scholarly journals Fabrication of microstructured binary polymer brush “corrals” with integral pH sensing for studies of proton transport in model membrane systems

2018 ◽  
Vol 9 (8) ◽  
pp. 2238-2251 ◽  
Author(s):  
J. Madsen ◽  
R. E. Ducker ◽  
O. Al Jaf ◽  
M. L. Cartron ◽  
A. M. Alswieleh ◽  
...  
Keyword(s):  
Proton Transport ◽  
Polymer Brush ◽  
Model Membrane ◽  
Ph Sensing ◽  
Membrane Systems ◽  
Ph Indicators ◽  
Binary Polymer

Binary polymer brush microstructures incorporating ratiometric fluorescent pH indicators enablein situstudies of light-activated transmembrane proton transport by proteorhodopsin.

How does Amphotericin B Work?: Studies on Model Membrane Systems

1993 ◽  
Vol 3 (3) ◽  
pp. 377-408 ◽  
Author(s):  
Scott C. Hartsel ◽  
Christopher Hatch ◽  
Woubeshet Ayenew
Keyword(s):  
Amphotericin B ◽  
Model Membrane ◽  
Membrane Systems

Multiple microarrays of non-adherent cells on a single 3D stimuli-responsive binary polymer-brush pattern

2018 ◽  
Vol 6 (29) ◽  
pp. 4792-4798 ◽  
Author(s):  
Jianwen Hou ◽  
Runhai Chen ◽  
Jingchuan Liu ◽  
Haozheng Wang ◽  
Qiang Shi ◽  
...  
Keyword(s):  
Polymer Brush ◽  
Adherent Cells ◽  
Stimuli Responsive ◽  
Con A ◽  
Binary Polymer ◽  
Cell Microarrays ◽  
Single Pattern ◽  
Multiple Cell

A hierarchically binary PGAMA/PNIPAM pattern is fabricated, and multiple cell microarrays are formed on this single pattern with the aid of Con A and temperature.

A primary cation transport by a V-type ATPase of low specificity

1996 ◽  
Vol 199 (6) ◽  
pp. 1327-1334 ◽  
Author(s):  
J Küppers ◽  
I Bunse
Keyword(s):  
Ion Transport ◽  
Proton Transport ◽  
Short Circuit ◽  
Membrane Conductance ◽  
Short Circuit Current ◽  
Potential Difference ◽  
Lepidopteran Larvae ◽  
The Family ◽  
K Transport

The enzyme involved in outward K+ transport in insect epithelia belongs to the family of V-ATPases. Evidence has been reported relating the generation of the K+ gradient to a primary electrogenic proton transport via a distinct electrophoretic nH+/K+ antiport. The subject of this paper is the transport of K+ at a thread hair sensillum of the cockroach in situ. We recorded changes in the voltage and resistance of the ion-transporting membrane and of shifts in pH caused by inhibition of energy metabolism and by putative inhibitors of a proton/cation exchanger. The results are supplemented by previous determinations of the K+ activities in the same preparation. 1. In cockroach hair sensilla, the ion transport generates a membrane voltage of 105 mV. We found that the transport rendered the positive output compartment alkaline with respect to the cytoplasm by 1.0 pH unit compared with the pH at equilibrium distribution, and we infer that proton transport cannot be the process that energizes the generation of the K+ gradient. 2. The ion transport created an electrochemical potential difference for protons, DeltaetaH, of approximately 4.5 kJ mol-1, while the potential difference for K+, DeltaetaK, amounted to approximately 11 kJ mol-1. Both potential differences are directed to the cytosol. It follows from DeltaetaK/DeltaetaH that an antiport would have to be electrophoretic to drive K+ by DeltaetaH and it should, therefore, contribute to the membrane conductance. Amiloride and harmaline did not significantly change the pH in the adjacent spaces and did not affect the voltage or the resistance of the transporting membrane. Previous determinations of the impedance have shown that the ATP-independent conductance of this membrane is small, supporting the conclusion that it lacks an electrophoretic antiport. From these results, we deduce that K+ transport in cockroach sensilla is not secondary to a proton transport and an electrochemical proton gradient. The phenomena observed match the performance of a primary, electrogenic, cation-translocating ATPase of the type deduced from analyses of the short-circuit current at the midgut epithelium of lepidopteran larvae. The validity of the H+ transport/antiport hypothesis is discussed.

scholarly journals Iron Mediated Interaction of Alpha Synuclein with Lipid Rafts in Model Membrane Systems

2018 ◽  
Vol 114 (3) ◽  
pp. 244a
Author(s):  
Loredana Casalis ◽  
Fabio Perissinotto ◽  
Denis Scaini
Keyword(s):  
Lipid Rafts ◽  
Alpha Synuclein ◽  
Model Membrane ◽  
Membrane Systems

scholarly journals Reducing the Impacts of Biofouling in RO Membrane Systems through In Situ Low Fluence Irradiation Employing UVC-LEDs

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 415
Author(s):  
Philipp Sperle ◽  
Christian Wurzbacher ◽  
Jörg E. Drewes ◽  
Bertram Skibinski
Keyword(s):  
Hydraulic Resistance ◽  
Extracellular Polymeric Substances ◽  
Residual Effect ◽  
Feed Stream ◽  
Membrane Systems ◽  
Light Emitting ◽  
Cycle Arrest ◽  
Uv Led ◽  
Biofouling Control

Biofouling is a major concern for numerous reverse osmosis membrane systems. UV pretreatment of the feed stream showed promising results but is still not an established technology as it does not maintain a residual effect. By conducting accelerated biofouling experiments in this study, it was investigated whether low fluence UV in situ treatment of the feed using UVC light-emitting diodes (UVC-LEDs) has a lasting effect on the biofilm. The application of UVC-LEDs for biofouling control is a novel hybrid technology that has not been investigated, yet. It could be shown that a low fluence of 2 mJ∙cm−2 delays biofilm formation by more than 15% in lab-scale experiments. In addition, biofilms at the same feed channel pressure drop exhibited a more than 40% reduced hydraulic resistance. The delay is probably linked to the inactivation of cells in the feed stream, modified adsorption properties or an induced cell cycle arrest. The altered hydraulic resistance might be caused by a change in the microbial community, as well as reduced adenosine triphosphate levels per cells, possibly impacting quorum sensing and extracellular polymeric substances production. Due to the observed biofilm attributes, low fluence UV-LED in situ treatment of the feed stream seems to be a promising technology for biofouling control.

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