全文获取类型
收费全文 | 303篇 |
免费 | 29篇 |
国内免费 | 29篇 |
专业分类
儿科学 | 13篇 |
妇产科学 | 1篇 |
基础医学 | 17篇 |
口腔科学 | 25篇 |
临床医学 | 40篇 |
内科学 | 61篇 |
皮肤病学 | 8篇 |
神经病学 | 18篇 |
特种医学 | 112篇 |
外科学 | 9篇 |
综合类 | 22篇 |
预防医学 | 3篇 |
药学 | 22篇 |
肿瘤学 | 10篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 1篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 6篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 6篇 |
2009年 | 11篇 |
2008年 | 5篇 |
2007年 | 14篇 |
2006年 | 5篇 |
2005年 | 15篇 |
2004年 | 2篇 |
2003年 | 5篇 |
2002年 | 8篇 |
2001年 | 7篇 |
2000年 | 2篇 |
1999年 | 6篇 |
1998年 | 21篇 |
1997年 | 25篇 |
1996年 | 21篇 |
1995年 | 8篇 |
1994年 | 24篇 |
1993年 | 23篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 17篇 |
1988年 | 12篇 |
1987年 | 10篇 |
1986年 | 4篇 |
1985年 | 12篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 12篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 5篇 |
排序方式: 共有361条查询结果,搜索用时 0 毫秒
101.
Snyder DS; Chao NJ; Amylon MD; Taguchi J; Long GD; Negrin RS; Nademanee AP; O'Donnell MR; Schmidt GM; Stein AS 《Blood》1993,82(9):2920-2928
Ninety-nine consecutive patients with acute leukemia in first complete remission under age 50 (median age 27 years; age range 1 to 47 years) with a histocompatible sibling donor were treated with fractionated total body irradiation (1,320 cGy) and high-dose etoposide (60 mg/kg) followed by allogeneic bone marrow transplantation. Sixty-one patients were diagnosed with acute myelogenous leukemia (AML), 34 patients with acute lymphoblastic leukemia (ALL), 3 patients with biphenotypic acute leukemia, and 1 patient with acute undifferentiated leukemia. Thirty of the 34 patients with ALL had at least one of the following high-risk factors: age greater than 30, white blood cell count at presentation > 25,000/microL, extramedullary disease, certain chromosomal translocations, or the need for greater than 4 weeks of induction chemotherapy to achieve first complete remission. Cumulative probabilities of disease-free survival and relapse at 3 years were 61% and 12%, respectively, for the 61 patients with AML and 64% and 12%, respectively, for the 34 patients with ALL. By stepwise Cox regression analysis, significant prognostic variables for patients with acute myelogenous leukemia were the presence of acute graft-versus-host disease and increasing age, whereas for patients with acute lymphoblastic leukemia, significant variables were age and the development of cytomegalovirus-associated interstitial pneumonia. Complications related to graft-versus-host disease and relapse of leukemia were the major causes of death. 相似文献
102.
Background : Why oral health status outside capital cities is poorer than that in capital cities has not been satisfactorily explained. The aim of this study was to determine if the reason was poorer access to dental care. Methods : Data were obtained from the Australian National Survey of Adult Oral Health (2004–06). Oral health status was measured by DMFT Index, and numbers of decayed, missing and filled teeth. A two‐step analysis was undertaken: comparing the dependent variables by location, socio‐demographic confounders and preventive dental behaviours, and then including six access to dental care variables. Results : Of the 14 123 people interviewed, 5505 were examined, and 4170 completed the questionnaire. With socio‐economic parameters in the first regression model, non‐capital city people had higher DMFT (regression coefficient = 1.15, p < 0.01), more decayed (0.42, p < 0.01) and missing teeth (0.85, p < 0.01), but not filled teeth (?0.11, p = 0.71), than capital city based people. In the second step analysis, non‐capital city people still had a greater DMFT (1.01, p < 0.01), more decayed (0.27, p = 0.03) and missing teeth (0.74, p < 0.01), but not filled teeth (0.00, p = 0.99) than capital city based people. Conclusions : Access to dental care was not the only reason why people outside capital cities have poorer oral health than people living in capital cities. 相似文献
103.
104.
Som PM; Dillon WP; Fullerton GD; Zimmerman RA; Rajagopalan B; Marom Z 《Radiology》1989,172(2):515-520
Clinically assessed chronic proteinacious sinonasal secretions usually have long T1 and T2 relaxation times reflecting their high water content. However, in some cases variable combinations of short and long T1 and T2 relaxation times are found. To study the causes of these findings, the magnetic resonance (MR) images of 41 patients with surgically proved, chronically obstructed sinonasal secretions were studied. The relative signal intensities on both T1- and T2-weighted sequences of the sinus specimens were correlated with the gross viscosity of the specimens at surgery. Ten specimens were collected that were not contaminated with either blood or saline. UV spectrophotometric analysis of four of these samples excluded the presence of methemoglobin. Total protein content was determined in five samples, and in vitro T1 and T2 values were measured in one sample. These T1 and T2 relaxation times were accurately predicted with use of a standard pure lysozyme protein solution with the same concentration as the specimen. In addition, the observed T1- and T2-weighted signal intensities on the 41 MR images were predicted from an analysis of pure protein solutions. This study concludes that the primary causes of the variable T1 and T2 relaxation times of chronic sinonasal secretions are the macromolecular protein concentration, the amount of free water, and the specimen viscosity. Furthermore, an orderly and predictable transition of these signal intensities occurs over time. 相似文献
105.
2,4-二氨基-5-甲基-6-取代苄氨基喹唑啉衍生物的合成及其抗疟和抗肿瘤作用 总被引:2,自引:0,他引:2
本文报道2,4-二氨基-5-甲基-6-取代苄氨基喹唑啉衍生物的合成及其抗疟和抗肿瘤活性。这类化合物由5-甲基-2,4,6-三氨基喹唑啉与相应的取代苯甲醛缩合成Schiff碱,然后经还原,甲酰化或亚硝化制得。经对伯氏鼠疟原虫(Plasmodium berghei)抑制性治疗筛选,有三个化合物Ⅳ_(2,5,6)剂量5mg/kg×4d抑制率为100%;体外抗肿瘤活性以Ⅱ_7和Ⅳ_8最强,对L1210白血病细胞株的IC_(50)分别为3.910×10~(-3)μg/ml和6.172×10~(-3)μg/ml,与MTX相当。 相似文献
106.
107.
108.
P Modi H Imura M Caputo AJ Parry A Pawade M-S Suleiman GD Angelini . 《Journal of cardiac surgery》2002,17(6):561-561
Aim: Ventricular septal defect(VSD) is the most frequently congenital heart disease. Some patients with VSD are accompanied by mitral insufficiency (MI). The post-operative MI is a much more important cause resulting in congestive heart failure. But it is still unclear whether MI will disappeared after VSD closure procedure. The purpose is to study the relationship between early VSD closure and the post-operative MI. Methods: 295 cases with VSD, MI were chosen for study from Feb. 1990 to Feb. 1998. Patients aged from 10 day to 12 year old, mean age was 2.6 year old. There were 223 patients with congestive heart failure(CHF). Results: MI was related to the severity of CHF, the more severe MI, the more severe CHF. The more large size VSD and left to right shunt, the more severe MI. 126 patients were performed surgical VSD close and 169 patients received medicine therapy including digoxin and captopril. There are no significant differences between two groups in age, sex, sevirity of MI before surgery. The follow-up period varied from 6 months to 34 months. After surgical VSD closure, MI disappeared in 99 patients, diminished in 5 patients, MI unchanged in 22 patients. After medicine therapy, MI disappeared in 69 patients, diminished in 13 patients, unchanged in 83 patients, and deteriorated in 12 patients. Conclusion: After surgical VSD closure in patients with VSD, MI, MI in most patients disappeared or diminished, but MI disappeared or diminished only in about half patients without surgical VSD closure, MI remained unchanged in a half patients and even worse in 12 patients. So early VSD closure is necessary for patients with VSD, MI. 相似文献
109.
110.