全文获取类型
收费全文 | 11429篇 |
免费 | 839篇 |
国内免费 | 99篇 |
专业分类
耳鼻咽喉 | 89篇 |
儿科学 | 341篇 |
妇产科学 | 269篇 |
基础医学 | 1278篇 |
口腔科学 | 173篇 |
临床医学 | 1062篇 |
内科学 | 2421篇 |
皮肤病学 | 155篇 |
神经病学 | 823篇 |
特种医学 | 411篇 |
外科学 | 1782篇 |
综合类 | 257篇 |
一般理论 | 7篇 |
预防医学 | 688篇 |
眼科学 | 977篇 |
药学 | 744篇 |
中国医学 | 70篇 |
肿瘤学 | 820篇 |
出版年
2023年 | 104篇 |
2022年 | 140篇 |
2021年 | 295篇 |
2020年 | 184篇 |
2019年 | 268篇 |
2018年 | 308篇 |
2017年 | 208篇 |
2016年 | 204篇 |
2015年 | 254篇 |
2014年 | 321篇 |
2013年 | 403篇 |
2012年 | 620篇 |
2011年 | 686篇 |
2010年 | 402篇 |
2009年 | 367篇 |
2008年 | 611篇 |
2007年 | 705篇 |
2006年 | 669篇 |
2005年 | 649篇 |
2004年 | 587篇 |
2003年 | 541篇 |
2002年 | 498篇 |
2001年 | 444篇 |
2000年 | 397篇 |
1999年 | 323篇 |
1998年 | 120篇 |
1997年 | 97篇 |
1996年 | 89篇 |
1995年 | 68篇 |
1994年 | 67篇 |
1993年 | 69篇 |
1992年 | 180篇 |
1991年 | 173篇 |
1990年 | 153篇 |
1989年 | 119篇 |
1988年 | 132篇 |
1987年 | 146篇 |
1986年 | 101篇 |
1985年 | 98篇 |
1984年 | 61篇 |
1983年 | 73篇 |
1982年 | 47篇 |
1981年 | 42篇 |
1980年 | 42篇 |
1979年 | 67篇 |
1978年 | 49篇 |
1977年 | 21篇 |
1975年 | 15篇 |
1973年 | 17篇 |
1972年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Efficacy of radical neck dissection for the control of cervical metastasis after radiotherapy for nasopharyngeal carcinoma 总被引:5,自引:0,他引:5
Fifty-one patients who had persistent or recurrent neck disease from nasopharyngeal carcinoma after radiotherapy underwent radical neck dissection. The follow-up period ranged from 0.5 to 9 years (median: 2 years). Multiple cervical lymph node involvement was present in 51% of the patients (26 of 51). Malignant cells were detected in 88% of the resected specimens (45 of 51). The clinical sign of fixation of lymph node is the only factor that affects the successful control of neck disease (p = 0.04). Extracapsular extension of the nodal disease was present, and 35% of the lymph nodes were adherent to surrounding structures at operation (18 of 51). There was one hospital mortality and the overall morbidity was minimal. The actuarial survival at 5 years was 38%, and the probability of control of neck disease was 66%. Radical neck dissection is effective in controlling post-irradiation cervical metastasis from nasopharyngeal carcinoma. 相似文献
22.
Elevation of prostaglandins and protein in the aqueous humor is an immediate response to Yag-laser anterior capsulotomy. There was a significant correlation between prostaglandins and thromboxane to the elevation of intraocular pressure. The elevation of protein concentration was proportional to the elevation of prostaglandin F1, but not to thromboxane. The biochemical changes in the aqueous humor were more severe as laser power was increased above 3 mj. While the role of prostaglandins in the elevation of intraocular pressure is uncertain, the present data recommend the selection of laser power below 3 mj to avoid pressure rise instead of inhibition of all prostaglandin synthesis by medication. 相似文献
23.
24.
Andrew K. C. Lam Abby Lam Jessie Charm Kwai-mui Wong 《Ophthalmic & physiological optics》2005,25(2):162-167
PURPOSE: This study compared the near phoria measurement using the Bernell muscle balance card with and without prism neutralization, using both trial frame and phoropter correction, and compared with the conventional Maddox rod method. METHODS: Forty young normal Chinese adults had their near phoria measured with trial frame correction using the conventional muscle balance card method (method 1). Any deviation was compensated with a prism bar as an alternative approach (method 2). The conventional Maddox rod method (method 3) was also carried out for comparison. These three methods were repeated with phoropter correction and considered as methods 4, 5 and 6. RESULTS: The phorias obtained from these six methods were not significantly different from each other (repeated measures anova, p > 0.05). More than half of the subjects were exophoric. Although the difference in phoria was not significant, phoria measurement using phoropter correction yielded a greater coefficient of variation. CONCLUSIONS: Near phoria measurement using the muscle balance card conducted with trial frame correction was less variable, and was also more natural and similar to a real reading situation. The use of prism for compensation did not affect the phoria results. Exophoria seems to be more common than esophoria in young Chinese adults. 相似文献
25.
26.
27.
Hernando Olivar John S. Bramhall Irene Rozet Monica S. Vavilala Michael J. Souter Lorri A. Lee Arthur M. Lam 《Journal canadien d'anesthésie》2007,54(10):829-834
PURPOSE: Lumbar subarachnoid catheters for cerebrospinal fluid (CSF) drainage (lumbar drains) are indicated for several medical and surgical conditions. A number of complications can occur from the placement of this type of catheter, including catheter breakage from excessive traction or shearing over the Tuohy needle. CLINICAL FEATURES: Five cases of lumbar subarachnoid catheter breakage/shearing and catheter fragment retention, as well as one near miss, were identified over a one-year period at a single institution. All (n = 6) patients were undergoing neurosurgical procedures. Four patients required surgical retrieval of the catheter fragments. No patient experienced log-term neurological sequelae. DISCUSSION: From these experiences, the following risks factors for catheter rupture are identified: 1) intentional or accidental retraction of the catheter through the needle during placement; 2) faulty use of the guidewire; or 3) use of excessive force during removal of the catheter. Methods to prevent such complications are suggested, including minimal use, or complete avoidance of a guidewire. 相似文献
28.
29.
We have investigated contamination of extradural catheters during normal
handling with starch powdered gloves. In the laboratory, extradural
catheters were handled in sterile fields with both powdered and
non-powdered gloves, simulating preparation for patient insertion. The
catheters together with glove samples were then examined using a Zeiss 940
scanning electron microscope. Microscopy of samples revealed starch
contamination of the catheters handled with powdered gloves, especially in
the side hole areas. We conclude that extradural catheters may be
contaminated easily by starch powder from surgical gloves. This powder may
then be deposited into the extradural space. The effect of starch in the
extradural space is not known but starch is known to cause inflammatory and
granulomatous reactions in other parts of the body as well as being
directly allergenic. Powder contamination of catheters may be avoided
easily by the use of powder-free gloves and we feel that these should be
used whenever possible.
相似文献
30.
A comprehensive study of smoking in primary school children in Hong Kong: implications for prevention.
下载免费PDF全文
![点击此处可从《Journal of epidemiology and community health》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J Peters A J Hedley T H Lam C L Betson C M Wong 《Journal of epidemiology and community health》1997,51(3):239-245
STUDY OBJECTIVE: To identify factors associated with smoking behaviour in primary school children in Hong Kong. DESIGN: A cross sectional survey in which both children and parents completed questionnaires. The main outcome measure was the smoking status of the children; and risk factors (knowledge of and attitude to smoking and demographic and socioeconomic background) were identified as predictors of ever/never smoking. SETTING AND SUBJECTS: Altogether 9598 primary school children, aged 8-13 years, and attending 27 schools from two districts in Hong Kong participated. MAIN RESULTS: The prevalence of ever-smoking was 12% (1119)-15% (760) in boys and 7% (359) in girls. It ranged from 3% in 8 year old girls to 52% in 13 year old boys. The factors associated with ever-smoking included the following: being a boy (adjusted odds ratio 2.21; 95% confidence interval 1.89, 2.59), increasing age per year (1.48; 1.40, 1.57), living in Kwai Tsing district (1.29; 1.10, 1.50), having one or more smokers at home (2.07; 1.78, 2.39), and having a father who was not working (1.41; 1.19, 1.67). Children who were ever-smokers had both seen and approved of their friends' smoking (8.79; 5.33, 14.50), had a more positive attitude towards smoking (3.35; 2.21, 5.09), and were more successful in recognising cigarette brand names and logos (1.67; 1.42, 1.96), but they lacked confidence (1.78; 1.32, 2.39). CONCLUSIONS: The influences on child smoking are multifactorial and programmes in Hong Kong are falling to curb them. The control of these risk factors must be incorporated in the smoking prevention policy of Hong Kong and supported by future enforced legislation. 相似文献