Design of a ferrite rod antenna for harvesting energy from medium wave broadcast signals

Radio frequency (RF) energy harvesting is an emerging technology that has the potential to eliminate the need for batteries and reduce maintenance costs of sensing applications. The antenna is one of the critical components that determines its performance and while antenna design has been well researched for the purpose of communication, the design for RF energy harvesting applications has not been widely addressed. The authors present an optimised design for such an antenna for harvesting energy from medium wave broadcast transmissions. They derive and use a model for computing the optimal antenna configuration given application requirements on output voltage and power, material costs and physical dimensions. Design requirements for powering autonomous smart meters have been considered. The proposed approach was used to obtain the antenna configuration that is able to deliver 1 mW of power to 1 kΩ load at a distance of up to 9 km, sufficient to replace batteries on low-power sensing applications. Measurements using a prototype device have been used to verify the authors simulations

Single Nucleotide Polymorphisms (Snps) Of Low-Density Lipoprotein Receptor Gene (Ldlr) In Lipid Related Gene-Associated Familial Hypercholesterolaemia Among Iban And Bidayuh Ethnic Groups In Sarawakian Population: Preliminary Data Analysis

Objectives: Familial Hypercholesterolaemia (FH) is a genetic disease caused by defects in a number of variants, including low-density lipoprotein receptor gene (LDLR) that regulate plasma LDL-cholesterol concentrations. FH typically passed down through families in an autosomal dominant manner. That means one only needs to acquire the abnormal gene from one parent in order to be affected by the disease. FH has a worldwide prevalence of 0.2%, however it is considerably higher in some population because of a founder effect. This study was initiated as there is no FH data available in Sarawak. We aimed to determine the frequencies lipid related gene polymorphisms in Iban and Bidayuh ethnic groups in Sarawak, and its associations with lipid profiles. Methods: A total of 110 Iban and Bidayuh were recruited. Physical assessments were performed and two blood tubes were withdrawn. Subjects’ clinical blood lipid parameters were analyzed and DNA was extracted. Allele Specific-PCR of LDLR gene for two polymorphisms (c. 1060+7 T>C & c. 1706-55A>C) were categorized into homozygous wild, heterozygous and homozygous SNP. Agarose gel electrophoresis was performed and the data were analysed using SPSS. Results: Preliminary data shows that 99.1% have homozygous SNP and 0.9% have homozygous wild in c. 1060+7 T>C, while in c. 1706-55A>C: 66.4% have heterozygous SNP, 21.8% have homozygous SNP and 11.8% have homozygous wild. So far there is no significant association between SNPs and lipid profiles level among Iban and Bidayuh population in Sarawak. We also found out that the level of LDL mean is approximately and within the border line for all the categories of genotypes. The mean (SD) of LDL cholesterol level for c. 1060+7 T>C homozygous wild, homozygous SNP is 3.4 (0.00) and 3.2 (1.09) respectively while for c. 1706-55A>C heterozygous SNP, homozygous wild and homozygous SNP is 3.2 (1.05), 3.4 (1.03) and 3.3 (1.25) respectively. This might be due to the combined genotypes of variants within LDLR gene were detected. Conclusion: Preliminary findings from this ongoing research show that SNPs of the LDLR gene are present in the Iban and Bidayuh. Further works is needed to determine the linkage disequilibrium among variants of LDLR gene

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution.A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Diabetes mellitus: pathophysiological changes and therap

The use of imaging in patients post breast reconstruction

Aim To evaluate the usefulness of mammographic surveillance for asymptomatic patients and as a problem-solving tool in symptomatic patients with reconstructed breasts. Materials and methods The imaging records over 4 years identified 227 patients with a history of breast reconstruction post-mastectomy due to cancer. Clinical and imaging records were reviewed to evaluate the use of imaging in the follow-up management of these patients. Results Records showed that 116 (51%) of the patients identified underwent surveillance mammography of the reconstructed breast, in which one recurrent cancer was detected in an autologous tissue flap reconstruction (0.86% detection rate of non-palpable recurrent cancer), with a recall rate of 4%. One other patient had interval recurrence diagnosed following presentation with pain. Mammography of the contralateral breast only was performed in 111 patients. Fifty-four patients (24%) presented on 78 occasions with symptoms relating to the breast reconstructions, most commonly lump or swelling. Half of these patient episodes subsequently found no significant abnormality, and a further 29% had fat necrosis revealed on imaging. Four recurrent cancers were diagnosed. Conclusion There is insufficient evidence for recommending routine surveillance mammography for non-palpable recurrent cancer in the reconstructed breasts. Ultrasound and mammography are useful imaging techniques in the assessment of reconstructed breasts in the symptomatic setting. Fat necrosis is the most common benign finding on mammograms of reconstructed breasts, both in the surveillance and symptomatic groups

Surgery for left main spasm. Is it indicated?

10.1016/0167-5273(96)02604-6International Journal of Cardiology543213-216IJCD

Co-Existing Left Atrial Thrombus and Myxoma in Mitral Stenosis - A Diagnostic Challenge

Singapore Medical Journal40146-47SIMJ

Minimally invasive direct coronary artery bypass

Singapore Medical Journal40275-77SIMJ

Tissue engineered tri-leaflet heart valve - preliminary fabrication of biodegradable polymer scaffolds

Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings2748CEMB