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https://www.readbyqxmd.com/read/29447970/development-of-a-new-paper-based-nano-biosensor-based-on-the-co-catalytic-effect-of-tyrosinase-from-banana-peel-tissue-musa-cavendish-and-functionalized-silica-nanoparticles-for-voltammetric-determination-of-l-tyrosine
#1
Mohadeseh Rahimi-Mohseni, Jahan Bakhsh Raoof, Reza Ojani, Tahereh A Aghajanzadeh, Ayemeh Bagheri Hashkavayi
A new and facile method for electrochemical determination of L-tyrosine was designed. Tyrosinase from banana peel tissue was immobilized at fiber matrices of the paper disc via physical adsorption. The mediator potassium hexacyanoferrate and 3-mercaptopropyl trimethoxysilane-functionalized silica nanoparticles were added to the paper disc, respectively. The modified paper disc was placed on the top of the graphite screen printed electrode and electrochemical characterization of this biosensor was studied by cyclic voltammetry and electrochemical impedance spectroscopy methods...
February 12, 2018: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/29447045/a-four-channel-electrical-impedance-spectroscopy-module-for-cortisol-biosensing-in-sweat-based-wearable-applications
#2
Devangsingh Sankhala, Sriram Muthukumar, Shalini Prasad
A four-channel electrochemical impedance spectroscopy (EIS) analyzer module has been demonstrated on flexible chemi-impedance sensors fabricated with gold electrodes for wearable applications. The module can perform time division multiplexed (TDM) impedance measurements on four sensors at 1 kHz. In this work, we characterize the system for the detection of cortisol in an ultralow volume (1-3 µL) of perspired human sweat, sensor performance, and effects during continuous cortisol dosing and with pH and temperature variations expected on the surface of the skin that would be representative of use conditions as seen by a wearable device...
February 1, 2018: SLAS Technology
https://www.readbyqxmd.com/read/29437910/modern-diagnosis-of-gerd-the-lyon-consensus
#3
REVIEW
C Prakash Gyawali, Peter J Kahrilas, Edoardo Savarino, Frank Zerbib, Francois Mion, André J P M Smout, Michael Vaezi, Daniel Sifrim, Mark R Fox, Marcelo F Vela, Radu Tutuian, Jan Tack, Albert J Bredenoord, John Pandolfino, Sabine Roman
Clinical history, questionnaire data and response to antisecretory therapy are insufficient to make a conclusive diagnosis of GERD in isolation, but are of value in determining need for further investigation. Conclusive evidence for reflux on oesophageal testing include advanced grade erosive oesophagitis (LA grades C and D), long-segment Barrett's mucosa or peptic strictures on endoscopy or distal oesophageal acid exposure time (AET) >6% on ambulatory pH or pH-impedance monitoring. A normal endoscopy does not exclude GERD, but provides supportive evidence refuting GERD in conjunction with distal AET <4% and <40 reflux episodes on pH-impedance monitoring off proton pump inhibitors...
February 3, 2018: Gut
https://www.readbyqxmd.com/read/29428946/determination-of-cardiac-output-in-pulmonary-hypertension-using-impedance-cardiography
#4
Marion Dupuis, Elise Noel-Savina, Gregoire Prévot, Laurent Tétu, Fabien Pillard, Daniel Rivière, Alain Didier
BACKGROUND: Cardiac output (CO) is a prognostic factor in pulmonary hypertension (PH). Right heart catheterisation using the direct Fick method or thermodilution (TD) is the reference technique for CO measurement. Impedance cardiography (IPc) is a known non-invasive method of measuring CO. OBJECTIVES: In our study, we assume that the measurement of CO by IPc using the PHYSIOFLOW® system is as accurate as TD or using the direct Fick method in patients with PH in group 1 or group 4...
February 9, 2018: Respiration; International Review of Thoracic Diseases
https://www.readbyqxmd.com/read/29427733/extraesophageal-symptoms-and-diseases-attributed-to-gerd-where-is-the-pendulum-swinging-now
#5
Michael F Vaezi, David Katzka, Frank Zerbib
BACKGROUND AND AIMS: The purpose of this review is to outline the recent developments in the field of extraesophageal reflux disease and provide clinically relevant recommendations. METHODS: The recommendations outlined in this review are based on expert opinion and on relevant publications from PubMed and EMbase. The Clinical Practice Updates Committee of the American Gastroenterological Association proposes the following recommendations: 1. The role of a gastroenterologist in patients referred for evaluation of suspected extra esophageal symptom is to assess for gastroesophageal etiologies that could contribute to the presenting symptoms...
February 7, 2018: Clinical Gastroenterology and Hepatology
https://www.readbyqxmd.com/read/29427278/complexation-of-sulfamethazine-with-cd-ii-and-pb-ii-implication-for-co-adsorption-of-smt-and-cd-ii-on-goethite
#6
Ting Tang, Chen Yang, Li Wang, Xianying Jiang, Zhi Dang, Weilin Huang
This study quantified the complex stability constants of sulfamethazine (SMT) with cadmium (Cd2+) and lead (Pb2+) under different pH conditions. The UV-Vis spectrophotometer was used for acquiring the complexation data. Results showed that the complex stability constants of SMT with cadmium (Cd2+) and lead (Pb2+) increased as a function of the solution pH. In the investigated pH range, Cd2+ showed stronger complex affinity with SMT than Pb2+. It appeared that cation-π interactions might dominate the complex between SMT with Pb2+ and Cd2+ at acid environment, and the covalent bonding might play a major role at neutral environment...
February 9, 2018: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/29414837/purification-and-characterization-of-a-biofilm-degradable-dextranase-from-a-marine-bacterium
#7
Wei Ren, Ruanhong Cai, Wanli Yan, Mingsheng Lyu, Yaowei Fang, Shujun Wang
This study evaluated the ability of a dextranase from a marine bacterium Catenovulum sp. (Cadex) to impede formation of Streptococcus mutans biofilms, a primary pathogen of dental caries, one of the most common human infectious diseases. Cadex was purified 29.6-fold and had a specific activity of 2309 U/mg protein and molecular weight of 75 kDa. Cadex showed maximum activity at pH 8.0 and 40 °C and was stable at temperatures under 30 °C and at pH ranging from 5.0 to 11.0. A metal ion and chemical dependency study showed that Mn2+ and Sr2+ exerted positive effects on Cadex, whereas Cu2+, Fe3+, Zn2+, Cd2+, Ni2+, and Co2+ functioned as inhibitors...
February 7, 2018: Marine Drugs
https://www.readbyqxmd.com/read/29404047/electrochemical-determination-of-an-anti-hyperlipidimic-drug-pitavastatin-at-electrochemical-sensor-based-on-electrochemically-pre-treated-polymer-film-modified-gce
#8
Umar J Pandit, Gowhar A Naikoo, Mehraj Ud Din Sheikh, Gulzar A Khan, K K Raj, S N Limaye
An electrochemically pretreated silver macroporous (Ag MP) multiwalled carbon nanotube modified glassy carbon electrode (PAN-Ag MP-MWCNT-GCE) was fabricated for the selective determination of an anti-hyperlipidimic drug, pitavastatin (PST). The fabricated electrochemical sensor was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The fabricated electrode was employed in quantifying and determining PST through differential pulse adsorptive stripping voltammetry (DPAdSV) and CV...
August 2017: Journal of Pharmaceutical Analysis
https://www.readbyqxmd.com/read/29402081/electrical-impedance-measurements-of-biological-cells-in-response-to-external-stimuli
#9
Amin Mansoorifar, Anil Koklu, Shihong Ma, Ganesh V Raj, Ali Beskok
Dielectric spectroscopy (DS) is a non-invasive technique for real-time measurements of the impedance spectra of biological cells. DS enables characterization of cellular dielectric properties such as membrane capacitance and cytoplasmic conductivity. We have developed a lab-on-a-chip device that uses an electro-activated micro-wells array for capturing, DS measurements, and unloading of biological cells. Impedance measurements were conducted at 0.2 V in 10 kHZ - 40 MHz range with six-seconds time resolution...
February 5, 2018: Analytical Chemistry
https://www.readbyqxmd.com/read/29399800/double-blind-placebo-controlled-study-with-alginate-suspension-for-laryngopharyngeal-reflux-disease
#10
Wen-Hsuan Tseng, Ping-Huei Tseng, Jia-Feng Wu, Ya-Chin Hsu, Ting-Yi Lee, Yen-Hsuan Ni, Hsiu-Po Wang, Tzu-Yu Hsiao, Wei-Chung Hsu
OBJECTIVE: Treatment for laryngopharyngeal reflux disease (LPRD) is challenging because of delays in recognition and poor responsiveness to proton-pump inhibitor therapy. The aim of this study was to determine the efficacy and safety of liquid alginate suspension for treating LPRD. METHODS: A double-blind, placebo-controlled, prospective study comparing 8 weeks of treatment with Alginos Oral Suspension (TTY Biopharm Co. Ltd., Taipei, Taiwan) (sodium alginate 1,000 mg three times daily) with a placebo was conducted on patients who fulfilled the criteria of at least one symptom consistent with LPRD, a total reflux symptom index (RSI) score of > 10, and a total reflux finding score (RFS) of > 5...
February 5, 2018: Laryngoscope
https://www.readbyqxmd.com/read/29393747/practical-approaches-for-overcoming-challenges-in-heightened-characterization-of-antibody-drug-conjugates-with-new-methodologies-and-ultrahigh-resolution-mass-spectrometry
#11
Olga V Friese, Jacquelynn N Smith, Paul W Brown, Jason C Rouse
Antibody-drug conjugation strategies are continuously evolving as researchers work to improve the safety and efficacy of the molecules. However, as a part of process and product development, confirmation of the resulting innovative structures requires new, specialized mass spectrometry (MS) approaches and methods, as compared to those already established for antibody-drug conjugates (ADCs) and the heightened characterization practices used for monoclonal antibodies (mAbs), in order to accurately elucidate the resulting conjugate forms, which can sometimes have labile chemical bonds and more extreme chemical properties like hydrophobic patches...
February 2, 2018: MAbs
https://www.readbyqxmd.com/read/29393167/evaluation-of-esophageal-mucosal-integrity-in-patients-with-gastroesophageal-reflux-disease
#12
Tomoaki Matsumura, Makoto Arai, Hideaki Ishigami, Mai Fujie, Kentaro Ishikawa, Naoki Akizue, Takashi Taida, Yuki Ohta, Shinsaku Hamanaka, Kenichiro Okimoto, Keiko Saito, Daisuke Maruoka, Tomoo Nakagawa, Naoya Kato
BACKGROUND: Impaired esophageal mucosal integrity plays a role in causing symptoms of gastroesophageal reflux disease (GERD). Recently, the assessment of esophageal baseline impedance (BI) using the multichannel intraluminal impedance-pH (MII-pH) test was suggested as a surrogate technique for the study of esophageal mucosal integrity and was reported to be useful in distinguishing GERD from non-GERD. However, measuring BI requires a 24-h testing period, is complicated, and causes considerable patient discomfort...
February 1, 2018: Digestion
https://www.readbyqxmd.com/read/29384872/the-psychological-results-of-438-patients-with-persisting-gerd-symptoms-by-symptom-checklist-90-revised-scl-90-r-questionnaire
#13
Ping Li, Fei Wang, Guo-Zhong Ji, Lin Miao, Sihong You, Xia Chen
Persisting gastroesophageal reflux disease (GERD) symptoms affect mental state and social activities and mental disorders likewise play a crucial role on GERD symptoms. The aim of this study was to analyze the data of Symptom Checklist by 90-Revised (SCL-90-R) questionnaire in patients with persisting GERD symptom and to explore the impact of psychological factors on them.The patients accepted SCL-90-R questionnaire survey, following endoscopy, high-resolution manometry (HRM) and ambulatory impedance-pH monitoring...
February 2018: Medicine (Baltimore)
https://www.readbyqxmd.com/read/29368532/image-enhanced-endoscopy-is-specific-for-the-diagnosis-of-non-erosive-gastroesophageal-reflux-disease
#14
Neil D Parikh, Artur V Viana, Saloni Shah, Loren Laine
OBJECTIVES: We assessed the performance characteristics of image-enhanced endoscopy with i-Scan or narrow band imaging (NBI) in patients with non-erosive gastroesophageal reflux disease (GERD) compared to controls without heartburn. MATERIAL AND METHODS: Image-enhanced endoscopic findings of vascularity at the squamocolumnar junction, distal esophageal micro-erosions, and non-round pit pattern at the squamocolumnar junction were assessed in cases (heartburn not responsive to PPIs, positive results on validated GERD questionnaire, no esophageal erosions, esophageal biopsies with histologic evidence of GERD (basal cell hyperplasia, elongation of papillae and dilation of intercellular spaces all required)) and in controls (no GERD symptoms or esophageal erosions)...
January 25, 2018: Scandinavian Journal of Gastroenterology
https://www.readbyqxmd.com/read/29356788/throat-clearing-frequently-reported-but-is-it-gerd-related
#15
Mustafa Abdul-Hussein, Mohamed Khalaf, Donald Castell
GOALS: To identify the association of throat clearing (TC) with gastroesophageal reflux disease (GERD) during objective reflux monitoring in a large number of patients studied in our esophageal testing laboratory. BACKGROUND: TC is frequently reported and considered to be an atypical symptom of GERD. Atypical GERD symptoms have been widely investigated and empirically treated with proton pump inhibitors. STUDY: We reviewed ambulatory impedance-pH studies of 186 patients referred for evaluation of possible GERD from January 2011 to December 2015 to evaluate the symptom association (SA) of TC with both an abnormal number of reflux episodes and also abnormal esophageal acid exposure (EAE)...
January 19, 2018: Journal of Clinical Gastroenterology
https://www.readbyqxmd.com/read/29339948/update-on-functional-heartburn
#16
Takahisa Yamasaki, Jessica O'Neil, Ronnie Fass
The definition of functional heartburn has been refined over the years. It is currently described, based upon Rome IV criteria, as typical heartburn symptoms in the presence of normal upper endoscopy findings (including normal biopsies), normal esophageal pH testing, and a negative association between symptoms and reflux events. Functional heartburn is very common, affecting women more than men, and with reflux hypersensitivity makes up the majority of heartburn patients who fail twice-daily proton pump inhibitor therapy...
December 2017: Gastroenterology & Hepatology
https://www.readbyqxmd.com/read/29333061/critical-appraisal-of-rome-iv-criteria-hypersensitive-esophagus-does-belong-to-gastroesophageal-reflux-disease-spectrum
#17
REVIEW
Leonardo Frazzoni, Marzio Frazzoni, Nicola de Bortoli, Salvatore Tolone, Irene Martinucci, Lorenzo Fuccio, Vincenzo Savarino, Edoardo Savarino
The Rome IV Committee introduced a major change in the classification of functional gastrointestinal disorders, proposing a more restrictive definition of gastroesophageal reflux disease (GERD). It was suggested that hypersensitive esophagus (HE) may sit more firmly within the functional realm. It was suggested that GERD diagnosis should be based upon abnormal acid exposure time (AET) only, implying no advantage of impedance-pH over pH monitoring. Symptom association probability (SAP), symptom index (SI) and heartburn relief with proton pump inhibitor (PPI) therapy were regarded as unreliable, whereas a lack of response to PPI was considered as evidence of functional heartburn...
January 2018: Annals of Gastroenterology: Quarterly Publication of the Hellenic Society of Gastroenterology
https://www.readbyqxmd.com/read/29330182/fluorescence-recovery-allows-the-implementation-of-a-fluorescence-reporter-gene-platform-applicable-for-the-detection-and-quantification-of-horizontal-gene-transfer-in-anoxic-environments
#18
Rafael Pinilla, Leise Riber, Søren J Sørensen
The study of horizontal gene transfer (HGT) in microbial communities has been revolutionized by significant advances in cultivation-independent methods based on fluorescence reporter gene technologies. Recently, the combination of these novel approaches with flow cytometry has presented itself as one of the most powerful tools to study the spread of mobile genetic elements (MGEs) in the environment. However, the use of fluorescent markers like green fluorescent protein (GFP) and mCherry is limited by environmental constraints that affect the correct maturation of their fluorophores, such as oxygen availability and pH levels...
January 12, 2018: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29328969/poly-3-6-diamino-9-ethylcarbazole-based-molecularly-imprinted-polymer-sensor-for-ultra-sensitive-and-selective-detection-of-17-%C3%AE-estradiol-in-biological-fluids
#19
Weilu Liu, Haifeng Li, Shangmin Yu, Jiaxing Zhang, Weihua Zheng, Liting Niu, Gengen Li
In this work, we reported the synthesis of 3, 6-diamino-9-ethylcarbazole and its application as a new monomer for preparation of molecularly imprinted polymer (MIP) electrochemical sensor. The as prepared MIP sensor exhibited ultrahigh sensitivity and selectivity for the detection of 17-β-estradiol in attomolar levels (1 × 10-18molL-1). The sensor works by detecting the change of the interfacial impedance that is derived from recognition of 17-β-estradiol on the MIP layer. The MIP sensor based on 3, 6-diamino-9-ethylcarbazole monomer revealed better performance than that of unmodified carbazole monomer...
January 4, 2018: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/29310210/a-new-and-simple-method-for-the-simultaneous-determination-of-amoxicillin-and-nimesulide-using-carbon-black-within-a-dihexadecylphosphate-film-as-electrochemical-sensor
#20
Patrícia B Deroco, Romeu C Rocha-Filho, Orlando Fatibello-Filho
The first electroanalytical method for the simultaneous determination of an important antibiotic (amoxicillin - AMX) and an anti-inflammatory drug (nimesulide -NIM), widely used in combination, is here proposed. In this method, a glassy carbon (GC) substrate modified with carbon black (CB) immobilized within a dihexadecylphosphate (DHP) film is used as electrochemical sensor (CB-DHP/GC). The electrochemical activity of this sensor was assessed (comparatively to that of GC) by electrochemical impedance spectroscopy, using the [Fe(CN)6]3-/4- redox couple, when two different active electron transfer regions were clearly characterized...
March 1, 2018: Talanta
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