全文获取类型
收费全文 | 4521篇 |
免费 | 310篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 207篇 |
妇产科学 | 82篇 |
基础医学 | 716篇 |
口腔科学 | 170篇 |
临床医学 | 533篇 |
内科学 | 1087篇 |
皮肤病学 | 144篇 |
神经病学 | 239篇 |
特种医学 | 335篇 |
外科学 | 401篇 |
综合类 | 111篇 |
一般理论 | 2篇 |
预防医学 | 365篇 |
眼科学 | 59篇 |
药学 | 234篇 |
中国医学 | 3篇 |
肿瘤学 | 150篇 |
出版年
2021年 | 63篇 |
2018年 | 58篇 |
2017年 | 46篇 |
2016年 | 45篇 |
2015年 | 75篇 |
2014年 | 73篇 |
2013年 | 156篇 |
2012年 | 135篇 |
2011年 | 116篇 |
2010年 | 96篇 |
2009年 | 85篇 |
2008年 | 111篇 |
2007年 | 144篇 |
2006年 | 150篇 |
2005年 | 148篇 |
2004年 | 114篇 |
2003年 | 113篇 |
2002年 | 103篇 |
2001年 | 110篇 |
2000年 | 113篇 |
1999年 | 101篇 |
1998年 | 120篇 |
1997年 | 113篇 |
1996年 | 127篇 |
1995年 | 87篇 |
1994年 | 100篇 |
1993年 | 96篇 |
1992年 | 84篇 |
1991年 | 83篇 |
1990年 | 92篇 |
1989年 | 113篇 |
1988年 | 98篇 |
1987年 | 101篇 |
1986年 | 100篇 |
1985年 | 79篇 |
1984年 | 84篇 |
1983年 | 49篇 |
1982年 | 45篇 |
1981年 | 54篇 |
1980年 | 62篇 |
1979年 | 48篇 |
1978年 | 44篇 |
1977年 | 47篇 |
1976年 | 56篇 |
1975年 | 49篇 |
1970年 | 44篇 |
1965年 | 52篇 |
1964年 | 50篇 |
1963年 | 51篇 |
1960年 | 66篇 |
排序方式: 共有4865条查询结果,搜索用时 0 毫秒
91.
92.
93.
94.
95.
96.
1. Three cases of hereditary hemolytic disease secondary to G-6-PD deficiency are described. Two of the cases were first cousins of Scotch-Irish-English descent and the mode of inheritance was believed to be sex-linked.The third case was of Turkish origin; no family studies were availale.2. The mothers, who were heterozygous for G-6-PD deficiency, showed onlyminimal expression of the defect, which was manifested by a slightly decreasedred cell survival in both mothers and an abnormal methemoglobin reductiontest in one of them.3. All three cases showed a more pronounced fall in erythrocyte ATP afterincubation with phenylhydrazine than that observed in primaquine-sensitiveNegroes whose red cells were less deficient in G-6-PD.4. It is suggested that the inability of the G-6-PD-deficient erythrocyte tomaintain adequate levels of ATP may be an important factor in the pathogenesis of the hemolytic process. Submitted on August 26, 1963 Accepted on October 24, 1963 相似文献
97.
Interventions in saphenous vein grafts present some of the most challenging problems in preventing acute complications and limiting restenosis. Available options include repeat bypass surgery, balloon angioplasty, directional atherectomy, transluminal extraction atherectomy, rotational atherectomy, laser angioplasty, and stenting. Stenting appears to provide the best acute and long-term results. Debulking with directional atherectomy prior to stenting may be helpful but its role is unproven. With any device, it is essential to attain the lowest possible residual stenosis with the least amount of manipulation. Complications with vein graft interventions are most commonly related to distal embolization, which occurs most frequently in older vein grafts with diffuse disease, large plaque volume or thrombus, or those with total occlusion. Use of thrombolytics, glycoprotein Ilb/IIIa receptor inhibitors, and thrombectomy devices may be helpful when thrombus is present. Calcium channel blockers may be beneficial when embolization of plaque debris results in slow flow or no-flow during interventions. 相似文献
98.
恰如其分的外周髓鞘形成取决于雪旺细胞增殖与分化进程间的平衡。丝氨酸/苏氨酸激酶(mTOR)整合多种环境因素,是细胞生长、代谢、发挥作用的中枢调节者。本文报道了一种mTOR的负性调节剂——结节性硬化复合体(TSC1),通过控制细胞增殖和髓鞘稳态,建立了雪旺细胞谱系进展和髓鞘形成的阶段依赖性程序。小鼠雪旺细胞祖细胞中TSC1的解离导致mTOR信号通路激活,继而导致雪旺细胞过量增殖,分化受阻,髓鞘形成减少。转录组分析显示,TSC1突变体中的mTOR活化使得polo样激酶(PLK)依赖性通路和细胞周期调节剂上调。弱化mTOR或者对PLK进行药理抑制部分挽救了因TSC1缺失导致的外周神经发育过程中的髓鞘形成减少。相较之下,成年小鼠成熟雪旺细胞中TSC1缺失可导致髓鞘的过度增殖和过度生长。本文的发现提示了TSC1-mTOR-PLK信号轴在控制雪旺细胞的发育过程中,从增殖到分化和髓鞘内稳态中起到的阶段特异性功能。 相似文献
99.
Schellenberg D Menendez C Aponte J Guinovart C Mshinda H Tanner M Alonso P 《Tropical medicine & international health : TM & IH》2004,9(1):68-76
Between 1995 and 2000 there were marked changes in the epidemiology of malaria in Ifakara, southern Tanzania. We documented these changes using parasitological and clinical data from a series of community- and hospital-based studies involving children up to the age of 5 years. There was a right shift and lowering in the age-specific parasite prevalence in the community-based cohort studies. The incidence of clinical malaria in placebo-receiving infants in additional study cohorts dropped from 0.8 in 1995 to 0.43 episodes per infant per year in 2000, an incidence rate ratio of 0.53 (95% confidence interval: 0.404, 0.70, P<0.0001). At the same time, there was an increase in the total number of malaria admissions and a marked right shift in the age pattern of these admissions (median age in 1995 1.55 years vs. 2.33 in 2000, P<0.0001). However, the burden of malaria deaths remained in infants. We discuss how these dramatic changes in the epidemiology of malaria may have arisen from the use of currently available malaria control tools. Caution is required in the interpretation of hospital-based data as it is likely to underestimate the impact of anaemia on mortality in the community, where most paediatric deaths occur. Even in low/moderate malaria transmission settings, where older children suffer most malaria episodes, targeting effective malaria control at infants may produce important reductions in infant mortality caused by malaria. 相似文献
100.
Dr. K. Mealy M.D. F.R.C.S.I. E. O'Broin F.R.C.S.I. J. Donohue M.B. A. Tanner M.D. F.R.C.S.I. F. B. V. Keane M.D. F.R.C.S.I. 《Diseases of the colon and rectum》1996,39(11):1227-1231
Purpose: The trend toward avoidance of a colostomy at both elective and emergency large-bowel surgery is partly driven by the perceived morbidity and low closure rates of temporary stomas. The aim of this study was to examine whether significant colostomy-related morbidity remains persistently high. METHODS: To examine this, we reviewed 120 patients with a potentially reversible colostomy performed during either elective or emergency large-bowel surgery during a seven-year period. RESULTS Forty-seven patients underwent elective and 73 patients underwent emergency colonic or colorectal resection. Fifty-eight patients had colorectal carcinoma (48.3 percent), diverticular disease accounted for 39 patients (32.5 percent), and a miscellaneous group of 23 patients (19.2 percent) made-up the remainder. Seven patients died, all in the emergency group (9.6 percent). Colostomy-related morbidity, which included stenosis, retraction, prolapse, and hernia formation, occurred in 19.2 percent of patients, with no difference between the elective (14.9 percent) and emergency (21.9 percent) groups or underlying pathologic condition. Colostomy closure was performed initially in 71 patients (59.2 percent). Highest closure rates occurred in the diverticular group (84.6 percent), followed by the colorectal carcinoma group (48.3 percent), and then the miscellaneous group (43.5 percent). One patient died undergoing colostomy closure, and complications occurred in 25 patients (35.2 percent), requiring fashioning of a second colostomy in eight patients, two of whom were closed. Final colostomy closure rate was 54.2 percent. CONCLUSIONS: This study confirms the contention that both formation and closure of defunctioning colostomies are associated with significant complications; furthermore, approximately one-half of patients will not have their colostomy closed. 相似文献