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CoCl2-doped polyaniline composites as electrode materials with enhanced electrochemical performance for supercapacitor application
No full textHCl-doped polyaniline (PANI) and polymeric composites of polyaniline– cobalt chloride (PANI–CoCl2) were synthesized in the laboratory via an in situ oxidative polymerization technique. Their chemical, structural and morphological properties were examined through FESEM, XRD, EDX and FTIR spectroscopic techniques. The electrochemical performance of the as-prepared composites was examined through cyclic voltammogram, electrochemical impedance spectroscopy and galvanostatic charge/discharge measurement techniques. The thermal properties of the as-prepared composites were examined through thermal gravimetric analysis technique. The results obtained were found satisfactory and well suitable for its use as hybrid electrode materials for supercapacitor application
Shadow education: patterns and scale of private supplementary tutoring in English in secondary education at urban Dhaka in Bangladesh
No full textPrivate supplementary tutoring with an additional fee is generally called shadow education, and this has become a common phenomenon in urban Dhaka, where patterns and scale of tutoring in English have been remarkable in recent years. This study used a mixed-methods approach that included quantitative and qualitative data collected from a survey and individual interview. Tutoring in English has been a regular feature of the teaching profession in this urban area. The paper examines various patterns of private tutoring in English and focuses on the amount of tutoring, including the tutoring received and not received by students in urban Dhaka. It shows the variations of scale regarding tutoring in English between male and female students. The study also identifies different types of private tutors who deliver supplementary tutoring. Finally, the choices pupils make regarding their evaluation on the effectiveness of shapes of tutoring in English are discussed
Preparation of Poly (dl-Lactide-co-Glycolide) Nanoparticles Encapsulated with Periglaucine A and Betulinic Acid for In Vitro Anti-Acanthamoeba and Cytotoxicity Activities
No full textPoly (DL-lactide-co-glycolide) (PLGA) microspheres were synthesized as delivery system for the natural anti-parasitic compounds, Periglaucine A (PGA) and Betulinic acid (BA). Periglaucine A and Betulinic acid were encapsulated in PLGA nanoparticles by single emulsion method with an average particle size of approximately 100–500 nm. Periglaucine A and Betulinic acid encapsulation efficiency was observed to be 90% and 35% respectively. Anti-Acanthamoeba property of Periglaucine A and Betulinic acid remained intact after encapsulation. PGA-PLGA and BA-PLGA nanoparticles demonstrated inhibition in viability of Acanthamoeba triangularis trophozoites by 74.9%, 59.9%, 49.9% and 71.2%, 52.2%, 88% respectively at concentration of 100 µg/mL, 50 µg/mL and 25 µg/mL. Cytotoxicity of PGA-PLGA and BA-PLGA nanoparticles has been evaluated against lung epithelial cell line and showed dose dependent cytotoxicity value of IC50 2 µg/mL and 20 µg/mL respectively. Futher, increased viability was observed in lung epithelial cell line in higher doses of synthesized polymeric nanoparticles. Results indicate that poly (DL-lactide-co-glycolide) (PLGA) nanoparticles could be exploratory delivery systems for natural products to improve their therapeutic efficacy
Optimum Oil Palm Shell Content as Coarse Aggregate in Concrete Based on Mechanical and Durability Properties
No full textOil palm shell (OPS) is a biosolid waste in palm oil industry in the tropical countries which could be used as aggregate in concrete mixture. Since 1984, OPS has been experimented as natural lightweight aggregate in research studies to produce lightweight concrete (LWC). Medium and high-strength LWCs using OPS as coarse aggregate were successfully produced. However, higher drying shrinkage and lower mechanical properties for concretes containing higher volume of OPS are reported in previous studies. Therefore, OPS is not fit to be used as full coarse aggregate in concrete mixture and therefore, there should be an optimum OPS content in concrete. In this study, in a normal-weight concrete, normal coarse aggregate was replaced with OPS from zero to 100% with an interval of 20%. Tests such as slump, density, compressive strength in different curing conditions, splitting tensile strength, initial and final water absorptions, and drying shrinkage of cured and uncured specimens were conducted to find out optimum OPS content in concrete. From the test results, it could be summarized that OPS content should not exceed 60% of total volume of coarse aggregate
Inelastic responses of swollen nitrile rubber under cyclic loading
No full textPalm biodiesel is deemed a promising future fuel substitute for conventional diesel fuel. In line with this perspective, necessary changes in the existing diesel engine system are expected in order to address the issue of material compatibility. One typical degradation observed in rubber components exposed to aggressive solvent such as palm biodiesel during the service is swelling. Thus, the investigation of the effect of swelling on the mechanical response under cyclic loading is prerequisite for durability analysis of such components. In this study, filled and unfilled swollen nitrile rubbers are immersed in conventional diesel and palm biodiesel baths until a 5% swelling level is achieved. Both dry and swollen rubbers are subjected to uniaxial cyclic loading tests. The analysis of the mechanical responses has shown that swelling decreases inelastic effects such as hysteresis, stress softening, and permanent set. For both dry and swollen rubbers, fillers are found to have significant effects in the inelastic responses, whereas the effects of solvent and loading rate are comparable
Association between night-shift work, sleep quality and metabolic syndrome
No full textObjectives Occupational factors, particularly night-shift work, are attracting growing interest as a possible determinant of metabolic syndrome (MetS). This study aimed to determine the association between night-shift work and MetS, and assess whether sleep quality is a mediating factor. Methods A cross-sectional study was conducted among Malaysian manufacturing workers, aged 40-65 years old. They completed a self-administered questionnaire on sociodemographics, lifestyle and family history, and the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Waist circumference, blood pressure, fasting blood sugar, triglycerides and high-density lipoprotein levels were measured. Baron and Kenny's method, Sobel test and multiple mediation models with bootstrapping were used to determine whether the PSQI global score or its components mediated the association between night-shift work and MetS. Results Of the 494 participants, 177 (36%) worked night shift and 51% were men. The prevalence of MetS was 37%. Night-shift work was independently associated with a twofold increase in the risk of MetS (adjusted OR: 1.92, 95% CI 1.24 to 2.97). However, the association between night-shift work and MetS did not appear to be modified by sex. Night-shift workers also reported significantly poorer sleep quality, longer sleep latency, shorter sleep duration, sleep disturbances and daytime dysfunction. Robust mediation analysis nonetheless showed that neither PSQI global score nor its components mediated the association between night-shift work and MetS. Conclusion Early screening and management of MetS and the development of programmes to improve sleep quality should be carried out among night-shift workers. Future research should investigate other modifiable mediators linking night-shift work and MetS
Adaptive template matching of photoplethysmogram pulses to detect motion artefact
No full textObjective: The photoplethysmography (PPG) signal, commonly used in the healthcare settings, is easily affected by movement artefact leading to errors in the extracted heart rate and SpO 2 estimates. This study aims to develop an online artefact detection system based on adaptive (dynamic) template matching, suitable for continuous PPG monitoring during daily living activities or in the intensive care units (ICUs). Approach: Several master templates are initially generated by applying principal component analysis to data obtained from the PhysioNet MIMIC II database. The master template is then updated with each incoming clean PPG pulse. The correlation coefficient is used to classify the PPG pulse into either good or bad quality categories. The performance of our algorithm was evaluated using data obtained from two different sources: (i) our own data collected from 19 healthy subjects using the wearable Sotera Visi Mobile system (Sotera Wireless Inc.) as they performed various movement types; and (ii) ICU data provided by the PhysioNet MIMIC II database. The developed algorithm was evaluated against a manually annotated 'gold standard' (GS). Main results: Our algorithm achieved an overall accuracy of 91.5% ± 2.9%, with a sensitivity of 94.1% ± 2.7% and a specificity of 89.7% ± 5.1%, when tested on our own data. When applying the algorithm to data from the PhysioNet MIMIC II database, it achieved an accuracy of 98.0%, with a sensitivity and specificity of 99.0% and 96.1%, respectively. Significance: The proposed method is simple and robust against individual variations in the PPG characteristics, thus making it suitable for a diverse range of datasets. Integration of the proposed artefact detection technique into remote monitoring devices could enhance reliability of the PPG-derived physiological parameters
A novel language-neutral Visual Cognitive Assessment Test (VCAT): validation in four Southeast Asian countries
No full textBackground: Cognitive screeners are imperative for early diagnosis of dementia. The Visual Cognitive Assessment Test (VCAT) is a language-neutral, visual-based test which has proven useful for a multilingual population in a single-center study. However, its performance utility is unknown in a wider and more diverse Southeast Asian cohort. Methods: We recruited 164 healthy controls (HC) and 120 cognitively impaired (CI) subjects- 47 mild cognitive impairment (MCI) and 73 mild Alzheimer's disease (AD) dementia participants, from four countries between January 2015 and August 2016 to determine the usefulness of a single version of the VCAT, without translation or adaptation, in a multinational, multilingual population. The VCAT was administered along with established cognitive evaluation. Results: The VCAT, without local translation or adaptation, was effective in discriminating between HC and CI subjects (MCI and mild AD dementia). Mean (SD) VCAT scores for HC and CI subjects were 22.48 (3.50) and 14.17 (5.05) respectively. Areas under the curve for Montreal Cognitive Assessment (0.916, 95% CI 0.884-0.948) and the VCAT (0.905, 95% CI 0.870-0.940) in discriminating between HCs and CIs were comparable. The multiple languages used to administer VCAT in four countries did not significantly influence test scores. Conclusions: The VCAT without the need for language translation or cultural adaptation showed satisfactory discriminative ability and was effective in a multinational, multilingual Southeast Asian population
Is BRCA Mutation Testing Cost Effective for Early Stage Breast Cancer Patients Compared to Routine Clinical Surveillance? The Case of an Upper Middle-Income Country in Asia
No full textObjective: Previous studies showed that offering BRCA mutation testing to population subgroups at high risk of harbouring the mutation may be cost effective, yet no evidence is available for low- or middle-income countries (LMIC) and in Asia. We estimated the cost effectiveness of BRCA mutation testing in early-stage breast cancer patients with high pre-test probability of harbouring the mutation in Malaysia, an LMIC in Asia. Methods: We developed a decision analytic model to estimate the lifetime costs and quality-adjusted life-years (QALYs) accrued through BRCA mutation testing or routine clinical surveillance (RCS) for a hypothetical cohort of 1000 early-stage breast cancer patients aged 40 years. In the model, patients would decide whether to accept testing and to undertake risk-reducing mastectomy, oophorectomy, tamoxifen, combinations or neither. We calculated the incremental cost-effectiveness ratio (ICER) from the health system perspective. A series of sensitivity analyses were performed. Results: In the base case, testing generated 11.2 QALYs over the lifetime and cost US4574 per patient. The ICER of US9500/QALY, 99.9% of simulations favoured BRCA mutation testing over RCS. Conclusions: Offering BRCA mutation testing to early-stage breast cancer patients identified using a locally-validated risk-assessment tool may be cost effective compared to RCS in Malaysia
Localizing English literature as a school subject: a Malaysian experience
No full textThis article explores some of the complexities involved in the act of localizing English literature as a school subject. Informed by Goodson and Marsh’s stages of subject development, I explore the ways in which post-16 English literature was localized in Malaysia from an introduced and mythologized subject entitled “English” to its reconceptualization as “Literature in English” in the year 1998. The main question this article asks is: can a mythologized subject be sustained when it is introduced into another context (i.e., Malaysia)? This question is explored through attempts made to localize it by the subject’s governing body in Malaysia, namely the Malaysian Examinations Council. Relevant documents as well as an interview with a subject committee member involved in the subject’s reconceptualization form the data of this article. Analysis suggests that not only were acts of localization incoherent in the subject’s implementation, the rationale for localization was also not shared by some constituencies within and beyond the education system. This article concludes by highlighting the importance of ensuring that support from relevant constituencies is based upon a shared understanding of a subject’s role, aims and conceptualization in order to sustain subject development in an education system