apparent equilibrium
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2021 ◽  
Vol 27 (6) ◽  
pp. 210355-0
Author(s):  
Ralte Malsawmdawngzela ◽  
Lalhmunsiama ◽  
Diwakar Tiwari

The aim of this study was to synthesize novel and highly efficient functionalized material (BNMPTS) for selective elimination of Cu<sup>2+</sup> and Cd<sup>2+</sup> from aqueous waste. The detailed insights of solid/solution interactions were investigated by X-Ray photoelectron spectroscopic analyses. The grafting of silane caused for significant decrease in specific surface area of bentonite from 41.14 to 4.65 m<sup>2</sup>/g. The functionalized material possessed significantly high sorption capacity (12.59 mg/g for Cu<sup>2+</sup> and 13.19 mg/g for Cd<sup>2+</sup>) and selectivity for these cations. The material showed very high elimination efficiency at a wide range of pH ~2.0 to 7.0 for Cu<sup>2+</sup>, ~3.0 to 10.0 for Cd<sup>2+</sup> and concentration (1.0 to 25.0 mg/L) for Cu<sup>2+</sup> and Cd<sup>2+</sup>. A rapid uptake of these two cations achieved an apparent equilibrium within 60 minutes of contact. The increased level of background electrolyte concentrations (0.0001 to 0.1 mol/L) did not affect the elimination efficiency of these two cations by BNMPTS. Moreover, the common coexisting ions did not inhibit the removal of these toxic ions. Furthermore, high breakthrough volumes i.e., 1.4 and 3.69 L for Cu<sup>2+</sup>, 2.6 and 6.64 L for Cd<sup>2+</sup> was obtained using 0.25 and 0.50 g of BNMPTS respectively in a fixed-bed column operations.


Blood ◽  
2021 ◽  
Author(s):  
Henrik Østergaard ◽  
Jacob Lund ◽  
Per Jr Greisen ◽  
Stine Kjellev ◽  
Anette Henriksen ◽  
...  

Hemophilia A (HA) is a bleeding disorder resulting from deficient Factor VIII (FVIII), which normally functions as a cofactor to activated Factor IX (FIXa) that facilitates activation of Factor X (FX). To mimic this property in a bispecific antibody (biAb) format, a screening was conducted to identify functional pairs of anti-FIXa and anti-FX antibodies, followed by optimization of functional and biophysical properties. The resulting biAb (Mim8) assembled efficiently with FIXa and FX on membranes, and supported activation with an apparent equilibrium dissociation constant (KD) of 16 nM. Binding affinity with FIXa and FX in solution was much lower, with KD-values for FIXa and FX of 2.3 and 1.5 µM, respectively. In addition, the activity of Mim8 was dependent on stimulatory activity contributed by the anti-FIXa arm, which enhanced the proteolytic activity of FIXa by four orders of magnitude. In hemophilia A plasma and whole blood, Mim8 normalized thrombin generation and clot formation with potencies 13 and 18 times higher than a sequence-identical analog of emicizumab, respectively. A similar potency difference was observed in a tail-vein transection model in hemophilia A mice, while reduction of bleeding in a severe tail-clip model was observed only for Mim8. Furthermore, the pharmacokinetics of Mim8 were investigated and a half-life of 14 days demonstrated in cynomolgus monkey. In conclusion, Mim8 is a FVIIIa-mimetic with a potent and efficacious hemostatic effect based on preclinical data.


2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Takeshi Ohba ◽  
Muga Yaguchi ◽  
Urumu Tsunogai ◽  
Masanori Ito ◽  
Ryo Shingubara

AbstractDirect sampling and analysis of fumarolic gas was conducted at Ebinokogen Ioyama volcano, Japan, between December 2015 and July 2020. Notable changes in the chemical composition of gases related to volcanic activity included a sharp increase in SO2 and H2 concentrations in May 2017 and March 2018. The analyses in March 2018 immediately preceded the April 2018 eruption at Ioyama volcano. The isotopic ratios of H2O in fumarolic gas revealed the process of formation. Up to 49% high-enthalpy magmatic vapor mixed with 51% of cold local meteoric water to generate coexisting vapor and liquid phases at 100–160 °C. Portions of the vapor and liquid phases were discharged as fumarolic gases and hot spring water, respectively. The CO2/SO2 ratio of the fumarolic gas was higher than that estimated for magmatic vapor due to SO2 hydrolysis during the formation of the vapor phase. When the flux of the magmatic vapor was high, effects of hydrolysis were small resulting in low CO2/SO2 ratios in fumarolic gases. The high apparent equilibrium temperature defined for reactions involving SO2, H2S, H2 and H2O, together with low CO2/SO2 and H2S /SO2 ratios were regarded to be precursor signals to the phreatic eruption at Ioyama volcano. The apparent equilibrium temperature increased rapidly in May 2017 and March 2018 suggesting an increased flux of magmatic vapor. Between September 2017 and January 2018, the apparent equilibrium temperature was low suggesting the suppression of magmatic vapor flux. During this period, magmatic eruptions took place at Shinmoedake volcano 5 km away from Ioyama volcano. We conclude that magma sealing and transport to Shinmoedake volcano occurred simultaneously in the magma chamber beneath Ioyama volcano.


2021 ◽  
Vol 22 (3) ◽  
pp. 1159
Author(s):  
Leszek A. Kleczkowski ◽  
Abir U. Igamberdiev

Free magnesium (Mg2+) is a signal of the adenylate (ATP+ADP+AMP) status in the cells. It results from the equilibrium of adenylate kinase (AK), which uses Mg-chelated and Mg-free adenylates as substrates in both directions of its reaction. The AK-mediated primary control of intracellular [Mg2+] is finely interwoven with the operation of membrane-bound adenylate- and Mg2+-translocators, which in a given compartment control the supply of free adenylates and Mg2+ for the AK-mediated equilibration. As a result, [Mg2+] itself varies both between and within the compartments, depending on their energetic status and environmental clues. Other key nucleotide-utilizing/producing enzymes (e.g., nucleoside diphosphate kinase) may also be involved in fine-tuning of the intracellular [Mg2+]. Changes in [Mg2+] regulate activities of myriads of Mg-utilizing/requiring enzymes, affecting metabolism under both normal and stress conditions, and impacting photosynthetic performance, respiration, phloem loading and other processes. In compartments controlled by AK equilibrium (cytosol, chloroplasts, mitochondria, nucleus), the intracellular [Mg2+] can be calculated from total adenylate contents, based on the dependence of the apparent equilibrium constant of AK on [Mg2+]. Magnesium signaling, reflecting cellular adenylate status, is likely widespread in all eukaryotic and prokaryotic organisms, due simply to the omnipresent nature of AK and to its involvement in adenylate equilibration.


Author(s):  
Sander Brinkhof ◽  
Martijn Froeling ◽  
Rob P. A. Janssen ◽  
Keita Ito ◽  
Dennis W. J. Klomp

Abstract Objective Sodium concentration is responsible for (at least part of) the stiffness of articular cartilage due to the osmotic pressure it generates. Therefore, we hypothesized that we could use sodium MRI to approximate the stiffness of cartilage to assess early cartilage degeneration. Methods Four human tibial plateaus were retrieved from patients undergoing total knee replacement (TKR), and their cartilage stiffness mapped with indentation testing, after which samples were scanned in a 7 T MRI to determine sodium concentration. The relation of biomechanical parameters to MRI sodium and glycosaminoglycan (GAG) concentration was explored by a linear mixed model. Results Weak correlations of GAG concentration with apparent peak modulus (p = 0.0057) and apparent equilibrium modulus (p = 0.0181) were observed and lack of correlation of GAG concentration versus MRI sodium concentration was observed. MRI sodium concentration was not correlated with apparent peak modulus, though a moderate correlation of MRI sodium concentration with permeability was shown (p = 0.0014). Discussion and conclusion Although there was correlation between GAG concentration and cartilage stiffness, this was not similar with sodium concentration as measured by MRI. Thus, if the correlation between MRI sodium imaging and GAG concentration could be resolved, this strategy for assessing cartilage functional quality still holds promise.


Symmetry ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1748 ◽  
Author(s):  
Gregory S. Yablonsky ◽  
Denis Constales ◽  
Guy B. Marin

For a complex catalytic reaction with a single-route linear mechanism, a new, kinetico-thermodynamic form of the steady-state reaction rate is obtained, and we show how its symmetries in terms of the kinetic and thermodynamic parameters allow better discerning their influence on the result. Its reciprocal is equal to the sum of n terms (n is the number of complex reaction steps), each of which is the product of a kinetic factor multiplied by a thermodynamic factor. The kinetic factor is the reciprocal apparent kinetic coefficient of the i-th step. The thermodynamic factor is a function of the apparent equilibrium constants of the i-th equilibrium subsystem, which includes the (n−1) other steps. This kinetico-thermodynamic form separates the kinetic and thermodynamic factors. The result is extended to the case of a buffer substance. It is promising for distinguishing the influence of kinetic and thermodynamic factors in the complex reaction rate. The developed theory is illustrated by examples taken from heterogeneous catalysis.


Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3159 ◽  
Author(s):  
Natalia Komarova ◽  
Mariia Andrianova ◽  
Sergey Glukhov ◽  
Alexander Kuznetsov

Furaneol is an aroma compound which occurs naturally in foods and is used as an artificial flavor. Detection of furaneol is required in food science and food processing industry. Capture- Systematic Evolution of Ligands by EXponential enrichment (SELEX) protocol was applied for the isolation of an aptamer binding to furaneol, a small volatile organic substance contributing to the flavor of various products. Thirteen cycles of selection were performed. The resulting DNA pool was cloned, using blunt-end cloning, and ninety-six plasmids were sequenced and analyzed. Eight oligonucleotides were selected as aptamer candidates and screened for the ability to bind to furaneol, using three different methods—magnetic-beads associated elution assay, SYBR Green I assay, and exonuclease protection assay. One of the candidates was further characterized as an aptamer. The apparent equilibrium constant was determined to be (1.1 ± 0.4) µM, by the fluorescent method. The reported aptamer was applied for development of the ion-sensitive field-effect transistor (ISFET)-based biosensor, for the analysis of furaneol, in the concentration range of 0.1–10 µM.


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2800 ◽  
Author(s):  
Xingxing Liu ◽  
Jinchang Sheng ◽  
Jishan Liu ◽  
Yunjin Hu

The evolution of coal permeability is vitally important for the effective extraction of coal seam gas. A broad variety of permeability models have been developed under the assumption of local equilibrium, i.e., that the fracture pressure is in equilibrium with the matrix pressure. These models have so far failed to explain observations of coal permeability evolution that are available. This study explores the evolution of coal permeability as a non-equilibrium process. A displacement-based model is developed to define the evolution of permeability as a function of fracture aperture. Permeability evolution is tracked for the full spectrum of response from an initial apparent-equilibrium to an ultimate and final equilibrium. This approach is applied to explain why coal permeability changes even under a constant global effective stress, as reported in the literature. Model results clearly demonstrate that coal permeability changes even if conditions of constant effective stress are maintained for the fracture system during the non-equilibrium period, and that the duration of the transient period, from initial apparent-equilibrium to final equilibrium is primarily determined by both the fracture pressure and gas transport in the coal matrix. Based on these findings, it is concluded that the current assumption of local equilibrium in measurements of coal permeability may not be valid.


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