Acetic Acid Release from Polymeric Membrane pH Electrodes for Generating Local pH Gradients at Ion-Selective Membranes

1999 ◽  
Vol 1 (4) ◽  
pp. 194 ◽  
Author(s):  
Smita Jadhav
Keyword(s):  
Acetic Acid ◽  
Polymeric Membrane ◽  
Ph Gradients ◽  
Acid Release ◽  
Ph Electrodes ◽  
Local Ph ◽  
Selective Membranes

pH Measurement Problems Affecting Assay of Carcinoembryonic Antigen

1975 ◽  
Vol 21 (2) ◽  
pp. 255-257 ◽  
Author(s):  
Jack H Ladenson ◽  
C Elliott Bell
Keyword(s):  
Acetic Acid ◽  
Carcinoembryonic Antigen ◽  
Ammonium Acetate ◽  
Electrode System ◽  
Acid Buffer ◽  
Ph Values ◽  
Blood Ph ◽  
Acetic Acid Buffer ◽  
Ph Electrodes ◽  
Commercial Kit

Abstract Measurement with combination pH electrodes of the pH of the dilute buffers used in a commercial kit (CEA-Roche) for assay of carcinoembryonic antigen resulted in pH values 0.1 to 0.3 unit lower than pH values measured on an electrode system with a capillary junction. If the pH values of these buffers were adjusted, based on such measurements, an error in the assay of 0.2 to 0.6 ng/ml in the 1.5-3.0 ng/ml range would result. We recommend that the pH of dialyzed samples and of the working ethylenediaminetetraacetate and ammonium acetate-acetic acid buffers be monitored with pH electrodes that have a capillary junction between sample and saturated KCl, as is true of most blood-pH instruments. We also recommend use of a 1 mol/liter rather than 2.5 mol/liter stock ammonium acetate-acetic acid buffer, because of the closer similarity of the pH of buffers at this molarity to those at 0.01 mol/liter.

Gabapentin Markedly Reduces Acetic Acid–induced Visceral Nociception

2003 ◽  
Vol 98 (3) ◽  
pp. 729-733 ◽  
Author(s):  
Yi Feng ◽  
Minglei Cui ◽  
William D. Willis
Keyword(s):  
Amino Acids ◽  
Spinal Cord ◽  
Acetic Acid ◽  
Amino Acid ◽  
Intraperitoneal Injection ◽  
Visceral Pain ◽  
Antinociceptive Effect ◽  
Intraperitoneal Administration ◽  
Amino Acid Release ◽  
Acid Release

Background Gabapentin has recently been used clinically as an antihyperalgesic agent to treat certain neuropathic pain states. The aim of this study is to test whether gabapentin is able to inhibit responses to peritoneal irritation-induced visceral pain and to examine the effect of gabapentin on spinal cord amino acid release. Methods The acetic acid-induced writhing assay was used in rats to determine the degree of antinociception. The rats received an intraperitoneal injection of acetic acid 40 min after intraperitoneal administration of vehicle or gabapentin (50, 100, or 200 mg/kg). Cerebrospinal fluid dialysate was collected by microdialysis from the spinal subarachnoid space in anesthetized rats. Acetic acid-induced release of amino acids into the dialysate, including glutamate, aspartate, serine, glutamine, and glycine, following intraperitoneal injection of acetic acid was evaluated by measurements of changes in the concentrations of these amino acids. The effects of pretreatment with saline or gabapentin (100 mg/kg intraperitoneal) on amino acid release were compared. Results Gabapentin reduced writhing responses in a dose-related fashion. Dialysate concentrations of glutamate, aspartate, and serine increased significantly following intraperitoneal injection of acetic acid, while glutamine and glycine concentrations were not increased significantly. When compared to saline-treated rats, animals pretreated with 100 mg/kg gabapentin showed suppression of the acetic acid-induced increases in glutamate, aspartate, and serine concentrations. Conclusions These data demonstrate that gabapentin effectively inhibits acetic acid-induced nociception, and the antinociceptive effect of gabapentin correlates with the suppression of noxious-evoked release of excitatory amino acids in the spinal cord.

Tuning the Photoluminescence of DNA-Wrapped Carbon Nanotubes by pH

2019 ◽  
Author(s):  
Niyousha Mohammadshafie
Keyword(s):  
Carbon Nanotubes ◽  
Living Cells ◽  
Microfluidic Channels ◽  
Ph Gradients ◽  
Local Ph ◽  
Dna Wrapping

These findings contribute in several ways to our understanding of DNA wrapping structure on the encased SWCNT and provide a basis for design of nanotube-based sensors for detecting local pH gradients in restricted environments, such as in living cells and microfluidic channels.

Microaligned collagen matrices by hydrodynamic focusing: controlling the pH-induced self-assembly

2005 ◽  
Vol 898 ◽  
Author(s):  
Sarah Köester ◽  
Jennie B Leach ◽  
Thomas Pfohl ◽  
Joyce Y Wong
Keyword(s):  
Self Assembly ◽  
Type I Collagen ◽  
Polarized Light ◽  
Type I ◽  
Hydrodynamic Focusing ◽  
Microfluidic Mixing ◽  
Ph Gradients ◽  
The Hierarchical Structure ◽  
Local Ph

AbstractThe hierarchical structure of type I collagen fibrils is a key contributor to the mechanical properties of the extracellular matrix (ECM). It is known that the process of in vitro fibrillogenesis strongly depends on the pH of the collagen solution. To date, there are few methods available for precisely controlling and investigating the dependence of collagen fibril assembly on the local pH. The objective of this work was to create highly defined pH gradients to systematically determine the effects of local pH on microscale collagen fibrillogenesis and alignment. We use a microfluidic mixing device to create a diffusion controlled pH gradient, which in turn initiates the self-assembly and concurrent flow-alignment of soluble collagen. Finite element method simulations of the hydrodynamic and diffusive phenomena are used to calculate the local concentrations of the components involved in the reaction. We develop a model to analytically calculate the local pH in the microfluidic device from these concentrations. A comparison with the experimental results from polarized light microscopy are in good agreement with the simulations.

Tuning the Photoluminescence of DNA-Wrapped Carbon Nanotubes by pH

2019 ◽  
Author(s):  
Niyousha Mohammadshafie
Keyword(s):  
Carbon Nanotubes ◽  
Living Cells ◽  
Microfluidic Channels ◽  
Ph Gradients ◽  
Local Ph ◽  
Dna Wrapping

These findings contribute in several ways to our understanding of DNA wrapping structure on the encased SWCNT and provide a basis for design of nanotube-based sensors for detecting local pH gradients in restricted environments, such as in living cells and microfluidic channels.

Segregative Clustering of Lo and Ld Membrane Microdomains Induced by Local pH Gradients in GM1-Containing Giant Vesicles: A Lipid Model for Cellular Polarization

Langmuir ◽  
2012 ◽  
Vol 28 (47) ◽  
pp. 16327-16337 ◽  
Author(s):  
Galya Staneva ◽  
Nicolas Puff ◽  
Michel Seigneuret ◽  
Hélène Conjeaud ◽  
Miglena I. Angelova
Keyword(s):  
Membrane Microdomains ◽  
Giant Vesicles ◽  
Ph Gradients ◽  
Cellular Polarization ◽  
Local Ph

scholarly journals Light-Addressable Actuator-Sensor Platform for Monitoring and Manipulation of pH Gradients in Microfluidics: A Case Study with the Enzyme Penicillinase

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 171
Author(s):  
Rene Welden ◽  
Melanie Jablonski ◽  
Christina Wege ◽  
Michael Keusgen ◽  
Patrick Hermann Wagner ◽  
...  
Keyword(s):  
Reaction Rate ◽  
Enzymatic Reaction ◽  
Microfluidic Channel ◽  
Ph Gradients ◽  
Ph Influence ◽  
Sensor Platform ◽  
Local Ph ◽  
Scanning Electron ◽  
Light Addressable Potentiometric Sensor

The feasibility of light-addressed detection and manipulation of pH gradients inside an electrochemical microfluidic cell was studied. Local pH changes, induced by a light-addressable electrode (LAE), were detected using a light-addressable potentiometric sensor (LAPS) with different measurement modes representing an actuator-sensor system. Biosensor functionality was examined depending on locally induced pH gradients with the help of the model enzyme penicillinase, which had been immobilized in the microfluidic channel. The surface morphology of the LAE and enzyme-functionalized LAPS was studied by scanning electron microscopy. Furthermore, the penicillin sensitivity of the LAPS inside the microfluidic channel was determined with regard to the analyte’s pH influence on the enzymatic reaction rate. In a final experiment, the LAE-controlled pH inhibition of the enzyme activity was monitored by the LAPS.

EVALUATION OF DIFFERENT POLYMERIC MEMBRANE SUPPORT FOR ACETIC ACID REMOVAL BY SUPPORTED LIQUID MEMBRANE PROCESS

2016 ◽  
Vol 78 (12) ◽  
Author(s):  
Norlisa Harruddin ◽  
Syed M. Saufi ◽  
Che Ku M. Faizal ◽  
Abdul Wahab Mohammad
Keyword(s):  
Acetic Acid ◽  
Fermentation Process ◽  
Liquid Membrane ◽  
Porous Membrane ◽  
Supported Liquid Membrane ◽  
Polymeric Membrane ◽  
Membrane Process ◽  
Pvdf Membrane ◽  
Membrane Morphology ◽  
Biomass Resources

In this study, the removal of acetic acid from aqueous solution through supported liquid membrane (SLM) process by using tri-n-octylamine (TOA) as a carrier and sodium hydroxide as a stripping agent was conducted. Acetic acid can inhibit the microbial activity during fermentation process of biomass hydrolysate, thus decreasing the bioethanol production. It is crucial to remove acetic acid prior to fermentation process in order to increase the yield of bioethanol from biomass resources. In this study, the removal of acetic acid was conducted using different types of polymeric membrane in supported liquid membrane process. Three types of polymeric membranes support which are polyethersulfone (PES), polysulfone (PSF) and polyvinyflouride (PVDF) prepared by vapour induced phase separation (VIPS) were used as a support material. The types of polymer give a significant effect on membrane morphology and its physical characteristics. PES exhibited a porous membrane support with a symmetric structure and high contact angle. Almost 86% of 10 g/l of acetic acid was successfully removed by using PES as a support membrane, compared to the 6% and 38% removal using PSF and PVDF membrane, respectively.

Sign in / Sign up

Export Citation Format

Share Document