scholarly journals Studies on Ion Accumulation in Muscle Cells

1966 ◽  
Vol 49 (4) ◽  
pp. 819-843 ◽  
Author(s):  
Gilbert Ning Ling ◽  
Margaret Mary Ochsenfeld
Keyword(s):  
Induction Hypothesis ◽  
Protein Complexes ◽  
Total Concentration ◽  
Equilibrium Concentration ◽  
Sartorius Muscle ◽  
Competitive Effects ◽  
Adsorption Sites ◽  
Ionic Distribution ◽  
Equilibrium Distributions ◽  
Cs Ions

A comparison is made between the quantitative predictions of equilibrium ionic distribution in living cells according to the membrane theory (Donnan equilibrium) and according to the association-induction hypothesis. This comparison shows that both theories predict competitive effects of one permeant ion on the equilibrium concentration of another permeant ion; but within the limit of experimental accuracy only the association-induction model predicts quantitatively significant specific competition of one specified ion with the accumulation of another specified ion. The equilibrium distributions of K+, Rb+, and Cs+ ions in frog sartorius muscle were studied and quantitatively significant specific competition was demonstrated; these results favor the association-induction hypothesis (adsorption on cell proteins and protein complexes and partial exclusion from cell water). Based on this model we estimated that at 257deg;C, the apparent association constants for K+, Rb+, and Cs+ ion are 665, 756, and 488 (mole/liter)-1. We found that the total concentration of adsorption sites (no less than 240 mmole/kg of fresh cells) agrees with the analytically determined concentrations of ß- and γ-carboxyl groups of muscle cell proteins (260 to 288 mmole/kg).

The Influence of Biochar on Adsorption Behaviour of Triazine Herbicides in Different Soil Types

2021 ◽  
Author(s):  
Nadežda Stojanov ◽  
Tijana Zeremski ◽  
Snežana Maletić ◽  
Milorad Živanov ◽  
Jelena Tričković
Keyword(s):  
Organic Matter ◽  
Adsorption Capacity ◽  
Single Point ◽  
Organic Matter Content ◽  
Equilibrium Concentration ◽  
Soil Types ◽  
Batch Adsorption ◽  
Triazine Herbicides ◽  
Point Distribution ◽  
Adsorption Sites

<p>Biochar is promising material used to enhance organic matter content in soil and to mitigate climate change through carbon sequestration. In addition to that, biochar increases crop yield by means of improving soil capacity for water- and nutrient-holding capacity, and due to its adsorption capacity, it decreases mobility and bioavailability of organic pollutants and heavy metals. Biochar (BC) is a carbon-rich and porous material produced by pyrolysis of biomass under oxygen-limited conditions. The unwanted spread of pesticides to the environment and their leaching into the groundwater is of great concern. The aim of this work is to investigate the potential of BC to improve the adsorption capacity for two triazine herbicides in three different soil types with various organic matter (OC) content. Triazine herbicides (terbuthylazine and atrazine) were chosen as the most widely used pesticides in recent decades. The main difference among between three different soils types used in the study is in their OM content, which was 0.48%, 2.34% and 4.12%, respectively for Soil1, Soil2, and Soil3. The BC used in this work is commercially available compost-activated biochar produced by pyrolysis of beechwood chips at 700 <sup>o</sup>C. A batch adsorption experiments were conducted to investigate herbicide adsorption in soil without BC and with the amendment of BC (0, 1, 5, and 10%). The concentration of herbicides in the aqueous phase at equilibrium (which is achieved after 72 h) was determined by GC-MS. The adsorption isotherms were well described with the Freundlich model (R<sup>2</sup> values range from 0.714 to 0.998). Values of Freundlich exponent <em>n</em> were less than 1 (from 0.314 to 0.897), which indicates that the isotherms are of L-type. This shows that with the increase of compound concentration relative adsorption decreases because of the saturation of adsorption sites. Single-point distribution coefficients (<em>K<sub>d</sub></em>) were calculated at selected equilibrium concentration (<em>c<sub>e</sub></em>= 100 µg dm<sup>–3</sup>). <em>K<sub>d</sub></em> values increased with an increase of BC content, especially for 5% and 10% of BC amendment. <em>K<sub>d</sub></em> values of atrazine in Soil1 were in the range 1.91–14.55, in Soil2 from 4.76–15.65, and in Soil3 from 4.79–20.11, while <em>K<sub>d</sub></em> values of terbuthylazine ranged from 1.14–30.92 in Soil1, from 14.13–50.74 in Soil2, and from 12.65–47.03 in Soil3. In unamended Soil1 the adsorption of both herbicides was lower in comparison to unamended Soil2 and Soil3, which is in accordance with the well-known fact that the OC content of soil primarily affects the adsorption of pesticides. The adsorption capacity of Soil 2 and Soil 3 was not significantly different. It is observed that the adsorption of terbuthylazine is higher in all soil types, which is in accordance with its lower solubility and higher affinity for OM in comparison to atrazine. It is shown that sorption capacity of soil for pesticides could be improved by adding biochar into the soil, thus reducing herbicide mobility into the environment. Further studies will be conducted by column experiments to investigate more realistic environmental scenarios.</p>

Ionic Regulation in the Muscle Fibres of Carcinus Maenas

1955 ◽  
Vol 32 (2) ◽  
pp. 383-396
Author(s):  
J. SHAW
Keyword(s):  
Membrane Potential ◽  
Total Concentration ◽  
Carcinus Maenas ◽  
Chloride Ions ◽  
Sartorius Muscle ◽  
Muscle Fibres ◽  
Ion Distribution ◽  
Calcium And Magnesium ◽  
Whole Muscle ◽  
Total Muscle

1. Measurements have been made of the concentrations of potassium, chloride, calcium and magnesium, the conductivity and the membrane potential of single isolated fibres of the carpopodite extensor and flexor muscles of Carcinus maenas. 2. Analyses of whole muscles gave the total concentration of the cations as 224 mM./kg. H2O, of which potassium accounted for 120 mM./kg. and sodium 54 mM./kg. Of the anion fraction chloride only accounted for 54mM./kg. H2O. The analyses of the separated fibres were the same as for the whole muscle. 3. The average specific resistance of the fibres is 56Ω-cm. This represents a concentration of muscle ions of about 200 m.equiv./kg. and the electrolyte content of the muscle is not much more than a third of that of the blood. Between 72 and 91% of the total muscle fibre cations are present in an ionized form. 4. The average membrane potential is 58 mV. The ratios of the concentrations of potassium ions and chloride ions in the blood and muscle fibres suggest that these ions may be passively distributed across the membrane. The low concentration of sodium ions in the fibre probably indicates the operation of a ‘sodium pump’ as has been proposed for vertebrate muscles. The distribution of calcium and magnesium cannot be explained in simple terms. 5. The correspondence between the equilibrium potentials for potassium and chloride ions and the membrane potential suggests that theory of ion distribution put forward by Boyle & Conway for frog's sartorius muscle may also be applicable to Carcinus muscles.

scholarly journals Adsorption Behaviors of 17α-Ethinylestradiol in Sediment-Water System in Northern Taihu Lake, China

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Yonghua Wang ◽  
Liangfeng Hu ◽  
Qiuying Wang ◽  
Guanghua Lu ◽  
Yi Li
Keyword(s):  
Adsorption Capacity ◽  
Taihu Lake ◽  
Ph Value ◽  
Water System ◽  
Freundlich Isotherm ◽  
Hydroxyl Group ◽  
High Concentration ◽  
Competitive Effects ◽  
Adsorption Sites ◽  
Ph Values

Adsorption behavior of 17α-ethinylestradiol (EE2) in northern Taihu Lake sediment was analyzed by using batch equilibrium experiment. Freundlich isotherm could describe the adsorption thermodynamic behavior of EE2 in sediment. Sediment organic matter (SOM) contents had important impacts on the adsorption capacity for EE2. The pH values also influenced the adsorption capacity for EE2. Increase of pH value could decrease the EE2 adsorption, which might be due to the electrostatic repulsion between the anionic form of EE2 and sediments with negative charge under high pH values. Competitive effects of bisphenol A (BPA) on EE2 adsorption were further analyzed. The results showed that low concentration BPA did not have significant influences on EE2 adsorption. However, high concentration BPA could reduce EE2 adsorption, which might be due to the similar molecular diameter of BPA with adsorption sites and one more benzene ring with a hydroxyl group in BPA. These results provide primary information of EE2 adsorption in sediment-water system in Taihu Lake, which is useful for the environmental risk assessment and management of EE2 in studied area.

scholarly journals THE RELATIONSHIP BETWEEN SODIUM, POTASSIUM, AND CHLORIDE IN AMPHIBIAN MUSCLE

1957 ◽  
Vol 40 (5) ◽  
pp. 753-777 ◽  
Author(s):  
Shirley E. Simon ◽  
F. H. Shaw ◽  
Susanne Bennett ◽  
Margaret Muller
Keyword(s):  
Intact Animal ◽  
External Solution ◽  
Sartorius Muscle ◽  
Carrier System ◽  
Sodium Potassium ◽  
Adsorption Sites ◽  
Cellular Volume ◽  
The Relationship ◽  
Normal Ringer

The Na,+ Cl-, and K+ content of toad plasma and the sartorius muscle has been determined. Although the Na+ and Cl- level of the muscles in the living animal varied greatly (0 to 38.0 m.eq. per kg., and 0 to 31.8 m.eq. per kg. respectively) the K+ level was subject to a smaller variation (76.5 to 136 m.eq. per kg.). There was a direct relationship between Na+ and Cl-, which was independent of the K+ level. There is a closely related gain of Na+ and Cl- when muscle is soaked in normal Ringer. These gains are not related to the K+ loss, frequently found on soaking. The relationship between the three ions was studied in a large series of 124 muscles in normal Ringer. As found in vivo, there was a correlation between Na+ and Cl.- This correlation was independent of K+ content, except when this was abnormally low. Alteration of the external NaCl level produced concomitant changes in the internal levels of these ions. Alteration of the external KCl level produced an increase in internal Cl- similar to that found with high NaCl solutions, but the amount of K+ entering the cell was approximately one-third of the external increase. Removal of K+ from the external solution did not result in a loss of K+ from the cell, although there was an adequate amount of Cl- present to accompany it. The results cannot be reconciled with either a Donnan concept for the accumulation of K+, or a linked carrier system. A theory is proposed to account for the ionic differentiation within the cell. The K+ is assumed to be adsorbed onto an ordered intracellular phase. The normal metabolic functioning of the cell is necessary to maintain the specificity of the adsorption sites. There is another intracellular phase, which lacks the structural specificity for K+, and which contains Na+, Cl-, and K+ in equilibrium with the external solution. The dimensions of the free intracellular phase will vary from cell to cell, but it will be smaller in the intact animal, and will increase on soaking in normal Ringer, until it is approximately one-third of the total cellular volume. The increase in this phase may be ascribed to a decrease in the energy available to maintain the ordered phase.

Determination of the silver concentration with ion-selective electrode potentiometry

2020 ◽  
Author(s):  
Nataliia Chupakhina ◽  
Oleg Novikov ◽  
Pavel Maslennikov ◽  
Galina Chupakhina
Keyword(s):  
Total Concentration ◽  
Equilibrium Concentration ◽  
Chloride Content ◽  
Silver Concentration ◽  
Ion Selective Electrode ◽  
Selective Electrode ◽  
Minimum Concentration ◽  
Total Chloride ◽  
Chloride Solutions ◽  
The Stability

<p>For technological control of hydrometallurgical processes, it is especially important to obtain data on element concentrations with an express method. Potentiometry on an ion-selective electrode makes it possible to determine concentrations in real time. We propose a method for calculation of silver concentrations for chloride solutions.</p><p>In chloride solutions, silver is present in several forms: the cation [Ag<sup>+</sup>] and the complexes [AgCl], [AgCl<sub>2</sub>]<sup>-</sup>, [AgCl<sub>3</sub>]<sup>2-</sup>, [AgCl<sub>4</sub>]<sup>3-</sup>. The ion-selective electrode is calibrated using an AgNO<sub>3</sub> solution that contains exclusively Ag<sup>+</sup> cations; therefore, it actually determines only the cation content. However, in chloride solutions the cationic form of silver is present in a minimum concentration. Complexes with chloride anions have an opposite charge and are not fixed during the analysis. The total silver concentration can be estimated by measuring the total chloride content in the sample. Using the reference data on the stability constants and information on the concentration of silver cations obtained with potentiometry on an ion-selective chlorine-silver electrode we developed a mathematical model in order to calculate the total silver concentration. Using this model, the total concentration of all the forms of silver was calculated. The data are summarized in Table 1.</p><p>Calculating the equilibrium concentration we found that in high-salinity solutions silver prevails in the form of [AgCl<sub>4</sub>]<sup>3-</sup>. All the other complexes are present in smaller quantities. This result shows that it is important to take into account the complexes formation in potentiometric measurements on ion-selective electrodes.</p><p> </p>

Adsorption Site of Cs+ in Bentonite: Determination by EXAFS

2003 ◽  
Author(s):  
M. Nakano ◽  
K. Kawamura ◽  
K. Hara ◽  
K. Amemiya
Keyword(s):  
Ab Initio ◽  
Coordination Number ◽  
Room Temperature ◽  
Structural Parameters ◽  
Dry Weight ◽  
Water Interface ◽  
Basal Surface ◽  
Coordination Numbers ◽  
Adsorption Sites ◽  
Cs Ions

This study elucidated the location where Cs atoms resided at the solid–water interface in smectite hydrates that composed bentonite using EXAFS spectroscopy. Samples were prepared by adding 4ml of a 0.1M CsCl solution to 2g dry weight of suspended KunipiaF bentonite at pH 3.9, 7.1, and 9.8. The Cs K-edge absorption was measured in transmission mode at a synchrotron, Spring-8, Japan, using a Si(311) monochromator at room temperature for the wet paste and air-dried compacted samples. Data were analyzed with the program TECHXAS. The structural parameters were determined by a two-oxygen-shell fit using the ab initio program FEFF6 and ATOMS code. EXAFS analyses have suggested that for air-dried samples the first shell consisted of about 5O at a distance of 3.19–3.20 Å, and the second shell consisted of about 7O at a distance of 3.59–3.60 Å. For the wet paste, the first shell was observed at a distance of 3.15–3.16 Å with the coordination number of about 7O. The second shell consisted of about 6O at a distance of 3.59–3.60 Å. Debye-waller factors of the first oxygen shells were 0.021 and 0.04 Å2 for the air-dried and wet paste samples, respectively. For the second oxygen shells they were 0.039 and 0.052 Å2, respectively. Based on coordination numbers and Debye-waller factors, it concluded that the adsorption sites of Cs+ on smectite hydrates were positioned near the edge of the oxygen hexagonal cavity of the siloxane sheets on basal surface, and appeared between two aluminol sheets at fractured sections, assuming that the first shells were formed by oxygen of inter-layer water, and that the second shells consisted of oxygen forming clay minerals. Furthermore, in the wet paste Cs ions were considered to form incomplete inner-sphere-like complexes and to roam freely in inter-layer water in smectite.

scholarly journals Hydrothermal Desorption of Cs with Oxalic Acid from Hydrobiotite and Wastewater Treatment by Chemical Precipitation

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3284
Author(s):  
Sung-Man Kim ◽  
In-Ho Yoon ◽  
Ilgook Kim ◽  
June-Hyun Kim ◽  
So-Jin Park
Keyword(s):  
Oxalic Acid ◽  
Optimal Dose ◽  
Chemical Precipitation ◽  
Second Step ◽  
Optimal Conditions ◽  
Mass Ratio ◽  
Waste Solution ◽  
Adsorption Sites ◽  
Washing Wastewater ◽  
Cs Ions

A hydrobiotite (HBT) clay contains more cesium (Cs)-specific adsorption sites than illitic clay, and the capacity of frayed edge sites can increase as the weathering of micaceous minerals proceeds. Thus, Cs can be selectively adsorbed to HBT clay. In this study, we investigated the removal efficiency of non-radioactive (133Cs) and radioactive (137Cs) Cs from HBT, using oxalic acid. We found the minimum optimal concentration of 0.15 M oxalic acid removed more than 90% of Cs. Subsequently, cations and Cs ions were removed using Ca(OH)2 and sodium tetraphenylborate (NaTPB) to treat the washing wastewater generated at the optimum concentration of the desorbent (0.15 M oxalic acid). In order to remove cations and heavy metal ions in the waste solution, Ca(OH)2 was treated at a mass ratio of 0.025 g/mL and pH 9–10 to derive optimal conditions. As a final step, to remove Cs, NaTPB was treated with a mass ratio of 2 mg/mL and reduced to below 0.1 mg/L Cs to find the optimal dose. The novelty of this study is that the amount of radioactive waste can be drastically reduced by removing the non-radioactive cations and heavy metals separately in the first step and removing the remaining radioactive Cs in the second step.

scholarly journals Adsorption of Tungsten on Alumina from Sodium Tungstate Solutions. Estimation of Equilibrium and Kinetic Parameters

1994 ◽  
Vol 11 (3) ◽  
pp. 133-143 ◽  
Author(s):  
L.R. Pizzio ◽  
C.V. Cáceres ◽  
M.N. Blanco
Keyword(s):  
Kinetic Parameters ◽  
Sodium Tungstate ◽  
Total Concentration ◽  
Thin Layers ◽  
Strong Interactions ◽  
Tetrahedral Symmetry ◽  
Monomeric Species ◽  
Adsorption Sites ◽  
Tungsten Concentration ◽  
Do So

The tungsten adsorption isotherm from aqueous solutions of sodium tungstate on to alumina at 20°C has been studied. The isotherm shape was in agreement with that predicted by the classic Langmuir equation. This model was therefore fitted to the experimental data in order to determine the adsorption equilibrium constant and the total concentration of adsorption sites. Kinetic parameters of adsorption were also determined. To do so, a theoretical model that predicts the tungsten concentration profiles in impregnated thin layers was fitted to the experimental profiles. The diffuse reflectance spectra of dried samples used for isotherm determination and of thin alumina layers impregnated with tungsten solutions exhibit a band at 215 nm which is accompanied by a shoulder at 250 nm. For samples having a greater tungsten concentration, the shoulder develops and then transforms into a second band. The maximum at the lowest wavelength (first maximum) is assumed to correspond to tungsten in a tetrahedral coordination (monomeric species) while the second maximum is due to distortion in the tetrahedral symmetry caused by strong interactions between the support and the monomeric species.

scholarly journals The equivalence of quasi-chemical and statistical description of adsorbate molecule association in a localised adsorption monolayer on a homogeneous solid surface

2018 ◽  
Vol 65 (4) ◽  
pp. 25-38
Author(s):  
Jerzy K. Garbacz ◽  
Mariusz Kozakiewicz
Keyword(s):  
Canonical Ensemble ◽  
Equilibrium Concentration ◽  
Critical Conditions ◽  
Homogeneous Surface ◽  
Adsorption Sites ◽  
Solid Adsorbent ◽  
Adsorption Equation ◽  
Correct Form ◽  
Adsorption Monolayer ◽  
Association Of Molecules

Abstract The analysis of Berezin and Kiselev’s concept assuming linear association of molecules in a localised adsorption monolayer on the homogeneous surface of a solid adsorbent was carried out. An inconsistency due to the lack of consideration of equilibrium concentration of free adsorption sites in the formulation of the expression for the association constant has been pointed out. It was shown that the correct form of this function leads to the final adsorption equation being identical to the specific case of the Fowler-Guggenheim equation. The obtained result has been generalised to cases of branched adsorbateadsorbate associations. A new adsorption equation limiting the association to at most the dimers has been introduced. Critical conditions for the two-dimensional condensation of the adsorption layer were determined. By applying the formalism of canonical ensemble, full equivalence of the phenomenological and statistical methods was demonstrated in the description of the intermolecular interactions in the localised adsorption monolayer.

The Network Parameters Of The T-System In Frog Muscle Measured With The High Voltage Electron Microscope.

1975 ◽  
Vol 33 ◽  
pp. 550-551 ◽  
Author(s):  
Brenda R. Eisenberg ◽  
Lee D. Peachey
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Voltage ◽  
Sartorius Muscle ◽  
High Voltage Electron Microscopy ◽  
Network Parameters ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
T System

Analysis of the electrical properties of the t-system requires knowledge of the geometry of the t-system network. It is now possible to determine the network parameters experimentally by use of high voltage electron microscopy. The t-system was marked with exogenous peroxidase. Conventional methods of electron microscopy were used to fix and embed the sartorius muscle from four frogs. Transverse slices 0.5-1.0 μm thick were viewed at an accelerating voltage of 1000 kV using the JEM-1000 high voltage electron microscope at Boulder, Colorado and prints at x5000 were used for analysis.The length of a t-branch (t) from node to node (Fig. 1a) was measured with a magnifier; at least 150 t-branches around 30 myofibrils were measured from each frog. The mean length of t is 0.90 ± 0.11 μm and the number of branches per myofibril is 5.4 ± 0.2 (mean ± SD, n = 4 frogs).

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