全文获取类型
收费全文 | 1075篇 |
免费 | 61篇 |
国内免费 | 59篇 |
专业分类
儿科学 | 54篇 |
妇产科学 | 15篇 |
基础医学 | 54篇 |
口腔科学 | 14篇 |
临床医学 | 150篇 |
内科学 | 251篇 |
皮肤病学 | 18篇 |
神经病学 | 55篇 |
特种医学 | 241篇 |
外科学 | 147篇 |
综合类 | 33篇 |
预防医学 | 65篇 |
眼科学 | 13篇 |
药学 | 38篇 |
中国医学 | 2篇 |
肿瘤学 | 45篇 |
出版年
2022年 | 4篇 |
2021年 | 12篇 |
2020年 | 8篇 |
2019年 | 7篇 |
2018年 | 17篇 |
2017年 | 7篇 |
2016年 | 4篇 |
2015年 | 19篇 |
2014年 | 27篇 |
2013年 | 37篇 |
2012年 | 30篇 |
2011年 | 23篇 |
2010年 | 30篇 |
2009年 | 25篇 |
2008年 | 25篇 |
2007年 | 52篇 |
2006年 | 19篇 |
2005年 | 24篇 |
2004年 | 22篇 |
2003年 | 20篇 |
2002年 | 23篇 |
2001年 | 19篇 |
2000年 | 15篇 |
1999年 | 17篇 |
1998年 | 52篇 |
1997年 | 38篇 |
1996年 | 62篇 |
1995年 | 46篇 |
1994年 | 41篇 |
1993年 | 49篇 |
1992年 | 16篇 |
1991年 | 16篇 |
1990年 | 26篇 |
1989年 | 29篇 |
1988年 | 37篇 |
1987年 | 46篇 |
1986年 | 33篇 |
1985年 | 34篇 |
1984年 | 18篇 |
1983年 | 11篇 |
1982年 | 13篇 |
1981年 | 22篇 |
1980年 | 19篇 |
1979年 | 11篇 |
1978年 | 15篇 |
1977年 | 15篇 |
1976年 | 7篇 |
1975年 | 10篇 |
1974年 | 5篇 |
1973年 | 4篇 |
排序方式: 共有1195条查询结果,搜索用时 0 毫秒
61.
62.
PB Greer K Dahl MA Ebert M White C Wratten P Ostwald P Pichler JW Denham 《Journal of Medical Imaging and Radiation Oncology》2008,52(5):517-524
The aims of this study were to investigate whether intrafraction prostate motion can affect the accuracy of online prostate positioning using implanted fiducial markers and to determine the effect of prostate rotations on the accuracy of the software‐predicted set‐up correction shifts. Eleven patients were treated with implanted prostate fiducial markers and online set‐up corrections. Orthogonal electronic portal images were acquired to determine couch shifts before treatment. Verification images were also acquired during treatment to assess whether intrafraction motion had occurred. A limitation of the online image registration software is that it does not allow for in‐plane prostate rotations (evident on lateral portal images) when aligning marker positions. The accuracy of couch shifts was assessed by repeating the registration measurements with separate software that incorporates full in‐plane prostate rotations. Additional treatment time required for online positioning was also measured. For the patient group, the overall postalignment systematic prostate errors were less than 1.5 mm (1 standard deviation) in all directions (range 0.2–3.9 mm). The random prostate errors ranged from 0.8 to 3.3 mm (1 standard deviation). One patient exhibited intrafraction prostate motion, resulting in a postalignment prostate set‐up error of more than 10 mm for one fraction. In 14 of 35 fractions, the postalignment prostate set‐up error was greater than 5 mm in the anterior–posterior direction for this patient. Maximum prostate rotations measured from the lateral images varied from 2° to 20° for the patients. The differences between set‐up shifts determined by the online software without in‐plane rotations to align markers, and with rotations applied, was less than 1 mm (root mean square), with a maximum difference of 4.1 mm. Intrafraction prostate motion was found to reduce the effectiveness of the online set‐up for one of the patients. A larger study is required to determine the magnitude of this problem for the patient population. The inability in the current software to incorporate in‐plane prostate rotations is a limitation that should not introduce large errors, provided that the treatment isocentre is positioned near the centre of the prostate. 相似文献
63.
The authors review the function, reliability, risks, and clinical applications of skin surface blood gas monitoring that have become evident during the first decade of its clinical use. Also discussed is the problem of data expression and the recent developments in this area. 相似文献
64.
OBJECTIVE. This article evaluates Korea's national health insurance system for the elderly by simultaneously examining disease patterns, demand for care, utilization, costs of care, and facility type. METHODS. Claim records (N = 8,306,976) for 1995 to 1997 were obtained from the Youndeoung-Po district for four insurance categories. Utilization is examined using a probit model; a linear regression model is used to compare costs. FINDINGS. Insurees averaged 10.6 medical visits per year, most commonly for acute respiratory diseases. The elderly were more likely to seek care for circulatory problems, use more inpatient services, and rely on hospitals for outpatient care. Insurance costs for the elderly poor were markedly higher, and overall care for the elderly was higher per visit. DISCUSSION. By simultaneously analyzing utilization rates, disease patterns, and relative costs of care, policymakers may be able to avert a financing crisis. Stronger pricing strategies and better disease targeting would adjust utilization and increase efficiency of health expenditures. 相似文献
65.
66.
67.
JW Gregory SA Greene RT Jung CM Scrimgeour MJ Rennie 《Archives of disease in childhood》1993,68(2):205-209
Fourteen children receiving one year of recombinant human growth hormone (rhGH) treatment underwent measurement of serial changes in body composition (measured by skinfold thickness, bioelectrical impedance, and H2(18)O dilution), resting energy expenditure (REE, estimated by ventilated hood indirect calorimetry), and total free living daily energy expenditure (TEE, measured by the doubly labelled water technique). Mean height velocity increased from 4.9 to 8.6 cm/year after six months of treatment. Fat free mass (FFM) increased more during the first six weeks (24.4 g/day) than from six to 26 weeks of treatment (6.8 g/day); fat mass decreased by 7.2 g/day and 1.1 g/day respectively. The six week increase in REE (kJ/day) was maintained after six months of treatment, though expressed per kilogram FFM (kJ/kgFFM/day), returned to pretreatment values by three months. Height velocity increases at six months correlated with six week changes in fat mass measured by skinfold thickness and REE, though use of this relationship to predict growth response in individuals is limited by the wide 95% prediction intervals. No significant changes in growth, body composition, or energy expenditure were observed between six and 12 months of treatment, in either patients who had initially responded well to treatment or those who were poor initial responders to treatment and who had their dose of rhGH doubled after six months. 相似文献
68.
69.
Age-related postural deficits elicit compensatory mechanisms such as ankle dorsiflexion in the elderly. To gain further insight into this problem, the ability to match an ankle angle during quiet stance was studied in 12 elderly and 12 young subjects. Following an initial single limb angular perturbation presented in the ±4° range, a subject had to return a tilt platform to level, as determined by the nonperturbed limb. Elderly subjects exhibited significant positive (0.9°) over-shoot of the level position, in contrast to young subjects who matched ankle angle with a mean error of −0.1°. The elderly group also exhibited an increase in positioning error for angular displacements in the range between −1 and +1°. The results document age-related postural changes in ankle positioning which might affect postural stability in older adults. 相似文献
70.
Multiple myeloma: evaluation by CT 总被引:3,自引:0,他引:3
Although patients who have multiple myeloma usually have straightforward clinical symptoms and corroborative radiographs, in some instances, these patients will present atypically, with symptoms suggesting active disease but radiographs that are normal or nonspecific. We reviewed the records of 32 patients who had documented multiple myeloma and had undergone CT examinations, assessing the value of those examinations. Although CT is not indicated in all patients who have multiple myeloma, it is especially useful in patients who have bone pain and normal or nonspecific radiographs. CT provided confirmatory information in all cases in which lesions were seen on radiographs. CT also frequently demonstrated a greater extent of disease than could be appreciated on the radiographs. 相似文献