全文获取类型
收费全文 | 593篇 |
免费 | 39篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 51篇 |
妇产科学 | 12篇 |
基础医学 | 49篇 |
口腔科学 | 33篇 |
临床医学 | 54篇 |
内科学 | 117篇 |
皮肤病学 | 17篇 |
神经病学 | 20篇 |
特种医学 | 102篇 |
外科学 | 62篇 |
综合类 | 25篇 |
预防医学 | 29篇 |
眼科学 | 4篇 |
药学 | 45篇 |
中国医学 | 1篇 |
肿瘤学 | 16篇 |
出版年
2022年 | 1篇 |
2021年 | 17篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 9篇 |
2017年 | 4篇 |
2016年 | 13篇 |
2015年 | 10篇 |
2014年 | 13篇 |
2013年 | 34篇 |
2012年 | 33篇 |
2011年 | 15篇 |
2010年 | 27篇 |
2009年 | 28篇 |
2008年 | 15篇 |
2007年 | 10篇 |
2006年 | 22篇 |
2005年 | 13篇 |
2004年 | 10篇 |
2003年 | 14篇 |
2002年 | 10篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 19篇 |
1998年 | 35篇 |
1997年 | 25篇 |
1996年 | 21篇 |
1995年 | 14篇 |
1994年 | 22篇 |
1993年 | 23篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 13篇 |
1988年 | 16篇 |
1987年 | 9篇 |
1986年 | 15篇 |
1985年 | 7篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 9篇 |
1981年 | 12篇 |
1980年 | 12篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 9篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1957年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有639条查询结果,搜索用时 15 毫秒
41.
To determine the cost of expanding blood product operations, the concept of marginal cost must be used. This article reports the development and implementation of a method of costing increases in collecting plasma using apheresis operations. The model takes into account the fact that certain resource inputs--notably, direct labor and machines--increase in discrete steps rather than in a continuous manner. To address this fact, a stepwise cost analysis function was developed, which related operating costs to the volume of apheresis collections. This function was used to predict the marginal costs of potential increases in the supply of plasma at a blood center in Canada. Differences were noted in the cost of plasma in Canada and the United States, much of which could be attributed to different standards regarding the volume of plasma per collection and to differences in pricing materials. 相似文献
42.
43.
LD Petz ; L Calhoun ; P Yam ; M Cecka ; G Schiller ; AR Faitlowicz ; R Herron ; D Sayah ; RB Wallace ; A Belldegrun 《Transfusion》1993,33(9):742-750
A patient without evident immune deficiency who received a transfusion of blood from a second-degree family member developed fatal transfusion- associated graft-versus-host disease (TA-GVHD). The donor was homozygous for an HLA haplotype for which the recipient was heterozygous (one-way HLA match). All 39 reported cases of TA-GVHD in immunocompetent patients were reviewed to ascertain the predisposing factors and to define the indications for irradiating blood for this population. HLA typing was described in 15 cases; in 13, including seven related and six unrelated donors, a one-way HLA match was present. Thirty-one (79%) of the 39 cases were reported from Japan (and 196 other cases are cited in the Japanese literature), but a one-way HLA match among unrelated donors at HLA-A, -B, -DR loci is only approximately two to four times more likely in Japanese persons than in whites. Fresh blood (< 96 hours old) was used in 29 (94%) of the 31 cases reported from Japan and in 33 (87%) of 38 cases overall (in one case, the age of the blood used was not reported). Thus, factors that appear to predispose to TA-GVHD in immunocompetent patients are a one- way HLA match, fresh blood, and, possibly, Japanese ancestry. Irradiating cellular blood components from all blood relatives of transfusion recipients will not completely eliminate the risk of TA- GVHD. 相似文献
44.
DANIELE M FENSTERSEIFER CRISTINA KAROHL PAULO SCHVARTZMAN CÉSAR AR COSTA FRANCISCO JV VERONESE 《Nephrology (Carlton, Vic.)》2009,14(2):164-170
Aim: Coronary artery calcification (CAC) has been associated with higher mortality in chronic renal disease. The purpose of this study was to assess coronary artery calcium score (CaCs) in haemodialysis patients and to correlate calcium scores with clinical parameters and mortality.
Methods: A cross-sectional study was conducted in 59 haemodialysis patients. CaCs was assessed by multidetector-row computed tomography and stratified as: CaCs of less than 10 Agatston units (U), no calcification; CaCs of 10–400 U, mild-to-moderate; and CaCs of more than 400 U, severe calcification. The effects of age, haemodialysis duration and biochemical and inflammatory markers on CaCs logarithm were evaluated by multiple linear regression analysis. Cox regression analysis was used to measure the impact of CaCs of more than 400 on 2-year mortality.
Results: Coronary calcifications were detected in 64.5% of patients, and the median of CaCs was 31.7 U (0–589.7) with a range of 0–5790.0 U. Twenty-one (35.5%) patients had mild-to-moderate and 17 (29%) severe CaCs. Patients with severe CaCs were older and showed a higher prevalence of ischaemic heart disease and a higher body mass index ( P = 0.04). A trend towards higher C-reactive protein levels was found in patients with severe CaCs. Advanced age was the only variable that influenced CaCs logarithm independently. The effect of severe CaCs on 2-year mortality did not persist after adjustment for other covariates.
Conclusion: Coronary calcification was highly prevalent in these uraemic patients on chronic haemodialysis. A correlation was evidenced between CaCs and advanced age, but severity of the CAC score did not have an impact on 2-year mortality of this cohort. 相似文献
Methods: A cross-sectional study was conducted in 59 haemodialysis patients. CaCs was assessed by multidetector-row computed tomography and stratified as: CaCs of less than 10 Agatston units (U), no calcification; CaCs of 10–400 U, mild-to-moderate; and CaCs of more than 400 U, severe calcification. The effects of age, haemodialysis duration and biochemical and inflammatory markers on CaCs logarithm were evaluated by multiple linear regression analysis. Cox regression analysis was used to measure the impact of CaCs of more than 400 on 2-year mortality.
Results: Coronary calcifications were detected in 64.5% of patients, and the median of CaCs was 31.7 U (0–589.7) with a range of 0–5790.0 U. Twenty-one (35.5%) patients had mild-to-moderate and 17 (29%) severe CaCs. Patients with severe CaCs were older and showed a higher prevalence of ischaemic heart disease and a higher body mass index ( P = 0.04). A trend towards higher C-reactive protein levels was found in patients with severe CaCs. Advanced age was the only variable that influenced CaCs logarithm independently. The effect of severe CaCs on 2-year mortality did not persist after adjustment for other covariates.
Conclusion: Coronary calcification was highly prevalent in these uraemic patients on chronic haemodialysis. A correlation was evidenced between CaCs and advanced age, but severity of the CAC score did not have an impact on 2-year mortality of this cohort. 相似文献
45.
Oral Diseases (2010) 16 , 160–166 Objective: The aim of this comparative study was to analyze cytopathologically and chemico‐physically the mucosa surrounding oral piercing to correlate results with adverse tissue signs. Materials and methods: The tongue superficial mucosa of 15 young subjects (control group) and the superficial mucosa surrounding oral piercing of 15 young subjects (test group, TG) were smeared on slides, Papanicolaou stained and analyzed under the optical microscope. Some smears were prepared for (back‐scattered) scanning electron microscope (SEM) and X‐ray microanalysis to study piercing fragments. Results: Smears of TG displayed a variable extent of bacterial cytolysis of epithelial cells, fungi, hyperkeratosis, parakeratosis, granulocyte infiltration, calcium formations and bacterial flora; the four last statistically significant (P < 0.05). Foreign bodies surrounded by keratinocytes were detected under both light and SEM. X‐ray microanalyses highlighted piercing alloy aggression, ion release and an inverse gradient of ion concentration inside keratinocytes. Conclusions: The pathological findings in smears correlated with adverse effects of oral piercing. Ion release may be related to direct toxic effects and belated reactions because of metal sensitization. A strict regulation of piercing is warranted. 相似文献
46.
47.
48.
49.
Complementary medicine: use and attitudes among GPs 总被引:9,自引:0,他引:9
BACKGROUND: Information about use and attitudes of GPs towards
complementary medicine is required in order to inform the debate about its
place within mainstream medicine. There is evidence that public use of
complementary medicine is particularly high in the South-West of England.
OBJECTIVE: This study aimed to determine the use of, and attitudes towards,
complementary medicine among GPs. METHODS: A questionnaire survey was
performed of all primary care physicians working in the health service in
Devon and Cornwall. RESULTS: Replies were received from 461 GPs, a response
rate of 47%. A total of 314 GPs (68%, range 32-85%) had been involved in
complementary medicine in some way during the previous week. One or other
form of complementary medicine was practised by 74 of the respondents
(16%), the two most common being homoeopathy (5.9%) and acupuncture (4.3%).
In addition, 115 of the respondents (25%) had referred at least one patient
to a complementary therapist in the previous week, and 253 (55%) had
endorsed or recommended treatment with complementary medicine.
Chiropractic, acupuncture and osteopathy were rated as the three most
effective therapies, and the majority of respondents believed that these
three therapies should be funded by the health service. A total of 176
(38%) of respondents reported adverse effects, most commonly after
manipulation. CONCLUSION: Over two-thirds of the GPs in Devon and Cornwall
who responded to the survey had been involved with complementary medicine
in some way during the previous week. This figure is higher than the
national average. The majority of respondents believed that acupuncture,
chiropractic and osteopathy were effective and should be funded by the NHS.
相似文献
50.