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https://www.readbyqxmd.com/read/28821127/a-comparative-study-on-cellulose-nanocrystals-extracted-from-bleached-cotton-and-flax-and-used-for-casting-films-with-glycerol-and-sorbitol-plasticisers
#1
Emilia Csiszár, Sebestyén Nagy
Cellulose nanocrystals (CNCs) were released from bleached cotton and flax by a sulphuric acid hydrolysis with about 40 and 34% yield, respectively. The rod-like cotton-CNC particles were slightly longer and wider and had a less pronounced aggregation ability in aqueous suspension than the flax-CNC ones. Films were cast from the CNC suspensions with sorbitol and glycerol plasticisers. The concept behind this research was to explore how the plasticisers - with similar structure but different molecular weight - and their concentrations affect the perceptible and measured properties of CNC films...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821101/cholesteric-film-of-cu-ii-doped-cellulose-nanocrystals-for-colorimetric-sensing-of-ammonia-gas
#2
Shidong Dai, Nana Prempeh, Dagang Liu, Yimin Fan, Mingyue Gu, Yu Chang
With the increasing demand of environmental monitoring for toxic and odorous ammonia gas it is desired to develop specific green, cost-effective and in situ passive colorimetric alternatives to current complex instrumentations. In this work, we designed an ammonia gas sensor based on cholesteric liquid crystal films of copper(II)-doped cellulose nanocrystals (CNCCu(II)) whose structure, optical and sensing properties were investigated. The hybrid films using the low doping Cu(II) as a color-tuning agent inherited the chiral nematic signature and optical activity of CNCs, suggesting a strong chelation between copper ions and negatively charged CNCs...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821083/vapor-sensing-with-color-tunable-multilayered-coatings-of-cellulose-nanocrystals
#3
Yu Zhao, Guizhi Gao, Dagang Liu, Donglin Tian, Yinyan Zhu, Yu Chang
Colloidal cellulose nanocrystals were LBL deposited to form firmly-stacked optical coatings in which the nanorods regulated their head-to-tail association and aligned in the axial-centrifuged direction. The periodically transition from blue to orange of reflected colors was tunable via deposition layer adjustment. While the sensing coating was exposed to vapors of NH3(.)H2O, H2O, HCl and HAc, respectively, the color variation in the response process was irreversible at room temperature and highly dependent on vapor diffusion and chemical interface interaction...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821075/rapid-fabrication-of-transparent-film-directly-from-wood-fibers-with-microwave-assisted-ionic-liquids-technology
#4
Pengbo Lu, Fan Cheng, Yanghao Ou, Meiyan Lin, Lingfeng Su, Size Chen, Xilang Yao, Detao Liu
Presently flexibly transparent film or nanopaper from all cellulose was mostly fabricated by assembling cellulose nanofibers disintegrated from macroscopic wood fibers which mostly suffers from potential environmental toxicity or high cost. In this work, we firstly reported an all-cellulose transparent film fabricated by a novel microwave-assisted ionic liquids technology (MILT). The use of MILT for treating the original all-cellulose paper brings nearly 2.6 fold-increases in optical transmission, and 2.0 fold-increases in tensile property compared to those without microwave assistance...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821051/a-novel-self-assembly-lentinan-tetraphenylethylene%C3%A2-composite-with-strong-blue%C3%A2-fluorescence-in-water-and-its-properties
#5
Mengxia Li, Pan Chen, Min Xu, Xiaojuan Xu
We report a unique self-assembly of lentinan, a triple helical β-(1→3)-glucan (t-LNT), in water. By molecular dynamics simulation, it was found that t-LNT aggregated preferentially along the chain direction to form long chains, accompanied by side-direction linkage to form branches. Transmission electron microscopy images demonstrated that t-LNT formed dendrite-like fibers, which further formed fishnet-like porous/mesoporous aggregates with increasing concentration. The meshes in the fishnet were ascribed to the intersection of branches...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821041/regulation-of-structure-rheological-and-surface-properties-of-chitin-nanocrystal-dispersions
#6
M A Torlopov, I S Martakov, V I Mikhaylov, N V Tsvetkov, P V Krivoshapkin
The hydrosols of chitin nanocrystals (ChN) are promising as modifiers of properties, drug delivery systems, and media. The purpose of this work is to clarify the mechanisms for regulating processes of stability and structure formation occurring in the ChN hydrosols under the influence of varying ionic strength. ChN were isolated from the crab shell; ChN hydrosols are obtained with different concentrations of the dispersed phase. The structure and morphology of the particles was studied by atomic force microscopy and X-ray diffraction...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28820937/impact-of-shell-thickness-on-photoluminescence-and-optical-activity-in-chiral-cdse-cds-core-shell-quantum-dots
#7
Finn Purcell-Milton, Anastasia K Visheratina, Vera A Kuznetsova, Aisling Ryan, Anna O Orlova, Yurii K Gun'ko
Core/Shell quantum dots (QDs) are of high scientific and technological importance as these nanomaterials have found a number of valuable applications. In this paper, we have investigated the dependence of optical activity and photoluminescence upon CdS shell thickness in a range of core-shell structured CdSe/CdS QDs capped with chiral ligands. For our study, five samples of CdSe/CdS were synthesised utilizing successive ion layer adsorption and reaction (SILAR) to vary the thickness of the CdS shell from 0...
August 18, 2017: ACS Nano
https://www.readbyqxmd.com/read/28820932/titanium-oxynitride-thin-films-with-tuneable-double-epsilon-near-zero-behaviour-for-nanophotonic-applications
#8
Laurentiu Braic, Nikolaos Vasilantonakis, Andrei Mihai, Ignacio Jose Villar-Garcia, Sarah Fearn, Bin Zou, Neil McN Alford, Brock Doiron, Rupert F Oulton, Stefan A Maier, Anatoly V Zayats, Peter K Petrov
Titanium Oxynitride (TiOxNy) thin films are fabricated using reactive magnetron sputtering. The mechanism of their growth formation is explained and their optical properties are presented. The films grown when the level of residual Oxygen in the background vacuum was between 5 nTorr to 20 nTorr exhibit double Epsilon-Near- Zero (2-ENZ) behaviour with ENZ1 and ENZ2 wavelengths tunable in the 700-850 nm and in the 1100-1350 nm spectral ranges, respectively. Samples fabricated when the level of residual Oxygen in the background vacuum was above 2E-8Torr exhibit non- metallic behaviour, while the layers deposited when the level of residual Oxygen in the background vacuum was below 5E-9Torr, show metallic behaviour with a single ENZ value...
August 18, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28820921/analysis-of-cone-mosaic-reflectance-properties-in-healthy-eyes-and-in-eyes-with-nonproliferative-diabetic-retinopathy-over-time
#9
Letizia Mariotti, Nicholas Devaney, Giuseppe Lombardo, Marco Lombardo
Purpose: We investigate the reflectance properties of the cone mosaic in adaptive optics (AO) images of healthy subjects and subjects with nonproliferative diabetic retinopathy (NPDR) over time. Methods: We acquired images of the parafoveal cone mosaic over 5 years in 12 healthy subjects and in six patients with mild NPDR. We analyzed the parameters of the cone intensity histogram distribution (mean, SD, and skewness), two metrics of the cone mosaic texture (sharpness and entropy), and two novel metrics (cone/intercone intensity and slope of the variogram)...
August 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28820864/diffusion-kurtosis-imaging-and-pathology-in-spinal-cord-ischemia-reperfusion-injury-in-rabbits-a-case-control-study
#10
Daowei Li, Xiaoming Wang
BACKGROUND The aim of this study was to evaluate the application of diffusion kurtosis imaging (DKI) in spinal cord ischemia/reperfusion (SCI/R) injury and to explore its association with pathology. MATERIAL AND METHODS Japanese male long-eared rabbits were chosen and divided into 7 groups (8 rabbits in each group): control group (C group), sham-operation control group (S group), and 5 experimental groups (E-2 h group, E-24 h group, E-48 h group, E-7 d group, and E-14 d group). Tarlov scoring and immunohistochemical staining were used to assess hindlimb motor function and observe the expression of glial fiber acidic protein (GFAP), respectively...
August 18, 2017: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
https://www.readbyqxmd.com/read/28820764/severe-case-of-renal-coloboma-syndrome-in-long-term-follow-up
#11
Lise Sels, Werner Dirven, Koenraad Devriendt, Anita Leys
PURPOSE: To characterize the ocular features of a severe case of renal coloboma syndrome in a long-term follow-up. METHODS: Observational case report over a period of 45 years. Examination under anesthesia at the age of 3 months, repeated ophthalmologic examination (age 7, 14, 25, 45 years), fluorescein and indocyanine green angiography, electroretinography, ocular ultrasound, optical coherence tomography, computed tomography scan orbits, and magnetic resonance imaging of the brain...
August 17, 2017: Retinal Cases & Brief Reports
https://www.readbyqxmd.com/read/28820744/simulation-of-morphologically-structured-photo-thermal-neural-stimulation
#12
Y Weissler, N Farah, S Shoham
OBJECTIVE: Rational design of next-generation techniques for photo-thermal excitation requires the development of tools capable of modeling the effects of spatially- and temporally-dependent temperature distribution on cellular neuronal structures. APPROACH: We present a new computer simulation tool for predicting the effects of arbitrary spatiotemporally-structured photo-thermal stimulation on 3D, morphologically realistic neurons. The new simulation tool is based on interfacing two generic platforms, NEURON and MATLAB and is therefore suited for capturing different kinds of stimuli and neural models...
August 18, 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28820741/electromagnetic-and-optical-characteristics-of-nb5-doped-double-crossover-and-salmon-dna-thin-films
#13
Mitta Sekhar Babu, Sreekantha Reddy Dugasani, Soon-Gil Jung, Srivithya Vellampatti, Tuson Park, Sung Ha Park
We report the fabrication and physical characteristics of niobium ion (Nb5+)-doped double-crossover DNA (DX-DNA) and salmon DNA (SDNA) thin films. Different concentrations of Nb5+ ([Nb5+]) are coordinated into the DNA molecules, and the thin films are fabricated via substrate-assisted growth (DX-DNA) and drop-casting (SDNA) on oxygen plasma treated substrates. We conducted atomic force microscopy to estimate the optimum concentration of Nb5+ ([Nb5+]O = 0.08 mM) in Nb5+-doped DX-DNA thin films, up to which the DX-DNA lattices maintain their structures without deformation...
August 18, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28820649/targets-of-neuroprotection-in-glaucoma
#14
Shaoqing He, Dorota L Stankowska, Dorette Z Ellis, Raghu R Krishnamoorthy, Thomas Yorio
Progressive neurodegeneration of the optic nerve and the loss of retinal ganglion cells is a hallmark of glaucoma, the leading cause of irreversible blindness worldwide, with primary open-angle glaucoma (POAG) being the most frequent form of glaucoma in the Western world. While some genetic mutations have been identified for some glaucomas, those associated with POAG are limited and for most POAG patients, the etiology is still unclear. Unfortunately, treatment of this neurodegenerative disease and other retinal degenerative diseases is lacking...
August 18, 2017: Journal of Ocular Pharmacology and Therapeutics
https://www.readbyqxmd.com/read/28820625/multimodal-image-analysis-of-the-retina-in-hunter-syndrome-mucopolysaccharidosis-type-ii-case-report
#15
Isadora Darriba Macedo Salvucci, Simone Finzi, Maria Kiyoko Oyamada, Chong Ae Kim, Sérgio Luis Gianotti Pimentel
INTRODUCTION: We report a case of retinal and posterior ocular findings in a 33-year-old man diagnosed with Hunter syndrome (Mucopolysaccharidosis type II) in a multimodal imaging way. CASE PRESENTATION: Our patient was complaining of blurred night vision for the past 3 years. He had not received any systemic treatment for Hunter syndrome. Vision acuity was 20/20 in both eyes and corneas were clear. Fundus examination revealed bilateral crowded and hyperemic optic nerve heads (elevated in the ocular ultrasound) and areas of subretinal hypopigmentation...
August 18, 2017: Ophthalmic Genetics
https://www.readbyqxmd.com/read/28820624/retinopathy-and-optic-atrophy-expanding-the-phenotypic-spectrum-of-pathogenic-variants-in-the-aars2-gene
#16
Jason H Peragallo, Stephanie Keller, Marjo S van der Knaap, Bruno P Soares, Suma P Shankar
BACKGROUND: Optic atrophy may be the sequela of optic nerve injury due to any insult, including isolated and syndromic genetic diseases. Alanyl-tRNA synthetase 2 (AARS2) pathogenic variants have been reported to cause leukodystrophy with ovarian failure, and cardiomyopathy (#615889) as well as combined oxidative phosphorylation deficiency-8 (#614096). We report a young child who presented with decreased vision due to optic atrophy and was found to harbor missense variants in the AARS2 gene expanding the phenotypic expression of the AARS2 gene...
August 18, 2017: Ophthalmic Genetics
https://www.readbyqxmd.com/read/28820602/intricate-resonant-raman-response-in-anisotropic-res2
#17
Amber McCreary, Jeffrey R Simpson, Yuanxi Wang, Daniel Rhodes, Kazunori Fujisawa, Luis Balicas, Madan Dubey, Vincent H Crespi, Mauricio Terrones, Angela R Hight Walker
The strong in-plane anisotropy of rhenium disulfide (ReS2) offers an additional physical parameter that can be tuned for advanced applications such as logic circuits, thin-film polarizers, and polarization-sensitive photodetectors. ReS2 also presents advantages for optoelectronics, as it is both a direct-gap semiconductor for few-layer thicknesses (unlike MoS2 or WS2) and stable in air (unlike black phosphorus). Raman spectroscopy is one of the most powerful characterization techniques to non-destructively and sensitively probe the fundamental photo-physics of a 2D material...
August 18, 2017: Nano Letters
https://www.readbyqxmd.com/read/28820601/negatively-charged-and-dark-excitons-in-cspbbr3-perovskite-nanocrystals-revealed-by-high-magnetic-fields
#18
Damien Canneson, Elena V Shornikova, Dmitri R Yakovlev, Tobias Rogge, Anatolie A Mitioglu, Mariana V Ballottin, Peter C M Christianen, Emmanuel Lhuillier, Manfred Bayer, Louis Biadala
The optical properties of colloidal cesium lead halide perovskite (CsPbBr3) nanocrystals are examined by time-resolved and polarization-resolved spectroscopy in high magnetic fields up to 30 T. We unambiguously show that at cryogenic temperatures the emission is dominated by recombination of negatively charged excitons with radiative decay time of 300 ps. The additional long-lived emission with a decay time of 10-30 ns, which decay time shortens and relative amplitude increases in high magnetic fields, evidence the presence of a dark exciton...
August 18, 2017: Nano Letters
https://www.readbyqxmd.com/read/28820599/optical-gating-of-black-phosphorus-for-thz-detection
#19
Martin Mittendorff, Ryan J Suess, Edward Leong, Thomas E Murphy
Photoconductive antennas are widely used for time-resolved detection of THz pulses. In contrast to photothermoelectric or bolometric THz detection, the coherent detection allows direct measurement of the electric field transient of a THz pulse, which contains both, spectral and phase information. In this letter we demonstrate for the first time photoconductive detection of free-space propagating THz radiation with thin flakes of a van der Waals material. Mechanically exfoliated flakes of black phosphorus are combined with an antenna that concentrates the THz fields to the small flake (~10 μm)...
August 18, 2017: Nano Letters
https://www.readbyqxmd.com/read/28820597/deterministic-symmetry-breaking-of-plasmonic-nanostructures-enabled-by-dna-programmable-assembly
#20
Matthew R Jones, Kevin L Kohlstedt, Matthew N O'Brien, Jinsong Wu, George C Schatz, Chad A Mirkin
The physical properties of matter rely fundamentally on the symmetry of constituent building blocks. This is particularly true for structures that interact with light via the collective motion of their conduction electrons (i.e., plasmonic materials), where the observation of exotic optical effects, such as negative refraction and electromagnetically induced transparency, require the coupling of modes that are only present in systems with nontrivial broken symmetries. Lithography has been the predominant fabrication technique for constructing plasmonic metamaterials, as it can be used to form patterns of arbitrary complexity, including those with broken symmetry...
August 18, 2017: Nano Letters
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