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Ph Impedance

Xing Du, Feng Wang, Zhiwei Hu, Jimin Wu, Zhonggao Wang, Chao Yan, Chao Zhang, Juan Tang
BACKGROUND: None of current diagnostic methods has been proven to be a reliable tool for gastro-esophageal reflux disease (GERD). Pepsin in saliva has been proposed as a promising diagnostic biomarker for gastro-esophageal reflux. We aimed to determine the diagnostic value of salivary pepsin detection for GERD. METHODS: Two hundred and fifty patients with symptoms suggestive of GERD and 35 asymptomatic healthy volunteers provided saliva on morning waking, after lunch and dinner for pepsin determination using the Peptest lateral flow device...
October 17, 2017: BMC Gastroenterology
Kathiresan Vijayaraj, Thirumalai Dinakaran, Yujeong Lee, Suhkmann Kim, Hyung Sik Kim, Jaewon Lee, Seung-Cheol Chang
We developed a new strategy for construction of a biosensor for the neurotransmitter dopamine. The biosensor was constructed by one-step electrochemical deposition of a nanocomposite in aqueous solution at pH 7.0, consisting of molybdenum disulfide, multi-walled carbon nanotubes, and polypyrrole. A series of analytical methods was performed to investigate the surface characteristics and the improved electrocatalytic effect of the nanocomposite, including cyclic voltammetry, electrochemical impedance spectroscopy, field-emission scanning electron microscopy, atomic force microscopy, and Raman spectroscopy...
October 13, 2017: Biochemical and Biophysical Research Communications
T V K Herregods, A Pauwels, J Jafari, D Sifrim, A J P M Smout, A J Bredenoord, J Tack
Gastroesophageal reflux is considered to be a significant contributing factor to chronic unexplained cough. Patients are often presumed to have reflux-induced cough and are exposed to high-dose and long-term empirical therapy with proton pump inhibitors (PPIs) despite the limited treatment efficacy in this population. We aimed to assess the diagnostic value of 24-hour ambulatory pH-impedance-pressure monitoring for the diagnosis of reflux-induced chronic cough. In this multicenter study, we evaluated 192 patients with chronic cough using 24-hour pH-impedance-pressure monitoring off PPIs...
September 27, 2017: Diseases of the Esophagus: Official Journal of the International Society for Diseases of the Esophagus
Zhenpeng Hu, Jinlong Ma, Fei Fu, Chen Cui, Xiaomin Li, Xinyu Wang, Wei Wang, Yeda Wan, Zhi Yuan
Programmed ligand targeting strategy promotes the blood circulation stability of nanoparticles by shielding the ligand. However, the irreversible shielding causes the deshielded nanoparticles to be easily recognized and cleared by the reticuloendothelial system (RES), impeding their further retention in the tumor. Here, we for the first time prove the superiority of the intelligent re-shieldable targeting system that is based on the pH-responsive self-assembly/disassembly of gold nanoparticles. The system can enhance the stability of gold nanoparticles in the blood circulation (2...
October 13, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
Radhakanta Ghosh, Dhruba P Chatterjee, Sujoy Das, Titas Kumar Mukhopadhyay, Ayan Datta, Arun K Nandi
A significant tuning of optoelectronic properties of polythiophene (PT) chains due to Hofmeister iodide (I-) ion is demonstrated in ampholytic polythiophene [polythiophene-g-poly{(N,N,N-trimethylamino iodide)ethyl methacrylate-co-methacrylic acid}, APT] at different pH. In acidic medium, the absorption and emission signals of PT chromophore exhibit appreciable blue shift in presence of I- as counter anion only. The co-operative effect of undissociated -COOH and quaternary ammonium groups immobilize I- near apolar PT chain causing threading of grafted chains and hence twisting of the backbone attributing to the blue shift...
October 13, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Frederick W Woodley, Melissa Moore-Clingenpeel, Rodrigo Strehl Machado, Christopher J Nemastil, Sudarshan R Jadcherla, Don Hayes, Benjamin T Kopp, Ajay Kaul, Carlo Di Lorenzo, Hayat Mousa
PURPOSE: Acid neutralization during chemical clearance is significantly prolonged in children with cystic fibrosis, compared to symptomatic children without cystic fibrosis. The absence of available reference values impeded identification of abnormal findings within individual patients with and without cystic fibrosis. The present study aimed to test the hypothesis that significantly more children with cystic fibrosis have acid neutralization durations during chemical clearance that fall outside the physiological range...
September 2017: Pediatric Gastroenterology, Hepatology & Nutrition
Feng Gao, Yan Gao, Xue Chen, Jie Qian, Jie Zhang
OBJECTIVE: To investigate the differences in the results of esophageal function tests for functional heartburn (FH) and reflux hypersensitivity (RH). METHODS: Patients with FH and RH and healthy volunteers (HVs) from the Department of Gastroenterology, Beijing Anzhen Hospital and Beijing Chao-Yang hospital, who underwent high-resolution manometry and impedance (HRIM), and 24-hour multichannel intraluminal impedance and pH recording (MII/pH) between 2014 and 2016, were enrolled in this study...
2017: Gastroenterology Research and Practice
Thomas V K Herregods, Albert J Bredenoord, Jacobus M Oors, Auke Bogte, André J P M Smout
OBJECTIVES: Gastroesophageal reflux is considered to be the most common gastrointestinal cause of non-cardiac chest pain (NCCP). It remains unclear why some reflux episodes in the same patient cause chest pain while others do not. To understand more about the mechanisms by which reflux elicits chest pain, we aimed to identify factors which are important in triggering chest pain. METHODS: In this multicenter study, 120 patients with NCCP were analyzed using 24-h pH-impedance monitoring...
October 10, 2017: American Journal of Gastroenterology
Jun Seok Lee, Ah Ra Jung, Jung Min Park, Myung Jin Park, Young Chan Lee, Young-Gyu Eun
Objectives: To analyze laryngopharyngeal reflux (LPR) as an acidic, nonacidic, or mixed type according to 24-hour multichannel intraluminal impedance (MII) pH monitoring and the clinical characteristics of each type. Methods: Ninety patients were prospectively enrolled in this study. All patients underwent 24-hour MII pH monitoring as a diagnostic tool. Eighty-three patients were diagnosed with LPR. The patients were classified into three groups according to the pH of the hypopharyngeal probe: the acid reflux group, nonacid reflux group, and mixed reflux group...
October 10, 2017: Clinical and Experimental Otorhinolaryngology
Yu-Wen Li, Daniel Sifrim, Chenxi Xie, Minhu Chen, Ying-Lian Xiao
Background/Aims: Increased salivary pepsin could indicate an increase in gastro-esophageal reflux, however, previous studies failed to demonstrate a correlation between salivary pepsin concentrations and 24-hour esophageal acid exposure. This study aims to detect the salivary pepsin and to evaluate the relationship between salivary pepsin concentrations and intercellular spaces (IS) in different gastroesophageal reflux disease phenotypes in patients. Methods: A total of 45 patients and 11 healthy volunteers were included in this study...
October 30, 2017: Journal of Neurogastroenterology and Motility
Takahisa Yamasaki, Ronnie Fass
Reflux hypersensitivity, recently introduced by Rome IV as a new functional esophageal disorder, is currently considered as the presence of typical heartburn symptoms in patients with normal upper endoscopy and esophageal biopsies, normal esophageal pH test and with evidence of a close correlation between patients' heartburn and reflux events. Reflux hypersensitivity is very common and together with functional heartburn accounts for more than 90% of the heartburn patients who failed treatment with proton pump inhibitor twice daily...
October 30, 2017: Journal of Neurogastroenterology and Motility
Hongmei Jiao, Ling Mei, Chenyang Liang, Yun Dai, Zhifang Fu, Lihong Wu, Patrick Sanvanson, Reza Shaker
OBJECTIVES/HYPOTHESIS: Aspiration of gastric refluxate is one of the most commonly observed complications among long-term nasogastric tube (NGT) fed patients. The upper esophageal sphincter (UES) pressure barrier is the main defense mechanism against pharyngeal reflux of gastric contents. Our objective was to investigate the efficacy and safety of the UES assist device (UES-AD) in preventing gastric reflux through the UES in long-term NGT-fed patients. STUDY DESIGN: Self-Controlled Case series...
October 8, 2017: Laryngoscope
Nan Nan Xia, Xiaomin Xiong, Min Zhi Rong, Ming Qiu Zhang, Fangong Kong
To improve reliability, durability and re-workability of bulk polymers utilized in ubiquitous acidic water, the authors develop a novel hyperbranched polymer capable of self-healing and recycling in low pH aqueous environment. The hyperbranched polymer has many hydrophilic and hydrophobic terminal groups. When it is damaged in acidic water, the hydrophilic groups are protonated, forming hydrogen bonds, and closing the crack. Meantime, hydrophobic interactions of hydrophobic groups are gradually established across the interface due to the intimate contact of cracked surface, further reinforcing the re-bonded portion...
October 6, 2017: ACS Applied Materials & Interfaces
Aysu Yarman, Sevinc Kurbanoglu, Katharina J Jetzschmann, Sibel A Ozkan, Ulla Wollenberger, Frieder Scheller
In order to replace bio-macromolecules by stable synthetic materials in separation techniques and bioanalysis biomimetic receptors and catalysts have been developed: Functional monomers are polymerized together with the target analyte and after template removal cavities are formed in the "molecularly imprinted polymer" (MIP) which resemble the active sites of antibodies and enzymes. Staring almost 80 years ago, around 1,100 papers on MIPs were published in 2016. Electropolymerization allows to deposit MIPs directly on voltammetric electrodes or chips for quartz crystal microbalance (QCM) and surface plasmon resonance (SPR)...
October 5, 2017: Current Medicinal Chemistry
Nicholas C Anderson, Gerard M Carroll, Ryan T Pekarek, Steven T Christensen, Jao van de Lagemaat, Nathan R Neale
We present an impedance technique based on light intensity-modulated high-frequency resistivity (IMHFR) that provides a new way to elucidate both the thermodynamics and kinetics in complex semiconductor photoelectrodes. We apply IMHFR to probe electrode interfacial energetics on oxide-modified semiconductor surfaces frequently used to improve the stability and efficiency of photoelectrochemical water splitting systems. The technique measures the overpotential for HER relative to its thermodynamic potential in Si photocathodes coated with three oxides (SiOx, TiO2, and Al2O3) and a Pt catalyst...
October 5, 2017: Journal of Physical Chemistry Letters
Gloria Alvarez-Sola, Iker Uriarte, Maria U Latasa, Maddalen Jimenez, Marina Barcena-Varela, Eva Santamaría, Raquel Urtasun, Carlos Rodriguez-Ortigosa, Jesús Prieto, Fernando J Corrales, Anna Baulies, Carmen García-Ruiz, Jose C Fernandez-Checa, Pedro Berraondo, Maite G Fernandez-Barrena, Carmen Berasain, Matías A Avila
The liver displays a remarkable regenerative capacity triggered upon tissue injury or resection. However, liver regeneration can be overwhelmed by excessive parenchymal destruction or diminished by pre-existing conditions hampering repair. Fibroblast growth factor 19 (FGF19, rodent FGF15) is an enterokine that regulates liver bile acid and lipid metabolism, and stimulates hepatocellular protein synthesis and proliferation. FGF19/15 is also important for liver regeneration after partial hepatectomy (PH). Therefore recombinant FGF19 would be an ideal molecule to stimulate liver regeneration, but its applicability may be curtailed by its short half-life...
October 5, 2017: Cell Death & Disease
Neelam Yadav, Anil Kumar Chhillar, Chandra S Pundir
The nanoparticles of hemoglobin (HbNPs) were prepared by desolvation method and characterized by transmission electron microscopy (TEM),UV-visible spectroscopy, Fourier transformation infra red (FTIR) spectroscopy and X-ray diffraction (XRD) and atomic force microscopy (AFM). Protein profile of HbNPs was also studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). An amperometric acrylamide biosensor was constructed by immobilizing covalently HbNPs onto polycrystalline Au electrode...
September 28, 2017: International Journal of Biological Macromolecules
Zhi-Tong Li, Feng Ji, Xin-Wei Han, Li Wang, Yong-Qiang Yue, Zhong-Gao Wang
GOALS: We assessed the relationship between gastroesophageal reflux disease (GERD) and hypertension and whether antiacid therapy could be used to control blood pressure (BP) on hypertension in patients with GERD. BACKGROUND: Gastroesophageal reflux disease (GERD) may provoke cardiovascular disease. Many factors are involved in the development of essential hypertension, but whether GERD has a role needs further study. STUDY: Patients with essential hypertension (n=86) were studied by 24-hour continuous BP monitoring and esophageal impedance and pH monitoring...
September 28, 2017: Journal of Clinical Gastroenterology
Sanju Gupta, Tyler Smith, Alexander Banaszak, John Boeckl
Graphene quantum dots (GQDs), derived from functionalized graphene precursors are graphene sheets a few nanometers in the lateral dimension having a several-layer thickness. They are zero-dimensional materials with quantum confinement and edge site effects. Intense research interest in GQDs is attributed to their unique physicochemical phenomena arising from the sp²-bonded carbon nanocore surrounded with edged plane functional moieties. In this work, GQDs are synthesized by both solvothermal and hydrothermal techniques, with the optimal size of 5 nm determined using high-resolution transmission electron microscopy, with additional UV-Vis absorption and fluorescence spectroscopy, revealing electronic band signatures in the blue-violet region...
September 29, 2017: Nanomaterials
Tayfun Vural, Yesim Tugce Yaman, Serhat Ozturk, Serdar Abaci, Emir Baki Denkbas
In this work, we developed a disposable amperometric sandwich-type immunoassay to detect prostate specific antigen (PSA). A self-assembled peptide nanotube (PNT), gold nanoparticle (AuNP) and polyaniline (PANI) composite (PANI/AuNP-PNT) were used to modify a pencil graphite electrode (PGE). Anti-PSA (Ab1) was immobilized on the modified electrode (PANI/AuNP-PNT/PGE) to capture PSA. Horseradish peroxidase (HRP) labeled anti-PSA (HRP-Ab2) was used as a tracer antibody. The modified electrodes were characterized with scanning electron microscopy (SEM), thermogravimetric analysis (TGA), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS)...
September 21, 2017: Journal of Colloid and Interface Science
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