全文获取类型
收费全文 | 1184篇 |
免费 | 192篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 55篇 |
妇产科学 | 27篇 |
基础医学 | 59篇 |
口腔科学 | 12篇 |
临床医学 | 188篇 |
内科学 | 305篇 |
皮肤病学 | 32篇 |
神经病学 | 67篇 |
特种医学 | 80篇 |
外科学 | 246篇 |
综合类 | 48篇 |
现状与发展 | 20篇 |
预防医学 | 102篇 |
眼科学 | 29篇 |
药学 | 53篇 |
中国医学 | 2篇 |
肿瘤学 | 57篇 |
出版年
2024年 | 7篇 |
2023年 | 43篇 |
2021年 | 23篇 |
2020年 | 23篇 |
2019年 | 15篇 |
2018年 | 57篇 |
2017年 | 50篇 |
2016年 | 39篇 |
2015年 | 53篇 |
2014年 | 47篇 |
2013年 | 62篇 |
2012年 | 34篇 |
2011年 | 47篇 |
2010年 | 53篇 |
2009年 | 70篇 |
2008年 | 46篇 |
2007年 | 41篇 |
2006年 | 45篇 |
2005年 | 27篇 |
2004年 | 26篇 |
2003年 | 25篇 |
2002年 | 23篇 |
2001年 | 20篇 |
2000年 | 17篇 |
1999年 | 21篇 |
1998年 | 30篇 |
1997年 | 33篇 |
1996年 | 45篇 |
1995年 | 32篇 |
1994年 | 20篇 |
1993年 | 22篇 |
1992年 | 18篇 |
1991年 | 16篇 |
1990年 | 19篇 |
1989年 | 17篇 |
1988年 | 24篇 |
1987年 | 20篇 |
1986年 | 18篇 |
1985年 | 22篇 |
1984年 | 10篇 |
1983年 | 6篇 |
1982年 | 11篇 |
1980年 | 6篇 |
1979年 | 8篇 |
1978年 | 16篇 |
1977年 | 16篇 |
1976年 | 13篇 |
1975年 | 8篇 |
1973年 | 5篇 |
1964年 | 5篇 |
排序方式: 共有1395条查询结果,搜索用时 11 毫秒
1.
V Aerra M Kuduvalli AN Moloto AK Srinivasan AD Grayson BM Fabri AY Oo 《Journal of cardiothoracic surgery》2006,1(1):6-5
Background
Atrial fibrillation can occur in up to 40% of patients undergoing coronary surgery. 相似文献2.
Paul Wexberg MD BM Richard Pacher MD Suzanne Rdler MD Katharina Kiss MD Gilbert Beran MD Michael Grimm MD Gerald Maurer MD Dietmar Glogar MD FESC 《The Journal of heart and lung transplantation》2002,21(12):583-1263
BACKGROUND: Endothelin, a peptide with strong vasoconstrictive and mitogenic properties, has been found to increase after cardiac transplantation. We therefore assessed the association between its precursor peptide, big endothelin-1, and intimal hyperplasia and coronary flow reserve after heart transplantation. METHODS: Thirty-five patients without hemodynamically significant coronary artery disease after heart transplantation were investigated: Average peak flow velocity in the left anterior descending artery (LAD) was assessed by intracoronary Doppler at baseline as well as after injection of adenosine; coronary flow reserve was calculated as a ratio of both and was corrected for patient age and baseline average peak flow velocity. Lumen, intima + media and total vessel area were measured by intracoronary ultrasound. The plasma concentration of big endothelin-1 in venous blood was determined by radioimmunoassay. RESULTS: Patients with elevated big endothelin-1 levels (>2 fmol/ml) tended to have a decreased corrected coronary flow reserve (2.60 +/- 0.9 vs 3.21 +/- 1.0, p = 0.078). They also had a significantly larger intima + media area (5.82 +/- 2.9 vs 2.37 +/- 2.9 mm(2), p = 0.004) and total vessel area (18.36 +/- 5.8 vs 12.81 +/- 4.8 mm(2), p = 0.012) than those with normal plasma concentrations. CONCLUSIONS: Our study suggests an association between elevated big endothelin-1 plasma levels and the development of intimal hyperplasia and reduction of coronary flow reserve after cardiac transplantation. 相似文献
3.
4.
Sigmund Jenssen Michael R. Sperling Joseph I. Tracy Maromi Nei Liporace Joyce Glosser David Michael OConnor 《Seizure》2006,15(8):621-629
RATIONALE: A small percentage of patients with idiopathic generalized epilepsy (IGE) do not respond to medical therapy. Generalized tonic-clonic (GTC) seizures are especially debilitating and can be associated with severe injuries. The benefit, safety and effect of corpus callosotomy (CC) in patients with IGE have not been studied. METHODS: We reviewed patients with presumed IGE who underwent CC between 1991 and 2000. Criteria for selection included history, examination, brain imagining, interictal and ictal EEG. All patients had refractory and debilitating tonic-clonic seizures (GTCS) and had failed four or more antiepileptic drugs. Seizure frequency was calculated per month over the last year and pre-operative baseline was compared to last follow-up using paired t-tests. IQ, executive function, language and verbal, non-verbal memory and quality of life (QOL) was compared before and after surgery. Serial EEGs after surgery were reviewed. RESULTS: There were nine patients (seven men), mean age 37.9 (range: 22-49), mean IQ 87.3 (range: 75-107). All had anterior CC. Mean follow-up time was 5.4 years (range: 0.6-10.3 years). One patient died from sudden death in epilepsy 9 months after surgery. There was a significant reduction of GTC seizures from 6.3 to 1.1 (p<0.005). Four patients had more than 80% and eight more than 50% reduction. Of five patients with absence seizures, two became seizure free and one had more than 80% reduction and two worsened slightly, and of three with myoclonic seizures one had more than 90% reduction. One patient had completion of the CC with improvement of myoclonus and absence seizures, but not of GTC seizures and suffered a disconnection syndrome. Another had right frontal focal resection without improvement after new seizures of focal onset. Cognitive testing showed a good outcome (improved or no change) in all cognitive domains. Post-surgical EEG showed new focal slowing and sharp waves. There was no change in QOL. CONCLUSION: CC can be effective in reducing GTC, absence and myoclonic seizures in patients with refractory IGE. These findings suggest that interhemispheric communication of the cerebral cortices plays an important role in the generation of seizures in IGE. Anterior CC appears safe while complete callosotomy has a risk of disconnection syndrome. 相似文献
5.
A randomized controlled trial of sedation in the critically ill 总被引:2,自引:0,他引:2
LYNN PARKINSON RSCN JULIE HUGHES RSCN REA GILL MSc IMOGEN BILLINGHAM BM FRCA JANE RATCLIFFE MB ChB FRCP & IMTI CHOONARA MD MRCP 《Paediatric anaesthesia》1997,7(5):405-510
A randomized controlled trial comparing: a) a combination of oral chloral hydrate and promethazine to b) a continuous intravenous midazolam infusion, for maintenance sedation in critically ill children, was carried out. The level of sedation was assessed four hourly using a specifically devized sedation scale. Forty-four children entered the study of whom two were subsequently excluded. The number of satisfactory assessments (desired and actual levels of sedation equal) was significantly greater in the chloral hydrate and promethazine group (Chi-squared P <0.01; confidence intervals of the difference 0.06 to 0.20). The number of assessments at level 5 on the sedation scale (patient restless/distressed) was significantly greater in the midazolam group (Chi-squared P <0.05). The total number of satisfactory assessments in the two groups were only 61 and 48% respectively, suggesting that sedation can be considerably improved. Chloral hydrate and promethazine are more effective than midazolam as maintenance sedation in critically ill children. It is possible to prospectively study the efficacy of sedative drugs in critically ill children. 相似文献
6.
7.
8.
9.
The computerized database system described was initially developed in 1986 to facilitate analysis of retrospective head and neck cancer data from the Royal Adelaide Hospital Department of Otolaryngology. This has now been expanded to become an on-going patient information management system. It is based on the dBase-III-Plus database package and is implemented on an IBM XT compatible computer. The system was designed to be used by staff without specialist computer skills and is therefore largely “menu-driven.” The main functions include patient record creation, update, and retrieval, and the production of reports including graphical presentations. There is also a powerful but easy to use query facility. The system has already provided much useful epidemiological material but is now beginning to fulfill an even more important role in patient follow-up and in assisting evaluation of alternative treatment protocols. 相似文献
10.
This study deals with the role of glutathione transferase (GST)-mediatedconjugation of (+)-7ß,8-dihydroxy-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene(BPDE) in two mammalian cell lines, human mammary carcinomacells (MCF-7) and rat hepatoma cells (H4IIE), in relation tothen-capacity to metabolize ()-trans-7,8-dihydroxy-7,8-dihydro-benzo[a]pyrene[()-BP-7,8-diol] to products that induce mutations inco-cultivated V79 cells. Both MCF-7 and H4IIE cells metabolized()-BP-7,8-diol to BPDE, but mutations in co-cultivatedV79 cells were only detected with MCF-7 cells. However, depletionof glutathione (GSH) in H4HE cells increased the mutagenidtyof ( )-BP-7,8-diol to a similar level to that found withMCF-7 cells. Measurements of GST activity using GSH and post-microsomalsupernatants from H4IIE, V79 and MCF-7 cells indicated a substantialdifference in conjugation capacity. Although preparations fromall three cell-lines showed GST activity with l-chloro-2,4-dlnitro-benzeneas the substrate, GST activity towards BPDE could only be detectedin supernatants from H4HE cells. This is consistent with thepresence of GST 7-7 an isoenzyme highly efficient hi catalysingBPDE-GSH conjugation. The difference in GSH-conjugation activitytowards BPDE was confirmed using intact H4IIE and MCF-7 cellsin culture. These results indicate that GSH-conjugation playsa pivotal role in mutagenesis induced by polycyclk aromatichydrocarbons (PAH). Accordingly, a deficiency in GSH-conjugationcapacity may be regarded as one important factor in defininga target cell population with an increased risk for tumour initiationfollowing exposure to PAH. 相似文献