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https://www.readbyqxmd.com/read/28231432/dismantling-the-red-wall-of-colloidal-perovskites-highly-luminescent-formamidinium-and-formamidinium-cesium-lead-iodide-nanocrystals
#1
Loredana Protesescu, Sergii Yakunin, Sudhir Kumar, Janine Bär, Federica Bertolotti, Norberto Masciocchi, Antonietta Guagliardi, Matthias Grotevent, Ivan Shorubalko, Maryna I Bodnarchuk, Chih-Jen Shih, Maksym V Kovalenko
Colloidal nanocrystals (NCs) of APbX3-type lead halide perovskites [A=Cs+, CH3NH3+ (methylammonium or MA+) or CH(NH2)2+ (formamidinium or FA+); X=Cl-, Br-, I-] have recently emerged as highly versatile photonic sources for applications ranging from simple photoluminescence down-conversion (e.g., for display backlighting) to light emitting diodes. From the perspective of spectral coverage, a formidable challenge facing the use of these materials is how to obtain stable emissions in the red and infrared spectral regions covered by the iodide-based compositions...
February 23, 2017: ACS Nano
https://www.readbyqxmd.com/read/28231069/the-potential-of-transcranial-photobiomodulation-therapy-for-treatment-of-major-depressive-disorder
#2
Farzad Salehpour, Seyed Hossein Rasta
Major depressive disorder is a common debilitating mood disorder that affects quality of life. Prefrontal cortex abnormalities, an imbalance in neurotransmitters, neuroinflammation, and mitochondrial dysfunction are the major factors in the etiology of major depressive disorder. Despite the efficacy of pharmacotherapy in the treatment of major depressive disorder, 30%-40% of patients do not respond to antidepressants. Given this, exploring the alternative therapies for treatment or prevention of major depressive disorder has aroused interest among scientists...
February 23, 2017: Reviews in the Neurosciences
https://www.readbyqxmd.com/read/28227495/vibrocv-a-computer-vision-based-vibroarthrography-platform-with-possible-application-to-juvenile-idiopathic-arthritis
#3
Andrew D Wiens, Sampath Prahalad, Omer T Inan, Andrew D Wiens, Sampath Prahalad, Omer T Inan, Andrew D Wiens, Omer T Inan, Sarnpath Prahalad
Vibroarthrography, a method for interpreting the sounds emitted by a knee during movement, has been studied for several joint disorders since 1902. However, to our knowledge, the usefulness of this method for management of Juvenile Idiopathic Arthritis (JIA) has not been investigated. To study joint sounds as a possible new biomarker for pediatric cases of JIA we designed and built VibroCV, a platform to capture vibroarthrograms from four accelerometers; electromyograms (EMG) and inertial measurements from four wireless EMG modules; and joint angles from two Sony Eye cameras and six light-emitting diodes with commercially-available off-the-shelf parts and computer vision via OpenCV...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227150/integration-of-optical-and-electrochemical-sensors-on-a-microfluidic-platform-using-organic-optoelectronic-components-and-silver-nanowires
#4
Sujittra Poorahong, Florent Lefevre, Marie-Claude Perron, Philippe Juneau, Ricardo Izquierdo, Sujittra Poorahong, Florent Lefevre, Marie-Claude Perron, Philippe Juneau, Ricardo Izquierdo, Sujittra Poorahong, Ricardo Izquierdo, Florent Lefevre, Philippe Juneau, Marie-Claude Perron
Since the emergence of microfluidic platforms sensors integration has been a major challenge. With the advances in miniaturization of these platforms, there is a need for solutions to integrate various optical components in order to build sensors, which will offer different detection characteristics such as several emission and sensing wavelengths. Moreover, the integration of an electrochemical sensor including a transparent electrode that will be compatible with the optical sensor represents an additional challenge...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226914/sticker-type-ecg-ppg-concurrent-monitoring-system-hybrid-integration-of-cmos-soc-and-organic-sensor-device
#5
Yongsu Lee, Hyeonwoo Lee, Seunghyup Yoo, Hoi-Jun Yoo, Yongsu Lee, Hyeonwoo Lee, Seunghyup Yoo, Hoi-Jun Yoo, Seunghyup Yoo, Yongsu Lee, Hoi-Jun Yoo, Hyeonwoo Lee
The sticker-type sensor system is proposed targeting ECG/PPG concurrent monitoring for cardiovascular diseases. The stickers are composed of two types: Hub and Sensor-node (SN) sticker. Low-power CMOS SoC for measuring ECG and PPG signal is hybrid integrated with organic light emitting diodes (OLEDs) and organic photo detector (OPD). The sticker has only 2g weight and only consumes 141μW. The optical calibration loop is adopted for maintaining SNR of PPG signal higher than 30dB. The pulse arrival time (PAT) and SpO2 value can be extracted from various body parts and verified comparing with the reference device from 20 people in-vivo experiments...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28225028/stacking-multiple-connecting-functional-materials-in-tandem-organic-light-emitting-diodes
#6
Tao Zhang, Deng-Ke Wang, Nan Jiang, Zheng-Hong Lu
Tandem device is an important architecture in fabricating high performance organic light-emitting diodes and organic photovoltaic cells. The key element in making a high performance tandem device is the connecting materials stack, which plays an important role in electric field distribution, charge generation and charge injection. For a tandem organic light-emitting diode (OLED) with a simple Liq/Al/MoO3 stack, we discovered that there is a significant current lateral spreading causing light emission over an extremely large area outside the OLED pixel when the Al thickness exceeds 2 nm...
February 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28222599/petal-inspired-diffractive-grating-on-a-wavy-surface-deterministic-fabrications-and-applications-to-colorizations-and-led-devices
#7
Kyung Jin Park, Jae Hoon Park, Ji-Hyeok Huh, Chan Ho Kim, Dong Hae Ho, Gwan H Choi, Pil J Yoo, Sung Min Cho, Jeong Ho Cho, Seungwoo Lee
Interestingly, the petals of flowering plants display unique hierarchical structures, in which surface relief gratings (SRGs) are conformably coated on a curved surface with a large radius of curvature (hereafter referred to as wavy surface). However, systematic studies on the interplay between the diffractive modes and the wavy surface have not yet been reported, due to the absence of deterministic nanofabrication methods capable of generating combinatorially diverse SRGs on a wavy surface. Here, by taking advantage of the recently developed nanofabrication composed of evaporative assembly and photofluidic holography inscription, we were able to achieve (i) combinatorially diverse petal-inspired SRGs with controlled curvatures, periodicities, and dimensionalities, and (ii) systematic optical studies of the relevant diffraction modes...
February 22, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28221990/an-integrated-circuit-for-simultaneous-extracellular-electrophysiology-recording-and-optogenetic-neural-manipulation
#8
Chang Hao Chen, Elizabeth A McCullagh, Sio Hang Pun, Peng Un Mak, Mang I Vai, Pui In Mak, Achim Klug, Tim C Lei
OBJECTIVE: The ability to record and to control action potential firing in neuronal circuits is critical to understand how the brain functions. The objective of this study is to develop a monolithic integrated circuit (IC) to record action potentials and simultaneously control action potential firing using optogenetics. METHODS: A low-noise and high input impedance (or low input capacitance) neural recording amplifier is combined with a high current laser/light-emitting diode (LED) driver in a single IC...
March 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28221904/reduction-of-bacterial-pathogens-and-potential-surrogates-on-the-surface-of-almonds-using-high-intensity-405-nanometer-light
#9
Alison Lacombe, Brendan A Niemira, Joseph Sites, Glenn Boyd, Joshua B Gurtler, Breanna Tyrell, Melissa Fleck
The disinfecting properties of high-intensity monochromatic blue light (MBL) were investigated against Escherichia coli O157:H7, Salmonella , and nonpathogenic bacteria inoculated onto the surface of almonds. MBL was generated from an array of narrow-band 405-nm light-emitting diodes. Almonds were inoculated with higher or lower levels (8 or 5 CFU/g) of pathogenic E. coli O157:H7 and Salmonella , as well as nonpathogenic E. coli K-12 and an avirulent strain of Salmonella Typhimurium, for evaluation as potential surrogates for their respective pathogens...
November 2016: Journal of Food Protection
https://www.readbyqxmd.com/read/28221029/highly-efficient-and-thermally-stable-k3alf6-mn4-as-a-red-phosphor-for-ultra-high-performance-warm-white-leds
#10
Enhai Song, Jianqing Wang, Jiahao Shi, Tingting Deng, Shi Ye, Mingying Peng, Jing Wang, Lothar Wondraczek, Qinyuan Zhang
Following pioneering work, solution-processable Mn4+-activated fluoride pigments, such as A2BF6 (A = Na, K, Rb, Cs; A2 = Ba, Zn; B = Si, Ge, Ti, Zr, Sn), have attracted considerable attention as highly promising red phosphors for warm white light emitting diodes (W-LEDs). To date, these fluoride pigments have been synthesized via traditional chemical routes with HF-solution. However, in addition to the possible dangers of hypertoxic HF, the uncontrolled precipitation of fluorides and the extensive processing steps produce large morphological variations, resulting in a wide variation in the LED performance of the resulting devices, which hampers their prospects for practical applications...
February 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28220661/tunable-luminescence-and-energy-transfer-in-ca3-sio4-cl2-ce-3-li-mn-2-eu-2-phosphors
#11
Xiangqi Li, Xiuzhen Xie, Haiting Wei, Minzhen Zhong
A series of color-tunable Ca3-2x-y-z SiO4 Cl2 (CSC):xCe(3+) ,xLi(+) ,yMn(2+) ,zEu(2+) phosphors with low temperature phase structure was synthesized via the sol-gel method. An energy transfer process from Ce(3+) to Mn(2+) in CSC:0.01Ce(3+) ,0.01Li(+) ,yMn(2+) (y = 0.03-0.09) and the mechanism was verified to be an electric dipole-dipole interaction. The Ce(3+) and Mn(2+) emission intensities were greatly enhanced by co-doping Eu(2+) ions into CSC:0.01Ce(3+) ,0.01Li(+) ,0.07Mn(2+) phosphors due to competitive energy transfers from Eu(2+) /Ce(3+) to Mn(2+) , and Ce(3+) to Eu(2+) ...
February 21, 2017: Luminescence: the Journal of Biological and Chemical Luminescence
https://www.readbyqxmd.com/read/28218704/an-easy-approach-to-control-%C3%AE-phase-formation-in-pfo-films-for-optimized-emission-properties
#12
Qi Zhang, Lang Chi, Gang Hai, Yueting Fang, Xiangchun Li, Ruidong Xia, Wei Huang, Erdan Gu
We demonstrate a novel approach to control β-phase content generated in poly(9,9-dioctylfluorene) (PFO) films. A very small amount of paraffin oil was used as the additive to the PFO solution in toluene. The β-phase fraction in the spin-coated PFO films can be modified from 0% to 20% simply by changing the volume percentage of paraffin oil in the mixed solution. Organic light emitting diodes (OLEDs) and amplified spontaneous emission (ASE) study confirmed low β-phase fraction promise better OLEDs device, while high β-phase fraction benefits ASE performance...
February 18, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28218516/coumarin-based-thermally-activated-delayed-fluorescence-emitters-with-high-external-quantum-efficiency-and-low-efficiency-roll-off-in-the-devices
#13
Jia-Xiong Chen, Wei Liu, Cai-Jun Zheng, Kai Wang, Ke Liang, Yizhong Shi, Xue-Mei Ou, Xiao-Hong Zhang
Thermally activated delayed fluorescence (TADF) emitters have attracted much interest for their great applications in organic light emitting diodes (OLEDs), but the TADF OLEDs are limited by large efficiency roll-offs. In this study, we report two coumarin-based TADF emitters, 3-methyl-6-(10H-phenoxazin-10-yl)-1H-isochromen-1-one (PHzMCO) and 9-(10H-phenoxazin-10-yl)-6H-benzo[c]chromen-6-one (PHzBCO), with relatively high photoluminescence quantum yields (PLQYs) and extremely small singlet-triplet splittings...
February 20, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28218246/organic-organic-heterointerface-engineering-to-boost-carrier-injection-in-oleds
#14
Mohammadreza Fathollahi, Mohsen Ameri, Ezeddin Mohajerani, Ebrahim Mehrparvar, Mohammadrasoul Babaei
We investigate dynamic formation of nanosheet charge accumulations by heterointerface engineering in double injection layer (DIL) based organic light emitting diodes (OLEDs). Our experimental results show that the device performance is considerably improved for the DIL device as the result of heterointerface injection layer (HIIL) formation, in comparison to reference devices, namely, the current density is doubled and even quadrupled and the turn-on voltage is favorably halved, to 3.7 V, which is promising for simple small-molecule OLEDs...
February 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28216605/an-overview-of-stress-induced-resveratrol-synthesis-in-grapes-perspectives-for-resveratrol-enriched-grape-products
#15
REVIEW
Mohidul Hasan, Hanhong Bae
Resveratrol is the most important stilbene phytoalexin synthesized naturally or induced in plants, as a part of their defense mechanism. Grapes and their derivative products, including juice and wine, are the most important natural sources of resveratrol, consisting of notably higher amounts than other natural sources like peanuts. Consumption of red wine with its presence of resveratrol explained the "French Paradox". Hence, the demand of resveratrol from grapes is increasing. Moreover, as a natural source of resveratrol, grapes became very important in the nutraceutical industry for their benefits to human health...
February 14, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28215607/impact-of-blue-red-and-far-red-light-treatments-on-gene-expression-and-steviol-glycoside-accumulation-in-stevia-rebaudiana
#16
Yuki Yoneda, Hiroshi Nakashima, Juro Miyasaka, Katsuaki Ohdoi, Hiroshi Shimizu
Stevia rebaudiana (Bertoni) Bertoni is a plant that biosynthesizes a group of natural sweeteners that are up to approximately 400 times sweeter than sucrose. The sweetening components of S. rebaudiana are steviol glycosides (SGs) that partially share their biosynthesis pathway with gibberellins (GAs). However, the molecular mechanisms through which SGs levels can be improved have not been studied. Therefore, transcription levels of several SG biosynthesis-related genes were analyzed under several light treatments involved in GA biosynthesis...
February 15, 2017: Phytochemistry
https://www.readbyqxmd.com/read/28214745/rapid-detection-and-quantification-of-enterovirus-71-by-a-portable-surface-plasmon-resonance-biosensor
#17
Briliant Adhi Prabowo, Robert Y L Wang, Muhammad Khari Secario, Po-Ting Ou, Azharul Alom, Jia-Jung Liu, Kou-Chen Liu
This study presents the first report on a label-free detection and rapid quantification method for human enterovirus 71 (EV71) using a portable surface plasmon resonance (SPR) system. The SPR sensor instrument was configured to run on low power in a miniaturized platform to improve the device portability for a wider application both in laboratories and in the field. A color tunable organic light emitting diode in red spectrum was attached on a trapezoidal prism for the disposable light source module. The SPR signal processing using integration area under the reflectivity curve is applied for optimum signal to noise ratio (SNR) enhancement...
January 21, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28213900/c-h-direct-arylated-6h-indolo-2-3-b-quinoxaline-derivative-as-thickness-dependent-hole-injection-layer
#18
Dai Dong, Da Fang, Hairong Li, Caixia Zhu, Xianghua Zhao, Jiewei Li, Lingzhi Jin, Linghai Xie, Lin Chen, Jianfeng Zhao, Hongmei Zhang, Wei Huang
A novel perfluoro-1,4-phenylenyl 6H-indolo[2,3-b]quinoxaline derivative (TFBIQ) was designed and synthesized via C-H direct arylation. The opto-electrical properties of the obtained TFBIQ were fully characterized by UV-vis and photoluminescence, cyclic voltammetry, film morphology and Alq3-based green organic light emitting diodes (OLEDs). Device A using 0.5 nm thick TFBIQ as the interfacial modification layer exhibits the best five advantages of device performance including the lowest minimum turn-on voltage (Von) as low as 3...
February 18, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/28213248/multi-reverse-flow-injection-analysis-integrated-with-multi-optical-sensor-for-simultaneous-determination-of-mn-ii-fe-ii-cu-ii-and-fe-iii-in-natural-waters
#19
Napaporn Youngvises, Kittigan Suwannasaroj, Jaroon Jakmunee, Awadh AlSuhaimi
Multi-reverse flow injection analysis (Mr-FIA) integrated with multi-optical sensor was developed and optimized for the simultaneous determination of multi ions; Mn(II), Fe(II), Cu(II) and Fe(III) in water samples. The sample/standard solutions were propelled making use of a four channels peristaltic pump whereas 4 colorimetric reagents specific for the metal ions were separately injected in sample streams using multi-syringe pump. The color zones that formed in the individual mixing coils were then streamed into multi-channels spectrometer, which comprised of four flows through cell and four pairs of light emitting diode and photodiode, whereby signals were measured concurrently...
May 1, 2017: Talanta
https://www.readbyqxmd.com/read/28211516/high-efficient-oled-displays-prepared-with-the-air-gapped-bridges-on-quantum-dot-patterns-for-optical-recycling
#20
Hyo-Jun Kim, Min-Ho Shin, Joo-Suc Kim, Se-Eun Kim, Young-Joo Kim
An optically efficient structure was proposed and fabricated to realize high brightness organic light emitting diode (OLED) displays based on a white OLED prepared with the air-gapped bridges on the quantum dot (QD) patterns. Compared with a conventional white OLED display, in our experiments, the optical intensity of the proposed OLED display shows the enhancement of 58.2% in the red color and 16.8% in the green color after applying the air-gapped bridge structure on QD patterns of 20 wt% concentration. This enhancement comes from the two facts that the QD patterns downconvert unnecessary blue or blue/green light to the required green or red light and the air-gapped bridges increase the color conversion efficiency of QDs by optical recycling using total internal reflection (TIR) at the interface...
February 17, 2017: Scientific Reports
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