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https://www.readbyqxmd.com/read/29031210/effect-of-photoactivated-riboflavin-on-the-biodegradation-resistance-of-root-dentin-collagen
#1
Balasankar Meera Priyadarshini, Thong Beng Lu, Amr S Fawzy
This study was conducted to evaluate the effect of UVA-activated 1% riboflavin solution on structural integrity; mechanical properties and stability; and collagenase-mediated collagen solubilisation resistance of demineralized root dentin collagen matrix. Root dentin specimens demineralized with 17% EDTA for 7days were treated with 1% RF for 1min followed by UVA photo-activation at intensity 7mW/cm(2) for 1min. Control specimens were completely devoid of riboflavin and/or UVA treatments. Specimens were challenged with bacterial collagenase type-I solution for different time-periods at 37°C...
October 8, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/29031151/fabrication-of-green-dye-sensitized-solar-cell-based-on-zno-nanoparticles-as-a-photoanode-and-graphene-quantum-dots-as-a-photo-sensitizer
#2
Golnoush Zamiri, Samira Bagheri
Zero-dimensional graphene quantum dots (GQDs) consist of single- or few-layer graphene with a size less than 20 nm and stand for a new type of QDs with unique properties combining the graphene nature and size-resulted quantum effects. GQDs possess unique optical and electronic properties, and in particular possess a band-gap less than 2.0 eV because of quantum confinement and edge effects. In this study, we investigated the performance of DSSCs using different thicknesses of ZnO nanoparticles as a photo-anode and GQDs as a green photosensitizer...
October 7, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/29028861/the-rationale-of-anti-aging-cosmetic-ingredients
#3
Michele Verschoore, Marion Nielson
<p>Anti-aging cosmetics are a mainstay in the skin care regimen irrespective of gender or human ethnics. Skin aging involves functional slowdown combined with environmental induced alterations. This paper focuses on cosmetic ingredients that aim at alleviating the signs of skin aging, with proven/controlled results of efficacy. Anti-aging skin care widely benefits from new ingredients and modern evaluation methods that can substantiate the effects of innovative products in a perceivable and sensitive manner...
June 1, 2017: Journal of Drugs in Dermatology: JDD
https://www.readbyqxmd.com/read/29028614/simultaneous-determination-of-five-alternaria-toxins-in-cereals-using-quechers-based-methodology
#4
Jian Zhou, Jiao-Jiao Xu, Zeng-Xuan Cai, Bai-Fen Huang, Mi-Cong Jin, Yi-Ping Ren
Two analytical approaches, including ultra-high performance liquid chromatograph linked with photo-diode array/fluorescence detector, and ultra-high performance liquid chromatography-tandem mass spectrometry, have been proposed for simultaneous determination of five Alternaria toxins in cereals, which both based on QuEChERS strategy. After QuEChERS extraction and salting out, the collected supernatant was subjected to an extra dispersive liquid-liquid microextraction step prior to quantitative analysis. Response surface methodology based on central composite design was employed to optimize the micro-extraction conditions...
October 4, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/29028581/size-controlled-and-optical-properties-of-platinum-nanoparticles-by-gamma-radiolytic-synthesis
#5
Elham Gharibshahi, Elias Saion, Ahmadreza Ashraf, Leila Gharibshahi
Gamma radiolytic synthesis was used to produce size-controlled spherical platinum nanoparticles from an aqueous solution containing platinum tetraammine and polyvinyl pyrrolidone. The structural characterizations were performed using X-ray diffraction, and transmission electron microscopy. The transmission electron microscopy was used to determine the average particle diameter, which decreased from 4.4nm at 80kGy to 2.8nm at 120kGy. The UV-visible absorption spectrum was measured and found that platinum nanoparticles exhibit two steady absorption maxima in UV regions due to plasmonic excitation of conduction electrons, which blue shifted to lower wavelengths with a decrease in particle size...
September 9, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/29028472/waterborne
#6
Kwesi Reynolds
These photos capture the Flint water crisis from the perspective of a photographer and cinematographer who is a resident of Flint. They represent citizens' struggles, town hall meetings, and some of the city's repair efforts. They also illuminate environmental injustice as a violation of human rights.
October 1, 2017: AMA Journal of Ethics
https://www.readbyqxmd.com/read/29028347/switchable-plasmonic-metasurfaces-with-high-chromaticity-containing-only-abundant-metals
#7
Kunli Xiong, Daniel Tordera, Gustav Emilsson, Oliver Olsson, Ulrika Linderhed, Magnus P Jonsson, Andreas B Dahlin
Plasmonic color generation offers several advantages but is also limited by the cost and availability of noble metals like gold. In this work we present color-tuneable metasurfaces with high chromaticity and reflectivity consisting of an aluminum mirror, a dielectric spacer and a plasmonic nanohole array in copper. Copper is shown to be an excellent alternative to gold when properly protected from oxidation and makes it possible to generate a wide RGB gamut covering 27% of the standard RGB. By patterning the metasurfaces into microscale pixel triplets, color photos can be well reproduced with high resolution over wafer-sized areas...
October 13, 2017: Nano Letters
https://www.readbyqxmd.com/read/29028294/carbon-dots-g-c3n4-nanoheterostructures-based-signal-generation-tags-for-photoelectrochemical-immunoassay-of-cancer-biomarkers-coupling-with-copper-nanoclusters
#8
Shuzhen Lv, Yi Li, Kangyao Zhang, Zhenzhen Lin, Dianping Tang
A class of 0-dimensional/2-dimensional (0D/2D) nanoheterostructures based on carbon quantum dots (CQDs) and graphitic carbon nitride (g-C3N4) was designed as the signal-generation tags for the sensitive photoelectrochemical (PEC) immunoassay of prostate-specific antigen (PSA) coupling with the copper nanoclusters (CuNCs). Combination of CQDs with g-C3N4 promoted the photoexcited electron/hole separation, and largely increased the photocurrents of the nanoheterostructures. Initially, a sandwich-type immunoreaction was carried out on monoclonal anti-PSA antibody-coated microplate by using PSA aptamer linked with CuNCs as the tracer...
October 13, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29028145/ultrafast-dynamics-of-a-fluorescent-tetrazolium-compound-in-solution
#9
Tom Bolze, Jan-Lucas Wree, Florian Kanal, Domenik Schleier, Patrick Nuernberger
Tetrazolium salts are exploited in various fields of research by virtue of their low reduction potentials. Increasingly, associated applications also attend to the photochemical and luminescence properties of these systems. Here, we investigate the photo-induced dynamics of phenyl-benzo[c]tetrazolo-cinnolinium chloride (PTC), one of the very few known fluorescent tetrazolium compounds, using time-correlated single-photon counting, femtosecond fluorescence upconversion, and ultrafast transient absorption spectroscopy...
October 13, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/29028040/ex-vivo-validation-of-photo-magnetic-imaging
#10
Alex Luk, Farouk Nouizi, Hakan Erkol, Mehmet B Unlu, Gultekin Gulsen
We recently introduced a new high-resolution diffuse optical imaging technique termed photo-magnetic imaging (PMI), which utilizes magnetic resonance thermometry (MRT) to monitor the 3D temperature distribution induced in a medium illuminated with a near-infrared light. The spatiotemporal temperature distribution due to light absorption can be accurately estimated using a combined photon propagation and heat diffusion model. High-resolution optical absorption images are then obtained by iteratively minimizing the error between the measured and modeled temperature distributions...
October 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/29027950/control-design-and-digital-implementation-of-a-fast-2-degree-of-freedom-translational-optical-image-stabilizer-for-image-sensors-in-mobile-camera-phones
#11
Jeremy H-S Wang, Kang-Fu Qiu, Paul C-P Chao
This study presents design, digital implementation and performance validation of a lead-lag controller for a 2-degree-of-freedom (DOF) translational optical image stabilizer (OIS) installed with a digital image sensor in mobile camera phones. Nowadays, OIS is an important feature of modern commercial mobile camera phones, which aims to mechanically reduce the image blur caused by hand shaking while shooting photos. The OIS developed in this study is able to move the imaging lens by actuating its voice coil motors (VCMs) at the required speed to the position that significantly compensates for imaging blurs by hand shaking...
October 13, 2017: Sensors
https://www.readbyqxmd.com/read/29027884/accuracy-and-reliability-of-a-handheld-nonmydriatic-fundus-camera-for-the-remote-detection-of-optic-disc-edema
#12
Lulu Bursztyn, Maria A Woodward, Wayne T Cornblath, Hilary M Grabe, Jonathan D Trobe, Leslie Niziol, Lindsey B De Lott
BACKGROUND: Optic disc edema can be an important indicator of serious neurological disease, but is poorly detected using the direct ophthalmoscope. Portable fundus photography may overcome this difficulty. INTRODUCTION: The purpose of this study was to determine the sensitivity and specificity of a handheld, nonmydriatic fundus camera for the detection of optic disc edema. MATERIALS AND METHODS: Retrospective review of nonmydriatic optic disc photographs taken with a portable fundus camera (Pictor Plus; Volk Optical, Mentor, OH) from the University of Michigan Neuro-Ophthalmology Clinics...
October 13, 2017: Telemedicine Journal and E-health: the Official Journal of the American Telemedicine Association
https://www.readbyqxmd.com/read/29027459/plasmon-induced-selective-oxidation-reaction-at-single-walled-carbon-nanotubes
#13
Satoshi Yasuda, Takahiro Yoshii, Shohei Chiashi, Shigeo Maruyama, Kei Murakoshi
Local surface plasmon resonance (LSPR)-induced oxidation of semiconducting and metallic single-walled nanotubes (SWNTs) on the nanometer scale was investigated using surface enhanced Raman scattering (SERS) measurements. An isolated SWNT was supported on a well-defined Au nanodimer structure that possesses an LSPR field at the nanogap under light irradiation, and highly intense SERS spectra of the SWNT at the gap region were measured. SERS analysis under O2-saturated solutions and the addition of reactive oxygen species inhibitors demonstrated that condensed singlet oxygen ((1)O2), which is one of the reactive oxygen species, was efficiently generated from a semiconducting SWNT at the nanogap by the LSPR field, and led to local oxidation of the tube...
October 13, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29027149/sequencing-larger-intact-proteins-30-70-kda-with-activated-ion-electron-transfer-dissociation
#14
Nicholas M Riley, Michael S Westphall, Joshua J Coon
The analysis of intact proteins via mass spectrometry can offer several benefits to proteome characterization, although the majority of top-down experiments focus on proteoforms in a relatively low mass range (<30 kDa). Recent studies have focused on improving the analysis of larger intact proteins (up to ~75 kDa), but they have also highlighted several challenges to be addressed. One major hurdle is the efficient dissociation of larger protein ions, which often to do not yield extensive fragmentation via conventional tandem MS methods...
October 12, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/29026907/a-two-dimensional-layered-cds-c2n-heterostructure-for-visible-light-driven-photocatalysis
#15
Xukai Luo, Guangzhao Wang, Yuhong Huang, Biao Wang, Hongkuan Yuan, Hong Chen
In this work, we employ hybrid density functional theory calculations to design a two-dimensional layered CdS/C2N heterostructure for visible light photocatalytic water splitting to produce hydrogen. The calculation results show that the conduction band minimum (CBM) and the valence band maximum (VBM) of C2N monolayers are lower than those of CdS nanosheets by about 0.76 eV and 0.44 eV, respectively. The type-II band alignment, density of states, Bader charge analysis, and charge density difference of the CdS/C2N heterostructure indicate that the photogenerated electrons migrate from the CdS monolayer to the C2N monolayer, favoring the separation and transfer of photogenerated charge carriers, which restrains the recombination of photogenerated carriers and enhances the photocatalytic efficiency...
October 13, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29026899/few-layered-metallic-1t-mos2-tio2-with-exposed-001-facets-two-dimensional-nanocomposites-for-enhanced-photocatalytic-activities
#16
HyukSu Han, Kang Min Kim, Chan-Woo Lee, Caroline S Lee, Rajendra C Pawar, Jacob L Jones, Yu-Rim Hong, Jeong Ho Ryu, Taeseup Song, Suk Hyun Kang, Heechae Choi, Sungwook Mhin
Titanium dioxide (TiO2) with exposed (001) facets (TiO2(001)) has attractive photocatalytic properties. However, the high recombination rate of the photo-excited charge carriers on this surface often limits its application. Here, we report that a few-layered 1T-MoS2 coating on TiO2(001) nanosheets (abbreviated as MST) can be a promising candidate that overcomes some of the challenges of TiO2(001). Computational and experimental results demonstrate that MST as a photocatalyst exhibits a significantly low-charge recombination rate as well as excellent long-term durability...
October 13, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29026828/objective-outcomes-of-minimally-invasive-temporalis-tendon-transfer-for-prolonged-complete-facial-paralysis
#17
Michal Brichacek, Babar Sultan, Kofi D Boahene, Lisa Ishii, Patrick J Byrne
OBJECTIVES: We describe an approach to reanimation of complete, prolonged facial paralysis using minimally invasive temporalis tendon transfer (MIT3) by the melolabial or transoral approach. Objective outcome measures are evaluated based on symmetry, and grading of preoperative/post-operative results and the scar at the melolabial fold. STUDY DESIGN: Retrospective cohort study. METHODS: Twenty-five patients undergoing the MIT3 technique were studied...
August 2017: Plastic Surgery
https://www.readbyqxmd.com/read/29025643/comb-shaped-temperature-tunable-and-water-soluble-porphyrin-based-thermoresponsive-copolymer-for-enhanced-photodynamic-therapy
#18
Changling Liu, Yanhui Li, Bo Gao, Yanwei Li, Qian Duan, Toyoji Kakuchi
A novel comb-shaped porphyrin end-functionalized poly(N-isopropylacrylamide)-b-poly[oligo (ethylene glycol methyl ether methacrylate)] (Por-PNIPAM-b-POEGMA) was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Due to the incorporation of hydrophilic POEGMA contents, the copolymer shows the lower critical solution temperatures (LCST) of 37-41.8°C higher than PNIPAM. Moreover, this copolymer showed efficient singlet oxygen under light irradiation at 650nm, and the productivity of singlet oxygen was 0...
January 1, 2018: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/29024136/streptavidin-as-a-scaffold-for-light-induced-long-lived-charge-separation
#19
Sascha Georg Keller, Andrea Pannwitz, Hendrik Mallin, Oliver Wenger, Thomas R Ward
Long-lived photo-driven charge separation is demonstrated by assembling a triad on a protein scaffold. For this purpose, a biotinylated triarylamine was added to a Ru(II)- streptavidin conjugate bearing a methyl viologen electron acceptor covalently linked to the N-terminus of streptavidin. To improve the rate and lifetime of the electron transfer a negative patch consisting of up to three negatively charged amino acids was engineered via mutagenesis close to the biotin-binding pocket of streptavidin. Time-resolved laser spectroscopy revealed that the covalent attachment and the negative patch was beneficial for charge separation within the streptavidin hosted triad: the charge separate state was generated within the duration of the excitation laser pulse, and lifetimes up to 3120 ns could be achieved with the optimized supramolecular triad...
October 10, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29023122/water-photo-oxidation-initiated-by-surface-bound-organic-chromophores
#20
Michael S Eberhart, Degao Wang, Renato N Sampaio, Seth L Marquard, Bing Shan, M Kyle Brennaman, Gerald J Meyer, Christopher Dares, Thomas J Meyer
Organic chromophores can be synthesized by established methods and offer an opportunity to expand overall solar spectrum utilization for dye sensitized photoelectrosynthesis cells (DSPECs). However, there are complications in the use of organic chromophores arising from the instability of their oxidized forms, the inability of their oxidized forms to activate a water oxidation catalyst, or the absence of a sufficiently reducing excited state for electron injection into appropriate semiconductors. Three new triarylamine donor-acceptor organic dyes have been investigated here for visible light driven water oxidation...
October 12, 2017: Journal of the American Chemical Society
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