Read by QxMD icon Read

Ph Impedance

K Ravi, D M Geno, M F Vela, M D Crowell, D A Katzka
BACKGROUND: Baseline impedance measured with ambulatory impedance pH monitoring (MII-pH) and a mucosal impedance catheter detects gastroesophageal reflux disease (GERD). However, these tools are limited by cost or patient tolerance. We investigated whether baseline impedance measured during high-resolution impedance manometry (HRIM) distinguishes GERD patients from controls. METHODS: Consecutive patients with clinical HRIM and MII-pH testing were identified. Gastroesophageal reflux disease was defined by esophageal pH <4 for ≥5% of both the supine and total study time, whereas controls had an esophageal pH <4 for ≤3% of the study performed off PPI...
October 24, 2016: Neurogastroenterology and Motility: the Official Journal of the European Gastrointestinal Motility Society
Lei Mei, Guizhi Zhu, Liping Qiu, Cuichen Wu, Huapei Chen, Hao Liang, Sena Cansiz, Yifan Lv, Xiaobing Zhang, Weihong Tan
Cancer chemotherapy has been impeded by side effects and multidrug resistance (MDR) partially caused by drug efflux from cancer cells, which call for targeted drug delivery systems additionally able to circumvent MDR. Here we report multifunctional DNA nanoflowers (NFs) for targeted drug delivery to both chemosensitive and MDR cancer cells and circumvent MDR in both leukemia and breast cancer cell models. NFs are self-assembled via liquid crystallization of DNA generated by Rolling Circle Replication, during which NFs are incorporated with aptamers for specific cancer cell recognition, fluorophores for bioimaging, and Doxorubicin (Dox)-binding DNA for drug delivery...
November 2015: Nano Research
Miguel Couselo, Vicente Ibáñez, Javier Lluna, Juan José Vila
Introduction Low values of esophageal impedance baseline (EIB) have been related to esophagitis. The aim of this study was to evaluate the diagnostic performance of EIB for erosive esophagitis (ErE) and histological esophagitis (HiE) in children studied for gastroesophageal reflux. Material and Methods Children who underwent esophageal multichannel intraluminal impedance-pH monitoring (MII-pH) and upper-endoscopy with esophageal biopsies were studied retrospectively. EIB values were obtained by MII-pH. ErE was assessed by endoscopy following the Hetzel-Dent classification; HiE was defined by basal zone hyperplasia, papillary lengthening, or inflammatory infiltration...
October 21, 2016: European Journal of Pediatric Surgery
Muhammad Rafehi, Joachim C Burbiel, Isaac Y Attah, Aliaa Abdelrahman, Christa E Müller
The Gq protein-coupled, ATP- and UTP-activated P2Y2 receptor is a potential drug target for a range of different disorders, including tumor metastasis, inflammation, atherosclerosis, kidney disorders, and osteoporosis, but pharmacological studies are impeded by the limited availability of suitable antagonists. One of the most potent and selective antagonists is the thiouracil derivative AR-C118925. However, this compound was until recently not commercially available and little is known about its properties...
October 20, 2016: Purinergic Signalling
Amany M Fekry
A new sensitive simple electrochemical sensor for Moxifloxacin Hydrochloride (MOXI) detection has been successfully performed. The sensor built on carbon paste (CP) modified with silver nanoparticles (AgNPs). AgNPs are biocompatible stable noble materials especially in biological sensing. The silver nanoparticles modified carbon paste electrode (SNMCPE) displayed high electrocatalytic activity towards oxidation of 1.0mM MOXI in Britton Robinson (BR) buffer of pH range (2.0-9.0). The techniques used to do this work are cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS)...
July 25, 2016: Biosensors & Bioelectronics
Letizia Zenzeri, Paolo Quitadamo, Renato Tambucci, Dario Ummarino, Antonio Poziello, Erasmo Miele, Annamaria Staiano
OBJECTIVES: Respiratory symptoms are a possible atypical clinical picture of gastro-esophageal reflux disease (GERD). However, a significant number of patients with GERD-related respiratory symptoms do not report improvement despite aggressive acid-suppressive therapy. Some of these refractory cases may be due to the recently appreciated entity of non-acid or weakly acidic reflux. The aim of our study is to assess the pH-impedance features of GER inducing airway symptoms, compared with GER inducing typical gastro-intestinal (GI) symptoms...
October 13, 2016: Pediatric Pulmonology
Lucia Becucci, Giovanni Aloisi, Rolando Guidelli
Melittin exhibits an ohmic behavior in a lipid bilayer having a DOPC distal leaflet and interposed between a 2.25nm tetraethyleneoxy chain tethered to a mercury drop and an aqueous solution. This behavior is induced in a pH6.8 buffer solution of 0.8μg/mL melittin by a pretreatment consisting of series of electrochemical impedance spectroscopy measurements at bias potentials varied by 50mV steps over a transmembrane potential range from about +250 to -250mV. This metastable ohmic behavior remains unchanged for hours, even after acidifying the solution to pH3...
October 6, 2016: Bioelectrochemistry
Ivan Pavić, Irena Babić, Jasna Čepin Bogović, Iva Hojsak
OBJECTIVE: The aim of this study was to investigate the diagnostic usefulness of combined multichannel intraluminal impedance-pH (MII-pH) monitoring in children with suspected laryngopharyngeal reflux (LPR). DESIGN, SETTING AND PARTICIPANTS: A prospective study including children in whom, due to LPR suggestive symptoms, MII-pH monitoring was performed at tertiary medical center from February 2012 to July 2015. INTERVENTIONS: All included children underwent same diagnostic protocol which included examination by single pulmonologist, ENT specialist and underwent 24-h MII-pH monitoring...
October 11, 2016: Clinical Otolaryngology
Zhiyong Xie, Juncui Xu, Fazhi Xie, Shiquan Xiong
A reduced graphene oxide (rGO)/Fe3O4 composites modified screen-printed carbon electrode (SPCE) was used to determinate As(III) in a HAc-NaAc buffer solution. The rGO/Fe3O4 composites were prepared by a simple and one-pot synthesis method, and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), FT-IR and Raman spectra. The electrochemical behaviors of the composite electrode were characterized by cycle voltammetry and electrochemical impedance spectroscopy. The experimental parameters, such as supporting electrolyte, solution pH, deposition potential, deposition time were optimized, respectively...
2016: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Xiaofang Zhang, Wenjing Lin, Liyang Wen, Na Yao, Shuyu Nie, Lijuan Zhang
Unimolecular polymeric micelles have several features, such as thermodynamic stability, small particle size, biocompatibility, and the ability to internalize hydrophobic molecules. These micelles have recently attracted significant attention in various applications, such as nano-reactors, catalysis, and drug delivery. However, few attempts have explored the formation mechanisms and conditions of unimolecular micelles due to limited experimental techniques. In this study, a unimolecular micelle system formed from β-cyclodextrin-graft-{poly(lactide)-block-poly(2-(dimethylamino) ethyl multimethacrylate)-block-poly[oligo (2-ethyl-2-oxazoline) methacrylate]} β-CD-g-(PLA-b-PDMAEMA-b-PEtOxMA) star-like block copolymers in aqueous media was investigated by dissipative particle dynamics (DPD) to explore the formation process of unimolecular micelles...
September 29, 2016: Physical Chemistry Chemical Physics: PCCP
Janani Sankaran, Aslam H Qureshi, Frederick Woodley, Mark Splaingard, Sudarshan R Jadcherla
OBJECTIVES: To describe the pattern of gastroesophageal reflux (GER) events in wake and sleep states with increasing acid reflux index (ARI) in neonates and to test the hypothesis that GER-related symptoms are frequent in ARI >7% in wake state. STUDY DESIGN: Infants underwent 24-hour pH-impedance studies with 6-hour concurrent video-polysomnography studies. Data were stratified based on the 24-hour ARI (% duration that esophageal pH is <4) into ARI < 3% (normal), ARI 3 ≥ to ≤7% (intermediate), and ARI >7% (abnormal)...
September 27, 2016: Journal of Pediatrics
Wenyi Wang, Patrick C L Hui, Elaine Wat, Frency S F Ng, Chi-Wai Kan, Xiaowen Wang, Eric C W Wong, Huawen Hu, Ben Chan, Clara B S Lau, Ping-Chung Leung
For the treatment of atopic dermatitis (AD), we have developed a transdermal functionalized textile therapy based on thermosensitive poloxamer 407 (P407) hydrogel containing a traditional Chinese herbal medicine. This study aims to investigate the effects of various formulation variables of P407/carboxymethyl cellulose sodium (P407/CMCs) composite hydrogel on the release of Cortex Moutan (CM) extract. Concentrations of P407 and CMCs showed significant influence on the release due to alteration of bulk viscosity of the system...
September 23, 2016: Colloids and Surfaces. B, Biointerfaces
Poornachandra Papireddy Vinayaka, Sander van den Driesche, Roland Blank, Muhammad Waseem Tahir, Mathias Frodl, Walter Lang, Michael J Vellekoop
A new miniaturized sensor system with an internal optical reference for the detection of mold growth is presented. The sensor chip comprises a reaction chamber provided with a culture medium that promotes the growth of mold species from mold spores. The mold detection is performed by measuring impedance changes with integrated electrodes fabricated inside the reaction chamber. The impedance change in the culture medium is caused by shifts in the pH (i.e., from 5.5 to 8) as the mold grows. In order to determine the absolute pH value without the need for calibration, a methyl red indicator dye has been added to the culture medium...
2016: Sensors
M M J Singendonk, M A Benninga, M P van Wijk
Recently, multichannel intraluminal impedance (MII) monitoring was added to the repertoire of tests to evaluate the (patho)physiology of gastroesophageal reflux (GER) in children. Its advantage above the sole monitoring of the esophageal pH lies in the ability of the detection of both acid and nonacid GER and to discern between liquid and gas GER. Currently, combined 24 h pH-MII monitoring is recommended for evaluation of gastro-esophageal reflux disease (GERD) and its relation to symptoms in infants and children, despite the lack of reference values in these age groups...
October 2016: Neurogastroenterology and Motility: the Official Journal of the European Gastrointestinal Motility Society
Edoardo Savarino, Andrea Ottonello, Salvatore Tolone, Ottavia Bartolo, Myong Ki Baeg, Farhood Farjah, Shiko Kuribayashi, Katerina P Shetler, Christian Lottrup, Ellen Stein
The 21st century offers new advances in diagnostic procedures and protocols in the management of esophageal diseases. This review highlights the most recent advances in esophageal diagnostic technologies, including clinical applications of novel endoscopic devices, such as ultrathin endoscopy and confocal laser endomicroscopy for diagnosis and management of Barrett's esophagus; novel parameters and protocols in high-resolution esophageal manometry for the identification and better classification of motility abnormalities; innovative connections between esophageal motility disorder diagnosis and detection of gastroesophageal reflux disease (GERD); impedance-pH testing for detecting the various GERD phenotypes; performance of distensibility testing for better pathophysiological knowledge of the esophagus and other gastrointestinal abnormalities; and a modern view of positron emission tomography scanning in metastatic disease detection in the era of accountability as a model for examining other new technologies...
September 28, 2016: Annals of the New York Academy of Sciences
Jacques-Philippe Colletier, Michael R Sawaya, Mari Gingery, Jose A Rodriguez, Duilio Cascio, Aaron S Brewster, Tara Michels-Clark, Robert H Hice, Nicolas Coquelle, Sébastien Boutet, Garth J Williams, Marc Messerschmidt, Daniel P DePonte, Raymond G Sierra, Hartawan Laksmono, Jason E Koglin, Mark S Hunter, Hyun-Woo Park, Monarin Uervirojnangkoorn, Dennis K Bideshi, Axel T Brunger, Brian A Federici, Nicholas K Sauter, David S Eisenberg
BinAB is a naturally occurring paracrystalline larvicide distributed worldwide to combat the devastating diseases borne by mosquitoes. These crystals are composed of homologous molecules, BinA and BinB, which play distinct roles in the multi-step intoxication process, transforming from harmless, robust crystals, to soluble protoxin heterodimers, to internalized mature toxin, and finally to toxic oligomeric pores. The small size of the crystals-50 unit cells per edge, on average-has impeded structural characterization by conventional means...
September 28, 2016: Nature
Simon Nennstiel, Mack Andrea, Mohamed Abdelhafez, Bernhard Haller, Roland M Schmid, Monther Bajbouj, Valentin Becker
BACKGROUND AND STUDY AIM: Optimal therapy concepts in patients with laryngo-pharyngeal reflux (LPR) are still under discussion. Aim of this study was to evaluate long term symptom relief according to results in combined pH/multichannel impedance (MII) monitoring to predict therapy response and symptom relief during long term follow-up. PATIENTS AND METHODS: In patients with predominant LPR symptoms, pH/MII monitoring and subsequent proton pump inhibitor (PPI) therapy were evaluated retrospectively after a minimum follow-up period of 36months...
September 2016: Arab Journal of Gastroenterology: the Official Publication of the Pan-Arab Association of Gastroenterology
Charles G Cranfield, Thomas Berry, Stephen A Holt, Khondker R Hossain, Anton P Le Brun, Sonia Carne, Heba Al Khamici, Hans Coster, Stella M Valenzuela, Bruce Cornell
This study explains the importance of the phosphate moiety and H3O(+) in controlling the ionic flux through phospholipid membranes. We show that despite an increase in the H3O(+) concentration when the pH is decreased, the level of ionic conduction through phospholipid bilayers is reduced. By modifying the lipid structure, we show the dominant determinant of membrane conduction is the hydrogen bonding between the phosphate oxygens on adjacent phospholipids. The modulation of conduction with pH is proposed to arise from the varying H3O(+) concentrations altering the molecular area per lipid and modifying the geometry of conductive defects already present in the membrane...
October 4, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Suryasnata Tripathy, Aniket Ramesh Ghole, Khandavalli Deep, Siva Rama Krishna Vanjari, Shiv Govind Singh
This paper proposes a novel milk quality detection approach based on utilization of inherent biophysical properties as 'markers' for adulteration. Unlike the traditional adulterant-specific approaches, this method is generic and universal. It exploits the change in innate milk properties, such as electrical conductivity and pH, upon addition of adulterants as a transduction mechanism for detecting milk adulteration. In this work, adulteration with more than 10 commercially known hazardous adulterants is detected by monitoring the changes in milk electrical conductivity and pH...
February 15, 2017: Food Chemistry
Li-Na Meng, Shanshan Chen, Jiande D Z Chen, Hai-Feng Jin, Bin Lu
Objective. To investigate effects and possible mechanisms of transcutaneous electrical acustimulation (TEA) performed by a wearable watch-size stimulator for refractory gastroesophageal reflux disease (RGERD). Methods. Twenty patients diagnosed as RGERD were enrolled in the study and randomly divided into four groups: esomeprazole group (Group A), esomeprazole combined with TEA group (Group B), esomeprazole combined with sham-TEA group (Group C), and esomeprazole combined with domperidone group (Group D). HRM and 24 h pH-impedance monitoring and GerdQ score were used to measure related indexes before and after treatment...
2016: Evidence-based Complementary and Alternative Medicine: ECAM
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"