Displaying publications 101 - 120 of 335 in total

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  1. Microleakage assessment of a repaired, nano-filled, resin-based fissure sealant
    Qadri GW, Noor SN, Mohamad D
    Pediatr Dent, 2009 Sep-Oct;31(5):389-94.
    PMID: 19947133
    The purpose of this study was to evaluate the effects of different repairing techniques of a fractured sealant on microleakage in vitro.
    Matched MeSH terms: Light-Curing of Dental Adhesives
  2. Changes in photosynthesis and leaf characteristics with tree height in five dipterocarp species in a tropical rain forest
    Kenzo T, Ichie T, Watanabe Y, Yoneda R, Ninomiya I, Koike T
    Tree Physiol, 2006 Jul;26(7):865-73.
    PMID: 16585032
    Variations in leaf photosynthetic, morphological and biochemical properties with increasing plant height from seedlings to emergent trees were investigated in five dipterocarp species in a Malaysian tropical rain forest. Canopy openness increased significantly with tree height. Photosynthetic properties, such as photosynthetic capacity at light saturation, light compensation point, maximum rate of carboxylation and maximum rate of photosynthetic electron transport, all increased significantly with tree height. Leaf morphological and biochemical traits, such as leaf mass per area, palisade layer thickness, nitrogen concentration per unit area, chlorophyll concentration per unit dry mass and chlorophyll to nitrogen ratio, also changed significantly with tree height. Leaf properties had simple and significant relationships with tree height, with few intra- and interspecies differences. Our results therefore suggest that the photosynthetic capacity of dipterocarp trees depends on tree height, and that the trees adapt to the light environment by adjusting their leaf morphological and biochemical properties. These results should aid in developing models that can accurately estimate carbon dioxide flux and biomass production in tropical rain forests.
    Matched MeSH terms: Light
  3. Fulltext Suboptimal Acclimation of Photosynthesis to Light in Wheat Canopies
    Townsend AJ, Retkute R, Chinnathambi K, Randall JWP, Foulkes J, Carmo-Silva E, et al.
    Plant Physiol, 2018 Feb;176(2):1233-1246.
    PMID: 29217593 DOI: 10.1104/pp.17.01213
    Photosynthetic acclimation (photoacclimation) is the process whereby leaves alter their morphology and/or biochemistry to optimize photosynthetic efficiency and productivity according to long-term changes in the light environment. The three-dimensional architecture of plant canopies imposes complex light dynamics, but the drivers for photoacclimation in such fluctuating environments are poorly understood. A technique for high-resolution three-dimensional reconstruction was combined with ray tracing to simulate a daily time course of radiation profiles for architecturally contrasting field-grown wheat (Triticum aestivum) canopies. An empirical model of photoacclimation was adapted to predict the optimal distribution of photosynthesis according to the fluctuating light patterns throughout the canopies. While the photoacclimation model output showed good correlation with field-measured gas-exchange data at the top of the canopy, it predicted a lower optimal light-saturated rate of photosynthesis at the base. Leaf Rubisco and protein contents were consistent with the measured optimal light-saturated rate of photosynthesis. We conclude that, although the photosynthetic capacity of leaves is high enough to exploit brief periods of high light within the canopy (particularly toward the base), the frequency and duration of such sunflecks are too small to make acclimation a viable strategy in terms of carbon gain. This suboptimal acclimation renders a large portion of residual photosynthetic capacity unused and reduces photosynthetic nitrogen use efficiency at the canopy level, with further implications for photosynthetic productivity. It is argued that (1) this represents an untapped source of photosynthetic potential and (2) canopy nitrogen could be lowered with no detriment to carbon gain or grain protein content.
    Matched MeSH terms: Light
  4. In vitro Study of SPIONs-C595 as Molecular Imaging Probe for Specific Breast Cancer (MCF-7) Cells Detection
    Moradi Khaniabadi P, Shahbazi-Gahrouei D, Malik Shah Abdul Majid A, Suhaimi Jaafar M, Moradi Khaniabadi B, Shahbazi-Gahrouei S
    Iran Biomed J, 2017 11;21(6):360-8.
    PMID: 28601058
    Background: Magnetic resonance imaging (MRI) plays an essential role in molecular imaging by delivering the contrast agent into targeted cancer cells. The aim of this study was to evaluate the C595 monoclonal antibody-conjugated superparamagnetic iron oxide nanoparticles (SPIONs-C595) for the detection of breast cancer cell (MCF-7).

    Methods: The conjugation of monoclonal antibody and nanoparticles was confirmed using X-ray diffraction, transmission electron microscopy, and photon correlation spectroscopy. The selectivity of the nanoprobe for breast cancer cells (MCF-7) was obtained by Prussian blue, atomic emission spectroscopy, and
    MRI relaxometry.

    Results: The in vitro MRI showed that T2 relaxation time will be reduced 76% when using T2-weighed magnetic resonance images compared to the control group (untreated cells) at the dose of 200 μg
    Fe/ml, as the optimum dose. In addition, the results showed the high uptake of nanoprobe into MCF-7
    cancer cells.

    Conclusion: The SPIONs-C595 nanoprobe has potential for the detection of specific breast cancer.

    Matched MeSH terms: Dynamic Light Scattering
  5. Effect of a single dose of low-level laser therapy on spontaneous and chewing pain caused by elastomeric separators
    Qamruddin I, Alam MK, Fida M, Khan AG
    Am J Orthod Dentofacial Orthop, 2016 Jan;149(1):62-6.
    PMID: 26718379 DOI: 10.1016/j.ajodo.2015.06.024
    The aim of this study was to see the effect of a single dose of low-level laser therapy on spontaneous and chewing pain after the placement of elastomeric separators.
    Matched MeSH terms: Low-Level Light Therapy/methods*
  6. Fulltext Photocatalysis and photoelectrochemical properties of tungsten trioxide nanostructured films
    Lai CW
    ScientificWorldJournal, 2014;2014:843587.
    PMID: 24782669 DOI: 10.1155/2014/843587
    Tungsten trioxide (WO₃) possesses a small band gap energy of 2.4-2.8 eV and is responsive to both ultraviolet and visible light irradiation including strong absorption of the solar spectrum and stable physicochemical properties. Thus, controlled growth of one-dimensional (1D) WO₃ nanotubular structures with desired length, diameter, and wall thickness has gained significant interest. In the present study, 1D WO₃ nanotubes were successfully synthesized via electrochemical anodization of tungsten (W) foil in an electrolyte composed of 1 M of sodium sulphate (Na₂SO₄) and ammonium fluoride (NH₄F). The influence of NH₄F content on the formation mechanism of anodic WO₃ nanotubular structure was investigated in detail. An optimization of fluoride ions played a critical role in controlling the chemical dissolution reaction in the interface of W/WO₃. Based on the results obtained, a minimum of 0.7 wt% of NH₄F content was required for completing transformation from W foil to WO₃ nanotubular structure with an average diameter of 85 nm and length of 250 nm within 15 min of anodization time. In this case, high aspect ratio of WO₃ nanotubular structure is preferred because larger active surface area will be provided for better photocatalytic and photoelectrochemical (PEC) reactions.
    Matched MeSH terms: Light*
  7. Shear bond strengths of buccal tubes
    Purmal K, Sukumaran P
    Aust Orthod J, 2010 Nov;26(2):184-8.
    PMID: 21175030
    To investigate the shear bond strengths of buccal tubes and to determine the sites of failure.
    Matched MeSH terms: Light-Curing of Dental Adhesives*
  8. Phage display of recombinant antibodies toward Burkholderia pseudomallei exotoxin
    Nathan S, Li H, Mohamed R, Embi N
    J. Biochem. Mol. Biol. Biophys., 2002 Feb;6(1):45-53.
    PMID: 12186782
    We have used the phagemid pComb3H to construct recombinant phages displaying the single chain variable fragment (ScFv) towards exotoxin of Burkholderia pseudomallei. Variable heavy and light chain fragments were amplified from the hybridoma 6E6A8F3B line, with a wide spectrum of primers specific to mouse antibody genes. Through overlapping extension polymerase chain reaction, the heavy and light chain fragments were linked to form the ScFv which was subsequently cloned into the phage display vector and transformed into ER2537 cells to yield a complexity of 10(8) clones. The transformants were screened by four rounds of biopanning against the exotoxin and resulted in selective enrichment of exotoxin-binding antibodies by 301 fold. The phage pool from the final round of selection displayed antibodies of high-affinity to the exotoxin as demonstrated by ELISA. Several clones were selected randomly from this pool and analysed by restriction enzyme digestion, fingerprinting and sequencing. Restriction analysis confirmed that all clones carried a 700-800 bp insert whose sequences, in general, corresponded to that of mouse IgG. Fingerprinting profiles delineated the antibodies into two families with different CDR sequences.
    Matched MeSH terms: Immunoglobulin Light Chains/genetics
  9. Asiatic acid stabilizes cytoskeletal proteins and prevents TNF-α-induced disorganization of cell-cell junctions in human aortic endothelial cells
    Fong LY, Ng CT, Yong YK, Hakim MN, Ahmad Z
    Vascul. Pharmacol., 2019 06;117:15-26.
    PMID: 30114509 DOI: 10.1016/j.vph.2018.08.005
    Endothelial hyperpermeability represents an initiating step in early atherosclerosis and it often occurs as a result of endothelial barrier dysfunction. Asiatic acid, a major triterpene isolated from Centella asiatica (L.) Urban, has previously been demonstrated to protect against tumor necrosis factor (TNF)-α-induced endothelial barrier dysfunction. The present study aimed to investigate the mechanisms underlying the barrier protective effect of asiatic acid in human aortic endothelial cells (HAECs). The localization of F-actin, diphosphorylated myosin light chain (diphospho-MLC), adherens junctions (AJs) and tight junctions (TJs) was studied using immunocytochemistry techniques and confocal microscopy. Their total protein expressions were examined using western blot analysis. The endothelial permeability was assessed using In Vitro Vascular Permeability Assay kits. In addition, intracellular redistribution of the junctional proteins was evaluated using subcellular fractionation kits. We show that asiatic acid stabilized F-actin and diphospho-MLC at the cell periphery and prevented their rearrangement stimulated by TNF-α. However, asiatic acid failed to attenuate cytochalasin D-induced increased permeability. Besides, asiatic acid abrogated TNF-α-induced structural reorganization of vascular endothelial (VE)-cadherin and β-catenin by preserving their reticulum structures at cell-cell contact areas. In addition, asiatic acid also inhibited TNF-α-induced redistribution of occludin and zona occludens (ZO)-1 in different subcellular fractions. In conclusion, the barrier-stabilizing effect of asiatic acid might be associated with preservation of AJs and prevention of TJ redistribution caused by TNF-α. This study provides evidence to support the potential use of asiatic acid in the prevention of early atherosclerosis, which is initiated by endothelial barrier dysfunction.
    Matched MeSH terms: Myosin Light Chains/metabolism
  10. Experimental infection of brown-marbled grouper, Epinephelus fuscoguttatus (Forskal), with Vibrio parahaemolyticus identifies parvalbumin beta-2 subunit I, alpha-2-macroglobulin, nattectin and immunoglobulin light chain, differentially expressed in resistant grouper
    Low CF, Shamsudin MN, Abdullah M, Chee HY, Aliyu-Paiko M
    J Fish Dis, 2015 Jan;38(1):17-25.
    PMID: 24397626 DOI: 10.1111/jfd.12195
    The mechanisms through which brown-marbled grouper accomplishes resistance to infection, particularly against Vibrios, are not yet fully understood. In this study, brown-marbled grouper fingerlings were experimentally infected with Vibrio parahaemolyticus, to identify disease resistance grouper, and the serum proteome profiles were compared between resistant and susceptible candidates, via two-dimensional gel electrophoresis (2-DE). The results showed that putative parvalbumin beta-2 subunit I, alpha-2-macroglobulin, nattectin and immunoglobulin light chain proteins were among proteins that significantly overexpressed in the resistant fish as compared to the susceptible group of fish, whereas apolipoprotein E and immunoglobulin light chain proteins were observed to be differentially overexpressed in the susceptible fish. Further analysis by peptide sequencing revealed that the immunoglobulin light chain proteins identified in the resistant and susceptible groups differed in amino acid composition. Taken together, the results demonstrated for the first time that putative parvalbumin beta-2 subunit I, alpha-2-macroglobulin, nattectin and immunoglobulin light chain are among important proteins participating to effect disease resistance mechanism in fish and were overexpressed to function collectively to resist V. parahaemolyticus infection. Most of these molecules are mediators of immune response.
    Matched MeSH terms: Immunoglobulin Light Chains/genetics
  11. The effectiveness of transmeatal low-power laser stimulation in treating tinnitus
    Ngao CF, Tan TS, Narayanan P, Raman R
    Eur Arch Otorhinolaryngol, 2014 May;271(5):975-80.
    PMID: 23605244 DOI: 10.1007/s00405-013-2491-3
    The aim of this study is to examine the effectiveness of transmeatal low-power laser stimulation (TLLS) in treating tinnitus. This is a prospective, double-blinded, randomized, placebo-controlled trial. Patients with persistent subjective tinnitus as their main symptom were recruited into the study from the outpatient clinics. The recruited patients were randomized into the experimental group or TLLS+ group (patients in this group were prescribed to use TLLS at 5 mW at 650 nM wavelength for 20 min daily and oral betahistine 24 mg twice per day for a total of 10 weeks) and the control group or TLLS- group (patients in this group were prescribed with a placebo device to use and oral betahistine 24 mg twice per day for 10 weeks). All patients were required to answer two sets of questionnaires: the Tinnitus handicap inventory (THI) and visual analogue scales (VAS) symptoms rating scales, before starting the treatment and at the end of the 10-week treatment period. The total score of the THI questionnaire was further graded into five grades, grade 1 being mild and grade 5 being catastrophic. Wilcoxon-signed ranks test and Mann-Whitney test were used to compare and analyze the THI and VAS scores before and after treatment for each group. Changes with p value of <0.05 were considered as statistically significant. Chi square test was used to analyze the change of parameters in categorical forms (to compare between TLLS+ and TLLS-). Changes with p value of <0.05 were considered as statistically significant. Forty-three patients successfully and diligently completed their treatment. It was noted that using any condition of the device, TLLS+ or TLLS-, patient's tinnitus symptoms improved in terms of THI scores (TLLS+, p value = 0.038; TLLS-, p value = 0.001) or VAS scores with a change of at least one grade (TLLS+, p value = 0.007; TLLS-, p value = 0.002) at p value <0.05 significant level. In contrast when TLLS+ group was compared with TLLS- group, no statistically significant result was obtained. In term of VAS scores, there seems to be no statistically significant improvement in patients' annoyance, sleep disruption, depression, concentration and tinnitus loudness and pitch heard between the two groups. Transmeatal low-power laser stimulation did not demonstrate significant efficacy as a therapeutic measure in treating tinnitus.
    Study site: Otorhinolaryngology clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
    Matched MeSH terms: Low-Level Light Therapy/instrumentation*
  12. Fulltext Cadmium Sulphide-Reduced Graphene Oxide-Modified Photoelectrode-Based Photoelectrochemical Sensing Platform for Copper(II) Ions
    Ibrahim I, Lim HN, Huang NM, Pandikumar A
    PLoS One, 2016;11(5):e0154557.
    PMID: 27176635 DOI: 10.1371/journal.pone.0154557
    A photoelectrochemical (PEC) sensor with excellent sensitivity and detection toward copper (II) ions (Cu2+) was developed using a cadmium sulphide-reduced graphene oxide (CdS-rGO) nanocomposite on an indium tin oxide (ITO) surface, with triethanolamine (TEA) used as the sacrificial electron donor. The CdS nanoparticles were initially synthesized via the aerosol-assisted chemical vapor deposition (AACVD) method using cadmium acetate and thiourea as the precursors to Cd2+ and S2-, respectively. Graphene oxide (GO) was then dip-coated onto the CdS electrode and sintered under an argon gas flow (50 mL/min) for the reduction process. The nanostructured CdS was adhered securely to the ITO by a continuous network of rGO that also acted as an avenue to intensify the transfer of electrons from the conduction band of CdS. The photoelectrochemical results indicated that the ITO/CdS-rGO photoelectrode could facilitate broad UV-visible light absorption, which would lead to a higher and steady-state photocurrent response in the presence of TEA in 0.1 M KCl. The photocurrent decreased with an increase in the concentration of Cu2+ ions. The photoelectrode response for Cu2+ ion detection had a linear range of 0.5-120 μM, with a limit of detection (LoD) of 16 nM. The proposed PEC sensor displayed ultra-sensitivity and good selectivity toward Cu2+ ion detection.
    Matched MeSH terms: Light*
  13. Hyperexcretion of homocitrulline in a Malaysian patient with lysinuric protein intolerance
    Habib A, Md Yunus Z, Azize NA, Ch'ng GS, Ong WP, Chen BC, et al.
    Eur J Pediatr, 2013 Sep;172(9):1277-81.
    PMID: 23358709 DOI: 10.1007/s00431-013-1947-1
    Lysinuric protein intolerance (LPI; MIM 222700) is an inherited aminoaciduria with an autosomal recessive mode of inheritance. Biochemically, affected patients present with increased excretion of the cationic amino acids: lysine, arginine, and ornithine. We report the first case of LPI diagnosed in Malaysia presented with excessive excretion of homocitrulline. The patient was a 4-year-old male who presented with delayed milestones, recurrent diarrhea, and severe failure to thrive. He developed hyperammonemic coma following a forced protein-rich diet. Plasma amino acid analysis showed increased glutamine, alanine, and citrulline but decreased lysine, arginine and ornithine. Urine amino acids showed a marked excretion of lysine and ornithine together with a large peak of unknown metabolite which was subsequently identified as homocitrulline by tandem mass spectrometry. Molecular analysis confirmed a previously unreported homozygous mutation at exon 1 (235 G > A, p.Gly79Arg) in the SLC7A7 gene. This report demonstrates a novel mutation in the SLC7A7 gene in this rare inborn error of diamino acid metabolism. It also highlights the importance of early and efficient treatment of infections and dehydration in these patients.

    CONCLUSION: The diagnosis of LPI is usually not suspected by clinical findings alone, and specific laboratory investigations and molecular analysis are important to get a definitive diagnosis.

    Matched MeSH terms: Antigens, CD98 Light Chains/genetics*
  14. Fulltext Phyto-Mediated Photo Catalysed Green Synthesis of Silver Nanoparticles Using Durio Zibethinus Seed Extract: Antimicrobial and Cytotoxic Activity and Photocatalytic Applications
    Sumitha S, Vasanthi S, Shalini S, Chinni SV, Gopinath SCB, Anbu P, et al.
    Molecules, 2018 Dec 13;23(12).
    PMID: 30551671 DOI: 10.3390/molecules23123311
    In the present study, we have developed a green approach for the synthesis of silver nanoparticles (DSAgNPs) using aqueous extract of Durio zibethinus seed and determined its antibacterial, photocatalytic and cytotoxic effects. Surface plasmon resonance confirmed the formation of DSAgNPs with a maximum absorbance (λmax) of 420 nm. SEM and TEM images revealed DSAgNPs were spherical and rod shaped, with a size range of 20 nm and 75 nm. The zeta potential was found to be -15.41 mV. XRD and EDX analyses confirmed the nature and presence of Ag and AgCl. DSAgNPs showed considerable antibacterial activity, exhibited better cytotoxicity against brine shrimp, and shown better photocatalytic activity against methylene blue. Based on the present research work, it can be concluded that DSAgNPs could be used in the field of water treatment, pharmaceuticals, biomedicine, biosensor and nanotechnology in near future.
    Matched MeSH terms: Light*
  15. Proton-Functionalized Graphitic Carbon Nitride for Efficient Metal-Free Destruction of Escherichia coli under Low-Power Light Irradiation
    Ng BJ, Musyaffa MK, Er CC, Packiam KAR, Lee WPC, Tan LL, et al.
    Chemistry, 2021 Feb 10;27(9):3085-3090.
    PMID: 33263935 DOI: 10.1002/chem.202004238
    Universal access to clean water has been a global ambition over the years. Photocatalytic water disinfection through advanced oxidation processes has been regarded as one of the promising methods for breaking down microbials. The forefront of this research focuses on the application of metal-free photocatalysts for disinfection to prevent secondary pollution. Graphitic carbon nitride (g-C3 N4 ) has achieved instant attention as a metal-free and visible-light-responsive photocatalyst for various energy and environmental applications. However, the photocatalytic efficiency of g-C3 N4 is still affected by its rapid charge recombination and sluggish electron-transfer kinetics. In this contribution, two-dimensionally protonated g-C3 N4 was employed as metal-free photocatalyst for water treatment and demonstrated 100 % of Escherichia coli within 4 h under irradiation with a 23 W light bulb. The introduction of protonation can modulate the surface charge of g-C3 N4 ; this enhances its conductivity and provides a "highway" for the delocalization of electrons. This work highlights the potential of conjugated polymers in antibacterial application.
    Matched MeSH terms: Light*
  16. Selective and sensitive visible-light-prompt photoelectrochemical sensor of Cu2+ based on CdS nanorods modified with Au and graphene quantum dots
    Ibrahim I, Lim HN, Huang NM, Jiang ZT, Altarawneh M
    J Hazard Mater, 2020 06 05;391:122248.
    PMID: 32062348 DOI: 10.1016/j.jhazmat.2020.122248
    Nowadays, increasing the risk for copper leaching into the drinking water in homes, hotels and schools has become unresolved issues all around the countries such as Canada, the United States, and Malaysia. The leaching of copper in tap water is due to a combination of acidic water, damaged pipes, and corroded plumbing fixtures. To remedy this global problem, a triple interconnected structure of CdS/Au/GQDs was designed as a photo-to-electron conversion medium for a real time and selective visible-light-prompt photoelectrochemical (PEC) sensor for Cu2+ ions in real water samples. The synergistic interaction of the CdS/Au/GQDs enabled the smooth transportation of charge carriers to the charge collector and provided a channel to inhibit the charge recombination reaction. Thus, a detection limit of 2.27 nM was obtained, which is 10,000 fold lower than that of WHO's Guidelines for Drinking-water Quality (∼30 μM). The photocurrent reduction was negligible after 30 days of storage under ambient conditions, suggesting the high stability of photoelectrode. Moreover, the real-time monitoring of Cu2+ ions in real samples was performed with satisfactory results, confirming the capability of the investigated photoelectrode as the most practical detector for trace amounts of Cu2+ ions.
    Matched MeSH terms: Light*
  17. Photobiomodulation After Neurotization (Oberlin Procedure) in Brachial Plexus Injury: A Randomized Control Trial
    Foo YH, Tunku Ahmad Yahaya TS, Chung TY, Silvanathan JP
    Photobiomodul Photomed Laser Surg, 2020 Apr;38(4):215-221.
    PMID: 32301668 DOI: 10.1089/photob.2019.4757
    Objective:
    To investigate effect of photobiomodulation (PBM) on nerve regeneration after neurotization with the Oberlin Procedure (ulnar fascicle to motor branch to biceps) to restore elbow flexion in patients with brachial plexus injury.
    Materials and methods:
    This prospective randomized controlled trial was conducted with 14 patients with high brachial plexus injury who underwent neurotization with the Oberlin Procedure to restore elbow flexion. The patients were randomly allocated to two groups of equal numbers: control group and PBM group. In this study, the PBM used has a wavelength of 808 nm, 50 mW power, continuous mode emission, 4 J/cm2 dosimetry, administered daily for 10 consecutive days, with an interval of 2 days (weekends). The outcome of surgery was assessed after 1, 2, 3, and 6 months. The nonparametric Mann-Whitney U-test and chi-square test were utilized to compare the results between both groups.
    Results:
    After 3 months postoperatively, more patients in the PBM group had demonstrated signs of reinnervation and the mean muscle power was significantly higher in the PBM group. No adverse effects resulted from the administration of PBM.
    Conclusions:
    PBM is a treatment modality that can improve nerve regeneration after neurotization with the Oberlin Procedure.
    Matched MeSH terms: Low-Level Light Therapy*
  18. Photocatalytic magnetic separable beads for chromium (VI) reduction
    Idris A, Hassan N, Mohd Ismail NS, Misran E, Yusof NM, Ngomsik AF, et al.
    Water Res, 2010 Mar;44(6):1683-8.
    PMID: 19963234 DOI: 10.1016/j.watres.2009.11.026
    Magnetically separable photocatalyst beads containing nano-sized iron oxide in alginate polymer were prepared. This magnetic photocatalyst beads are used in slurry-type reactors. The magnetism of the catalyst arises from the nanostructured particles gamma-Fe(2)O(3), by which the catalyst can be easily recovered by the application of an external magnetic field. These synthesized beads are sunlight-driven photocatalyst. In the system without magnetic photocatalyst beads, no chromium reduction was observed under sunlight irradiation due to the stability of the chromium (VI). Upon the addition of magnetic photocatalyst beads, the photo-reduction of Cr(VI) was completed in just after only 50min under sunlight irradiation due to the photocatalytic activity of the beads. However when placed away from sunlight, the reduction rate of the chromium is just about 10%. These observations were explained in terms of absorption occurrence of chromium (VI) onto the catalyst surface which took place in this reaction. In addition, photo-reduction rate of chromium (VI) was more significant at lower pH. The results suggest that the use of magnetic separable photocatalyst beads is a feasible strategy for eliminating Cr(VI).
    Matched MeSH terms: Light*
  19. Influence of gold nanoparticles on wound healing treatment in rat model: Photobiomodulation therapy
    Lau P, Bidin N, Islam S, Shukri WNBWM, Zakaria N, Musa N, et al.
    Lasers Surg Med, 2017 04;49(4):380-386.
    PMID: 27859389 DOI: 10.1002/lsm.22614
    BACKGROUND AND OBJECTIVE: The aim of this study is to investigate the effect of gold nanoparticles (AuNPs) in photobiomodulation therapy (PBMT) on wound healing process.

    MATERIALS AND METHODS: AuNPs are synthesized by Q-switched Nd:YAG laser ablation technique. Cutaneous wound are induced on 45 Sprague Dawley rats on its dorsal part and then randomly divided into three groups. One group serves as non-treatment group (GC) and another two groups are subjected to AuNPs with and without PBMT. About 808 nm diode laser with output power of 100 mW is used as a light source for PBMT. The treatment was carried out daily with exposure duration of 50 seconds and total fluence of 5 J/cm2 . Wound area is monitored for 9 consecutive days using a digital camera, and histological examination is performed at 3rd, 6th, and 9th day through hematoxylin and eosin stain as well as Masson's trichrome stain.

    RESULTS: The group of rats subjected to AuNPs with PBMT shows significantly accelerated wound closure compared to other groups. Histological results indicate that AuNPs and PBMT group is more effective in stimulating angiogenesis and triggers inflammatory response at early stage.

    CONCLUSION: The application of AuNPs in PBMT has potential to accelerate wound healing due to enhanced epithelialization, collagen deposition and fast vascularization. Lasers Surg. Med. 49:380-386, 2017. © 2016 Wiley Periodicals, Inc.

    Matched MeSH terms: Low-Level Light Therapy/methods*
  20. Visible light responsive flower-like ZnO in photocatalytic antibacterial mechanism towards Enterococcus faecalis and Micrococcus luteus
    Quek JA, Lam SM, Sin JC, Mohamed AR
    J. Photochem. Photobiol. B, Biol., 2018 Oct;187:66-75.
    PMID: 30099271 DOI: 10.1016/j.jphotobiol.2018.07.030
    Flower-like ZnO micro/nanostructures were successfully fabricated via a surfactant-free co-precipitation method. The as-synthesized product was characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and photoluminescence (PL) analyses. In the presence of visible light irradiation, the as-synthesized flower-like ZnO showed higher antibacterial activities against Enterococcus faecalis (E. faecalis) and Micrococcus luteus (M. luteus) than that of commercial ZnO. The excellent antibacterial performance of synthesized flower-like ZnO was also observed via the bacterial morphological change, K+ ions leakage and protein leakage in extracellular suspension. In addition, the FTIR investigation on both treated bacteria further confirmed the bacterial membrane damage via cellular substance alteration. The enhancement of the antibacterial activity of synthesized ZnO can be attributed to the unique flower-like morphology which can increase the surface OH- groups and the quantity of photogenerated electron-hole pair available to participate in the photocatalytic reaction. The reactive oxidizing species (ROS) scavengers experiments showed that H2O2 played a main role in the photocatalytic antibacterial process. Our study showed that the synthesized flower-like ZnO micro/nanostructures can act as efficient antibacterial agents in the photocatalytic antibacterial process under visible light irradiation.
    Matched MeSH terms: Light*
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