acidic components
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Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Natalya N. Nikonova ◽  
Tatyana V. Hurshkainen ◽  
Oksana G. Shevchenko ◽  
Alexander V. Kuchin

Abstract In order to explore the extractives of conifers an effective and environmentally friendly method of extraction with aqueous-alkaline solution allowing to isolate up to 10.4% of extractive substances (ES) from pine wood greenery and up to 6.9% from larch wood greenery was investigated. The component fractional composition of aqueous-alkaline extracts was studied. The antioxidant fraction activity of neutral and acidic components isolated from the produced extracts was evaluated. It was found that these fractions have a high antioxidant activity, where the activity of larch extract components was higher than that of the respective components of pine extract. Due to their rich chemical composition and high biological activity, extracts of pine and larch wood greenery produced by aqueous-alkaline extraction have good application prospects as biologically active preparations.


2021 ◽  
Vol 37 (5) ◽  
pp. 545-556
Author(s):  
Byeong Hoon Lee

In this study, we aimed to elucidate the materialistic characteristics of 11 pieces of earthenware belonging to the Neolithic and Bronze Age excavated from Jeongseon Auraji, South Korea. As a result, the chemical composition of earthenwares belonging to the early Bronze Age was distributed in the intermediate area between the Neolithic and Bronze Age earthenwares, but no significant difference was confirmed based on their manufacturing period. Upon comparison, the earthenwares excavated from Jeongseon Auraji site were found to comprise less acidic components than those excavated from Yeongdong, and are characterized by the alkaline components depending on the excavated site. In the rare earth elements distribution pattern, all the analyzed earthenwares exhibited similar pattern, confirming that the raw materials present in the clay were the same. As a result of microstructure analysis, the clay particles and voids were found to be irregularly distributed in the analyzed earthenwares. Neolithic earthenwares exhibited many irregular voids, and an arrangement of aluminosilicate, including feldspar, was observed along with the clay substrate. Furthermore, we confirmed that the empty space in early Bronze Age earthenwares was filled with fine particles and cube crystals. Moreover, the main mineral phase of earthenwares excavated from Jeongseon Auraji exhibited similar composition, and therefore, there was no significant difference in the firing temperature of these earthenwares. The firing temperature of the earthenwares ranged from 750 to 850°C.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Reeba Susan Jacob ◽  
Cedric Eichmann ◽  
Alessandro Dema ◽  
Davide Mercadante ◽  
Philipp Selenko

The Parkinson's disease protein α-synuclein (aSyn) promotes membrane fusion and fission by interacting with various negatively charged phospholipids. Despite postulated roles in endocytosis and exocytosis, plasma membrane (PM) interactions of αSyn are poorly understood. Here, we show that phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidylinositol 3,4,5-trisphosphate (PIP3), two highly acidic components of inner PM leaflets, mediate plasma membrane localization of endogenous pools of αSyn in A2780, HeLa, SK-MEL-2 and differentiated and undifferentiated neuronal SH-SY5Y cells. We demonstrate that αSyn binds to reconstituted PIP2-membranes in a helical conformation in vitro and that PIP2 synthesizing kinases and hydrolyzing phosphatases reversibly redistribute αSyn in cells. We further delineate that αSyn-PM targeting follows phosphoinositide-3 kinase (PI3K)-dependent changes of cellular PIP2 and PIP3 levels, which collectively suggests that phosphatidylinositol polyphosphates contribute to αSyn's cellular function(s) at the plasma membrane.


2020 ◽  
Author(s):  
Nadezhda Titovna Berberova ◽  
Nadezhda Anatol’evna Pivovarova ◽  
Valentina Nikolaevna Storozhenko ◽  
Elena Vladimirovna Shinkar ◽  
Ivan Vladimorovich Smolyaninov

The tendency to reduce the content of sulfur compounds in particular H2S and low molecular thiols (RSH) in oil products sets the task of their extraction and disposal in order to obtain practically useful sulfur compounds. Hydrogen sulfide and thiols can be extracted from hydrocarbon fractions using N-methylpyrrolidone-as selective solvent. Hydrogen sulfide can be extracted from the residual oil products using a low energy exposure such as ultrasound and a constant magnetic field. The releasing gas is concentrated in N-methylpyrrolidone. Further, hydrogen sulfide and mercaptans can be used in the chemical synthesis of biologically active thioethers containing a catechol fragment. Another way of H2S and RSH utilization is the chemical adsorption of acidic components by modified polynuclear pivalate (acetate) zinc(II) silica gel. As a result of the interaction of complexes with H2S and RSH, it is possible to obtain zinc sulfide or zinc thiolates, which can be used in various fields of industry or agriculture. Hydrogen sulfide and thiols can also be applied in the electrochemical or microvaved assisted organic synthesis. This approach is promising from the standpoint of environmental safety of synthesis and low energy costs of the reactions. The SH-functionalization of hydrocarbons (indan, indene, decalin, tetralin, naphthalene and 1,2-dihydronaphthalene) leads to obtain biologically active compounds. Keywords: hydrogen sulfide, thiols, extraction, N-methylpyrrolidone, ultrasonic and magnetic treatment, microwave, redox activation


2020 ◽  
Author(s):  
Cédric Eichmann ◽  
Reeba Susan Jacob ◽  
Alessandro Dema ◽  
Davide Mercadante ◽  
Philipp Selenko

AbstractThe Parkinson’s disease protein α-synuclein (αSyn) promotes membrane fusion and fission by interacting with various negatively charged phospholipids. Despite postulated roles in endocytosis and exocytosis, plasma membrane (PM) interactions of αSyn are poorly understood. Here, we show that phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidylinositol 3,4,5-trisphosphate (PIP3), two highly acidic components of inner PM leaflets, mediate plasma membrane localization of endogenous pools of αSyn in A2780, HeLa, SH-SY5Y and SK-MEL-2 cells. We demonstrate that αSyn binds reconstituted PIP2-membranes in a helical conformation in vitro and that PIP2 synthesizing kinases and hydrolyzing phosphatases reversibly redistribute αSyn in cells. We further delineate that αSyn-PM targeting follows phosphoinositide-3 kinase (PI3K)-dependent changes of cellular PIP2 and PIP3 levels, which collectively suggests that phosphatidylinositol polyphosphates contribute to αSyn’s cellular function(s) at the plasma membrane.


Author(s):  
Gholam Hossein Hamedi ◽  
Amir Shabani ◽  
Yasaman Safargar

In order to increase the life of the asphalt mixture and reduce the cost of the pavement life cycle, methods must be provided to improve the quality. Accordingly, the effects of aggregate surface coating with hydrophobic material in order to modify the aggregate mixture’s polar properties and reduce its hydrophilic properties are investigated. To this end, limestone and granite aggregates, 60-70 bitumen, and Two types of additives were used as the primary materials for the construction of asphalt mixtures. Thermodynamic concepts with cyclic loading have been used to evaluate the effects of these additives. The results obtained in this study indicate that the hydrophobic coating on the aggregate surface has increased the acidic components and decreased the alkaline components of the surface free energy for both types of aggregates. These changes will increase the bitumen-aggregate adhesion and make a better coating of bitumen on the aggregate surface. The results based on thermodynamic concepts suggest that the aggregate surface coating has reduced the system’s separation energy and the desire for stripping. The results of the dynamic modulus in wet to dry conditions also approve this outcome. The combination of thermodynamic concepts and the cyclic loading results show that the coating on the aggregate surface has reduced the aggregate’s stripping from bitumen. It is also obvious that the samples made with granite aggregates, which have acidic properties, are prone to moisture damage and have a higher tendency to strip.


2020 ◽  
pp. 199-206
Author(s):  
Tat'yana Petrovna Kukina ◽  
Dmitriy Nikolayevich Shcherbakov ◽  
Nina Vital'yevna Panteleyeva ◽  
Ol'ga Iosifovna Sal'nikova ◽  
Petr Vladimirovich Kolosov

The composition of the sunflower oil deodorization distillate has been investigated. 18 acidic components have been identified, more than 40% of the composition of the studied sample falls on linoleic acid with F-vitamin activity. More than 30 components of neutral nature have been found that are of interest as bioactive compounds. Of these, 10 are phytosterols, 14 are triterpene alcohols, 5 are tocopherols. The diterpene hydrocarbons, alcohols and acids of the kauran structure found in the composition of deodorization distillate indicate that the original sunflower oil was native, since it is known that kauran derivatives are a chemotaxonomic marker of many plants of the compositae family, including sunflower. In addition to the above compounds, hydrocarbons (more than a quarter of the unsaponifiable matter), both aliphatic and diterpenic, in the studied sample, was found. Aliphatic components are predominantly unsaturated, which may indicate their artifact origin, i.e. they are the products of the dehydration of aliphatic alcohols. Phytadiene isomers, products of phytol dehydration and isomerization, have been found. The data obtained indicate the prospects for the use of oil deodorization distillate as a source of bioactive substances, cosmetic ingredients and pharmaceutical components.


Author(s):  
I. L. Poz ◽  
A. G. Strokov

Apart from its main electrolytes – sodium, potassium, calcium and magnesium – a dialysis fluid (DF) contains a buffer for correction of acidosis. A small amount of acid is added to the DF to prevent calcium and magnesium precipitation. Acetic acid has traditionally been used for this purpose. Several studies have shown that acetate ion, even in small concentrations, can cause a number of adverse events, such as low blood pressure, production of proinflammatory cytokines, etc. This literature review aims at considering alternative acidic components of DF, such as citric, hydrochloric, and succinic acids, as well as their advantages, possibilities and features of their use in wide clinical practice.


2020 ◽  
Vol 38 (4) ◽  
pp. 867-883
Author(s):  
Congge He ◽  
Zifei Fan ◽  
Chenshuo Zhang ◽  
Anzhu Xu ◽  
Lun Zhao ◽  
...  

Minimum miscible pressure is a key parameter to screen and design miscible gas injection projects. The aim of this paper is to establish a correlation with only a few input parameters to easily and accurately predict minimum miscible pressure for the reinjection of produced gas with high acidic components. First, the critical parameters of equation of state for each component of the crude oil were obtained through fitting pressure-volume-temperature (PVT) experimental results. Based on the analytically calculated minimum miscible pressures from mixing-cell method, an empirical correlation for predicting minimum miscible pressure in the displacement of crude oil by produced gas was regressed. Finally, the correlation’s accuracy was tested by comparing the minimum miscible pressures predicted from the new proposed correlation to other previous correlations and 20 experimental slim-tube minimum miscible pressures of 12 oil samples. The results indicate that the analytically calculated minimum miscible pressures from the mixing-cell method have a relative error of 0.5% compared to the slim-tube experiment results, which supports its reliability. Furthermore, the new proposed correlation is observed to be superior in terms of the average relative error being only 6.4% for all the 75 analytically calculated minimum miscible pressures and 20 experimental slim-tube minimum miscible pressures, which is lower than the average relative error obtained from other previous correlations.


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