全文获取类型
收费全文 | 7342篇 |
免费 | 661篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 272篇 |
妇产科学 | 180篇 |
基础医学 | 1112篇 |
口腔科学 | 129篇 |
临床医学 | 857篇 |
内科学 | 1557篇 |
皮肤病学 | 68篇 |
神经病学 | 675篇 |
特种医学 | 302篇 |
外科学 | 882篇 |
综合类 | 112篇 |
现状与发展 | 1篇 |
一般理论 | 5篇 |
预防医学 | 718篇 |
眼科学 | 158篇 |
药学 | 502篇 |
中国医学 | 2篇 |
肿瘤学 | 444篇 |
出版年
2021年 | 106篇 |
2020年 | 56篇 |
2019年 | 88篇 |
2018年 | 142篇 |
2017年 | 84篇 |
2016年 | 78篇 |
2015年 | 120篇 |
2014年 | 158篇 |
2013年 | 247篇 |
2012年 | 385篇 |
2011年 | 436篇 |
2010年 | 272篇 |
2009年 | 246篇 |
2008年 | 409篇 |
2007年 | 467篇 |
2006年 | 410篇 |
2005年 | 386篇 |
2004年 | 355篇 |
2003年 | 420篇 |
2002年 | 331篇 |
2001年 | 127篇 |
2000年 | 152篇 |
1999年 | 162篇 |
1998年 | 113篇 |
1997年 | 93篇 |
1996年 | 73篇 |
1995年 | 67篇 |
1994年 | 81篇 |
1993年 | 75篇 |
1992年 | 122篇 |
1991年 | 123篇 |
1990年 | 118篇 |
1989年 | 119篇 |
1988年 | 104篇 |
1987年 | 106篇 |
1986年 | 89篇 |
1985年 | 93篇 |
1984年 | 64篇 |
1983年 | 57篇 |
1982年 | 48篇 |
1981年 | 43篇 |
1979年 | 84篇 |
1978年 | 56篇 |
1976年 | 43篇 |
1975年 | 39篇 |
1974年 | 55篇 |
1973年 | 39篇 |
1972年 | 42篇 |
1971年 | 46篇 |
1970年 | 44篇 |
排序方式: 共有8018条查询结果,搜索用时 709 毫秒
91.
Saravelos Harry G.; Li Tin-Chiu; Cooke Ian D. 《Human reproduction (Oxford, England)》1995,10(11):2887-2894
We evaluated 81 women with adnexal adhesions and no male factorwho underwent microsurgical (n = 59) and laparoscopic (n = 22)adhesiolysis for infertility. The cumulative conception ratesfor all 81 patients at 12 and 24 months were 41 and 44% respectively.The impact of the following variables on cumulative conceptionrates for all patients was examined: age, duration of infertility,type of infertility, ovulatory status, presence and stage ofendometriosis, adhesion grade, adnexal status (bilateral orunilateral disease, unilateral tubal absence), history of previoussurgery, history of pelvic inflammatory disease and treatmentmodality (microsurgical versus laparoscopic). The results ofindependent comparisons of subgroups within each of these variablesmay be biased because of the interrelationships between thevariables. To overcome this problem, a stepwise Cox's proportionalhazards regression analysis was employed. Our analysis showedthat the single most significant variable influencing the cumulativeconception rates was the duration of infertility (P < 0.005).For every additional year of infertility, the probability ofpregnancy after adhesiolysis (microsurgical or laparoscopic)was reduced by 20%. Cumulative conception rates at 12 and 24months after microsurgical adhesiolysis were 36 and 40% respectively,while after laparoscopic adhesiolysis they were 57% at 12 and24 months. When imbalances were adjusted between the two treatmentgroups, there was no statistically significant difference betweenthe cumulative conception rates for microsurgical and laparoscopicadhesiolysis. 相似文献
92.
93.
Changes in mean trabecular orientation in the medial condyle of the proximal tibia in osteoarthritis 总被引:1,自引:0,他引:1
In osteoarthritis of the knee, degenerative changes occur in the articular cartilage and underlying subchondral bone, particularly of the medial tibial condyle. Cancellous bone sclerosis that accompanies osteoarthritis is not only the result of an increase in bone volume fraction but also a change in trabecular structure. In a comparison with agematched controls (n=4), osteoarthritis (n=11) demonstrated a significant (P0.05) increase in bone volume fraction and trabecular thickness. Overal trabecular orientation in the osteoarthritic group was more vertical or perpendicular to the articular surface than the control group (P0.05) especially in the trabeculae of the cancellous bone layer closest to the articular surface. These alterations in trabecular bone structure could have significant consequences for the mechanical properties of osteoarthritic bone. 相似文献
94.
Screening methods for thyroid hormone disruptors 总被引:15,自引:0,他引:15
DeVito M Biegel L Brouwer A Brown S Brucker-Davis F Cheek AO Christensen R Colborn T Cooke P Crissman J Crofton K Doerge D Gray E Hauser P Hurley P Kohn M Lazar J McMaster S McClain M McConnell E Meier C Miller R Tietge J Tyl R 《Environmental health perspectives》1999,107(5):407-415
The U.S. Congress has passed legislation requiring the EPA to implement screening tests for identifying endocrine-disrupting chemicals. A series of workshops was sponsored by the EPA, the Chemical Manufacturers Association, and the World Wildlife Fund; one workshop focused on screens for chemicals that alter thyroid hormone function and homeostasis. Participants at this meeting identified and examined methods to detect alterations in thyroid hormone synthesis, transport, and catabolism. In addition, some methods to detect chemicals that bind to the thyroid hormone receptors acting as either agonists or antagonists were also identified. Screening methods used in mammals as well as other vertebrate classes were examined. There was a general consensus that all known chemicals which interfere with thyroid hormone function and homeostasis act by either inhibiting synthesis, altering serum transport proteins, or by increasing catabolism of thyroid hormones. There are no direct data to support the assertion that certain environmental chemicals bind and activate the thyroid hormone receptors; further research is indicated. In light of this, screening methods should reflect known mechanisms of action. Most methods examined, albeit useful for mechanistic studies, were thought to be too specific and therefore would not be applicable for broad-based screening. Determination of serum thyroid hormone concentrations following chemical exposure in rodents was thought to be a reasonable initial screen. Concurrent histologic evaluation of the thyroid would strengthen this screen. Similar methods in teleosts may be useful as screens, but would require indicators of tissue production of thyroid hormones. The use of tadpole metamorphosis as a screen may also be useful; however, this method requires validation and standardization prior to use as a broad-based screen. 相似文献
95.
The dissemination of a smoking cessation program to 23 antenatal clinics: the predictors of initial program adoption by managers 总被引:2,自引:0,他引:2
Cooke M Mattick RP Campbell E 《Australian and New Zealand journal of public health》1999,23(1):99-103
Objective: To investigate whether the method of dissemination, antenatal clinic practice norms for smoking intervention and subjective evaluation of the attributes of a new smoking cessation program are associated with a nurse unit manager's initial decision to adopt the new program.
Method: Twenty-three hospital clinics were randomly allocated to two groups which received the program either by simple or intensive dissemination methods. Simple dissemination involved a mailout of the 'Fresh Start' program and intensive dissemination involved a mailout which was enhanced by personal contact with midwifery facilitators who provided support and training for the program. It was hypothesised that intensive dissemination would improve program adoption compared to simple dissemination. It was also hypothesised that managers' perceptions of the program and clinic smoking intervention practice norms would predict program adoption. A hierarchical regression analysis was used to examine the association between these variables and the adoption of program components.
Results: The results indicated that the method of dissemination and the managers' perceptions of the program are significant predictors of program adoption.
Conclusions: Although clinic practice norm for smoking cessation education is not a significant predictor of program adoption, it appears to mediate managers' perceptions of the program. 相似文献
Method: Twenty-three hospital clinics were randomly allocated to two groups which received the program either by simple or intensive dissemination methods. Simple dissemination involved a mailout of the 'Fresh Start' program and intensive dissemination involved a mailout which was enhanced by personal contact with midwifery facilitators who provided support and training for the program. It was hypothesised that intensive dissemination would improve program adoption compared to simple dissemination. It was also hypothesised that managers' perceptions of the program and clinic smoking intervention practice norms would predict program adoption. A hierarchical regression analysis was used to examine the association between these variables and the adoption of program components.
Results: The results indicated that the method of dissemination and the managers' perceptions of the program are significant predictors of program adoption.
Conclusions: Although clinic practice norm for smoking cessation education is not a significant predictor of program adoption, it appears to mediate managers' perceptions of the program. 相似文献
96.
Medical rapid prototyping and 3D CT in the manufacture of custom made cranial titanium plates 总被引:10,自引:0,他引:10
Winder J Cooke RS Gray J Fannin T Fegan T 《Journal of medical engineering & technology》1999,23(1):26-28
This report describes a new method of custom making cranial titanium plates for the repair of skull defects. We have combined 3D CT imaging and surface modelling with rapid prototyping (RP) technology to produce physical models of our patients' skulls from which custom titanium plates were made. We have expanded the use of image processing tools applied to the CT image data to fabricate a representation of the skull defect. Medical RP models are relatively expensive and particular attention has been paid to developing image processing methods to reduce costs. Our technique used the patient as their own model and generated data from the contralateral side of the head where appropriate. We present the results of 10 patients who have had a custom made cranial titanium plate fitted and discuss the models for these cases. The benefits of our custom made titanium plates are reduced patient attendances to hospital and a more accurate titanium plate which has improved fitting and cosmesis. 相似文献
97.
98.
99.
Compliance with oral corticosteroids during steroid trials in chronic airways obstruction. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Thorax》网站下载免费的PDF全文](/ch/ext_images/free.gif)
BACKGROUND: Corticosteroid trials are an important part of the assessment of patients with chronic airways obstruction, but false negative results will occur if the treatment is not taken. To determine compliance low dose phenobarbitone has been used as a marker. METHODS: Thirty six patients referred to a chest clinic for assessment of their airways obstruction were studied. They were instructed to take eight capsules (each containing 5 mg prednisolone and 0.5 mg phenobarbitone) per day for two weeks. The response was assessed by home peak flow monitoring and clinic spirometric tests. Plasma phenobarbitone levels were measured after the trial to enable calculation of the dose to plasma concentration ratio (level to dose ratio, LDR) and the result was compared with the reference range for fully compliant individuals. RESULTS: Five patients defaulted from follow up, 23 had LDR values within the expected range, and eight had low LDR values consistent with poor compliance. The nine patients with steroid responsive disease (> 20% improvement in peak flow or spirometric parameters) all had LDR values in the expected range. CONCLUSION: Excluding those who defaulted whose compliance must be questionable, eight (26%) patients did not fully comply with the steroid trial. Not all patients who fail to respond to a two week home steroid trial have a steroid "unresponsive" disease. 相似文献
100.