its benefits is necessary to support the change.
Biography Rita Noumeir is a professor at the Department of Electrical Engineering of the University of Quebec, école de Technologie Superieure in
Montreal. A founding member of the Imaging, Vision, and Artificial Intelligence Laboratory (LIVIA), her main research interest
is the Healthcare Information Technology, specifically, Interoperability, Electronic Patient Record, Security, Information
Confidentiality, and Image Processing.
As a member of both Technical and Planning International IHE Radiology Committees, Dr. Noumeir took part over the last 5 years
in developing many Integrating the Healthcare Enterprise (IHE) Integration Profiles in Radiology and in organizing several
Integration Demonstrations. She is a cofounder of IHE Canada.
Dr. Noumeir contributed to many research and development projects in collaboration with several Canadian and international
companies in medical imaging and healthcare information. Currently, she collaborates with the Diagnostic Imaging Team of Canada
Health Infoway to define the principles and architecture for sharing imaging information between multiple healthcare institutions.
She plays a leading role in the development of this solution that is published as an IHE Integration Profile for which she
is the editor.
Rita Noumeir holds a Ph.D. and a Masters degree in Biomedical Engineering from école Polytechnique of Montreal specializing
in Medical Imaging. She is a professional engineer, and a member of the Ordre des ingénieurs du Québec. 相似文献
55.
H. J. C. M. Sterenborg M. Motamedi R. F. Wagner Jr M. Duvic S. Thomsen S. L. Jacques 《Lasers in medical science》1994,9(3):191-201
The feasibility of using in vivo autofluorescence for the diagnosis of skin cancer was evaluated. In vivo fluorescence measurements
were performed on healthy human volunteers, and patients with different types of benign and malignant skin tumours. Fluorescence
spectra as well as fluorescence images were acquired. The excitation-emission matrix of normal skin (n=3) showed a broad peak at the shortest excitation wavelength (365 nm) and at 440 nm fluorescence wavelength, smoothly decreasing
towards longer excitation and fluorescence wavelengths. Non-melanoma skin tumours (n=31) and control skin excited with 375 nm showed a broad fluorescence band from 400 to 700 nm, peaking around 436 nm. No significant
differences in measurements between tumours and the corresponding control sites were found. A large spatial variation in the
fluorescence intensity was observed both in the tumours and in the control sites. Standard deviations found ranged from 0.15
to 1.5 times the mean fluorescence. Fluorescence images, excited with 375 nm and taken with an image intensified CCD camera,
on eight malignant melanomas and eight benign pigmented lesions did not indicate any fluorescence intensity distribution specific
to the malignancy of the lesion. Neither the shape of the fluorescence spectra, nor the spatial distribution of the fluorescence
intensity showed any signature specific to the histopathological nature of the lesions investigated. Optical diagnostics of
skin tumours using the autofluorescence does not seem to be feasible at the present time. 相似文献
56.
目的提高对颈静脉球瘤的影像学认识和诊断。方法对8例经病理明确诊断的颈静脉球瘤的影像学资料进行回顾性分析。结果6例巨大型颈静脉球瘤MRI出现特异型表现,即典型的“盐和胡椒”征;DSA检查不仅能够术前明确肿瘤供血血管,而且同时进行栓塞治疗可减少随后术中出血。结论MRI DSA是巨大型颈静脉球瘤术前最有价值的影像学检查工具。 相似文献
57.
弥散张量磁共振成像方法概述 总被引:1,自引:0,他引:1
弥散张量成像(diffusion tensor imaging,DTI)是一种根据组织内水分子的弥散特性来探测有机体的微观结构和病理改变的核磁共振成像方法,目前已经成为临床评估和生命科学研究重要的工具。本文结合近年来的文献综述了弥散张量成像的基本原理,列举了目前常用的成像方法,分析了它们的优缺点以及用途,并对弥散张量成像的发展方向作了一些展望。 相似文献
58.
女性控尿解剖学机制的MRI研究 总被引:1,自引:1,他引:0
目的探讨女性控尿的解剖学机制在MRI(磁共振成像)的表现和观察方法。方法对20例正常控尿的成年女性进行MRI扫描,采用八通道体部线圈、快束自旋回波(FSE)扫描序列进行扫描,采集静息时盆腔横断面、矢状面和冠状面影像。结果MRI显示,女性的尿道分三层结构,与病理学对照,由内向外依次为黏膜及黏膜下组织、肌肉、外膜组织,但无法区分平滑肌与括约肌;与控尿有关的盆底肌肉也能够清楚显示。结论MRI能够清楚观察到女性控尿的有关解剖结构,是观察女性控尿解剖结构的较理想影像方法。 相似文献
59.
Granulysin: A Novel Host Defense Molecule 总被引:5,自引:0,他引:5
Granulysin is a novel cationic molecule present in the granules of cytotoxic T lymphocytes and natural killer cells. Cytotoxic T lymphocytes have long been associated with graft destruction in transplant rejection. Recent studies implicate granulysin in cell-mediated cytotoxicity, chemoattraction, immune activation and as a potential diagnostic biomarker for transplant rejection. 相似文献
60.
腮腺间隙良性肿瘤的MRI诊断 总被引:1,自引:0,他引:1
目的探讨腮腺间隙常见良性肿瘤的影像特征及其诊断与鉴别诊断。方法良性肿瘤20例,包括多形性腺瘤13例、乳头状淋巴囊腺瘤3例、淋巴管瘤2例、血管瘤1例、脂肪瘤1例。经手术病理证实15例,穿刺活检证实4例,典型MR特征结合病史确诊1例。结果13例多形性腺瘤中有11例位于腮腺浅叶,2例位于深叶;9例表现为均匀等T1长T2信号.4例在T2WI上信号明显不均匀;静脉注射Gd—UIPA后3例瘤实质均匀强化,4例增强后明显不均匀强化。3例Warthin瘤中2例发生于一侧,1例累及双侧腮腺,在T1WI上呈低信号,T2WI上信号等于或低于正常腺实质,增强后无明显强化。2例淋巴管瘤呈明显长T1长T2信号,并有多房现象。1例血管瘤信号不均质,呈明显长T1长T2信号,静1脉注射Gd—DTPA后病变往往显著异常强化。1例脂肪瘤在T1WI及T2WI上均表现为明显高信号强度。结论运用MR成像研究腮腺间隙的良性肿瘤,有利于疾病的定位,有助于病变的诊断与鉴别诊断。 相似文献