全文获取类型
收费全文 | 1270篇 |
免费 | 45篇 |
国内免费 | 3篇 |
专业分类
儿科学 | 73篇 |
妇产科学 | 14篇 |
基础医学 | 85篇 |
口腔科学 | 26篇 |
临床医学 | 117篇 |
内科学 | 348篇 |
皮肤病学 | 21篇 |
神经病学 | 30篇 |
特种医学 | 252篇 |
外科学 | 51篇 |
综合类 | 44篇 |
预防医学 | 98篇 |
眼科学 | 22篇 |
药学 | 36篇 |
中国医学 | 1篇 |
肿瘤学 | 100篇 |
出版年
2023年 | 3篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 12篇 |
2017年 | 11篇 |
2016年 | 9篇 |
2015年 | 16篇 |
2014年 | 19篇 |
2013年 | 22篇 |
2012年 | 32篇 |
2011年 | 25篇 |
2010年 | 46篇 |
2009年 | 56篇 |
2008年 | 63篇 |
2007年 | 64篇 |
2006年 | 54篇 |
2005年 | 41篇 |
2004年 | 28篇 |
2003年 | 32篇 |
2002年 | 22篇 |
2001年 | 26篇 |
2000年 | 19篇 |
1999年 | 25篇 |
1998年 | 49篇 |
1997年 | 66篇 |
1996年 | 49篇 |
1995年 | 41篇 |
1994年 | 51篇 |
1993年 | 51篇 |
1992年 | 18篇 |
1991年 | 16篇 |
1990年 | 18篇 |
1989年 | 39篇 |
1988年 | 42篇 |
1987年 | 33篇 |
1986年 | 33篇 |
1985年 | 30篇 |
1984年 | 13篇 |
1983年 | 21篇 |
1982年 | 17篇 |
1981年 | 18篇 |
1980年 | 21篇 |
1979年 | 3篇 |
1978年 | 9篇 |
1977年 | 12篇 |
1976年 | 9篇 |
1975年 | 18篇 |
1969年 | 1篇 |
1948年 | 1篇 |
排序方式: 共有1318条查询结果,搜索用时 31 毫秒
1.
2.
Myrto Barrdahl Federico Canzian Sara Lindström Irene Shui Amanda Black Robert N. Hoover Regina G. Ziegler Julie E. Buring Stephen J. Chanock W. Ryan Diver Susan M. Gapstur Mia M. Gaudet Graham G. Giles Christopher Haiman Brian E. Henderson Susan Hankinson David J. Hunter Amit D. Joshi Peter Kraft I‐Min Lee Loic Le Marchand Roger L. Milne Melissa C. Southey Walter Willett Marc Gunter Salvatore Panico Malin Sund Elisabete Weiderpass María‐José Sánchez Kim Overvad Laure Dossus Petra H Peeters Kay‐Tee Khaw Dimitrios Trichopoulos Rudolf Kaaks Daniele Campa 《International journal of cancer. Journal international du cancer》2015,137(12):2837-2845
The survival of breast cancer patients is largely influenced by tumor characteristics, such as TNM stage, tumor grade and hormone receptor status. However, there is growing evidence that inherited genetic variation might affect the disease prognosis and response to treatment. Several lines of evidence suggest that alleles influencing breast cancer risk might also be associated with breast cancer survival. We examined the associations between 35 breast cancer susceptibility loci and the disease over‐all survival (OS) in 10,255 breast cancer patients from the National Cancer Institute Breast and Prostate Cancer Cohort Consortium (BPC3) of which 1,379 died, including 754 of breast cancer. We also conducted a meta‐analysis of almost 35,000 patients and 5,000 deaths, combining results from BPC3 and the Breast Cancer Association Consortium (BCAC) and performed in silico analyses of SNPs with significant associations. In BPC3, the C allele of LSP1‐rs3817198 was significantly associated with improved OS (HRper‐allele=0.70; 95% CI: 0.58–0.85; ptrend = 2.84 × 10?4; HRheterozygotes = 0.71; 95% CI: 0.55–0.92; HRhomozygotes = 0.48; 95% CI: 0.31–0.76; p2DF = 1.45 × 10?3). In silico, the C allele of LSP1‐rs3817198 was predicted to increase expression of the tumor suppressor cyclin‐dependent kinase inhibitor 1C (CDKN1C). In the meta‐analysis, TNRC9‐rs3803662 was significantly associated with increased death hazard (HRMETA =1.09; 95% CI: 1.04–1.15; ptrend = 6.6 × 10?4; HRheterozygotes = 0.96 95% CI: 0.90–1.03; HRhomozygotes = 1.21; 95% CI: 1.09–1.35; p2DF=1.25 × 10?4). In conclusion, we show that there is little overlap between the breast cancer risk single nucleotide polymorphisms (SNPs) identified so far and the SNPs associated with breast cancer prognosis, with the possible exceptions of LSP1‐rs3817198 and TNRC9‐rs3803662. 相似文献
3.
4.
L. Djoussé J.A. Driver J.M. Gaziano J.E. Buring I.M. Lee 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2013,23(1):17-22
Background and aimsWhile clinical trials have reported beneficial effects of diet, exercise, and weight loss on incident diabetes in subjects with obesity or impaired glucose tolerance, little is known about the incremental benefit of not smoking and moderate drinking on diabetes risk. We sought to examine the association between modifiable lifestyle factors and residual lifetime risk of diabetes.Methods and ResultsProspective cohorts involving 20,915 men (1982–2008) and 36,594 women (1992–2008). Modifiable lifestyle factors and adiposity were ascertained at baseline in each cohort and incident diabetes was ascertained during follow up. The mean age at baseline was 53.5 y in men and 54.6 y in women. During an average follow up of 22.6 y in men and 13.0 y in women, 2096 men and 2390 women developed diabetes. At age 45 y, the residual lifetime risk of diabetes (95% CI) for men with 0, 1, 2, 3, and 4 + healthy lifestyle factors was 30.5 (27.3–33.7); 21.5 (19.9–23.0); 15.1 (13.9–16.3); 10.3 (9.1–11.5); and 7.3 (5.7–8.9) percent; respectively. Corresponding values for women were 31.4 (28.3–34.5); 24.1 (21.8–26.5); 14.2 (12.7–15.7); 11.6 (9.7–13.5); and 6.4 (4.2–8.6) percent, respectively.ConclusionsThese data show an inverse and graded relation between desirable lifestyle factors and residual lifetime risk of diabetes in men and women. Not smoking and moderate drinking may have additional benefits when added to exercise, weight control, and diet. 相似文献
5.
6.
Adverse effects of the transfusion of homologous blood on tumor recurrence and resistance to bacterial infection have been reported previously, but the findings are inconclusive. A retrospective review of patients undergoing orthopedic surgery was conducted, and the rate of the postoperative infectious complications was compared among those receiving homologous blood, autologous blood, both types, or no transfusion support. An overall postoperative infection rate of 6.1 percent was observed: 6.9 percent among persons receiving homologous blood, 5.0 percent among those receiving autologous blood, 11.9 percent among those receiving both homologous and autologous blood, and 4.9 percent among those not receiving transfusions (p = 0.37). Among patients receiving homologous blood, a subset of 15 patients received homologous whole blood and had an infection rate of 20 percent. Significant predictors of postoperative infection included increasing age, spinal surgery, high admission hematocrit, and greater time in surgery. Of factors relating to transfusion, only the use of homologous whole blood was a significant predictor of postoperative infection, which suggests a detrimental effect of homologous plasma. It can be concluded that, in this group of patients undergoing relatively nontraumatic surgery, several variables that are not related to transfusion, as well as the use of homologous whole blood, were significant predictors of postoperative infection. 相似文献
7.
Combined oral lysine acetylsalicylate and metoclopramide in the acute treatment of migraine: a multicentre double-blind placebo-controlled study 总被引:3,自引:0,他引:3
H Chabriat JE Joire J Danchot P Grippon MG Bousser 《Cephalalgia : an international journal of headache》1994,14(4):297-300
This multicentre, double-blind, randomized, placebo-controlled, parallel study was designed to evaluate the efficacy of combined oral lysine acetylsalicylate and metoclopramide (LAS-MCP) in the acute treatment of migraine attacks. A total of 266 patients, 18–65 years old, with two to six attacks of migraine with or without aura (IHS criteria) per month were included. The patients had to treat two migraine attacks with LAS-MCP (1620 mg lysine acetylsalicylate-the equivalent of 900 mg aspirin- combined with 10 mg metoclopramide) or placebo. The main outcome measure was headache relief (reduction in headache severity from grade 3 or 2-severe or moderate-to grade 1 or 0-mild or none) 2 h after treatment. LAS-MCP was superior to placebo for headache relief (56% vs 28%) and for the following secondary outcome measures: complete headache relief (18% vs 7%; p < 0.001), nausea (28% vs 44%; p < 0.001), vomiting (3% vs 11%; p = 0.001), use of rescue medication (47% vs 68%; p < 0.001), global efficacy judged as good or excellent (32% vs 14%; p < 0.001). The tolerability was considered as good in 94% of treated attacks in both groups. Combined oral lysine acetylsalicylate and metoclopramide is an effective and well-tolerated acute treatment of migraine attacks. 相似文献
8.
The effect of sterilization on transforming growth factor beta isolated from demineralized human bone 总被引:1,自引:0,他引:1
Growth factors have been identified as the primary cause of osteoinduction in bone healing. Transforming growth factor beta (TGF- beta) has been shown to promote bone formation and is present in bone in high quantities. The aims of the present study were to isolate TGF- beta from human bone, demonstrate its biologic activity, and analyze the effects of conventional sterilization techniques on activity. Bone, obtained from femoral heads of five patients (mean age, 70 years) was ground, demineralized, and freeze-dried, and samples from each patient were divided into three groups: no treatment, sterilization with 1.60 to 1.94 Mrad of 60Co irradiation, and sterilization with ethylene oxide (ETO). Carrier-free recombinant TGF-beta control was also treated and was totally inactivated by ETO but not by irradiation (p < 0.01). TGF- beta activity in demineralized bone was not significantly diminished (p > 0.1) by either sterilization procedure, and substantial amounts of active TGF-beta were recovered in all bone samples: 1.04 +/− 0.77 ng per mg of protein in irradiated samples, 0.67 +/− 0.26 ng per mg in ETO- treated samples, and 1.04 +/− 0.33 in untreated samples, respectively (mean +/− SD). Although a recent report demonstrated that the osteoinductive activity of bone morphogenetic protein in bone powder is diminished considerably by ETO and by 2.5 Mrad of irradiation sterilization of bone powder, these data demonstrate that TGF-beta activity, with its osteoinductive properties, was not destroyed in more coarsely ground, demineralized bone by ETO or by lower doses of irradiation. These findings support the use of human bone allografts in clinical instances involving impaired bone formation. 相似文献
9.
目的:观察碱性成纤维细胞生长因子对大鼠脑出血后出血灶周围脑组织和出血侧海马bax、bcl-2基因表达的影响,探讨神经营养因子对神经细胞调亡的调控。方法:实验于2006-01/10在广西医科大学医学科学实验中心完成。①取成年清洁级Wistar大鼠72只,雌雄各半,体质量250g左右。②采用脑内囊注射胶原酶建立大鼠脑出血模型,动物于苏醒后按Bederson法进行神经病学评分,评分>3分后入选本实验,入选72只大鼠随机抽签法分为3组,每组24只。碱性成纤维细胞生长因子组按8μg/kg剂量肌肉注射,1次/d;生理盐水组肌肉注射等剂量的生理盐水,1次/d;模型组不作任何干预。③每组分别于干预后1,3,7d随机抽取8只大鼠,麻醉状态下取出血灶周围脑组织和出血侧海马,采用半定量反转录-聚合酶链反应检测调亡调控基因bax mRNA,bcl-2mRNA的表达。结果:在建立脑出血模型中共5只大鼠死亡,随后对死亡动物进行解剖,发现脑内血肿量过大,致脑疝形成而导致死亡,后随机补充动物。72只大鼠进入结果分析。①血肿周围脑组织bax mRNA表达:干预后3d,7d,碱性成纤维细胞生长因子组血肿周围脑组织bax mRNA表达比生理盐水组明显减少(3d:0.54±0.19,0.76±0.23,P<0.05;7d:0.45±0.19,0.71±0.16,P<0.01)。②血肿周围脑组织bcl-2mRNA表达:干预后3d,7d,碱性成纤维细胞生长因子组的血肿周围脑组织bcl-2mRNA表达比生理盐水组明显增高(3d:0.68±0.25,0.39±0.19,P<0.05;7d:0.80±0.21,0.48±0.18,P<0.01)。③出血侧海马bax mRNA表达:干预后3d和7d,碱性成纤维细胞生长因子组的出血侧海马bax mRNA表达比生理盐水组均明显减少(3d:0.54±0.18,0.70±0.11;7d:0.43±0.24,0.69±0.18,P均<0.05)。④出血侧海马bcl-2mRNA表达:干预后3d和7d,碱性成纤维细胞生长因子组的出血侧海马bcl-2mRNA表达比生理盐水组均明显增多(3d:0.66±0.11,0.50±0.15;7d:0.72±0.12,0.52±0.22,P均<0.05)。结论:碱性成纤维细胞生长因子能调节凋亡相关基因,提高大鼠脑出血后大脑脑组织和海马bcl-2mRNA的表达,降低bax mRNA的表达。 相似文献
10.
P M Ridker J E Manson J E Buring S Z Goldhaber C H Hennekens 《American heart journal》1991,122(6):1588-1592
Low-dose aspirin has been postulated to decrease risks of cardiovascular disease by affecting atherosclerotic progression as well as acute thrombosis. In the Physicians' Health Study, a randomized double-blind placebo-controlled trial of alternate day aspirin (325 mg), 22,071 apparently healthy male physicians were treated and followed over a period of 5 years for the occurrence of myocardial infarction and of new angina pectoris. In an analysis of the cumulative incidence and cumulative relative risks of these end points, it was found that the full protective effect of aspirin in reducing the risk of myocardial infarction is apparent soon after initiation of therapy and does not change over time. In contrast, long-term aspirin therapy has no apparent role in decreasing the risk of developing future angina pectoris. Taken together, these clinical observations support the hypothesis that the primary effect of prophylactic low-dose aspirin therapy is to inhibit acute thrombosis, but do not support the hypothesis that long-term platelet inhibition for a duration of up to 5 years slows the initiation and progression of atherosclerosis. 相似文献