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https://www.readbyqxmd.com/read/28875448/clinical-outcomes-of-af-patients-treated-with-the-first-and-second-generation-of-circular-mapping-and-ablation-catheter-insights-from-a-real-world-multicenter-experience
#1
Giovanni Rovaris, Paolo De Filippo, Francesco Laurenzi, Gabriele Zanotto, Nicola Bottoni, Mattia Pozzi, Fabrizio Giofrè, Piergiuseppe De Girolamo, Emanuela Visentin, Elena Piazzi, Paola Ferrari
PURPOSE: Complete pulmonary vein isolation (PVI) is the best documented target for catheter ablation, and different technologies have shown comparable outcomes. The multielectrode phased-RF/duty cycled (PhRF/DC) pulmonary vein ablation catheter (PVAC) and its second generation (PVAC-GOLD) have shown promising clinical results in single and multicenter experiences. Our aim is to assess and compare the safety and efficacy in the real clinical practice among two generations of circular PhRF/DC catheters by performing PVI in patients suffering from recurrent atrial fibrillation (AF)...
September 5, 2017: Journal of Interventional Cardiac Electrophysiology: An International Journal of Arrhythmias and Pacing
https://www.readbyqxmd.com/read/28867448/moisture-induced-phase-separation-and-recrystallization-in-amorphous-solid-dispersions
#2
Christian Luebbert, Gabriele Sadowski
Active Pharmaceutical Ingredients (APIs) are often dissolved in polymeric matrices to control the gastrointestinal dissolution and to stabilize the amorphous state of the API. During the pharmaceutical development of new formulations, stability studies via storage at certain temperature and relative humidity (RH) have to be carried out to verify the long-term thermodynamic stability of these formulations against unwanted recrystallization and moisture-induced amorphous-amorphous phase separation (MIAPS). This study focuses on predicting the MIAPS of API/polymer formulations at elevated RH...
August 31, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28852703/biomimetic-reversible-heat-stiffening-polymer-nanocomposites
#3
Elvis Cudjoe, Shaghayegh Khani, Amanda E Way, Michael J A Hore, Joao Maia, Stuart J Rowan
Inspired by the ability of the sea cucumber to (reversibly) increase the stiffness of its dermis upon exposure to a stimulus, we herein report a stimuli-responsive nanocomposite that can reversibly increase its stiffness upon exposure to warm water. Nanocomposites composed of cellulose nanocrystals (CNCs) that are grafted with a lower critical solution temperature (LCST) polymer embedded within a poly(vinyl acetate) (PVAc) matrix show a dramatic increase in modulus, for example, from 1 to 350 MPa upon exposure to warm water, the hypothesis being that grafting the polymers from the CNCs disrupts the interactions between the nanofibers and minimizes the mechanical reinforcement of the film...
August 23, 2017: ACS Central Science
https://www.readbyqxmd.com/read/28640585/thermally-and-electrically-triggered-triple-shape-memory-behavior-of-poly-vinyl-acetate-poly-lactic-acid-due-to-graphene-induced-phase-separation
#4
Mohammad Sabzi, Masoud Babaahmadi, Mohammadreza Rahnama
This work aimed to develop a facile and broadly applicable method for fabricating multistimuli responsive triple-shape memory polymers (SMPs). Hence, herein the SMPs were prepared through the simple physical blending of two commercially available biopolymers, poly(lactic acid) (PLA) and poly(vinyl acetate) (PVAc), in the presence of robust and conductive graphene nanoplatelets. Interestingly, atomic force microscopy observations and thermal analyses revealed that the presence of nanofillers led to phase separation and appearance of two well-separated transition temperatures in the blend of these two miscible polymers...
July 19, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28635284/competing-stereocomplexation-and-homocrystallization-of-poly-l-lactic-acid-poly-d-lactic-acid-racemic-mixture-effects-of-miscible-blending-with-other-polymers
#5
Jianna Bao, Xiaojia Xue, Kai Li, Xiaohua Chang, Qing Xie, Chengtao Yu, Pengju Pan
Promoting the stereocomplexation ability of high-molecular-weight poly(l-lactic acid) (PLLA) and poly(d-lactic acid) (PDLA) is an efficient way to improve the thermal resistance of the resulting materials. Herein, we studied the competing crystallization kinetics, polymorphic crystalline structure, and lamellae structure of the PLLA/PDLA component in its miscible blends with poly(vinyl acetate) (PVAc) and proposed a method to improve the stereocomplexation ability of PLLA and PDLA through miscible blending with the other polymer...
July 5, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28564367/organometallic-mediated-alternating-radical-copolymerization-of-tert-butyl-2-trifluoromethacrylate-with-vinyl-acetate-and-synthesis-of-block-copolymers-thereof
#6
Sanjib Banerjee, Vincent Ladmiral, Antoine Debuigne, Christophe Detrembleur, S M Wahidur Rahaman, Rinaldo Poli, Bruno Ameduri
Organometallic-mediated radical polymerization (OMRP) has given access to well-defined poly(vinyl acetate-alt-tert-butyl-2-trifluoromethacrylate)-b-poly(vinyl acetate) and poly(VAc-alt-MAF-TBE) copolymers composed of two electronically distinct monomers: vinyl acetate (VAc, donor, D) and tert-butyl-2-trifluoromethacrylate (MAF-TBE, acceptor, A), with low dispersity (≤1.24) and molar masses up to 57 000 g mol(-1) . These copolymers have a precise 1:1 alternating structure over a wide range of comonomer feed compositions...
August 2017: Macromolecular Rapid Communications
https://www.readbyqxmd.com/read/28496936/strategies-to-improve-safety-and-efficacy-of-atrial-fibrillation-ablation-using-electrode-multipolar-phased-rf-pvac%C3%A2-catheter-a-case-report
#7
Fabio Dorfman, Cristiano Dietrich, Paulo Costa, Evandro Sbaraini, Rafael Abt, Dalmo Moreira, Cézar Mesas
Phased radiofrequency ablation with a single catheter technique, using a 9-electrode circumferential catheter, is a viable approach to pulmonary vein isolation for the treatment of atrial fibrillation. However, creating effective transmural lesions with such technique, while avoiding serious complications like atrioesophageal fistula, can be difficult. This case illustrates a challenging scenario, where catheter maneuvers fail to allow safe radiofrequency delivery, due to esophageal temperature rise, despite extensive navigating maneuvers...
October 2016: Journal of Atrial Fibrillation
https://www.readbyqxmd.com/read/28490117/carotenoid-retention-in-biofortified-maize-using-different-post-harvest-storage-and-packaging-methods
#8
Víctor Taleon, Luke Mugode, Luisa Cabrera-Soto, Natalia Palacios-Rojas
Orange maize is being promoted as a source of provitamin A carotenoids (pVAC) in Zambia. Carotenoid retention in orange maize grains stored in metal silos, multilayer polyethylene and common woven bags, and maize meal packaged in single and multilayer polyethylene bags was evaluated. Significant differences in total pVAC retention were found between grain storage methods (48.1-57.2%) after 6months of storage. Total pVAC retention in hammer meal (73.1-73.5%) was higher than in breakfast meal (64.3-69.3%) after 4months of storage; however, no differences in pVAC retention were found between meal types when stored in single and multilayer polyethylene bags...
October 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28470057/interfacial-energy-controlled-top-coats-for-gyroid-cylinder-phase-transitions-of-polystyrene-block-polydimethylsiloxane-block-copolymer-thin-films
#9
In Hyu Ryu, Yong Joo Kim, Yeon Sik Jung, Jong Sung Lim, Caroline A Ross, Jeong Gon Son
Block copolymers (BCPs) with a high Flory-Huggins interaction parameter (χ) can form well-defined sub-10 nm periodic structures and can be used as a template for fabrication of various functional nanostructures. However, the large difference of surface energy between the blocks commonly found in high-χ BCPs makes it challenging to stabilize a useful gyroid morphology in thin film form. Here, we used an interfacial-energy-tailored top-coat on a blended film of a polystyrene-block-polydimethylsiloxane (PS-b-PDMS) BCP and a low-molecular-weight PDMS homopolymer with a hydrophilic end functional group...
May 10, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28427852/circumferential-pulmonary-vein-isolation-with-second-generation-multipolar-catheter-in-patients-with-paroxysmal-or-persistent-atrial-fibrillation-procedural-and-one-year-follow-up-results
#10
Stefan G Spitzer, Patrick Leitz, Anke Langbein, Laszlo Karolyi, Frank Scharfe, Thomas Weinmann, Carola Rämmler, Christian Pott, Gerold Mönnig, Lars Eckardt
BACKGROUND: There is a lack of procedural and follow-up data on pulmonary vein isolation (PVI) with the second-generation pulmonary vein ablation catheter® (PVAC Gold) in patients with atrial fibrillation (AF). This study provides data on PVI procedures and 1-year follow-up results with PVAC Gold in patients with AF treated in clinical practice. METHODS AND RESULTS: Three hundred and eighty four patients with documented symptomatic paroxysmal (n=198) or persistent (n=186) AF were included in a non-randomized prospectively designed database...
April 12, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28424659/online-measurement-of-microembolic-signal-burden-by-transcranial-doppler-during-catheter-ablation-for-atrial-fibrillation-results-of-a-multicenter-trial
#11
Christian von Bary, Thomas Deneke, Thomas Arentz, Anja Schade, Heiko Lehrmann, Sabine Fredersdorf, Dobri Baldaranov, Lars Maier, Felix Schlachetzki
INTRODUCTION: Left atrial pulmonary vein isolation (PVI) is an accepted treatment option for patients with symptomatic atrial fibrillation (AF). This procedure can be complicated by stroke or silent cerebral embolism. Online measurement of microembolic signals (MESs) by transcranial Doppler (TCD) may be useful for characterizing thromboembolic burden during PVI. In this prospective multicenter trial, we investigated the burden, characteristics, and composition of MES during left atrial catheter ablation using a variety of catheter technologies...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28412451/laser-treated-electrospun-fibers-loaded-with-nano-hydroxyapatite-for-bone-tissue-engineering
#12
Javier Aragon, Nuria Navascues, Gracia Mendoza, Silvia Irusta
Core-shell polycaprolactone/polycaprolactone (PCL/PCL) and polycaprolactone/polyvinyl acetate (PCL/PVAc) electrospun fibers loaded with synthesized nanohydroxyapatite (HAn) were lased treated to create microporosity. The prepared materials were characterized by XRD, FTIR, TEM and SEM. Uniform and randomly oriented beadless fibrous structures were obtained in all cases. Fibers diameters were in the 150-300nm range. Needle-like HAn nanoparticles with mean diameters of 20nm and length of approximately 150nm were mostly encase inside the fibers...
April 13, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28398439/increased-humidity-can-soften-glassy-langmuir-polymer-films-by-two-mechanisms-plasticization-of-the-polymer-material-and-suppression-of-the-evaporation-cooling-effect
#13
Hyun Chang Kim, Yun Hwa Choi, Wei Bu, Mati Meron, Binhua Lin, You-Yeon Won
Glassy Langmuir polymer films exhibit a rapid increase in surface pressure at high compression. High relative humidity typically mitigates this increase in surface pressure. In an attempt to understand the origin of this phenomenon, we investigated the effects of relative humidity on surface pressure-area isotherm properties for four different types of polymers with similar bulk glass transition temperatures: poly(d,l-lactic-co-glycolic acid) (PLGA, Tg ≈ 45 °C), poly(vinyl acetate) (PVAc, Tg ≈ 41 °C), poly(n-propyl methacrylate) (PnPMA, Tg ≈ 41 °C), and poly(vinyl stearate) (PVS, Tg ≈ 47 °C, Tm ≈ 47 °C)...
April 19, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28344498/investigation-of-the-in-vitro-performance-difference-of-drug-soluplus%C3%A2-and-drug-peg-6000-dispersions-when-prepared-using-spray-drying-or-lyophilization
#14
Mohammad A Altamimi, Steven H Neau
PURPOSE: To evaluate the physicochemical and in vitro characteristics of solid dispersions using BCS II model drugs with Soluplus® and one of its component homopolymers, PEG 6000. METHODS: Nifedipine (NIF) and sulfamethoxazole (SMX) of 99.3% and 99.5% purity, respectively, were selected as BCS II model drugs, such that an improved dissolution rate and concentration in the gastrointestinal tract should increase oral bioavailability. Soluplus® is an amorphous, tri-block, graft co-polymer with polyvinyl caprolactam, polyvinyl acetate, and polyethylene glycol (PCL:PVAc:PEG6000) in the ratio 57:30:13...
March 2017: Saudi Pharmaceutical Journal: SPJ: the Official Publication of the Saudi Pharmaceutical Society
https://www.readbyqxmd.com/read/28288375/polyvinyl-alcohol-based-hydrophilic-monoliths-from-water-in-oil-high-internal-phase-emulsion-template
#15
Xiao Meng, Ni Zeng, Jin Zhang, Long Jiang, Yi Dan
Herein, we report a new approach to fabricate polyvinyl alcohol (PVA) based hydrophilic monoliths by alcoholysis of porous emulsion-templated polyvinyl acetate (PVAc). The precursory PVAc-based monolith is obtained by polymerization of a W/O high internal phase emulsion (HIPE) containing vinyl acetate as the external phase while water as the internal phase. As an alcoholysis-stable tri-functional commonomer, triallyl isocyanurate is chosen as the crosslinking agent to prevent possible collapse of the polymeric skeleton and the consequent losses in mechanical properties during the alcoholysis step...
July 1, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28281739/cerebral-micro-embolization-during-pulmonary-vein-isolation-relation-to-post-ablation-silent-cerebral-ischemia
#16
Edina Nagy-Baló, Mihran Martirosyan, Gábor Sándorfi, Orsolya Hajas, Levente Lánczi, Ervin Berényi, Lilla Ladányi, Alexandra Kiss, István Édes, Zoltán Csanádi
BACKGROUND: High incidences of silent cerebral ischemia (SCI) have been revealed by diffusion-weighted magnetic resonance imaging (DW MRI) after pulmonary vein isolation (PVI) for atrial fibrillation. A high number of mostly gaseous micro-embolic signals (MESs) was detected by transcranial Doppler (TCD) during PVI. In this investigation the possible relationship between MESs detected intraoperatively by TCD and new SCI on DW MRI post-ablation is reported. METHODS: 27 consecutive atrial fibrillation patients (6 female, age median: 64 interquartile range: 13...
March 10, 2017: Cardiology Journal
https://www.readbyqxmd.com/read/28196659/sutures-impregnated-with-carbazate-activated-polyvinyl-alcohol-reduce-intraperitoneal-adhesions
#17
F Fredriksson, F Sellberg, T Bowden, T Engstrand, D Berglund, H E Lilja
BACKGROUND: Intraperitoneal adhesions cause significant morbidity. They occur after peritoneal trauma, which induces oxidative stress with production of inflammatory cytokines, peroxidized proteins (carbonyls) and lipids (aldehydes). This study aimed to investigate if carbazate-activated polyvinyl alcohol (PVAC), an aldehyde-carbonyl inhibitor, can reduce intraperitoneal adhesions in an experimental model. MATERIAL AND METHODS: Male Sprague-Dawley rats (n=110) underwent laparotomy, cecal abrasion and construction of a small bowel anastomosis...
February 1, 2017: Journal of Pediatric Surgery
https://www.readbyqxmd.com/read/28157325/deposition-and-characterization-of-roughened-surfaces
#18
Hagit Aviv, Shirly Berezin, Ortal Agai, Miri Sinwani, Yaakov R Tischler
Phase separation occurs whenever a solvent leaves a solution of strongly incompatible polymers. This can happen in bulk and in films. Films can be tailored as substrates for multiple applications such as solar cells, surface catalysis, and antireflection coatings. In this study, polystyrene (PS) was dissolved with polyvinyl acetate (PVAc) in different ratios using chlorobenzene as the solvent. Thin films of different ratios of PS and PVAc were deposited on glass via spin coating. The deposited films were investigated for their morphology, strain, surface area, and Raman scattering...
February 15, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28042835/a-new-determination-method-of-the-solubility-parameter-of-polymer-based-on-aie
#19
Shan Jiang, Tian Ya Huang, Ke Min Wang, Ben Zhong Tang, Qiang Yu
An accurate method of the fluorescence probe approach based on an aggregation-induced emission (AIE) molecule (tetraphenylethylene) for measuring the solubility parameter of the polymer is reported. This method is distinctive in that the approach can make the polymer chain conformation in solution be related to the fluorescence intensity. Since the solubility parameter of the polymer is also closely linked to its chain conformation in solution, the solubility parameter can be determined by the fluorescence intensity...
December 30, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28009050/factors-influencing-micronutrient-bioavailability-in-biofortified-crops
#20
REVIEW
Aurélie Bechoff, Claudie Dhuique-Mayer
Dietary and human factors have been found to be the major factors influencing the bioavailability of micronutrients, such as provitamin A carotenoid (pVAC), iron, and zinc, in biofortified crops. Dietary factors are related to food matrix structure and composition. Processing can improve pVAC bioavailability by disrupting the food matrix but can also result in carotenoid losses. By degrading antinutrients, such as phytate, processing can also enhance mineral bioavailability. In in vivo interventions, biofortified crops have been shown to be overall efficacious in reducing micronutrient deficiency, with bioconversion factors varying between 2...
February 2017: Annals of the New York Academy of Sciences
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