64 research outputs found

    Enhancement of cyanobacterial control by fungi degraded palm oil trunk

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    The elliptic azimuthal anisotropy coefficient (v2) is measured for charm (D0) and strange (K0 S, Λ, Ξ−, and Ω−) hadrons, using a data sample of p þ Pb collisions collected by the CMS experiment, at a nucleonnucleon center-of-mass energy of ffiffiffiffiffiffiffi sNN p ¼ 8.16 TeV. A significant positive v2 signal from long-range azimuthal correlations is observed for all particle species in high-multiplicity p þ Pb collisions. The measurement represents the first observation of possible long-range collectivity for open heavy flavor hadrons in small systems. The results suggest that charm quarks have a smaller v2 than the lighter quarks, probably reflecting a weaker collective behavior. This effect is not seen in the larger PbPb collision system at ffiffiffiffiffiffiffi sNN p ¼ 5.02 TeV, also presented

    First report of anatoxin-a encoding gene in isolated cyanobacterial strains from Malaysia

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    Aims: This study focus on the presence of cyanobacterial toxin in Malaysia and anatoxin-a-encoding gene was detected in this study and the status of cyanobacterial toxins in Malaysia can now be clarified. Methodology and results: As part of status determination of cyanobacterial toxins in Malaysia, cyanobacterial strains have been isolated from different environments and identified using cyanobacterial 16S rRNA gene sequence. PCR assay was carried out to detect the presence of cyanobacterial toxin-encoding genes in these isolated strains by amplifying genes encoded for microcystin, anatoxin-a, cylindrospermopsin and saxitoxin. Using molecular identification of 16S rRNA gene sequences, a total of forty-two cyanobacterial strains were identified, which belongs to eighteen different genera of Synechococcus, Cyanobium, Synechocystis, Chroococcidiopsis, Leptolyngbya, Nodosilinea, Limnothrix, Pseudanabaena, Cephalothrix, Aerosakkonema, Oscillatoria, Alkalinema, Pantanalinema, Planktolyngbya, Scytonema, Nostoc, Hapalosiphon and Symphyonemopsis. The toxicity of these strains was tested using PCR amplification of toxin-encoding genes using specific primers. Conclusion, significance and impact of study: Anatoxin-a (ATX) gene, which involved in the biosynthesis of anatoxin-A was detected in two isolated strains namely Limnothrix sp. B15 and Leptolyngbya sp. D1C10. This study focus on the the presence of cyanobacterial toxin in Malaysia can now be determined as potential threat because anatoxin-a-encoding gene was detected in this study and the status of cyanobacterial toxins in Malaysia can now be clarified. © 2018, Universiti Sains Malaysia

    Determination of total phenolic content, total flavonoid content and antioxidant activity of various organic crude extracts of licuala spinosa leaves from Sabah, Malaysia

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    In this study, the leaves of Licuala spinosa were used to determine the total phenolic and flavonoid content as well as antioxidant activity of different crude extracts. The samples were extracted successively with organic solvents such as hexane, chloroform and ethyl acetate respectively. The total phenolic content was determined by Folin-Ciocalteu’s assay. Chloroformcrude extract showed the highest total phenolic content (9.42± 0.06 mg GAE/g), followed by ethylacetate crude extract (8.91± 0.06 mg GAE/g) and hexane crude extract (6.78±0.26 mg GAE/g).The total flavonoid content was determined by Aluminium chloride colometric assay and expressedas QE equivalent. Chloroform crude extract showed the highest total flavonoid content (8.96 ± 0.21mg QE/g), followed by ethyl acetate crude extract (7.04 ± 0.02 mg QE/g) and hexane crude extract(3.05 ± 0.09 mg QE/g). The antioxidant activity of extracts were evaluated by 2,2-diphenyl-1-picyhydrazyl (DPPH) assay. In DPPH assay, IC50 values were used to determine the antioxidant potential of the sample. The lower the IC50 value, the higher the antioxidative property. Among allthe extracts, chloroform extracts exhibited higher DPPH radical scavenging activity with IC50 value of 0.032 mg /mL. BHT used as the positive control showed IC50 value of 0.089 mg/m

    Bioremediation and Electricity Generation by Using Open and Closed Sediment Microbial Fuel Cells

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    The industrial contamination of marine sediments with mercury, silver, and zinc in Penang, Malaysia was studied with bio-remediation coupled with power generation using membrane less open (aerated) and closed (non-aerated) sediment microbial fuel cells (SMFCs). The prototype for this SMFC is very similar to a natural aquatic environment because it is not stimulated externally and an oxygen sparger is inserted in the cathode chamber to create the aerobic environment in the open SMFC and no oxygen supplied in the closed SMFC. The open and closed SMFCs were showed the maximum voltage generation 300.5 mV (77.75 mW/m2) and 202.7 mV (45.04 (mW/m2), respectively. The cyclic voltammetry showed the oxidation peak in open SMFCs at +1.9 μA and reduction peak at -0.3 μA but in closed SMFCs oxidation and reduction peaks were noted at +1.5 μA and -1.0 μA, respectively. The overall impedance (anode, cathode and solution) of closed SMFCs was higher than open SMFCs. The charge transfer impedance showed that the rates of substrate oxidation and reduction were very low in the closed SMFCs than open SMFCs. The Nyquist arc indicated that O2 act as electron acceptor in the open SMFCs and CO2 in the closed SMFCs. The highest remediation efficiency of toxic metals [Hg (II) ions, Zn (II) ions, and Ag (I) ions] in the open SMFCs were 95.03%, 86.69%, and 83.65% in closed SMFCs were 69.53%, 66.57%, and 65.33%, respectively, observed during 60–80 days. The scanning electron microscope and 16S rRNA analysis showed diverse exoelectrogenic community in the open SMFCs and closed SMFCs. The results demonstrated that open SMFCs could be employed for the power generation and bioremediation of pollutants

    Propiedades físico-químicas de mezclas de oleina de palma con otros aceites vegetales

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    Palm oil (olein) was blended with other edible oils for the enhancement of its market acceptability in terms of melting point depression and shelf life. The physico-chemical properties like viscosity, density, melting behavior, peroxide value (PV), saponification value (SV) and iodine value (IV) of four different binary blends with four vegetable oils were evaluated. Palm olein was found to be more stable against rancidity than the other oils. For the stability against oxidation and melting point depression the palm olein-canola (PO/CO) blend was found to be better than the others. The Differential Scanning Calorimeter (DSC) thermogram of the melting behavior of the blends traces some new polymorphs of the triglyceride. This study will help the oil producing industry to find out the most economically viable oil blends for cooking purposes, with maximum nutrition as well as desirable physico-chemical properties.Aceite de palma (oleína) fue mezclada con otros aceites comestibles para aumentar su aceptabilidad en el mercado en términos de descenso del punto de fusión y mejora de su almacenamiento. Las propiedades físico-químicas tales como viscosidad, densidad, comportamiento en la fusión, valor de peróxidos (PV), valor de saponificación (SV) e índice de yodo (IV) de cuatro diferentes mezclas binarias con cuatro aceites vegetales fueron evaluadas. La oleína de palma fue más estable frente a la rancidez que otros aceites. En la estabilidad frente la oxidación y el descenso del punto de fusión, la mezcla de oleína de palma/canola (PO/CO) fue mejor que las otras. Los termogramas del calorímetro diferencial de barrido (DSC) referidos al comportamiento de fusión de las mezclas indican algunos nuevos polimorfismos de los triglicéridos. Este estudio podría ayudar a las empresas que elaboran aceites a encontrar los aceites económicamente más viables para cocinar, con buenas propiedades nutricionales, así como con unas propiedades físico-químicas deseables

    GC-MS analysis of chemical constituents and in vitro antioxidant activity of the organic extracts from the stem of Bridelia stipularis

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    In the present study the stems of the Bridelia stipularis (L.) Blume, which is traditionally used by ethnic communities in Sabah, Malaysia, has been investigated for its chemical composition, total flavonoid content (TFC) and total phenolic content (TPC) via Gas-Chromatography-Mass Spectroscopy (GC-MS) analysis consuming hexane, chloroform and ethyl acetate as extraction solvents and gallic acid and quercetin as internal standards. In vitro antioxidant activity (AA) was determined by the application of 1,1-diphenyl-2-picryl hydrazine (DPPH) radical scavenging assay using tert-butyl-1-hydroxytoluene (BHT) as comparative drug. The GC-MS profiling showed the presence of 1-dodecanol (40.917%), oxalic acid, cyclobutyl octadecyl ester (24.985%), 1-octanol,2-nitro (12.424%), benzaldehyde, 2,4-dimethyl- (9.583%), 4-tridecanol (6.359%) and nitric acid, nonyl ester (5.616%) as major constituents. The TPC (224.62 ± 0.08 mg QE/g) and TFC (160.48 ± 0.08 mg GAE/g) was reported highest for the most polar solvent i.e. ethyl acetate. The in vitro antioxidant study disclosed highest IC50 value for ethyl acetate (2.15 mg/mL), queued by chloroform (1.19 mg/mL) and hexane (0.89 mg/mL), displaying that polar solvents are good extraction solvents for the identification of free radical scavenging properties, TFC and TPC

    Role of Post-Hydrothermal Treatment on the Microstructures and Photocatalytic Activity of TiO2-Based Nanotubes

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    The present study demonstrates the thermal stability and photocatalytic activity of TiO2-based nanotubes with respect to post-hydrothermal treatment. Titanate nanotubes were synthesized by adapting an alkali hydrothermal method from TiO2sol using NaOH as a catalyst. The effect of post-hydrothermal heating on the properties—such as structure, morphology, textural properties, and activity—of as-synthesized one-dimensional titania nanostructure is investigated in detail. The characterizations are carried out using SEM, EDX, TEM, XRD, and a BET surface area analyzer. When heated in the presence of water in an autoclave, the protonated titanate phase of the nanotubes converts to anatase phase. Meanwhile, the tubular morphology is gradually lost as the post-hydrothermal heating duration increases. The photocatalytic activity was assessed utilizing the photo-oxidation of an amaranth dye. It is discerned that the as-prepared nanotubes are photocatalytically inactive but become active after post-hydrothermal processing. The activity trend follows the formation of the active phase—the titanate phase crystallizes into a photocatalytically-active anatase phase during post-hydrothermal heating. The effect of experimental parameters, such as reaction pH, dye concentration, and amount of catalyst, on the dye removal is studied. The findings also highlight that the role of holes/OH•− is more prominent as compared to conduction band electron/O2•− for the removal of the dye. In addition, the photocatalyst exhibited excellent stability and reusability.Theauthorswouldliketoexpresstheir appreciation to Ministry of Higher Education Malaysia for Fundamental Research Grant SchemewithProject Code: FRGS/1/2019/STG07/USM/02/12

    A Review on Cadmium and Lead Contamination: Sources, Fate, Mechanism, Health Effects and Remediation Methods

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    Cadmium and lead soil contamination is a widespread environmental problem that requires profound and sustainable solutions. These toxic elements can be naturally occurring on the Earth’s crust or from man-made origins. Cadmium and lead could accumulate and translocate in soil over the long term. Thus, their risk of entering the food chain is extremely elevated and their effects on the living organisms in the food web are of great concern. The main purpose of this review study is to emphasize the risk to human health of cadmium and lead as an environmental contaminant in soil and plants. Human exposure to cadmium and lead can cause severe illness; for instance, long-term exposure to cadmium can alter kidney health and cause dysfunction. Additionally, lead threatens the nervous system and causes countless diseases. Hence, the remediation of cadmium and lead from soil before they enter the food chain remains essential, and regular monitoring of their principal sources is crucially needed for a sustainable soil ecosystem

    Utilization of green sophorolipids biosurfactant in reverse micelle extraction of antibiotics: kinetic and mass transfer studies

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    Reverse micelle extraction of erythromycin and amoxicillin were studied by using eco-friendly sophorolipids biosurfactant. Application of biosurfactant can further improve reverse micelle extraction in terms of sustainability and environmental friendliness compared to synthetic surfactants. The mass transfer behavior of the antibiotics during reverse micelle extraction was investigated. Experimental results show that the reverse micelle extraction of amoxicillin and erythromycin were completed within 200 s. The range of combined mass transfer coefficients obtained is 1.748 × 10−8 to 1.064 × 10−7 for reverse micelle extraction of amoxicillin and 3.395 × 10−7 to 1.131 × 10−6 for erythromycin. The rate limiting steps for each extraction process were identified. The overall mass transfer coefficients of backward extraction were found to be lower than that of forward extraction for both antibiotics which indicates that the forward extraction process was more efficient and faster than the backward extraction. Comparisons between erythromycin and amoxicillin showed that erythromycin has better equilibrium partitioning and larger calculated overall mass transfer coefficients compared to amoxicillin. This may be due to some differences in behaviors and characteristics of amoxicillin and erythromycin during the reverse micelle extraction process. This reverse micelle extraction method was found to be more efficient in extracting erythromycin compared to amoxicillin
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