21 research outputs found

    Anti-malarial and anti-inflammatory effects of Gleichenia truncata mediated through inhibition of GSK3ß

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    Gleichenia truncata is a highland fern from the Gleicheniaceae family known for its traditional use among indigenous communities in Asia to treat fever. The scientific basis of its effect has yet to be documented. A yeast-based kinase assay conducted in our laboratory revealed that crude methanolic extract (CME) of G. truncata exhibited glycogen synthase kinase-3 (GSK3)-inhibitory activity. GSK3β is now recognized to have a pivotal role in the regulation of inflammatory response during bacterial infections. We have also previously shown that lithium chloride (LiCl), a GSK3 inhibitor suppressed development of Plasmodium berghei in a murine model of malarial infection. The present study is aimed at evaluating G. truncata for its anti-malarial and anti-inflammatory effects using in vivo malarial and melioidosis infection models respectively. In a four-day suppressive test, intraperitoneal injections of up to 250 mg/kg body weight (bw) G. truncata CME into P.berghei-infected mice suppressed parasitaemia development by >60%. Intraperitoneal administration of 150 mg/kg bw G. truncata CME into Burkholderia pseudomallei-infected mice improved survivability by 44%. G. truncata CME lowered levels of pro-inflammatory cytokines (TNF-α, IFN-γ) in serum and organs of B. pseudomallei-infected mice. In both infections, increased phosphorylations (Ser9) of GSK3β were detected in organ samples of animals administered with G. truncata CME compared to controls. Taken together, results from this study strongly suggest that the anti-malarial and anti-inflammatory effects elicited by G. truncata in part were mediated through inhibition of GSK3β. The findings provide scientific basis for the ethnomedicinal use of this fern to treat inflammation-associated symptoms

    Preparation of high performance SPEEK/Cloisite 15A nanocomposite membrane via advanced membrane formulation method

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    Sulfonated poly (ether ether ketone) (SPEEK)/Cloisite 15A® nanocomposite membranes were prepared via solution intercalation method. For better dispersion of nanoclay in the polymer matrix, the solution intercalation method was modified and a compatibilizer was introduced. The state of nanoclay dispersion was determined by FESEM. The effect of the solution formulation preparation method and compatibilizer on the performance properties such as proton conductivity and methanol permeability of all membranes was studied. FESEM analysis confirmed that SPEEK/Cloisite 15A® nanocomposite membrane prepared via modified solution intercalation method and in the presence of compatibilizer was the best membrane in terms of its morphological structure. Due to its well nanoclay distribution in polymer matrix, this kind of membrane exhibited the highest selectivity owing to its high proton conductivity and low methanol permeability. SPEEK/Cloisite 15A® with compatibilizer prepared via modified solution intercalation method was found to be the best membrane

    Characterisation of particle mass and number concentration on the east coast of the Malaysian Peninsula during the northeast monsoon

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    Particle mass concentrations (PM10, PM2.5 and PM1) and particle number concentration ((PNC); 0.27 μm ≤ Dp ≤ 34.00 μm) were measured in the tropical coastal environment of Bachok, Kelantan on the Malaysian Peninsula bordering the southern edge of the South China Sea. Statistical methods were applied on a three-month hourly data set (9th January to 24th March 2014) to study the influence of north-easterly winds on the patterns of particle mass and PNC size distributions. The 24-h concentrations of particle mass obtained in this study were below the standard values detailed by the Recommended Malaysian Air Quality Guideline (RMAQG), United States Environmental Protection Agency (US EPA) and European Union (EU) except for PM2.5, which recorded a 24-h average of 30 ± 18 μg m-3 and exceeded the World Health Organisation (WHO) threshold value (25 μg m-3). Principal component analysis (PCA) revealed that PNC with smaller diameter sizes (0.27-4.50 μm) showed a stronger influence, accounting for 57.6% of the variability in PNC data set. Concentrations of both particle mass and PNC increased steadily in the morning with a distinct peak observed at around 8.00 h, related to a combination of dispersion of accumulated particles overnight and local traffic. In addition to local anthropogenic, agricultural burning and forest fire activities, long-range transport also affects the study area. Hotspot and backward wind trajectory observations illustrated that the biomass burning episode (around February-March) significantly influenced PNC. Meteorological parameters influenced smaller size particles (i.e. PM1 and Dp (0.27-0.43 μm)) the most

    Removal of lead(II) from aqueous solution using polyacrylonitrile/zinc oxide activated carbon nanofibers

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    This study aimed to prepare activated carbon nanofibers (ACNFs) from polyacrylonitrile (PAN) and zinc oxide (ZnO) via electrospinning process for removal of lead from aqueous solution. The ACNFs/ZnO were characterized in term of its morphological changes, specific surface area and functional groups analysis using Field Emission Scanning Electron Microscope (FESEM), Brunauer–Emmett–Teller (BET) and Fourier Transform Infrared (FTIR) analysis, respectively. The results showed that the specific surface area (SSA) of the ACNFs/ZnO were higher than the neat ACNFs which were 163.04 m2/g as compared to 67.6 m2/g, accordingly. FESEM analysis illustrated that composite ACNFs possessed more compact fibers with presence of ZnO beads and smaller fiber diameter whereas neat ACNFs possessed more aligned nanofibers with larger fiber diameter. Adsorption study showed that the composite ACNFs possessed higher capacity which was 120.3 mg/g as compared to 77.6 mg/g of neat ACNFs. This excellent adsorption performance of ACNFs PAN/ZnO exhibits the potential of this composite adsorbent to solve the environmental issue of heavy metal contamination. © 2017, Malaysian Society of Analytical Sciences

    Re-Thinking Sustainable Development within Islamic Worldviews: A Systematic Literature Review

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    Many models of economic growth and sustainable development like circular economy, doughnut economy, and sharing economy were articulated to address the global issues including poverty, climate change, and inequity. However, these models were not informed by traditional value-based worldviews. This systematic literature review aims to gain insights on the different models, practices, and drivers for Islamic sustainable development to inform a new discourse for sustainability. Besides, it intends to define emerging themes in sustainable development and explore the viability for adopting Islamic development models to promote inclusive, pro-poor, and human-centred development. The methodology adopted is systematic literature review to identify sustainability models, practices, and drivers in Islam. Policy recommendations and strategic directions are outlined based on the review

    Adsorption and photocatalytic study of integrated photocatalyst adsorbent (IPCA) using LaFeO3-GO nanocomposites for removal of synthetic dyes

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    In this research, Lanthanum Orthoferrite-Graphene Oxide(LaFeO3-GO)IPCA nanocomposites were synthesised via sol-gel glucose method. Fourier Transform Infrared Spectroscopy(FTIR), Autopore Porosimeter and UV-Vis Spectrophotometer measurement were used for the characterisation of the nanocomposites. The effect of certain ratios of GO deposited on LaFeO3 were investigated for removal of methylene blue and methyl orange dyes through adsorption-photocatalytic activity. Among all samples, excellent removal of methylene blue could be observed in 5% GO in LaFeO3-GO IPCA nanocomposites that demonstrated 100 % degradation efficiency within 60 min under visible light irradiation. For adsorption under dark condition, 2% GO in LaFeO3-GO nanocomposites achieved 98% removal of methyl orange within 2 h. It could be concluded that synergetic effect between photocatalysis and adsorption can give significant impact for removal of synthetic dyes from aqueous solution

    Preparation and physicochemical properties of zeolitic imidazolate framework-8 (ZIF-8)/rice husk derived graphene (GRHA) nanohybrid composites

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    This paper proposes an improve nanohybrid composites of Zeolitic Imidazolate Framework-8 (ZIF-8)/Rice husk Derived Graphene (GRHA). The main goal of this work is to prepare the nanohybrid composites with high surface area and enhanced porosity. The composite is prepared via aqueous room temperature method which is simple and fast. Based on Fourier transform Infrared (FTIR) and X-ray Diffraction (XRD) analysis, it shows that the produced ZIF- 8 is in sodalite (SOD) structure while GRHA is in amorphous due to the presence of multilayer graphene. Raman analysis shows that the prepared GRHA has a high degree of graphitization. The BET specific surface area (BETSSA) is found to increase up to three times higher (1632.10 m2/g) as compared to pristine GRHA (518.11 m2/g) and ZIF-8 (687.32 m2/g) respectively. Therefore, it is envisaged that this composite can be very useful for hydrogen storage

    Impact of regional haze towards air quality in Malaysia: A review

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    Haze is a common phenomenon afflicting Southeast Asia (SEA), including Malaysia, and has occurred almost every year within the last few decades. Haze is associated with high level of air pollutants; it reduces visibility and affects human health in the affected SEA countries. This manuscript aims to review the potential origin, chemical compositions, impacts and mitigation strategies of haze in Malaysia. “Slash and burn” agricultural activities, deforestation and oil palm plantations on peat areas, particularly in Sumatra and Kalimantan, Indonesia were identified as the contributing factors to high intensity combustions that results in transboundary haze in Malaysia. During the southwest monsoon (June to September), the equatorial SEA region experiences a dry season and thus an elevated number of fire events. The prevailing southerly and south-westerly winds allow the cross-boundary transportation of pollutants from the burning areas in Sumatra and Kalimantan in Indonesia, to Peninsular Malaysia and Malaysian Borneo, respectively. The dry periods caused by the El Niño - Southern Oscillation (ENSO) prolong the duration of poor air quality. The size range of particulate matter (PM) in haze samples indicates that haze is dominated by fine particles. Secondary inorganic aerosols (SIA, such as SO42- and NH4+) and organic substances (such as levoglucosan, LG) were the main composition of PM during haze episodes. Local vehicular emissions and industrial activities also contribute to the amount of pollutants and can introduce toxic material such as polyaromatic hydrocarbons (PAHs). Haze episodes have contributed to increasing hospital visits for treatments related to chronic obstructive pulmonary diseases, upper respiratory infections, asthma and rhinitis. Respiratory mortality increased 19% due to haze episodes. Children and senior citizens are more likely to suffer the health impacts of haze. The inpatient cost alone from haze episodes was estimated at around USD 91,000 per year in Malaysia. Almost all economic sectors also experienced losses, with the heaviest losses in the agriculture and tourism sectors. This review suggests several ways forward to reduce haze episodes in SEA and Malaysia. These include economic approaches, research collaborations and science-policy interface. Improving forecasting capabilities can help reduce response time to burning events and subsequently reduce its impacts. Lastly, commitment and involvement by individuals, government agencies, and the entrepreneurial private sectors are crucial to reduce biomass burning (BB) and haze episodes in SEA
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