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https://www.readbyqxmd.com/read/28723847/blindness-related-to-presumed-retinal-toxicity-after-using-perfluorocarbon-liquid-during-vitreoretinal-surgery
#1
Silvia Méndez-Martínez, Pilar Calvo, Nelson Arturo Rodriguez-Marco, Fernando Faus, Emilio Abecia, Luis Pablo
PURPOSE: To describe the presumed retinal toxicity after using specific batches of perfluorocarbon liquid ALA OCTA (Alamedics, Dornstadt, Germany) in pars plana vitrectomy. METHODS: This is an observational retrospective consecutive case series analyses of patients operated on pars plana vitrectomy for retinal detachment or intraocular lens subluxation, using the 150141 or 200114 batches of perfluorocarbon liquid ALA OCTA as assistance during the surgery in a single center...
July 18, 2017: Retina
https://www.readbyqxmd.com/read/28722431/giant-o2-induced-photoluminescence-modulation-in-hierarchical-titanium-dioxide-nanostructures
#2
Deborah K Pallotti, Luca Passoni, Felice Gesuele, Pasqualino Maddalena, Fabio Di Fonzo, Stefano Lettieri
We demonstrate exceptionally large modulation of PL intensity in hierarchical titanium dioxide (TiO2) nanostructures exposed to molecular oxygen (O2). Optical responsivities up to about 1100% at 20% O2 concentrations are observed in hyperbranched anatase-phase hierarchical structures, outperforming those obtainable by commercial TiO2 nanopowders (up to a factor of ∼7 for response to synthetic air) and significantly improving the ones typically reported in PL-based opto-chemical gas sensing using MOXs. The improved PL response is discussed in terms of the specific morphology of hierarchical structures, characterized by simultaneous presence of small nanoparticles, large surface areas, and large voids...
January 27, 2017: ACS Sensors
https://www.readbyqxmd.com/read/28721721/unveil-the-concentration-dependent-grain-growth-of-perovskite-films-from-one-step-and-two-step-deposition-methods-implications-for-photovoltaic-application
#3
Alison E Lewis, Yi Zhang, Peng Gao, Mohammad Khaja Nazeeruddin
In order to achieve high efficiency perovskite solar cells, understanding both the crystal structure and the opto-electronic properties of perovskite layers are of importance. This paper uses crystallization analysis and modelling study of two different perovskites deposition methods (two-step and one-step methods) and thereby shows that the one-step method embodies a film formation process that is dominated by crystal growth, while the dominant mechanism of the two-step procedure is nucleation. Our data based on the experimental and the theory shows that the one-step recipe is superior in terms of morphology control and hence the reproducibility compared to the two-step recipe...
July 19, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28720850/energy-dissipation-pathways-in-few-layer-mos2-nanoelectromechanical-systems
#4
Bernard R Matis, Brian H Houston, Jeffrey W Baldwin
Free standing, atomically thin transition metal dichalcogenides are a new class of ultralightweight nanoelectromechanical systems with potentially game-changing electro- and opto-mechanical properties, however, the energy dissipation pathways that fundamentally limit the performance of these systems is still poorly understood. Here, we identify the dominant energy dissipation pathways in few-layer MoS2 nanoelectromechanical systems. The low temperature quality factors and resonant frequencies are shown to significantly decrease upon heating to 293 K, and we find the temperature dependence of the energy dissipation can be explained when accounting for both intrinsic and extrinsic damping sources...
July 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28710993/synthesis-physicochemical-and-optical-properties-of-bis-thiosemicarbazone-functionalized-graphene-oxide
#5
Santosh Kumar, Mohmmad Y Wani, Claudia T Arranja, Ricardo A E Castro, José A Paixão, Abilio J F N Sobral
Fluorescent materials are important for low-cost opto-electronic and biomedical sensor devices. In this study we present the synthesis and characterization of graphene modified with bis-thiosemicarbazone (BTS). This new material was characterized using Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible (UV-Vis) and Raman spectroscopy techniques. Further evaluation by X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and atomic-force microscopy (AFM) allowed us to fully characterize the morphology of the fabricated material...
July 1, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28708140/wideband-tunable-opto-electronic-oscillator-based-on-frequency-translation
#6
Zeev Tamir, Asher Meltzer, Moshe Horowitz
We demonstrate a new method to obtain a widely tunable low phase-noise opto-electronic oscillator (OEO), based on translating the OEO signal into a lower intermediate frequency (IF) signal. The OEO signal is downconverted to IF by using a local oscillator (LO) signal, filtered by a high-Q filter; its frequency is then upconverted back into the high OEO frequency. The combination of a narrowband filter at a fixed central frequency with a tunable LO forms a tunable high-Q bandpass filter (BPF) that can be used to change the OEO frequency over a broad frequency region...
July 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28695740/electronic-structure-and-band-alignment-at-the-nio-and-srtio3-p-n-heterojunctions
#7
Kelvin H L Zhang, Rui Wu, Fengzai Tang, Weiwei Li, Freddy Oropeza, Liang Qiao, Vlado Lazarov, Yingge Du, David J Payne, Judith L MacManus-Driscoll, Mark Blamire
Understanding the energetics at the interface including the alignment of valence and conduction bands, built-in potentials, and ionic and electronic reconstructions, is an important challenge in designing oxide interfaces that have controllable multi-functionalities for novel (opto-)electronic devices. In this work, we report detailed investigations on the hetero-interface of wide bandgap p-type NiO and n-type SrTiO3 (STO). We show that despite a large lattice mismatch (~7%) and dissimilar crystal structure, high-quality NiO and Li doped NiO (LNO) thin films can be epitaxially grown on STO(001) substrates through a domain matching epitaxy (DME) mechanism...
July 11, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28692283/largely-improved-near-infrared-silicon-photosensing-by-the-piezo-phototronic-effect
#8
Yejing Dai, Xingfu Wang, Wenbo Peng, Haiyang Zou, Ruomeng Yu, Yong Ding, Changsheng Wu, Zhong Lin Wang
Although silicon (Si) devices are the backbone of modern (opto-)electronics, infrared Si-photosensing suffers from low-efficiency due to its limitation in light-absorption. Here, we demonstrate a large improvement in the performance, equivalent to a 366-fold enhancement in photoresponsivity, of a Si-based near-infrared (NIR) photodetector (PD) by introducing the piezo-phototronic effect via a deposited CdS layer. By externally applying a -0.15‰ compressive strain to the heterojunction, carrier-dynamics modulation at the local junction can be induced by the piezoelectric polarization, and the photoresponsivity and detectivity of the PD exhibit an enhancement of two orders of magnitude, with the peak values up to 19...
July 13, 2017: ACS Nano
https://www.readbyqxmd.com/read/28691487/low-temperature-ohmic-contact-to-monolayer-mos2-by-van-der-waals-bonded-co-h-bn-electrodes
#9
Xu Cui, En-Min Shih, Luis Angel Jauregui, Sang Hoon Chae, Young Duck Kim, Baichang Li, Dongjea Seo, Kateryna Pistunova, Jun Yin, Ji-Hoon Park, Heon-Jin Choi, Young Hee Lee, Kenji Watanabe, Takashi Taniguchi, Philip Kim, Cory R Dean, James C Hone
Monolayer MoS2, among many other transition metal dichalcogenides, holds great promise for future applications in nano-electronics and opto-electronics due to its ultra-thin nature, flexibility, sizable band-gap, and unique spin-valley coupled physics. However, careful study of these properties at low temperature has been hindered by an inability to achieve low-temperature Ohmic contacts to monolayer MoS2, particularly at low carrier densities. In this work, we report a new contact scheme that utilizes cobalt (Co) with a monolayer of hexagonal boron nitride (h-BN) which has two functions: modifies the work function of Co and acts as a tunneling barrier...
July 10, 2017: Nano Letters
https://www.readbyqxmd.com/read/28689222/insights-into-autofluorescence-patterns-in-stargardt-macular-dystrophy-using-ultra-wide-field-imaging
#10
Vinod Kumar
PURPOSE: To characterize autofluorescence (AF) patterns occurring in Stargardt macular dystrophy (STGD1) using ultra-wide-field (UWF) imaging. METHODS: This paper is a cross-sectional observational study of 22 eyes of 11 patients (mean age 23.44 years) with Stargardt disease-fundus flavimaculatus who presented with decrease of vision at a tertiary eye care center. UWF short-wave AF images were obtained from all the patients using an Optos TX200 instrument. The main outcome measures were to assess patterns of AF changes seen on UWF AF imaging...
July 8, 2017: Graefe's Archive for Clinical and Experimental Ophthalmology
https://www.readbyqxmd.com/read/28673266/ultra-widefield-fundus-imaging-in-gas-filled-eyes-after-vitrectomy
#11
Makoto Inoue, Takashi Koto, Kazunari Hirota, Akito Hirakata
BACKGROUND: To evaluate the quality of the images obtained by an ultra-widefield device in gas-filled eyes after vitrectomy for a retinal detachment. METHODS: Retrospective case series. The ultra-widefield scanning laser ophthalmoscopic images (Optos 200Tx imaging system) of 40 eyes that were gas-filled with 40 to 90% of the vitreous cavity after vitrectomy for a rhegmatogenous retinal detachment were studied. The rates of detecting the rates of reattachments and the causative retinal tears that were treated and were in the superior or inferior areas in eyes with intravitreal gas of ≥60% were compared to that to eyes with intravitreal gas of <60% of the vitreous cavity...
July 3, 2017: BMC Ophthalmology
https://www.readbyqxmd.com/read/28658323/using-c-kit-to-genetically-target-cerebellar-molecular-layer-interneurons-in-adult-mice
#12
Samantha B Amat, Matthew J M Rowan, Michael A Gaffield, Audrey Bonnan, Chikako Kikuchi, Hiroki Taniguchi, Jason M Christie
The cerebellar system helps modulate and fine-tune motor action. Purkinje cells (PCs) provide the sole output of the cerebellar cortex, therefore, any cerebellar involvement in motor activity must be driven by changes in PC firing rates. Several different cell types influence PC activity including excitatory input from parallel fibers and inhibition from molecular layer interneurons (MLIs). Similar to PCs, MLI activity is driven by parallel fibers, therefore, MLIs provide feed-forward inhibition onto PCs. To aid in the experimental assessment of how molecular layer inhibition contributes to cerebellar function and motor behavior, we characterized a new knock-in mouse line with Cre recombinase expression under control of endogenous c-kit transcriptional machinery...
2017: PloS One
https://www.readbyqxmd.com/read/28657089/enhanced-electro-active-phase-in-a-luminescent-p-vdf-hfp-zn-2-flexible-composite-film-for-piezoelectric-based-energy-harvesting-applications-and-self-powered-uv-light-detection
#13
Prakriti Adhikary, Dipankar Mandal
We have prepared a flexible polymer composite film containing poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) and Zn(2+) for the fabrication of a multifunctional piezoelectric based nanogenerator (MFNG), where a traditional electrical poling treatment was avoided. The desirable amount of Zn(2+) yields more than 99% of electro-active phases in the P(VDF-HFP) matrix that co-operates to enhance the dielectric properties of the composite film via hydrogen bonding interactions. In situ thermal Fourier transform infrared (FT-IR) spectroscopy affirms the improved thermal stability of the electro-active β-phase and the β→γ phase transition temperature in the Zn(2+) doped composite film...
July 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28651050/brillouin-oscillations-from-single-au-nanoplate-opto-acoustic-transducers
#14
Kuai Yu, Tuphan Devkota, Gary Beane, Guo Ping Wang, Gregory V Hartland
Brillouin oscillations, which are GHz frequency waves that arise from the interaction of light with acoustic waves, are experiencing increasing applications in biology and materials science. They provide information about the speed of sound and refractive index of the material they propagate in, and have recently been used in imaging applications. In the current study, Brillouin oscillations are observed through ultrafast transient reflectivity measurements using chemically synthesized Au nanoplates as opto-acoustic transducers...
June 29, 2017: ACS Nano
https://www.readbyqxmd.com/read/28649964/characterization-of-opto-electrical-enhancement-of-tandem-photoelectrochemical-cells-by-using-photoconductive-afm
#15
Sun-Young Park, Rick Elbersen, Jurriaan Huskens, Han Gardeniers, Joo-Yul Lee, Guido Mul, Jinhee Heo
Solar-to-hydrogen conversion by water splitting in photoelectrochemical cells (PECs) is a promising approach to alleviate problems associated with intermittency in solar energy supply and demand. Several interfacial resistances in photoelectrodes limit the performance of such cells, while the properties of interfaces are not easy to analyze in situ. We applied photoconductive-AFM to analyze the performance of WO3/p(+)n Si photoanodes, containing an ultra-thin metal interface of either Au or Pt. The Au interface consisted of Au nanoparticles with well-ordered interspacing, while Pt was present in the form of a continuous film...
June 26, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28640899/normative-3d-opto-electronic-stereo-photogrammetric-posture-and-spine-morphology-data-in-young-healthy-adult-population
#16
Moreno D'Amico, Edyta Kinel, Piero Roncoletta
Observational cross-sectional study. The current study aims to yield normative data: i.e., the physiological standard for 30 selected quantitative 3D parameters that accurately capture and describe a full-skeleton, upright-standing attitude. Specific and exclusive consideration was given to three distinct categories: postural, spine morphology and pelvic parameters. To capture such 3D parameters, the authors selected a non-ionising 3D opto-electronic stereo-photogrammetric approach. This required the identification and measurement of 27 body landmarks, each specifically tagged with a skin marker...
2017: PloS One
https://www.readbyqxmd.com/read/28640186/analysis-of-serotonin-molecules-on-silver-nanocolloids-a-raman-computational-and-experimental-study
#17
Felicia S Manciu, John D Ciubuc, Emma M Sundin, Chao Qiu, Kevin E Bennet
Combined theoretical and experimental analysis of serotonin by quantum chemical density functional calculations and surface-enhanced Raman spectroscopy, respectively, is presented in this work to better understand phenomena related to this neurotransmitter's detection and monitoring at very low concentrations specific to physiological levels. In addition to the successful ultrasensitive analyte detection on silver nanoparticles for concentrations as low as 10(-11) molar, the relatively good agreement between the simulated and experimentally determined results indicates the presence of all serotonin molecular forms, such as neutral, ionic, and those oxidized through redox reactions...
June 22, 2017: Sensors
https://www.readbyqxmd.com/read/28636398/ultrafast-carrier-trapping-in-thick-shell-colloidal-quantum-dots
#18
Ankit Jain, Oleksandr Voznyy, Marek Korkusinski, Pawel Hawrylak, Edward H Sargent
It has previously been found that Auger processes can lead to femtosecond carrier trapping in quantum dots, limiting their performance in optoelectronic applications that rely on radiative recombination. Using atomistic simulations, we investigate whether a shell can protect carriers from Auger-assisted trapping. For these studies we investigate CdSe/CdS core-shell quantum dots having total diameters reaching up to 10 nm. We find trapping lifetimes as fast as 1 ps for 2 nm shells, and we report that shells as thick as 6 nm are required to suppress trapping fully...
June 28, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28635643/a-multi-wavelength-opto-electronic-patch-sensor-to-effectively-detect-physiological-changes-against-human-skin-types
#19
Liangwen Yan, Sijung Hu, Abdullah Alzahrani, Samah Alharbi, Panagiotis Blanos
Different skin pigments among various ethnic group people have an impact on spectrometric illumination on skin surface. To effectively capture photoplethysmographic (PPG) signals, a multi-wavelength opto-electronic patch sensor (OEPS) together with a schematic architecture of electronics were developed to overcome the drawback of present PPG sensor. To perform a better in vivo physiological measurement against skin pigments, optimal illuminations in OEPS, whose wavelength is compatible with a specific skin type, were optimized to capture a reliable physiological sign of heart rate (HR)...
June 21, 2017: Biosensors
https://www.readbyqxmd.com/read/28632959/defect-based-modulation-of-opto-electronic-properties-for-bio-functionalized-hexagonal-boron-nitride-nanosheets
#20
Mehdi Shakourian-Fard, Hadiseh Heydari, Ganesh Kamath
Defect engineering could potentially allow for dramatic tuning of optoelectronic properties of two-dimensional materials. With the help of density functional theory (DFT) calculations, we present a systematic study of the DNA Nucleobases (NBs) adsorbed on hexagonal boron-nitride nanoflake (h-BNNF) and boron and nitrogen monovacancies. The presence of such VN and VB defects increases the binding strength of NBs by 9 kcal/mol and 34 kcal/mol, respectively (h-BNNF-VB> h-BNNF-VN> h-BNNF). A more negative electrostatic potential at the B vacancy-site makes h-BNNF-VB surface more reactive than h-BNNF-VN surface enabling H-bonding interactions with NBs...
June 20, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
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