Investigation of the Aging Processes of Rubber. II. The Gold Reaction of Products of the Initial State of Oxidation

1934 ◽  
Vol 7 (1) ◽  
pp. 18-22
Author(s):  
B. Dogadkin ◽  
W. Balandina
Keyword(s):  
Electric Conductivity ◽  
Colloidal Gold ◽  
Chloride Solution ◽  
Maximum Intensity ◽  
Aqueous Extracts ◽  
Gold Chloride ◽  
Initial State ◽  
Experimental Conditions ◽  
Short Time

Abstract 1. Aqueous extracts of pale crepe, which were exposed to the radiation of a quartz lamp or which were masticated for a short time on cold mills, reduce slightly alkaline gold chloride solution with the formation of colloidal gold. 2. The maximum intensity of the gold reaction under the experimental conditions described lay within the limits of 20–30 minutes' exposure to radiation. 3. The maximum intensity for smoked sheets lies within the same range; however even before irradiation this rubber yields an extract which reduces gold chloride. 4. The electric conductivity of aqueous extracts increases continuously, and under the experimental conditions described began after 30 minutes of irradiation of the rubber. 5. The character of the variations in the intensity of the gold reaction and the electric conductivity of the extracts must be explained on the basis of corresponding concepts of the chemistry of changes in rubber during aging.

scholarly journals Kinetics of Non-Enzymatic Synthesis of Dipeptide Cbz-Phe-Leu with AOT Reversed Micelles

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1003
Author(s):  
Michiaki Matsumoto ◽  
Tadashi Hano
Keyword(s):  
Enzymatic Synthesis ◽  
Maximum Yield ◽  
Side Reactions ◽  
Experimental Conditions ◽  
Operational Conditions ◽  
Ph Dependency ◽  
Optimum Water Content ◽  
Short Time ◽  
Kinetics Of ◽  
Aot Reversed Micelles

The non-enzymatic synthesis of N-benzyloxycarbonyl-L-phenylalanyl-L-leucine (Cbz-Phe-Leu) from lipophilic N-benzyloxycarbonyl-L-phenylalanine (Cbz-Phe) and hydrophilic L-leucine (Leu), by N, N’-dicyclohexylcarbodiimide (DCC) as a condensing agent, was carried out using a reversed micellar system composed of bis(2-ethylhexyl) sodium sulfosuccinate (AOT) as a surfactant and isooctane. We successfully synthesized Cbz-Phe-Leu in a short time and investigated the effects of its operational conditions, the DCC concentration, w0, and the pH on the kinetic parameters and the maximum yields. For dipeptide synthesis, we had to add an excess of DCC with the substrates because of the side reactions of Cbz-Phe. From the pH dependency of the reactivity, a partially cationic form of Leu was better for a synthesis reaction because of the enrichment of Leu at the interface by anionic AOT. The optimum water content on the dipeptide synthesis was w0 = 28 due to the competition of the peptide synthesis and the side reactions. The maximum yield of Cbz-Phe-Leu was 0.565 at 80 h under optimum experimental conditions.

scholarly journals STRUCTURE-FUNCTION RELATIONSHIPS IN THE ADIPOSE CELL

1970 ◽  
Vol 46 (2) ◽  
pp. 342-353 ◽  
Author(s):  
Samuel W. Cushman
Keyword(s):  
Electron Microscopy ◽  
Fatty Acids ◽  
Colloidal Gold ◽  
Intracellular Transport ◽  
Nonesterified Fatty Acid ◽  
Experimental Conditions ◽  
Nonesterified Fatty Acids ◽  
Adipose Cell ◽  
Cell Functions ◽  
The Relationship

Pinocytic activity in the adipose cell has been examined by measuring the uptake of colloidal gold. Pinocytic activity occurs in the isolated adipose cell under all experimental conditions; a portion of the vesicular elements of the cell can be identified by electron microscopy as pinocytic in origin. The isolated adipose cell appears to take up serum albumin by pinocytosis. Pinocytic activity in the isolated adipose cell is enhanced by epinephrine, but not by insulin. The relationship between pinocytosis and the metabolic activity of the adipose cell has been studied by measuring simultaneously the uptake of radioactive colloidal gold, the incorporation of 14C-counts from U-glucose-14C into CO2, total lipid, triglyceride glycerol and triglyceride fatty acids, and the release of nonesterified fatty acids in the absence of hormones and in the presence of insulin or epinephrine. Correlations between hormone-produced alterations in lipid metabolism and in pinocytic activity suggest that intracellular nonesterified fatty acid levels are a factor in the regulation of both the cell's pinocytic activity and its metabolism and that pinocytosis in the adipose cell functions in the extracellular-intracellular transport of nonesterified fatty acids.

Growing commodity tilapia in various experimental conditions

2020 ◽  
pp. 26-36
Author(s):  
F. A. Altayeva
Keyword(s):  
Fish Farming ◽  
Biological Indicators ◽  
Fish Farms ◽  
Experimental Conditions ◽  
Fish Breeding ◽  
Closed Water ◽  
The Republic ◽  
Short Time ◽  
High Fish ◽  
Experimental Ponds

The article presents the results of growing tilapia to marketable weight in experimental sites (Chilikskoye pond pond farms LLP, KATU named after S. Seifullin JSC and Kapshagai spawning farm — 1973 LLP). In the process of carrying out research works, the methods generally accepted in fish farming, hydrochemistry, hydrobiology, hydrology, ichthyology, as well as foreign normative and technical guidelines and methodological instructions on the technology of growing commercial tilapia in industrial conditions were used. Monitoring of hydrochemical analyses of water in ponds, swimming pools, and closed water supply installations is given. Fish-breeding and biological indicators of tilapia grown in various experimental conditions are presented. The results of the studies have shown the real possibility of growing tilapia in various conditions of fish farms in Kazakhstan. Based on the results of the work, the following conclusions were made: — satisfactory fish-breeding indicators were obtained with various cultivation technologies (as when growing tilapia in polyculture and monoculture in ponds, in pools, as well as cultivation in the recirculation system); — the cultivation of tilapia in the experimental ponds of the fish farm of the Almaty region of the Republic of Kazakhstan has shown the possibility of obtaining high fish-breeding biological indicators of tilapia and the ability to grow to marketable mass in a short time; — as a result of experimental cultivation in various conditions, it was found that the survival rate was not lower than 97%; — as a result of the analysis of the profitability indices of the developed technologies, it was found that the most profitable was the technology of growing marketable tilapia products in monoculture ponds on water with a natural thermal regime in Chilik Pond Economy LLP.

Non-Equilibrium Critical Relaxation of Heisenberg Ferromagnets with Long-Range Correlated Defects

2012 ◽  
Vol 190 ◽  
pp. 39-42
Author(s):  
M. Medvedeva ◽  
Pavel V. Prudnikov
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Critical Behavior ◽  
Critical Exponents ◽  
Heisenberg Model ◽  
Three Dimensional ◽  
Initial State ◽  
Short Time ◽  
Theoretic Description ◽  
Good Agreement

The dynamic critical behavior of the three-dimensional Heisenberg model with longrangecorrelated disorder was studied by using short-time Monte Carlo simulations at criticality.The static and dynamic critical exponents are determined. The simulation was performed fromordered initial state. The obtained values of the exponents are in a good agreement with resultsof the field-theoretic description of the critical behavior of this model in the two-loopapproximation.

scholarly journals A Three-Step Process for the Bioconversion of Whey Permeate into a Glucose-Free D-Tagatose Syrup

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 647 ◽  
Author(s):  
Fadia V. Cervantes ◽  
Sawssan Neifar ◽  
Zoran Merdzo ◽  
Javier Viña-Gonzalez ◽  
Lucia Fernandez-Arrojo ◽  
...  
Keyword(s):  
Bacillus Stearothermophilus ◽  
Cheese Whey ◽  
Bifidobacterium Bifidum ◽  
Rare Sugar ◽  
Experimental Conditions ◽  
Whey Permeate ◽  
Mild Conditions ◽  
Stage Process ◽  
Short Time ◽  
Arabinose Isomerase

We have developed a sustainable three-stage process for the revaluation of cheese whey permeate into D-tagatose, a rare sugar with functional properties used as sweetener. The experimental conditions (pH, temperature, cofactors, etc.) for each step were independently optimized. In the first step, concentrated whey containing 180–200 g/L of lactose was fully hydrolyzed by β-galactosidase from Bifidobacterium bifidum (Saphera®) in 3 h at 45 °C. Secondly, glucose was selectively removed by treatment with Pichia pastoris cells for 3 h at 30 °C. The best results were obtained with 350 mg of cells (previously grown for 16 h) per mL of solution. Finally, L-arabinose isomerase US100 from Bacillus stearothermophilus was employed to isomerize D-galactose into D-tagatose at pH 7.5 and 65 °C, in presence of 0.5 mM MnSO4. After 7 h, the concentration of D-tagatose was approximately 30 g/L (33.3% yield, referred to the initial D-galactose present in whey). The proposed integrated process takes place under mild conditions (neutral pH, moderate temperatures) in a short time (13 h), yielding a glucose-free syrup containing D-tagatose and galactose in a ratio 1:2 (w/w).

Regulation of ketone body flux in septic patients

1989 ◽  
Vol 257 (5) ◽  
pp. E665-E674 ◽  
Author(s):  
M. Beylot ◽  
M. Guiraud ◽  
G. Grau ◽  
P. Bouletreau
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Parenteral Nutrition ◽  
Intravenous Infusion ◽  
Ketone Body ◽  
Normal Subjects ◽  
Initial State ◽  
Appearance Rate ◽  
Mild Hyperglycemia ◽  
Short Time

To assess the effect of sepsis on ketone body (KB) kinetics in humans, we measured in normal and septic subjects KB appearance rate (Ra) before (initial state) and during a rise of free fatty acids (FFA) level (intravenous infusion of a triglycerides emulsion). We studied normal subjects in postabsorptive state and septic patients when receiving an hypocaloric intravenous infusion of glucose and amino acids or 12 h after its interruption. When receiving glucose and amino acids infusion, septic patients had higher glucose and insulin levels than normal subjects, and despite lower FFA concentrations (255 +/- 44 vs. 480 +/- 51 mumol/l, P less than 0.05) comparable initial KB Ra (2.50 +/- 0.10 vs. 2.48 +/- 0.30 mumol.kg-1.min-1). Triglyceride infusion increased FFA to comparable values (septic 780 +/- 130, normal 730 +/- 45 mumol/l), but KB Ra rose in septic patients only to 3.7 +/- 1.1 instead of 7.7 +/- 1.1 mumol.kg-1.min-1 as in normal subjects (P less than 0.05). Somatostatin infusion decreased the hyperinsulinemia of septic patients but did not restore a normal ketogenesis. After interruption of nutriment infusion, septic patients had normal FFA levels and only mild hyperglycemia and hyperinsulinemia. Their initial KB Ra was not modified. However, their response of KB Ra (increase to 6.27 +/- 2.0 mumol.kg-1.min-1) to raised FFA levels (842 +/- 170 mumol/l) was comparable to the response of normal subjects. In conclusion, although septic patients receiving an hypocaloric parenteral nutrition had a depressed ketogenesis they were able to restore a normal ketogenic capacity after a short-time caloric deprivation. Glucose and/or insulin appears to have a major role in this modulation of hepatic ketogenesis.

Expert System for EPMA

1999 ◽  
Vol 5 (S2) ◽  
pp. 592-593
Author(s):  
C. Fournier ◽  
C. Merlet ◽  
P.F. Staub ◽  
O. Dugne
Keyword(s):  
Quantitative Analysis ◽  
Expert System ◽  
Reasonable Accuracy ◽  
Experimental Conditions ◽  
Sample Composition ◽  
Starting Point ◽  
Accuracy Of Results ◽  
Short Time ◽  
And Control ◽  
Selection Of

Analysis parameters for an electron microprobe are numerous, and the accuracy of the quantitative analysis is very sensitive to the selection of these experimental conditions. The expert system intends to optimize the choice of each analysis parameter as well as to automate the phases of a quantitative analysis on all kinds of materials. To summarise, the aim of the expert system is to simplify the procedures, improve the accuracy of results and control the analysis time. The figure 1 illustrates the various stages of the expert system.The starting point of the expert system is an interactive questionnaire concerning the sample,( ie, what is already known), and about the expectations on the analysis,( ie, the accuracy of the results and/or the duration of the analysis required by the operator). Then, the expert system performs a semi-quantitative analysis on the sample. Based on the acquisition of a wavelength qualitative spectrum, this method is a way to obtain the sample composition in a short time with the advantages of the WDS system, and with a reasonable accuracy.

scholarly journals Analysis of Rhythmic Patterns Produced by Spinal Neural Networks

2007 ◽  
Vol 98 (5) ◽  
pp. 2807-2817 ◽  
Author(s):  
Y. Mor ◽  
A. Lev-Tov
Keyword(s):  
Time Series ◽  
Statistical Significance ◽  
Wavelet Coherence ◽  
Motor Patterns ◽  
Experimental Conditions ◽  
Wide Range ◽  
Continuous Frequency ◽  
Pattern Generators ◽  
The Fourier Transform ◽  
Short Time

A network of spinal neurons known as central pattern generator (CPG) produces the rhythmic motor patterns required for coordinated swimming, walking, and running in mammals. Because the output of this network varies with time, its analysis cannot be performed by statistical methods that assume data stationarity. The present work uses short-time Fourier (STFT) and wavelet-transform (WT) algorithms to analyze the nonstationary rhythmic signals produced in isolated spinal cords of neonatal rats during activation of the CPGs. The STFT algorithm divides the time series into consecutive overlapping or nonoverlapping windows and repeatedly applies the Fourier transform across the signal. The WT algorithm decomposes the signal using a family of wavelets varying in scale, resulting in a set of wavelet coefficients presented onto a continuous frequency range over time. Our studies revealed that a Morlet WT algorithm was the tool of choice for analyzing the CPG output. Cross-WT and wavelet coherence were used to determine interrelations between pairs of time series in time and frequency domain, while determining the critical values for statistical significance of the coherence spectra using Monte Carlo simulations of white-noise series. The ability of the cross-Morlet WT and cross-WT coherence algorithms to efficiently extract the rhythmic parameters of complex nonstationary output of spinal pattern generators over a wide range of frequencies with time is demonstrated in this work under different experimental conditions. This ability can be exploited to create a quantitative dynamic portrait of experimental and clinical data under various physiological and pathological conditions.

scholarly journals Impact of a short-time exposure to different temperatures on wakening time of Vertigo antivertigo (Draparnaud, 1801) (Gastropoda: Eupulmonata: Vertiginidae)

2021 ◽  
Vol 29 (3) ◽  
pp. 186-189
Author(s):  
Zofia Książkiewicz-Parulska
Keyword(s):  
Room Temperature ◽  
Test Tube ◽  
High Humidity ◽  
Experimental Conditions ◽  
Time Exposure ◽  
Different Temperatures ◽  
Short Time

I checked experimentally how a short-time exposure to different temperatures: 1 °C, 24 °C and 34 °C in a high humidity affects wakening time of Vertigo antivertigo (Draparnaud). The snails were exposed to experimental conditions for 48 hours (each snail in a separate test tube, provided with food and a source of calcium). After that time, all the individuals were transferred to room temperature (24 °C) for counting the time needed for wakening. The shortest wakening time was noted for snails kept at 1 °C, the longest – for snails kept at room temperature of 24 °C.

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