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https://www.readbyqxmd.com/read/28535591/effect-of-water-stage-and-tree-stand-composition-on-spatiotemporal-differentiation-of-spring-water-chemistry-draining-carpathian-flysch-slopes-gorce-mts
#1
Michał Jasik, Stanisław Małek, Mirosław Żelazny
The purpose of this study was to identify the factors affecting spring water chemistry in different tree stands and to measure the influence of water stage on the physicochemical parameters of spring waters in a small Carpathian catchment. Water samples were collected three times per year at various stages of the water: after the spring thaw, after a period of heavy rain and after a dry period in 2011 and 2012. Water samples were left in the laboratory to reach room temperature (19-20°C) and analyzed for EC (reference T=25°C) and pH...
May 19, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28534055/experimental-determination-of-surface-heat-transfer-coefficient-in-a-dry-ice-ethanol-cooling-bath-using-a-numerical-approach
#2
M V Santos, M Sansinena, N Zaritzky, J Chirife
  BACKGROUND: Dry ice-ethanol bath (-78 degree C) have been widely used in low temperature biological research to attain rapid cooling of samples below freezing temperature. The prediction of cooling rates of biological samples immersed in dry ice-ethanol bath is of practical interest in cryopreservation. The cooling rate can be obtained using mathematical models representing the heat conduction equation in transient state. Additionally, at the solid cryogenic-fluid interface, the knowledge of the surface heat transfer coefficient (h) is necessary for the convective boundary condition in order to correctly establish the mathematical problem...
March 2017: Cryo Letters
https://www.readbyqxmd.com/read/28525273/directional-fluid-gating-by-janus-membranes-with-heterogeneous-wetting-properties-for-selective-oil-water-separation
#3
Prashant Gupta, Balasubramanian Kandasubramanian
The rising oil seepage accidents evolved into a global issue necessitating immediate counter measure to abridge its catastrophic repercussions on sensitive marine ecosystem urging innovative techniques for effective oil/water separation. Here, we report surface tailored wettability modified superhydrophobic/superoleophilic Janus membrane by impregnating non-ionic surfactant stabilized nano-sized polytetrafluoroethylene (PTFE) dispersion polymerized via non-fluorinated processing aid onto cotton substrate using Meyer rod coating technique, exhibiting excellent separation efficiency up to 98% with various petroleum products and retaining its intrinsic properties for at least 30 recurrences...
May 19, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28523174/rupture-of-gore-tex-neochordae-10-years-after-mitral-valve-repair
#4
Makoto Mori, Philip Y K Pang, Sabet W Hashim
The current non-resectional paradigm in mitral valve (MV) repair emphasizes the use of polytetrafluoroethylene (PTFE) for artificial chordal replacement. While excellent long-term durability of repair using PTFE neochordae has been established, there have been rare reports of neochordal rupture at various times after surgery. We report a case of artificial chordal rupture 10 years after anterior mitral leaflet repair, necessitating reoperation. This complication may have been precipitated by maldistributed intracardiac tensile forces as a consequence of a malpositioned annuloplasty band...
April 2017: Journal of Thoracic Disease
https://www.readbyqxmd.com/read/28521218/the-effect-of-temperature-on-contact-angles-and-wetting-transitions-for-n-alkanes-on-ptfe
#5
M Elena Diaz, Michael D Savage, Ramon L Cerro
The aim of this paper is to present a method for predicting the effect of temperature on contact angles and wetting transitions for n-alkanes on PTFE. The analysis is based on the effect of temperature on two closely related phenomena, which are critical in the determination of contact angles: intermolecular forces and the thickness of an adsorbed film in the region adjacent to the three-phase contact. Considering solely van der Waals forces, it is possible to reproduce the experimental temperature dependence of contact angles...
May 4, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28515572/a-family-of-fe-n-c-oxygen-reduction-electrocatalysts-for-microbial-fuel-cell-mfc-application-relationships-between-surface-chemistry-and-performances
#6
Carlo Santoro, Alexey Serov, Rohan Gokhale, Santiago Rojas-Carbonell, Lydia Stariha, Jonathan Gordon, Kateryna Artyushkova, Plamen Atanassov
Different iron-based cathode catalysts have been studied for oxygen reduction reaction (ORR) in neutral media and then applied into microbial fuel cells (MFC). The catalysts have been synthesized using sacrificial support method (SSM) using eight different organic precursors named Niclosamide, Ricobendazole, Guanosine, Succinylsulfathiazole, Sulfacetamide, Quinine, Sulfadiazine and Pyrazinamide. Linear Sweep Voltammetry (LSV) curves were obtained for the catalysts using a O2 saturated in 0.1 M potassium phosphate buffer and 0...
May 15, 2017: Applied Catalysis. B, Environmental
https://www.readbyqxmd.com/read/28512687/added-value-of-covered-stents-in-transjugular-intrahepatic-portosystemic-shunt-a-large-single-center-experience
#7
Amar C Gupta, Weiping Wang, Chintan Shah, Mark J Sands, Jennifer Bullen, Erick M Remer, Pilar M Bayona, William Carey, Baljendra Kapoor
PURPOSE: Transjugular intrahepatic portosystemic shunts (TIPS) were historically placed using uncovered bare-metal stents. Current practice has now shifted toward the use of polytetrafluoroethylene (PTFE)-covered stents, given the improved primary patency seen with these stents. The aim of this study was to determine whether there is any added value, such as overall survival or stent patency, when using covered stents versus uncovered stents in TIPS placement in a large cohort. MATERIALS AND METHODS: From April 1995 to June 2012, a total of 744 consecutive adult patients underwent de novo TIPS placement (378 receiving uncovered stents, 366 receiving covered stents)...
May 16, 2017: Cardiovascular and Interventional Radiology
https://www.readbyqxmd.com/read/28512304/nearly-perfect-durable-superhydrophobic-surfaces-fabricated-by-a-simple-one-step-plasma-treatment
#8
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/28506101/evaluation-of-personal-inhalable-aerosol-samplers-with-different-filters-for-use-during-anthrax-responses
#9
Sergey A Grinshpun, Angela M Weber, Michael Yermakov, Reshmi Indugula, Yousef Elmashae, Tiina Reponen, Laura Rose
Risk of inhalation exposure to viable Bacillus anthracis (B. anthracis) spores has primarily been assessed using short-term, stationary sampling methods which may not accurately characterize the concentration of inhalable-sized spores reaching a person's breathing zone. While a variety of aerosol sampling methods have been utilized during previous anthrax responses, no consensus has yet been established for personal air sampling. The goal of this study was to determine the best sampler-filter combination(s) for the collection and extraction of B...
May 16, 2017: Journal of Occupational and Environmental Hygiene
https://www.readbyqxmd.com/read/28503009/performance-of-metal-and-polymeric-o-ring-seals-during-beyond-design-basis-thermal-conditions
#10
Jiann C Yang, Edward Hnetkovsky, Doris Rinehart, Marco Fernandez, Felix Gonzalez, Joseph Borowsky
This paper summarizes the small scale thermal exposure test results of the performance of metallic and polymeric O-ring seals typically used in radioactive material transportation packages. Five different O-ring materials were evaluated: Inconel/silver, ethylene-propylene diene monomer (EPDM), polytetrafluoroethylene (PTFE), silicone, butyl, and Viton. The overall objective of this study is to provide test data and insights to the performance of these Oring seals when exposed to beyond-design-basis temperature conditions due to a severe fire...
April 2017: Polymer Testing
https://www.readbyqxmd.com/read/28502428/non-proximate-mass-spectrometry-using-a-heated-1-m-long-ptfe-tube-and-an-air-tight-apci-ion-source
#11
Dilshadbek T Usmanov, Kenzo Hiraoka, Hiroshi Wada, Masaya Matsumura, Sachiyo Sanada-Morimura, Hiroshi Nonami, Shinichi Yamabe
Direct and rapid trace-level gas analysis is highly needed in various fields such as safety and security, quality control, food analysis, and forensic medicine. In many cases, the real samples are bulky and are not accessible to the space-limited ion source of the mass spectrometer. In order to circumvent this problem, we developed an airtight atmospheric-pressure chemical ionization (APCI) ion source equipped with a flexible 1-m-long, 2-mm-i.d. PTFE sniffing tube. The ambient air bearing sample gas was sucked into the heated PTFE tube (130 °C) and was transported to the air-tight ion source without using any extra pumping system or a Venturi device...
June 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28487112/outcomes-of-self-expanding-ptfe-covered-stent-versus-bare-metal-stent-for-chronic-iliac-artery-occlusion-in-matched-cohorts-using-propensity-score-modelling
#12
M Piazza, F Squizzato, A Dall'Antonia, S Lepidi, M Menegolo, F Grego, M Antonello
OBJECTIVES: The aim was to compare outcomes of self expanding PTFE covered stents (CSs) with bare metal stents (BMSs) in the treatment of iliac artery occlusions (IAOs). METHODS: Between January 2009 and December 2015, 128 iliac arteries were stented for IAO. A CS was implanted in 78 iliac arteries (61%) and a BMS in 50 (49%). After propensity score matching, 94 limbs were selected and underwent stenting (47 for each group). Thirty day outcomes and midterm patency were compared; follow-up results were analysed with Kaplan-Meier curves...
May 6, 2017: European Journal of Vascular and Endovascular Surgery
https://www.readbyqxmd.com/read/28479468/a-ten-year-experience-using-a-hybrid-endovascular-approach-to-treat-aberrant-subclavian-arterial-aneurysms
#13
Mathew Wooster, Martin Back, Danielle Sutzko, Hollie Gaeto, Paul Armstrong, Murray Shames
BACKGROUND: To describe a single center experience using combined extra-anatomic open arch branch revascularization with aortic arch endovascular exclusion for treatment of aberrant subclavian artery aneurysms. METHODS: All patients undergoing management of aberrant subclavian aneurysms were identified from a prospective patient registry. Means of revascularization included carotid-subclavian bypass or subclavian transposition and origin occlusion was performed by surgical ligation or endovascular embolization at surgeon discretion...
May 4, 2017: Annals of Vascular Surgery
https://www.readbyqxmd.com/read/28479462/iliac-artery-stenting-combined-with-ipsilateral-open-femoro-popliteal-revascularization-and-its-effect-on-bypass-patency
#14
Michele Piazza, Francesco Squizzato, Sandro Lepidi, Mirko Menegolo, Franco Grego, Michele Antonello
OBJECTIVES: In cases of multilevel obstructive atherosclerotic disease, hybrid procedures of concomitant iliac artery stenting and femoro-popliteal bypass (IS-FPB) may represent a valid approach, but results are still unclear. The aim was to evaluate early and long-term outcomes of concurrent IS-FPB. METHODS: This retrospective study included 75 patients (76 limbs) treated with concomitant IS-FPB between January 2010 and June 2016. All patients were prospectively enrolled in a dedicated database...
May 4, 2017: Annals of Vascular Surgery
https://www.readbyqxmd.com/read/28479424/open-and-endovascular-management-of-inferior-mesenteric-artery-aneurysms-a-report-of-two-cases
#15
Natasha Hansraj, Abdulrahman Hamdi, Eric S Wise, Laura DiChiacchio, Rajabrata Sarkar, Shahab Toursavadkohi
Inferior mesenteric artery (IMA) aneurysms are a rare entity, attributing to 1% of sphlanic aneurysms, [1] often found incidentally on evaluation for other intra-abdominal pathologies. Similar to other visceral arterial aneurysm, there is an estimated 20-50% risk of potentially fatal rupture and repair is generally recommended. We report two patients with IMA aneurysms, using them as cases to illustrate feasibility of both open and endovascular management options. Patient one is a 69-year-old male with bilateral claudication found to have an asymptomatic 20 mm IMA aneurysm...
May 4, 2017: Annals of Vascular Surgery
https://www.readbyqxmd.com/read/28478681/sensitive-determination-of-cd-in-small-volume-samples-by-miniaturized-liquid-drop-anode-atmospheric-pressure-glow-discharge-optical-emission-spectrometry
#16
Piotr Jamroz, Krzysztof Greda, Anna Dzimitrowicz, Krzysztof Swiderski, Pawel Pohl
A novel liquid drop anode (LDA) direct current atmospheric pressure glow discharge (dc-APGD) system was applied for direct determination of Cd in small-volume samples solutions by optical emission spectrometry (OES). The microdischarge was generated in open-to-air atmosphere between a solid pin type tungsten cathode and liquid drop placed on a graphite disk anode. The arrangement of the graphite disk placed on a PTFE chip platform as well as the solid pin type cathode was simple and robust. The limit of detection (LOD) of Cd for the developed LDA-APGD-OES method was 0...
May 6, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28470270/biomimetic-synthesis-of-ag3po4-nps-cu-nws-with-visible-light-enhanced-photocatalytic-activity-for-degradation-of-the-antibiotic-ciprofloxacin
#17
Yuling Liu, Qingsheng Wu, Yaping Zhao
1D Ag3PO4-NPs/Cu-NWs have been constructed to enhance visible-light-driven photocatalytic activity via biomimetic synthesis. Cu nanowires (NWs) were synthesized by a facile hydrothermal method. During the process of biomimetic synthesis, the porous PTFE film, which can mimic the transport process of cell membranes, plays an important role in controlling the transport speed of silver ions (Ag(+)) to decrease the reaction speed. Thus inhibition of the replacement reaction of Ag(+)/Cu and the uniform growth of Ag3PO4 nanoparticles (NPs) with a diameter of about 10 nm on Cu-NWs can be realized simultaneously...
May 16, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28466979/polytetrafluoroethylene-topographies-determine-the-adhesion-activation-and-foreign-body-giant-cell-formation-of-macrophages
#18
Sujan Lamichhane, Jordan A Anderson, Thomas Vierhout, Tyler Remund, Hongli Sun, Patrick Kelly
Polytetrafluoroethylene (PTFE) is one of the commonly used materials in making various cardiovascular implants. However, the success rates of these implants in several occasions is hindered by unwanted immune responses from immune cells, such as macrophages. In this study, we investigated the response of macrophages with different structures (flat, expanded, and electrospun) of PTFE having varied surface topographies: smooth planar surface (flat PTFE), node-fibrils (ePTFE), and randomly oriented micro fibers (electrospun PTFE)...
May 3, 2017: Journal of Biomedical Materials Research. Part A
https://www.readbyqxmd.com/read/28449480/reconstruction-of-mediastinal-vessels-for-invasive-thymoma-a-retrospective-analysis-of-25-cases
#19
Yifeng Sun, Chang Gu, Jianxin Shi, Wentao Fang, Qingquan Luo, Dingzhong Hu, Shijie Fu, Xufeng Pan, Yong Chen, Yu Yang, Haitang Yang, Heng Zhao, Haiquan Chen
BACKGROUND: Discuss an appropriate strategy for treatment of invasive thymoma invading adjacent great vessels. METHODS: A retrospective study on 25 patients with invasive thymoma invading neighboring great vessels was performed. The corresponding data including clinical presentation, operation procedure, adjuvant radio-chemotherapy and follow-up were reviewed. RESULTS: Twenty of 25 (80%) patients with invasive thymoma underwent complete resection of the tumor along with vessel reconstruction...
March 2017: Journal of Thoracic Disease
https://www.readbyqxmd.com/read/28448003/standardized-method-for-measuring-collection-efficiency-from-wipe-sampling-of-trace-explosives
#20
Jennifer R Verkouteren, Jeffrey A Lawrence, Matthew E Staymates, Edward Sisco
One of the limiting steps to detecting traces of explosives at screening venues is effective collection of the sample. Wipe-sampling is the most common procedure for collecting traces of explosives, and standardized measurements of collection efficiency are needed to evaluate and optimize sampling protocols. The approach described here is designed to provide this measurement infrastructure, and controls most of the factors known to be relevant to wipe-sampling. Three critical factors (the applied force, travel distance, and travel speed) are controlled using an automated device...
April 10, 2017: Journal of Visualized Experiments: JoVE
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