Displaying publications 1 - 20 of 337 in total

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  1. Jaswir I, Shahidan N, Othman R, Has-Yun Hashim YZ, Octavianti F, bin Salleh MN
    J Oleo Sci, 2014;63(8):761-7.
    PMID: 25007748
    Carotenoids are antioxidants with pharmaceutical potential. The major carotenoids important to humans are α-carotene, β-carotene, lycopene, lutein, zeaxanthin, and β-cryptoxanthin. Some of the biological functions and actions of these individual carotenoids are quite similar to each other, whereas others are specific. Besides genotype and location, other environmental effects such as temperature, light, mineral uptake, and pH have been found affect carotenoid development in plant tissues and organs. Therefore, this research investigated the effects of the season and storage periods during postharvest handling on the accumulation of carotenoid in pumpkin. This study shows that long-term storage of pumpkins resulted in the accumulation of lutein and β-carotene with a slight decrease in zeaxanthin. The amounts of β-carotene ranged from 174.583±2.105 mg/100g to 692.871±22.019 mg/100g, lutein from 19.841±9.693 mg/100g to 59.481±1.645 mg/100g, and zeaxanthin from not detected to 2.709±0.118 mg/100g. The pumpkins were collected three times in a year; they differed in that zeaxanthin was present only in the first season, while the amounts of β-carotene and lutein were the highest in the second and third seasons, respectively. By identifying the key factors among the postharvest handling conditions that control specific carotenoid accumulations, a greater understanding of how to enhance the nutritional values of pumpkin and other crops will be gained. Postharvest storage conditions can markedly enhance and influence the levels of zeaxanthin, lutein, and β-carotene in pumpkin. This study describes how the magnitudes of these effects depend on the storage period and season.
    Matched MeSH terms: Light
  2. Razali WA, Sreenivasan VK, Bradac C, Connor M, Goldys EM, Zvyagin AV
    J Biophotonics, 2016 08;9(8):848-58.
    PMID: 27264934 DOI: 10.1002/jbio.201600050
    Fluorescence microscopy is a fundamental technique for the life sciences, where biocompatible and photostable photoluminescence probes in combination with fast and sensitive imaging systems are continually transforming this field. A wide-field time-gated photoluminescence microscopy system customised for ultrasensitive imaging of unique nanoruby probes with long photoluminescence lifetime is described. The detection sensitivity derived from the long photoluminescence lifetime of the nanoruby makes it possible to discriminate signals from unwanted autofluorescence background and laser backscatter by employing a time-gated image acquisition mode. This mode enabled several-fold improvement of the photoluminescence imaging contrast of discrete nanorubies dispersed on a coverslip. It enabled recovery of the photoluminescence signal emanating from discrete nanorubies when covered by a layer of an organic fluorescent dye, which were otherwise invisible without the use of spectral filtering approaches. Time-gated imaging also facilitated high sensitivity detection of nanorubies in a biological environment of cultured cells. Finally, we monitor the binding kinetics of nanorubies to a functionalised substrate, which exemplified a real-time assay in biological fluids. 3D-pseudo colour images of nanorubies immersed in a highly fluorescent dye solution. Nanoruby photoluminescence is subdued by that of the dye in continuous excitation/imaging (left), however it can be recovered by time-gated imaging (right). At the bottom is schematic diagram of nanoruby assay in a biological fluid.
    Matched MeSH terms: Light
  3. Nadia Yaacob, Adil Hussein, Maizan Yaakob, Zuraidah Mustari
    MyJurnal
    The presence of retinal vasculitis in patients with pulmonary tuberculosis is not uncommon. However, asymptomatic presentations are quite rare. Here, we present a case of 25-year-old Malay gentleman with pulmonary tuberculosis, who was referred for an eye assessment following initiation of anti-tuberculosis drugs. His vision was good; he had no other symptoms despite having retinal neovascularization, pre-retinal haemorrhages and healed choroiditis at the fundus of the left eye. Fundus fluorescein angiography showed multiple areas of capillary fallouts at the superotemporal quadrant of the left eye with leakage from the retinal neovascularization. He was treated with laser retinal photocoagulation and oral steroids for 6 weeks, while the anti-tuberculosis drugs were continued for 9 months. Subsequent follow-ups showed regression of the neovascularization. He has remained asymptomatic since his initial visit to the eye clinic.
    Matched MeSH terms: Light Coagulation
  4. Maryam S, Fadzly N, Amirul AA, Zuharah WF
    Rev Inst Med Trop Sao Paulo, 2017 Apr 03;59:e4.
    PMID: 28380115 DOI: 10.1590/S1678-9946201759004
    Paederus fuscipes, a vector of Paederus dermatitis in most tropical and subtropical countries of the world have a high prevalence in human dwellings due to their positively phototaxic behaviour which has caused a tremendous impact on human health. In this paper, P. fuscipes dispersal flights were studied for two seasons of the rice cultivation phases in residential premises built close to rice field areas (≈32-60 m and 164 m) in mainland Penang, Malaysia. We examined the effects of different light illuminance, building floor level and their association with rice stages as a focal cause of P. fuscipes dispersion from the rice fields towards human dwellings. The present study showed a significant interaction between different light illuminances and rice cultivation phases in attracting P. fuscipes to disperse and invade human dwellings. The highest number of P. fuscipes was captured near the bright light. P. fuscipes flights increased in line with each floor level, and the highest captures took place at higher building floor levels (levels 2 and 3) compared to lower building floor levels (ground floor and level 1) of a three storey apartment in both rice seasons. This finding not only conveys a better understanding on P. fuscipes dispersal pattern, but also draws public attention on the occurrence of dermatitis linearis caused by the Paederus beetles.
    Matched MeSH terms: Light
  5. Hu J, Lin S, Tan BK, Hamzah SS, Lin Y, Kong Z, et al.
    Food Res Int, 2018 09;111:265-271.
    PMID: 30007685 DOI: 10.1016/j.foodres.2018.05.042
    Burkholderia cepacia (B. cepacia) is an aerobic Gram-negative bacillus found in various aquatic environments and can cause food contamination. We investigated the photodynamic antibacterial effects of food additive curcumin combined with EDTA on B. cepacia. We found a ~4-log reduction in B. cepacia viability when photo-irradiated with curcumin at 50 μM by blue LED light (16 mW/cm2) for 30 min with 0.4% (w/v) EDTA. Moreover, the bacterial morphological alterations and the leakage of intracellular contents were observed after photodynamic treatment. There were also obvious genomic DNA cleavage and a general loss of bacterial proteins assigned to large-scale protein degradation after photodynamic inactivation treatment. Collectively, curcumin in combination with EDTA illuminated by blue LED is a potential candidate for photodynamic inactivation of B. cepacia.
    Matched MeSH terms: Light
  6. Mahdi, M.A., Md. Ali, M.I., Ahmad, A., Zamzuri, A.K.
    ASM Science Journal, 2008;2(2):123-127.
    MyJurnal
    In this paper a study on the wideband double-pass Raman fibre amplifier with mirror as the pump reflector is reported. The pump lights at 1435 nm and 1455 nm were launched in a co-directional manner with respect to the input signal. The double-pass direction of the signal was achieved through a fibre loop mirror constructed using an optical circulator. It was shown that multiple signal amplification was achieved without any disturbance of stimulated Brillouin scattering.
    Matched MeSH terms: Light
  7. Razali MH, Noor AFM, Yusoff M
    J Nanosci Nanotechnol, 2020 02 01;20(2):965-972.
    PMID: 31383093 DOI: 10.1166/jnn.2020.16944
    In this study, a series of copper-ion-doped titanium dioxide (Cu-ion-doped TiO₂) nanotubes (NTs) were synthesized via a hydrothermal method by the concentration variation of doped Cu ions (0.00, 0.50, 1.00, 2.50, and 5.00 mmol). In addition, the samples were characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), nitrogen gas adsorption measurements, and ultraviolet-visible (UV-Vis) diffuse-reflectance spectroscopy. The photocatalytic activity of the Cu-iondoped TiO₂ NTs was investigated for the degradation of methyl orange (MO) under sunlight. The results obtained from the structural and morphological studies revealed that, at low concentrations of Cu-doped TiO₂ NTs, Cu is incorporated into the interstitial positions of the TiO₂ lattice, affording a new phase of TiO₂ (hexagonal) instead of the anatase TiO₂ (tetragonal) observed for undoped TiO₂ NTs. EDX analysis confirmed the presence of Cu in the TiO₂-based photocatalyst. All of the investigated samples exhibited a hollow fibrous-like structure, indicative of an NT morphology. The inner and outer diameters of the NTs were 4 nm and 10 nm, respectively. The photocatalysts exhibited a large surface area due to the NT morphology and a type IV isotherm and H3 hysteresis, corresponding to the mesopores and slit-shaped pores. The Cu-ion-doped TiO₂ NTs were excited by sunlight because of their low bandgap energy; and after the incorporation of Cu ions into the interstitial positions of the TiO₂ lattice, the NTs exhibited high visible-light activity owing to the low bandgap.
    Matched MeSH terms: Light; Sunlight
  8. Jalil MA, Phelawan J, Aziz MS, Saktioto T, Ong CT, Yupapin PP
    Artif Cells Nanomed Biotechnol, 2013 Apr;41(2):92-7.
    PMID: 22991968 DOI: 10.3109/10731199.2012.700519
    Acne vulgaris is adebilitating dermatologic disease, and is conventionally treated by laser therapy using a microring resonator system. An evolving understanding of laser-tissue interactions involving Propioni bacterium acneproducing porphyrins, and the development of lasers to target the sebaceous glands, has led to the development of an escalating number of laser light for acne treatment. The results show that the full width at half maximum of the proposed laser pulse of 0.15 nm can be generated using a microring resonator system. The power of the laser is 200 W and the wavelength laser is 1,032 nm, which is proposed as a treatment of acne vulgaris diseases.
    Matched MeSH terms: Light; Low-Level Light Therapy/instrumentation*; Low-Level Light Therapy/methods*
  9. Jalil MA, Ong CT, Saktioto T, Daud S, Aziz MS, Yupapin PP
    Artif Cells Nanomed Biotechnol, 2013 Jun;41(3):152-8.
    PMID: 22947143 DOI: 10.3109/10731199.2012.700520
    A microring resonator (MRRs) system incorporated with a add/drop filter is proposed in which ultra-short single, multi-temporal, and spatial optical soliton pulses are simulated and used to kill abnormal cells, tumors, and cancer. Chaotic signals are generated by a bright soliton pulse within a nonlinear MRRs system. Gold nanoparticles and ultra-short femtosecond/picosecond laser pulses' interaction holds great interest in laser nanomedicine. By using appropriate soliton input power and MRRs parameters, desired spatial and temporal signals can be generated over the spectrum. Results show that short temporal and spatial solitons pulse with FWHM = 712 fs and FWHM = 17.5 pm could be generated. The add/drop filter system is used to generate the high-capacity, ultra-short soliton pulses in the range of nanometer/second and picometer/second.
    Matched MeSH terms: Low-Level Light Therapy/instrumentation*; Low-Level Light Therapy/methods
  10. Lee SC, Lintang HO, Yuliati L
    Chem Asian J, 2012 Sep;7(9):2139-44.
    PMID: 22733646 DOI: 10.1002/asia.201200383
    A urea precursor was used for the first time to prepare mesoporous carbon nitride (MCN) by a thermal polymerization process with silica nanospheres as a hard template. Although the prepared MCN samples have similar structures and optical properties, it was revealed that the specific surface area, pore-size distribution, and morphology of the MCN samples depend on the initial mass ratio of urea to silica. Compared to the bulk carbon nitride (BCN) that only gave 20% phenol removal (6 h of irradiation), the activities can be enhanced up to 74% on MCN samples for photocatalytic removal of phenol under visible-light irradiation. The highest conversion was obtained on MCN with an initial mass ratio of urea to silica of 5, which has high surface area of 191 m(2) g(-1) and a nanoporous structure with uniform pore-size distribution of 7 nm. In addition to the high activity, the MCN sample also showed high photocatalytic stability.
    Matched MeSH terms: Light
  11. Md Noh UK, Zahidin AZ, Yong TK
    Clin Pract, 2012 Mar 30;2(2):e54.
    PMID: 24765453 DOI: 10.4081/cp.2012.e54
    A 26-year-old woman with a recent flare-up of systemic lupus erythematosus presented with peripheral retinal hemorrhages at a routine check-up. She is on a tapering dose of immunosuppressive agents. Her visual acuity was good. Fluorescein angiogram revealed vasculitic changes with capillary non-perfusion areas. A few weeks later, she developed cerebral lupus with advanced lupus nephritis. Immunosuppressive therapy was restarted and panretinal photocoagulation was delivered. Her visual acuity remained stable, despite development of a cataract from prednisolone therapy.
    Matched MeSH terms: Light Coagulation
  12. Ong WJ, Tan LL, Chai SP, Yong ST
    Chem Commun (Camb), 2015 Jan 18;51(5):858-61.
    PMID: 25429376 DOI: 10.1039/c4cc08996k
    A facile one-pot impregnation-thermal reduction strategy was employed to fabricate sandwich-like graphene-g-C3N4 (GCN) nanocomposites using urea and graphene oxide as precursors. The GCN sample exhibited a slight red shift of the absorption band edge attributed to the formation of a C-O-C bond as a covalent cross linker between graphene and g-C3N4. The GCN sample demonstrated high visible-light photoactivity towards CO2 reduction under ambient conditions, exhibiting a 2.3-fold enhancement over pure g-C3N4. This was ascribed to the inhibition of electron-hole pair recombination by graphene, which increased the charge transfer.
    Matched MeSH terms: Light
  13. Azaman SNA, Wong DCJ, Tan SW, Yusoff FM, Nagao N, Yeap SK
    Sci Rep, 2020 10 15;10(1):17331.
    PMID: 33060668 DOI: 10.1038/s41598-020-74410-4
    Chlorella can produce an unusually wide range of metabolites under various nutrient availability, carbon source, and light availability. Glucose, an essential molecule for the growth of microorganisms, also contributes significantly to the metabolism of various metabolic compounds produced by Chlorella. In addition, manipulation of light intensity also induces the formation of secondary metabolites such as pigments, and carotenoids in Chlorella. This study will focus on the effect of glucose addition, and moderate light on the regulation of carotenoid, lipid, starch, and other key metabolic pathways in Chlorella sorokiniana. To gain knowledge about this, we performed transcriptome profiling on C. sorokiniana strain NIES-2168 in response to moderate light stress supplemented with glucose under mixotrophic conditions. A total of 60,982,352 raw paired-end (PE) reads 100 bp in length was obtained from both normal, and mixotrophic samples of C. sorokiniana. After pre-processing, 93.63% high-quality PE reads were obtained, and 18,310 predicted full-length transcripts were assembled. Differential gene expression showed that a total of 937, and 1124 genes were upregulated, and downregulated in mixotrophic samples, respectively. Transcriptome analysis revealed that the mixotrophic condition caused upregulation of genes involved in carotenoids production (specifically lutein biosynthesis), fatty acid biosynthesis, TAG accumulation, and the majority of the carbon fixation pathways. Conversely, starch biosynthesis, sucrose biosynthesis, and isoprenoid biosynthesis were downregulated. Novel insights into the pathways that link the enhanced production of valuable metabolites (such as carotenoids in C. sorokiniana) grown under mixotrophic conditions is presented.
    Matched MeSH terms: Light*
  14. Yeang HY
    Bioessays, 2009 Nov;31(11):1211-8.
    PMID: 19795408 DOI: 10.1002/bies.200900078
    The plant maintains a 24-h circadian cycle that controls the sequential activation of many physiological and developmental functions. There is empirical evidence suggesting that two types of circadian rhythms exist. Some plant rhythms appear to be set by the light transition at dawn, and are calibrated to circadian (zeitgeber) time, which is measured from sunrise. Other rhythms are set by both dawn and dusk, and are calibrated to solar time that is measured from mid-day. Rhythms on circadian timing shift seasonally in tandem with the timing of dawn that occurs earlier in summer and later in winter. On the other hand, rhythms set to solar time are maintained independently of the season, the timing of noon being constant year-round. Various rhythms that run in-phase and out-of-phase with one another seasonally may provide a means to time and induce seasonal events such as flowering.
    Matched MeSH terms: Light
  15. Yeang HY
    J Exp Bot, 2013 Jul;64(10):2643-52.
    PMID: 23645867 DOI: 10.1093/jxb/ert130
    In photoperiodic flowering, long-day (LD) plants are induced to flower seasonally when the daylight hours are long, whereas flowering in short-day (SD) plants is promoted under short photoperiods. According to the widely accepted external coincidence model, flowering occurs in LD Arabidopsis when the circadian rhythm of the gene CONSTANS (CO) peaks in the afternoon, when it is light during long days but dark when the days are short. Nevertheless, extending this explanation to SD flowering in rice, Oriza sativa, requires LD and SD plants to have 'opposite light requirements' as the CO orthologue in rice, HEADING-DATE1 (Hd1), promotes flowering only under short photoperiods. This report proposes a role of the plant's solar rhythm in promoting seasonal flowering. The interaction between rhythmic genes entrained to the solar clock and those entrained to the circadian clock form the basis of an internal coincidence model that explains both LD and SD flowering equally well. The model invokes no presumption of opposite light requirements between LD and SD plants, and further argues against any specific requirement of either light or darkness for SD flowering. Internal coincidence predicts the inhibition of SD flowering of the rice plant by a night break (a brief interruption of light), while it also provides a plausible explanation for how a judiciously timed night break promotes Arabidopsis flowering even on short days. It is the timing of the light transitions (sunrise and sunset) rather than the duration of light or darkness per se that regulates photoperiod-controlled flowering.
    Matched MeSH terms: Light
  16. Badran MM, Alomrani AH, Harisa GI, Ashour AE, Kumar A, Yassin AE
    Biomed Pharmacother, 2018 Oct;106:1461-1468.
    PMID: 30119220 DOI: 10.1016/j.biopha.2018.07.102
    In the present study, docetaxel (DTX)-loaded poly(lactic-co-glycolic acid) (PLGA) and polycaprolactone (PCL) nanoparticles were successfully prepared and coated with chitosan (CS). The prepared nanoparticles (NPs) were evaluated for their particle size, zeta potential, particle morphology, drug entrapment efficiency (EE%), and in vitro drug release profile. The anticancer activity of DTX-loaded NPs was assessed in human HT29 colon cancer cell line utilizing MTT assay. The pharmacokinetics of DTX-loaded NPs was monitored in Wistar rats in comparison to DTX solution. The prepared NPs exhibited particle sizes in the range 177.1 ± 8.2-287.6 ± 14.3 nm. CS decorated NPs exhibited a significant increase in particle size and a switch of zeta potential from negative to positive. In addition, high EE% values were obtained for CS coated PCL NPs and PLGA NPs as 67.1 and 76.2%, respectively. Moreover, lowering the rate of DTX in vitro release was achieved within 48 h by using CS coated NPs. Furthermore, a tremendous increase in DTX cytotoxicity was observed by CS-decorated PLGA NPs compared to all other NPs including DTX-free-NPs and pure DTX. The in vivo study revealed significant enhancement in DTX bioavailability from CS-decorated PLGA NPs with more than 4-fold increase in AUC compared to DTX solution. In conclusion, CS-decorated PLGA NPs are a considerable DTX-delivery carrier with magnificent antitumor efficacy.
    Matched MeSH terms: Dynamic Light Scattering
  17. Kee YY, Tan SS, Yong TK, Nee CH, Yap SS, Tou TY, et al.
    Nanotechnology, 2012 Jan 20;23(2):025706.
    PMID: 22166812 DOI: 10.1088/0957-4484/23/2/025706
    Low-temperature growth of indium tin oxide (ITO) nanowires (NWs) was obtained on catalyst-free amorphous glass substrates at 250 °C by Nd:YAG pulsed-laser deposition. These ITO NWs have branching morphology as grown in Ar ambient. As suggested by scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), our ITO NWs have the tendency to grow vertically outward from the substrate surface, with the (400) plane parallel to the longitudinal axis of the nanowires. These NWs are low in electrical resistivity (1.6×10⁻⁴ Ω cm) and high in visible transmittance (~90–96%), and were tested as the electrode for organic light emitting devices (OLEDs). An enhanced current density of ~30 mA cm⁻² was detected at bias voltages of ~19–21 V with uniform and bright emission. We found that the Hall mobility of these NWs is 2.2–2.7 times higher than that of ITO film, which can be explained by the reduction of Coulomb scattering loss. These results suggested that ITO nanowires are promising for applications in optoelectronic devices including OLED, touch screen displays, and photovoltaic solar cells.
    Matched MeSH terms: Light
  18. Nee CH, Yap SL, Tou TY, Chang HC, Yap SS
    Sci Rep, 2016 Sep 23;6:33966.
    PMID: 27659184 DOI: 10.1038/srep33966
    Carbon nanomaterials exhibit novel characteristics including enhanced thermal, electrical, mechanical, and biological properties. Nanodiamonds; first discovered in meteorites are found to be biocompatible, non-toxic and have distinct optical properties. Here we show that nanodiamonds with the size of <5 nm are formed directly from ethanol via 1025 nm femtosecond laser irradiation. The absorption of laser energy by ethanol increased non-linearly above 100 μJ accompanied by a white light continuum arises from fs laser filamentation. At laser energy higher than 300 μJ, emission spectra of C, O and H in the plasma were detected, indicating the dissociation of C2H5OH. Nucleation of the carbon species in the confined plasma within the laser filaments leads to the formation of nanodiamonds. The energy dependence and the roles of the nonlinear phenomenon to the formation of homogeneous nanodiamonds are discussed. This work brings new possibility for bottom-up nanomaterials synthesis based on nano and ultrafast laser physics.
    Matched MeSH terms: Light
  19. Kanakaraju D, Jasni MAA, Pace A, Ya MH
    Environ Sci Pollut Res Int, 2021 Dec;28(48):68834-68845.
    PMID: 34282548 DOI: 10.1007/s11356-021-15440-x
    The performance of Cu/TiO2/FA composite, a hybrid adsorbent-photocatalyst consisting of copper-doped titania particles supported on fly ash, was optimized, under visible light irradiation, for the removal of the model dye pollutant methyl orange (MO) by using a response surface methodology and Box-Behnken experimental design. Three independent variables were considered for the optimization study: catalyst/solvent dosage (0.5 - 2.0 g/L), irradiation time (30-120 min), and the initial concentration (5- 25 ppm) of the dye. A 99.91% rate of removal was achieved using 2 g/L dosage, 5 ppm initial concentration, and 100 min of irradiation time as the optimal operating conditions. The recorded trends support the hypothesis of a combined and synergic adsorption-photocatalytic degradation process which fully exploits the "capture and destroy" approach for pollutant removal.
    Matched MeSH terms: Light
  20. Ismail N, Nazri NK, Abdullah AA, Wan Nik WMN, Wright LJ
    Data Brief, 2021 Feb;34:106738.
    PMID: 33521179 DOI: 10.1016/j.dib.2021.106738
    Polychloropolymethylstyrene (PCMS) polymers were synthesized with clay Cloisite and without clay Cloisite and chloromethylstyrene (CMS) combine with styrene (1:1) v/v or known as copolymer and clay Cloisite by the polymerization process. The attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectra of each polymer synthesized are reported. The spectra of IR shows the different value of the wavenumber and intensity for each set of different sample. The spectra can be as a reference for others to use in synthesizing this polymer and clay Cloisite for different type of application.
    Matched MeSH terms: Light
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