309 research outputs found
The Method of Auxiliary Sources as an Efficient Numerical Technique for Large 3D Semi Open Structures
The method of auxiliary sources (MAS) has been demonstrated as suitable for solution of diffraction and inverse problems in complex 2D large objects. Based on MAS numerical study of 3D RCS, EMC/EMI and SAR problems, related to the EM field resonance enhancement inside vehicles and the interaction of the cellular telephone radiation with the user\u27\u27s head are given in other work. The objective of this paper is to present details of MAS application to the wide 3D electrodynamic problems. The area of its efficient application, some features and advantages to achieving efficient solutions, are discussed. The extension of the MAS for semi-open structures with partitions is also presented
Electromagnetic Analysis for Vehicle Antenna Development Using Method of Auxiliary Sources
In paper [l] the electromagnetic analysis of large semi-open structures like vehicles was presented formulated as scattering problem, illuminated by a wide range of incident EM fields. The effect of resonances within the semi-open structure on the RCS, near fields and pattem of reradiated fields had been shown. In this paper the interaction of the entire semi-open structure on the performance of an antenna is considered together with the investigation of near field distributions inside the cavity. The Method of Auxiliary Sources (MAS) [2] is utilized. For a simple geometry the results are compared to measurements
MAS-MoM Hybrid Method with Wire\u27s Image using in Excitation Problems
An important class of problems is the interaction of an antenna with the cavity of a semi-open metallic structure. In a working environment, an antenna may change its performance due to interactions with its surroundings. This is especially true in automotive applications. Therefore, it is important to consider the interaction of an antenna with possible resonating parts, and to solve these complex electrodynamics problems together. The development of methods for modeling and studying electromagnetic compatibility (EMC) problems has practical value. The method of auxiliary sources (MAS) with the method of moments (MoM) is applied to solve the excitation problem where a wire, with voltage source excitation, is connected to an open metallic surface. For verification of the proposed algorithm, an experimental structure was built and measured. Computer modeling results and the experimental results are in good agreement. Some aspects and principles are described, which provide hybridization of MAS and MoM. Image of objects is effectively applied for the solution of the particular problem
Endogenous and exogenous testosterone and the risk of prostate cancer and increased prostate-specific antigen (PSA) level: a meta-analysis
Objective: To review and quantify the association between endogenous and exogenoustestosterone and prostate-specific antigen (PSA) and prostate cancer. Methods: Literature searches were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Prospectivecohort studies that reported data on the associations between endogenous testosterone and prostate cancer, and placebo-controlled randomized trials of testosterone replacement therapy (TRT) that reported data on PSA and/or prostate cancer cases were retained. Meta-analyses were performed using random-effects models, with tests for publication bias and heterogeneity. Results: Twenty estimates were included in a meta-analysis, which produced a summary relative risk (SRR) of prostate cancer for an increase of 5 nmol/L of testosterone of 0.99 (95% confidence interval [CI] 0.96, 1.02) without heterogeneity (I2 = 0%).Based on 26 trials, the overall difference in PSA levels after onset of use of TRT was 0.10 ng/mL (-0.28, 0.48). Results were similar when conducting heterogeneity analyses by mode of administration, region, age at baseline, baseline testosterone, trial duration, type of patients and type of TRT. The SRR of prostate cancer as an adverse effect from 11 TRT trials was 0.87 (95% CI0.30; 2.50). Results were consistent across studies. Conclusions: Prostate cancer appears to be unrelated to endogenous testosterone levels. TRT for symptomatic hypogonadism does not appear to increase PSA levels nor the risk of prostate cancer development. The current data are reassuring, although some caution is essential until multiple studies with longer follow-up are available
LINE-1 Methylation Levels in Leukocyte DNA and Risk of Renal Cell Cancer
Leukocyte global DNA methylation levels are currently being considered as biomarkers of cancer susceptibility and have been associated with risk of several cancers. In this study, we aimed to examine the association between long interspersed nuclear elements (LINE-1) methylation levels, as a biomarker of global DNA methylation in blood cell DNA, and renal cell cancer risk.LINE-1 methylation of bisulfite-converted genomic DNA isolated from leukocytes was quantified by pyrosequencing measured in triplicate, and averaged across 4 CpG sites. A total of 328 RCC cases and 654 controls frequency-matched(2∶1) on age(±5years), sex and study center, from a large case-control study conducted in Central and Eastern Europe were evaluated.LINE-1 methylation levels were significantly higher in RCC cases with a median of 81.97% (interquartile range[IQR]: 80.84–83.47) compared to 81.67% (IQR: 80.35–83.03) among controls (p = 0.003, Wilcoxon). Compared to the lowest LINE-1 methylation quartile(Q1), the adjusted ORs for increasing methylation quartiles were as follows: OR(Q2) = 1.84(1.20−2.81), OR(Q3) = 1.72(1.11−2.65) and OR(Q4) = 2.06(1.34−3.17), with a p-trend = 0.004. The association was stronger among current smokers (p-trend<0.001) than former or never smokers (p-interaction = 0.03). To eliminate the possibility of selection bias among controls, the relationship between LINE-1 methylation and smoking was evaluated and confirmed in a case-only analysis, as well.Higher levels of LINE-1 methylation appear to be positively associated with RCC risk, particularly among current smokers. Further investigations using both post- and pre-diagnostic genomic DNA is warranted to confirm findings and will be necessary to determine whether the observed differences occur prior to, or as a result of carcinogenesis
Genetic Contributions to the Association between Adult Height and Head and Neck Cancer : A Mendelian Randomization Analysis
Acknowledgements: The authors thank the Italian Association for Research on Cancer (AIRC, IG 2013 n. 14211) and the PRECeDI project (Marie Skłodowska-Curie Research and Innovation Staff Exchange - RISE N°645740) for supporting the work of Roberta Pastorino and Anna Puggina.Peer reviewedPublisher PD
Socio-demographic Predictors of Dimensions of the AUDIT Score in A Population Sample of Working-age Men in Izhevsk, Russia
Aims: To investigate the relationship between socio-demographic factors and alcohol drinking patterns identified through a formal analysis of the factor structure of the Alcohol Use Disorders Identification Test (AUDIT) score in a population sample of working-age men in Russia. Methods: In 2008–2009, a sample of 1005 men aged 25–59 years living in Izhevsk, Russia were interviewed and information collected about socio-demographic circumstances. Responses to the AUDIT questions were obtained through a self-completed questionnaire. Latent dimensions of the AUDIT score were determined using confirmatory factor analysis and expressed as standard deviation (SD) units. Structural equation modelling was used to estimate the strength of association of these dimensions with socio-demographic variables. Results: The AUDIT was found to have a two-factor structure: alcohol consumption and alcohol-related problems. Both dimensions were higher in men who were unemployed seeking work compared with those in regular paid employment. For consumption, there was a difference of 0.59 SDs, (95% confidence interval (CI): 0.23, 0.88) and for alcohol-related problems one of 0.66 SD (95% CI: 0.31, 1.00). Alcohol-related problems were greater among less educated compared with more educated men (P-value for trend = 0.05), while consumption was not related to education. Similar results were found for associations with an amenity index based on car ownership and central heating. Neither dimension was associated with marital status. While we found evidence that the consumption component of AUDIT was underestimated, this did not appear to explain the associations of this dimension with socio-demographic factors. Conclusions: Education and amenity index, both measures of socio-economic position, were inversely associated with alcohol-related problems but not with consumption. This discordance suggests that self-reported questions on frequency and volume may be less sensitive markers of socio-economic variation in drinking than are questions about dependence and harm. Further investigation of the validity of the consumption component of AUDIT in Russia is warranted as it appears that the concept of a standard ‘drink’ as used in the instrument is not understood
Alcohol and fatal life trajectories in Russia: understanding narrative accounts of premature male death in the family
Background: In the post-Soviet period, Russian working-age men have suffered unusually high mortality rates. Earlier quantitative work found that part of this is attributable to hazardous and harmful patterns of alcohol consumption, which increased in the period of transition at a time of massive social and economic disruption and uncertainty. However, there has been very little work done to document and understand in detail the downward life trajectories of individual men who died prematurely from alcohol-related conditions. Building on an earlier case-control study, this unique qualitative study investigates the perceived interplay between men's drinking careers, their employment and family history, health and eventual death.Methods: In-depth interviews were conducted with close relatives (most often the widow) of 19 men who died between 2003 and 2005 aged 25-54 years whose close relatives reported that alcohol contributed to their death. The study was conducted in a typical medium-sized Russian city. The relative's accounts were analysed using thematic content analysis.Results: The accounts describe how hazardous drinking both contributed to serious employment, family and health problems, and was simultaneously used as a coping mechanism to deal with life crises and a decline in social status. The interviews highlighted the importance of the workplace and employment status for shaping men's drinking patterns. Common themes emerged around a culture of drinking in the workplace, peer pressure from colleagues to drink, use of alcohol as remuneration, consuming non-beverage alcohols,Russian-specific drinking patterns, attitudes to treatment, and passive attitudes towards health and drinking.Conclusions: The study provides a unique insight into the personal decline that lies behind the extremely high working-age mortality due to heavy drinking in Russia, and highlights how health status and hazardous drinking are often closely intertwined with economic and social functioning. Descriptions of the development of drinking careers, hazardous drinking patterns and treatment experiences can be used to plan effective interventions relevant in the Russian context
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