19672 research outputs found
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Mixed-methods approach to exploring patients’ perspectives on the acceptability of a urinary biomarker test in replacing cystoscopy for bladder cancer surveillance
No full textObjectives: To determine the minimal accepted sensitivity (MAS) of a urine biomarker that patients are willing to accept to replace cystoscopy and to assess qualitatively their views and reasons. Patients and Methods: Patients were part of a prospective multicentre observational study recruiting people with bladder cancer for a urine biomarker study (DETECT II; ClinicalTrials.gov: NCT02781428). A mixed-methods approach comprising (1) a questionnaire to assess patients’ experience with cystoscopy and patients’ preference for cystoscopy vs urinary biomarker, and (2) semi-structured interviews to understand patient views, choice and reasons for their preference. Results: A urine biomarker with an MAS of 90% would be accepted by 75.8% of patients. This was despite a high self-reported prevalence of haematuria (51.0%), dysuria/lower urinary tract symptoms (69.1%) and urinary tract infection requiring antibiotics (25.8%). There was no association between MAS with patient demographics, adverse events experienced, cancer characteristics or distance of patients’ home to hospital. The qualitative analysis suggested that patients acknowledge that cystoscopy is invasive, embarrassing and associated with adverse events but are willing to tolerate the procedure because of its high sensitivity. Patients have confidence in cystoscopy and appreciate the visual diagnosis of cancer. Both low- and high-risk patients would consider a biomarker with a reported sensitivity similar to that of cystoscopy. Conclusion: Patients value the high sensitivity of cystoscopy despite the reported discomfort and adverse events experienced after it. The sensitivity of a urinary biomarker must be close to cystoscopy to gain patients’ acceptance. © 2019 The Authors BJU International published by John Wiley & Sons Ltd on behalf of BJU Internationa
Process intensification of biodiesel synthesis via ultrasound-assisted in situ esterification of Jatropha oil seeds
No full textBACKGROUND: Non-edible oil such as Jatropha oil has high free fatty acids (FFAs) content. Therefore, acid esterification is a suitable route to reduce its FFA content to an acceptable limit (2 FFA%) before being subjected to further transesterification. In the present study, Jatropha seeds were utilized as the feedstock directly instead of Jatropha oil during ultrasound-assisted in situ esterification. The objective of this work is to evaluate the feasibility of in situ esterification of Jatropha oil seeds using sulphuric acid (H 2 SO 4 ) as catalyst with the aid of ultrasound. RESULTS: The reaction parameters (particle size, n-hexane to methanol volume ratio, H 2 SO 4 amount, reaction time and ultrasonic amplitude) were optimized and evaluated in term of extraction and esterification efficiencies as well as fatty acid methyl ester (FAME) yield. The highest extraction efficiency of 83.96%, esterification efficiency of 71.10% and FAME yield of 38.58% were achieved at particle size of 1–2 mm, n-hexane to methanol volume ratio of 3:1, 5 vol% of H 2 SO 4 and ultrasonic amplitude of 60% with reaction time of 150 min. CONCLUSION: Synthesis of biodiesel via ultrasound-assisted in situ esterification of Jatropha oil seeds was successful with considerable yield, which could provide improvement in terms of process intensification and more value added by-products. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industr
Streptomyces sp. MUM273b: A mangrove‐derived potential source for antioxidant and UVB radiation protectants
No full textMicrobial natural products serve as a good source for antioxidants. The mangrove-derived Streptomyces bacteria have been evidenced to produce antioxidative compounds. This study reports the isolation of Streptomyces sp. MUM273b from mangrove soil that may serve as a promising source of antioxidants and UV-protective agents. Identification and characterization methods determine that strain MUM273b belongs to the genus Streptomyces. The MUM273b extract exhibits antioxidant activities, including DPPH, ABTS, and superoxide radical scavenging activities and also metal-chelating activity. The MUM273b extract was also shown to inhibit the production of malondialdehyde in metal-induced lipid peroxidation. Strong correlation between the antioxidant activities and the total phenolic content of MUM273b extract was shown. In addition, MUM273b extract exhibited cytoprotective effect on the UVB-induced cell death in HaCaT keratinocytes. Gas chromatography–mass spectrometry analysis detected phenolics, pyrrole, pyrazine, ester, and cyclic dipeptides in MUM273b extract. In summary, Streptomyces MUM273b extract portrays an exciting avenue for future antioxidative drugs and cosmeceuticals development. © 2019 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd
Design of polyurethane fibers: Relation between the spinning technique and the resulting fiber topology
No full textProperties or characteristics of fibers are affected by their topology. In fact, these topologies are found to have significant impacts in the functionalities of many applications. Hence, in this study, the relations between the spinning techniques and the topology of the resulting fibers are studied with the aim to provide a guideline for future reference where fibers with certain topology can be fabricated to suit specific applications. For this purpose, polyurethane is chosen to be the raw material to fabricate the fibers due to its versatility to be applied in various fields. The surface morphology, structures, and alignments of the fibers are studied. It is found that the polymer solution properties largely influence the mechanisms in the spinning process and can significantly affect the topology of the fibers. For instance, viscous solutions enable the spinning of coiled and smooth fibers, whereas conductive solutions encourage the splaying of the solution jet which results in the spinning of straight fibers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47706. © 2019 Wiley Periodicals, Inc
Exploring the potency of integrating semi-batch operation into lipid yield performance of Chlamydomonas sp. Tai-03
No full textThird generation biofuels, also known as microalgal biofuels, are promising alternatives to fossil fuels. One attractive option is microalgal biodiesel as a replacement for diesel fuel. Chlamydomonas sp. Tai-03 was previously optimized for maximal lipid production for biodiesel generation, achieving biomass growth and productivity of 3.48 ± 0.04 g/L and 0.43 ± 0.01 g/L/d, with lipid content and productivity of 28.6 ± 1.41% and 124.1 ± 7.57 mg/L/d. In this study, further optimization using 5% CO2 concentration and semi-batch operation with 25% medium replacement ratio, enhanced the biomass growth and productivity to 4.15 ± 0.12 g/L and 1.23 ± 0.02 g/L/d, with lipid content and productivity of 19.4 ± 2.0% and 239.6 ± 24.8 mg/L/d. The major fatty acid methyl esters (FAMEs) were palmitic acid (C16:0), oleic acid (C18:1), and linoleic acid (C18:2). These short-chain FAMEs combined with high growth make Chlamydomonas sp. Tai-03 a suitable candidate for biodiesel synthesis. © 2019 Elsevier Lt
Optimal sizing and energy scheduling of isolated microgrid considering the battery lifetime degradation
No full textThe incessantly growing demand for electricity in today’s world claims an efficient and reliable system of energy supply. Distributed energy resources such as diesel generators, wind energy and solar energy can be combined within a microgrid to provide energy to the consumers in a sustainable manner. In order to ensure more reliable and economical energy supply, battery storage system is integrated within the microgrid. In this article, operating cost of isolated microgrid is reduced by economic scheduling considering the optimal size of the battery. However, deep discharge shortens the lifetime of battery operation. Therefore, the real time battery operation cost is modeled considering the depth of discharge at each time interval. Moreover, the proposed economic scheduling with battery sizing is optimized using firefly algorithm (FA). The efficacy of FA is compared with other metaheuristic techniques in terms of performance measurement indices, which are cost of electricity and loss of power supply probability. The results show that the proposed technique reduces the cost of microgrid and attain optimal size of the battery. © 2019 Sufyan 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
Association of Interleukin-10 Genotypes and Oral Cancer Susceptibility in Selected Malaysian Population: A Case- Control Study
No full textBackground: Interleukin-10 (IL10) genotypes have been closely correlated to the susceptibility for oral squamous cell carcinoma. More than half of oral cancers in the world occur in Asia with estimated 168,850 new cases were diagnosed in this geographical region alone. Considering the rising numbers of oral cancer cases in Malaysia, association of IL10 A1082G gene polymorphism was correlated. Methodology: 41 oral squamous cell carcinoma (OSCC) cases and 48 healthy controls of comparable age, gender, and with habits like smoking, alcohol consumption and betel quid chewing were selected. In this case-control study, samples were collected from the Oral Cancer Research and Coordinating Centre (OCRCC), Faculty of Dentistry, University of Malaya, Malaysia. Genotyping conditions were evaluated by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). The PCR products were subjected to digestion by MnlI enzyme (NEB, UK) to screen for the IL10 A-1082G. Digested DNA products were analyzed by electrophoresis on 4% (w/v) agarose gel, stained with ethidium bromide and imaged under UV illumination. Chi-square test and Fisher's Exact test were used in statistical analysis. Results: AG genotypes were present in 81.3% and 86.0% of healthy control and OSCC cases respectively (OR=0.468, 95% CI=0.133-1.653). No significant association was found between IL10 A1082G polymorphism with risk habits, clinico-pathological parameters and 5-years overall survival. The findings also show no significant correlation between the IL10 genotype and features of OSCC within the case group as measured by tumor size, lymph node involvement, stage, invasive front, grading, depth, pattern of invasion. Conclusion: This study suggests that functional polymorphism AG of IL10 A1082G may have no influence with OSCC susceptibility. However, further investigation with larger sample sizes can be conducted to provide additional evidence to support the lack of association of IL10 A1082G polymorphism in oral cancer. © 2019 IL10 Gene Polymorphism in Oral Cancer
Sociodemographic Characteristics as Determinants and Physical Performance Measures as Correlates of Falls Among Malaysian Community-Dwelling Older Adults
No full textThere is limited information regarding combined sociodemographic data and physical performance measures as determinants and correlates of falls among community-dwelling older adults. In this study, we aimed to identify whether sociodemographic data and physical performance measures are significant determinants and correlates for falls in community-dwelling older adults. Three hundred twenty-five Malaysian community-dwelling older adults (145 men and 180 women), aged 60 to 89 (M = 67.64, SD = 5.56) years, were recruited through multistage random samplings for this prospective study (with 6 months' follow-up). Binary logistic regression analysis was performed on the sociodemographic data and physical performance measures to determine the determinants and correlates of falls among these participants. The Physiological Profile Assessment (PPA) was the only significant (P <.05) physical performance measure that correlated with falls. The Timed Up and Go (TUG) Test and education levels were significant correlates and determinants of falls in this population, with the absence of PPA in the model. The PPA is the best physical performance measure correlate of falls among Malaysian community-dwelling older adults. However, when the PPA is not available, the TUG Test, although a simple performance tool, may be used to predict falls among community-dwelling older adults. © 2019 Wolters Kluwer Health, Inc. All rights reserved
Numerical Solution of Nonlinear Reaction–Advection–Diffusion Equation
No full textIn the present article, the advection-diffusion equation (ADE) having a nonlinear type source/sink term with initial and boundary conditions is solved using finite difference method (FDM). The solution of solute concentration is calculated numerically and also presented graphically for conservative and nonconservative cases. The emphasis is given for the stability analysis, which is an important aspect of the proposed mathematical model. The accuracy and efficiency of the proposed method are validated by comparing the results obtained with existing analytical solutions for a conservative system. The novelty of the article is to show the damping nature of the solution profile due to the presence of the nonlinear reaction term for different particular cases in less computational time by using the reliable and efficient finite difference method. © 2019 by ASME
The identification of outliers in wrapped normal data by using ga statistics
No full textThis paper focuses on identifying outliers in the wrapped normal distribution. It is commonly found and when it is dealing with circular data, the existing of outliers will increase several problems.We will be using the existing statistics, the G a statistics to identify a single and patch of outliers in the wrapped normal data. A Monte Carlo simulation will be carried out to generate the cut-off point’s value. The power performance of the discordancy test in circular data has been investigated. The increment of the contamination level, λ, large value of concentration parameter, ρ and large sample size, n will increase the performance of the outlier detection procedures. In addition, the result shows that the statistics performs well in detecting a patch of outliers in the data. As an illustration a practical example is presented by using the wind direction in Kota Bharu station. As conclusion, the G a statistics successfully detect outlier presence in this data set. © BEIESP