Thru reflect line calibration for empty substrate integrated waveguide with microstrip transitions

In past years, a great number of substrate integrated circuits have been developed. Among these new transmission lines, the substrate integrated waveguide (SIW) has received special attention. Although the quality factor and losses of these new integrated lines are better than the planar circuits, these characteristics are worst than in the case of waveguides, mainly due to the presence of dielectric substrate. To improve the performance of the integrated circuits, a new methodology for manufacturing the empty waveguides, without dielectric substrate, but at the same time completely integrated in a planar substrate, has been recently proposed, resulting in the novel empty SIW (ESIW). A low-cost and easy to manufacture thru reflect line calibration kit for de-embedding the effect of connectors and transitions when measuring ESIW devices is presented. Results prove the high quality of this calibration kit.Fernández Berlanga, M.; Ballesteros Garrido, J.; Martínez Cano, L.; Esteban González, H.; Belenguer Martínez, A. (2015). Thru reflect line calibration for empty substrate integrated waveguide with microstrip transitions. Electronics Letters. 51(16):1274-1276. doi:10.1049/el.2015.1393S127412765116Belenguer, A., Esteban, H., & Boria, V. E. (2014). Novel Empty Substrate Integrated Waveguide for High-Performance Microwave Integrated Circuits. IEEE Transactions on Microwave Theory and Techniques, 62(4), 832-839. doi:10.1109/tmtt.2014.2309637Deslandes, D., & Ke Wu. (2005). Analysis and design of current probe transition from grounded coplanar to substrate integrated rectangular waveguides. IEEE Transactions on Microwave Theory and Techniques, 53(8), 2487-2494. doi:10.1109/tmtt.2005.852778Engen, G. F., & Hoer, C. A. (1979). Thru-Reflect-Line: An Improved Technique for Calibrating the Dual Six-Port Automatic Network Analyzer. IEEE Transactions on Microwave Theory and Techniques, 27(12), 987-993. doi:10.1109/tmtt.1979.1129778Caballero, E. D., Boria, V. E., Belenguer, A., & Esteban, H. (2013). Thru-reflect-line calibration for substrate integrated waveguide devices with tapered microstrip transitions. Electronics Letters, 49(2), 132-133. doi:10.1049/el.2012.302

Thru-reflect-line calibration for substrate integrated waveguide devices with tapered microstrip transitions

One of the main problems when exciting or measuring substrate integrated waveguide (SIW) devices lies in the need of a good interconnection with planar structures. In this reported work, the negative effects produced by the connectors and the tapered microstrip-to-SIW transitions are de-embedded from the measurements of the SIW structure by a thru-reflect-line calibration with an adequate and cheap SIW calibration kit.Díaz Caballero, E.; Belenguer Martínez, Á.; Esteban González, H.; Boria Esbert, VE. (2013). Thru-reflect-line calibration for substrate integrated waveguide devices with tapered microstrip transitions. Electronics Letters. 49(2):132-133. doi:10.1049/el.2012.3027S132133492Deslandes, D., & Wu, K. (2001). Integrated microstrip and rectangular waveguide in planar form. IEEE Microwave and Wireless Components Letters, 11(2), 68-70. doi:10.1109/7260.914305Henry, M., Free, C. E., Izqueirdo, B. S., Batchelor, J., & Young, P. (2009). Millimeter Wave Substrate Integrated Waveguide Antennas: Design and Fabrication Analysis. IEEE Transactions on Advanced Packaging, 32(1), 93-100. doi:10.1109/tadvp.2008.2011284Chen, X.-P., Wu, K., & Li, Z.-L. (2007). Dual-Band and Triple-Band Substrate Integrated Waveguide Filters With Chebyshev and Quasi-Elliptic Responses. IEEE Transactions on Microwave Theory and Techniques, 55(12), 2569-2578. doi:10.1109/tmtt.2007.909603Deslandes, D., & Ke Wu. (2005). Analysis and design of current probe transition from grounded coplanar to substrate integrated rectangular waveguides. IEEE Transactions on Microwave Theory and Techniques, 53(8), 2487-2494. doi:10.1109/tmtt.2005.852778Engen, G. F., & Hoer, C. A. (1979). Thru-Reflect-Line: An Improved Technique for Calibrating the Dual Six-Port Automatic Network Analyzer. IEEE Transactions on Microwave Theory and Techniques, 27(12), 987-993. doi:10.1109/tmtt.1979.1129778Chih-Jung Chen, & Tah-Hsiung Chu. (2009). Measurement of Noncoaxial Multiport Devices Up to the Intrinsic Ports. IEEE Transactions on Microwave Theory and Techniques, 57(5), 1230-1236. doi:10.1109/tmtt.2009.201735

Liver cirrhosis mortality at national and provincial levels in Iran between 1990 and 2015: A meta regression analysis

Background Liver cirrhosis mortality number has increased over the last decades. We aimed to estimate the liver cirrhosis mortality rate and its trends for the first time by sex, age, geographical distribution, and cause in Iran. Method Iranian Death Registration System, along with demographic (Complete and Summary Birth History, Maternal Age Cohort and Period methods) and statistical methods (Spatio-temporal and Gaussian process regression models) were used to address the incompleteness and misclassification and uncertainty of death registration system to estimate annual cirrhosis mortality rate. Percentages of deaths were proportionally redistributed into cirrhosis due to hepatitis B, C and alcohol use based on the data from the Global Burden of Disease (GBD) 2010 study. Results Liver cirrhosis mortality in elder patients was 12 times higher than that in younger patients at national level in 2015. Over the 26 years, liver cirrhosis mortality in males has increased more than that in females. Plus, the percentage of change in age adjusted mortality rate at provincial levels varied between decreases of 64.53 to nearly 17 increase. Mortality rate has increased until 2002 and then decreased until 2015.The province with highest mortality rate in 2015 has nearly two times greater rate compare to the lowest. More than 60 of liver cirrhosis mortality cases at national level are caused by hepatitis B and C infection. The rate of hepatitis B mortality is four times more than that from hepatitis C. Conclusion This study demonstrated an increasing and then decreasing pattern in cirrhosis mortality that could be due to national vaccination of hepatitis B program. However monitoring, early detection and treatment of risk factors of cirrhosis, mainly in high risk age groups and regions are essential. Cirrhosis mortality could be diminished by using new non-invasive methods of cirrhosis screening, hepatitis B vaccination, definite treatment of hepatitis C. © 2019 Rezaei et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Physical activity pattern in Iran:findings from STEPS 2021

Abstract Background: Insufficient physical activity (IPA) is a significant risk factor for various non-communicable diseases. The Iran action plan is a 20% reduction in IPA. Therefore, we aimed to describe the age and sex pattern of physical activity domains, IPA, the intensity of physical activity, sedentary behavior, and their associates at Iran’s national and provincial levels in 2021. Methods: This study used the data of the STEPwise Approach to NCD Risk Factor Surveillance (STEPS) 2021 in Iran. The STEPS study used the Global Physical Activity Questionnaire (GPAQ) version two developed by WHO for the assessment of physical activity, which included work, transport, and recreational activities domains. We showed and compared demographic and clinical characteristics of participants between males and females, using t-test and Chi-square test. A logistic regression model adjusted for residential areas, years of schooling, wealth index, age, marital status, and occupation has also been implemented. The results were presented as percentages and 95% confidence intervals (CI). Results: We included 27,874 participants with a mean (SD) age of 45.69 (15.91), among whom 12,479 (44.77%) were male. The mean prevalence of IPA for the whole population for all ages was 51.3% (50.62–51.98%). By sex, 41.93% (40.88–42.98%) and 57.87% (56.99–58.75%) of men and women had IPA, respectively. According to the physical activity domains, the age-standardized prevalence of no recreational activity was 79.40% (78.80–79.99%), no activity at work was 66.66% (65.99–67.32%), and no activity at transport was 49.40% (48.68–50.11%) for both sexes combined. Also, the overall age-standardized prevalence of sedentary behaviors was 50.82% (50.11–51.53%). Yazd province represented the highest prevalence of IPA (63.45%), while West Azerbaijan province represented the lowest prevalence (39.53%). Among both sexes, living in the urban area vs. rural area [adjusted OR: 1.44; (1.31–1.58)], married vs. single status [adjusted OR: 1.33; (1.16–1.53)], and wealth index of class 3 vs. class 1 [adjusted OR: 1.15; (1.01–1.30)] were significantly associated with a higher rate of IPA. Conclusions: The prevalence of IPA was considerably high in Iran. To achieve the predefined goal of reducing IPA, the health system should prioritize increasing physical activity, especially in urban areas and among females

Prevalence of plasma lipid abnormalities and associated risk factors among Iranian adults based on the findings from STEPs survey 2021

Abstract The study aimed to estimate the prevalence of lipid abnormalities in Iranian adults by demographic characterization, geographical distribution, and associated risk factors using national and sub-national representative samples of the STEPs 2021 survey in Iran. In this population-based household survey, a total of 18,119 individuals aged over 25 years provided blood samples for biochemical analysis. Dyslipidemia was defined by the presence of at least one of the lipid abnormalities of hypertriglyceridemia (≥ 150 mg/dL), hypercholesterolemia (≥ 200 mg/dL), high LDL-C (≥ 130 mg/dL), and low HDL-C (< 50 mg/dL in women, < 40 mg/dL in men), or self-reported use of lipid-lowering medications. Mixed dyslipidemia was characterized as the coexistence of high LDL-C with at least one of the hypertriglyceridemia and low HDL-C. The prevalence of each lipid abnormality was determined by each population strata, and the determinants of abnormal lipid levels were identified using a multiple logistic regression model. The prevalence was 39.7% for hypertriglyceridemia, 21.2% for hypercholesterolemia, 16.4% for high LDL-C, 68.4% for low HDL-C, and 81.0% for dyslipidemia. Hypercholesterolemia and low HDL-C were more prevalent in women, and hypertriglyceridemia was more prevalent in men. The prevalence of dyslipidemia was higher in women (OR = 1.8), obese (OR = 2.8) and overweight (OR = 2.3) persons, those residents in urban areas (OR = 1.1), those with inappropriate physical activity (OR = 1.2), patients with diabetes (OR = 2.7) and hypertension (OR = 1.9), and participants with a history (OR = 1.6) or familial history of CVDs (OR = 1.2). Mixed dyslipidemia prevalence was 13.6% in women and 11.4% in men (P < 0.05). The prevalence of lipid abnormalities was highly heterogeneous among provinces, and East Azarbaijan with 85.3% (81.5–89.1) and Golestan with 68.5% (64.8–72.2) had the highest and lowest prevalence of dyslipidemia, respectively. Although the prevalence of high cholesterol and LDL-C had a descending trend in the 2016–2021 period, the prevalence of dyslipidemia remained unchanged. There are modifiable risk factors associated with dyslipidemia that can be targeted by the primary healthcare system. To modify these risk factors and promote metabolic health in the country, action plans should come to action through a multi-sectoral and collaborative approach