journal
MENU ▼
Read by QxMD icon Read
search

Membranes

journal
https://www.readbyqxmd.com/read/28294967/single-lipid-molecule-dynamics-on-supported-lipid-bilayers-with-membrane-curvature
#1
Philip P Cheney, Alan W Weisgerber, Alec M Feuerbach, Michelle K Knowles
The plasma membrane is a highly compartmentalized, dynamic material and this organization is essential for a wide variety of cellular processes. Nanoscale domains allow proteins to organize for cell signaling, endo- and exocytosis, and other essential processes. Even in the absence of proteins, lipids have the ability to organize into domains as a result of a variety of chemical and physical interactions. One feature of membranes that affects lipid domain formation is membrane curvature. To directly test the role of curvature in lipid sorting, we measured the accumulation of two similar lipids, 1,2-Dihexadecanoyl-sn-glycero-3-phosphoethanolamine (DHPE) and hexadecanoic acid (HDA), using a supported lipid bilayer that was assembled over a nanopatterned surface to obtain regions of membrane curvature...
March 15, 2017: Membranes
https://www.readbyqxmd.com/read/28272296/performance-of-carbon-nanotube-polysulfone-cnt-psf-composite-membranes-during-oil-water-mixture-separation-effect-of-cnt-dispersion-method
#2
Michael Olawale Daramola, Palesa Hlanyane, Oluwafolakemi O Sadare, Olugbenga O Oluwasina, Sunny E Iyuke
Effect of the dispersion method employed during the synthesis of carbon nanotube (CNT)/polysulfone-infused composite membranes on the quality and separation performance of the membranes during oil-water mixture separation is demonstrated. Carbon nanotube/polysulfone composite membranes containing 5% CNT and pure polysulfone membrane (with 0% CNT) were synthesized using phase inversion. Three CNT dispersion methods referred to as Method 1 (M1), Method 2 (M2), and Method 3 (M3) were used to disperse the CNTs...
March 6, 2017: Membranes
https://www.readbyqxmd.com/read/28273869/membranes-with-surface-enhanced-antifouling-properties-for-water-purification
#3
REVIEW
Nima Shahkaramipour, Thien N Tran, Sankara Ramanan, Haiqing Lin
Membrane technology has emerged as an attractive approach for water purification, while mitigation of fouling is key to lower membrane operating costs. This article reviews various materials with antifouling properties that can be coated or grafted onto the membrane surface to improve the antifouling properties of the membranes and thus, retain high water permeance. These materials can be separated into three categories, hydrophilic materials, such as poly(ethylene glycol), polydopamine and zwitterions, hydrophobic materials, such as fluoropolymers, and amphiphilic materials...
March 5, 2017: Membranes
https://www.readbyqxmd.com/read/28264453/assessment-of-a-new-silicon-carbide-tubular-honeycomb-membrane-for-treatment-of-olive-mill-wastewaters
#4
Maria C Fraga, Sandra Sanches, João G Crespo, Vanessa J Pereira
Extremely high removals of total suspended solids and oil and grease were obtained when olive mill wastewaters were filtered using new silicon carbide tubular membranes. These new membranes were used at constant permeate flux to treat real olive mill wastewaters at pilot scale. The filtration conditions were evaluated and optimized in terms of the selection of the permeate flux and flux maintenance strategies employed-backpulsing and backwashing-in order to reduce fouling formation. The results obtained reveal that the combination of backpulses and backwashes helps to maintain the permeate flux, avoids transmembrane pressure increase and decreases the cake resistance...
February 27, 2017: Membranes
https://www.readbyqxmd.com/read/28241433/fogging-control-on-ldpe-eva-coextruded-films-wettability-behavior-and-its-correlation-with-electric-performance
#5
Miguel A Waldo-Mendoza, Zoe V Quiñones-Jurado, Juan C Pérez-Medina, Bernardo Yañez-Soto, Pedro E Ramírez-González
The transformation of fog at a non-visible water layer on a membrane of low-density polyethylene (LDPE) and ethylene-vinyl acetate (EVA) was evaluated. Nonionic surfactants of major demand in the polyolefin industry were studied. A kinetic study using a hot fog chamber showed that condensation is controlled by both the diffusion and permanency of the surfactant more than by the change of the surface energy developed by the wetting agents. The greatest permanency of the anti-fog effect of the LDPE/EVA surface was close to 3000 h...
February 22, 2017: Membranes
https://www.readbyqxmd.com/read/28218648/expression-purification-and-monitoring-of-conformational-changes-of-hcb2-tmh67h8-in-different-membrane-mimetic-lipid-mixtures-using-circular-dichroism-and-nmr-techniques
#6
Elvis K Tiburu, Jianqin Zhuang, Heidimarie N A Fleischer, Patrick K Arthur, Gordon A Awandare
This work was intended to develop self-assembly lipids for incorporating G-protein coupled receptors (GPCRs) in order to improve the success rate for nuclear magnetic resonance spectroscopy (NMR) structural elucidation. We hereby report the expression and purification of uniformly (15)N-labeled human cannabinoid receptor-2 domain in insect cell media. The domain was refolded by screening several membrane mimetic environments. Different q ratios of isotropic bicelles were screened for solubilizing transmembrane helix 6, 7 and 8 (TMH67H8)...
February 17, 2017: Membranes
https://www.readbyqxmd.com/read/28218644/review-of-membranes-for-helium-separation-and-purification
#7
REVIEW
Colin A Scholes, Ujjal K Ghosh
Membrane gas separation has potential for the recovery and purification of helium, because the majority of membranes have selectivity for helium. This review reports on the current state of the research and patent literature for membranes undertaking helium separation. This includes direct recovery from natural gas, as an ancillary stage in natural gas processing, as well as niche applications where helium recycling has potential. A review of the available polymeric and inorganic membranes for helium separation is provided...
February 17, 2017: Membranes
https://www.readbyqxmd.com/read/28208685/hollow-fiber-supported-liquid-membrane-extraction-combined-with-hplc-uv-for-simultaneous-preconcentration-and-determination-of-urinary-hippuric-acid-and-mandelic-acid
#8
Abdulrahman Bahrami, Farhad Ghamari, Yadollah Yamini, Farshid Ghorbani Shahna, Abbas Moghimbeigi
This work describes a new extraction method with hollow-fiber liquid-phase microextraction based on facilitated pH gradient transport for analyzing hippuric acid and mandelic acid in aqueous samples. The factors affecting the metabolites extraction were optimized as follows: the volume of sample solution was 10 mL with pH 2 containing 0.5 mol·L(-1) sodium chloride, liquid membrane containing 1-octanol with 20% (w/v) tributyl phosphate as the carrier, the time of extraction was 150 min, and stirring rate was 500 rpm...
February 12, 2017: Membranes
https://www.readbyqxmd.com/read/28208658/synthesis-and-transport-properties-of-novel-mof-pim-1-mof-sandwich-membranes-for-gas-separation
#9
Alessio Fuoco, Muhanned R Khdhayyer, Martin P Attfield, Elisa Esposito, Johannes C Jansen, Peter M Budd
Metal-organic frameworks (MOFs) were supported on polymer membrane substrates for the fabrication of composite polymer membranes based on unmodified and modified polymer of intrinsic microporosity (PIM-1). Layers of two different MOFs, zeolitic imidazolate framework-8 (ZIF-8) and Copper benzene tricarboxylate ((HKUST-1), were grown onto neat PIM-1, amide surface-modified PIM-1 and hexamethylenediamine (HMDA) -modified PIM-1. The surface-grown crystalline MOFs were characterized by a combination of several techniques, including powder X-ray diffraction, infrared spectroscopy and scanning electron microscopy to investigate the film morphology on the neat and modified PIM-1 membranes...
February 11, 2017: Membranes
https://www.readbyqxmd.com/read/28208740/recursive-alterations-of-the-relationship-between-simple-membrane-geometry-and-insertion-of-amphiphilic-motifs
#10
REVIEW
Kenneth Lindegaard Madsen, Rasmus Herlo
The shape and composition of a membrane directly regulate the localization, activity, and signaling properties of membrane associated proteins. Proteins that both sense and generate membrane curvature, e.g., through amphiphilic insertion motifs, potentially engage in recursive binding dynamics, where the recruitment of the protein itself changes the properties of the membrane substrate. Simple geometric models of membrane curvature interactions already provide prediction tools for experimental observations, however these models are treating curvature sensing and generation as separated phenomena...
February 8, 2017: Membranes
https://www.readbyqxmd.com/read/28125062/effect-of-sodium-and-chloride-binding-on-a-lecithin-bilayer-a-molecular-dynamics-study
#11
Maria M Reif, Christopher Kallies, Volker Knecht
The effect of ion binding on the structural, mechanical, dynamic and electrostatic properties of a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer in a 0.5 M aqueous NaCl solution is investigated using classical atomistic molecular dynamics simulation with different force-field descriptions for ion-ion and ion-lipid interactions. Most importantly, the repulsive Lennard-Jones parameters for the latter were modified, such that approximately similar binding of cations and anions to the lipid membrane is achieved...
January 25, 2017: Membranes
https://www.readbyqxmd.com/read/28106775/colloidal-fouling-of-nanofiltration-membranes-development-of-a-standard-operating-procedure
#12
Md Abdullaha Al Mamun, Subir Bhattacharjee, David Pernitsky, Mohtada Sadrzadeh
Fouling of nanofiltration (NF) membranes is the most significant obstacle to the development of a sustainable and energy-efficient NF process. Colloidal fouling and performance decline in NF processes is complex due to the combination of cake formation and salt concentration polarization effects, which are influenced by the properties of the colloids and the membrane, the operating conditions of the test, and the solution chemistry. Although numerous studies have been conducted to investigate the influence of these parameters on the performance of the NF process, the importance of membrane preconditioning (e...
January 18, 2017: Membranes
https://www.readbyqxmd.com/read/28106711/biological-fuel-cells-and-membranes
#13
REVIEW
Zahra Ghassemi, Gymama Slaughter
Biofuel cells have been widely used to generate bioelectricity. Early biofuel cells employ a semi-permeable membrane to separate the anodic and cathodic compartments. The impact of different membrane materials and compositions has also been explored. Some membrane materials are employed strictly as membrane separators, while some have gained significant attention in the immobilization of enzymes or microorganisms within or behind the membrane at the electrode surface. The membrane material affects the transfer rate of the chemical species (e...
January 17, 2017: Membranes
https://www.readbyqxmd.com/read/28036043/concentration-of-tea-extracts-by-osmotic-evaporation-optimisation-of-process-parameters-and-effect-on-antioxidant-activity
#14
Marisa P Marques, Vítor D Alves, Isabel M Coelhoso
In this work, the concentration process of three different tea extracts (medicinal Rosil No. 6, Black, and Forest Fruit teas) using the osmotic evaporation (OE) process, was studied. The effect of the OE process on the content of phenolic compounds and antioxidant activity was evaluated. The concentration process was carried out in a hollow-fibre membrane contactor with an effective surface area of 0.54 m². The tea extract was circulated through the shell side of the contactor, while a concentrated osmotic solution (CaCl₂ 5 M) was circulated inside the fibres...
December 28, 2016: Membranes
https://www.readbyqxmd.com/read/27999394/nanofiber-ion-exchange-membranes-for-the-rapid-uptake-and-recovery-of-heavy-metals-from-water
#15
Nithinart Chitpong, Scott M Husson
An evaluation of the performance of polyelectrolyte-modified nanofiber membranes was undertaken to determine their efficacy in the rapid uptake and recovery of heavy metals from impaired waters. The membranes were prepared by grafting poly(acrylic acid) (PAA) and poly(itaconic acid) (PIA) to cellulose nanofiber mats. Performance measurements quantified the dynamic ion-exchange capacity for cadmium (Cd), productivity, and recovery of Cd(II) from the membranes by regeneration. The dynamic binding capacities of Cd(II) on both types of nanofiber membrane were independent of the linear flow velocity, with a residence time of as low as 2 s...
December 20, 2016: Membranes
https://www.readbyqxmd.com/read/27999368/structure-and-nanomechanics-of-model-membranes-by-atomic-force-microscopy-and-spectroscopy-insights-into-the-role-of-cholesterol-and-sphingolipids
#16
REVIEW
Berta Gumí-Audenis, Luca Costa, Francesco Carlá, Fabio Comin, Fausto Sanz, Marina I Giannotti
Biological membranes mediate several biological processes that are directly associated with their physical properties but sometimes difficult to evaluate. Supported lipid bilayers (SLBs) are model systems widely used to characterize the structure of biological membranes. Cholesterol (Chol) plays an essential role in the modulation of membrane physical properties. It directly influences the order and mechanical stability of the lipid bilayers, and it is known to laterally segregate in rafts in the outer leaflet of the membrane together with sphingolipids (SLs)...
December 19, 2016: Membranes
https://www.readbyqxmd.com/read/27999364/incorporation-of-graphene-related-carbon-nanosheets-in-membrane-fabrication-for-water-treatment-a-review
#17
REVIEW
Jenny Lawler
The minimization of the trade-off between the flux and the selectivity of membranes is a key area that researchers are continually working to optimise, particularly in the area of fabrication of novel membranes. Flux versus selectivity issues apply in many industrial applications of membranes, for example the unwanted diffusion of methanol in fuel cells, retention of valuable proteins in downstream processing of biopharmaceuticals, rejection of organic matter and micro-organisms in water treatment, or salt permeation in desalination...
December 19, 2016: Membranes
https://www.readbyqxmd.com/read/27983631/vitamin-e-circular-dichroism-studies-insights-into-conformational-changes-induced-by-the-solvent-s-polarity
#18
Drew Marquardt, Brad J Van Oosten, Mikel Ghelfi, Jeffrey Atkinson, Thad A Harroun
We used circular dichroism (CD) to study differences in CD spectra between α-, δ-, and methylated-α-tocopherol in solvents with different polarities. CD spectra of the different tocopherol structures differ from each other in intensity and peak locations, which can be attributed to chromanol substitution and the ability to form hydrogen bonds. In addition, each structure was examined in different polarity solvents using the Reichardt index-a measure of the solvent's ionizing ability, and a direct measurement of solvent-solute interactions...
December 14, 2016: Membranes
https://www.readbyqxmd.com/read/27983630/application-of-semipermeable-membranes-in-glucose-biosensing
#19
REVIEW
Tanmay Kulkarni, Gymama Slaughter
Glucose biosensors have received significant attention in recent years due to the escalating mortality rate of diabetes mellitus. Although there is currently no cure for diabetes mellitus, individuals living with diabetes can lead a normal life by maintaining tight control of their blood glucose levels using glucose biosensors (e.g., glucometers). Current research in the field is focused on the optimization and improvement in the performance of glucose biosensors by employing a variety of glucose selective enzymes, mediators and semipermeable membranes to improve the electron transfer between the active center of the enzyme and the electrode substrate...
December 14, 2016: Membranes
https://www.readbyqxmd.com/read/27983583/treated-seawater-as-a-magnesium-source-for-phosphorous-recovery-from-wastewater-a-feasibility-and-cost-analysis
#20
Cejna Anna Quist-Jensen, Mads Koustrup Jørgensen, Morten Lykkegaard Christensen
Conventional resources of phosphorous are at high risk of depletion in the near future due to current practices of its exploitation, thus new and improved exploration methodologies need to be developed to ensure phosphorous security. Today, some treatment plants recover phosphorous from municipal wastewater as struvite (MgNH₄PO₄·6H₂O). Magnesium is often added to the wastewater as MgCl₂·6H₂O to facilitate the phosphorous recovery. However, the use of magnesium increases the costs of the process and is not aligned with sustainable development, therefore, alternative magnesium sources have to be found...
December 13, 2016: Membranes
journal
journal
43930
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"