全文获取类型
收费全文 | 2236篇 |
免费 | 160篇 |
国内免费 | 12篇 |
学科分类
医药卫生 | 2408篇 |
出版年
2023年 | 15篇 |
2022年 | 13篇 |
2021年 | 95篇 |
2020年 | 55篇 |
2019年 | 55篇 |
2018年 | 72篇 |
2017年 | 59篇 |
2016年 | 68篇 |
2015年 | 80篇 |
2014年 | 106篇 |
2013年 | 126篇 |
2012年 | 180篇 |
2011年 | 185篇 |
2010年 | 80篇 |
2009年 | 107篇 |
2008年 | 146篇 |
2007年 | 122篇 |
2006年 | 101篇 |
2005年 | 132篇 |
2004年 | 120篇 |
2003年 | 97篇 |
2002年 | 100篇 |
2001年 | 14篇 |
2000年 | 7篇 |
1999年 | 16篇 |
1998年 | 26篇 |
1997年 | 13篇 |
1996年 | 12篇 |
1995年 | 13篇 |
1994年 | 10篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1987年 | 7篇 |
1985年 | 4篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1978年 | 8篇 |
1977年 | 5篇 |
1975年 | 4篇 |
1970年 | 4篇 |
1969年 | 5篇 |
1963年 | 5篇 |
1962年 | 5篇 |
1961年 | 4篇 |
1942年 | 4篇 |
1933年 | 5篇 |
1929年 | 5篇 |
排序方式: 共有2408条查询结果,搜索用时 15 毫秒
21.
Edward Chow Lori Holden Joel Rubenstein Monique Christakis Katharina Sixel Marjan Vidmar Joel Finkelstein Charles Hayter Andrew Loblaw Rebecca Wong Ewa Szumacher Cyril Danjoux 《Radiotherapy and oncology》2004,70(3):291-294
Twenty-five patients with osteolytic metastases had computed tomography (CT) scans before and 3 months after palliative radiotherapy. The median % density change following single 8 Gy, 20 Gy/5#, 30 Gy/10# were: 128 (range 98–255), 141 (79–342), and 145 (65–235), respectively. It is feasible to evaluate remineralization of osteolytic lesions with palliative radiotherapy. 相似文献
22.
Preventing Rhesus D haemolytic disease of the newborn by giving anti-D immunoglobulin: are the guidelines being adequately followed? 总被引:1,自引:0,他引:1
23.
Edward Chow Alison Ling Lori Davis Tony Panzarella Cyril Danjoux 《Radiotherapy and oncology》2005,75(1):64-69
BACKGROUND AND PURPOSE: To examine the incidence of pain flare following external beam radiotherapy and to determine what constitutes a meaningful change in pain scores in the treatment of bone metastases. PATIENTS AND METHODS: Patients with bone metastases treated with external beam radiotherapy were asked to score their pain on a scale of 0-10 before the treatment (baseline), daily during the treatment and for 10 days after completion of external beam radiation. Pain flare was defined as a two-point increase from baseline pain in the pain scale of 0-10 with no decrease in analgesic intake or a 25% increase in analgesic intake employing daily oral morphine equivalent with no decrease in pain score. To distinguish pain flare from progression of pain, we required the pain score and analgesic intake to return back to baseline levels after the increase/flare. They were also asked to indicate if their pain changed during that time compared to pre-treatment level. The change in pain score was compared with patient perception. RESULTS: Eighty-eight patients were evaluated in this study. There were 49 male and 39 female patients with the median age of 70 years. Twelve of 88 patients (14%) had pain flare on day 1. The overall incidence of pain flare during the study period ranged from 2 to 16%. A total of 797 pain scorings were obtained. Patients perceived an improvement in pain when their self-reported pain score decreased by at least two points. CONCLUSIONS: Our study confirms the occurrence of pain flare following the external beam radiotherapy in the treatment of bone metastases. Further studies are required to predict who are at risk for flare. Appropriate measures can be taken to alleviate the pain flare. The finding in the meaningful change in pain scores supports the investigator-defined partial response used in some clinical trials. 相似文献
24.
Shiloah Elizabeth Darmanayagam Khanna Nehemiah Harichandran Sunil Retmin Raj Cyril Kannan Arputharaj 《Journal of digital imaging》2013,26(3):496-509
Segmentation of lung parenchyma from the chest computed tomography is an important task in analysis of chest computed tomography for diagnosis of lung disorders. It is a challenging task especially in the presence of peripherally placed pathology bearing regions. In this work, we propose a segmentation approach to segment lung parenchyma from chest. The first step is to segment the lungs using iterative thresholding followed by morphological operations. If the two lungs are not separated, the lung junction and its neighborhood are identified and local thresholding is applied. The second step is to extract shape features of the two lungs. The third step is to use a multilayer feed forward neural network to determine if the segmented lung parenchyma is complete, based on the extracted features. The final step is to reconstruct the two lungs in case of incomplete segmentation, by exploiting the fact that in majority of the cases, at least one of the two lungs would have been segmented correctly by the first step. Hence, the complete lung is determined based on the shape and region properties and the incomplete lung is reconstructed by applying graphical methods, namely, reflection and translation. The proposed approach has been tested in a computer-aided diagnosis system for diagnosis of lung disorders, namely, bronchiectasis, tuberculosis, and pneumonia. An accuracy of 97.37 % has been achieved by the proposed approach whereas the conventional thresholding approach was unable to detect peripheral pathology-bearing regions. The results obtained prove to be better than that achieved using conventional thresholding and morphological operations. 相似文献
25.
26.
The increasing occurrence of antibiotic-resistant bacteria combined with regulatory pressure and consumer demands for foods produced without antibiotics has caused the agricultural industry to restrict its practice of using antibiotic growth promoters (AGP) in food animals. The poultry industry is not immune to this trend, and has been actively seeking natural alternatives to AGP that will improve the health and growth performance of commercial poultry flocks. Bacillus probiotics have been gaining in popularity in recent years as an AGP alternative because of their health-promoting benefits and ability to survive the harsh manufacturing conditions of chicken feed production. This review provides an overview of several modes of action of some Bacillus direct-fed microbials as probiotics. Among the benefits of these direct-fed microbials are their production of naturally synthesized antimicrobial peptides, gut flora modulation to promote beneficial microbiota along the gastrointestinal tract, and various immunological and gut morphological alterations. The modes of action for increased performance are not well defined, and growth promotion is not equal across all Bacillus species or within strains. Appropriate screening and characterization of Bacillus isolates prior to commercialization are necessary to maximize poultry growth to meet the ultimate goal of eliminating AGP usage in animal husbandry. 相似文献
27.
28.
29.
30.