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https://www.readbyqxmd.com/read/27934889/accurate-quantitative-sensing-of-intracellular-ph-based-on-self-ratiometric-upconversion-luminescent-nanoprobe
#1
Cuixia Li, Jing Zuo, Li Zhang, Yulei Chang, Youlin Zhang, Langping Tu, Xiaomin Liu, Bin Xue, Qiqing Li, Huiying Zhao, Hong Zhang, Xianggui Kong
Accurate quantitation of intracellular pH (pHi) is of great importance in revealing the cellular activities and early warning of diseases. A series of fluorescence-based nano-bioprobes composed of different nanoparticles or/and dye pairs have already been developed for pHi sensing. Till now, biological auto-fluorescence background upon UV-Vis excitation and severe photo-bleaching of dyes are the two main factors impeding the accurate quantitative detection of pHi. Herein, we have developed a self-ratiometric luminescence nanoprobe based on förster resonant energy transfer (FRET) for probing pHi, in which pH-sensitive fluorescein isothiocyanate (FITC) and upconversion nanoparticles (UCNPs) were served as energy acceptor and donor, respectively...
December 9, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27933133/pre-operative-clinical-and-instrumental-factors-as-antireflux-surgery-outcome-predictors
#2
REVIEW
Salvatore Tolone, Giorgia Gualtieri, Edoardo Savarino, Marzio Frazzoni, Nicola de Bortoli, Manuele Furnari, Giuseppina Casalino, Simona Parisi, Vincenzo Savarino, Ludovico Docimo
Gastroesophageal reflux disease (GERD) is nowadays a highly prevalent, chronic condition, with 10% to 30% of Western populations affected by weekly symptoms. Many patients with mild reflux symptoms are treated adequately with lifestyle modifications, dietary changes, and low-dose proton pump inhibitors (PPIs). For those with refractory GERD poorly controlled with daily PPIs, numerous treatment options exist. Fundoplication is currently the most commonly performed antireflux operation for management of GERD...
November 27, 2016: World Journal of Gastrointestinal Surgery
https://www.readbyqxmd.com/read/27920480/comparison-of-multichannel-intraluminal-impedance-ph-monitoring-and-reflux-scintigraphy-in-pediatric-patients-with-suspected-gastroesophageal-reflux
#3
Nuray Uslu Kızılkan, Murat Fani Bozkurt, Inci Nur Saltık Temizel, Hülya Demir, Aysel Yüce, Biray Caner, Hasan Özen
AIM: To evaluate the agreement of multichannel intraluminal impedance-pH monitoring (MII-pHM) and gastroesophageal reflux scintigraphy (GES) for the diagnosis of gastroesophageal reflux disease. METHODS: Seventy-five consecutive patients with suspected gastroesophageal reflux disease (GERD) underwent 24-h combined MII-pHM recording and one hour radionuclide scintigraphy during the course of the MII-pHM study. Catheters with 6 impedance channels and 1 pH sensor were placed transnasally...
November 21, 2016: World Journal of Gastroenterology: WJG
https://www.readbyqxmd.com/read/27914330/synergistic-effect-of-p-n-heterojunction-supporting-and-zeolite-nanoparticles-in-enhanced-photocatalytic-activity-of-nio-and-sno2
#4
Hadis Derikvandi, Alireza Nezamzadeh-Ejhieh
Increased photocatalytic activity of NiO and SnO2 was achieved by coupling and supporting of them onto clinoptilolite nanoparticles (NC) via calcination of Ni(II)-Sn(IV) - exchanged NC in photocatalytic degradation of metronidazole (MZ) aqueous solution. XRD, XRF, FTIR, SEM, X-ray mapping, DRS, TEM, BET Cyclic voltammetry and electrochemical impedance spectroscopy techniques (EIS) were used for characterization of samples. Red shift occurred in bang gap energies of the coupled semiconductors with respect to monocomponent one...
November 21, 2016: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/27911378/iridium-oxide-reduced-graphene-oxide-nanohybrid-thin-film-modified-screen-printed-electrodes-as-disposable-electrochemical-paper-microfluidic-ph-sensors
#5
Jiang Yang, Tae-Joon Kwak, Xiaodong Zhang, Robert McClain, Woo-Jin Chang, Sundaram Gunasekaran
A facile, controllable, inexpensive and green electrochemical synthesis of IrO2-graphene nanohybrid thin films is developed to fabricate an easy-to-use integrated paper microfluidic electrochemical pH sensor for resource-limited settings. Taking advantages from both pH meters and strips, the pH sensing platform is composed of hydrophobic barrier-patterned paper micropad (µPAD) using polydimethylsiloxane (PDMS), screen-printed electrode (SPE) modified with IrO2-graphene films and molded acrylonitrile butadiene styrene (ABS) plastic holder...
November 22, 2016: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/27894754/composite-of-cu-metal-nanoparticles-multiwall-carbon-nanotubes-reduced-graphene-oxide-as-a-novel-and-high-performance-platform-of-the-electrochemical-sensor-for-simultaneous-determination-of-nitrite-and-nitrate
#6
Hasan Bagheri, Ali Hajian, Mosayeb Rezaei, Ali Shirzadmehr
In the present research, we aimed to fabricate a novel electrochemical sensor based on Cu metal nanoparticles on the multiwall carbon nanotubes-reduced graphene oxide nanosheets (Cu/MWCNT/RGO) for individual and simultaneous determination of nitrite and nitrate ions. The morphology of the prepared nanocomposite on the surface of glassy carbon electrode (GCE) was characterized using various methods including scanning electron microscopy (SEM), atomic force microscopy (AFM), and electrochemical impedance spectroscopy...
November 21, 2016: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/27875359/symptom-index-or-symptom-association-probability-a-closer-look-at-symptom-association-in-suspected-gerd-patients
#7
Mustafa Abdul-Hussein, Crystal Zhang, Donald Castell
BACKGROUND: Symptom index (SI) and symptom association probability (SAP) are popular methods used to measure symptom association in patients with gastroesophageal reflux disease (GERD). AIM: To investigate whether these 2 methods yield similar results in analysis of both typical and atypical GERD symptoms. MATERIALS AND METHODS: Combined impedance-pH reflux studies of 1471 patients tested for possible GERD symptoms from January 2010 to May 2015 were reviewed...
November 21, 2016: Journal of Clinical Gastroenterology
https://www.readbyqxmd.com/read/27871613/revisiting-catechol-derivatives-as-robust-chromogenic-hydrogen-donors-working-in-alkaline-media-for-peroxidase-mimetics
#8
Marcin Drozd, Mariusz Pietrzak, Jakub Pytlos, Elżbieta Malinowska
Colloidal noble metal-based nanoparticles are able to catalyze oxidation of chromogenic substrates by H2O2, similarly to peroxidases, even in basic media. However, lack of robust chromogens, which work in high pH impedes their real applications. Herein we demonstrate the applicability of selected catechol derivatives: bromopyrogallol red (BPR) and pyrogallol (PG) as chromogenic substrates for peroxidase-like activity assays, which are capable of working over wide range of pH, covering also basic values. Hyperbranched polyglycidol-stabilized gold nanoparticles (HBPG@AuNPs) were used as model enzyme mimetics...
December 15, 2016: Analytica Chimica Acta
https://www.readbyqxmd.com/read/27871380/an-improved-amperometric-l-lactate-biosensor-based-on-covalent-immobilization-of-microbial-lactate-oxidase-onto-carboxylated-multiwalled-carbon-nanotubes-copper-nanoparticles-polyaniline-modified-pencil-graphite-electrode
#9
Kusum Dagar, C S Pundir
An improved amperometric l-lactate biosensor was constructed based on covalent immobilization of lactate oxidase (LOx) from Pediococcus species onto carboxylated multiwalled carbon nanotubes (cMWCNT)/copper nanoparticles (CuNPs)/polyaniline (PANI) hybrid film electrodeposited on the surface of a pencil graphite electrode (PGE). The enzyme electrode was characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and electrochemical impedance spectroscopy (EIS), while CuNPs synthesized by chemical reduction method, were characterized by transmission electron microscopy (TEM), UV spectrascopy and X-ray diffraction (XRD)...
January 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/27870951/simultaneous-determination-of-trace-cd-ii-pb-ii-and-cu-ii-by-differential-pulse-anodic-stripping-voltammetry-using-a-reduced-graphene-oxide-chitosan-poly-l-lysine-nanocomposite-modified-glassy-carbon-electrode
#10
Zhuo Guo, Dong-di Li, Xian-Ke Luo, Ya-Hui Li, Qi-Nai Zhao, Meng-Meng Li, Yang-Ting Zhao, Tian-Shuai Sun, Chi Ma
The reduced graphene oxide (RGO) and Chitosan (CS) hybrid matrix RGO-CS were coated onto the glassy carbon electrode (GCE) surface, then, poly-l-lysine films (PLL) were prepared by electropolymerization with cyclic voltammetry (CV) method to prepare RGO-CS/PLL modified glassy carbon electrode (RGO-CS/PLL/GCE) for the simultaneous electrochemical determination of heavy metal ions Cd(II), Pb(II) and Cu(II). Combining the advantageous features of RGO and CS, RGO and CS are used together because the positively charged CS can interact with the negatively changed RGO to prevent their aggregation...
November 2, 2016: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/27866273/omeprazole-suppressed-plasma-magnesium-level-and-duodenal-magnesium-absorption-in-male-sprague-dawley-rats
#11
Narongrit Thongon, Jirawat Penguy, Sasikan Kulwong, Kanyanat Khongmueang, Matthana Thongma
Hypomagnesemia is the most concerned side effect of proton pump inhibitors (PPIs) in chronic users. However, the mechanism of PPIs-induced systemic Mg(2+) deficit is currently unclear. The present study aimed to elucidate the direct effect of short-term and long-term PPIs administrations on whole body Mg(2+) homeostasis and duodenal Mg(2+) absorption in rats. Mg(2+) homeostasis was studied by determining the serum Mg(2+) level, urine and fecal Mg(2+) excretions, and bone and muscle Mg(2+) contents. Duodenal Mg(2+) absorption as well as paracellular charge selectivity were studied...
November 2016: Pflügers Archiv: European Journal of Physiology
https://www.readbyqxmd.com/read/27865700/adhesion-ability-of-angiotensin-ii-with-model-membranes
#12
Julia Preu, Louis Tiefenauer, Thomas Gutberlet
The octa-peptide angiotensin II (Ang II, (H2NAspArgValTyrIleHisProPheCOOH)) is one of the key player on blood pressure regulation in mammals. Predominantly binding to the Angiotensin type 1 and 2 receptors, the hormone is one of several peptide ligands binding to G protein coupled receptors (GPCR). The active hormone derives from a high molecular weight precursor sequentially cleaved by the proteases renin and the angiotensin converting enzyme (ACE). The chemical nature of the amino acid sequence has an impact on the behavior in the proximity of membranes, demonstrated using different membrane model systems and biophysical methods...
November 17, 2016: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/27852360/-changes-and-implications-of-esophageal-function-in-patients-with-chronic-cough-induced-by-gastroesophageal-reflux
#13
X H Xu, L Yu, Q Chen, Y Huang, H H Sun, L S Yi, S C Xu, H J Lyu, Z M Qiu
Objective: To explore the changes in the esophageal function and their association with the therapeutic outcome in patients with gastroesophageal reflux-induced chronic cough (GERC). Methods: One hundred thirty-five patients with definite GERC consecutively referred to our respiratory clinic were recruited into the study between January 2012 and August 2015.Cough was due to acid reflux in 81 patients and non-acid reflux in 54 patients, with the favorable response to the standard antireflux therapy in 88 patients and to the intensified antireflux treatment in 47 patients...
November 12, 2016: Chinese Journal of Tuberculosis and Respiratory Diseases
https://www.readbyqxmd.com/read/27845720/a-novel-application-for-low-frequency-electrochemical-impedance-spectroscopy-as-an-online-process-monitoring-tool-for-viable-cell-concentrations
#14
Christoph Slouka, David J Wurm, Georg Brunauer, Andreas Welzl-Wachter, Oliver Spadiut, Jürgen Fleig, Christoph Herwig
New approaches in process monitoring during industrial fermentations are not only limited to classical pH, dO₂ and offgas analysis, but use different in situ and online sensors based on different physical principles to determine biomass, product quality, lysis and far more. One of the very important approaches is the in situ accessibility of viable cell concentration (VCC). This knowledge provides increased efficiency in monitoring and controlling strategies during cultivations. Electrochemical impedance spectroscopy-EIS-is used to monitor biomass in a fermentation of E...
November 11, 2016: Sensors
https://www.readbyqxmd.com/read/27810129/influence-of-saos-2-cells-on-corrosion-behavior-of-cast-mg-2-0zn0-98mn-magnesium-alloy
#15
Agnieszka Witecka, Akiko Yamamoto, Wojciech Święszkowski
In this research, the effect of the presence of living cells (SaOS-2) on in vitro degradation of Mg-2.0Zn-0.98Mn (ZM21) magnesium alloy was examined by two methods simple immersion/cell culture tests and electrochemical measurements (electrochemical impedance spectroscopy and potentiodynamic polarization) under cell culture conditions. In immersion/cell culture tests, when SaOS-2 cells were cultured on ZM21 samples, pH of cell culture medium decreased, therefore weight loss and Mg(2+) ion release from the samples increased...
October 25, 2016: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/27808009/novel-spray-dried-ph-sensitive-polyacrylamide-grafted-carboxymethylcellulose-sodium-copolymer-microspheres-for-colon-targeted-delivery-of-an-anti-cancer-drug
#16
Vijaykumar V Alange, Ravindra P Birajdar, Raghavendra V Kulkarni
Unique pH-sensitive spray dried microspheres were formulated employing hydrolyzed polyacrylamide-g-carboxymethylcellulose sodium (PAAm-g-NaCMC) co-polymer for colon targeted delivery of an anticancer drug, capecitabine. Synthesis of PAAm-g-NaCMC was carried out through free radical polymerization, which was supported with an inert atmosphere and then the alkaline hydrolysis was performed and subjected for characterization including FTIR spectroscopic analysis, (1)H NMR spectroscopic analysis, elemental analysis, viscosity measurement, neutralization equivalent and thermo-gravimetric investigation...
November 21, 2016: Journal of Biomaterials Science. Polymer Edition
https://www.readbyqxmd.com/read/27805610/applications-of-phluorin-for-quantitative-kinetic-and-high-throughput-analysis-of-endocytosis-in-budding-yeast
#17
Derek C Prosser, Kristie Wrasman, Thaddeus K Woodard, Allyson F O'Donnell, Beverly Wendland
Green fluorescent protein (GFP) and its variants are widely used tools for studying protein localization and dynamics of events such as cytoskeletal remodeling and vesicular trafficking in living cells. Quantitative methodologies using chimeric GFP fusions have been developed for many applications; however, GFP is somewhat resistant to proteolysis, thus its fluorescence persists in the lysosome/vacuole, which can impede quantification of cargo trafficking in the endocytic pathway. An alternative method for quantifying endocytosis and post-endocytic trafficking events makes use of superecliptic pHluorin, a pH-sensitive variant of GFP that is quenched in acidic environments...
October 23, 2016: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/27804042/esophageal-mucosal-integrity-improves-after-laparoscopic-antireflux-surgery-in-children-with-gastroesophageal-reflux-disease
#18
Femke A Mauritz, Nicolaas F Rinsma, Ernest L W van Heurn, Cornelius E J Sloots, Peter D Siersema, Roderick H J Houwen, David C van der Zee, Ad A M Masclee, José M Conchillo, Maud Y A Van Herwaarden-Lindeboom
BACKGROUND: Esophageal intraluminal baseline impedance reflects the conductivity of the esophageal mucosa and may be an instrument for in vivo evaluation of mucosal integrity in children with gastroesophageal reflux disease (GERD). Laparoscopic antireflux surgery (LARS) is a well-established treatment option for children with proton pump inhibitory (PPI) therapy resistant GERD. The effect of LARS in children on baseline impedance has not been studied in detail. The aim of this study was to evaluate the effect of LARS on baseline impedance in children with GERD...
November 1, 2016: Surgical Endoscopy
https://www.readbyqxmd.com/read/27799782/cancer-fundamentals-behind-ph-targeting-and-the-double-edged-approach
#19
Tomas Koltai
The highly regulated pH of cells and the less-regulated pH of the surrounding extracellular matrix (ECM) is the result of a delicate balance between metabolic processes and proton production, proton transportation, chemical buffering, and vascular removal of waste products. Malignant cells show a pronounced increase in metabolic processes where the 10- to 15-fold rise in glucose consumption is only the tip of the iceberg. Aerobic glycolysis (Warburg effect) is one of the hallmarks of cancer metabolism that implies excessive production of protons, which if stayed inside the cells would result in fatal intracellular acidosis (maintaining a strict acid-base balance is essential for the survival of eukaryotic cells)...
2016: OncoTargets and Therapy
https://www.readbyqxmd.com/read/27796439/applying-pathway-engineering-to-enhance-production-of-alpha-ketoglutarate-in-yarrowia-lipolytica
#20
REVIEW
Hongwei Guo, Shaojie Su, Catherine Madzak, Jingwen Zhou, Hongwen Chen, Guo Chen
α-Ketoglutarate (α-KG), one of short-chain carboxylates of high commercial relevance, has been widely used in food, medicine, chemical, and cosmetic fields. Compared to other carboxylates, α-KG occupies key positions in the tricarboxylate cycle (TCA cycle) and amino acid metabolic pathway, the over-accumulation of α-KG is restricted both by tighter carbon and nitrogen regulation process. Biotechnology production of α-KG on large industrial level has been impeded by many obstacles. This review aims at highlighting and stating recent efforts toward improving the yield and titer of α-KG in the strains of Yarrowia lipolytica to reach industrial relevance...
October 29, 2016: Applied Microbiology and Biotechnology
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