全文获取类型
收费全文 | 1903篇 |
免费 | 108篇 |
国内免费 | 96篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 105篇 |
妇产科学 | 31篇 |
基础医学 | 190篇 |
口腔科学 | 43篇 |
临床医学 | 202篇 |
内科学 | 323篇 |
皮肤病学 | 17篇 |
神经病学 | 213篇 |
特种医学 | 221篇 |
外科学 | 195篇 |
综合类 | 59篇 |
一般理论 | 15篇 |
预防医学 | 120篇 |
眼科学 | 24篇 |
药学 | 240篇 |
中国医学 | 2篇 |
肿瘤学 | 95篇 |
出版年
2021年 | 20篇 |
2019年 | 17篇 |
2018年 | 19篇 |
2017年 | 27篇 |
2016年 | 18篇 |
2015年 | 18篇 |
2014年 | 35篇 |
2013年 | 61篇 |
2012年 | 43篇 |
2011年 | 40篇 |
2010年 | 53篇 |
2009年 | 57篇 |
2008年 | 47篇 |
2007年 | 90篇 |
2006年 | 50篇 |
2005年 | 69篇 |
2004年 | 45篇 |
2003年 | 52篇 |
2002年 | 49篇 |
2001年 | 53篇 |
2000年 | 49篇 |
1999年 | 49篇 |
1998年 | 56篇 |
1997年 | 65篇 |
1996年 | 48篇 |
1995年 | 42篇 |
1994年 | 39篇 |
1993年 | 48篇 |
1992年 | 46篇 |
1991年 | 37篇 |
1990年 | 40篇 |
1989年 | 51篇 |
1988年 | 48篇 |
1987年 | 50篇 |
1986年 | 54篇 |
1985年 | 56篇 |
1984年 | 42篇 |
1983年 | 24篇 |
1982年 | 25篇 |
1981年 | 22篇 |
1980年 | 27篇 |
1979年 | 19篇 |
1978年 | 27篇 |
1977年 | 29篇 |
1976年 | 20篇 |
1975年 | 31篇 |
1974年 | 30篇 |
1973年 | 31篇 |
1970年 | 14篇 |
1967年 | 22篇 |
排序方式: 共有2107条查询结果,搜索用时 15 毫秒
1.
2.
Orbital volume measured by a low-dose CT scanning technique. 总被引:6,自引:0,他引:6
A method for measuring orbital volume using low-dose CT with contiguous 3 mm transaxial sections is described. The accuracy of the method is 1.6%, as demonstrated by comparing CT volume measurements with those derived directly from alginate impressions and on repeat scanning the precision of the measurement was judged as 1.3%. Within the same individual, the right and left orbital volumes were observed to be within 0.6 cm3 (s.d. +/- 0.33 cm3) of each other. This study demonstrates that low-dose CT scanning is a practical method of determining orbital volume and could be used to advantage in the management of traumatic enophthalmos and blow-out fractures of the orbit. 相似文献
3.
M B Patterson J L Mack M M Neundorfer R J Martin K A Smyth P J Whitehouse 《Alzheimer disease and associated disorders》1992,6(3):145-163
Assessment of activities of daily living (ADL) in Alzheimer disease (AD) is critical in establishing the diagnosis, monitoring disease progression, evaluating the efficacy of treatment interventions, and determining the need for health and social services. The proper method to measure ADL depends on the purposes to which the scale is to be put. Existing ADL scales differ as to the type of behaviors assessed, the nature of the observations made, and the manner in which the observations are quantified. These scales were not specifically designed to evaluate changes in the nature and extent of the broad spectrum of functional difficulties seen in individuals with AD. We describe the Cleveland Scale for Activities of Daily Living (CSADL), an informant-based instrument designed to expand upon the capacity of existing physical and instrumental ADL scales by assessing both premorbid and current component acts (e.g., initiation versus implementation) of daily living functions. 相似文献
4.
Digital radiography of subtle pulmonary abnormalities: an ROC study of the effect of pixel size on observer performance 总被引:3,自引:0,他引:3
Forty conventional radiographs with examples of mild interstitial infiltrates and subtle pneumothoraces and 40 normal studies of the chest were selected and digitized, with pixel sizes of 1.0, 0.5, 0.2, and 0.1 mm. Observer performance tests were carried out using receiver operating characteristic analysis. Conventional radiographs and digitized images were compared. The results indicate that, in such cases, diagnostic accuracy increases significantly as the pixel size is reduced, at least to the 0.1-mm level. We conclude that, for digital systems using screen-film or similar image receptors, use of a pixel size substantially larger than 0.1 mm may result in some loss of diagnostic accuracy. 相似文献
5.
A combination of 65Zn-tracer determinations, oxidative analyses for glycerol, and a bioassay for uncomplexed Zn2+ have shown that: (i) zinc monoglycerolate (ZMG) dissolves in aqueous salt solutions/physiological media by dissociation into zinc ions and glycerol, but the rate and extent of ZMG dissolution depend upon pH, and/or concentration and complexing efficiency of zinc-ligands; (ii) under physiological conditions certain ligands present in skin and blood (e.g. citrate, lactate, albumin, histidine, glutathione and other thiols and, to a lesser extent, amino acids) accelerate ZMG dissolution; and (iii) there is a general correlation between the conditional stability constants (pH 7.3, 25 degrees C) of zinc-ligand complexes and the ability of given ligands to (a) solubilize ZMG in vitro and (b) mask the irritancy of Zn2+ in vivo. These observations indicate a mechanism for the transformation of ZMG applied transdermally or subcutaneously, to bioactive zinc (anti-arthritic nutritional supplement, etc.). 相似文献
6.
A useful function of any complementary medicine is to supplement some of the benefits from other treatment modalities. In rats, extracts from Indian celery seed and the NZ green-lipped mussel are powerful nutraceuticals that (i) amplify the potency of salicylates and prednisone for treating pre-established chronic inflammation (arthritis, fibrosis) and (ii) reduce the steroid's gastrotoxic and lymphopenic side effects. Such combinations might also be useful for treating inflammatory components of (a) osteoarthritis caused by microcrystalline hydroxyapatite (BCP) and (b) pseudo-gout, associated with calcium pyrophosphate crystals; that are usually refractory to monotherapy. 相似文献
7.
Cholinergic therapy in dementia 总被引:4,自引:0,他引:4
P. J. Whitehouse 《Acta neurologica Scandinavica》1993,88(S149):42-45
After reviewing the evidence for cholinergic pathology in Alzheimer's disease and related disorders, this paper reviews strategies for treating dementia using cholinomimetic drugs. Special attention is paid to cholinesterase inhibitors, particularly tacrine, the drug recently approved by the FDA. New studies suggesting that muscarinic and nicotinic cholinergic receptor active drugs may be more effective will be reviewed. Brief mention will be made of strategies to slow the progression of Alzheimer's disease. 相似文献
8.
A. Whitehouse 《Postgraduate medical journal》1997,73(855):35-38
To train junior hospital doctors more quickly and effectively as envisaged by the Calman reforms, consultants will need to develop their adult education skills. This paper describes a course set up and attended by a mixed group of Warwickshire consultants to improve their understanding of these skills. The course organisation and content is described and the ''learner-centred education'' model, educational supervision techniques, giving feedback on performance, goal setting, learning contracts and other topics covered are explained. A 12-month interval questionnaire evaluation by attendants shows that the principles taught in the course were being widely applied a year later. Thus, at a modest cost, consultants can receive a valuable basic training in adult education. 相似文献
9.
Measurement of the quadriceps femoris muscle using magnetic resonance and ultrasound imaging. 总被引:2,自引:1,他引:1 下载免费PDF全文
OBJECTIVES: To define a method for measurement of the cross sectional area and volume of the quadriceps femoris muscle using magnetic resonance imaging (MRI) in conjunction with stereology, and to compare the results of measurements obtained by the MRI method with those obtained by the conventional method of static B-mode ultrasound in order to evaluate whether MRI is a reliable alternative to ultrasound. METHODS: A preliminary MRI study was undertaken on a single female volunteer in order to optimise the scanning technique and sampling design for estimating the muscle volume using the Cavalieri method. Ten healthy volunteers participated in the method comparison study. Each volunteer underwent static B-mode ultrasonography, immediately followed by MRI. The cross sectional area of the quadriceps femoris was estimated at the junction of the proximal one third and distal two thirds of the thigh, and seven systematic sections of the thigh were obtained in order to estimate muscle volume by both modalities. RESULTS: Seven sections through the muscle are required to achieve a coefficient of error of 4-5%. There was no significant difference in the cross sectional area estimates or volume estimates when ultrasound and MRI were compared. CONCLUSION: Muscle cross sectional area and volume can be measured without bias by MRI in conjunction with stereological methods and the method is a reliable alternative to static B-mode ultrasound for this purpose. 相似文献
10.
Orbital volume measurement in the management of pure blowout fractures of the orbital floor. 总被引:8,自引:1,他引:7
D G Charteris C H Chan R W Whitehouse J L Noble 《The British journal of ophthalmology》1993,77(2):100-102
With the recent advent of accurate orbital volume assessment by computed tomography, a retrospective analysis was made of 31 patients with 'pure' blowout fracture of the orbital floor, managed either surgically or conservatively, to determine whether orbital volume measurement could provide an additional parameter of use in the management of such fractures. There was a significant difference in orbital volume discrepancy between patients managed surgically or conservatively suggesting that this investigation may be of use in decision making on surgical intervention in patients with orbital blowout fractures. 相似文献