全文获取类型
收费全文 | 1459篇 |
免费 | 81篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 121篇 |
妇产科学 | 30篇 |
基础医学 | 209篇 |
口腔科学 | 21篇 |
临床医学 | 121篇 |
内科学 | 267篇 |
皮肤病学 | 16篇 |
神经病学 | 73篇 |
特种医学 | 25篇 |
外科学 | 218篇 |
综合类 | 52篇 |
一般理论 | 3篇 |
预防医学 | 82篇 |
眼科学 | 53篇 |
药学 | 152篇 |
中国医学 | 12篇 |
肿瘤学 | 64篇 |
出版年
2023年 | 14篇 |
2022年 | 39篇 |
2021年 | 55篇 |
2020年 | 34篇 |
2019年 | 42篇 |
2018年 | 50篇 |
2017年 | 37篇 |
2016年 | 35篇 |
2015年 | 44篇 |
2014年 | 51篇 |
2013年 | 73篇 |
2012年 | 62篇 |
2011年 | 70篇 |
2010年 | 51篇 |
2009年 | 48篇 |
2008年 | 69篇 |
2007年 | 70篇 |
2006年 | 74篇 |
2005年 | 81篇 |
2004年 | 70篇 |
2003年 | 49篇 |
2002年 | 50篇 |
2001年 | 45篇 |
2000年 | 46篇 |
1999年 | 30篇 |
1998年 | 11篇 |
1997年 | 12篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1993年 | 3篇 |
1992年 | 19篇 |
1991年 | 13篇 |
1990年 | 11篇 |
1989年 | 19篇 |
1988年 | 17篇 |
1987年 | 14篇 |
1986年 | 6篇 |
1985年 | 12篇 |
1984年 | 14篇 |
1983年 | 7篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1979年 | 13篇 |
1978年 | 6篇 |
1976年 | 11篇 |
1975年 | 5篇 |
1974年 | 10篇 |
1973年 | 3篇 |
1972年 | 7篇 |
1968年 | 5篇 |
排序方式: 共有1546条查询结果,搜索用时 46 毫秒
31.
32.
Adil Mehraj Khan Rajinder Raina Nitin Dubey Pawan Kumar Verma 《Drug and chemical toxicology》2018,41(2):123-127
The study evaluated the effect of commercial preparation of deltamethrin, Butox®, and fluoride (F?) co-exposure on the brain antioxidant status and cholinesterase activity in rats. Group A was untreated. Group B was gavaged Butox®, providing deltamethrin at the dose rate of 1.28?mg per kg body weight per day. Group C was administered F?, as NaF, in drinking water providing 20?ppm F?. Group D received both deltamethrin and F? at the same dosages as groups B and C, respectively. Although, glutathione S-transferase activity was induced only in Butox® alone treated group, the activities of superoxide dismutase and catalase were inhibited in all treatment groups when compared to the control group. Elevated lipid peroxidation was observed in the groups exposed to F?. The activity of erythrocyte acetylcholinesterase (AChE) was inhibited in Butox® treated groups, whereas brain AChE activity was inhibited in all treatment groups. In conclusion, both deltamethrin (given as Butox®) and F? inhibit AChE activity and produce oxidative stress in brain with F? producing more oxidative damage. However, compared to the individual exposures, the co-exposure of these chemicals does not produce any exacerbated alteration in these biochemical parameters. 相似文献
33.
34.
Immunization is an established, cost-effective, preventive intervention to improve child survival. To provide protection against vaccine preventable diseases, all countries in the world have an immunization program that offers selected vaccines to the eligible beneficiaries. In India, Expanded Program of Immunization was started in 1978, and then Universal Immunization Program was launched in 1985 with six antigens. This article describes the experience with institutionalization of four state-specific vaccines by Delhi in its immunization schedule to enlarge the ambit of immunization services. It attempts to highlight the state’s perspective in terms of the implementation policy, operational strategy adopted and evolution of immunization program in the state over 16 years. 相似文献
35.
36.
Summary The extent of reduced glutathione, activity of glutathione peroxidase, amount of membrane lipid peroxidation products, and the extent of hemoglobin release from host erythrocytes during in vitroPlasmodium falciparum growth was studied. Highly synchronized parasite cultures were studied to examine the alterations caused by different growth stages of the parasite. There was a moderate increase in the reduced glutathione content as the parasite matured, which was significant only in schizontrich erythrocyte lysates (p<0.05) whereas the activity of glutathione peroxidase was significantly low in all the parasitized red blood cells (ring-infected RBC,p<0.005; trophozoite- and schizont-infected RBC,p<0.001). The lipid peroxidation product, malonyldialdehyde, of the host red cells increased gradually to more than fourfold in schizont-rich cells as compared with normal erythrocytes (p<0.001). The hemoglobin release from cultured cells was significantly higher in all parasitized red cell cultures as well as in uninfected cells kept in in vitro, as compared with normal erythrocytes. The consequence of such changes induced by the malarial parasites in the host red cells in the pathogenesis of erythrocyte destruction and anemia ofP. falciparum malaria is discussed. 相似文献
37.
Western blot analysis of antibody to varicella-zoster virus 总被引:3,自引:0,他引:3
L Dubey S P Steinberg P LaRussa P Oh A A Gershon 《The Journal of infectious diseases》1988,157(5):882-888
We used western blot (WB) to compare the IgG response to varicella-zoster virus (VZV) after chickenpox (CP), zoster, and administration of a live attenuated varicella vaccine (LAVV). After CP, 13 of 14 normal children had antibody to glycoprotein (gp) I (99 and 92 kilodaltons [kDa]), 11 had antibody to gpII (133 kDa), and 10 had antibody to gpIII (119 kDa). Bands at 150 and 35 kDa were also seen in 13 and 11 sera, respectively. Bands to gpI, gpII, and p35 were more intense after zoster than CP. After one dose of LAVV, eight of eight normal children had gpI antibody. In leukemic children, gpI antibody appeared in 18 (56%) after one dose and in 25 (89%) after two doses. Upon household exposure, leukemic vaccinees who developed CP were less likely than those protected to have prior gpIII and p35 antibodies. As seen after zoster, WBs after breakthrough CP showed intense responses to VZV antigens. Thus, WB helps distinguish secondary from primary antibody responses to VZV. 相似文献
38.
An unusual presentation of sinus of Valsalva aneurysm causing right ventricular outflow tract obstruction and presenting as acute coronary syndrome is reported. A 38-year-old lady presented with ischemic chest pain, probably due to embolization from an unruptured sinus of Valsalva aneurysm. 相似文献
39.
Vascular smooth muscle and glomerular mesangial cells in culture express a biochemical pathway that methylates 2-hydroxyestradiol (17beta-estradiol metabolite) to produce 2-methoxyestradiol, a cell growth inhibitor that may mediate the cardiorenal protective effects of 17beta-estradiol. Whether this pathway exists in intact organ systems is currently unclear. Accordingly, the purpose of the present investigation was to characterize the methylation of 2-hydroxestradiol in intact organs from both male and female rats. No significant differences were detected in the ability of male and female tissues to methylate 2-hydroxyestradiol. In isolated hearts, kidneys, and mesenteries perfused with Tyrode's solution, Km values for 2-hydroxyestradiol methylation were 0.175+/-0.021, 0.387+/-0.054, and 0.495+/-0.089 micromol/L, respectively, and Vmax values were 21.0+/-1.58, 24.9+/-1.49, and 1.01+/-0.148 pmol 2-methoxyestradiol x min(-1) x ml(-1) per gram, respectively. The catalytic efficiency (Vmax/Km) was greatest in the heart compared with the kidney and mesentery (132+/-14.3, 78.4+/-15.1, and 2.30+/-0.263 pmol 2-methoxyestradiol x min(-1) x mL(-1) x micromol/L(-1) per gram, respectively). In the kidney, the catechol-O-methyltransferase inhibitor quercetin and norepinephrine (10 micromol/L) reduced methylation of 2-hydroxyestradiol by approximately 90% and 41%, respectively. Importantly, methylation in the kidney was inhibited by an average of 16.6+/-1.80% by endogenous norepinephrine released by renal artery nerve stimulation. Our results indicate that a robust 2-hydroxyestradiol methylation pathway exists in the kidney and heart, but not in the mesentery, and that this pathway is mediated by catechol-O-methyltransferase. Our findings also suggest that catecholamines may interfere with 2-hydroxyestradiol methylation and thereby attenuate the cardiorenal protective effects of 17beta-estradiol. 相似文献
40.