全文获取类型
收费全文 | 2039篇 |
免费 | 325篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 103篇 |
妇产科学 | 24篇 |
基础医学 | 142篇 |
口腔科学 | 26篇 |
临床医学 | 303篇 |
内科学 | 665篇 |
皮肤病学 | 61篇 |
神经病学 | 183篇 |
特种医学 | 291篇 |
外科学 | 218篇 |
综合类 | 36篇 |
预防医学 | 73篇 |
眼科学 | 18篇 |
药学 | 75篇 |
中国医学 | 1篇 |
肿瘤学 | 126篇 |
出版年
2023年 | 54篇 |
2022年 | 13篇 |
2021年 | 29篇 |
2020年 | 92篇 |
2019年 | 14篇 |
2018年 | 90篇 |
2017年 | 72篇 |
2016年 | 70篇 |
2015年 | 67篇 |
2014年 | 98篇 |
2013年 | 119篇 |
2012年 | 61篇 |
2011年 | 64篇 |
2010年 | 87篇 |
2009年 | 115篇 |
2008年 | 50篇 |
2007年 | 62篇 |
2006年 | 67篇 |
2005年 | 45篇 |
2004年 | 29篇 |
2003年 | 26篇 |
2002年 | 27篇 |
2001年 | 41篇 |
2000年 | 24篇 |
1999年 | 41篇 |
1998年 | 85篇 |
1997年 | 101篇 |
1996年 | 80篇 |
1995年 | 72篇 |
1994年 | 53篇 |
1993年 | 54篇 |
1992年 | 35篇 |
1991年 | 29篇 |
1990年 | 37篇 |
1989年 | 68篇 |
1988年 | 47篇 |
1987年 | 32篇 |
1986年 | 26篇 |
1985年 | 24篇 |
1984年 | 19篇 |
1983年 | 10篇 |
1982年 | 21篇 |
1981年 | 19篇 |
1980年 | 14篇 |
1979年 | 14篇 |
1978年 | 11篇 |
1977年 | 10篇 |
1976年 | 16篇 |
1975年 | 7篇 |
1971年 | 9篇 |
排序方式: 共有2404条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
The Medical Research Council UKALL V trial for children with standard-risk acute lymphoblastic leukemia (ALL) (aged 1 to 14 years, leucocyte count less than 20 X 10(9)/L) was designed to determine whether the immunosuppressive effects of treatment could be reduced without sacrifice of antileukemic effect by alterations in the type of continuing therapy or in fractionation of cranial irradiation. Remission was achieved in 496 children on standard induction therapy, and 309 children received 24 Gy of cranial irradiation in ten to 16 fractions over 21 days, and 174 received 21 Gy in five to nine fractions over 21 days. The type of radiotherapy administered had no influence on relapse at any site or rate of death in remission. All 496 children were randomized to receive chemotherapy for 2 or 3 years with 6-mercaptopurine and methotrexate either as a continuous (group C) or a semicontinuous (group G) regimen or as a five-day pulse every 3 weeks (group I). All groups also received vincristine and prednisolone every 6 weeks. With a minimum follow-up of almost 7 years, patients in group I had significantly fewer remission deaths (P = .025) but a much higher rate of bone marrow relapse than those in group C or G (P = .002). There was an overall benefit for 3 years of chemotherapy compared with 2 years, which in contrast to previous studies, was more apparent in girls and in patients in groups C and G. Testicular relapse occurred in 37 boys, including 19 patients off therapy, with a previously negative biopsy. The overall results confirmed the prognostic significance of initial leucocyte count, even among these standard-risk patients, while girls had a superior rate of disease-free survival, but not of hematologic remission. It is concluded that, even among standard-risk patients, the prognosis is influenced by the height of the initial leukocyte count. While alterations in the fractionation of cranial irradiation do not appear to have influenced disease-free survival, intermittent continuing chemotherapy, although less immunosuppressive, is less effective than conventional continuous therapy in the treatment of ALL. In this study, 3 years of chemotherapy appeared superior to 2 years. 相似文献
6.
7.
8.
9.
筛检对肝癌死亡率影响的研究 总被引:5,自引:0,他引:5
5581名HBsAg阳性的男性随机分入周期性筛检组(A组,3712人)及对照组(B组,1869人)。A组(19155.4人年)共发生肝癌257例,B组(9785.5人年)为117例,两组的肝癌发生率分别为1342/10万与1196/10万;两组肝癌死亡分别为218与109例,肝癌死亡率分别为1138/10万与1114/10万。两组中Ⅰ期肝癌病例分别为29.6%与6.0%,差异有非常显著性意义。1、3、5年相对生存率A组为23.7%、7.0%、4.0%,B组为9.7%、4.0%、4.1%。用Poisson回归模型拟合显示,在调正年龄、初筛AFP及入列年份后,筛检对于肝癌的相对危险度为0.83,95%CI为0.68~1.03,有较弱的“保护”作用,Cox回归模型拟合结果显示当临床分期未引入模型时,筛检对于肝癌有显著的“保护”作用:危险率为0.6617,95%CI为0.5234~0.8365;而模型经调整后,危险率即接近“1”,95%CI为0.74~1.26。 相似文献
10.
Ralls PW; Johnson MB; Kanel G; Dobalian DM; Colletti PM; Boswell WD Jr; Radin DR; Halls JM 《Radiology》1986,161(2):451-454
FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease. 相似文献