Displaying publications 1 - 20 of 140 in total

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  1. Tan ST, Ali Umar A, Balouch A, Nafisah S, Yahaya M, Yap CC, et al.
    ACS Comb Sci, 2014 Jul 14;16(7):314-20.
    PMID: 24919039 DOI: 10.1021/co400157m
    This Research Article reports an unusually high efficiency heterogeneous photodegradation of methyl orange (MO) in the presence of Ag nanoparticle-loaded ZnO quasi-nanotube or nanoreactor (A-ZNRs) nanocatalyst grown on FTO substrate. In typical process, photodegradation efficiency of as high as 21.6% per μg per Watts of used catalyst and UV power can be normally obtained within only a 60-min reaction time from this system, which is 10(3) order higher than the reported results. This is equivalent to the turnover frequency of 360 mol mol(-1) h(-1). High-density hexagonal A-ZNRs catalysts were grown directly on FTO substrate via a seed-mediated microwave-assisted hydrolysis growth process utilizing Ag nanoparticle of approximately 3 nm in size as nanoseed and mixture aqueous solution of Zn(NO3)·6H2O, hexamethylenetetramine (HMT), and AgNO3 as the growth solution. A-ZNRs adopts hexagonal cross-section morphology with the inner surface of the reactor characterized by a rough and rugged structure. Transmission electron microscopy imaging shows the Ag nanoparticle grows interstitially in the ZnO nanoreactor structure. The high photocatalytic property of the A-ZNRs is associated with the highly active of inner side's surface of A-ZNRs and the oxidizing effect of Ag nanoparticle. The growth mechanism as well as the mechanism of the enhanced-photocatalytic performance of the A-ZNRs will be discussed.
    Matched MeSH terms: Ultraviolet Rays
  2. Jaganathan SK, Prasath MM
    An Acad Bras Cienc, 2018 4 12;90(1):195-204.
    PMID: 29641759 DOI: 10.1590/0001-3765201820170736
    Demand for medical implants is rising day by day as the world becomes the place for more diseased and older people. Accordingly, in this research, metallocene polyethylene (mPE), a commonly used polymer was treated with UV rays for improving its biocompatibility. Scanning electron microscopy (SEM) images confirmed the formation of crests and troughs, which depicts the improvement of surface roughness of mPE substrates caused by UV etching. Accordingly, the contact angle measurements revealed that the wettability of mPE-2.5 J/cm2 (68.09º) and mPE-5 J/cm2 (57.93º) samples were found to be increased compared to untreated mPE (86.84º) indicating better hydrophilicity. Further, the UV treated surface exhibited enhanced blood compatibility as determined in APTT (untreated mPE- 55.3 ± 2.5 s, mPE-2.5 J/cm2 - 76.7 ± 4.1 s and mPE-5 J/cm2 - 112.3 ± 2 s) and PT (untreated mPE - 24.7 ± 1.5 s, mPE- 2.5 J/cm2 - 34.3 ± 1.1 s and mPE-5 J/cm2 - 43 ± 2 s) assay. Moreover, the treated mPE-2.5 J/cm2 (4.88%) and mPE-5 J/cm2 (1.79%) showed decreased hemolytic percentage compared to untreated mPE (15.40%) indicating better safety to red blood cells. Interestingly, the changes in physicochemical properties of mPE are directly proportional to the dosage of the UV rays. UV modified mPE surfaces were found to be more compatible as identified through MTT assay, photomicrograph and SEM images of the seeded 3T3 cell population. Hence UV-modified surface of mPE may be successfully exploited for medical implants.
    Matched MeSH terms: Ultraviolet Rays*
  3. Al-Naggar RA
    Asian Pac J Cancer Prev, 2013;14(8):4577-81.
    PMID: 24083705
    BACKGROUND: The objective of this study was to determine the practice of skin cancer prevention among Malaysian road traffic police officers.

    MATERIALS AND METHODS: This cross-sectional study involved 202 Malaysian Road Police Traffic officers. Inclusion criteria were those officers who work wearing white uniform regulating traffic. The survey took place at the Police Traffic Station, Jln Tun H.S. Lee, Kuala Lumpur, the main Head Quarters of Malaysian's Traffic Department where almost 600 police traffic officers are employed. The police traffic officers are given the task to take care of the traffic from the main office of the police station, then, according to the task, the officers drive to their given location for their duty. Each task is approved by the Chief Traffic Inspector of Kuala Lumpur. Data collected in this study were analyzed using SPSS 13, with the T-test for univariate analysis and multiple linear regression for multivariate analysis.

    RESULTS: A total of 202 road traffic police officers participated. The majority were older than 30 years of age, male, Malay, married, with secondary education, with monthly income more than 2000 Ringgit Malaysia (66.3%, 91.1%, 86.6%, 84.7%, 96%, 66.3%; respectively). Regarding the practice of skin cancer prevention, 84.6% of the study participants were found to wear hats, 68.9% sunglasses and 85.6% clothing that covering most of the body but only 16.9% used a sunscreen when they were outdoors. When analysis of the factors that influenced the practice of skin cancer prevention was performed, univariate analysis revealed that gender, age and monthly income significantly influenced the practice of skin cancer prevention. For multivariate analysis, gender, monthly income and race significantly influenced the practice of using sunscreen among road traffic police officers (p<0.001, p=0.019, p=0.027; respectively).

    CONCLUSIONS: The practice of skin cancer prevention among the traffic police officers showed good practices in terms of wearinga hat, sun glasses and clothing that covers most of the body. However, the study revealed a poor practice of the use of sunscreen. The factors that influence the practice of sunscreen use were found to be gender, income, and race. The study suggests that more awareness campaign among traffic police officers is needed. Providing sunscreen for free for police traffic officers should be considered by the Police authorities.

    Matched MeSH terms: Ultraviolet Rays/adverse effects*
  4. Al-Naggar RA, Al-Naggar TH, Bobryshev YV
    Asian Pac J Cancer Prev, 2011;12(4):995-9.
    PMID: 21790240
    INTRODUCTION: Malignant melanoma in particular is one of the few remaining cancers with an increasing incidence.

    OBJECTIVES: The objective of this study is to explore the perceptions and opinions of young Malaysians towards skin cancer prevention.

    METHODOLOGY: Focus group discussions were conducted among 33 medical science students from Management and Science University (MSU), Shah Alam, Malaysia, using convenience sampling. Students were divided into 4 focus groups consisting of 8, 8, 9 and 8 students respectively. The facilitator wrote down the conversations and data obtained were classified into various categories and analyzed manually.

    RESULTS: The majority of the participants mentioned that overexposure to ultraviolet light is the commonest cause of skin cancer but also that the most benefit we get from sun ight is vitamin D synthesis. The majority mentioned that the best prevention measure for skin cancer is using a sunscreen, followed by limit exposure to the sun.

    CONCLUSION: The present study demonstrated there is a lack of knowledge regarding screening methods and prevention measures of skin cancer. Therefore, there is a need to establish health education unit in all universities to educate all university students regarding various health problems including skin cancer prevention.
    Matched MeSH terms: Ultraviolet Rays/adverse effects
  5. Ghazali AR, Muralitharan RV, Soon CK, Salyam T, Ahmad Maulana NN, Mohamed Thaha UAB, et al.
    Asian Pac J Cancer Prev, 2020 Nov 01;21(11):3381-3386.
    PMID: 33247699 DOI: 10.31557/APJCP.2020.21.11.3381
    BACKGROUND: Traditional cooling rice powder (bedak sejuk) is a fermented rice-based cosmetic that is applied topically on one's skin, as an overnight facial mask. According to user testimonies, bedak sejuk beautifies and whitens skin, whereby these benefits could be utilised as a potential melanoma chemopreventive agent.

    OBJECTIVE: Hence, this study aimed to determine the effects of bedak sejuk made from Oryza sativa ssp. indica (Indica) and Oryza sativa ssp. japonica (Japonica) on UVB-induced B164A5 melanoma cells, and also identify the antioxidant capacities of both types of bedak sejuk.

    METHODS: The optimum dose of Indica and Japonica bedak sejuk to treat the cells was determined via the MTT assay. Then, the antioxidant capacities of both types of bedak sejuk were determined using the FRAP assay.

    RESULTS: From the MTT assay, it was found that Indica and Japonica bedak sejuk showed no cytotoxic effects towards the cells. Hence, no IC50 can be obtained and two of the higher doses, 50 and 100 g/L were chosen for treatment. In the FRAP assay, Indica bedak sejuk at 50 and 100 g/L showed FRAP values of 0.003 ± 0.001 μg AA (ascorbic acid)/g of bedak sejuk and 0.004 ± 0.0003 μg AA/g of bedak sejuk. Whereas Japonica bedak sejuk at 50 g/L had the same FRAP value as Indica bedak sejuk at 100 g/L. As for Japonica bedak sejuk at 100 g/L, it showed the highest antioxidant capacity with the FRAP value of 0.01 ± 0.0007 μg AA/g of bedak sejuk which was statistically significant (p < 0.05) when compared to other tested concentrations.

    CONCLUSION: In conclusion, Japonica bedak sejuk has a higher antioxidant capacity compared to Indica bedak sejuk despite both being not cytotoxic towards the cells. Regardless, further investigations need to be done before bedak sejuk could be developed as potential melanoma chemoprevention agents.

    Matched MeSH terms: Ultraviolet Rays/adverse effects*
  6. Lah EF, Musa RN, Ho TM
    Asian Pac J Trop Biomed, 2012 Sep;2(9):679-83.
    PMID: 23569994 DOI: 10.1016/S2221-1691(12)60209-3
    To examined the immediate and 24 hours post- irradiation germicidal effects of UV-C lamp on eggs and adults of house dust mites Dermatophagoides pteronyssinus (D. pteronyssinus) and Dermatophagoides farinae (D. farinae).
    Matched MeSH terms: Ultraviolet Rays*
  7. Ibrahim MNM, Iqbal A, Shen CC, Bhawani SA, Adam F
    BMC Chem, 2019 Dec;13(1):17.
    PMID: 31384766 DOI: 10.1186/s13065-019-0537-3
    Titanium dioxide (TiO2) is added in sunscreens due to its ability to absorb ultraviolet (UV) light. However, upon irradiation of UV light, reactive oxygen species particularly hydroxyl radical which can damage human skin will be generated. In this study, lignin/TiO2 composites were employed to quench the hydroxyl radicals generated by the TiO2. The lignin was extracted from oil palm empty fruit bunch (OPEFB) via kraft and soda pulping processes. The kraft lignin composite was labelled as KL/TiO2 whereas the soda lignin composite was labelled as SL/TiO2. The lignins and the composites were characterized by FTIR, UV spectroscopy, 13C NMR, SEM, EDX, and XRD. The relative hydroxyl radical production of composites and TiO2 were compared through photo-oxidation of coumarin to 7-hydroxycoumarin as a test medium. The effect of types and amounts of lignin used were studied. The KL/TiO2 composite showed the least radical production due to higher phenolic hydroxyl content of kraft lignin. The activity of the hydroxyl radicals will be quenched when it abstract hydrogen atoms from the phenolic hydroxyl groups.
    Matched MeSH terms: Ultraviolet Rays
  8. Huwaidi A, Pathak N, Syahir A, Ikeno S
    Biochem Biophys Res Commun, 2018 09 05;503(2):910-914.
    PMID: 29928878 DOI: 10.1016/j.bbrc.2018.06.095
    Ultraviolet (UV) radiation causes damage in all living organisms, including DNA damage that leads to cell death. Herein, we provide a new technique for UV radiation protection through intracellular short peptide expression. The late embryogenesis abundant (LEA) peptide, which functions as a shield that protects macromolecules from various abiotic stress, was obtained from the Polypedilum vanderplanki group 3 LEA protein. Recombinant Escherichia coli BL21 (DE3) expressing functional LEA short peptide in vivo were exposed to UVA and UVC radiation for 4, 6, and 8 h. E. coli transformants expressing the LEA peptide showed higher cell viability under both UVA and UVC treatment at all time points as compared with that of the control. Furthermore, the cells expressing LEA peptide showed a higher number of colony-forming units per dilution under UVA and UVC treatment. These results suggested that expression of the short peptide could be useful for the development of genetically modified organisms and in applications that require resilience of organisms to UV radiation.
    Matched MeSH terms: Ultraviolet Rays*
  9. Zhu W, Zheng W, Hu X, Xu X, Zhang L, Tian J
    Biochim Biophys Acta Proteins Proteom, 2017 Apr;1865(4):404-413.
    PMID: 28087425 DOI: 10.1016/j.bbapap.2017.01.004
    Lonicera japonica Thunb., also known as Jin Yin Hua and Japanese honeysuckle, is used as a herbal medicine in Asian countries. Its flowers have been used in folk medicine in the clinic and in making food or healthy beverages for over 1500years in China. To investigate the molecular processes involved in L. japonica development from buds to flowers exposed to UV radiation, a comparative proteomics analysis was performed. Fifty-four proteins were identified as differentially expressed, including 42 that had increased expression and 12 that had decreased expression. The levels of the proteins related to glycolysis, TCA/organic acid transformation, major carbohydrate metabolism, oxidative pentose phosphate, stress, secondary metabolism, hormone, and mitochondrial electron transport were increased during flower opening process after exposure to UV radiation. Six metabolites in L. japonica buds and flowers were identified and relatively quantified using LC-MS/MS. The antioxidant activity was performed using a 1,1-diphenyl-2-picrylhydrazyl assay, which revealed that L. japonica buds had more activity than the UV irradiated flowers. This suggests that UV-B radiation induces production of endogenous ethylene in L. japonica buds, thus facilitating blossoming of the buds and activating the antioxidant system. Additionally, the higher metabolite contents and antioxidant properties of L. japonica buds indicate that the L. japonica bud stage may be a more optimal time to harvest than the flower stage when using for medicinal properties.
    Matched MeSH terms: Ultraviolet Rays*
  10. Saeedfar K, Heng LY, Chiang CP
    Bioelectrochemistry, 2017 Dec;118:106-113.
    PMID: 28780443 DOI: 10.1016/j.bioelechem.2017.07.012
    Multi-wall carbon nanotubes (MWCNTs) were modified to design a new DNA biosensor. Functionalized MWCNTs were equipped with gold nanoparticles (GNPs) (~15nm) (GNP-MWCNTCOOH) to construct DNA biosensors based on carbon-paste screen-printed (SPE) electrodes. GNP attachment onto functionalized MWCNTs was carried out by microwave irradiation and was confirmed by spectroscopic studies and surface analysis. DNA biosensors based on differential pulse voltammetry (DPV) were constructed by immobilizing thiolated single-stranded DNA probes onto GNP-MWCNTCOOH. Ruthenium (III) chloride hexaammoniate [Ru(NH3)6,2Cl(-)] (RuHex) was used as hybridization redox indicator. RuHex and MWCNT interaction was low in compared to other organic redox hybridization indicators. The linear response range for DNA determination was 1×10(-21) to 1×10(-9)M with a lower detection limit of 1.55×10(-21)M. Thus, the attachment of GNPs onto functionalized MWCNTs yielded sensitive DNA biosensor with low detection limit and stability more than 30days. Constructed electrode was used to determine gender of arowana fish.
    Matched MeSH terms: Ultraviolet Rays
  11. Hasan HA, Abdulmalek E, Rahman MBA, Shaari KB, Yamin BM, Chan KW
    Chem Cent J, 2018 Dec 20;12(1):145.
    PMID: 30570683 DOI: 10.1186/s13065-018-0509-z
    BACKGROUND: Although the development of antibiotic and antioxidant manufacturing, the problem of bacterial resistance and food and/or cosmetics oxidation still needs more efforts to design new derivatives which can help to minimize these troubles. Benzimidazo[1,2-c]quinazolines are nitrogen-rich heterocyclic compounds that possess many pharmaceutical properties such as antimicrobial, anticonvulsant, immunoenhancer, and anticancer.

    RESULTS: A comparative study between two methods, (microwave-assisted and conventional heating approaches), was performed to synthesise a new quinazoline derivative from 2-(2-aminophenyl)-1H-benzimidazole and octanal to produce 6-heptyl-5,6-dihydrobenzo[4,5]imidazo[1,2-c]quinazoline (OCT). The compound was characterised using FTIR, 1H and 13C NMR, DIMS, as well as X-ray crystallography. The most significant peak in the 13C NMR spectrum is C-7 at 65.5 ppm which confirms the cyclisation process. Crystal structure analysis revealed that the molecule grows in the monoclinic crystal system P21/n space group and stabilised by an intermolecular hydrogen bond between the N1-H1A…N3 atoms. The crystal packing analysis showed that the molecule adopts zig-zag one dimensional chains. Fluorescence study of OCT revealed that it produces blue light when expose to UV-light and its' quantum yield equal to 26%. Antioxidant activity, which included DPPH· and ABTS·+ assays was also performed and statistical analysis was achieved via a paired T-test using Minitab 16 software with P 

    Matched MeSH terms: Ultraviolet Rays
  12. Dzinun H, Othman MHD, Ismail AF
    Chemosphere, 2019 Aug;228:241-248.
    PMID: 31035161 DOI: 10.1016/j.chemosphere.2019.04.118
    Comparison studies in suspension and hybrid photocatalytic membrane reactor (HPMR) system was investigated by using Reactive Black 5 (RB5) as target pollutant under UVA light irradiation. To achieve this aim, hybrid TiO2/clinoptilolite (TCP) photocatalyst powder was prepared by solid-state dispersion (SSD) methods and embedded at the outer layer of dual layer hollow fiber (DLHF) membranes fabricated via single step co-spinning process. TiO2 and CP photocatalyst were also used as control samples. The samples were characterized by Scanning Electron Microscopy (SEM), Energy Dispersion of X-ray (EDX), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) analyses. The result shows that TCP was actively functioned as photocatalyst in suspension system and 86% of RB5 photocatalytic degradation achieved within 60 min; however the additional step is required to separate the catalyst with treated water. In the HPMR system, even though the RB5 photocatalytic degradation exhibits lower efficiency however the rejection of RB5 was achieved up to 95% under UV irradiation due to the properties of photocatalytic membranes. The well dispersed of TCP at the outer layer of DLHF membrane have improved the surface affinity of DL-TCP membrane towards water, exhibit the highest pure water flux of 41.72 L/m2.h compared to DL-TiO2 membrane. In general, CP can help on improving photocatalytic activity of TiO2 in suspension, increased the RB5 removal and the permeability of DLHF membrane in HPMR system as well.
    Matched MeSH terms: Ultraviolet Rays*
  13. Alias NH, Jaafar J, Samitsu S, Yusof N, Othman MHD, Rahman MA, et al.
    Chemosphere, 2018 Aug;204:79-86.
    PMID: 29653325 DOI: 10.1016/j.chemosphere.2018.04.033
    Separation and purification of oilfield produced water (OPW) is a major environmental challenge due to the co-production of the OPW during petroleum exploration and production operations. Effective capture of oil contaminant and its in-situ photodegradation is one of the promising methods to purify the OPW. Based on the photocatalytic capability of graphitic carbon nitride (GCN) which was recently rediscovered, photodegradation capability of GCN for OPW was investigated in this study. GCN was synthesized by calcination of urea and further exfoliated into nanosheets. The GCNs were incorporated into polyacrylonitrile nanofibers using electrospinning, which gave a liquid-permeable self-supporting photocatalytic nanofiber mat that can be handled by hand. The photocatalytic nanofiber demonstrated 85.4% degradation of OPW under visible light irradiation, and improved the degradation to 96.6% under UV light. Effective photodegradation of the photocatalytic nanofiber for OPW originates from synergetic effects of oil adsorption by PAN nanofibers and oil photodegradation by GCNs. This study provides an insight for industrial application on purification of OPW through photocatalytic degradation under solar irradiation.
    Matched MeSH terms: Ultraviolet Rays
  14. Nordin N, Ho LN, Ong SA, Ibrahim AH, Lee SL, Ong YP
    Chemosphere, 2019 Jan;214:614-622.
    PMID: 30292044 DOI: 10.1016/j.chemosphere.2018.09.144
    The hybrid system of photocatalytic fuel cell - peroxi-coagulation (PFC-PC) is a sustainable and green technology to degrade organic pollutants and generate electricity simultaneously. In this study, three different types of photocatalysts: TiO2, ZnO and α-Fe2O3 were immobilized respectively on carbon cloth (CC), and applied as photoanodes in the photocatalytic fuel cell of this hybrid system. Photocatalytic fuel cell was employed to drive a peroxi-coagulation process by generating the external voltage accompanying with degrading organic pollutants under UV light irradiation. The degradation efficiency of Amaranth dye and power output in the hybrid system of PFC-PC were evaluated by applying different photoanode materials fabricated in this study. In addition, the effect of light on the photocurrent of three different photoanode materials was investigated. In the absence of light, the reduction of photocurrent percentage was found to be 69.7%, 17.3% and 93.2% in TiO2/CC, ZnO/CC and α-Fe2O3/CC photoanodes, respectively. A maximum power density (1.17 mWcm-2) and degradation of dye (93.8%) at PFC reactor were achieved by using ZnO/CC as photoanode. However, the different photoanode materials at PFC showed insignificant difference in dye degradation trend in the PC reactor. Meanwhile, the degradation trend of Amaranth at PFC reactor was influenced by the recombination rate, electron mobility and band gap energy of photocatalyst among different photoanode materials.
    Matched MeSH terms: Ultraviolet Rays
  15. Lee SL, Ho LN, Ong SA, Wong YS, Voon CH, Khalik WF, et al.
    Chemosphere, 2018 Oct;209:935-943.
    PMID: 30114743 DOI: 10.1016/j.chemosphere.2018.06.157
    Reactive green 19, acid orange 7 and methylene blue are employed as the organic pollutants in this work. A photocatalytic fuel cell is constructed based on the idea of immobilizing zinc oxide onto zinc photoanode and platinum loaded carbon cathode, both evaluated under sunlight and ultraviolet irradiation, respectively. Influence of light and dye structures on the performance of photocatalytic fuel cell are examined. With reactive green 19, 93% and 86% of color removal are achieved after 8 h of photocatalytic fuel cell treatment under sunlight and ultraviolet irradiation, respectively. The decolorization rate of diazo reactive green 19 is higher than acid orange 7 (monoazo dye) when both dyes are treated by photocatalytic fuel cell under sunlight and ultraviolet irradiation, as the electron releasing groups (-NH-triazine) allow reactive green 19 easier to be oxidized. Comparatively, acid orange 7 is less favorable to be oxidized. The degradation of methylene blue is enhanced under sunlight irradiation due to the occurrence of self-sensitized photodegradation. When methylene blue is employed in the photocatalytic fuel cell under sunlight irradiation, the short circuit current (0.0129 mA cm-2) and maximum power density (0.0032 mW cm-2) of photocatalytic fuel cell greatly improved.
    Matched MeSH terms: Ultraviolet Rays
  16. Nordin N, Ho LN, Ong SA, Ibrahim AH, Abdul Rani AL, Lee SL, et al.
    Chemosphere, 2020 Apr;244:125459.
    PMID: 31790991 DOI: 10.1016/j.chemosphere.2019.125459
    The hybrid electrochemical system of photocatalytic fuel cell - peroxi-coagulation (PFC-PC) is a combined technology of advanced oxidation process (AOP) which involve the hydroxyl radical formation for simultaneous degradation of organic pollutant and electricity generation. The p-nitrosodimethylaniline (RNO) spin trapping technique was applied by analyzing the RNO bleaching performance to detect the OH at the PFC and PC reactors. The presence of UV light showed higher RNO bleaching rate at the PFC reactor (11.7%) with maximum power density (Pmax = 3.14 mW cm-2). Results revealed that the optimum of maximum power density was observed at iron plate size of 30 cm2. UV light became a limiting factor in the PFC system as a power source in the PFC-PC system. Meanwhile, iron plate plays an important role to supply the soluble Fe2+ ions by oxidation process and become a suitable catalyst for in-situ production of H2O2 and OH through the PC process to degrade the organic molecules.
    Matched MeSH terms: Ultraviolet Rays
  17. Li B, Amin AH, Ali AM, Isam M, Lagum AA, Sabugaa MM, et al.
    Chemosphere, 2023 Sep;336:139208.
    PMID: 37321458 DOI: 10.1016/j.chemosphere.2023.139208
    UV and solar-based photocatalytic degradation of 2,4-dichlorophenol (2,4-DCP) as an organic contaminant in ceramics industry wastewater by ZnS and Fe-doped ZnS NPs was the focus of this research. Nanoparticles were prepared using a chemical precipitation process. The cubic, closed-packed structure of undoped ZnS and Fe-doped ZnS NPs was formed in spherical clusters, according to XRD and SEM investigations. According to optical studies, the optical band gaps of pure ZnS and Fe-doped ZnS nanoparticles are 3.35 and 2.51 eV, respectively, and Fe doping increased the number of carriers with high mobility, improved carrier separation and injection efficiency, and increased photocatalytic activity under UV or visible light. Doping of Fe increased the separation of photogenerated electrons and holes and facilitated charge transfer, according to electrochemical impedance spectroscopy investigations. Photocatalytic degradation studies revealed that in the present pure ZnS and Fe-doped ZnS nanoparticles, 100% treatment of 120 mL of 15 mg/L phenolic compound was obtained after 55- and 45-min UV-irradiation, respectively, and complete treatment was attained after 45 and 35-min solar light irradiation, respectively. Because of the synergistic effects of effective surface area, more effective photo-generated electron and hole separation efficiency, and enhanced electron transfer, Fe-doped ZnS demonstrated high photocatalytic degradation performance. The study of Fe-doped ZnS's practical photocatalytic treatment capability for removing 120 mL of 10 mg/L 2,4-DCP solution made from genuine ceramic industrial wastewater revealed Fe-doped ZnS's excellent photocatalytic destruction of 2,4-DCP from real industrial wastewater.
    Matched MeSH terms: Ultraviolet Rays
  18. Tan EW, Simon SE, Numan A, Khalid M, Tan KO
    Colloids Surf B Biointerfaces, 2024 Mar;235:113793.
    PMID: 38364521 DOI: 10.1016/j.colsurfb.2024.113793
    Breast cancer is a global health concern that requires personalized therapies to prevent relapses, as conventional treatments may develop resistance over time. Photothermal therapy using spectral radiation or intense light emission is a broad-spectrum treatment that induces hyperthermia-mediated cancer cell death. MXene, a two-dimensional material, has been reported to have potential biological applications in photothermal therapy for cancer treatment. In this study, we investigated the apoptotic activity of MXene and UV-irradiated MXene in MCF-7 breast cancer cells by treating them with varying concentrations of MXene. The cytotoxicity of MXene and UV was evaluated by analyzing cellular morphology, nuclei condensation, caspase activation, and apoptotic cell death. We also assessed the effect of the combined treatment on the expression and cellular distribution of Tubulin, a key component of microtubules required for cell division. At low concentrations of MXene (up to 100 µg/ml), the level of cytotoxicity in MCF-7 cells was low. However, the combined treatment of MXene and UV resulted in a synergistic increase in cytotoxicity, causing rounded cellular morphology, condensed nuclei, caspase activation, and apoptotic cell death. Furthermore, the treatment reduced Tubulin protein expression and cellular distribution, indicating a potent inducer of cell death with potential application for cancer treatment. The study demonstrates that the combined treatment of MXene and UVB irradiation is a promising strategy for inducing apoptotic cell death in breast cancer cells, suggesting its potential as a therapeutic intervention for breast cancer.
    Matched MeSH terms: Ultraviolet Rays*
  19. Zhan SZ, Chen W, Zheng J, Ng SW, Li D
    Dalton Trans, 2021 Jan 18.
    PMID: 33459321 DOI: 10.1039/d0dt03661g
    Five luminescent polymorphic aggregates of trinuclear Cu(i)-pyrazolate, namely [anti-Cu3L3]2 (1), [syn-Cu3L3·C2H5OH]2 (2), [anti-Cu3L3·C2H5OH]n (3), [anti-Cu3L3·0.5C7H8]n (4) and [syn-Cu3L3·C8H10]n (5) (HL = 4-(pyridin-4-ylthio)-3,5-dimethyl-1H-pyrazole), were reported. The trimeric Cu3L3 fragments present syn- and anti-conformations dependent on the dangled direction of 4-pyridyl groups on the two sides of the Cu3Pz3 plane (Pz = pyrazolate). Intertrimeric NPyCu weak coordination bonds associate these Cu3L3 fragments together to form dimeric or polymeric structures, which are further stabilized by crystallized solvent molecules or intertrimeric CuCu interactions. The solvated complexes (3-5) may be transformed into the unsolvated complex 1 by evacuation of the crystallized solvents upon heating. All these complexes emit from green to yellow under UV irradiation, which originated from the triplet excited states of metal to ligand charge transfer (3MLCT) mixed with intertrimeric CuCu interactions. This work provides a novel kind of supramolecular aggregate based on Cu3Pz3 beyond the classical π-acidbase adducts and metallophilicity-dependent dimers/oligomers.
    Matched MeSH terms: Ultraviolet Rays
  20. Valappil NKM, Mammen PC, de Oliveira-Júnior JF, Cardoso KRA, Hamza V
    Environ Monit Assess, 2024 Jan 03;196(2):106.
    PMID: 38168710 DOI: 10.1007/s10661-023-12239-w
    The spatial and temporal dynamics of daily ultraviolet index (UVI) for a period of 18 years (2004-2022) over the Indian state of Kerala were statistically characterised in the study. The UVI measurements used for the study were derived from the ultraviolet-B (UVB) irradiance measured by the Ozone Monitoring Instrument (OMI) of the AURA satellite and classified into different severity levels for analysis. Basic statistics of daily, monthly and seasonal UVI as well as Mann-Kendall (MK) statistical trend characteristics and the rate of change of daily UVI using Theil-Sen's slope test were also evaluated. A higher variability of UVI characteristics was observed in the Kerala region, and more than 79% of the measurements fell into the categories of very high and extreme UVI values, which suggests the need of implementation of appropriate measures to reduce health risks. Although the UVI measured during the study period shows a slight decrease, most of the data show a seasonal variation with undulating low and peak values. Higher UVI are observed during the months of March, April and September. The region also has higher UVI during the southwest monsoon (SWM) and summer seasons. Although Kerala region as a single whole unit, UVI show a non-significant decreasing trend (-0.83), the MK test revealed the increasing and decreasing trends of UVI ranging from -1.96 to 0.41 facilitated the delineation of areas (domains) where UVI are increasing or decreasing. The domain of UVI increase occupies the central and southern (S) parts, and the domains of decrease cover the northern (N) and S parts of the Kerala region. The rate of change of daily UVI in domain of increase and decrease shows an average rate of 0.34 × 10-5 day-1 and -2 × 10-5 day-1, respectively. The parameters (rainfall, air temperature, cloud optical depth (COD) and solar zenith angle (SZA)) that affect the strength of UV rays reaching the surface indicate that a cloud-free atmosphere or low thickness clouds prevails in the Kerala region. Overall, the study results indicate the need for regular monitoring of UVI in the study area and also suggest appropriate campaigns to disseminate information and precautions for prolonged UVI exposure to reduce the adverse health effects, since the study area has a high population density.
    Matched MeSH terms: Ultraviolet Rays
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