19672 research outputs found
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Mixed-ligand copper(II) complex of quercetin regulate osteogenesis and angiogenesis
No full textCopper(II) complex of quercetin Cu + Q, mixed ligand complexes, quercetin-Cu(II)-phenanthroline [Cu + Q(PHt)] and quercetin-Cu(II)-neocuproine [Cu + Q(Neo)] have been synthesized and characterized. From the FT-IR spectroscopic studies, it was evident that C-ring of quercetin is involved in the metal chelation in all the three copper complexes. C-ring chelation was further proven by UV–Visible spectra and the presence of Cu(II) from EPR spectroscopic investigations. These complexes were found to have osteogenic and angiogenic properties, observed through in vitro osteoblast differentiation and chick embryo angiogenesis assay. In osteoblast differentiation, quercetin-Cu(II) complexes treatment increased calcium deposition and alkaline phosphatase activity (ALP) activity at the cellular level and stimulated Runx2 mRNA and protein, ALP mRNA and type 1 collagen mRNA expression at the molecular level. Among the complexes, Q + Cu(PHt) showed more effects on osteoblast differentiation when compared to that of other two copper complexes. Additionally, Q + Cu(Neo) showed more effect compared to Q + Cu. Furthermore, the effect of these complexes on osteoblast differentiation was confirmed by the expression of osteoblast specific microRNA, pre-mir-15b. The chick embryo angiogenesis assay showed that angiogenic parameters such as blood vessel length, size and junctions were stimulated by these complexes. Thus, the present study demonstrated that quercetin copper(II) complexes exhibit as a pharmacological agent for the orthopedic application
Trends and variations in the prescribing of secondary preventative cardiovascular therapies for non-ST elevation myocardial infarction (NSTEMI) in Malaysia
No full textPurpose: Information is lacking on prescribing of preventative cardiovascular pharmacotherapies for patients with non-ST elevation myocardial infarction (NSTEMI) in the Asian region. This study examined the prescribing rate of these pharmacotherapies, comparing NSTEMI to STEMI, and variations across demographics and clinical factors within the NSTEMI group in the multi-ethnic Malaysian population. Methods: This is a retrospective analysis of the Malaysian National Cardiovascular Disease Database-Acute Coronary Syndrome registry from year 2006 to 2013 (n = 30,873). On-discharge pharmacotherapies examined were aspirin, ADP-antagonists, statins, ACE-inhibitors, angiotensin-II-receptor blockers, and beta-blockers. Multivariate logistic regression was used to calculate adjusted odds ratio of receiving individual pharmacotherapies according to patients’ characteristics in NSTEMI patients (n = 11,390). Results: Prescribing rates for cardiovascular pharmacotherapies had significantly increased especially for ADP-antagonists (76%) in NSTEMI patients. More than 85% were prescribed statins and antiplatelets but rates remained significantly lower compared to STEMI. Women and those over 65 years old were less likely to be prescribed these pharmacotherapies compared to men and younger NSTEMI patients. Chinese and Indians were more likely to receive selected pharmacotherapies compared to Malays (main ethnicity). Geographical variations were observed; East Malaysian (Malaysian Borneo) patients were less likely to receive these compared to Western region of Malaysian Peninsular. Underprescribing in patients with risk factors such as diabetes were observed with other co-morbidities influencing prescribing selectively. Conclusion: This study uncovers demographic and clinical variations in cardiovascular pharmacotherapies prescribing for NSTEMI. Concerted efforts by policy makers, specialty societies, and physicians are required focusing on elderly, women, Malays, East Malaysians, and high-risk patients
Palm oil intensification and expansion in Indonesia and Malaysia: Environmental and socio-political factors influencing policy
No full textIntensification and expansion are two essential tenets of commercial agriculture. This paper analyses trends of intensification and expansion at the national level, particularly in the oil palm sector in Indonesia and Malaysia. Despite similar starting points and also comparable rates of increasing productivity and profit in this sector, both countries have developed almost opposite trajectories of land use. While both intensification and expansion has occurred in these countries, national indicators show that Malaysia has largely pursued intensification while Indonesia has overwhelmingly favoured expansion. Using the framework of the Jevons paradox, this paper contributes to the existing literature by arguing how and why political and social factors, rather than technology and market incentives, can better account for the differences between yield and land use efficiency in Indonesia and Malaysia today. The paper argues that expansion in Malaysia has been curtailed by the Malaysian government's pledge to maintain at least 50% forest cover in the late 1990s, coupled with a government supported corporate strategy of establishing plantations in Indonesia. Indonesia has made no such pledge, leading to expansionist policies focused on market creation and production goals with limited incentives for technology-driven intensification. It also notes however that in recent years, new socio-political developments in both countries may yet change this clear dichotomy of opposing land use strategies between these two countries, namely Sarawak's recent autonomous tendencies over land use and Indonesia's new leadership and international No Deforestation Peat and Exploitation (NDPE) commitments
The visible reflectance spectrum stability and water content resistivity of natural dye coating paint film consisting chlorophyll
No full textPurpose: The purpose of this paper is to study the colour stability and water content resistivity of the green colour coating paint film (consisting of chlorophyll) during exposure to ultraviolet A (UV-A). Design/methodology/approach: The natural green dye was prepared by immersing Cassia alata L. leaves in absolute ethanol. The extract was prepared in two batches of dye samples where one of it was a pure dye and the other was added with 3 Wt. % Cu(NO3)2 as an additive. Polymer blend as a binder was prepared by mixing poly(methyl methacrylate) (PMMA) and commercial acrylic polyol. The blended polymer was mixed with the natural dye in a specific ratio and applied as coating paint film on glass panel surfaces. The visible spectrum stability (colour stability) and water content resistivity of the coating paint films during exposure to UV-A were monitored. Findings: Addition of Cu(NO3)2 had improved the colour stability of the coating paint film. Fourier transform infrared spectroscopy analysis showed that both coating paint films do not absorb water and are resistive to water content. Research limitations/implications: The ability of Cu(NO3)2 as an colour stability additive to the natural green dye applied in the coating paint film. Practical implications: The coating paint film developed in this work is suitable to be applied on glass substrates. Originality/value: The colour stability of the coating paint film was analysed by using the reflectance spectrum
Nanocrystalline cellulose from agricultural waste: an overview
No full textCellulose is a very widely available biomass found in nature. Cellulose can be isolated from regular filaments; its dynamic and structural association enables various types of nanostructured celluloses called nanocrystalline cellulose or microstructure cellulose. More recently, literature survey reveals that cellulose nanoparticles have been separated and utilised for a few applications in various fields. Thus, there is a growing interest among the scientific research community to understand nanocrystalline cellulose and tap it for its usage in diverse scientific fields. The vast majority of the examinations in the course of the most recent couple of years have demonstrated that nanocrystalline cellulose can be utilised as filler materials to improve the mechanical and barrier properties of biocomposites. Their importance of nanocrystalline to enhance the mechanical properties is being investigated; with extensive research being focussed to discover inventive answers for effective and manageable frame works. This paper plans to give an unmistakable outline of nanocrystalline cellulose of 44 references by depicting their readiness, portrayal, behaviour, importance and applications
Molecular Genetic Characterization of Patients With Focal Epilepsy Using a Customized Targeted Resequencing Gene Panel
No full textObjective: Focal epilepsy is the most common subtype of epilepsies in which the influence of underlying genetic factors is emerging but remains largely uncharacterized. The purpose of this study is to determine the contribution of currently known disease-causing genes in a large cohort (n = 593) of common focal non-lesional epilepsy patients. Methods: The customized focal epilepsy gene panel (21 genes) was based on multiplex polymerase chain reaction (PCR) and sequenced by Illumina MiSeq platform. Results: Eleven variants (1.85%) were considered as pathogenic or likely pathogenic, including seven novel mutations. There were three SCN1A (p.Leu890Pro, p.Arg1636Ter, and p.Met1714Val), three PRRT2 (two p.Arg217Profs*8 and p.Leu298Pro), two CHRNA4 (p.Ser284Leu, p.Ile321Asn), one DEPDC5 (p.Val516Ter), one PCDH19 (p.Asp233Asn), and one SLC2A1 (p.Ser414Ter) variants. Additionally, 16 other rare variants were classified as unknown significance due to inconsistent phenotype or lack of segregation data. Conclusion: Currently known focal epilepsy genes only explained a very small subset of focal epilepsy patients. This indicates that the underlying genetic architecture of focal epilepsies is very heterogeneous and more novel genes are likely to be discovered. Our study highlights the usefulness, challenges and limitations of using the multi-gene panel as a diagnostic test in routine clinical practice in patients with focal epilepsy
Production and Characterization of a Bioflocculant Produced by Bacillus salmalaya 139SI-7 and Its Applications in Wastewater Treatment
No full textThe production, optimization, and characterization of the bioflocculant QZ-7 synthesized by a novel Bacillus salmalaya strain 139SI isolated from a private farm soil in Selangor,Malaysia, are reported. The flocculating activity of bioflocculant QZ-7 present in the selected strain was found to be 83.3%. The optimal culture for flocculant production was achieved after cultivation at 35.5 °C for 72 h at pH 7 ± 0.2, with an inoculum size of 5% (v/v) and sucrose and yeast extract as carbon and nitrogen sources. The maximum flocculating activity was found to be 92.6%. Chemical analysis revealed that the pure bioflocculant consisted of 79.08% carbohydrates and 15.4% proteins. The average molecular weight of the bioflocculant was calculated to be 5.13 × 105 Da. Infrared spectrometric analysis showed the presence of carboxyl (COO-), hydroxyl (-OH), and amino (-NH2) groups, polysaccharides and proteins. The bioflocculant QZ-7 exhibited a wide pH stability range from 4 to 7, with a flocculation activity of 85% at pH 7 ± 0.2. In addition, QZ-7 was thermally stable and retained more than 80% of its flocculating activity after being heated at 80 °C for 30 min. SEM analysis revealed that QZ-7 exhibited a clear crystalline brick-shaped structure. After treating wastewater, the bioflocculant QZ-7 showed significant flocculation performance with a COD removal efficiency of 93%, whereas a BOD removal efficiency of 92.4% was observed in the B. salmalaya strain 139SI. These values indicate the promising applications of the bioflocculant QZ-7 in wastewater treatment
Integrating fuzzy expert system and scoring system for safety performance evaluation of offshore oil and gas platforms in Malaysia
No full textThis study proposes an integrative safety performance evaluation framework using both scoring and fuzzy expert systems for offshore oil and gas platforms in Malaysia. Fourteen safety factors are used as the basis of performance evaluation. To generate the safety score of each safety factor, weights of the indicators grouped under the safety factor are first multiplied with the compliance levels assigned to the respective indicators. The products of weights and compliance levels are then summed up, yielding the safety score. The scores of safety factors serve as inputs of the fuzzy expert system to determine the overall safety performance of an offshore oil and gas platform. The scoring and fuzzy expert systems are tested on ten offshore oil platforms in Malaysia. All the platforms tested meet the status of ‘compliant’ defined by the rules of the expert system. The crisp outputs correspond well with the total safety scores of the platforms. However, irregularities are observed in the crisp outputs when tested with various compliance scenarios, indicating that rules set by the experts have larger effect on the outputs than the total safety scores obtained. All scenarios of membership function used for the inputs and outputs do not demonstrate significant difference in the R-squared values obtained from the plots of total safety scores against crisp outputs. This study contributes to identification of the most appropriate set-up of fuzzy expert system which can be integrated with this framework to permit integrative safety performance evaluation for early warning provision and performance benchmarking. This paper presents a novel use of fuzzy expert system in safety performance measurement of offshore platforms which contributes significantly to the management and retention of experts’ knowledge in decision-making pertaining to safety performance
New insights into the photocatalytic endocrine disruptors dimethyl phathalate esters degradation by UV/MWCNTs-TiO2 nanocomposites
No full textDimethyl phthalate esters (DMPEs) are considered to be endocrine disruptors and environmentally hazardous materials in plastic industries wastewater because of its low solubility and accumulated persistent toxicity. In the present study, MWCNTs/TiO2 nanocomposites were fabricated by modified sol-gel technique using titanium isopropoxide as titanium oxide sources and purified MWCNTs, to degrade DMPEs through photocatalysis using UV irradiation. The effect of MWCNTs loading (3–15 wt %) on TiO2 and the photocatalytic performance of DMPEs in aqueous solution by UV/MWCNTs/TiO2 nanocomposites were investigated. For experiments conducted with the same illumination time, the photodegradration of DMPEs was enhanced with increasing the MWCNTs contents from 3 to 10 wt % and then decreased with a further enhancement to 15 wt %. Basically, the presence of MWCNTs in the nanocomposites can lead to the decrease in the relative amount of TiO2 in the photocatalyst and then to the decrease of the photogenerated carriers. This is because the same amount of photocatalyst was added for the photoreaction, and hence, the photodegradation of DMPEs decreases especially for the nanocomposites containing MWCNTs exceed than 10 wt %. The presence of functional group (–COOH) on the MWCNTs surface would help the achievement of direct chemical bonding between MWCNTs and the TiO2 nanoparticles, resulting in the synergistic effect of MWCNTs and TiO2 where the flow of photogenerated electrons in the space charge region to the MWCNTs surface. A method based on high-performance liquid chromatography (HPLC) was developed to study the degraded DMPEs samples produced after exposure to UV light
Design technique for leakage current reduction in surge arrester using gravitational search algorithm and imperialist competitive algorithm
No full textPurpose - Leakage current is one of the factors, which can contribute towards degradation of surge arresters. Thus, the purpose of this paper is to study on leakage current within surge arresters and improvement on their design. Design/methodology/approach - In this work, a three-dimensional model geometry of 11 kV zinc oxide surge arrester was designed in finite element analysis and was applied to calculate the leakage current under normal operating condition and being verified with measurement results. The optimisationmethods were used to improve the arrester design by minimising the leakage current across the arrester using imperialist competitive algorithm (ICA) and gravitational search algorithm(GSA). Findings - The arrester design in reducing leakage current was successfully optimised by varying the glass permittivity, silicone rubber permittivity and the width of the ground terminal of the surge arrester. It was found that the surge arrester design obtained using ICA has lower leakage current than GSA and the original design of the surge arrester. Practical implications - The comparison between measurement and simulation enables factors that affect themechanism of leakage current in surge arresters to be identified and provides the ideal design of arrester. Originality/value - Surge arrester design was optimised by ICA and GSA, which has never been applied in past works in designing surge arrester with minimumleakage current