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Oxygen vacancy induced Bi2WO6 for the realization of photocatalytic CO2 reduction over the full solar spectrum: from the UV to the NIR region

Kong XY, Choo YY, Chai SP, Soh AK, Mohamed AR

Chem Commun (Camb), 2016 Dec 06;52(99):14242-14245.
PMID: 27872917

Photocatalytic CO2 reduction over the UV-Vis-NIR broad spectrum was realized for the first time. The presence of surface oxygen vacancy defects on Bi2WO6 resulted in significant photocatalytic enhancement over the pristine counterpart under UV and visible light irradiation. Meanwhile, the photocatalytic responsiveness of Bi2WO6-OV was successfully extended to the NIR region.

Matched MeSH terms: Light
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*
Fulltext Hydrothermal preparation of silver telluride nanostructures and photo-catalytic investigation in degradation of toxic dyes

Gholamrezaei S, Salavati-Niasari M, Ghanbari D, Bagheri S

Sci Rep, 2016;6:20060.
PMID: 26805744 DOI: 10.1038/srep20060

Different morphologies of Ag2Te nanostructures were synthesized using TeCl4 as a new precursor and hydrazine hydrate as reducing agent by a hydrothermal method. Various parameters that affect on morphology and purity of nanostructures were optimized. According to our experiments the best time and temperature for preparation of this nanostructure are 12 h and 120 °C. The photo-catalytic behaviour of nanostructures in presence of UV-visible light for degradation of methyl orange was investigated. Results show that the presence of UV light is necessary for an efficient degradation of dye in aqueous solution. On the other hand, as observations propose the Ag2Te reveal a strong photoluminescence peak at room temperature that could be attributed to high level transition in the semiconductor. Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) techniques and UV-visible scanning spectrometer (UV-Vis).

Matched MeSH terms: Light
Fulltext Synthesis, characterization, and performance evaluation of multilayered photoanodes by introducing mesoporous carbon and TiO2 for humic acid adsorption

Hosseini S, Jahangirian H, Webster TJ, Soltani SM, Aroua MK

Int J Nanomedicine, 2016;11:3969-78.
PMID: 27574426 DOI: 10.2147/IJN.S96558

Nanostructured photoanodes were prepared via a novel combination of titanium dioxide (TiO2) nanoparticles and mesoporous carbon (C). Four different photoanodes were synthesized by sol-gel spin coating onto a glassy substrate of fluorine-doped tin oxide. The photocatalytic activities of TiO2, TiO2/C/TiO2, TiO2/C/C/TiO2, and TiO2/C/TiO2/C/TiO2 photoanodes were evaluated by exposing the synthesized photoanodes to UV-visible light. The photocurrent density observed in these photoanodes confirmed that an additional layer of mesoporous carbon could successfully increase the photocurrent density. The highest photocurrent density of ~1.022 mA cm(-2) at 1 V/saturated calomel electrode was achieved with TiO2/C/C/TiO2 under an illumination intensity of 100 mW cm(-2) from a solar simulator. The highest value of surface roughness was measured for a TiO2/C/C/TiO2 combination owing to the presence of two continuous layers of mesoporous carbon. The resulting films had a thickness ranging from 1.605 µm to 5.165 µm after the calcination process. The presence of double-layer mesoporous carbon resulted in a 20% increase in the photocurrent density compared with the TiO2/C/TiO2 combination when only a single mesoporous carbon layer was employed. The improved performance of these photoanodes can be attributed to the enhanced porosity and increased void space due to the presence of mesoporous carbon. For the first time, it has been demonstrated here that the photoelectrochemical performance of TiO2 can be improved by integrating several layers of mesoporous carbon. Comparison of the rate of removal of humic acid by the prepared photoanodes showed that the highest performance from TiO2/C/C/TiO2 was due to the highest photocurrent density generated. Therefore, this study showed that optimizing the sequence of mesoporous carbon layers can be a viable and inexpensive method for enhanced humic acid removal.

Matched MeSH terms: Light*
Fulltext Direct synthesis of nanodiamonds by femtosecond laser irradiation of ethanol

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
Fulltext Seismic response of a light rail transit station equipped with braced viscous damper

Fateh, A., Hejazi, F., Ramanathan, R.A., Jaffar, M.S.

Pertanika Journal of Science & Technology, 2016;24(2):273-283.
MyJurnal

The use of the Light Rail Transit (LRT) system is currently preferred because LRT is sustainable,
improves travel options and facilitates swift mobility in urban areas. Hence, the structural stability
and safety of this public transportation system against seismic occurrences are indispensable. Given
that these structures cannot be considered conventional frames because of their complex architectural
design, focussing meticulously on reliable seismic design codes and structural rehabilitation techniques
is vital for the design of the lateral resistance system. One Malaysian LRT station is considered in this
study, and the seismic response of this train station when equipped with supplementary viscous damper
devices is evaluated. Thus, the LRT station is modelled through finite element simulation. The methods
of seismic analysis are limited to linear seismic analyses, namely, response spectrum and time history
analyses. Results derived in this study show a significant improvement in structural response when the
station is fitted with dampers; approximately 40% reduction in displacement is observed at the top joint
of the roof. Furthermore, the lateral base shears decrease by approximately 70%.

Matched MeSH terms: Light
Fulltext Hemangioblastoma in the setting of von hippel lindau disease: a case report

Raajini Devi K, Aida Zairani MI, Hazlita MI, Jemaima CH, Farizal F, Safinaz Mohd Khialdin

Journal of Surgical Academia, 2016;6(1):54-58.
MyJurnal

A 21-year-old Chinese gentleman with no known medical illness, presented with a history of right painless blurring of vision with central scotoma of two weeks duration. He also had a history of multiple episodes of seizures prior to presentation. Visual acuity was 1/60 with unremarkable anterior segment findings and no relative afferent pupillary defect. Fundus examination of the right eye revealed dilated and tortuous retinal veins with multiple retinal capillary hemangiomas and sub retinal hard exudates at the macula with edema. A diagnosis of Von Hippel Lindau disease was made when a posterior fossa mass suggestive of hemangioblastoma with obstructive hydrocephalus was seen on computed tomography of the brain. Craniotomy with nodule excision was performed. The retinal capillary hemangiomas were treated with the combination of laser photocoagulation and intravitreal Ranibizumab injections. Visual acuity subsequently improved to 6/36.

Matched MeSH terms: Light Coagulation
Fulltext LivePhantom: Retrieving Virtual World Light Data to Real Environments

Kolivand H, Billinghurst M, Sunar MS

PLoS One, 2016;11(12):e0166424.
PMID: 27930663 DOI: 10.1371/journal.pone.0166424

To achieve realistic Augmented Reality (AR), shadows play an important role in creating a 3D impression of a scene. Casting virtual shadows on real and virtual objects is one of the topics of research being conducted in this area. In this paper, we propose a new method for creating complex AR indoor scenes using real time depth detection to exert virtual shadows on virtual and real environments. A Kinect camera was used to produce a depth map for the physical scene mixing into a single real-time transparent tacit surface. Once this is created, the camera's position can be tracked from the reconstructed 3D scene. Real objects are represented by virtual object phantoms in the AR scene enabling users holding a webcam and a standard Kinect camera to capture and reconstruct environments simultaneously. The tracking capability of the algorithm is shown and the findings are assessed drawing upon qualitative and quantitative methods making comparisons with previous AR phantom generation applications. The results demonstrate the robustness of the technique for realistic indoor rendering in AR systems.

Matched MeSH terms: Light
Chemical-Induced Inhibition of Blue Light-Mediated Seedling Development Caused by Disruption of Upstream Signal Transduction Involving Cryptochromes in Arabidopsis thaliana

Ong WD, Okubo-Kurihara E, Kurihara Y, Shimada S, Makita Y, Kawashima M, et al.

Plant Cell Physiol, 2017 01 01;58(1):95-105.
PMID: 28011868 DOI: 10.1093/pcp/pcw181

Plants have a remarkable ability to perceive and respond to various wavelengths of light and initiate regulation of different cascades of light signaling and molecular components. While the perception of red light and the mechanisms of its signaling involving phytochromes are largely known, knowledge of the mechanisms of blue light signaling is still limited. Chemical genetics involves the use of diverse small active or synthetic molecules to evaluate biological processes. By combining chemicals and analyzing the effects they have on plant morphology, we identified a chemical, 3-bromo-7-nitroindazole (3B7N), that promotes hypocotyl elongation of wild-type Arabidopsis only under continuous blue light. Further evaluation with loss-of-function mutants confirmed that 3B7N inhibits photomorphogenesis through cryptochrome-mediated light signaling. Microarray analysis demonstrated that the effect of 3B7N treatment on gene expression in cry1cry2 is considerably smaller than that in the wild type, indicating that 3B7N specifically interrupts cryptochrome function in the control of seedling development in a light-dependent manner. We demonstrated that 3B7N directly binds to CRY1 protein using an in vitro binding assay. These results suggest that 3B7N is a novel chemical that directly inhibits plant cryptochrome function by physical binding. The application of 3B7N can be used on other plants to study further the blue light mechanism and the genetic control of cryptochromes in the growth and development of plant species.

Matched MeSH terms: Light*; Light Signal Transduction/drug effects; Light Signal Transduction/genetics; Light Signal Transduction/radiation effects
Effects of low-level laser irradiation on human blood lymphocytes in vitro

Al Musawi MS, Jaafar MS, Al-Gailani B, Ahmed NM, Suhaimi FM, Suardi N

Lasers Med Sci, 2017 Feb;32(2):405-411.
PMID: 28044209 DOI: 10.1007/s10103-016-2134-1

Low-level laser irradiation (LLLI) has various effects on cultured human lymphocytes in vitro, but little is known about such effects in whole blood. This study investigated whether LLLI affected lymphocyte count in human whole blood in vitro. A total number of 130 blood samples were collected from apparently healthy adult patients through venipuncture into tubes containing EDTA. Each sample was divided into two equal aliquots to be used as a non-irradiated control sample and an irradiated sample. The irradiated aliquot was subjected to laser wavelengths of 405, 589, and 780 nm with different fluences of 36, 54, 72, and 90 J/cm(2), at a fixed irradiance of 30 mW/cm(2). A paired student t test was used to compare between non-irradiated and irradiated samples. The lymphocyte counts were measured using a computerized hematology analyzer and showed a significant (P

Matched MeSH terms: Low-Level Light Therapy*
The application of ATR-FTIR spectroscopy and multivariate data analysis to study drug crystallisation in the stratum corneum

Goh CF, Craig DQ, Hadgraft J, Lane ME

Eur J Pharm Biopharm, 2017 Feb;111:16-25.
PMID: 27845181 DOI: 10.1016/j.ejpb.2016.10.025

Drug permeation through the intercellular lipids, which pack around and between corneocytes, may be enhanced by increasing the thermodynamic activity of the active in a formulation. However, this may also result in unwanted drug crystallisation on and in the skin. In this work, we explore the combination of ATR-FTIR spectroscopy and multivariate data analysis to study drug crystallisation in the skin. Ex vivo permeation studies of saturated solutions of diclofenac sodium (DF Na) in two vehicles, propylene glycol (PG) and dimethyl sulphoxide (DMSO), were carried out in porcine ear skin. Tape stripping and ATR-FTIR spectroscopy were conducted simultaneously to collect spectral data as a function of skin depth. Multivariate data analysis was applied to visualise and categorise the spectral data in the region of interest (1700-1500cm(-1)) containing the carboxylate (COO(-)) asymmetric stretching vibrations of DF Na. Spectral data showed the redshifts of the COO(-) asymmetric stretching vibrations for DF Na in the solution compared with solid drug. Similar shifts were evident following application of saturated solutions of DF Na to porcine skin samples. Multivariate data analysis categorised the spectral data based on the spectral differences and drug crystallisation was found to be confined to the upper layers of the skin. This proof-of-concept study highlights the utility of ATR-FTIR spectroscopy in combination with multivariate data analysis as a simple and rapid approach in the investigation of drug deposition in the skin. The approach described here will be extended to the study of other actives for topical application to the skin.

Matched MeSH terms: Light
Fulltext Image-based 3D canopy reconstruction to determine potential productivity in complex multi-species crop systems

Burgess AJ, Retkute R, Pound MP, Mayes S, Murchie EH

Ann Bot, 2017 Mar 01;119(4):517-532.
PMID: 28065926 DOI: 10.1093/aob/mcw242

BACKGROUND AND AIMS: Intercropping systems contain two or more species simultaneously in close proximity. Due to contrasting features of the component crops, quantification of the light environment and photosynthetic productivity is extremely difficult. However it is an essential component of productivity. Here, a low-tech but high-resolution method is presented that can be applied to single- and multi-species cropping systems to facilitate characterization of the light environment. Different row layouts of an intercrop consisting of Bambara groundnut ( Vigna subterranea ) and proso millet ( Panicum miliaceum ) have been used as an example and the new opportunities presented by this approach have been analysed.
METHODS: Three-dimensional plant reconstruction, based on stereo cameras, combined with ray tracing was implemented to explore the light environment within the Bambara groundnut-proso millet intercropping system and associated monocrops. Gas exchange data were used to predict the total carbon gain of each component crop.
KEY RESULTS: The shading influence of the tall proso millet on the shorter Bambara groundnut results in a reduction in total canopy light interception and carbon gain. However, the increased leaf area index (LAI) of proso millet, higher photosynthetic potential due to the C4 pathway and sub-optimal photosynthetic acclimation of Bambara groundnut to shade means that increasing the number of rows of millet will lead to greater light interception and carbon gain per unit ground area, despite Bambara groundnut intercepting more light per unit leaf area.
CONCLUSIONS: Three-dimensional reconstruction combined with ray tracing provides a novel, accurate method of exploring the light environment within an intercrop that does not require difficult measurements of light interception and data-intensive manual reconstruction, especially for such systems with inherently high spatial possibilities. It provides new opportunities for calculating potential productivity within multi-species cropping systems, enables the quantification of dynamic physiological differences between crops grown as monoculture and those within intercrops, and enables the prediction of new productive combinations of previously untested crops.

Matched MeSH terms: Light
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*
Fulltext Attraction factors for Paederus fuscipes ' dispersal, a vector of Paederus dermatitis towards human residential premises

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
Near-infrared activatable phthalocyanine-poly-L-glutamic acid conjugate: increased cellular uptake and light-dark toxicity ratio toward an effective photodynamic cancer therapy

Kiew LV, Cheah HY, Voon SH, Gallon E, Movellan J, Ng KH, et al.

Nanomedicine, 2017 05;13(4):1447-1458.
PMID: 28214608 DOI: 10.1016/j.nano.2017.02.002

In photodynamic therapy (PDT), the low absorptivity of photosensitizers in an aqueous environment reduces singlet oxygen generation efficiency and thereby decreases photosensitizing efficacy in biological conditions. To circumvent this problem, we designed a phthalocyanine-poly-L-glutamic acid conjugate (1-PG) made from a new phthalocyanine (Pc 1) monofunctionalized to allow adequate conjugation to PGA. The resulting 1-PG conjugate retained high absorptivity in the near-infrared (NIR) region at its λmax675nm in an aqueous environment. The 1-PG conjugate demonstrated good singlet oxygen generation efficiency, increased uptake by 4 T1 breast cancer cells via clathrin-mediated endocytosis, and enhanced photocytotoxic efficacy. The conjugate also displayed a high light-dark toxicity ratio, approximately 1.5-fold greater than zinc phthalocyanine at higher concentration (10 μM), an important feature for the reduction of dark toxicity and unwanted side effects. These results suggest that the 1-PG conjugate could be a useful alternative for deep tissue treatment with enhanced anti-cancer (PDT) efficacy.

Matched MeSH terms: Light
A highly emissive and stable zinc(ii) metal-organic framework as a host-guest chemopalette for approaching white-light-emission

Cai H, Xu LL, Lai HY, Liu JY, Ng SW, Li D

Chem Commun (Camb), 2017 Jun 27.
PMID: 28654101 DOI: 10.1039/c7cc03350h

A new adenine-containing metal-organic framework (MOF), [Zn4O(adenine)4(benzene-1,3-dicarboxylate)4Zn2] (named as ZnBDCA), was synthesized solvothermally. ZnBDCA possesses high quantum yield (>50%) and nano-channels that can encapsulate acriflavine molecules to build a host-guest chemopalette for approaching white-light emission.

Matched MeSH terms: Light
Two-dimensional bismuth oxybromide coupled with molybdenum disulphide for enhanced dye degradation using low power energy-saving light bulb

Lee WPC, Wong FH, Attenborough NK, Kong XY, Tan LL, Sumathi S, et al.

J Environ Manage, 2017 Jul 15;197:63-69.
PMID: 28324782 DOI: 10.1016/j.jenvman.2017.03.027

In the present work, two-dimensional bismuth oxybromide (BiOBr) was synthesized and coupled with co-catalyst molybdenum disulphide (MoS2) via a simple hydrothermal process. The photoactivity of the resulting hybrid photocatalyst (MoS2/BiOBr) was evaluated under the irradiation of 15 W energy-saving light bulb at ambient condition using Reactive Black 5 (RB5) as model dye solution. The photo-degradation of RB5 by BiOBr loaded with 0.2 wt% MoS2 (MoBi-2) exhibited more than 1.4 and 5.0 folds of enhancement over pristine BiOBr and titanium dioxide (Degussa, P25), respectively. The increased photocatalytic performance was a result of an efficient migration of excited electrons from BiOBr to MoS2, prolonging the electron-hole pairs recombination rate. A possible charge transfer diagram of this hybrid composite photocatalyst, and the reaction mechanism for the photodegradation of RB5 were proposed.

Matched MeSH terms: Light
Application of doped photocatalysts for organic pollutant degradation - A review

Khaki MRD, Shafeeyan MS, Raman AAA, Daud WMAW

J Environ Manage, 2017 Aug 01;198(Pt 2):78-94.
PMID: 28501610 DOI: 10.1016/j.jenvman.2017.04.099

Advanced oxidation process involves production of hydroxyl radical for industrial wastewater treatment. This method is based on the irradiation of UV light to photocatalysts such as TiO2 and ZnO for photodegradation of pollutant. UV light is used for irradiation in photocatalytic process because TiO2 has a high band gap energy which is around 3.2 eV. There can be shift adsorption to visible light by reducing the band gap energy to below 3.2 eV. Doped catalyst is one of the means to reduce band gap energy. Different methods are used for doped catalyst which uses transition metals and titanium dioxide. The band gap energy of three types of transition metals Fe, Cd and Co after being doped with TiO2, are around 2.88 ev, 2.97ev and 2.96 ev, respectively which are all below TiO2 energy. Some of the transition metals change the energy level to below 3.2 eV and the adsorption shifts to visible light for degradation of industrial pollutant after being doped with titanium dioxide. This paper aims at providing a deep insight into advanced oxidation processes, photocatalysts and their applications in wastewater treatment, doping processes and the effects of operational factors on photocatalytic degradation.

Matched MeSH terms: Light
Photobiomodulation therapy on wound treatment subsequent to Q-switched Nd: YAG laser tattoo removal in rat model

Imrigha NAA, Bidin N, Lau PS, Musa N, Zakaria N, Krishnan G

J Biophotonics, 2017 Oct;10(10):1287-1291.
PMID: 28464516 DOI: 10.1002/jbio.201600295

Q-switched Nd: YAG laser is the most effective laser for tattoo removal. Photobiomodulation (PBM) therapy is an alternative method applied to accelerate the wound healing. This paper investigated the effects of PBM therapy using 808 nm diode laser on tattooed skin after laser tattoo removal. Forty-five rats were selected and tattooed with black ink on their dorsal, and then distributed into three groups. G0 was received non-laser irradiation. G1 was treated by laser tattoo removal using 1064 nm with energy density of 3.4 J/cm2 without PBM therapy, while G2 was treated daily with PBM therapy using 808 nm diode laser of 5 J/cm2 after a single session of laser tattoo removal. The effects of tattoo removal and healing progress of the wound were analyzed using histological studies. Findings showed 808 nm laser promotes the healing process through enhancing epithelialization and collagen deposition. Moreover, PBM therapy stimulated immune cells to improve phagocytosis process for removing the tattoo ink fragments effectively. The PBM therapy treated group was capable of improving the healing process and increasing the quality of skin following the laser tattoo removal. It was also found that stimulation of cellular function by PBM therapy increased tattoo clearance efficiency.

Matched MeSH terms: Low-Level Light Therapy*
Fulltext Determination of the difference on color changes of watermelons by laser light backscattering imaging

Mohd Ali M, Hashim N, Bejo SK, Shamsudin R

J Food Sci Technol, 2017 Oct;54(11):3650-3657.
PMID: 29051660 DOI: 10.1007/s13197-017-2826-y

The potential of laser light backscattering imaging was investigated for monitoring color parameters of seeded and seedless watermelons during storage. Two watermelon cultivars were harvested and stored for 3 weeks with seven measuring storage days (0, 4, 8, 12, 15, 18, and 21). The color parameters of watermelons were monitored using the conventional colorimetric methods (L*, a*, b*, C*, H*, and ∆E*) and laser light backscattering imaging system. A laser diode emitting at 658 nm and 30 mW power was used as a light source to obtain the backscattering image. The backscattering images were evaluated by the extraction of backscattering parameters based on the mean pixel values. The results showed that a good color prediction was achieved by the seedless watermelon with the R2 are all above 0.900. Thus, the application of the laser light backscattering imaging can be used for evaluating the color parameters of watermelons during the storage period.

Matched MeSH terms: Light

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