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https://www.readbyqxmd.com/read/28655220/self-catalyzed-growth-of-vertical-gasb-nanowires-on-inas-stems-by-metal-organic-chemical-vapor-deposition
#1
Xianghai Ji, Xiaoguang Yang, Tao Yang
We report the first self-catalyzed growth of high-quality GaSb nanowires on InAs stems using metal-organic chemical vapor deposition (MOCVD) on Si (111) substrates. To achieve the growth of vertical InAs/GaSb heterostructure nanowires, the two-step flow rates of the trimethylgallium (TMGa) and trimethylantimony (TMSb) are used. We first use relatively low TMGa and TMSb flow rates to preserve the Ga droplets on the thin InAs stems. Then, the flow rates of TMGa and TMSb are increased to enhance the axial growth rate...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28654886/bimetallic-pt-au-nanocatalysts-electrochemically-deposited-on-boron-doped-diamond-electrodes-for-nonenzymatic-glucose-detection
#2
Siriwan Nantaphol, Takeshi Watanabe, Naohiro Nomura, Weena Siangproh, Orawon Chailapakul, Yasuaki Einaga
The enormous demand for medical diagnostics has encouraged the fabrication of high- performance sensing platforms for the detection of glucose. Nonenzymatic glucose sensors are coming ever closer to being used in practical applications. Bimetallic catalysts have been shown to be superior to single metal catalysts in that they have greater activity and selectivity. Here, we demonstrate the preparation, characterization, and electrocatalytic characteristics of a new bimetallic Pt/Au nanocatalyst. This nanocatalyst can easily be synthesized by electrodeposition by sequentially depositing Au and Pt on the surface of a boron-doped diamond (BDD) electrode...
June 17, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28654882/synthesis-and-characterisation-of-robust-emulsion-templated-silica-microcapsules
#3
Shane P Meaney, Rico F Tabor, Bart Follink
Robust silica microcapsules were synthesised using an emulsion template via a seeded growth strategy. Multiple additions of the silica precursor tetraethyl orthosilicate (TEOS) were observed to result in a number of physical and property changes of the capsule shells as compared to a single coating. Scanning electron microscopy indicated a morphological transition from a smooth to a roughened surface. Improved cargo retention and consolidation of the pore structure of the silica shells were observed using dye release experiments and nitrogen porosimetry respectively...
June 8, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28654862/biopolymer-zein-coated-gold-nanoparticles-synthesis-antibacterial-potential-toxicity-and-histopathological-effects-against-the-zika-virus-vector-aedes-aegypti
#4
Periyakaruppan Suganya, Baskaralingam Vaseeharan, Sekar Vijayakumar, Banumathi Balan, Marimuthu Govindarajan, Naiyf S Alharbi, Shine Kadaikunnan, Jamal M Khaled, Giovanni Benelli
The control of multidrug-resistant bacteria as well as insect pests and vectors is timely and important now a days. The present study was designed to evaluate the in vitro antibacterial, antibiofilm and mosquito larvicidal effects of gold nanoparticles synthesized using the zein biopolymer (Ze-AuNPs) against Gram positive (Bacillus pumilus and Bacillus subtilis), Gram negative (Shigella sonnei and Pseudomonas aeruginosa) bacteria and third instar larvae of the dengue and Zika virus vector Aedes aegypti. The synthesized Ze-AuNPs were characterized by UV-vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM)...
June 17, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/28654829/fructose-intake-exacerbates-the-contractile-response-elicited-by-norepinephrine-in-mesenteric-vascular-bed-of-rats-via-increased-endothelial-prostanoids
#5
Glauciene J Sousa, Phablo Wendell C Oliveira, Breno V Nogueira, Antônio F Melo, Thaís de Oliveira Faria, Eduardo Frizera Meira, José G Mill, Nazaré S Bissoli, Marcelo P Baldo
Chronic fructose intake induces major cardiovascular and metabolic disturbances and is associated with the development of hypertension due to changes in vascular function. We hypothesized that high fructose intake for 6 weeks would cause metabolic syndrome and lead to initial vascular dysfunction. Male Wistar rats were assigned to receive fructose (FRU, 10%) or drinking water (CON) for 6 weeks. Systolic blood pressure was evaluated by tail plethysmography. Fasting glucose, insulin and glucose tolerance were measured at the end of the follow-up...
June 20, 2017: Journal of Nutritional Biochemistry
https://www.readbyqxmd.com/read/28654827/characterisation-of-the-medipix3-detector-for-60-and-80kev-electrons
#6
J A Mir, R Clough, R MacInnes, C Gough, R Plackett, I Shipsey, H Sawada, I MacLaren, R Ballabriga, D Maneuski, V O'Shea, D McGrouther, A I Kirkland
In this paper we report quantitative measurements of the imaging performance for the current generation of hybrid pixel detector, Medipix3, used as a direct electron detector. We have measured the modulation transfer function and detective quantum efficiency at beam energies of 60 and 80keV. In single pixel mode, energy threshold values can be chosen to maximize either the modulation transfer function or the detective quantum efficiency, obtaining values near to, or exceeding those for a theoretical detector with square pixels...
June 20, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/28654789/utilization-of-zn-containing-electric-arc-furnace-dust-for-multi-metal-doped-ferrite-with-enhanced-magnetic-property-from-hazardous-solid-waste-to-green-product
#7
Hui-Gang Wang, Mei Zhang, Min Guo
One-step solid state reaction method was proposed for the first time to realize the transformation of the Zn-containing EAFD from hazardous solid waste to multi-metal doped ferrite with enhanced magnetic property. The effect of Zn-containing EAFD to NiCl2·6H2O mass ratio (RZE/N, g·g(-1)) on the phases transformation was investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Raman spectroscopy. The as-synthesized samples were treated by toxicity characteristic leaching procedure (TCLP)...
June 20, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28654748/preparation-of-poly-styrene-b-poly-acrylic-acid-coupled-carbon-dots-and-their-applications
#8
Moon-Jin Cho, Soo-Young Park
Carbon dots (CDs) are covalently coupled to the polyacrylic acid (PAA) block of polystyrene-b-polyacrylic acid (PS-b-PAA). The produced amphiphilic PS-b-PAA-CD shows excellent solubility and micellar formation in selective solvents. Transmission electron microscopy study shows that the micelle of PS-b-PAA-CD in water (a PAA-selective solvent) has a strawberry-like shape with the CDs as patches on the PAA corona surface although that in toluene (a PS-selective solvent) has a reversed shape with the CDs in the core...
June 27, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28654596/a-microbiological-and-ultrastructural-comparison-of-aseptic-versus-sterile-acellular-dermal-matrix-as-a-reconstructive-material-and-a-scaffold-for-stem-cell-ingrowth
#9
Shaun D Mendenhall, Ryan W Schmucker, Timothy H F Daugherty, Katherine M Kottwitz, Joel D Reichensperger, Janak Koirala, Paul S Cederna, Michael W Neumeister
BACKGROUND: Recent data suggest an increased risk for infection when acellular dermal matrix is used in breast reconstruction. This may be because some acellular dermal matrices are actually not terminally sterilized but are instead "aseptically processed." This study evaluates aseptic and sterile matrices for evidence of bacterial contamination and whether or not terminal sterilization affects matrix collagen architecture and stem cell ingrowth. METHODS: Five separate samples of 14 different matrices were analyzed by fluorescent in situ hybridization using a bacterial DNA probe to detect bacterial DNA on the matrices...
July 2017: Plastic and Reconstructive Surgery
https://www.readbyqxmd.com/read/28654334/antennular-morphology-and-contribution-of-aesthetascs-in-the-detection-of-food-related-compounds-in-the-shrimp-palaemon-adspersus-rathke-1837-decapoda-palaemonidae
#10
Paolo Solari, Giorgia Sollai, Carla Masala, Francesco Loy, Francesco Palmas, Andrea Sabatini, Roberto Crnjar
Shrimp are an essential ecological component of marine ecosystems, and have commercial importance for human consumption and aquaculture. Like other decapod crustaceans, shrimp rely on chemical senses to detect and localize food resources by means of chemosensilla that are located mainly on the cephalothoracic appendages. Using the shrimp Palaemon adspersus, a model organism with omnivorous feeding behavior, we aimed to provide comparative information on the role of aesthetascs, antennular sensilla, and flicking behavior in food detection...
April 2017: Biological Bulletin
https://www.readbyqxmd.com/read/28654283/carrier-localization-in-gan-aln-quantum-dots-as-revealed-by-three-dimensional-multimicroscopy
#11
Lorenzo Mancini, Florian Moyon, David Hernàndez-Maldonado, Ivan Blum, Jonathan Houard, Williams Lefebvre, François Vurpillot, Aparna Das, Eva Monroy, Lorenzo Rigutti
The localization of carrier states in GaN/AlN self-assembled quantum dots (QDs) is studied by correlative multimicroscopy relying on microphotoluminescence, electron tomography, and atom probe tomography (APT). Optically active field emission tip specimens were prepared by focused ion beam from an epitaxial film containing a stack of quantum dot layers and analyzed with different techniques applied subsequently on the same tip. The transition energies of single QDs were calculated in the framework of a 6-bands k...
June 27, 2017: Nano Letters
https://www.readbyqxmd.com/read/28654280/molecular-beam-epitaxy-of-gan-nanowires-on-epitaxial-graphene
#12
Sergio Fernandez-Garrido, Manfred Ramsteiner, Guanhui Gao, Lauren A Galves, Bharat Sharma, Pierre Corfdir, Gabriele Calabrese, Ziani de Souza Schiaber, Carsten Pfüller, Achim Trampert, Joao Marcelo J Lopes, Oliver Brandt, Lutz Geelhaar
We demonstrate an all-epitaxial and scalable growth approach to fabricate single-crystalline GaN nanowires on graphene by plasma-assisted molecular beam epitaxy. As substrate, we explore several types of epitaxial graphene layer structures synthesized on SiC. The different structures differ mainly in their total number of graphene layers. Because graphene is found to be etched under active N exposure, the direct growth of GaN nanowires on graphene is only achieved on multilayer graphene structures. The analysis of the nanowire ensembles prepared on multilayer graphene by Raman spectroscopy and transmission electron microscopy reveals the presence of graphene underneath as well as in between nanowires, as desired for the use of this material as contact layer in nanowire-based devices...
June 27, 2017: Nano Letters
https://www.readbyqxmd.com/read/28654234/single-and-networked-zno-cnt-hybrid-tetrapods-for-selective-room-temperature-high-performance-ammonia-sensors
#13
Fabian Schütt, Vasile Postica, Rainer Adelung, Oleg Lupan
Highly porous hybrid materials with unique high-performance properties have attracted great interest from the scientific community, especially in the field of gas-sensing applications. In this work, tetrapodal-ZnO (ZnO-T) networks were functionalized with carbon nanotubes (CNTs) to form a highly efficient hybrid sensing material (ZnO-T-CNT) for ultrasensitive, selective, and rapid detection of ammonia (NH3) vapor at room temperature. By functionalizing the ZnO-T networks with 2.0 wt % of CNTs by a simple dripping procedure, an increase of 1 order of magnitude in response (from about 37 to 330) was obtained...
June 27, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28654181/photoelectrochemical-h2-generation-from-suboxide-tio2-nanotubes-visible-light-absorption-versus-conductivity
#14
Shiva Mohajernia, Seyedsina Hejazi, Anca Mazare, Nhat Truong Nguyen, Patrik Schmuki
In the present work we report on the key factors dictating the photo-electrochemical (PEC) performance of suboxide titania (TiOx) nanotubes. TiOx nanotubes were produced by a systematic variation of reduction heat treatments of TiO2 in Ar/H2. The properties of the TiOx tubes were investigated by electron paramagnetic resonance (EPR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), solid-state conductivity, reflectivity measurements, photocurrent spectroscopy, and photoelectrochemical hydrogen evolution...
June 27, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28654127/bio-camouflage-of-anatase-nanoparticles-explored-by-in-situ-high-resolution-electron-microscopy
#15
Ana R Ribeiro, Arijita Mukherjee, Xuan Hu, Shayan Shafien, Reza Ghodsi, Kun He, Sara Gemini-Piperni, Canhui Wang, Robert F Klie, Tolou Shokuhfar, Reza Shahbazian-Yassar, Radovan Borojevic, Luis A Rocha, José M Granjeiro
While titanium is the metal of choice for most prosthetics and inner body devices due to its superior biocompatibility, the discovery of Ti-containing species in the adjacent tissue as a result of wear and corrosion has been associated with autoimmune diseases and premature implant failures. Here, we utilize the in situ liquid cell transmission electron microscopy (TEM) in a liquid flow holder and graphene liquid cells (GLCs) to investigate, for the first time, the in situ nano-bio interactions between titanium dioxide nanoparticles and biological medium...
June 27, 2017: Nanoscale
https://www.readbyqxmd.com/read/28654068/fabrication-of-3d-carbon-microelectromechanical-systems-c-mems
#16
Bidhan Pramanick, Sergio O Martinez-Chapa, Marc Madou, Hyundoo Hwang
A wide range of carbon sources are available in nature, with a variety of micro-/nanostructure configurations. Here, a novel technique to fabricate long and hollow glassy carbon microfibers derived from human hairs is introduced. The long and hollow carbon structures were made by the pyrolysis of human hair at 900 °C in a N2 atmosphere. The morphology and chemical composition of natural and pyrolyzed human hairs were investigated using scanning electron microscopy (SEM) and electron-dispersive X-ray spectroscopy (EDX), respectively, to estimate the physical and chemical changes due to pyrolysis...
June 17, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28654057/murine-aortic-crush-injury-an-efficient-in-vivo-model-of-smooth-muscle-cell-proliferation-and-endothelial-function
#17
Dan Yu, George Makkar, Rajabrata Sarkar, Dudley K Strickland, Thomas S Monahan
Arterial reconstruction, whether angioplasty or bypass surgery, involves iatrogenic trauma causing endothelial disruption and vascular smooth muscle cell (VSMC) proliferation. Common murine models study small vessels such as the carotid and femoral arteries. Herein we describe an in vivo system in which both VSMC proliferation and endothelial barrier function can be simultaneously assessed in a large vessel. We studied the infrarenal aortic response to injury in C57BL/6 mice. The aorta was injured from the left renal vein to the aortic bifurcation by 30 transmural crushes of 5-seconds duration with a cotton-tipped applicator...
June 11, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28653905/structure-and-in-situ-organisation-of-the-pyrococcus-furiosus-archaellum-machinery
#18
Bertram Daum, Janet Vonck, Annett Bellack, Paushali Chaudhury, Robert Reichelt, Sonja V Albers, Reinhard Rachel, Werner Kühlbrandt
The archaellum is the macromolecular machinery that archaea use for propulsion or surface adhesion, enabling them to proliferate and invade new territories. The molecular composition of the archaellum and of the motor that drives it appears to be entirely distinct from that of the functionally equivalent bacterial flagellum and flagellar motor. Yet, the structure of the archaellum machinery is scarcely known. Using combined modes of electron cryo-microscopy (cryoEM), we have solved the structure of the Pyrococcus furiosus archaellum filament at 4...
June 27, 2017: ELife
https://www.readbyqxmd.com/read/28653860/gadolinium-deposition-in-human-brain-tissues-after-contrast-enhanced-mr-imaging-in-adult-patients-without-intracranial-abnormalities
#19
Robert J McDonald, Jennifer S McDonald, David F Kallmes, Mark E Jentoft, Michael A Paolini, David L Murray, Eric E Williamson, Laurence J Eckel
Purpose To determine whether gadolinium deposits in neural tissues of patients with intracranial abnormalities following intravenous gadolinium-based contrast agent (GBCA) exposure might be related to blood-brain barrier integrity by studying adult patients with normal brain pathologic characteristics. Materials and Methods After obtaining antemortem consent and institutional review board approval, the authors compared postmortem neuronal tissue samples from five patients who had undergone four to 18 gadolinium-enhanced magnetic resonance (MR) examinations between 2005 and 2014 (contrast group) with samples from 10 gadolinium-naive patients who had undergone at least one MR examination during their lifetime (control group)...
June 27, 2017: Radiology
https://www.readbyqxmd.com/read/28653843/scalable-and-low-cost-synthesis-of-highly-conducting-polypyrrole-nanofibers-using-oil-water-interfacial-polymerization-under-constant-stirring
#20
Jayanta Hazarika, Ashok Kumar
In the present work, we report a low cost and scalable oil-water interfacial polymerization method to synthesize one dimensional (1-D) highly conducting polypyrrole (PPy) nanofibers doped with p-Toluenesulfonic (p-TSA) and hydrochloric (HCl) acids. Polymerization of pyrrole (monomer) has been carried out at the interface formed between the immiscible oil and aqueous water droplets under constant magnetic stirring at room temperature. Formation of smaller diameter (16-20 nm) PPy nanofibers has been confirmed from the high resolution transmission electron microscopy (HRTEM) studies and average diameter of p-TSA doped PPy nanofibers is found to be smaller than that of HCl doped nanofibers...
June 27, 2017: Journal of Physical Chemistry. B
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