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Ph Impedance

Yao Huang, Leping Deng, Pengfei Ju, Luyao Huang, Hongchang Qian, Dawei Zhang, Xiaogang Li, Herman A Terryn, Johannes M C Mol
In this study, a new self-healing shape memory polymer (SMP) coating was prepared to protect the aluminum alloy 2024-T3 from corrosion by the incorporation of dual-function microspheres containing polycaprolactone (PCL) and the corrosion inhibitor 8-hydroxyquinoline (8HQ). The self-healing properties of the coatings were investigated via scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) following the application of different healing conditions...
June 21, 2018: ACS Applied Materials & Interfaces
Marin Kovacic, Jozefina Katic, Hrvoje Kusic, Ana Loncaric Bozic, Mirjana Metikos Hukovic
TiO₂-SnS₂ composite semiconducting photocatalysts with different building component ratios were prepared by hydrothermal synthesis (TiO₂-SnS₂-HT) and by immobilization of commercial TiO₂ and SnS₂ particles (TiO₂-SnS₂-COMM). The band gap values, which determine the catalysts’ photoactivity, were examined by diffuse reflectance spectroscopy and Kubelka⁻Munk transformations. The catalysts’ surface properties: specific surface area, charge and adsorption capacitance at the solid⁻solution interface were characterized using BET analysis, potentiometric titration and electrochemical impedance spectroscopy, respectively...
June 19, 2018: Materials
Jeffrey Rohrbough, Hong-Ngan Nguyen, Fred S Lamb
We utilized plasma membrane-localized ClC-3 to investigate relationships between steady-state transport current (ISS ), gating charge (Q) movement, and cytoplasmic alkalization rate. ClC-3 exhibited lower transport efficiency than ClC-5, as reflected by a larger Q/ISS ratio, but an indistinguishable Cl- /H+ coupling ratio. External SCN- reduced H+ transport rate and uncoupled anion/H+ exchange by 80-90%. "Gluext " removal (E224A) eliminated Q and abolished H+ transport. We hypothesized that M531 impedes "water-wire" H+ transfer from the cytoplasm to E224...
June 19, 2018: Journal of Physiology
Shuo Mi, Chunkai Gu, Pengfei Wu, Hongjuan Liu, Xiang Yan, Dongyue Li, Xiang Tang, Xiaorui Duan, Genyu Wang, Jianan Zhang
Butanol fermentation comprises two successive and distinct stages, namely acidogenesis and solventogenesis. The current lack of clarity regarding the underlying metabolic regulation of fermentation impedes improvements in biobutanol production. Here, a proteomics study was performed in the acidogenesis phase, the lowest pH point (transition point), and the solventogenesis phase in the butanol-producing symbiotic system TSH06. Forty-two Clostridium acetobutylicum proteins demonstrated differential expression levels at different stages...
June 18, 2018: Applied Microbiology and Biotechnology
Jieun Kim, Jeongeun Hyun, Sihyung Wang, Chanbin Lee, Youngmi Jung
Healthy livers have a remarkable regenerative capacity for reconstructing functional hepatic parenchyma after 70% partial hepatectomy (PH). Hepatocytes, usually quiescent in normal healthy livers, proliferate to compensate for hepatic loss after PH. However, the mechanism of hepatocyte involvement in liver regeneration remains unclear. Hedgehog (Hh) pathway plays an important role in tissue reconstitution by regulating epithelial-to-mesenchymal transition (EMT) in liver disease. MicroRNA (miRNA) is involved in cell proliferation and differentiation during embryonic development and carcinogenesis...
June 18, 2018: Cell Death & Disease
Jason Abdallah, Nina George, Takahisa Yamasaki, Stephen Ganocy, Ronnie Fass
BACKGROUND & AIMS: As many as 45% of patients with gastroesophageal reflux disease (GERD) still have symptoms after receiving once-daily proton pump inhibitor (PPI) therapy. We aimed to compare reflux characteristics and patterns between responders and non-responders to once-daily PPI therapy using combined impedance-pH monitoring. METHODS: Patients who reported heartburn and/or regurgitation at least twice per week for 3 months while receiving standard-dose PPI therapy were assigned to the PPI failure group (n=16)...
June 15, 2018: Clinical Gastroenterology and Hepatology
Babita Shashni, Yukio Nagasaki
The critical importance of reactive oxygen species (ROS) as oncogene activators and essential secondary messengers in cancer cell survival have been widely reported. Since oxidative stress has been implicated as being pivotal in various cancers, antioxidant therapy seems an apt strategy to abrogate ROS-mediated cellular processes to attenuate cancers. We therefore synthesized ROS scavenging nitroxide radical-containing nanoparticles (RNPs); pH insensitive RNPO and pH sensitive RNPN , to impede the proliferative and metastatic characteristics of the triple negative breast cancer cell line, MDA-MB-231, both in vitro and in vivo...
May 26, 2018: Biomaterials
Lara-Antonia Beer, Helma Tatge, Nicole Reich, Michel Tenspolde, Alexandra Olling, Sebastian Goy, Klemens Rottner, Alexi Kirilov Alekov, Ralf Gerhard
Toxin A and Toxin B (TcdA/TcdB) are large glucosyltransferases produced by Clostridium difficile. TcdB but not TcdA induces reactive oxygen species (ROS)-mediated early cell death when applied at high concentrations. We found that non-glucosylated Rac1 is essential for induction of early cell death since inhibition of Rac1 impedes this effect. Early cell death only occurs when TcdB is rapidly endocytosed. This was shown by generation of chimeras using the trunk of TcdB from a hypervirulent strain. TcdB from hypervirulent strain has been described to translocate from endosomes at higher pH values and thus, meaning faster than reference type TcdB...
June 14, 2018: Cellular Microbiology
Rulin Zhuang, Jinfu Wu, Fang Lin, Lu Han, Xiaoting Liang, Qingshu Meng, Yuyu Jiang, Zhulin Wang, Aixue Yue, Yuying Gu, Huimin Fan, Xiaohui Zhou, Zhongmin Liu
Pulmonary hypertension (PH) due to left heart disease (LHD) is a common condition associated with significant morbidity. It contributes to the elevation of pulmonary vascular resistance and mean pulmonary pressure, eventually leading to heart failure and even mortality. The present study aimed to explore the potential efficacy of late and long‑term treatment with a Rho‑kinase (ROCK) signaling inhibitor, namely fasudil, in a rat model of end‑stage PH‑LHD. The PH‑LHD model was established by supracoronary aortic banding, and the effect of fasudil treatment on the progression of PH‑LHD was monitored...
June 13, 2018: International Journal of Molecular Medicine
Jörg C Frommlet, Daniel Wangpraseurt, Maria L Sousa, Bárbara Guimarães, Mariana Medeiros da Silva, Michael Kühl, João Serôdio
Dinoflagellates in the genus Symbiodinium exhibit a variety of life styles, ranging from mutualistic endosymbioses with animal and protist hosts to free-living life styles. In culture, Symbiodinium spp. and naturally associated bacteria are known to form calcifying biofilms that produce so-called symbiolites, i.e., aragonitic microbialites that incorporate Symbiodinium as endolithic cells. In this study, we investigated (i) how algal growth and the combined physiological activity of these bacterial-algal associations affect the physicochemical macroenvironment in culture and the microenvironment within bacterial-algal biofilms, and (ii) how these interactions induce the formation of symbiolites...
2018: Frontiers in Microbiology
Ines Gockel, Sebastian Murad Rabe, Stefan Niebisch
Background: Indications for benign esophageal surgery and postoperative follow-up need to be highly elaborated with differentiated and structured algorithms, based on objective functional workup in the esophageal laboratory. Functional outcome is of utmost interest and has to be driven by the need for comprehensive but purposeful diagnostic methods. Methods: Preoperative diagnostic workup procedures by the functional laboratory include 24-h pH-monitoring, impedance testing, and high-resolution manometry (HRM) - in addition to upper gastrointestinal endoscopy and barium swallow/timed barium esophagogram...
April 2018: Visceral Medicine
Arne Kandulski, Lukas Moleda, Martina Müller-Schilling
Background: Due to the high prevalence and incidence of patients with gastroesophageal reflux disease (GERD), the diagnostic workup of patients with symptoms of GERD needs to be balanced between empiric antisecretory therapy and further functional assessment including endoscopy and reflux monitoring. Methods: This article is based on a literature review (PubMed, Medline) using the terms 'gastroesophageal reflux disease' or 'GERD' and 'diagnosis', 'therapy', or 'PPI' with special and critical analysis of the current 'Porto' consensus report...
April 2018: Visceral Medicine
H F Wang, F Liu, M Wang, S Y Du, Y L Zhang
Objective: To compare the clinical data, esophageal motility and reflux characteristic in patients with non-erosive reflux disease (NERD) and reflux esophagitis (RE). Methods: A total of 167 patients of NERD were enrolled in the study[60 males, 107 females, mean age(44.1±13.4) years old], and 151 patients of RE were enrolled [74 males, 77 females, mean age(46.5±9.9) years old]. All patients were surveyed by questionnaires to investigate the clinical data. All patients accepted the esophageal highresolution manometry and 24 hours pH+ impedance monitoring to investigate the esophageal motility and reflux characteristic...
May 29, 2018: Zhonghua Yi Xue za Zhi [Chinese medical journal]
Tanbir Ahmad, Amin Ismail, Siti A Ahmad, Khalilah A Khalil, Leo T Kee, Elmutaz A Awad, Kazeem D Adeyemi, Awis Q Sazili
The autolysis of pretreated bovine skin (PBS) (treated with 0.1 M NaOH and 1% HCl), its endogenous proteases, inhibitors and their effects on quality attributes of gelatin were examined. PBS was subjected to different temperatures (20-90 °C) and pH (2-9) and treated with different protease inhibitors. Maximum autolytic activity of PBS was observed at 40 °C and pH 5. Ethylene-bis (oxyethylenenitrilo) tetraacetic acid (EGTA) was the most effective in impeding the degradation of γ-, β- and α- chains of PBS protein indicating that metallocollagenases were the predominant endogenous proteases in bovine skin...
November 1, 2018: Food Chemistry
Ans Pauwels, Charlotte Broers, Tim Vanuytsel, Nicolas Pardon, Silvia Cocca, Sabine Roman, Frank Zerbib, Jan Tack, Ricard Farré
Introduction: Approximately 30% of healthy volunteers (HVs) show dilated intercellular spaces in the esophageal epithelium suggesting a functionally reduced epithelial integrity. We aimed to evaluate the presence of an altered epithelial integrity in HVs and whether physiological acid could explain such a difference. Methods: Biopsies for Ussing chamber experiments were taken between 3 cm and 5 cm proximal to the gastroesophageal junction. Twenty-four-hour impedance-pH (MII-pH) monitoring was performed in the same 15 HVs...
May 2018: United European Gastroenterology Journal
Sergey Morozov, Vasily Isakov, Mariya Konovalova
AIM: To investigate the effect of dietary fiber on symptoms and esophageal function testing parameters in non-erosive gastroesophageal reflux disease (GERD) (NERD) patients. METHODS: Thirty-six NERD patients with low (< 20 g/d) dietary fiber intake were enrolled in the study. They were examined with the use of symptom questionnaire (GERD-Q), high-resolution esophageal manometry, 24-h esophageal pH-impedance examinations, and food frequency questionnaire before and after 10 d of usual diet supplemented by psyllium 5...
June 7, 2018: World Journal of Gastroenterology: WJG
Mark R Fox, Peter J Kahrilas, Sabine Roman, C Prakash Gyawali, S Mark Scott, Satish S Rao, Jutta Keller, Michael Camilleri
Symptoms related to abnormal gastrointestinal motility and function are common. Oropharyngeal and oesophageal dysphagia, heartburn, bloating, abdominal pain and alterations in bowel habits are among the most frequent reasons for seeking medical attention from internists or general practitioners and are also common reasons for referral to gastroenterologists and colorectal surgeons. However, the nonspecific nature of gastrointestinal symptoms, the absence of a definitive diagnosis on routine investigations (such as endoscopy, radiology or blood tests) and the lack of specific treatments make disease management challenging...
June 5, 2018: Nature Reviews. Gastroenterology & Hepatology
Noriyuki Kawami, Shintaro Hoshino, Yoshimasa Hoshikawa, Nana Takenouchi, Mariko Umezawa, Yuriko Hanada, Mitsuru Kaise, Katsuhiko Iwakiri
BACKGROUND: The present study examined the pathogenesis of potassium-competitive acid blocker (P-CAB)-resistant non-erosive reflux disease (NERD). METHODS: Forty-three patients with NERD, who had persistent reflux symptoms despite the administration of P-CAB, were included in this study. After excluding eosinophilic esophagitis and primary esophageal motility disorders, esophageal impedance-pH monitoring was performed. In symptom index (SI)-positive patients, the mechanism of SI-positivity and percent time with intragastric pH > 4 and with esophageal pH < 4 were investigated according to the presence or absence of Helicobacter pylori infection...
June 5, 2018: Digestion
Andrea Cossettini, Luca Selmi
A simplified lumped geometrical and electrical model for the high-frequency impedance spectroscopy (HFIS) response of nanoelectrodes to capsids and full viruses is developed starting from atomistic descriptions, in order to test the theoretical response of a realistic HFIS CMOS biosensor platform to different viruses. Capacitance spectra are computed for plant (cowpea chlorotic mottle virus), animal (rabbit haemorrhagic disease virus), and human (hepatitis A virus) viruses. A few common features of the spectra are highlighted, and the role of virus charge, pH, and ionic strength on the expected signal is discussed...
April 2018: IEEE Transactions on Nanobioscience
Charnete Casimero, Aaron McConville, John-Joe Fearon, Clare L Lawrence, Charlotte M Taylor, Robert B Smith, James Davis
Monitoring pH within microbial reactors has become an important requirement across a host of applications ranging from the production of functional foods (probiotics) to biofuel cell systems. An inexpensive and scalable composite sensor capable of monitoring the pH within the demanding environments posed by microbial reactors has been developed. A custom designed flavin derivative bearing an electropolymerisable phenol monomer was used to create a redox film sensitive to pH but free from the interferences that can impede conventional pH systems...
October 16, 2018: Analytica Chimica Acta
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