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https://www.readbyqxmd.com/read/28540865/directed-growth-of-graphene-nanomesh-in-purified-argon-via-chemical-vapor-deposition
#1
Haibin Sun, Can Fu, Xia Shen, Wenchao Yang, Pengfei Guo, Yang Lu, Yongsong Luo, Benhai Yu, Xiaoge Wang, Chunlei Wang, Junqi Xu, Jiangfeng Liu, Fengqi Song, Guanghou Wang, Jianguo Wan
Graphene nanomeshes (GNMs), new graphene nanostructures with tunable bandgaps, are potential building blocks for future electronic or photonic devices, and energy storage and conversion materials. In previous works, GNMs have been successfully prepared on Cu foils by the H2 etching effect. In this paper, we investigated the effect of Ar on the preparation of GNMs, and how the mean density and shape of them vary with growth time. In addition, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (TEM) revealed the typical hexagonal structure of GNM...
June 16, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28539033/the-usefulness-of-argon-plasma-coagulation-compared-with-endoscopic-submucosal-dissection-to-treat-gastric-adenoma
#2
Dong Hyun Lee, Won Ki Bae, Jong Wook Kim, Woo Hyun Paik, Nam Hoon Kim, Kyung Ah Kim, June Sung Lee
Background/Aims: To date, the best therapeutic modality for gastric adenoma, especially low-grade adenoma, has not been established. The aim of this study was to assess the usefulness of argon plasma coagulation (APC) in treating gastric adenoma compared with endoscopic submucosal dissection (ESD). Methods: We included 210 patients with gastric adenoma, who underwent treatment with either APC (97 patients) or ESD (113 patients). The clinical and pathologic characteristics, mean duration of hospital stay, complications, and recurrence rates between the two groups were compared...
May 25, 2017: Korean Journal of Gastroenterology, Taehan Sohwagi Hakhoe Chi
https://www.readbyqxmd.com/read/28535686/development-and-characterization-of-a-stable-adhesive-bond-between-a-poly-dimethylsiloxane-catheter-material-and-a-bacterial-biofilm-resistant-acrylate-polymer-coating
#3
Bonnie J Tyler, Andrew Hook, Andreas Pelster, Paul Williams, Morgan Alexander, Heinrich F Arlinghaus
Catheter associated urinary tract infections are the most common health related infections worldwide, contributing significantly to patient morbidity and mortality and increased health care costs. To reduce the incidence of these infections, new materials that resist bacterial biofilm formation are needed. A composite catheter material, consisting of bulk poly(dimethylsiloxane) (PDMS) coated with a novel bacterial biofilm resistant polyacrylate [ethylene glycol dicyclopentenyl ether acrylate (EGDPEA)-co-di(ethyleneglycol) methyl ether methacrylate (DEGMA)], has been proposed...
May 23, 2017: Biointerphases
https://www.readbyqxmd.com/read/28535660/-clinical-investigation-on-ct-guided-cryoablation-for-treating-invasive-chest-wall-or-pleural-tumors
#4
M Wang, Y W Pan, Z G Zhou, Y Cui, K P Du, S Li
Objective: To evaluate the feasibility and short-term effect of CT guided cryoablation for malignant chest wall or pleural involvement. Methods: To follow up 22 patients with chest wall or pleural involvement of various malignancies who underwent cryoablation from January 2012 to January 2015 by conducting postoperative 1-, 3- and 6-month enhanced CT, MRI or PET-CT examinations, respectively, evaluate local curative effect, and observe their progression-free survival (PFS), postoperative pain remission and complications after the cryoablation...
May 23, 2017: Zhonghua Zhong Liu za Zhi [Chinese Journal of Oncology]
https://www.readbyqxmd.com/read/28532748/transfemoral-filter-eversion-technique-following-unsuccessful-retrieval-of-option-inferior-vena-cava-filters-a-single-center-experience
#5
Raghuram Posham, Aaron M Fischman, Francis S Nowakowski, Vivian L Bishay, Derek M Biederman, Jaskirat S Virk, Edward Kim, Rahul S Patel, Robert A Lookstein
This report describes the technical feasibility of using the filter eversion technique after unsuccessful retrieval attempts of Option and Option ELITE (Argon Medical Devices, Inc, Athens, Texas) inferior vena cava (IVC) filters. This technique entails the use of endoscopic forceps to evert this specific brand of IVC filter into a sheath inserted into the common femoral vein, in the opposite direction in which the filter is designed to be removed. Filter eversion was attempted in 25 cases with a median dwell time of 134 days (range, 44-2,124 d)...
June 2017: Journal of Vascular and Interventional Radiology: JVIR
https://www.readbyqxmd.com/read/28530605/screening-of-passiflora-l-mineral-content-using-principal-component-analysis-and-kohonen-self-organizing-maps
#6
Cleber Galvão Novaes, Ivana Lago da Silva Romão, Berlane Gomes Santos, Jéssica Palhares Ribeiro, Marcos Almeida Bezerra, Erik Galvão Paranhos da Silva
A method using digestion with diluted nitric acid and inductively coupled plasma optical emission spectrometry was applied to determine metal ions in the peel, pulp, and seed of Passiflora edulis f. flavicarpa and Passiflora cincinnata cultivated in the Bahia state, Brazil. Plasma parameters (radio frequency power and argon flow rates) were optimized. The quantification limits (µg g(-1)) were: Ca (43.0); Co (1.3); Cu (10.0); Fe (10.0); K (20.0); Mg (26.6); Mn (0.33); Na (56.6) and Zn (10.0). The accuracy of the method was evaluated by the analysis of certified reference materials (NIST 1567a Wheat Flour and NIST 1577b Bovine Liver)...
October 15, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28527185/surface-heparinization-and-blood-compatibility-modification-of-small-intestinal-submucosa-sis-for-small-caliber-vascular-regeneration
#7
Bensong Han, Feng Xue, Cunyi Fan, Xiumei Mo
OBJECTIVES: This study aims to investigate the small intestinal submucosal (SIS) surface after heparinization with the hypothermia plasma technique, to improve the blood compatibility of SIS, and to explore the possibility of construction of small-caliber vascular grafts with modified SIS scaffolds in vivo. METHODS: SIS films prepared from jejunums of pigs were processed for surface treatment at different time periods with the argon plasma initiation technique under vacuum, and were then immediately immersed in 4% (m/v) heparin sodium solution for 24-h heparinization...
2017: Bio-medical Materials and Engineering
https://www.readbyqxmd.com/read/28524808/determination-of-safe-and-critical-nanoparticles-exposure-to-welders-in-a-workshop
#8
J F Gomes, R M Miranda
The present study examined consequences of "safe" versus "critical" exposure to nanoparticles (NP) released during welding operations. With this aim in mind, a set of measurements regarding NP emissions was undertaken in a workshop during welding by metal active gas of carbon steel using different mixtures of argon (Ar) and carbon dioxide (CO2) as well as different process parameters which might influence emission of (NP). If these measurements were conducted in several locations away from the welding sources, the graphical representation of the obtained observations with time enabled definition of "safe" and "critical" regions within a welding workshop in terms of welder's exposure...
May 19, 2017: Journal of Toxicology and Environmental Health. Part A
https://www.readbyqxmd.com/read/28522242/monitoring-the-surface-quality-of-silver-plasmon-waveguides-with-nonlinear-photoemission-electron-microscopy-and-in-situ-ion-sputtering
#9
Kellie Pearce, Francis Schuknecht, Christian Späth, Benjamin Duschner, Florian Richter, Ulf Kleineberg
We use photoemission electron microscopy (PEEM) with single- and two-photon excitation to study the properties of surface plasmon polaritons (SPPs) in tapered silver stripe waveguides. Arrays of waveguides with different widths, grating coupler geometries, and taper angles are fabricated using electron beam lithography (EBL) on Si and indium-tin-oxide (ITO)-covered glass substrates. The presence of propagating SPP modes is indicated by modulations of the non-linear photoemission intensity which run along the length of the waveguide - the result of interfering SPPs reflected from the edges...
May 10, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/28521497/thermal-decomposition-of-nitromethane-and-reaction-between-ch3-and-no2
#10
Akira Matsugi, Hiroumi Shiina
The thermal decomposition of gaseous nitromethane and the subsequent bimolecular reaction between CH3 and NO2 have been experimentally studied using time-resolved cavity-enhanced absorption spectroscopy behind reflected shock waves in the temperature range 1336-1827 K and at a pressure of 100 kPa. Temporal evolution of NO2 was observed following the pyrolysis of nitromethane (diluted to 80-140 ppm in argon) by monitoring the absorption around 400 nm. The primary objectives of the current work were to evaluate the rate constant for the CH3 + NO2 reaction (k2) and to examine the contribution of the roaming isomerization pathway in nitromethane decomposition...
May 26, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28512304/nearly-perfect-durable-superhydrophobic-surfaces-fabricated-by-a-simple-one-step-plasma-treatment
#11
Jeongeun Ryu, Kiwoong Kim, JooYoung Park, Bae Geun Hwang, YoungChul Ko, HyunJoo Kim, JeongSu Han, EungRyeol Seo, YongJong Park, Sang Joon Lee
Fabrication of superhydrophobic surfaces is an area of great interest because it can be applicable to various engineering fields. A simple, safe and inexpensive fabrication process is required to fabricate applicable superhydrophobic surfaces. In this study, we developed a facile fabrication method of nearly perfect superhydrophobic surfaces through plasma treatment with argon and oxygen gases. A polytetrafluoroethylene (PTFE) sheet was selected as a substrate material. We optimized the fabrication parameters to produce superhydrophobic surfaces of superior performance using the Taguchi method...
May 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28510284/tricyanomethane-and-its-ketenimine-tautomer-generated-from-different-precursors-and-analyzed-in-solution-argon-matrix-and-single-crystal
#12
Klaus Banert, Madhu Chityala, Manfred Hagedorn, Helmut Beckers, Tony Stüker, Sebastian Riedel, Tobias Rüffer, Heinrich Lang
Solutions of azidomethylidenemalononitrile were photolyzed at low temperatures to produce the corresponding 2H-azirine and tricyanomethane, which were analyzed by low-temperature NMR spectroscopy. The latter product was also observed after short thermolysis of the azide precursor in solution, whereas irradiation of the azide isolated in an argon matrix did not lead to tricyanomethane, but to unequivocal detection of the tautomeric ketenimine by IR spectroscopy for the first time. When the long-known "aquoethereal" greenish phase, generated from potassium tricyanomethanide, dilute sulfuric acid, and diethyl ether, was rapidly evaporated and sublimed, a mixture of hydronium tricyanomethanide and tricyanomethane was formed instead of previously claimed ketenimine tautomer...
May 16, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28506588/double-balloon-enteroscopy-indications-approaches-diagnostic-and-therapeutic-efficacy-and-safety-early-experience-at-a-single-center
#13
J J E García-Correa, J J Ramírez-García, L F García-Contreras, C Fuentes-Orozco, L Irusteta-Jiménez, L R Michel-Espinoza, A S Carballo Uribe, J A Torres Chávez, A González-Ojeda
INTRODUCTION AND AIMS: Double-balloon enteroscopy has been improving the visualization of the entire intestine for more than a decade. It is a complementary method in the study of intestinal diseases that enables biopsies to be taken and treatments to be administered. Our aim was to describe its main indications, insertion routes, diagnostic/therapeutic efficacy, and complications. MATERIALS AND METHODS: All patients referred to our unit with suspected small bowel pathology were included...
May 12, 2017: Revista de Gastroenterología de México
https://www.readbyqxmd.com/read/28505763/comparative-study-of-noise-in-low-current-townsend-discharge-in-nitrogen-and-argon
#14
Yu A Astrov, A N Lodygin, L M Portsel, E V Beregulin
Noise in a low-current Townsend discharge in argon and nitrogen is studied. Experiments were performed in a "semiconductor-gas-discharge" structure constituted by a short plane-parallel discharge gap and a high-resistivity photosensitive semiconductor electrode. The noise of optical emission from gas excited by the discharge was investigated with a photomultiplier. Experiments were done at the room temperature of the discharge structure. According to the obtained data, the noise of discharge glow in Ar is astonishingly low-similar to that earlier found for the cryogenic discharge in this gas...
April 2017: Physical Review. E
https://www.readbyqxmd.com/read/28493428/optical-thermal-and-mechanical-characterization-of-ga2-se3-added-gls-glass
#15
Andrea Ravagli, Christopher Craig, Ghada A Alzaidy, Paul Bastock, Daniel W Hewak
Gallium lanthanum sulfide glass (GLS) has been widely studied in the last 40 years for middle-infrared applications. In this work, the results of the substitution of selenium for sulphur in GLS glass are described. The samples are prepared via melt-quench method in an argon-purged atmosphere. A wide range of compositional substitutions are studied to define the glass-forming region of the modified material. The complete substitution of Ga2 S3 by Ga2 Se3 is achieved by involving new higher quenching rate techniques compared to those containing only sulfides...
May 11, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28487005/nitrogen-gas-field-ion-source-gfis-focused-ion-beam-fib-secondary-electron-imaging-a-first-look
#16
Marek E Schmidt, Anto Yasaka, Masashi Akabori, Hiroshi Mizuta
The recent technological advance of the gas field ion source (GFIS) and its successful integration into systems has renewed the interest in the focused ion beam (FIB) technology. Due to the atomically small source size and the use of light ions, the limitations of the liquid metal ion source are solved as device dimensions are pushed further towards the single-digit nanometer size. Helium and neon ions are the most widely used, but a large portfolio of available ion species is desirable, to allow a wide range of applications...
May 10, 2017: Microscopy and Microanalysis
https://www.readbyqxmd.com/read/28485607/periodic-dispersion-corrected-approach-for-isolation-spectroscopy-of-n2-in-an-argon-environment-clusters-surfaces-and-matrices
#17
Y Makina, K Mahjoubi, D M Benoit, N-E Jaidane, M Mogren Al-Mogren, M Hochlaf
Ab initio and Perdew, Burke, and Ernzerhof (PBE) density functional theory with dispersion correction (PBE-D3) calculations are performed to study N2-Arn (n ≤ 3) complexes and N2 trapped in Ar matrix (i.e., N2@Ar). For cluster computations, we used both Møller-Plesset (MP2) and PBE-D3 methods. For N2@Ar, we used a periodic-dispersion corrected model for Ar matrix, which consists on a slab of four layers of Ar atoms. We determined the equilibrium structures and binding energies of N2 interacting with these entities...
May 18, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28485570/tuning-porosity-and-surface-area-in-mesoporous-silicon-for-application-in-li-ion-battery-electrodes
#18
John B Cook, Hyung-Seok Kim, Terri Chai Lin, Shauna Robbennolt, Eric Detsi, Bruce S Dunn, Sarah H Tolbert
This work aims to improve the poor cycle lifetime of silicon based anodes for Li-ion batteries by tuning microstructural parameters such as pore size, pore volume, and specific surface area in chemically synthesized mesoporous silicon. Here we have specifically produced two different mesoporous silicon samples from the magnesiothermic reduction of ordered mesoporous silica in either argon or forming gas. In-situ X-ray diffraction studies indicate that samples made in Ar proceed through a Mg2Si intermediate, and this results in samples with larger pores (diameter ~90 nm), modest total porosity (34%), and modest specific surface area (50 m2 g-1)...
May 9, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28482531/zn-li-alloy-after-extrusion-and-drawing-structural-mechanical-characterization-and-biodegradation-in-abdominal-aorta-of-rat
#19
Shan Zhao, Jan-M Seitz, Rainer Eifler, Hans J Maier, Roger J Guillory, Elisha J Earley, Adam Drelich, Jeremy Goldman, Jaroslaw W Drelich
Zinc shows great promise as a bio-degradable metal. Our early in vivo investigations implanting pure zinc wires into the abdominal aorta of Sprague-Dawley rats revealed that metallic zinc does not promote restenotic responses and may suppress the activities of inflammatory and smooth muscle cells. However, the low tensile strength of zinc remains a major concern. A cast billet of the Zn-Li alloy was produced in a vacuum induction caster under argon atmosphere, followed by a wire drawing process. Two phases of the binary alloy identified by x-ray diffraction include the zinc phase and intermetallic LiZn4 phase...
July 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28481530/aliphatic-c-h-bond-iodination-by-a-n-iodoamide-and-isolation-of-elusive-n-amidyl-radical
#20
Alexander Artaryan, Artur Mardyukov, Kseniya Kulbitski, Idan Avigdori, Gennady A Nisnevich, Peter R Schreiner, Mark Gandelman
Contrary to C-H chlorination and bromination, the direct iodination of alkanes represents a great challenge. We reveal a new N-iodoamide which capable of a direct and efficient C-H bond iodination of various cyclic and acyclic alkanes providing iodoalkanes in good yields. This is the first use of N-iodoamide for C-H bond iodination. The method also works well for benzylic C-H bonds, thereby constituting the missing version of Wohl-Ziegler iodination reaction. Mechanistic details were elucidated by DFT computations, and the N-centered radical derived from the used N-iodoamide, which is the key intermediate in this process, was matrix-isolated in solid argon matrix and characterized by UV-Vis as well as IR spectroscopy...
May 8, 2017: Journal of Organic Chemistry
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