178 research outputs found

    Efficient Photoelectrochemical Performance of Gamma Irradiated gC3N4 and its g-C3N4@BiVO4 Heterojunction for Solar Water Splitting

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    This is the author accepted manuscript. The final version is available from the American Chemical Society via the DOI in this recordComprehensive experimental and density functional theory simulations have been performed for the enhanced photoelectrochemical performance of gamma irradiated g-C3N4 and its heterojunction with BiVO4. The structure and morphology of g-C3N4@BiVO4 as a heterojunction were analyzed and verified from the correlation of experimental and theoretical data. It is found that gamma radiations have changed the bonding structure of g-C3N4 which ultimately reduces the optical bandgap energy. Moreover, the performance of gamma-irradiated g-C3N4 is two-fold, compared to that of non-irradiated one; increases from 3.59 to 5.86 µAcm-2 at 1.23 V versus Ag/AgCl in 0.5 M Na2SO4 electrolyte solution (pH 7). Finally, it is observed that the performance of gamma irradiated g-C3N4 in g-C3N4@BiVO4 heterojunction increased from 0.53 mA cm-2 to 1.38 mA cm-2, compared to that of the non–irradiated one. In summary, it has been concluded that gamma-irradiated g-C3N4 and its heterojunction is potentially be applied in PEC solar water splitting.National University of Malaysi

    An ultraviolet B condition that affects growth and defense in Arabidopsis

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    Ultraviolet B light (UV-B, 280-315 nm) is the shortest wavelength of the solar spectrum reaching the surface of the Earth. It has profound effects on plants, ranging from growth regulation to severe metabolic changes. Low level UV-B mainly causes photomorphogenic effects while higher levels can induce stress, yet these effects tend to overlap. Here we identified a condition that allows growth reduction without obvious detrimental stress in wild type Arabidopsis rosette plants. This condition was used to study the effects of a daily UV-B dose on plant characteristics of UV-B adapted plants in detail. Exploration of the transcriptome of developing leaves indicated downregulation of genes involved in stomata formation by UV-B, while at the same time genes involved in photoprotective pigment biosynthesis were upregulated. These findings correspond with a decreased stomatal density and increased UV-B absorbing pigments. Gene ontology analysis revealed upregulation of defense related genes and meta-analysis showed substantial overlap of the UV-B regulated transcriptome with transcriptomes of salicylate and jasmonate treated as well as herbivore exposed plants. Feeding experiments showed that caterpillars of Spodoptera littoralis are directly affected by UV-B, while performance of the aphid Myzus persicae is diminished by a plant mediated process

    Rectoanal intussusception presenting as prolapsed anal mass

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    INTRODUCTION: Rectoanal intussusception is an invagination of the rectal wall into the lumen of the rectum. It is very rare to present as mass protruding from the anus. METHODS: We report a case of very rare presentation of adult rectoanal intussusception. CASE REPORT A 54 years-old healthy lady with presenting complain of mass protruding from the anus and per rectal bleeding for one day prior. Clinical examination revealed prolapsed anal mass with carpet like polyp and abundance of mucus discharge. There was no abdominal mass or tenderness. Mass was successfully reduced manually. Colonoscopy showed polypoidal growth at the rectum at 8cm from anus and biopsy was taken. we proceed with low anterior resection and intraoperatively noted rectoanal intussusception. Histopathological examination did showed tubullovilious adenoma with low grade dysplasia. Post-operative course complicated with anastomotic leak which required laparotomy, washout and drainage. She was then discharged well on post-operative day 13. CONCLUSION Rectoanal intussusception can present as prolapse through the anus in adults on rare occasions and should be investigated before definitive treatment. To preserve sphincter function, an initial reduction of colorectal intussusception should be attempted before surgery

    Sal-type ABC-F proteins: intrinsic and common mediators of pleuromutilin resistance by target protection in staphylococci

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    The first member of the pleuromutilin (PLM) class suitable for systemic antibacterial chemotherapy in humans recently entered clinical use, underscoring the need to better understand mechanisms of PLM resistance in disease-causing bacterial genera. Of the proteins reported to mediate PLM resistance in staphylococci, the least-well studied to date is Sal(A), a putative ABC-F NTPase that—by analogy to other proteins of this type—may act to protect the ribosome from PLMs. Here, we establish the importance of Sal proteins as a common source of PLM resistance across multiple species of staphylococci. Sal(A) is revealed as but one member of a larger group of Sal-type ABC-F proteins that vary considerably in their ability to mediate resistance to PLMs and other antibiotics. We find that specific sal genes are intrinsic to particular staphylococcal species, and show that this gene family is likely ancestral to the genus Staphylococcus. Finally, we solve the cryo-EM structure of a representative Sal-type protein (Sal(B)) in complex with the staphylococcal 70S ribosome, revealing that Sal-type proteins bind into the E site to mediate target protection, likely by displacing PLMs and other antibiotics via an allosteric mechanism

    Health literacy and hand hygiene practice: A factor analysis approach

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    The aim of this study is to identify the factors associated with health literacy and hand hygiene practice. This study also would like to examine the existence of gender differences for factors associated with health literacy and hand hygiene practice. Questionnaire was used to collect the data. Number of respondents for this study was 302. The methodology used in this study were analysis factor, normality test and non-parametric technique using Mann-Whitney test. The results showed five factors associated with health literacy and hand hygiene practice extracted using analysis factor. The Mann-Whitney test results showed there was no mean rank difference between male and female respondents of each factor associated with health literacy and hand hygiene practice

    Enhanced hydrogen evolution reaction performance of anatase–rutile TiO2 heterojunction via charge transfer from rutile to anatase

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    This is the final version. Available on open access from the Royal Society of Chemistry via the DOI in this recordIn light of recent doubts surrounding the industrial viability of photo(electro)catalysis technology for sustainable hydrogen production, it becomes imperative to align materials development with rationalized synthesis protocols. In this study, we present an innovative technique utilizing atmospheric-pressure chemical vapor deposition (APCVD) to rapidly produce TiO2 in just 5 minutes using pure TiCl4 as the sole reagent. The resulting photoanode exhibits exceptional photoelectrochemical (PEC) water-splitting performance, achieving a photocurrent density of 2.06 mA cm−2 at 1.23 V RHE. Moreover, the photoanode demonstrates sustained operation for 16 hours, leading to the successful collection of 138 μmol of H2 and 62 μmol of O2. These remarkable results are attributed to the controlled formation of an anatase–rutile phase-junction, the presence of well-balanced oxygen vacancies, and the bifrustum nanoparticle–nanoflake structure with a unique light trapping effect and large surface area. Density functional theory calculations confirm that the water-splitting reaction primarily occurs at undercoordinated Ti and O atoms in both anatase and rutile TiO2. Notably, the calculated Gibbs free energy values for the hydrogen evolution reaction (HER) differ significantly between rutile (−0.86 eV) and anatase TiO2 (0.22 eV). In the heterojunction, charge transfer enhances the HER performance through shared electronic density, resulting in a synergistic effect that surpasses the capabilities of individual surfaces and underscores the importance of electronic interactions within the junction.Universiti Kebangsaan MalaysiaCenter of Excellence for Innovation in ChemistryProgram Management Unit for Human Resources & Institutional Development, Research and InnovationHuman Resource Development in Science Project Science Achievement Scholarship of Thailand (SAST

    IFSS, TG, FT-IR spectra of impregnated sugar palm (Arenga pinnata) fibres and mechanical properties of their composites.

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    This study aimed to investigate the effect of resin impregnation on the interfacial shear strength (IFSS), thermogravimetric (TG) and fourier transform infrared (FT-IR) of sugar palm (Arenga pinnata) fibres. In addition, the effect of resin impregnation on the mechanical properties of sugar palm fibre reinforced unsaturated polyester (UP) composites was also studied. The fibres were impregnated with UP via vacuum resin impregnation process at a pressure of 600 mmHg for 5 min. Composites of 10, 20, 30, 40 and 50 % fibre loadings were fabricated and tested for tensile and flexural properties. It was observed that the impregnation process caused the fibres to be enclosed by UP resin and this gave a strong influence to the increase of its interfacial bonding by the increase of its IFSS from single fibre pull-out test. It was also observed with TG and FT-IR spectra that the impregnated fibre had lower moisture uptake than the control and there was no significant increase in thermal stability of the impregnated fibre. The sequence of fibre decomposition started from the evaporation of moisture, hemicelluloses, cellulose, lignin and finally ash content and the presence of these components were proven by FT-IR spectra. For the composite specimens, due to the high interfacial bonding of the impregnated fibre and the matrix, the impregnated composites showed consistently higher tensile strength, tensile modulus, elongation at break, flexural strength, flexural modulus and toughness than the control samples. It was also observed that 30 % fibre loading gave optimum properties

    Elemental hydrochemistry assessment on its variation and quality status in Langat River, Western Peninsular Malaysia.

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    This paper discusses the hydrochemistry variation and its quality status in Langat River, based on the chemistry of major ions, metal concentrations and suitability for drinking purposes. Water samples were collected from 30 different stations to assess their hydrochemical characteristics. The physico-chemical parameters selected were temperature, electrical conductivity, total dissolved solids (TDS), salinity, dissolved oxygen , pH, redox potential, HCO3, Cl, SO4, NO3, Ca, Na, K, Mg, 27Al, 138Ba, 9Be, 111Cd, 59Co, 63Cu, 52Cr, 57Fe, 55Mn, 60Ni, 208Pb, 80Se and 66Zn to investigate the variation of the constituents in the river water. Most of the parameters comply with the Drinking Water Quality Standard of the World Health Organization and the Malaysian National Standard for Drinking Water Quality by the Malaysia Ministry of Health except for EC, TDS, Cl, HCO3, SO4, Na, Mg, Al, Fe and Se. The results show that the Langat River is unsuitable for drinking purposes directly without treatment
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