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https://www.readbyqxmd.com/read/28937927/the-effects-of-photobiomodulation-delivered-by-light-emitting-diode-on-stem-cells-from-human-exfoliated-deciduous-teeth-a-study-on-the-relevance-to-pluripotent-stem-cell-viability-and-proliferation
#1
Katia Llanos do Vale, Durvanei Augusto Maria, Lara Cristina Picoli, Alessandro Melo Deana, Marcelo Betti Mascaro, Raquel Agnelli Mesquita Ferrari, Sandra Kalil Bussadori, Kristianne Porta Santos Fernandes
OBJECTIVE: Photobiomodulation (PBM) can modulate the proliferation of some types of stem cells. However, few reports have addressed the effects of PBM delivered by light-emitting diode (LED) on stem cells obtained from the pulp tissue of deciduous teeth. The aim of the present study was to investigate the effect of PBM delivered by red LED (630 nm, 75 mW, 37 mW/cm(2)) with different radiant exposures on the cell cycle, mitochondrial membrane potential, and senescence of stem cells from human exfoliated deciduous teeth (SHED)...
September 21, 2017: Photomedicine and Laser Surgery
https://www.readbyqxmd.com/read/28937205/electrospun-p-type-nickel-oxide-semiconducting-nanowires-for-low-voltage-field-effect-transistors
#2
Ao Liu, You Meng, Huihui Zhu, Yong-Young Noh, Guoxia Liu, Fukai Shan
One-dimensional metal-oxide nanowires are regarded as important building blocks in nanoscale electronics due to their unique mechanical and electrical properties. In this work, p-type nickel oxide nanowires (NiO NWs) were fabricated by combining sol-gel and electrospinning processes. The polyvinylpyrrolidone (PVP) with 1,300,000 molecular weight was used as the polymer matrix to increase the viscosity of NiO precursor solution. The formation and properties of the as-spun NiO/PVP composite NWs before/after calcination treatment were investigated using various techniques...
September 22, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28936529/high-performance-flexible-inverted-organic-light-emitting-diodes-by-exploiting-mos2-nanopillar-arrays-as-electron-injecting-and-light-coupling-layers
#3
Kunping Guo, Changfeng Si, Ceng Han, Saihu Pan, Guo Chen, Yanqiong Zheng, Wenqing Zhu, Jianhua Zhang, Chang Sun, Bin Wei
Inverted organic light-emitting diodes (IOLEDs) on plastic substrates have great potential application in flexible active-matrix displays. High energy consumption, instability and poor electron injection are key issues limiting the commercialization of flexible IOLEDs. Here, we have systematically investigated the electrooptical properties of molybdenum disulfide (MoS2) and applied it in developing highly efficient and stable blue fluorescent IOLEDs. We have demonstrated that MoS2-based IOLEDs can significantly improve electron-injecting capacity...
September 22, 2017: Nanoscale
https://www.readbyqxmd.com/read/28935534/neurosurgical-microscopic-solid-laser-based-light-inhibits-photobleaching-during-fluorescence-guided-brain-tumor-removal-with-5-aminolevulinic-acid
#4
Fumitaka Matsuda, Naokado Ikeda, Yoshinaga Kajimoto, Naosuke Nonoguchi, Koji Takeuchi, Masao Fukumura, Shinji Kawabata, Motomasa Furuse, Tetsuo Sugano, Taku Sato, Kiyoshi Saito, Toshihiko Kuroiwa
BACKGROUND: Fluorescence image guided surgery (FIGS) with 5-aminolevulinic acid for malignant gliomas improves surgical outcome. One of the problems during FIGS is photobleaching under surgical microscopic white light. A solid laser-based white light source for neurosurgery that we developed does not include light with a wavelength of around 405nm, which is strongly absorbed by protoporphyrin IX. In the present study, we examined the efficacy of this light source to prevent the photobleaching of protoporphyrin IX-induced fluorescence...
September 18, 2017: Photodiagnosis and Photodynamic Therapy
https://www.readbyqxmd.com/read/28933857/giant-enhancement-of-cathodoluminescence-of-monolayer-transitional-metal-dichalcogenides-semiconductors
#5
Shoujun Zheng, Jinkyu So, Fucai Liu, Zheng Liu, Nikolay I Zheludev, Hong Jin Fan
Monolayer two-dimensional transitional metal dichalcogenides, such as MoS2, WS2 and WSe2, are direct band gap semiconductors with large exciton binding energy. They attract growing attentions for opto-electronic applications including solar cells, photo-detectors, light-emitting diodes and photo-transistors, capacitive energy storage, photodynamic cancer therapy and sensing on flexible platforms. While light-induced luminescence has been widely studied, luminescence induced by injection of free electrons could promise another important applications of these new materials...
September 21, 2017: Nano Letters
https://www.readbyqxmd.com/read/28931910/the-role-of-charge-balance-and-excited-state-levels-on-device-performance-of-exciplex-based-phosphorescent-organic-light-emitting-diodes
#6
Sangyeob Lee, Hyun Koo, Ohyun Kwon, Young Jae Park, Hyeonho Choi, Kwan Lee, Byungmin Ahn, Young Min Park
The design of novel exciplex-forming co-host materials provides new opportunities to achieve high device performance of organic light emitting diodes (OLEDs), including high efficiency, low driving voltage and low efficiency roll-off. Here, we report a comprehensive study of exciplex-forming co-host system in OLEDs including the change of co-host materials, mixing composition of exciplex in the device to improve the performance. We investigate various exciplex systems using 5-(3-4,6-diphenyl-1,3,5-triazin-2-yl)phenyl-3,9-diphenyl-9H-carbazole, 5-(3-4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-9-phenyl-9H-3,9'-bicarbazole, and 2-(3-(6,9-diphenyl-9H-carbazol-4-yl)phenyl)-4-phenylbenzo[4,5]thieno[3,2-d]pyrimidine, as electron transporting (ET: electron acceptor) hosts and 9,9'-dipenyl-9H, 9'H-3,3'-bicarbazole and 9-([1,1'-biphenyl]-4-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole as hole transporting (HT: electron donor) hosts...
September 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28931857/eu-3-activated-la2moo6-la2wo6-red-emitting-phosphors-with-ultrabroad-excitation-band-for-white-light-emitting-diodes
#7
Peng Du, Jae Su Yu
A series of novel Eu(3+)-activated La2MoO6-La2WO6 red-emitting phosphors have been successfully prepared by a citrate-assisted sol-gel process. Both photoluminescence excitation and emission spectra suggest that the resultant products have the strong ultrabroad absorption band ranging from 220 to 450 nm. Under the excitation of 379 nm, the characteristic emissions of Eu(3+) ions corresponding to the (5)D0 → (7)F J transitions are observed in the doped samples. The optimal doping concentration for Eu(3+) ions is found to be 12 mol% and the quenching mechanism is attributed to the dipole-dipole interaction...
September 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28931040/newborn-skin-reflection-proof-of-concept-for-a-new-approach-for-predicting-gestational-age-at-birth-a-cross-sectional-study
#8
Zilma Silveira Nogueira Reis, Gabriela Luiza Nogueira Vitral, Ingrid Michelle Fonseca de Souza, Maria Albertina Santiago Rego, Rodney Nascimento Guimaraes
BACKGROUND: Current methods to assess the gestational age during prenatal care or at birth are a global challenge. Disadvantages, such as low accessibility, high costs, and imprecision of clinical tests and ultrasonography measurements, may compromise health decisions at birth, based on the gestational age. Newborns' organs and tissues can indirectly indicate their physical maturity, and we hypothesized that evolutionary changes in their skin, detected using an optoelectronic device meter, may aid in estimating the gestational age...
2017: PloS One
https://www.readbyqxmd.com/read/28930790/photography-in-dermatologic-surgery-selection-of-an-appropriate-lighting-solution-for-a-particular-clinical-application
#9
Brian R Chen, Emily Poon, Murad Alam
BACKGROUND: Lighting is an important component of consistent, high-quality dermatologic photography. There are different types of lighting solutions available. OBJECTIVE: To evaluate currently available lighting equipment and methods suitable for procedural dermatology. MATERIALS AND METHODS: Overhead lighting, built-in camera flashes, external flash units, studio strobes, and light-emitting diode (LED) light panels were evaluated with regard to their utility for dermatologic surgeons...
September 19, 2017: Dermatologic Surgery: Official Publication for American Society for Dermatologic Surgery [et Al.]
https://www.readbyqxmd.com/read/28930347/a-paper-triboelectric-nanogenerator-for-self-powered-electronic-systems
#10
Yanchao Mao, Nan Zhang, Yingjie Tang, Meng Wang, Mingju Chao, Erjun Liang
Paper, as one of the most important inventions of mankind, is still widely used in our daily life. In this study, the paper is explored as a platform for power sources based on the universally known triboelectric friction. A novel paper triboelectric nanogenerator (P-TENG) was successfully developed, which could harvest mechanical energy from ambient sources and generate considerable electrical energy. The maximum power density of the P-TENG reached 53 W m(-2). In addition, the P-TENG possesses a natural advantage of being able to be integrated within a book, and thus can effectively convert mechanical energy from the action of turning book pages into electricity...
September 20, 2017: Nanoscale
https://www.readbyqxmd.com/read/28929624/structural-mimics-of-phenyl-pyridine-ppy-substituted-phosphorescent-cyclometalated-homo-and-heteroleptic-iridium-iii-complexes-for-organic-light-emitting-diodes-an-overview
#11
REVIEW
Aravind Babu Kajjam, Sivakumar Vaidyanathan
Today organic light emitting diodes are a topic of significant academic and industrial research interest. OLED technology is used in commercially available displays, and efforts have been directed to improve this technology. Design and synthesis of phosphorescent based transition metals are capable of harvesting both singlet and triplet excitons and achieve 100 % internal quantum efficiency is an active area of research. Among all the transition metals, iridium is considered a prime candidate for OLEDs due to its prominent photophysical characteristics...
September 20, 2017: Chemical Record: An Official Publication of the Chemical Society of Japan ... [et Al.]
https://www.readbyqxmd.com/read/28929358/green-synthesis-of-inp-zns-core-shell-quantum-dots-for-application-in-heavy-metal-free-light-emitting-diodes
#12
Tsung-Rong Kuo, Shih-Ting Hung, Yen-Ting Lin, Tzu-Lin Chou, Ming-Cheng Kuo, Ya-Pei Kuo, Chia-Chun Chen
Quantum dot light-emitting diodes (QD-LEDs) have been considered as potential display technologies with the characterizations of high color purity, flexibility, transparency, and cost efficiency. For the practical applications, the development of heavy-metal-free QD-LEDs from environment-friendly materials is the most important issue to reduce the impacts on human health and environmental pollution. In this work, heavy-metal-free InP/ZnS core/shell QDs with different fluorescence were prepared by green synthesis method with low cost, safe, and environment-friendly precursors...
September 19, 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28929136/allochroic-thermally-activated-delayed-fluorescence-diodes-through-field-induced-solvatochromic-effect
#13
Chunmiao Han, Chunbo Duan, Weibo Yang, Mingchen Xie, Hui Xu
Allochroic organic light-emitting devices (AOLEDs) characterized by field-dependent emissive color variation are promising as visible signal response units for intelligent applications. Most of the AOLEDs were realized by changing their recombination zones or inter- and intramolecular energy transfer, rendering the limited repeatability, stability, and electroluminescence (EL) performance. We report a novel thermally activated delayed fluorescence (TADF) diode that featured a successive and irreversible emission color change from bluish green to deep blue during voltage increase, which uses the significant influence of host polarity on the emission color of TADF dyes, namely, solvatochromic effect...
September 2017: Science Advances
https://www.readbyqxmd.com/read/28927602/solid-state-photoluminescence-thermoplastic-starch-film-containing-graphene-quantum-dots
#14
Siamak Javanbakht, Hassan Namazi
Fluorescent polymer films, a matrix of thermoplastic starch (TPS) based bio-polymer and graphene quantum dots (GQDs) were fabricated by a casting method. The GQDs provide solid state fluorescent properties to the prepared thermoplastic starch graphene quantum dots (TPS/GQD). The fluorescent, thermal, mechanical and optical properties of TPS/GQD were investigated. High optical transparency (88-91%) and well dispersion of GQDs (1-17wt%) in the polymeric matrix of TPS/GQD nanocomposite was observed. The maximum photoluminescence intensity of materials has been obtained at 50wt% of GQD content...
November 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28926231/resonance-emission-enhancement-ree-for-narrow-band-red-emitting-a2gef6-mn-4-a-na-k-rb-cs-phosphors-synthesized-via-a-precipitation-cation-exchange-route
#15
Hongzhou Lian, Qingming Huang, Yeqing Chen, Kai Li, Sisi Liang, Mengmeng Shang, Manman Liu, Jun Lin
Narrow band red-emitting A2GeF6:Mn(4+) (A = Na, K, Rb, Cs) phosphors were prepared through a two-step precipitation-cation exchange route using a K2MnF6 precursor as the Mn(4+) source. The phase purity, morphology, and constituent were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectric spectroscopy (XPS), and electron paramagnetic resonance (EPR) examination. Optical properties were investigated by photoluminescence spectra (PL and PLE) and high-resolution PL. A temperature-dependent PL examination was performed to investigate the electron-phonon coupling emission mechanism of Mn(4+) in these alkali fluorogermanates...
September 19, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28926227/vertically-stacked-and-self-encapsulated-van-der-waals-heterojunction-diodes-using-two-dimensional-layered-semiconductors
#16
Jinshui Miao, Zhihao Xu, Li Qing, Arthur Bowman, Suoming Zhang, Weida Hu, Zhixian Zhou, Chuan Wang
Van der Waals heterojunctions using 2D semiconducting materials could overcome the defect issues included by lattice mismatch in conventional epitaxially-grown heterojunctions with bulk materials and could enable a much wider palette for choice of materials and more sophisticated device design. Such 2D heterojunction devices are of great interest for important functional devices such as diodes, bipolar junction transistors, light-emitting diodes, and photodetectors. In this paper, we demonstrate a truly vertical p-n heterojunction diode built from 2D semiconductors (MoS2 and BP) and compare its performance against conventional lateral 2D heterojunction devices...
September 19, 2017: ACS Nano
https://www.readbyqxmd.com/read/28926075/high-efficiency-quantum-dot-light-emitting-diodes-from-positive-aging
#17
Krishna P Acharya, Alexandre Titov, Jake Hyvonen, Chenggong Wang, Jean Tokarz, Paul H Holloway
Colloidal quantum dot-polymer hybrid light emitting diodes (QLEDs) that exhibit external quantum efficiencies >12% for all three primary colors (21% from green) have been demonstrated. These high efficiencies result in part from a positive aging effect reported here for the first time, where positive aging means the efficiency of the QLED increased with time. We have achieved 470 h operational life time (T90) at 2550 nits for red QLEDs. At longer times, negative aging phenomena lead to lower luminance and limit the lifetime of the QLEDs...
September 19, 2017: Nanoscale
https://www.readbyqxmd.com/read/28925706/field-effect-transistors-based-on-van-der-waals-grown-and-dry-transferred-all-inorganic-perovskite-ultrathin-platelets
#18
Chengxue Huo, Xuhai Liu, Xiufeng Song, Ziming Wang, Haibo Zeng
Nowadays, the research on perovskite transistors is still in its infancy, despite the fact that perovskite-based solar cells and light-emitting diodes have been widely investigated. Two major hurdles exist before obtaining reliable perovskite-based transistors: the processing difficulty for their sensitivity to polar solvents and unsatisfactory perovskite quality on the transistor platform. Here, for the first time, we report on high-performance all-inorganic perovskite FETs profiting from both van der Waals epitaxial boundary-free ultrathin single crystals and completely dry-processed transfer technique without chemical contaminant...
September 20, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28924567/rearrangeable-and-exchangeable-optical-module-with-system-on-chip-for-wearable-functional-near-infrared-spectroscopy-system
#19
Tsukasa Funane, Takashi Numata, Hiroki Sato, Shinsuke Hiraizumi, Yuichi Hasegawa, Hidenobu Kuwabara, Kiyoshi Hasegawa, Masashi Kiguchi
We developed a system-on-chip (SoC)-incorporated light-emitting diode (LED) and avalanche photodiode (APD) modules to improve the usability and flexibility of a fiberless wearable functional near-infrared spectroscopy (fNIRS) system. The SoC has a microprocessing unit and programmable circuits. The time division method and the lock-in method were used for separately detecting signals from different positions and signals of different wavelengths, respectively. Each module autonomously works for this time-divided-lock-in measurement with a high sensitivity for haired regions...
January 2018: Neurophotonics
https://www.readbyqxmd.com/read/28924166/determination-of-unique-power-conversion-efficiency-of-solar-cell-showing-hysteresis-in-the-i-v-curve-under-various-light-intensities
#20
Ludmila Cojocaru, Satoshi Uchida, Koichi Tamaki, Piyankarage V V Jayaweera, Shoji Kaneko, Jotaro Nakazaki, Takaya Kubo, Hiroshi Segawa
Energy harvesting at low light intensities has recently attracted a great deal of attention of perovskite solar cells (PSCs) which are regarded as promising candidate for indoor application. Anomalous hysteresis of the PSCs a complex issue for reliable evaluation of the cell performance. In order to address these challenges, we constructed two new evaluation methods to determinate the power conversion efficiencies (PCEs) of PSCs. The first setup is a solar simulator based on light emitting diodes (LEDs) allowing evaluation of the solar cells at wider range of light intensities, ranging from 10(2) to 10(-3) mW·cm(-2)...
September 18, 2017: Scientific Reports
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