keyword
MENU ▼
Read by QxMD icon Read
search

Light-emitting diodes

keyword
https://www.readbyqxmd.com/read/28221990/an-integrated-circuit-for-simultaneous-extracellular-electrophysiology-recording-and-optogenetic-neural-manipulation
#1
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
#2
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
#3
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
#4
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
#5
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
#6
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
#7
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
#8
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
#9
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
#10
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
#11
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
#12
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
#13
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
https://www.readbyqxmd.com/read/28208781/intelligent-luminance-control-of-lighting-systems-based-on-imaging-sensor-feedback
#14
Haoting Liu, Qianxiang Zhou, Jin Yang, Ting Jiang, Zhizhen Liu, Jie Li
An imaging sensor-based intelligent Light Emitting Diode (LED) lighting system for desk use is proposed. In contrast to the traditional intelligent lighting system, such as the photosensitive resistance sensor-based or the infrared sensor-based system, the imaging sensor can realize a finer perception of the environmental light; thus it can guide a more precise lighting control. Before this system works, first lots of typical imaging lighting data of the desk application are accumulated. Second, a series of subjective and objective Lighting Effect Evaluation Metrics (LEEMs) are defined and assessed for these datasets above...
February 9, 2017: Sensors
https://www.readbyqxmd.com/read/28207382/a-portable-brain-computer-interface-platform-for-eeg-acquisition-and-decoding
#15
Colin McCrimmon, Jonathan Fu, Ming Wang, Lucas Silva Lopes, Po Wang, Alireza Karimi-Bidhendi, Charles Liu, Payam Heydari, Zoran Nenadic, An Do
OBJECTIVE: Conventional brain-computer interfaces (BCIs) are often expensive, complex to operate, and lack portability, which confines their use to laboratory settings. Portable, inexpensive BCIs can mitigate these problems, but it remains unclear whether their low-cost design compromises their performance. Therefore, we developed a portable, low-cost BCI and compared its performance to that of a conventional BCI. METHODS: The BCI was assembled by integrating a custom electroencephalogram (EEG) amplifier with an open-source microcontroller and a touchscreen...
February 13, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28199463/effect-of-methyl-aminolevulinate-photodynamic-therapy-with-and-without-ablative-fractional-laser-treatment-in-patients-with-microinvasive-squamous-cell-carcinoma-a-randomized-clinical-trial
#16
Seung-Hwan Choi, Ki-Ho Kim, Ki-Hoon Song
Importance: Surgical excision is the standard treatment for cutaneous squamous cell carcinoma (SCC). However, microinvasive SCC (Clark level II) is limited to the papillary dermis, and it should be differentiated from invasive SCC. Ablative fractional laser-primed photodynamic therapy (AFL-PDT) may have enhanced efficacy. Objective: To compare 1 session of AFL-PDT with 2 sessions of conventional methyl aminolevulinate-PDT (MAL-PDT) for the treatment of microinvasive SCC...
February 15, 2017: JAMA Dermatology
https://www.readbyqxmd.com/read/28198804/investigating-carrier-localization-and-transfer-in-ingan-gan-quantum-wells-with-v-pits-using-near-field-scanning-optical-microscopy-and-correlation-analysis
#17
MinKwan Kim, Sunghan Choi, Joo-Hyung Lee, ChungHyun Park, Tae-Hoon Chung, Jong Hyeob Baek, Yong-Hoon Cho
The V-pits and potential fluctuations in InGaN/GaN multiple quantum wells (MQWs) are key factors for understanding the performance of InGaN/GaN-based light-emitting diodes (LEDs). However, photoluminescence (PL) measurements using conventional optical microscopy only provide ensemble information due to the spatial resolution limit, known as the diffraction barrier, which hinders the analysis of dislocations and potential fluctuations. Here, in order to investigate the influence of the V-pits and potential fluctuations on local optical properties, we performed nanoscopic luminescence mapping for standard and V-pit InGaN/GaN MQWs samples with different sized V-pits using near-field scanning optical microscopy (NSOM) with illumination mode (I-mode) at various laser excitation powers...
February 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28198432/all-nitride-alxga1-xn-mn-gan-distributed-bragg-reflectors-for-the-near-infrared
#18
Giulia Capuzzo, Dmytro Kysylychyn, Rajdeep Adhikari, Tian Li, Bogdan Faina, Aitana Tarazaga Martín-Luengo, Alberta Bonanni
Since the technological breakthrough prompted by the inception of light emitting diodes based on III-nitrides, these material systems have emerged as strategic semiconductors not only for the lighting of the future, but also for the new generation of high-power electronic and spintronic devices. While III-nitride optoelectronics in the visible and ultraviolet spectral range is widely established, all-nitride efficient devices in the near-infrared (NIR) are still wanted. Here, through a comprehensive protocol of design, modeling, epitaxial growth and in-depth characterization, we develop AlxGa1-xN:Mn/GaN NIR distributed Bragg reflectors and we show their efficiency in combination with GaN:(Mn,Mg) layers containing Mn-Mgk complexes optically active in the near-infrared range of wavelengths...
February 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28198107/fluorescent-supramolecular-polymeric-materials
#19
REVIEW
Hu Wang, Xiaofan Ji, Zhengtao Li, Feihe Huang
Fluorescent supramolecular polymeric materials are rising stars in the field of fluorescent materials not only because of the inherent optoelectronic properties originating from their chromophores, but also due to the fascinating stimuli-responsiveness and reversibility coming from their noncovalent connections. Especially, these noncovalent connections influence the fluorescence properties of the chromophores because their state of aggregation and energy transfer can be regulated by the assembly-disassembly process...
February 15, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28195844/the-efficacy-and-safety-of-660-nm-and-411-to-777-nm-light-emitting-devices-for-treating-wrinkles
#20
Chan Hee Nam, Byung Cheol Park, Myung Hwa Kim, Eun Hee Choi, Seung Phil Hong
BACKGROUND: Low-level light therapy (LLLT) using light-emitting diodes (LEDs) is considered to be helpful for skin regeneration and anti-inflammation. OBJECTIVE: To evaluate the efficacy and safety of 2 types of LLLTs using 660 nm-emitting red LEDs and 411 to 777 nm-emitting white LEDs in the treatment of facial wrinkles. MATERIALS AND METHODS: A prospective, randomized, double-blinded, comparative clinical trial involving 52 adult female subjects was performed...
February 9, 2017: Dermatologic Surgery: Official Publication for American Society for Dermatologic Surgery [et Al.]
keyword
keyword
11224
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"