45 research outputs found

    A Comparative Study for enhancing PV Penetration limit of a LV CIGRE Residential Network with Distributed Grid-Tie Single-Phase PV Systems

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    Photovoltaic distributed generation (PVDG) has seen tremendous growth in recent years, especially in the residential sector. Among other concerns, the voltage rise in AC networks is considered the most limiting factor in achieving increased PV penetration levels. A steady-state impact study is performed on a CIGRE low-voltage (LV) residential network. This paper compares six techniques to increase the PV penetration limit in the LV residential network, namely single-phase penetration (SPP), Distribution Scheme 1 (DS1), Distribution Scheme 2 (DS2), alternate phase penetration (APP), offline tap adjustment (OTA) and switched on-load tap adjustment (SOLTA). PSCAD software is used for this study. The best results are obtained for the DS2-SOLTA case that gives the minimum voltage magnitude and voltage unbalance in the system. The steady-state results are validated by a dynamic data study using measured solar irradiance and residential load data. A novel approach is also proposed for calculating the worst day from the data set. The obtained results verify the effectiveness of the proposed approach

    Iodine Content in Urine Samples among Malays and Aborigines

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    A study was conducted to compare the urinary iodine concentrations in populations from Pahang, Central Malaysia, with those in the capital city Kuala Lumpur, and to compare those of Malays from villages at Batu Talam, Batu Malim, FELDA Sungai Koyan and Hulu Sungai with neighboring aboriginal settlements at Lanai and Buntu. Two hundred and forty urine samples were collected randomly among the population (male 1 1 1 and female 129). The urinary iodine concentrations, measured by the ashing method, among Malays were as follows: Batu Talam 1.1-7.6 micrograms/dl, Batu Malim 1.4-6.6 micrograms/dl, FELDA Sungai Koyan 0.5-6.9 micrograms/dl and Hulu Sungai 0.6-9.9 micrograms/dl. Among aborigines, the urinary iodine levels were 0.1-2.9 micrograms/dl in Lanai and 1.7-6.5 micrograms/dl in Buntu. There was a significant difference in the levels of urinary iodine with regard to gender, but not regarding age. The aborigines had significantly lower iodine levels than Malays (P &#60; 0.001). This difference was also significant with regard to location. The urinary iodine content in Kuala Lumpur was the highest and that in the aboriginal Lanai village was the lowest. Thus, the study showed that the levels of iodine in the urine were influenced by ethnicity and geographic location.</p

    Utilisation of mussel shell ash and palm oil leaves ash as admixture in concrete

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    Mussel shell and palm oil leaves is a type of waste that generally undergo disposal process due to less- valuable materials. However, this waste is potentially to be used in concrete designing due to its cementing properties. Thus, this paper presenting the incorporation of mussel shell ash (MSA) and palm oil leaves ash (POLA) as an admixture in concrete. MSA and POLA were obtained through grounding, burning and sieving process. As total, 84 concrete samples were mixed with different proportions of POLA (0.5%, 1% and 1.5%), MSA (1% and 2%) and K for control samples. All the samples were cured for 7 days and 28 days. The study was carried out to measure its physical and mechanical properties such as compressive, split tensile and capillary absorption analysis. While, its materials properties (MSA and POLA) were identified through its specific gravity test. The results demonstrated that B5 (1.5% POLA + 1% MSA) gave a good performance in concrete compressive strength on 7 and 28 days. Besides that, B5 also indicates a lower capillary water absorption compared to other specimens. Whereas B6 indicates a higher value for density analysis. Overall, the experimental result indicates that B5 does not giving any adverse effect on the concrete performance. Thus, it is proved that the utilisation of MSA and POLA as cementing materials are applicable in improving concrete strength and its durability accordingly to the selected percentage

    Exploring the evidence base for national and regional policy interventions to combat resistance

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    The effectiveness of existing policies to control antimicrobial resistance is not yet fully understood. A strengthened evidence base is needed to inform effective policy interventions across countries with different income levels and the human health and animal sectors. We examine three policy domains—responsible use, surveillance, and infection prevention and control—and consider which will be the most effective at national and regional levels. Many complexities exist in the implementation of such policies across sectors and in varying political and regulatory environments. Therefore, we make recommendations for policy action, calling for comprehensive policy assessments, using standardised frameworks, of cost-effectiveness and generalisability. Such assessments are especially important in low-income and middle-income countries, and in the animal and environmental sectors. We also advocate a One Health approach that will enable the development of sensitive policies, accommodating the needs of each sector involved, and addressing concerns of specific countries and regions

    Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

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    Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

    COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

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    Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P &lt; 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

    A novel mutation in exon 5 of the low density lipoprotein receptor gene in a Malay family with familial hypercholesterolaemia (FH)

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    F�amilial hypercholesterolaemia (FH) is an autosomal dominant inherited disease of lipid metabolism caused by mutations in the low density lipoprotein receptor (LDLR) gene. FH is clinically characterised by an elevated concentration of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C), the presence of xanthomata and premature atherosclerosis. The objective of this study was to characterise the LDLR gene mutations in members of a family with FH. In total, 24 individuals were enrolled into this study. A proband from this family was diagnosed as FH based on the Simon Broome's criteria. Mutational screening was performed by polymerase chain reaction - denaturing gradient gel electrophoresis (PCR-DGGE) approach. Those bands that shifted on DGGE were subjected to DNA sequencing to confirm the mutation. We identified a base substitution, T to A at position 763 resulting in substitution of amino acid cysteine (C) to serine (S) at codon 234. This mutation was detected in exon 5 of the LDLR gene which involved the ligand binding domain and is designated as C234S mutation. This domain is important for the binding of LDLR to its ligand, apolipoprotein B100, in order to regulate the LDL catabolism through the LDLR mediated pathway. Mutation in this region may reduce the binding affinity of the LDLR to apolipoprotein B100. To our knowledge, this is a novel mutation worldwide. This mutation could possibly has important clinical implications in view of the high incidence of coronary artery disease (CAD) and sudden cardiac death (SCD) in the family

    Predictor of cardiovascular risks in end stage renal failure patients on maintenance dialysis

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    Objective: Cardiovascular disease (CVD) is the main cause of morbidity and premature mortality in end stage renal failure patients (ESRD) receiving dialysis. The aim of our study was to evaluate the impact of various risk factors in this group of high CVD risk patients in local population. Methods: We carried out a cross-sectional retrospective study in a single hospital. A total of 136 ESRF patients, consisted of 43 haemodialysis (HD) and 93 continuous ambulatory peritoneal dialysis (CAPD) patients, were recruited and followed up for 36 months duration. Midweek clinical and laboratory data were collected. The occurrence of existing and new CVD events was recorded. Results: Multiple Logistic Regression showed pre-existing cardiovascular event (odds ratio, 4.124; 95% confidence interval [CI], 0.990 to 17.187), elevated total cholesterol level (odds ratio, 0.550; 95% CI, 0.315 to 0.963), elevated serum phosphate level (odds ratio, 5.862; 95% CI, 1.041 to 33.024) and elevated random blood glucose level (odds ratio, 1.193; 95% CI, 1.012 to 1.406) were significantly associated with occurrence of CVD events. Conclusions: History of cardiovascular event before the initiation of dialysis, elevated level of serum phosphate and random blood glucose levels are the risk factors of CVD whereas paradoxically a high total cholesterol level has CVD protective effect towards the ESRF patients
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