全文获取类型
收费全文 | 2420篇 |
免费 | 172篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 112篇 |
妇产科学 | 30篇 |
基础医学 | 299篇 |
口腔科学 | 68篇 |
临床医学 | 224篇 |
内科学 | 444篇 |
皮肤病学 | 38篇 |
神经病学 | 251篇 |
特种医学 | 158篇 |
外科学 | 361篇 |
综合类 | 43篇 |
预防医学 | 224篇 |
眼科学 | 35篇 |
药学 | 148篇 |
肿瘤学 | 164篇 |
出版年
2021年 | 40篇 |
2020年 | 26篇 |
2018年 | 29篇 |
2017年 | 22篇 |
2016年 | 25篇 |
2015年 | 30篇 |
2014年 | 52篇 |
2013年 | 75篇 |
2012年 | 91篇 |
2011年 | 101篇 |
2010年 | 73篇 |
2009年 | 86篇 |
2008年 | 87篇 |
2007年 | 96篇 |
2006年 | 98篇 |
2005年 | 93篇 |
2004年 | 77篇 |
2003年 | 63篇 |
2002年 | 73篇 |
2001年 | 54篇 |
2000年 | 66篇 |
1999年 | 51篇 |
1998年 | 60篇 |
1997年 | 46篇 |
1996年 | 50篇 |
1995年 | 52篇 |
1994年 | 24篇 |
1993年 | 33篇 |
1992年 | 43篇 |
1991年 | 35篇 |
1990年 | 60篇 |
1989年 | 50篇 |
1988年 | 49篇 |
1987年 | 64篇 |
1986年 | 50篇 |
1985年 | 53篇 |
1984年 | 41篇 |
1983年 | 34篇 |
1982年 | 31篇 |
1980年 | 27篇 |
1979年 | 23篇 |
1977年 | 21篇 |
1975年 | 23篇 |
1974年 | 20篇 |
1973年 | 20篇 |
1972年 | 30篇 |
1971年 | 31篇 |
1970年 | 27篇 |
1969年 | 23篇 |
1968年 | 21篇 |
排序方式: 共有2614条查询结果,搜索用时 15 毫秒
1.
Adaptation of the distal convoluted tubule of the rat. Structural and functional effects of dietary salt intake and chronic diuretic infusion. 总被引:3,自引:1,他引:2 下载免费PDF全文
We studied the effects of dietary NaCl intake on the renal distal tubule by feeding rats high or low NaCl chow or by chronically infusing furosemide. Furosemide-treated animals were offered saline as drinking fluid to replace urinary losses. Effects of naCl intake were evaluated using free-flow micropuncture, in vivo microperfusion, and morphometric techniques. Dietary NaCl restriction did not affect NaCl delivery to the early distal tubule but markedly increased the capacity of the distal convoluted tubule to transport Na and Cl. Chronic furosemide infusion increased NaCl delivery to the early distal tubule and also increased the rates of Na and Cl transport above the rates observed in low NaCl diet rats. When compared with high NaCl intake alone, chronic furosemide infusion with saline ingestion increased the fractional volume of distal convoluted tubule cells by nearly 100%, whereas dietary NaCl restriction had no effect. The results are consistent with the hypotheses that (a) chronic NaCl restriction increases the transport ability of the distal convoluted tubule independent of changes in tubule structure, (b) high rates of ion delivery to the distal nephron cause tubule hypertrophy, and (c) tubule hypertrophy is associated with increases in ion transport capacity. They indicate that the distal tubule adapts functionally and structurally to perturbations in dietary Na and Cl intake. 相似文献
2.
3.
R C Flanigan M F Ellison K M Butler L G Gomella J W McRoberts 《The Journal of urology》1986,136(1):35-37
There were 40 consecutive patients with recurrent or multiple superficial stage Ta or T1 transitional cell cancer assigned randomly to receive prophylactic thiotepa or mitomycin C intravesical chemotherapy. Patients received 8 weekly instillations followed by 22 monthly treatments of either 60 mg. thiotepa or 40 mg. mitomycin C. Of 25 patients randomized to receive mitomycin C 4 had recurrence in a total of 337 patient-months (1.19 per 100 patient-months), while disease recurred in 1 of 15 patients randomized to receive thiotepa who were followed for a total of 220 patient-months (0.45 per 100 patient-months). No significant difference in recurrence rate was noted for either drug group (p equals 0.18). Toxicity requiring cessation of therapy was observed in 7 patients (28 per cent) on mitomycin C and none on thiotepa. 相似文献
4.
Peter T Ellison 《American journal of human biology》2005,17(1):113-118
The fetal origins hypothesis, or Barker hypothesis, is both stimulating and challenging for evolutionary human biologists. While evidence of a correlation between conditions around the time of birth and later health outcomes has been presented before, the more recent evidence of a connection between fetal growth and chronic disease risk later in life has attracted considerable attention among epidemiologists and human biologists. Several themes that are fundamental to human biology emerge from an engagement with the fetal origins hypothesis. Among them are the tension between concepts of pathology, constraint, and adaptation; the importance of a life history perspective that embraces the notion of trade-offs; the question of environmental predictability; and the mechanisms of energy mobilization and allocation. Bringing the insights of evolutionary biology to bear on the fetal origins hypothesis illustrates the value of the field now known as evolutionary medicine. 相似文献
5.
6.
7.
8.
9.
Effective haemostasis during cardiac surgery 总被引:2,自引:0,他引:2
10.