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https://www.readbyqxmd.com/read/28327750/dynamic-studies-of-the-interaction-of-a-ph-responsive-amphiphilic-polymer-with-a-dopc-lipid-membrane
#1
Sivaramakrishnan Ramadurai, Marco Werner, Nigel K H Slater, Aaron Martin, Vladimir A Baulin, Tia E Keyes
Deeper understanding of the molecular interactions between polymeric materials and the lipid membrane is important across a range of applications from permeation for drug delivery to encapsulation for immuno-evasion. Using highly fluidic microcavity supported lipid bilayers, we studied the interactions between amphiphilic polymer PP50 and a DOPC lipid bilayer. As the PP50 polymer is pH responsive the studies were carried out at pH 6.5, 7.05 and 7.5, corresponding to fully, partly protonated (pH = pKa = 7.05) and fully ionized states of the polymer, respectively...
March 22, 2017: Soft Matter
https://www.readbyqxmd.com/read/28320941/potent-neuroprotection-after-stroke-afforded-by-a-double-knot-spider-venom-peptide-that-inhibits-acid-sensing-ion-channel-1a
#2
Irène R Chassagnon, Claudia A McCarthy, Yanni K-Y Chin, Sandy S Pineda, Angelo Keramidas, Mehdi Mobli, Vi Pham, T Michael De Silva, Joseph W Lynch, Robert E Widdop, Lachlan D Rash, Glenn F King
Stroke is the second-leading cause of death worldwide, yet there are no drugs available to protect the brain from stroke-induced neuronal injury. Acid-sensing ion channel 1a (ASIC1a) is the primary acid sensor in mammalian brain and a key mediator of acidosis-induced neuronal damage following cerebral ischemia. Genetic ablation and selective pharmacologic inhibition of ASIC1a reduces neuronal death following ischemic stroke in rodents. Here, we demonstrate that Hi1a, a disulfide-rich spider venom peptide, is highly neuroprotective in a focal model of ischemic stroke...
March 20, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28317452/recent-advances-in-diagnostic-testing-for-gastroesophageal-reflux-disease
#3
Rishi D Naik, Michael F Vaezi
Gastroesophageal reflux disease (GERD) has a large economic burden with important complications that include esophagitis, Barrett's esophagus, and adenocarcinoma. Despite endoscopy, validated patient questionnaires, and traditional ambulatory pH monitoring, the diagnosis of GERD continues to be challenging. Areas covered: This review will explore the difficulties in diagnosing GERD with a focus on new developments, ranging from basic fundamental changes (histology and immunohistochemistry) to direct patient care (narrow-band imaging, impedance, and response to anti-reflux surgery)...
March 20, 2017: Expert Review of Gastroenterology & Hepatology
https://www.readbyqxmd.com/read/28303290/relationship-between-functional%C3%A2-endoscopy%C3%A2-and-impedance-ph%C3%A2-measurement
#4
F Michel, T Stroh, R Fritsche, P Ahrens
Classic gastroenterological diagnostic tools have proven to be insufficient in identifying the causal relationship between extra-esophageal symptoms and presumed pathological reflux activity. Some new methodological approaches, such as functional endoscopy (video panendoscopy, VPE), are considered to be helpful. However, there are currently no data objectively verifying the success of this method. In a previous study, we found a good correlation between the reflux symptom index (RSI) according to Belafsky and endoscopic findings...
March 16, 2017: HNO
https://www.readbyqxmd.com/read/28302442/symptoms-endoscopic-findings-and-reflux-monitoring-results-in-candidates-for-bariatric-surgery
#5
Benjamin Heimgartner, Marcus Herzig, Yves Borbély, Dino Kröll, Philipp Nett, Radu Tutuian
BACKGROUND: Gastroesophageal reflux disease (GERD) is common in patients with obesity. Diagnosing GERD is important as bariatric operations have different influence on GERD. We assessed reflux symptoms and objective findings prior to surgery. METHODS: Work-up included esophageal symptoms quantification by VAS-scores, esophagogastroduodenoscopy (EGD) and 24-h impedance-pH (imp-pH) monitoring off PPI therapy. Imp-pH was classified as abnormal if either %time pH<4 was abnormal, total number of reflux episodes was elevated or symptom index (SI) was positive...
February 3, 2017: Digestive and Liver Disease
https://www.readbyqxmd.com/read/28298354/determinants-of-reflux-induced-chronic-cough
#6
Thomas V K Herregods, Ans Pauwels, Jafar Jafari, Daniel Sifrim, Albert J Bredenoord, Jan Tack, André J P M Smout
OBJECTIVE: Gastro-oesophageal reflux is considered to be an important contributing factor in chronic unexplained cough. It remains unclear why some reflux episodes in the same patient causes cough while others do not. To understand more about the mechanism by which reflux induces cough, we aimed to identify factors which are important in triggering cough. DESIGN: In this multicentre study, 49 patients with reflux-associated chronic cough were analysed using 24-hour pH-impedance-pressure monitoring...
March 15, 2017: Gut
https://www.readbyqxmd.com/read/28285054/sulfonated-graphene-oxide-and-its-nanocomposites-with-electroactive-conjugated-polymer-as-effective-pseudocapacitor-electrode-materials
#7
A Ehsani, E Kowsari, F Boorboor Ajdari, R Safari, H Mohammad Shiri
In this work, we synthesized amine functionalized graphene oxide (GOA), by using of 1-methyl, 3-butyl Imidazole ionic liquid, triphenylphosphine, 1,6-diamino hexane in DMSO medium. Afterward, dried GOA used for sulfonated graphene oxide (GOS). For improving electrochemical properties of the poly ortho aminophenol (POAP), we fabricated POAP/GOS films by electro-polymerization of POAP in the presence of GOS to serve as the active electrode for electrochemical supercapacitor. Different electrochemical methods including galvanostatic charge-discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy are carried out in order to investigate the performance of the system...
March 2, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28284306/an-improved-amperometric-triglyceride-biosensor-based-on-co-immobilization-of-nanoparticles-of-lipase-glycerol-kinase-and-glycerol-3-phosphate-oxidase-onto-pencil-graphite-electrode
#8
Vinay Narwal, C S Pundir
Nanoparticles (NPs) of commercial lipase from Candida rugosa, of glycerol kinase (GK) from Cellulomonas species, of glycerol-3- phosphate oxidase (GPO) from Aerococcus viridans were prepared, characterized and co-immobilized onto a pencil graphite (PG) electrode. The morphological and electrochemical characterization of PG electrode was performed by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) before and after co-immobilization of enzyme nanoparticles (ENPs)...
May 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28272380/complexity-and-diversity-of-gerd-phenotypes
#9
Patrizia Zentilin, Elisa Marabotto, Gaia Pellegatta, Claudia Coppo, Manuele Furnari, Edoardo Savarino, Vincenzo Savarino
Gastroesophageal reflux disease (GERD) is defined as a condition which develops when the reflux of gastric contents causes troublesome symptoms, impairs quality of life, or leads to mucosal damage or complications. There are two main phenotypic presentations of GERD, the erosive (ERD) and non-erosive reflux disease (NERD), with the latter one representing up to 70% of GERD spectrum. Moreover, patients with GERD can be clinically subdivided into two distinct syndromes: patinets with esophageal and extraesophageal symptoms...
March 7, 2017: Minerva Gastroenterologica e Dietologica
https://www.readbyqxmd.com/read/28269217/non-invasive-monitoring-of-pulmonary-artery-pressure-at-the-bedside
#10
M Proenca, F Braun, E Muntane, J Sola, A Adler, M Lemay, J-Ph Thiran, S F Rimoldi
Current solutions for the monitoring of pulmonary artery pressure (PAP) in patients suffering from pulmonary hypertension are limited to invasive means. Non-invasive alternatives, such as Doppler echocardiography, are incompatible with continuous monitoring due to their dependency on qualified personnel to perform the measurements. In the present study, a novel non-invasive and unsupervised approach based on the use of electrical impedance tomography (EIT) is presented. The approach was evaluated in three healthy subjects undergoing hypoxia-induced variations in PAP...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28260352/extra-esophageal-presentation-of-gerd-new-understanding-in-a-new-era
#11
Irene Martinucci, Eleonora Albano, Santino Marchi, Corrado Blandizzi
Associations of gastroesophageal reflux disease (GERD) with extraesophageal manifestations, such as chronic cough, asthma, and laryngitis, are reported frequently, and there is a strong evidence of biological plausibility in support of this relationship. On the other hand, extraesophageal reflux disease (EERD) is usually multifactorial in nature with reflux being just one of the several potential contributing cofactors. Moreover, the accuracy of currently available diagnostic tests for EERD is suboptimal, and therefore the causal relationship between GERD and EERD remains far from being conclusively proven...
March 3, 2017: Minerva Gastroenterologica e Dietologica
https://www.readbyqxmd.com/read/28257716/the-risks-and-benefits-of-long-term-use-of-proton-pump-inhibitors-expert-review-and-best-practice-advice-from-the-american-gastroenterological-association
#12
REVIEW
Daniel E Freedberg, Lawrence S Kim, Yu-Xiao Yang
BACKGROUND & AIMS: The purpose of this review is to evaluate the risks associated with long-term use of proton pump inhibitors (PPIs), focusing on long-term use of PPIs for three common indications: gastroesophageal reflux disease (GERD), Barrett's esophagus (BE), and non-steroidal anti-inflammatory drug (NSAID) bleeding prophylaxis. METHODS: The recommendations outlined in this review are based on expert opinion and on relevant publications from PubMed, EMbase, and the Cochrane library (through July 2016)...
March 2017: Gastroenterology
https://www.readbyqxmd.com/read/28254299/alginate-copper-oxide-nano-biocomposite-as-a-novel-material-for-amperometric-glucose-biosensing
#13
Vuslat Buk, Emel Emregul, Kaan Cebesoy Emregul
A novel amperometric glucose biosensor based on alginate-CuO nano-biocomposite and glucose oxidase (GOD) film was developed and characterized. The properties of the alginate-CuO-GOD film were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Amperometric measurements were employed to characterize the analytical performance of the biosensor. Several parameters including amount of alginate, concentration of GOD and cross-linkers, amount of CuO nanoparticles, and effect of pH were studied and optimized...
May 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28251845/ppi-refractory-gerd-current-diagnosis-and-management
#14
Leonardo Frazzoni, Lorenzo Fuccio, Marzio Frazzoni
Proton pump inhibitor (PPI) therapy is the mainstay of treatment for gastroesophageal reflux disease (GERD). However, up to 30% of patients with reflux symptoms report inadequate symptom control with PPI therapy. PPI-refractory GERD should be suspected when troublesome reflux symptoms persist after 4-week standard dosage and 8-week high-dosage PPI therapy. Impedance-pH monitoring represents the gold standard for investigating the mechanism(s) of PPI refractoriness and for distinguishing patients with reflux-related from those with reflux- unrelated PPI-refractory syndromes...
March 1, 2017: Minerva Gastroenterologica e Dietologica
https://www.readbyqxmd.com/read/28247853/detection-of-electrically-neutral-and-nonpolar-molecules-in-ionic-solutions-using-silicon-nanowires
#15
Ying-Pin Wu, Chia-Jung Chu, Li-Chu Tsai, Yawen Su, Pei-Hua Chen, Mathew Moodley, Ding Huang, Yit-Tsong Chen, Ying-Jay Yang, Chii-Dong Chen
We report on a technique that can extend the use of nanowire sensors to the detection of interactions involving nonpolar and neutral molecules in ionic solution environment. This technique makes use of the fact that molecular interactions result in a change in the permittivity of the involving molecules. For the interactions taking place at the surface of nanowires, this permittivity change can be determined from the analysis of the measured nanowire complex impedance. To demonstrate this technique, histidine with different charge polarities controlled by the solutions pH value was detected, including the detection of electrically neutral histidine at a sensitivity of 1 pM...
March 1, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28240809/enzyme-based-logic-gates-and-networks-with-output-signals-analyzed-by-various-methods
#16
Evgeny Katz
The paper overviews various methods for analysis of output signals generated by enzyme-based logic systems. The considered methods include different optical techniques (optical absorbance, fluorescence spectroscopy, surface plasmon resonance), electrochemical techniques (cyclic voltammetry, potentiometry, impedance spectroscopy, conductivity measurements, use of field effect transistor devices, pH measurements), and various mechano-electronic methods (using atomic force microscope, quartz crystal microbalance)...
February 27, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28239077/a-review-of-diagnosis-of-gerd
#17
REVIEW
In Du Jeong
The prevalence of gastroesophageal reflux disease (GERD) and the incidence of some of its complications have risen strikingly over the last few decades. With the accumulation in our understanding on the pathophysiology of GERD along with the development of proton pump inhibitors, the diagnostic and therapeutic approaches to the GERD have changed dramatically over the past decade. However, The GERD still poses a problem to many clinicians since the spectrum of the disease has evolved to encompass more challenging presentations such as refractory GERD and extraesophageal manifestations...
February 25, 2017: Korean Journal of Gastroenterology, Taehan Sohwagi Hakhoe Chi
https://www.readbyqxmd.com/read/28235713/gastroesophageal-reflux-is-not-associated-with-short-term-variability-of-parasympathetic-activity-in-children
#18
Jan Krzysztof Nowak, Agata Łaźniak, Aleksandra Lisowska, Zdzisława Kycler, Waldemar Bobkowski, Jarosław Walkowiak
PURPOSE: A lower parasympathetic activity was described in patients with the gastroesophageal reflux disease. We aimed to determine whether gastroesophageal reflux (GER) episodes are associated with a short-term parasympathetic tone variability in children. METHODS: In order to address this question we performed simultaneous 24-h esophageal multichannel intraluminal impedance-pH and electrocardiographic monitoring in 16 children (age range 6-18 years), including 8 with asthma and 2 with gastroesophageal reflux disease...
February 21, 2017: Advances in Medical Sciences
https://www.readbyqxmd.com/read/28227447/non-invasive-monitoring-of-pulmonary-artery-pressure-at-the-bedside
#19
M Proenca, F Braun, E Muntane, J Sola, A Adler, M Lemay, J-Ph Thiran, S F Rimoldi, M Proenca, F Braun, E Muntane, J Sola, A Adler, M Lemay, J-Ph Thiran, S F Rimoldi, S F Rimoldi, E Muntane, J Sola, M Lemay, A Adler, J-Ph Thiran, F Braun
Current solutions for the monitoring of pulmonary artery pressure (PAP) in patients suffering from pulmonary hypertension are limited to invasive means. Non-invasive alternatives, such as Doppler echocardiography, are incompatible with continuous monitoring due to their dependency on qualified personnel to perform the measurements. In the present study, a novel non-invasive and unsupervised approach based on the use of electrical impedance tomography (EIT) is presented. The approach was evaluated in three healthy subjects undergoing hypoxia-induced variations in PAP...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28215067/epidemiology-and-natural-history-of-gastro-esophageal-reflux-disease
#20
Edoardo Savarino, Elisa Marabotto, Giorgia Bodini, Gaia Pellegatta, Claudia Coppo, Elisa Giambruno, Matteo Brunacci, Patrizia Zentilin, Vincenzo Savarino
Gastroesophageal reflux disease (GERD) is highly prevalent in Western countries, particularly when considering its most classic symptom, that is heartburn. This symptom is very frequent in the community and ranges from 10% to more than 30%, according to the various population-based studies. This disease is much more represented in Europe and US than in Asiatic countries. It has been shown that GERD prevalence increases in parallel with the remarkable growth of obesity, as this condition is able to favor all the pathogenetic mechanisms leading to it...
February 17, 2017: Minerva Gastroenterologica e Dietologica
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