200,086 results match your criteria coupling


The strong interfacial coupling effect of Nafion between LaFeO3/electrolyte for efficient photoelectrochemical water reduction.

Nanotechnology 2021 Nov 30. Epub 2021 Nov 30.

Department of Physics, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, CHINA.

Insufficient reduction capability and scanty active substance limit the application of LaFeO3 (LFO) in the field of photoelectrochemical (PEC) water splitting. In this work, a judicious combination of LFO/Nafion composite to improve the PEC performance by a special dip-coating method on the FTO is demonstrated. The photocurrent density of the LFO electrode coated with two layers Nafion increased to -23. Read More

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November 2021

Construction of an enzyme-based all-fiber SPR biosensor for detection of enantiomers.

Biosens Bioelectron 2021 Nov 25;198:113836. Epub 2021 Nov 25.

College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China. Electronic address:

Chiral analysis of amino acids (AAs) is of great importance in medical science due to the distinctive effect of AA isomers on human health. Although various chiral recognition techniques have been developed, the quantitative chiral recognition of low-level AA isomers remains challenging. Here, we combined the fiber optic SPR with an enzyme-substrate recognition mechanism to construct a direct-assay-type chiral AA biosensor. Read More

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November 2021

In-Depth Studies of Ground- and Excited-State Properties of Re(I) Carbonyl Complexes Bearing 2,2':6',2″-Terpyridine and 2,6-Bis(pyrazin-2-yl)pyridine Coupled with π-Conjugated Aryl Chromophores.

Inorg Chem 2021 Nov 30. Epub 2021 Nov 30.

Institute of Chemistry, University of Silesia, ninth Szkolna Str., 40-006 Katowice, Poland.

In the current work, comprehensive photophysical and electrochemical studies were performed for eight rhenium(I) complexes incorporating 2,2':6',2″-terpyridine (terpy) and 2,6-bis(pyrazin-2-yl)pyridine (dppy) with appended 1-naphthyl-, 2-naphthyl-, 9-phenanthrenyl, and 1-pyrenyl groups. Naphthyl and phenanthrenyl substituents marginally affected the energy of the MLCT absorption and emission bands, signaling a weak electronic coupling of the appended aryl group with the Re(I) center. The triplet MLCT state in these complexes is so low lying relative to the triplet IL that the thermal population of the triplet excited state delocalized on the organic chromophore is ineffective. Read More

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November 2021

Computational Simulation of H NMR Profiles of Complex Biofluid Analyte Mixtures at Differential Operating Frequencies: Applications to Low-Field Benchtop Spectra.

Magn Reson Chem 2021 Nov 30. Epub 2021 Nov 30.

Leicester School of Pharmacy, The Gateway, De Montfort University, Leicester.

Estimations of accurate and reliable NMR chemical shift values, coupling patterns and constants within a reasonable timeframe remains significantly challenging, and the unavailability of reliable software strategies for the prediction of low-field (e.g., 60 MHz) spectra from those acquired at higher operating frequencies hampers their direct comparison. Read More

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November 2021

Sequence-dependent twist-bend coupling in DNA minicircles.

Nanoscale 2021 Nov 30. Epub 2021 Nov 30.

Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Republic of Korea.

Looping of double-stranded DNA molecules with 100-200 base pairs into minicircles, catenanes, and rotaxanes has been suggested as a potential tool for DNA nanotechnologies. However, sharp DNA bending into a minicircle with a diameter of several to ten nanometers occurs with alterations in the DNA helical structure and may lead to defective kink formation that hampers the use of DNA minicircles, catenanes, and rotaxanes in nanoscale DNA applications. Here, we investigated local variations of a helical twist in sharply bent DNA using microsecond-long all-atom molecular dynamics simulations of six different DNA minicircles, focusing on the sequence dependence of the coupling between DNA bending and its helical twist. Read More

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November 2021

Transition metal complexes with functionalized indenyl phosphine ligands: structures and catalytic properties.

Org Biomol Chem 2021 Nov 30. Epub 2021 Nov 30.

State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China.

Transition-metal indenyl complexes usually exhibit different reactivities compared with their cyclopentadienyl analogues. Up to now, at least 10 metal-indenyl bonding modes have been reported. Because of the "indenyl effect", transition-metal indenyl complexes usually show enhanced reactivity in substitution and related reactions. Read More

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November 2021

Anakinra restores cellular proteostasis by coupling mitochondrial redox balance to autophagy.

J Clin Invest 2021 Nov 30. Epub 2021 Nov 30.

Department of Medicine and Surgery, University of Perugia, Perugia, Italy.

Autophagy selectively degrades aggregation-prone misfolded proteins caused by defective cellular proteostasis. However, the complexity of autophagy may prevent the full appreciation of how its modulation could be used as a therapeutic strategy in disease management. Here we define a molecular pathway through which recombinant interleukin-1 receptor antagonist (IL-1Ra, anakinra) affects cellular proteostasis independently from the IL-1 receptor (IL-1R1). Read More

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November 2021

Effects of Composition Segregation in PMN-PT Crystals on Ultrasound Transducer Performance.

IEEE Trans Ultrason Ferroelectr Freq Control 2021 Nov 30;PP. Epub 2021 Nov 30.

This study investigates the relationship between the composition segregation in lead magnesium niobate-lead titanate (PMN-29%PT, PMN-29.5%PT, PMN-30%PT, PMN-30.5%PT, and PMN-31%PT) single crystals within morphotropic phase boundary (MPB) and the corresponding ultrasonic transducer performance through PiezoCAD modeling and real transducer testing. Read More

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November 2021

A handheld microwave thermoacoustic imaging system with an impedance matching microwave-sono probe for breast tumor screening.

IEEE Trans Med Imaging 2021 Nov 30;PP. Epub 2021 Nov 30.

Microwave-induced thermoacoustic imaging (MTAI) is a promising alternative for breast tumor detection due to its deep imaging depth, high resolution, and minimal biological hazards. However, due to the bulky size and complicated system configuration of conventional benchtop MTAI, it is limited to imaging various anatomical sites and its application in different clinical scenarios. In this study, a handheld MTAI system equipped with a compact impedance matching microwave-sono and an ergonomically designed probe was presented and evaluated. Read More

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November 2021

An Approximate Electromagnetic Model for Optimizing Wireless Charging of Biomedical Implants.

IEEE Trans Biomed Eng 2021 Nov 30;PP. Epub 2021 Nov 30.

Computational modeling is increasingly used to design charging systems for implanted medical devices. The design of these systems must often satisfy conflicting criteria, and fast electromagnetic solvers are pivotal for enabling multi-criteria optimization. In this paper, we look at wireless power transfer for implantable devices and the specific absorption rate and induced currents related to the implanted side of the design. Read More

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November 2021

Spin Fano Resonances in Chiral Molecules: An Alternative Mechanism for the CISS Effect and Experimental Implications.

Nano Lett 2021 Nov 30. Epub 2021 Nov 30.

School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona85287, United States.

Experiments on spin transport through a chiral molecule demonstrated the attainment of significant spin polarization, demanding a theoretical explanation. We report the emergence of spin Fano resonances as a mechanism in the chiral-induced spin-selectivity (CISS) effect associated with transport through a chiral polyacetylene molecule. Initializing electrons through optical excitation, we derive the Fano resonance formula for the spin polarization. Read More

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November 2021

Rapid Access to 3-Substituted Pyridines and Carbolines via a Domino, Copper-free, Palladium-Catalyzed Sonogashira Cross-Coupling/6π-Aza Cyclization Sequence.

J Org Chem 2021 Nov 30. Epub 2021 Nov 30.

Department of Pharmaceutical Sciences, Center for Pharmacometrics and Molecular Discovery, College of Pharmacy, Union University, Jackson 38305, Tennessee, United States.

Herein, we report a one-pot, three-component method for the preparation of 3-substituted pyridines and carbolines via copper-free, palladium-catalyzed Sonogashira cross-coupling with aryl iodides, followed by 6π-aza cyclization. This arylation cross-coupling/annulation cascade provides easy access to substituted, fused pyridines from readily available substrates in good yields (67-92%) with complete selectivity. Read More

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November 2021

Functional Dynamics of an Ancient Membrane-Bound Hydrogenase.

J Am Chem Soc 2021 Nov 30. Epub 2021 Nov 30.

Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden.

The membrane-bound hydrogenase (Mbh) is a redox-driven Na/H transporter that employs the energy from hydrogen gas (H) production to catalyze proton pumping and Na/H exchange across cytoplasmic membranes of archaea. Despite a recently resolved structure of this ancient energy-transducing enzyme [Yu et al. , , 1636-1649], the molecular principles of its redox-driven ion-transport mechanism remain puzzling and of major interest for understanding bioenergetic principles of early cells. Read More

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November 2021

Ultrasensitive Detection of Ruthenium by Coupling Cobalt and Cadmium Ion-Assisted Photochemical Vapor Generation to Inductively Coupled Plasma Mass Spectrometry.

Anal Chem 2021 Nov 30. Epub 2021 Nov 30.

National Research Council of Canada, 1200 Montreal Road, Ottawa, Ontario K1A 0R6, Canada.

An extremely sensitive methodology for the determination of Ru was developed by coupling photochemical vapor generation (PVG) analyte introduction with inductively coupled plasma mass spectrometry (ICPMS). PVG was undertaken with a thin-film flow-through photoreactor in a medium comprising 8 M formic acid in the presence of 10 mg L Co and 25 mg L Cd. The volatile product (presumably ruthenium pentacarbonyl) was generated in a flow injection mode, yielding an overall efficiency of 29% at a sample flow rate of 1. Read More

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November 2021

A Ferroelectric Metallomesogen Exhibiting Field-Induced Slow Magnetic Relaxation.

Chemistry 2021 Nov 30. Epub 2021 Nov 30.

Kumamoto University, Department of Chemistry, Graduate School of Science and Technology, 2-39-1 Kurokami, Chuo-ku, 860-8555, Kumamoto, JAPAN.

Magnetoelectric (ME) materials exhibiting coupled electric and magnetic properties are of significant interest because of their potential use in memory storage devices, new sensors or low-consumption devices. Herein, we report a new category of ME material that shows liquid crystal (LC), ferroelectric (FE), and single molecule magnet (SMM) behaviors. Co(II) complex incorporating alkyl chains of type [Co(3C16-bzimpy) 2 ](BF 4 ) 2 ( 1 ; 3C16-bzimpy = 2,2'-(4-hexadecyloxy-2,6-diyl)bis(1-hexadecyl-1H-benzo[d]imidazole)) displayed a chiral smectic C mesophase in the temperature range 321 K - 458 K, in which distinct FE behavior was observed, with a remnant polarization (88. Read More

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November 2021

Gap Junctional Coupling Between Retinal Astrocytes Exacerbates Neuronal Damage in Ischemia-Reperfusion Injury.

Invest Ophthalmol Vis Sci 2021 Nov;62(14):27

Department of Biological and Vision Sciences, SUNY College of Optometry, New York, NY, United States.

Purpose: Retinal astrocytes abundantly express connexin 43 (Cx43), a transmembrane protein that forms gap junction (GJ) channels and unopposed hemichannels. While it is well established that Cx43 is upregulated in retinal injuries, it is unclear whether astrocytic Cx43 plays a role in retinal ganglion cell (RGC) loss associated with injury. Here, we investigated the effect of astrocyte-specific deletion of Cx43 (Cx43KO) and channel inhibitors on RGC loss in retinal ischemia/reperfusion (I/R) injury and assessed changes in expression and GJ channel and hemichannel function that occur in I/R injury. Read More

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November 2021

3D Bacterial flagella as both synthetic biotemplates and ultrathin spacers for enhanced inter-particle coupling and solar energy harvesting.

Mater Horiz 2021 Jul 18;8(7):2097-2105. Epub 2021 Jun 18.

Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019-5300, USA.

Linear light-absorbing nanomaterials are ideal for film-based solar harvesting applications as they form porous structures that can maximize the absorption and minimize the reflection of the solar light. Conventional 1D nanochains of plasmonic nanoparticle assemblies can achieve significantly broadened optical absorption through surface plasmon coupling, but their optical bands are still not broad enough to absorb through the solar spectrum and thus are not efficient solar absorbers. Here we discovered first by simulation that 3D structured nanochains of plasmonic nanoparticles presented a remarkably increased optical broadening effect and much longer redshift of the optical peaks due to the enhanced inter-particle coupling effect. Read More

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Coupling the chemical reactivity of bimetallic surfaces to the orientations of liquid crystals.

Mater Horiz 2021 Jul 28;8(7):2050-2056. Epub 2021 May 28.

Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, USA.

The development of responsive soft materials with tailored functional properties based on the chemical reactivity of atomically precise inorganic interfaces has not been widely explored. In this communication, guided by first-principles calculations, we design bimetallic surfaces comprised of atomically thin Pd layers deposited onto Au that anchor nematic liquid crystalline phases of 4'-n-pentyl-4-biphenylcarbonitrile (5CB) and demonstrate that the chemical reactivity of these bimetallic surfaces towards Cl gas can be tuned by specification of the composition of the surface alloy. Specifically, we use underpotential deposition to prepare submonolayer to multilayers of Pd on Au and employ X-ray photoelectron and infrared spectroscopy to validate computational predictions that binding of 5CB depends strongly on the Pd coverage, with ∼0. Read More

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A two-dimensional multiferroic metal with voltage-tunable magnetization and metallicity.

Mater Horiz 2021 Aug 6;8(8):2316-2324. Epub 2021 Jul 6.

Department of Physics, Fudan University, Shanghai 200433, China.

We design a multiferroic metal that combines seemingly incompatible ferromagnetism, ferroelectricity, and metallicity by hole doping a two-dimensional (2D) ferroelectric with high density of states near the Fermi level. The strong magnetoelectric effect is demonstrated in hole-doped and arsenic-doped monolayer α-InSe using first-principles calculations. Taking advantage of the oppositely charged surfaces created by an out-of-plane polarization, the 2D magnetization and metallicity can be electrically switched on and off in an asymmetrically doped monolayer. Read More

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Direct formation of interlayer exciton in two-dimensional van der Waals heterostructures.

Mater Horiz 2021 Aug 15;8(8):2208-2215. Epub 2021 Jun 15.

New Energy Technology Engineering Laboratory of Jiangsu Province & School of Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.

In atomically thin two-dimensional van der Waals (2D vdW) heterostructures, spatially separated interlayer excitons play an important role in the optoelectronic performance and show great potential for the exploration of many-body quantum phenomena. A commonly accepted formation mode for interlayer excitons is via a two-step intralayer exciton transfer mechanism, namely, photo-excited intralayer excitons are initially generated in individual sublayers, and photogenerated electrons and holes are then separated into opposite sublayers based on the type-II band alignment. Herein, we expand the concept of interlayer exciton formation and reveal that bright interlayer excitons can be generated in one step by direct interlayer photoexcitation in 2D vdW heterostructures that have strong interlayer coupling and a short photoexcitation channel. Read More

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Electronic band structure of iridates.

Mater Horiz 2021 Aug 25;8(8):2151-2168. Epub 2021 May 25.

Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, Theodore Jorgensen Hall, University of Nebraska, 855 N 16th, P. O. Box 880299, Lincoln, Nebraska 68588-0299, USA.

In this review, an attempt has been made to compare the electronic structures of various 5d iridates (iridium oxides), with an effort to note the common features and differences. Both experimental studies, especially angle-resolved photoemission spectroscopy (ARPES) results, and first-principles band structure calculations have been discussed. This brings to focus the fact that the electronic structures and magnetic properties of the high-Z 5d transition iridates depend on the intricate interplay of strong electron correlation, strong (relativistic) spin-orbit coupling, lattice distortion, and the dimensionality of the system. Read More

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Singlet fission and triplet pair recombination in bipentacenes with a twist.

Mater Horiz 2021 Nov 30. Epub 2021 Nov 30.

Department of Chemistry, Columbia University, New York, New York 10027, USA.

We investigate triplet pair dynamics in pentacene dimers that have varying degrees of coplanarity (pentacene-pentacene twist angle). The fine-tuning of the twist angle was achieved by alternating connectivity at the 1-position or 2-positions of pentacene. This mix-and-match connectivity leads to tunable twist angles between the two covalently linked pentacenes. Read More

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November 2021

Flow effects on the surface properties of surfactant foam films.

Phys Chem Chem Phys 2021 Nov 30. Epub 2021 Nov 30.

School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China.

The surface electrostatic properties of liquid foam, involving the electrokinetic (EK) phenomena in the liquid-gas interface, have significant effects on the stability of the foam. Here, we established a theoretical model for ion transport in liquid films by combining the liquid flow and surface reaction. We found that the surface electrostatic properties of liquid foams were influenced unexpectedly by the pressure-induced flow. Read More

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November 2021

The influence of the cation structure on the basicity-related polarity of ionic liquids.

Phys Chem Chem Phys 2021 Nov 30. Epub 2021 Nov 30.

Department of Polymer Chemistry, Institute of Chemistry, Chemnitz University of Technology, Straße der Nationen 62, 09111 Chemnitz, Germany.

UV/Vis absorption data of ()-4-(2-[5-{4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl}thiene-2-yl]vinyl)-2-(dicyano-methylene)-3-cyano-5,5-dimethyl-2,5-dihydrofuran (ThTCF) as a solvatochromic probe is applied to examine the anion coordination strength ( of N(CN), BF, PF, N(Tf), CFCOO) as a function of the cation structure of ionic liquids. Several 1--alky-3-methylimidazolium- and tetraalkylammonium CH-NR-based ILs with different -alkyl chain lengths (R = -CH, -CH, -CH, -CH) are considered. UV/Vis absorption data of ThTCF show subtle correlations with hydrogen bond accepting (HBA) ability-related measurands such as Kamlet-Taft , Freire's , and Laurence parameter as a function of anion and cation structure. Read More

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November 2021

The occurrence, transformation and control of selenium in coal-fired power plants: status quo and development.

J Air Waste Manag Assoc 2021 Nov 30. Epub 2021 Nov 30.

Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding, 071003, PR China. E-mail: Fax; Tel.

As a trace element, selenium can cause serious harm to organisms when the concentration is too high. Coal-fired power plants are the main source of man-made selenium emissions. How to control the selenium pollution of coal-fired power plants to realize the renewable selenium and the sustainability of coal has not attracted enough attention from the whole world. Read More

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November 2021

Enantioselective Total Synthesis of Cepharatines Bioinspired Ring Reconstruction.

J Org Chem 2021 Nov 30. Epub 2021 Nov 30.

Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, Tokyo 184-8588, Japan.

We describe enantioselective total syntheses of cepharatines A-D, members of the hasubanan alkaloid family, which feature an unusual tetracyclic skeleton including an azabicyclo[3.3.1]nonane motif. Read More

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November 2021

Tunable and Practical Homogeneous Organic Reductants for Cross-Electrophile Coupling.

J Am Chem Soc 2021 Nov 30. Epub 2021 Nov 30.

Department of Process Research and Development, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States.

The syntheses of four new tunable homogeneous organic reductants based on a tetraaminoethylene scaffold are reported. The new reductants have enhanced air stability compared to current homogeneous reductants for metal-mediated reductive transformations, such as cross-electrophile coupling (XEC), and are solids at room temperature. In particular, the weakest reductant is indefinitely stable in air and has a reduction potential of -0. Read More

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November 2021

Microwave-Assisted Ruthenium- and Rhodium-Catalyzed Couplings of α-Amino Acid Ester Derived Phosphinamides with Alkynes.

Chem Asian J 2021 Nov 30. Epub 2021 Nov 30.

Zhengzhou University, College of Chemistry, CHINA.

Two different types of new phosphinamide α -amino ester derivatives have been prepared in moderate to high yields via ruthenium(II) and rhodium(III)-catalyzed ortho -C-H functionalization under microwave irradiation. Specifically, the ortho -alkenylated phosphinamides were produced through coupling of phosphinamides containing an α -substituted or α , α -disubstituted α -amino ester with internal alkynes under ruthenium catalysis. In contrast, Ru and the more effective Rh-catalyzed coupling of the α -unsubstituted glycine ester phosphinamide with alkynes resulted in formation of oxidative annulation products, phosphaisoquinolin-1-ones. Read More

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November 2021

Tandem vinyl radical Minisci-type annulation on pyridines: one-pot expeditious access to azaindenones.

Chem Commun (Camb) 2021 Nov 30. Epub 2021 Nov 30.

College of Chemistry, Beijing Normal University, Beijing 100875, China.

A new regiospecific alkylative/alkenylative cascade annulation of pyridines has been achieved whilst the corresponding classic Minisci alkylative annulation failed. This protocol provides a novel and expeditious access to azaindenones and related compounds cross-dehydrogenative coupling with the long-standing problem of C2/C4 regioselectivity of pyridines being well addressed. Read More

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November 2021

Evaluation of transport properties of biomembranes by means of Peusner network thermodynamics.

Acta Bioeng Biomech 2021 ;23(2):63-72

Department of Health Science, Jan Dlugosz University, Częstochowa, Poland.

Purpose: The R version of the Kedem-Katchalsky-Peusner (KKP) network equations is one of the basic research tools for membrane transport. For binary solutions of non-electrolytes containing a solvent and one solute, these equations include the Peusner resistance coefficients. The aim of the study was to assess the transport properties of biomembranes on the basis of the concentration characteristics of the coefficients: resistance, coupling, energy conversion efficiency and degraded and free energy fluxes. Read More

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January 2021