全文获取类型
收费全文 | 1871篇 |
免费 | 126篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 66篇 |
妇产科学 | 30篇 |
基础医学 | 231篇 |
口腔科学 | 55篇 |
临床医学 | 146篇 |
内科学 | 399篇 |
皮肤病学 | 40篇 |
神经病学 | 72篇 |
特种医学 | 158篇 |
外科学 | 260篇 |
综合类 | 37篇 |
预防医学 | 119篇 |
眼科学 | 82篇 |
药学 | 101篇 |
中国医学 | 4篇 |
肿瘤学 | 218篇 |
出版年
2023年 | 12篇 |
2022年 | 33篇 |
2021年 | 70篇 |
2020年 | 41篇 |
2019年 | 44篇 |
2018年 | 39篇 |
2017年 | 39篇 |
2016年 | 38篇 |
2015年 | 42篇 |
2014年 | 82篇 |
2013年 | 88篇 |
2012年 | 97篇 |
2011年 | 101篇 |
2010年 | 83篇 |
2009年 | 81篇 |
2008年 | 110篇 |
2007年 | 123篇 |
2006年 | 72篇 |
2005年 | 84篇 |
2004年 | 60篇 |
2003年 | 67篇 |
2002年 | 41篇 |
2001年 | 34篇 |
2000年 | 32篇 |
1999年 | 42篇 |
1998年 | 45篇 |
1997年 | 46篇 |
1996年 | 41篇 |
1995年 | 21篇 |
1994年 | 20篇 |
1993年 | 21篇 |
1992年 | 10篇 |
1991年 | 13篇 |
1990年 | 19篇 |
1989年 | 28篇 |
1988年 | 22篇 |
1987年 | 17篇 |
1986年 | 23篇 |
1985年 | 20篇 |
1984年 | 11篇 |
1983年 | 16篇 |
1982年 | 12篇 |
1981年 | 5篇 |
1980年 | 14篇 |
1978年 | 5篇 |
1977年 | 9篇 |
1976年 | 10篇 |
1975年 | 5篇 |
1969年 | 6篇 |
1968年 | 4篇 |
排序方式: 共有2025条查询结果,搜索用时 31 毫秒
101.
102.
103.
104.
Waterston–Cooley anastomosis may be carried out in patients with tricuspid atresia to provide pulmonary perfusion. It is associated with several complications, including preferential blood flow to the right lung, hypoplasia of the left pulmonary artery, obstruction of the anatomosis or rupture of pulmonary aneurysms. We study a patient with thrombosis in the pulmonary arteries following surgical construction of a Waterston shunt in childhood. Imaging findings and clinical symptoms are discussed with emphasis on echocardiogram‐gated multislice spiral CT. 相似文献
105.
Guillermo Garcia-Manero Carlos Bueso-Ramos Jerry Daniel Jason Williamson Hagop M Kantarjian Jean-Pierre J Issa 《Clinical cancer research》2002,8(6):1897-1903
PURPOSE: Aberrant DNA methylation of promoter-associated CpG islands is an epigenetic DNA modification observed in acute leukemias that in certain cases has been associated with a poor prognosis and increased relapse rates. To study the role of DNA methylation in relapse mechanisms in acute lymphocytic leukemia (ALL), we have compared the methylation status of five genes at the time of initial presentation and at first relapse in 25 adult patients with ALL. EXPERIMENTAL DESIGN: Genes studied included the estrogen receptor (ER), multidrug resistance gene 1 (MDR1), p73, p15, and p16. DNA was extracted from paraffin-embedded bone marrow biopsies. DNA methylation was analyzed using PCR of bisulfite-modified DNA. RESULTS: Results indicate that methylation at the time of relapse was stable in 92% of patients for p73, 88% for ER, 80% for p16, 72% for MDR1, and 60% for p15. Only one case had p16 methylation at initial presentation, whereas 6 patients (P = 0.0001) had methylation at relapse. Three cases had concomitant methylation of p15 and p16 at relapse. The degree of MDR1 methylation inversely correlated with the presence of MDR1 expression as detected by immunohistochemistry. Eighteen patients (72%) had acquired no or one methylation change, whereas the rest (28%) had methylation changes in two or three genes. No clinical-biological correlations were found between methylation of any particular gene or pattern. CONCLUSIONS: In summary, DNA methylation patterns are stable in a majority of patients with relapsed ALL, but a subset of patients acquire new methylation changes, in particular affecting cell cycle regulatory genes. 相似文献
106.
Existing bonding systems permit effective bonding to enamel or dentine. Bonding to dentine is mainly achieved through the hybridization of dentine with resin. However, despite their success, the 'three-bottle' systems do have drawbacks--the large number of steps involved may be confusing and prone to errors of application, as well as being time consuming. Recently developed systems have significantly reduced the number of steps and the total treatment time, but deliver a reliable outcome. 相似文献
107.
108.
The relationship between the insulin-breakfast interval, postprandial increase in blood glucose, and glycaemic control was studied in 58 children with diabetes. Patients recorded insulin-breakfast intervals in a home diary over a seven day period, and during a 24 hour period at the weekend provided eight serial capillary dried blood spots for glucose analysis. The highest mean blood glucose value occurred two hours after breakfast and showed a significant correlation with fructosamine concentrations. Weekend insulin-breakfast intervals ranged from 2-30 minutes, with 70% reporting intervals of less than 15 minutes. There was a significant correlation between the weekend insulin-breakfast interval and the after breakfast increase in blood glucose with a mean increment of 0.4 mmol/l in the 30 minute group and 7.2 mmol/l in the 2 minute group. Over the whole study period, children with mean insulin-breakfast intervals of two to 12 minutes had a mean fructosamine concentration of 376 mumol/l compared with 341 mumol/l in those with intervals of 15-35 minutes. This study has shown that the interval between insulin injection and breakfast significantly influences the morning postprandial rise in blood glucose and consequently short term glycaemic control. It is therefore important that patients are encouraged to leave an interval of about 30 minutes between insulin injection and breakfast. 相似文献
109.
Toyota M Shen L Ohe-Toyota M Hamilton SR Sinicrope FA Issa JP 《Cancer research》2000,60(15):4044-4048
110.