全文获取类型
收费全文 | 1397篇 |
免费 | 97篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 60篇 |
妇产科学 | 54篇 |
基础医学 | 117篇 |
口腔科学 | 12篇 |
临床医学 | 138篇 |
内科学 | 425篇 |
皮肤病学 | 21篇 |
神经病学 | 29篇 |
特种医学 | 101篇 |
外科学 | 90篇 |
综合类 | 30篇 |
一般理论 | 2篇 |
预防医学 | 251篇 |
眼科学 | 8篇 |
药学 | 37篇 |
肿瘤学 | 116篇 |
出版年
2021年 | 19篇 |
2020年 | 11篇 |
2019年 | 8篇 |
2018年 | 18篇 |
2017年 | 20篇 |
2016年 | 18篇 |
2015年 | 23篇 |
2014年 | 38篇 |
2013年 | 73篇 |
2012年 | 42篇 |
2011年 | 49篇 |
2010年 | 61篇 |
2009年 | 37篇 |
2008年 | 50篇 |
2007年 | 47篇 |
2006年 | 51篇 |
2005年 | 52篇 |
2004年 | 47篇 |
2003年 | 27篇 |
2002年 | 35篇 |
2001年 | 47篇 |
2000年 | 33篇 |
1999年 | 35篇 |
1998年 | 33篇 |
1997年 | 43篇 |
1996年 | 35篇 |
1995年 | 27篇 |
1994年 | 26篇 |
1993年 | 18篇 |
1992年 | 36篇 |
1991年 | 24篇 |
1990年 | 26篇 |
1989年 | 34篇 |
1988年 | 30篇 |
1987年 | 36篇 |
1986年 | 36篇 |
1985年 | 30篇 |
1984年 | 23篇 |
1983年 | 16篇 |
1982年 | 18篇 |
1981年 | 11篇 |
1980年 | 13篇 |
1979年 | 22篇 |
1978年 | 17篇 |
1977年 | 13篇 |
1976年 | 15篇 |
1975年 | 10篇 |
1974年 | 10篇 |
1971年 | 9篇 |
1970年 | 7篇 |
排序方式: 共有1499条查询结果,搜索用时 15 毫秒
41.
Corticosteroids have the ability to suppress the production of growth factors and cytokines and are thus implicated in the negative regulation of hematopoiesis. We have shown that the corticosteroids, prednisolone and dexamethasone, were able to effectively protect progenitor cells in four strains of mice against cell-cycle-specific antimetabolic chemotherapy agents. The highest levels of protection against 5-fluorouracil (FU; 200 mg/kg) were achieved when two or three intraperitoneal injections of dexamethasone were administered between - 7 and +3 hours at a dose of 7.5 mg/kg/injection (optimal dose) or by continuous infusion between -4 and +20 hours. This protective effect is manifested as an increase in the number of high proliferative potential colony-forming cells that survive in the bone marrow 3 days after treatment with FU from between 0.5% and 11% to between 10% and 34% of normal. The bone marrow progenitors and blood cell numbers return to normal from 3 to 5 days and 1 to 2 days earlier, respectively. Less dexamethasone than prednisolone is required to give an equivalent protective effect, which is consistent with their anti-inflammatory potency. These findings are further evidence of the negative regulatory role played by corticosteroids, and indicate that the treatment schedules of corticosteroids during cancer therapy need to be reexamined to obtain the maximum benefit from their use. 相似文献
42.
Dr. Elaine B. Feldman MD Regina Watt AB Daniel S. Feldman MD 《Digestive diseases and sciences》1977,22(5):415-418
Effects of bile salts on intestinal glucose transfer differ in diverse animal preparations exposed to various bile acids. Radiolabeled glucose influx into rat jejunum in vitro was studied in buffer and compared to taurodeoxycholate, taurochenodeoxycholate, taurocholate, and deoxycholate. Jejunum was obtained from intact, bile-diverted, and colestipoltreated rats and in similar categories after abdominal x-irradiation. Taurodeoxycholate but not taurocholate inhibited glucose influx only in bile-fistula and colestipol-treated rats. Bile diversion increased and colestipol decreased glucose uptake from buffer. Added inhibitory effects of irradiation and bile salts were seen in bile-fistula animals. These data suggest that normal exposure to bile is chronically inhibiting jejunal glucose transport and that dihydroxy bile salts are responsible for this effect. They do not provide an explanation for the role of bile in the intestinal radiation syndrome.This work was supported in part by contract No. AT-(40-1) 3882 from the U.S. Atomic Energy Commission.These data were presented in part at the annual meeting of the Southern Society for Clinical Investigation, New Orleans, La. February, 1975. 相似文献
43.
44.
45.
46.
Costan G. Magnussen Juha Koskinen Markus Juonala Wei Chen Sathanur R. Srinivasan Matthew A. Sabin Russell Thomson Michael D. Schmidt Quoc Manh Nguyen Ji-Hua Xu Michael R. Skilton Mika Kähönen Tomi Laitinen Leena Taittonen Terho Lehtimäki Tapani Rönnemaa Jorma S.A. Viikari Gerald S. Berenson Olli T. Raitakari 《Journal of the American College of Cardiology》2012
47.
Stress Mediates the Relationship Between Past Drug Addiction and Current Risky Sexual Behaviour Among Low‐income Women 下载免费PDF全文
Z. Helen Wu Howard Tennen G. M. Monawar Hosain Emil Coman Jerry Cullum Abbey B. Berenson 《Stress and health》2016,32(2):138-144
This study examined the role of stress as a mediator of the relationship between prior drug addiction and current high‐risk sexual behaviour. Eight hundred twenty women aged 18 to 30 years, who received care at community‐based family planning clinics, were interviewed using the Composite International Diagnostic Interview and the Sexual Risk Behavior Assessment Schedule. They also completed the brief version of the Self‐Control Scale as a measure of problem‐solving strategies and measures of recent stressful events, daily hassles and ongoing chronic stress. Regardless of addiction history, stress exposure during the previous 12 months was associated with risky sexual behaviour during the previous 12 months. Structural equation modelling revealed that 12‐month stress levels mediated the relationship between past drug addiction and 12‐month high‐risk sexual behaviours, as well as the negative relationship between problem‐solving strategies and high‐risk sexual behaviours. Problem‐solving strategies did not moderate the relationship between drug addiction and high‐risk sexual behaviours. These findings suggest that stress management training may help reduce risky behaviour among young, low‐income women Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
48.
49.
50.