16 research outputs found

    A Study of Different Substrate Material on Air Gap Radial Line Slot Array (RLSA) Antenna at 28 GHz

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    This paper compared the performance of the conventional Radial line slot array (RLSA) antenna structure. Two different substrates of RLSA antennas were used: The FR4 with the relative permittivity (εr) value of 4.5 and the Duroid/RT5880 with the relative permittivity (εr) value of 2.2. Both substrates had their own thickness, where the Rogers RT Duroid 5880 was thinner with the value of 0.254 mm compared to FR4 which was 1.600 mm. There were two antenna cavities, which were the FR4 hybrid with air gap and the Duroid/RT5880 hybrid with air gap. Based on different substrate, this RLSA antenna was simulated using the CST Microwave Studio simulation software and measured using the Vector Network Analyzer (VNA) equipment that can measure the frequency range (10.0 MHz to 50.0 GHz). Moreover, this RLSA antenna was presented, experimented and measured for millimeter wave frequency, which is within the frequency range (24.0 GHz to 32.0 GHz). In the middle of the rectangular, slots on radiating plate, located with fed coated of 50 Ω SSMA connector as a coaxial to waveguide transition frequency reconfigurable millimeter-wave antenna for 5G networks is presented. The results of the simulation and measurement of this RLSA antenna with different substrates show the S11 and wider value of impedance bandwidth performance in millimeter wave frequency

    Repositioning of the global epicentre of non-optimal cholesterol

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    High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health4,5. However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol—which is a marker of cardiovascular risk—changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million–4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.</p

    Repositioning of the global epicentre of non-optimal cholesterol

    Get PDF
    High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health4,5. However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol�which is a marker of cardiovascular risk�changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95 credible interval 3.7 million�4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world. © 2020, The Author(s), under exclusive licence to Springer Nature Limited

    Rising rural body-mass index is the main driver of the global obesity epidemic in adults

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    Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities 1,2 . This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity 3�6 . Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55 of the global rise in mean BMI from 1985 to 2017�and more than 80 in some low- and middle-income regions�was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing�and in some countries reversal�of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories. © 2019, The Author(s)

    Vascular cell adhesion molecule-1 (VCAM-1) in Graves’ disease: its association to thyroid status and thyroid receptor stimulating antibodies

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    Soluble vascular cell adhesion molecule-1(sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) have been shown to be elevated in patients with Graves’ disease and may play significant roles in the pathogenesis of the disease. The objective of this study was to measure the levels of sVCAM-1, sICAM-1, IL-6 and thyroid receptor stimulating antibodies (TRAb) in a cohort of hyperthyroid patients and determine their associations to thyroid hormones status, before and after 3 months therapy with carbimazole. Patients were given fixed daily dose of 20 mg carbimazole for 3 months and blood samples were collected at baseline and end of the study. Thirty-eight patients were recruited from the Endocrine Clinic, Hospital Universiti Kebangsaan Malaysia, consisting of 26 females and 12 males, age ranging from 16 to 65 years. Blood samples collected before and at end of study were analysed for TSH, Free T3, Free T4, thyroid receptor stimulating antibodies (TRAb), sVCAM-1, sICAM-1 and IL-6. TRAb level of ≤10 U/L was taken to be negative, while TRAb level of >10 U/L was considered as positive. Twenty-six patients (68%) were TRAb positive (TRAb+) and 12 patients (30%) were TRAb negative (TRAb-). Median TRAb in TRAb+ patients was 23 U/L at baseline, declining to 16.7 U/L (p<0.001) in the third 3 month. Serum sVCAM-1 levels were significantly elevated in TRAb+ patients compared to TRAb- (860 versus 499 ng/mL, p<0.001). The level decreased significantly to 537 ng/mL with treatment but remained higher than in TRAb- patients (p=0.003). Irrespective of TRAb status, all but one patient had elevated serum sICAM-1 levels that remained unaffected by carbimazole therapy. In contrast, IL-6 levels of hyperthyroid patients were within the reference range of 1.4-14.1 pg/mL. Baseline and post-treatment sVCAM-1, and not TRAb levels, were significantly correlated to thyroid hormones. Compared to other inflammatory markers, sVCAM-1 showed significant correlation to thyroid stimulating antibodies and was most sensitive to changes in thyroid status. The significance of these findings in relation to Graves’ disease warrants further investigation

    Hypoglycemia awareness among insulin-treated patients with diabetes in Malaysia: A cohort subanalysis of the HAT study

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    Aims The present Malaysian cohort analysis determined the prevalence of hypoglycemia among patients with type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM) attending primary care- or hospital-based diabetes clinics in Malaysia and their awareness of the symptoms of hypoglycemia. Methods The Hypoglycemia Assessment Tool (HAT) study was a non-interventional, 6-month retrospective and 4-week prospective analysis of hypoglycemic events in 24 countries, using self-assessment questionnaires and diaries among patients with T1DM/T2DM aged ≥18 years, using insulin for >12 months. This report focuses on prospective data, as they are less prone to recall bias. Results There were 1153 participants in the Malaysian cohort (114 T1DM; 1039 T2DM). In the prospective period, 50.4% and 33.4% of patients reported ≥1 hypoglycemic events, with estimated rates of 20.3 and 13.1 events per patient-year of exposure in patients with T1DM and T2DM, respectively. 24.8% and 16.1% of patients with T1DM or T2DM, respectively, reported ≥1 nocturnal hypoglycemic event. The majority of patients (96.5%, T1DM; 91.8%, T2DM) knew what hypoglycemia was prior to the study. Impaired awareness was present in 48.0% (T1DM) and 36.9% (T2DM) of patients. In the prospective period, 50% of patients with T1DM or T2DM consulted a doctor or nurse following a hypoglycemia episode. Conclusions Half of patients with T1DM and a third of patients with T2DM reported ≥1 hypoglycemic event during the prospective period. Although the majority of patients knew the typical features of hypoglycemia, many reported impaired ability to recognize symptoms in real life. The present findings highlight the importance of patient education and physician awareness in dealing with hypoglycemia, in particular the burden of hypoglycemic unawareness. Clinical trial number This trial was registered at www.clinicaltrials.gov as NCT01696266 on 26 September 2012

    Profiles and factors associated with poor glycemic control among inpatients with diabetes mellitus type 2 as a primary diagnosis in a teaching hospital

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    Context: Diabetes mellitus is a growing health problem in most countries. In Malaysia, there was an increase in prevalence over the years. This makes diabetes also a growing concern in Malaysia, which warrants strengthening of the prevention and control programme. Aims: This paper aims to describe the profiles of diabetes mellitus type 2 in tertiary setting and to identify the risk factors for high level of HbA1c among the study population. The findings will give a glimpse on current status of diabetes in our country and may reflect the achievement of the country in combating this disease. Settings and Design: A cross-sectional study was conducted in UKM Medical Centre. Methods and Material: Medical records of patient with E11 ICD-10 code were collected using Case Report Form. Statistical Analysis Used: Descriptive analysis done of mean and median while test of association were done using Spearman correlation and logistic regression. Results: The results showed that majority of inpatients of DMT2 showed mean age of 58.8 + 12.6 years and most were males (56.7%) with secondary level of education (41.7%). Median duration of disease was 12.0 + 11.0 years with median HbA1c level of 8.9 ± 4.4%. Only small proportion of patients achieved the desired level of HbA1c <6.5% (21.3%) and significant association was found with tertiary level of education [AOR=0.10, 95%CI=0.01-0.96] and with type of anti-diabetic therapy [AOR=15.90, 95%CI=2.03-124.30]. Conclusions: In conclusion, diabetes mellitus type 2 inpatients still showed unsatisfactory glycemic control and holistic approach using health education should be advocated continuously in the future in view of education being one of the predictors for the good HbA1c outcome

    Derivation of simple muscle fatigue index for biceps muscle based on surface electromyography temporal characteristics

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    Biceps brachii muscle which attached to the forearm bone is one of the important muscles to the athletes who involve in sports like badminton, tennis and volleyball. Repetition of the arm such as throwing and hitting can lead to muscle fatigue. This physiological phenomenon needs to be monitored and well controlled especially in athletes training. The purpose of this study was to formulate a simple muscle fatigue index for the biceps brachii muscles. Ten male badminton players were chosen to be the subjects for this study. Each subject was asked to do dynamic contraction by lifting 5 kilogram dumbbell. This exercise is called biceps curl exercise and the subjects were asked to repeat the task for one minute and thirty seconds. The electromyogram signal was recorded using Neuroprax EEG device. For that purpose, monopolar surface electrodes were attached to the biceps muscle of the subject. The electromyogram signals were then processed using MATLAB software. Four parameters in time domain were extracted; Zero Crossings (ZC), Root Mean Square (RMS), Mean Absolute Value (MAV), and Variance (VAR). Except for zero crossings (ZC), all other parameters showed significant difference between fatigue signal and non-fatigue signal (p-value < 0.001). RMS was found to correlate very well with MAV (0.999). The study concludes that several temporal characteristics from electromyogram signal could be used in the formulation of biceps muscle fatigue index, supporting its use in monitoring muscle endurance

    Prevalence of overweight and obesity among adult Malaysians: an update

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    A total of 4428 adults (>18 years old) from 5 different selected regions in Peninsular and East Malaysia participated in this health survey. Using World Health Organization recommendations for body mass index (HMI), the prevalence of overweight and obesity were found to be 33.6 (95 CI= 32.2, 35.0) and 19.5 (95 CI= 18.3, 20.7) respectively. There were more females who were obese (22.5, 95 CI=20.9, 24.0) compared to males (14.1, 95 CI=12.3, 15.9). Highest prevalence of obesity were among the Indians (24.6, 95 CI=20.3, 29.3), followed closely by the Malays (23.2, 95 CI=21.6, 24.8) and lowest prevalence was among the Chinese subjects (8.2, 95 CI=6.2, 10.6). More than 43 of the 531 younger subjects (30 kg/m(2)) who initially claimed to have no diabetes. This study highlights a need for more active, inter-sectoral participation advocating a health-promoting environment in order to combat obesity in this country
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