全文获取类型
收费全文 | 2637219篇 |
免费 | 199197篇 |
国内免费 | 4988篇 |
专业分类
耳鼻咽喉 | 37790篇 |
儿科学 | 83925篇 |
妇产科学 | 76070篇 |
基础医学 | 371014篇 |
口腔科学 | 79553篇 |
临床医学 | 229089篇 |
内科学 | 512032篇 |
皮肤病学 | 58373篇 |
神经病学 | 212631篇 |
特种医学 | 105317篇 |
外国民族医学 | 879篇 |
外科学 | 403725篇 |
综合类 | 64340篇 |
现状与发展 | 9篇 |
一般理论 | 918篇 |
预防医学 | 195805篇 |
眼科学 | 62109篇 |
药学 | 199358篇 |
7篇 | |
中国医学 | 5390篇 |
肿瘤学 | 143070篇 |
出版年
2018年 | 24048篇 |
2015年 | 24238篇 |
2014年 | 33661篇 |
2013年 | 51637篇 |
2012年 | 68634篇 |
2011年 | 72544篇 |
2010年 | 43085篇 |
2009年 | 41250篇 |
2008年 | 69670篇 |
2007年 | 74527篇 |
2006年 | 75502篇 |
2005年 | 73431篇 |
2004年 | 71907篇 |
2003年 | 69340篇 |
2002年 | 68141篇 |
2001年 | 122297篇 |
2000年 | 126048篇 |
1999年 | 107352篇 |
1998年 | 29260篇 |
1997年 | 26613篇 |
1996年 | 26102篇 |
1995年 | 25090篇 |
1994年 | 23587篇 |
1993年 | 22131篇 |
1992年 | 86557篇 |
1991年 | 83930篇 |
1990年 | 82173篇 |
1989年 | 80077篇 |
1988年 | 74557篇 |
1987年 | 73398篇 |
1986年 | 70077篇 |
1985年 | 67224篇 |
1984年 | 50357篇 |
1983年 | 43236篇 |
1982年 | 25665篇 |
1981年 | 23212篇 |
1980年 | 21748篇 |
1979年 | 48270篇 |
1978年 | 34033篇 |
1977年 | 29064篇 |
1976年 | 26820篇 |
1975年 | 29305篇 |
1974年 | 35464篇 |
1973年 | 34209篇 |
1972年 | 32026篇 |
1971年 | 30116篇 |
1970年 | 28130篇 |
1969年 | 26723篇 |
1968年 | 24848篇 |
1967年 | 22376篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
Zinc sulfate addition to glass-ionomer-based cements: influence on physical and antibacterial properties, zinc and fluoride release. 总被引:5,自引:0,他引:5
Prudencio W R Osinaga Rosa Helena M Grande Rafael Y Ballester Maria Regina L Simionato Célia Regina M Delgado Rodrigues Antonio Muench 《Dental materials》2003,19(3):212-217
OBJECTIVES: The aim of this study is to evaluate the effect of ZnSO(4) addition to a conventional glass ionomer and a resin-modified glass ionomer on solubility, flexural strength, zinc and fluoride (F) release, and Streptococcus mutans growth inhibition. METHODS: 5 or 10% ZnSO(4) was added to Vitremer and Ketac-Fil powders. Solubility test was performed based on ISO 7489. Flexural strength was determined by 3-point bending test based on ISO 4049. Zn release/uptake was determined by atomic emission spectrometry; F release/uptake was measured using a F-specific electrode. Both release measurements were performed for 15 d before and 15 d after recharging. Antibacterial test was conducted according to agar plate methods against S. mutans, by measuring the inhibition halos in 1-h and 15-d specimens. Data were analyzed by ANOVA. RESULTS: Solubility increased with higher ZnSO(4) content, but remained below the ISO 7489 limit. Flexural strength was not affected by ZnSO(4) addition, and Vitremer performed better than Ketac-Fil. The control materials released no zinc. Vitremer with 10% ZnSO(4) released the highest amount of zinc. Fluoride release was similar for Ketac-Fil and Vitremer. In both cases, the highest amounts were released in the first 24 h. The growth inhibition halo of S. mutans was similar for both materials with highest content of ZnSO(4) and occurred only with 1-h specimens. SIGNIFICANCE: Zinc addition decreased microorganisms growth and improved fluoride release, without significantly affecting the materials' flexural strength and solubility. 相似文献
53.
54.
Dr. med. Dr. jur. R. Erlinger 《Der Onkologe》2003,9(8):865-868
Ohne Zusammenfassung 相似文献
55.
La Creis R Kidd K Woodson P R Taylor D Albanes J Virtamo J A Tangrea 《European journal of cancer prevention》2003,12(4):317-320
Glutathione-S-transferase (GST) genes encode a family of detoxification enzymes that offer protection against endogenous and exogenous sources of reactive oxygen species (ROS). Germline variations in GST genes may alter the catalytic efficiency of GST isoenzymes leading to a potential increase in susceptibility to the genotoxic effects of ROS and electrophilic substances. A nested case-control study design was used to examine the association between the polymorphic GST genes and prostate cancer risk among Finnish male smokers of the ATBC Cancer Prevention Study. A case-case analysis was used to determine the association between these genetic polymorphisms and prostate cancer progression. Germline DNA was obtained from 206 prostate cancer cases and 194 controls frequency matched on age, intervention group and study clinic. Cases and controls were genotyped for three GST genes using MALDI-TOF mass spectrometry or multiplex polymerase chain reaction (PCR). Relative to the wild-type genotype, we observed a 36% reduction in prostate cancer risk associated with the GST-M1-null genotype (odds ratio (OR) 0.64, 95% confidence interval (CI) 0.43, 0.95). Unlike GST-M1, GST-T1-null (OR 0.74, 95% CI 0.42, 1.33) and GST-P1*B (OR 1.10, 95% CI 0.72, 1.69) were not strongly associated with prostate cancer risk. We did not observe any significant associations between the selected polymorphic GST genes and tumour grade or stage. In conclusion, we did not observe a direct association between polymorphic GST-T1 or GST-P1 and prostate cancer risk. Our observation of a relatively strong inverse association between the GST-M1-null genotype and prostate cancer risk needs to be confirmed in larger association studies. 相似文献
56.
The precise molecular cause of insulin resistance has not yet been elucidated. Resistance to the normal action of insulin contributes to the pathogenesis of a number of common human disorders, including type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetes mellitus, hypertension, and the Metabolic Syndrome X, thus constituting a major public health problem. A disease program aimed at combating this disorder should focus on the identification of targets for therapeutic intervention which may overcome insulin resistance and hence the associated metabolic consequences characteristic of the Metabolic Syndrome. Although the primary defect in the pathogenesis of type 2 diabetes is unknown, genetic and environmental factors are likely to contribute to the manifestation of this progressive metabolic disorder, which is usually not clinically apparent until mid-life. Defects at the level of glucose uptake/phosphorylation characterize insulin resistance in skeletal muscle of type 2 diabetic patients. Identification of putative components of the insulin receptor-signaling pathway may offer insights into mechanisms involved in insulin resistance. Enhanced flux of free fatty acids due to impaired lipid metabolism may contribute to impaired insulin secretion and peripheral insulin resistance. Genes regulating lipolysis are prime candidates for susceptibility towards the metabolic syndrome. Here we describe pathways constituting complex interactions that control glucose homeostasis. We will be considering (1) regulation of glucose uptake by the insulin receptor signaling pathway, and (2) control of adipogenesis and insulin sensitivity by the sterol response element binding protein (SREBP) pathway. 相似文献
57.
58.
59.
60.
P E Santos E Piontelli Y R Shea M L Galluzzo S M Holland M E Zelazko S D Rosenzweig 《Medical mycology》2006,44(8):749-753
Infections due to Penicillium species other than P.marneffei are rare. We identified a boy with X-linked chronic granulomatous disease (X-CGD) with a pulmonary nodule and adjacent rib osteomyelitis caused by Penicillium piceum. The only sign of infection was an elevated sedimentation rate. P. piceum was isolated by fine needle aspirate and from excised infected tissues. Surgical removal and one year of voriconazole treatment were very well tolerated and led to complete recovery. Microbiological, microscopic and molecular studies support the fungal diagnosis. P. piceum should be considered as a relevant pathogen in immunocompromised patients. 相似文献