19672 research outputs found
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Reduced graphene/nanostructured cobalt oxide nanocomposite for enhanced electrochemical performance of supercapacitor applications
No full textWe demonstrate the preparation of nanostructures cobalt oxide/reduced graphene oxide (Co3O4/rGO) nanocomposites by a simple one-step cost-effective hydrothermal technique for possible electrode materials in supercapacitor application. The X-ray diffraction patterns were employed to confirm the nanocomposite crystal system of Co3O4/rGO by demonstrating the existence of normal cubic spinel structure of Co3O4 in the matrix of Co3O4/rGO nanocomposite. FTIR and FT-Raman studies manifested the structural behaviour and quality of prepared Co3O4/rGO nanocomposite. The optical properties of the nanocomposite Co3O4/rGO have been investigated by UV absorption spectra. The SEM/TEM images showed that the Co3O4 nanoparticles in the Co3O4/rGO nanocomposites were covered over the surface of the rGO sheets. The electrical properties were analyzed in terms of real and imaginary permittivity, dielectric loss and AC conductivity. The electrocatalytic activities of synthesized Co3O4/rGO nanocomposites were determined by cyclic voltammetry and charge-discharge cycle to evaluate the supercapacitive performance. The specific capacitance of 754 Fg−1 was recorded for Co3O4/rGO nanocomposite based electrode in three electrode cell system. The electrode material exhibited an acceptable capability and excellent long-term cyclic stability by maintaining 96% after 1000 continuous cycles. These results showed that the prepared sample could be an ideal candidate for high-energy application as electrode materials. The synthesized Co3O4/rGO nanocomposite is a versatile material and can be used in various application such as fuel cells, electrochemical sensors, gas sensors, solar cells, and photocatalysis. © 2019 Elsevier Inc
Palliative and end-of-life care’s barriers for older adults
No full textPurpose: A nursing home is a place that is familiar with death, since many older adults will spend the latter part of their lives in such a setting. However, research on this topic is still limited, especially in Indonesia. The purpose of this paper is to explore the barriers to successful palliative and, more generally, end-of-life care (EOLC) for older adults in nursing homes and to explore nurses’ views on the subject. Design/methodology/approach: The study is of a qualitative nature and it employs a phenomenological approach. In-depth interviews with 15 nurses who taken care of older adults in a nursing home were conducted. The data were analysed using thematic content analysis. Findings: Barriers to effective EOLC include lack of knowledge, ineffectual communication and insufficient resources. Research limitations/implications: Better policies are needed, especially in training related to palliative/EOLC subjects and equitable distribution of professional health workers to overcome the barriers. The government should also encourage collaboration involving hospitals, Puskesmas (Health Centre Services), community and resident care settings in sharing knowledge and skills, especially for nurses. Originality/value: The barriers identified in palliative and EOLC have been found to be almost identical to those encountered in other health services. © 2019, Emerald Publishing Limited
Safety climate factors at selected chemical manufacturing plant in Malaysia
No full textStatistics in Malaysia show accident cases in the manufacturing industry is the highest as compared to another sector. The concept of safety climate gained interest in many industries as a means of reducing accident. This study assessed workers' perceptions toward safety climate factors, management commitment, communication, a priority of safety, safety rules procedures, social environment, supportive environment, involvement, personal priorities and need for safety, personal appreciation of risk, physical work environment, and lastly top management's commitment and priority. Safety Climate Assessment Toolkit and Zohar Safety Climate Questionnaires were used in this study. A cross-sectional sample of 309 workers participated. Lowest total mean score was for a personal appreciation of risk (M = 5.41, SD = 1.03), supportive environment (M = 6.61, SD = 0.82), and physical work environment (M = 6.74, SD = 1.24). There was a significant difference between production and nonproduction workers for their perceptions toward involvement in safety (Z = 15.579, P <.001). From the correlation test, age, gender, education level, shift work, and the group were significantly correlated with the nine dimensions of safety climate. Lastly, workers' perception of how management prioritized safety is generally good. A total mean score is (4.89) from the 16 items of Zohar safety climate questionnaire which covers declarative, proactive, and active practices of their management. © 2019 American Institute of Chemical Engineer
Macroline, talpinine, and sarpagine alkaloids from Alstonia penangiana. An NMR-based method for differentiating between A. penangiana and A. macrophylla
No full textFourteen previously undescribed alkaloids comprising two N-1-hydroxymethylmacroline alkaloids, one talpinine-type oxindole acetal, a pair of equilibrating talpinine-type oxindole hemiacetals, eight oxidized derivatives of sarpagine- and akuammiline-type indole alkaloids, in addition to alstochalotine a diastereomer of gelsochalotine recently isolated from Gelsemium elegans, were isolated from the leaf and stem-bark extracts of Alstonia penangiana. The structures and relative configurations of these alkaloids were established using NMR, MS, and in one instance, confirmed by X-ray diffraction analysis. An NMR-based method is described as a useful chemotaxonomic tool for differentiating between A. penangiana and A. macrophylla. Several of the alkaloids isolated showed appreciable growth inhibitory effects when tested against a number of human cancer cell lines. © 2020 Elsevier Lt
Bundled plastic optical fiber based sensor for ECG signal detection
No full textThis study demonstrates the development of a novel low-cost bundled plastic optical fiber (POF) displacement sensor for the measurement of amplitude and frequency of heart rate signal. A compact optical setup is developed in the laboratory for use in the testing. It consists of a fiber optic transmitter, fiber optic bundled probe and photodiode detector, and an electrocardiogram (ECG) simulator as a heart rate signal. The sensitivity of the sensor is found to be 4.6 mV/mm, and thus it is capable of measuring heart rate from 30 bpm to 300 bpm (for the amplitude of ECG at 0.5, 1.0 and 2.0 mV) with linearity of more than 99 %.The results demonstrate that the proposed fiber optic based heart rate sensor is not only easy-to-make, cost-effective and robust but also offers sensitive, stable and high precision heart beat measurements. © 2019 Elsevier Gmb
Cancer Risks Associated With Germline PALB2 Pathogenic Variants: An International Study of 524 Families
No full textPURPOSE To estimate age-specific relative and absolute cancer risks of breast cancer and to estimate risks of ovarian, pancreatic, male breast, prostate, and colorectal cancers associated with germline PALB2 pathogenic variants (PVs) because these risks have not been extensively characterized. METHODS We analyzed data from 524 families with PALB2 PVs from 21 countries. Complex segregation analysis was used to estimate relative risks (RRs; relative to country-specific population incidences) and absolute risks of cancers. The models allowed for residual familial aggregation of breast and ovarian cancer and were adjusted for the family-specific ascertainment schemes. RESULTS We found associations between PALB2 PVs and risk of female breast cancer (RR, 7.18; 95% CI, 5.82 to 8.85; P = 6.5 × 10-76), ovarian cancer (RR, 2.91; 95% CI, 1.40 to 6.04; P = 4.1 × 10-3), pancreatic cancer (RR, 2.37; 95% CI, 1.24 to 4.50; P = 8.7 × 10-3), and male breast cancer (RR, 7.34; 95% CI, 1.28 to 42.18; P = 2.6 3 1022). There was no evidence for increased risks of prostate or colorectal cancer. The breast cancer RRs declined with age (P for trend = 2.0 × 10-3). After adjusting for family ascertainment, breast cancer risk estimates on the basis of multiple case families were similar to the estimates from families ascertained through population-based studies (P for difference = .41). On the basis of the combined data, the estimated risks to age 80 years were 53% (95% CI, 44% to 63%) for female breast cancer, 5% (95% CI, 2% to 10%) for ovarian cancer, 2%-3% (95% CI females, 1% to 4%; 95% CI males, 2% to 5%) for pancreatic cancer, and 1% (95% CI, 0.2% to 5%) for male breast cancer. CONCLUSION These results confirm PALB2 as a major breast cancer susceptibility gene and establish substantial associations between germline PALB2 PVs and ovarian, pancreatic, and male breast cancers. These findings will facilitate incorporation of PALB2 into risk prediction models and optimize the clinical cancer risk management of PALB2 PV carriers. © 2019 by American Society of Clinical Oncology
The Economic Burden of Candidemia and Invasive Candidiasis: A Systematic Review
No full textBackground: Candidemia or invasive candidiasis (IC) is an increasingly common fungal infection and has been associated with high mortality, particularly among the immunocompromised and critically ill. Although several studies have been conducted to estimate the cost of managing candidemia and IC, quality assessment on the methodological aspects of these cost studies was not performed. To date, no systematic review focusing on the economic burden of candidemia and IC has ever been conducted. Objectives: The aim of this study was to systematically review the available evidence on the economic burden of candidemia and IC worldwide. Methods: Databases (ie, PubMed, Scopus, EconLit, HEORO, and Ovid/Embase) were searched through June 2018. Two researchers independently assessed the quality of the eligible studies. Costs reported in the included studies were converted to 2016 USD using Campbell and Cochrane Economics Methods Group-the Evidence for Policy and Practice Information (CCEMG–EPPI)-Centre Cost Converter software. Results: Eight articles were included in this systematic review. The mean total cost per patient with candidemia and IC ranged from 157 574, whereas the mean cost per hospitalization associated with candidemia and IC was from 37 715. All studies were from developed Western countries and reported only direct costs of candidemia and IC. Hospitalization was the main cost driver, contributing to more than half of the total costs. Conclusion: Quality cost studies on candidemia and IC based on standardized methods to provide informed decision making among healthcare authorities in implementing appropriate strategies is anticipated, in particular in developing countries. © 2019 ISPOR--The professional society for health economics and outcomes researc
A 350 mV, 280 μW 1.5-to-4.5-GHz wideband folded mixer adopting capacitive-cross-plus-magnetic-coupling
No full textThis paper describes a 1.5–4.5 GHz CMOS wideband mixer that operates from a single supply of 350 mV, allowing direct powering from various energy harvesting sources. The key techniques adopted for low power and low voltage operation are: (1) complementary transconductance stage in folded topology and current reuse, (2) forward body bias, and (3) gm-boosting by capacitor-cross and transformer coupled (CCTC). The CCTC achieves a high conversion gain (Gc) and a wideband input impedance matching under low power operation. Designed in 130-nm CMOS process, the mixer exhibits Gc of 12.2–16.4 dB and noise figure (NF) of 8.2–12 dB. The maximum input-referred 3rd-order intercept point (IIP3) is −11 dBm while consuming only 280 μW of power at an intermediate frequency (IF) of 50 MHz. The low power and low supply operation render the proposed CMOS mixer suitable for communication among multiple sensor nodes in a wireless body-area sensor network (WBAN). © 202
Heavy metals (Cr, Pb, Cd, Ni) in aerosols emitted from electronic cigarettes sold in Malaysia
No full textWhile past studies have detected heavy metals in aerosols emitted from electronic cigarettes (ECIG), they have provided little information detailing the practical implications of the findings to the Malaysian population due to variations between products. The aims of this study were to analyse heavy metals of interest (HMOI) in the aerosols emitted from selected ECIG and to evaluate potential health risks by referring to the permissible daily exposure (PDE) from inhalational medications defined by the United States Pharmacopeia Chapter 232. All four HMOI were detected in aerosols emitted from the selected ECIG in Sarawak. Among the four, Cr was present at the highest median levels (6.86 ng/m3), followed by Ni (0.30 ng/m3), Pb (0.19 ng/m3) and Cd (0.01 ng/m3). Five out of 100 combinations (5%) of ECIG and ECIG liquids were found to emit Cr that exceed the recommended PDE. Future studies examining more heavy metal variants, using a larger sample size and different analytical techniques to compare various ECIGs are recommended. © 2019, © 2019 Taylor & Francis Group, LLC
Improving artificial intelligence models accuracy for monthly streamflow forecasting using grey Wolf optimization (GWO) algorithm
No full textMonthly streamflow forecasting is required for short- and long-term water resources management especially in extreme events such as flood and drought. Therefore, there is need to develop a reliable and precise model for streamflow forecasting. The precision of Artificial Intelligence (AI) models can be improved by using hybrid AI models which consist of coupled models. Therefore, the chief aim of this study is to propose efficient hybrid system by integrating Grey Wolf Optimization (GWO) algorithm with Artificial Intelligence (AI) models. 130 years of monthly historical natural streamflow data will be used to evaluate the performance of the proposed modelling technique. Quantitative performance indicators will be introduced to evaluate the validity of the integrated models; in addition to that, comprehensive analysis will be conducted between the predicted and the observed streamflow. The results show the integrated AI with GWO outperform the standard AI methods and can make better forecasting during training and testing phases for the monthly inflow in all input cases. This finding reveals the superiority of GWO meta-heuristic algorithm in improving the accuracy of the standard AI in forecasting the monthly inflow. © 2019 Elsevier B.V