A wideband trapezoidal dielectric resonator antenna with circular polarization

A new design of a circularly-polarized (CP) trapezoidal dielectric resonator antenna (DRA) for wideband wireless application is presented. A single-layered feed is used to excite the trapezoidal shaped dielectric resonator to increase resonant frequency and axial ratio. Besides its structure simplicity, ease of fabrication and low-cost, the proposed antenna features good measured impedance bandwidth, 87.3% at 4.21 GHz to 10.72 GHz frequency bands. Moreover, the antenna also produces 3-dB axial ratio bandwidth of about 710 MHz from 5.17 GHz to 5.88 GHz. The overall size of DRA is 21 mm × 35 mm, which is suitable for mobile devices. Parametric study and measurement results are presented and discussed. Very good agreement is demonstrated between simulated and measured results

Wideband P-Shaped Dielectric Resonator Antenna

A novel P-shaped dielectric resonator antenna (DRA) is presented and investigated for wideband wireless application. By using P-shaped resonator, a wideband impedance bandwidth of 80% from 3.5 to 8.2 GHz is achieved. The antenna covers all of wireless systems like C-band, 5.2, 5.5 & 5.8 GHz-WLAN & WiMax. The proposed antenna has a low profile and the thickness of the resonator is only 5.12 mm, which is 0.06-0.14 free space wavelength. A parametric study is presented. The proposed DRA is built and the characteristics of the antenna are measured. Very good agreement between numerical and measured results is obtained

Can we rely on public data as a source of information for cancer registry in developing countries?

Background/aims: Although a "hospital-based cancer registry" is important in improving patient care, a "population-based cancer registry" with emphasis on epidemiology is important in allocating health care resources and prioritizing public health programs. Because of its reliance on retrieved clinical and para-clinical documents, there is some limitation in registering all cancer incidents in this system, especially in developing countries. In this study we examined the possibility of using public data as a complementary source of information for recording cancers in a population-based cancer registry. Methods: Along with the annual census in rural areas, a survey was performed in Golestan province in March 2004 to identify public awareness about cancer incidents in the community. Individuals were questioned about history of cancer in their close relatives during the last two years. Those who reported cancer in their relatives were also asked to name the main organ of involvement. A similar list was retrieved from the cancer registry at the Ministry of Health in Gorgan, and cases with upper GI (esophagus and gastric) cancer diagnosis from 21 March 2002 through 20 March 2004 were selected for this study. Finally, these two lists were compared for examining accuracy of the collected data. Results: We included 137 cases in our study with rural residence and known addresses. Only 35 (25.5%) cases were reported by the relatives and among them only 20 (57.1%) relatives correctly reported the tumor location. Although we found a difference in accurate reporting of cancer incidents by year of diagnosis (more correct cases reported during the second versus the first year), the difference was not statistically significant between the two years. Conclusion: In this study, we examined the possibility of using public awareness about cancer incidents as a complementary source of information for a population-based cancer registry. We found that this approach is not ideal for reducing limitations. Therefore, we recommend a nationwide cancer registry to record all cancer-related information at the time of diagnosis. This strategy will reduce the need for performing retrospective surveys in collecting cancer-related information

A New Wideband Circularly Polarized Dielectric Resonator Antenna

A wideband and compact circularly polarized (CP) C-shaped dielectric resonator antenna (DRA) is presented. The proposed C-shaped DR is excited by a simple stripe line connected to a coplanar waveguide (CPW) feeding line. The C-shaped DRA is circularly polarized with 19% axial ratio (AR) bandwidth. It is found that the CP bandwidth can be expanded by using a narrow short circuit strip. The final design achieves CP with 50% AR bandwidth. The proposed circularly polarized DRA (CPDRA) with good radiation characteristics offers an impedance bandwidth of 58% between 3.45 and 6.26 GHz for VSWR ≤ 2. The proposed DRA is fabricated and tested. Very good agreement between simulated and measured results is obtained

Hepatitis B/C virus co-infection in Iran: A seroepidemiological study

Background/aims: As hepatitis B and C virus have the same transmission routes, dual infection may occur. The aim of this study was to determine the seroprevalence of HCV in HBsAg-positive subjects. Methods: 139 HBsAg-positive subjects were enrolled in the study. Serum samples were tested using ELISA method for anti-HCV antibodies. Chi-square and Fisher's exact tests were used to compare the proportions. Results: There were 68 (48.9%) males and 71 (51.1%) females. The mean age was 41.89±11.30 years. One case was excluded because of inadequate blood sampling. Anti-HCV antibody was positive in 17 (12.3%) of the 138 remaining subjects. Seropositivity of HCV was similar between female and male patients (p=0.69). Conclusion: The seroprevalence of co-infection with hepatitis B virus and hepatitis C virus in our study was higher than such reports from some countries (Italy), but was in line with worldwide prevalence (>10%)

Esophageal cancer in Iranian Turkmens: An ethnic disparity concern

The association between ethnic diversity in Turkmen population with esophageal cancer incidence in Iranian Turkmens (Golestan province) was trying to explore in the present study. This is a cross sectional study in Turkmen patients with confirmed diagnosis of esophageal cancer between 2002 through 2003 at a referral clinic in Gonbad. One hundred and six Turkmen patients, diagnosed with esophageal cancer by endoscopy and biopsy, were included. Demographic factors (sex and age), cancer histology (SCC and adenocarcinoma), tumor origin (upper 3rd, middle 3rd and lower 3rd of esophagus) and patients' contact numbers were retrieved and the patients were categorized into five different groups based on their ethnicity: Ahtahbai, Jafarbai, Googlan, others and unidentified ethnic group. Incidence rate was estimated based on the number of patients and population of each ethnic group. Descriptive statistics was performed and data were analyzed by Kruskal-Wallis Test for continuous variables and Chi-square Test for categorical variables. A total of 106 Turkmen patients with mean age of 64.22±12.12 (61 male and 45 female) were included in this study. Frequency for each ethnic group was identified as: Ahtahbai (n = 31, 29.2%), Googlan (n = 30, 28.3%), Jafarbai (n = 27, 25.5%), others (n = 7, 6.6%) and unidentified ethnic group (n = 11,10.4%). The mean age and gender were not significantly different between these ethnic groups. Heterogeneity was found within Turkmen population, Ahthabai having least and Googlan highest esophageal cancer incidence rate. As esophageal cancer is very common in Turkmen population and with the high incidence rate in Googlan, this ethnic group needs to be more targeted for the esophageal cancer-screening programme. Further population-based studies can better explore possible factors in different Turkmen ethnic groups

Long-term interleukin-6 levels and subsequent risk of coronary heart disease: Two new prospective studies and a systematic review

Background The relevance to coronary heart disease (CHD) of cytokines that govern inflammatory cascades, such as interleukin-6 (IL-6), may be underestimated because such mediators are short acting and prone to fluctuations. We evaluated associations of long-term circulating IL-6 levels with CHD risk (defined as nonfatal myocardial infarction [MI] or fatal CHD) in two population-based cohorts, involving serial measurements to enable correction for within-person variability. We updated a systematic review to put the new findings in context. Methods and Findings Measurements were made in samples obtained at baseline from 2,138 patients who had a first-ever nonfatal MI or died of CHD during follow-up, and from 4,267 controls in two cohorts comprising 24,230 participants. Correction for within-person variability was made using data from repeat measurements taken several years apart in several hundred participants. The year-to-year variability of IL-6 values within individuals was relatively high (regression dilution ratios of 0.41, 95% confidence interval [CI] 0.28-0.53, over 4 y, and 0.35, 95% CI 0.23-0.48, over 12 y). Ignoring this variability, we found an odds ratio for CHD, adjusted for several established risk factors, of 1.46 (95% CI 1.29-1.65) per 2 standard deviation (SD) increase of baseline IL-6 values, similar to that for baseline C-reactive protein. After correction for within-person variability, the odds ratio for CHD was 2.14 (95% CI 1.45-3.15) with long-term average ("usual'') IL-6, similar to those for some established risk factors. Increasing IL-6 levels were associated with progressively increasing CHD risk. An updated systematic review of electronic databases and other sources identified 15 relevant previous population-based prospective studies of IL-6 and clinical coronary outcomes (i.e., MI or coronary death). Including the two current studies, the 17 available prospective studies gave a combined odds ratio of 1.61 (95% CI 1.42-1.83) per 2 SD increase in baseline IL-6 (corresponding to an odds ratio of 3.34 [95% CI 2.45-4.56] per 2 SD increase in usual [long-term average] IL-6 levels). Conclusions Long-term IL-6 levels are associated with CHD risk about as strongly as are some major established risk factors, but causality remains uncertain. These findings highlight the potential relevance of IL-6-mediated pathways to CH

Genetically determined height and coronary artery disease.

BACKGROUND: The nature and underlying mechanisms of an inverse association between adult height and the risk of coronary artery disease (CAD) are unclear. METHODS: We used a genetic approach to investigate the association between height and CAD, using 180 height-associated genetic variants. We tested the association between a change in genetically determined height of 1 SD (6.5 cm) with the risk of CAD in 65,066 cases and 128,383 controls. Using individual-level genotype data from 18,249 persons, we also examined the risk of CAD associated with the presence of various numbers of height-associated alleles. To identify putative mechanisms, we analyzed whether genetically determined height was associated with known cardiovascular risk factors and performed a pathway analysis of the height-associated genes. RESULTS: We observed a relative increase of 13.5% (95% confidence interval [CI], 5.4 to 22.1; P<0.001) in the risk of CAD per 1-SD decrease in genetically determined height. There was a graded relationship between the presence of an increased number of height-raising variants and a reduced risk of CAD (odds ratio for height quartile 4 versus quartile 1, 0.74; 95% CI, 0.68 to 0.84; P<0.001). Of the 12 risk factors that we studied, we observed significant associations only with levels of low-density lipoprotein cholesterol and triglycerides (accounting for approximately 30% of the association). We identified several overlapping pathways involving genes associated with both development and atherosclerosis. CONCLUSIONS: There is a primary association between a genetically determined shorter height and an increased risk of CAD, a link that is partly explained by the association between shorter height and an adverse lipid profile. Shared biologic processes that determine achieved height and the development of atherosclerosis may explain some of the association. (Funded by the British Heart Foundation and others.)

HBV/HCV co-infection in Iran: A seroepidemiological based study

The aim of this study was to determine the seroprevalence of HCV in HBsAg positive subjects. In a population based single stage cluster sampling in Golestan province of Iran, 139 HBsAg positive subjects were detected and enrolled in the study. Serum samples were tested using ELISA method for anti-HCV antibodies. Chi-square and Fishers exact tests were used to compare the proportions. There were 68(48.9%) male and 71(51.1 %) female. The mean age was 41.89±11.30 years (25-64 years). One case was excluded because of inadequate blood sampling. Anti-HCV antibody was positive in 17(12.3%) of 138 remaining subjects. Seropositivity of HCV in female was higher than male (14.1% versus 10.4%, respectively) but the difference was not statistically significant (p = 0.52). No significant relationship was seen between Anti-HCV seroprevalence and demographic factors such as age, place of residence and marital status. The seroprevalence of co-infection with HBV and HCV in our study was higher than such reports from some countries (Italy); but it was in line with worldwide prevalence (>10%). A careful longitudinal evaluation of the viremia levels of both HBV/HCV viruses is essential for making a correct diagnosis and tailoring the appropriate therapeutic schedule in co-infected patients. © 2006 Asian Network for Scientific Information

Inflammatory cytokines and risk of coronary heart disease: new prospective study and updated meta-analysis.

AIMS: Because low-grade inflammation may play a role in the pathogenesis of coronary heart disease (CHD), and pro-inflammatory cytokines govern inflammatory cascades, this study aimed to assess the associations of several pro-inflammatory cytokines and CHD risk in a new prospective study, including meta-analysis of prospective studies. METHODS AND RESULTS: Interleukin-6 (IL-6), IL-18, matrix metalloproteinase-9 (MMP-9), soluble CD40 ligand (sCD40L), and tumour necrosis factor-α (TNF-α) were measured at baseline in a case-cohort study of 1514 participants and 833 incident CHD events within population-based prospective cohorts at the Danish Research Centre for Prevention and Health. Age- and sex-adjusted hazard ratios (HRs) for CHD per 1-SD higher log-transformed baseline levels were: 1.37 (95% CI: 1.21-1.54) for IL-6, 1.26 (1.11-1.44) for IL-18, 1.30 (1.16-1.46) for MMP-9, 1.01 (0.89-1.15) for sCD40L, and 1.13 (1.01-1.27) for TNF-α. Multivariable adjustment for conventional vascular risk factors attenuated the HRs to: 1.26 (1.08-1.46) for IL-6, 1.12 (0.95-1.31) for IL-18, 1.21 (1.05-1.39) for MMP-9, 0.93 (0.78-1.11) for sCD40L, and 1.14 (1.00-1.31) for TNF-α. In meta-analysis of up to 29 population-based prospective studies, adjusted relative risks for non-fatal MI or CHD death per 1-SD higher levels were: 1.25 (1.19-1.32) for IL-6; 1.13 (1.05-1.20) for IL-18; 1.07 (0.97-1.19) for MMP-9; 1.07 (0.95-1.21) for sCD40L; and 1.17 (1.09-1.25) for TNF-α. CONCLUSIONS: Several different pro-inflammatory cytokines are each associated with CHD risk independent of conventional risk factors and in an approximately log-linear manner. The findings lend support to the inflammation hypothesis in vascular disease, but further studies are needed to assess causality.This work was supported by a grant from the British Heart Foundation (RG/08/014), the U.K. Medical Research Council, and the U.K. National Institute of Health Research Cambridge Biomedical Research Centre.This is the accepted manuscript. The final version is available from OUP at http://eurheartj.oxfordjournals.org/content/35/9/578