calcium cations
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2021 ◽  
pp. 34-37
Author(s):  
Екатерина Владимировна Ульянова ◽  
Дарья Владиславовна Андриевская

Стабильность (розливостойкость) в течение длительного времени - одна из важных составляющих качественных характеристик спиртных напитков виноградного происхождения, в том числе коньяков. Коньяк представляет собой сложную многокомпонентную систему, включающую более 800 различных соединений, в том числе фенольный комплекс древесины дуба и минеральные вещества. В процессе длительного хранения под воздействием ряда факторов эти соединения, вступая во взаимодействие друг с другом, могут образовывать различные виды помутнений, что влечет за собой потерю товарного вида готовой продукции. Целью настоящей работы стало исследование влияния отдельных показателей физико-химического состава обработанных коньяков на изменение их стабильности в процессе хранения. В качестве объектов исследования использовали образцы обработанных розливостойких коньяков отечественного производства, которые были разделены в зависимости от возраста на четыре группы: I группа - 3-летние, 4-летние и 5-летние (23 образца); II группа - выдержанные «КВ» и выдержанные высшего качества «КВВК» (15 образцов); III группа - старые «КС» (9 образцов); IV группа - очень старые «ОС» (7 образцов). Образцы хранили в течение 6 мес. при температуре 22…25 °С, в условиях, не допускающих попадания прямых солнечных лучей. В процессе хранения проводили мониторинг изменения физико-химических показателей, розливостойкости и органолептических характеристик исследуемых образцов с периодичностью 1 раз в месяц. Установлено, что на всем протяжении хранения физико-химические показатели исследованных образцов оставались в пределах нормы. Однако, в отдельных образцах, на определенном этапе эксперимента (после 2 мес. хранения) было отмечено появление осадка. Кроме того, по результатам определения склонности к различным видам помутнений был отмечен рост доли коньяков, нестойких к необратимым коллоидным и кристаллическим помутнениям в трех группах, кроме IV группы. Полученные данные по исследованию структуры осадков и результаты тестов на розливостойкость согласуются с характером изменений массовых концентраций катионов натрия и кальция, а также фенольных соединений. В целом полученные результаты проведенных исследований показали необходимость контроля массовой концентрации катионов натрия и кальция, а также фенольных соединений при прогнозировании розливостойкости коньяков. One of the important components of the quality characteristics of alcoholic beverages of grape origin, including cognacs, is their stability (bottling resistance) for a long time. Cognac is a complex multicomponent system that includes more than 800 different compounds, including the phenolic complex of oak wood and minerals. During long-term storage, under the influence of a number of factors, these compounds, interacting with each other, can form various types of turbidity, which entails the loss of the presentation of the finished product. The aim of this work was to study the effect of individual indicators of the physical and chemical composition of processed cognacs on the change in their stability during storage. As objects of research, we used samples of processed bottling-resistant cognacs of domestic production, which were divided, depending on age, into four groups: Group I - three-year-old, four-year-old and five-year-old (23 samples); Group II - matured «KV» and matured of the highest quality «KVVK» (15 samples); Group III - old «KS» (9 samples); IV group - very old «OS» (7 samples). The samples were stored for 6 months at a temperature of 22…25 °C, in conditions out of direct sunlight. During storage, changes in physical and chemical parameters, bottling resistance and organoleptic characteristics of the samples under study were monitored at a frequency of 1 time per month. It was found that during the entire storage period, the physicochemical indicators of the studied samples remained within the normal range. However, in some samples, at a certain stage of the experiment (after 2 months of storage), the appearance of a precipitate was noted. In addition, according to the results of determining the tendency to various types of cloudiness, an increase in the proportion of cognacs unstable to irreversible colloidal and crystalline cloudiness was noted in three groups, except for group IV. The data obtained on the study of the structure of sediments and the results of tests for pouring resistance are consistent with the nature of changes in the mass concentrations of sodium and calcium cations, as well as phenolic compounds. In general, the results of the studies carried out showed the need to control the mass concentration of sodium and calcium cations, as well as phenolic compounds when predicting the pouring resistance of cognacs.


Author(s):  
Ilya V. Rogachevskii ◽  
Vera B. Plakhova ◽  
Valentina A. Penniyaynen ◽  
Stanislav G. Terekhin ◽  
Svetlana A. Podzorova ◽  
...  

A gamma-pyrone derivative, comenic acid, activates the opioid-like receptor-mediated signaling pathway that modulates the NaV1.8 channels in the primary sensory neuron membrane. These channels are responsible for generation of the nociceptive signal; gamma-pyrones can therefore have a great therapeutic potential as analgesics, and this effect deserves a deeper understanding. The novelty of our approach to the design of a medicinal substance is based on a combination of the data obtained on living neurons using very sensitive physiological methods and the results of quantum-chemical calculations. This approach allows to correlate the molecular structure of gamma-pyrones with their ability to evoke a physiological response of the neuron. Comenic acid can bind two calcium cations. One of them is chelated by the carbonyl and the hydroxyl functional groups, while another one forms the salt bond with the carboxylate anion. Calcium-bound gamma-pyrones are fundamentally different in electrostatic properties from the free gamma-pyrone molecules. These two calcium ions are the key elements involved in ligand-receptor binding. It is very likely ion-ionic interactions between these cations and anionic functional groups of the opioid-like receptor that activate the latter. The calculated intercationic distance of 9.5 Å is a structural criterion for effective ligand-receptor binding of calcium-bound gamma-pyrones.


2021 ◽  
Vol 66 (8) ◽  
pp. 1169-1175
Author(s):  
L. I. Podzorova ◽  
A. A. Il’icheva ◽  
V. E. Kutuzova ◽  
V. P. Sirotinkin ◽  
O. S. Antonova ◽  
...  

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1521
Author(s):  
Janjira Jinnoros ◽  
Bhundit Innawong ◽  
Patchimaporn Udomkun ◽  
Pramuk Parakulsuksatid ◽  
Juan L. Silva

The effect of the pulsed-vacuum stimulation (PVS) on the external gelation process of calcium-alginate (Ca-Alg) hydrogel balls was studied. The process was conducted at four different working pressures (8, 35, 61, and 101 kPa) for three pulsed-vacuum cycles (one cycle consisted of three repetitions of 10 min of depressurization and 10 min of vacuum liberation). The diffusion coefficients (D) of calcium cations (Ca2+) gradually reduced over time and were significantly pronounced (p < 0.05) at the first three hours of the external gelation process. The rate of weight reduction (WR) and rate of volume shrinkage (Sv) varied directly according to the D value of Ca2+. A significant linear relationship between WR and Sv was observed for all working pressures (R2 > 0.91). An application of a pulsed vacuum at 8 kPa led to the highest weight reduction and shrinkage of Ca-Alg hydrogel samples compared to other working pressures, while 61 kPa seemed to be the best condition. Although all textural characteristics (hardness, breaking deformation, Young’s modulus, and rupture strength) did not directly variate by the level of working pressures, they were likely correlated with the levels of WR and Sv. Scanning electron micrographs (SEM) supported that the working pressure affected the characteristics of Ca-Alg hydrogel structure. Samples stimulated at a working pressure of 8 kPa showed higher deformation with heterogenous structure, large cavities, and looser layer when compared with those at 61 kPa. These results indicate the PVS is a promising technology that can be effectively applied in the external gelation process of Ca-Alg gel.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2899
Author(s):  
Natalya V. Efimova ◽  
Alla P. Krasnopyorova ◽  
Galina D. Yuhno ◽  
Dmitry S. Sofronov ◽  
Mirosław Rucki

In the paper, investigation results of the uptake efficiency of radionuclides 60Co, 90Sr, and 137Cs dissolved in water onto iron oxides α-Fe2O3 and Fe3O4 are presented. It was found that sorption efficiency increased for higher pH values. Independent of the oxide nature, the uptake characteristics are the best toward 60Co and the worst toward 137Cs, forming the row as follows: 60Co > 90Sr > 137Cs. The highest sorption ability at pH 9 was found for magnetite Fe3O4, which was 93%, 73%, and 26% toward 60Co, 90Sr, and 137Cs, respectively, while the respective percentages for hematite α-Fe2O3 were 85%, 41%, and 18%. It was assumed that the main sorption mechanism was ion exchange. That may explain some decrease of the sorption efficiency in drinking water due to the interfering presence of magnesium and calcium cations. The obtained results indicated the feasibility of the tested sorbents and their merits, especially in terms of relatively high uptake coefficients, low costs, availability, and lack of toxicity.


Author(s):  
Zinoviev S.V. ◽  
Plekhova N.G. ◽  
Radkov I.V.

Purpose of the study: to assess the histochemical features of the localization of calciumdependent receptors of the left lung cell membrane on the 8th day of experimental compensated traumatic brain injury. Materials and methods: The object of the study was male albino outbred rats, three months old, weight 270-300 grams. Created two groups of animals: 1 - control: intact rats; 2- experimental: rats with TBI. To create a head injury, a model of a falling weight was used. Animals were withdrawn from the experiment on the 8th day of head injury. We studied paraffin sections of the left lung of rats. Using the Abcam kits (USA), an immunohistochemical study of the localization of endothelin -1 on sections of the left lung was carried out, the histochemical detection of calcium cations was performed using alizarin red C. Results. The morphofunctional characteristics of the lungs of rats with experimental traumatic brain injury were investigated. It was found that when the brain of experimental animals is damaged, lipid-associated lymphoid clusters appear in the root of the left lung of rats, and the content of endothelin-1 in cardiomyocytes of the pulmonary vein and epithelium of terminal bronchioles increases. A change in the histochemical characteristics of the localization of calcium cations in the cells and tissues of the left lung is revealed, which indicates a tendency towards the development of obstruction of terminal bronchioles and migration of macrophages into the parenchyma of the alveoli. Conclusion: Thus, with TBI, the mechanisms of humoral regulation of the respiratory system function significantly change. Histochemical study of endothelin 1 revealed that the expression in the lung tissues is calcium-dependent. receptor and mediator systems of cell membranes. These data are confirmed by staining the lungs with alizarin red C.


InterConf ◽  
2021 ◽  
pp. 970-978
Author(s):  
Z. Nizomov ◽  
M. Asozoda ◽  
A. Olimi ◽  
A. Karimzoda

The absorption of ultrasonic waves in the frequency range from 6 to 146 MHz in aqueous solutions of sodium acetate, sodium chloride and calcium has been studied. It was found that only in solutions of calcium cations and acetate anion present simultaneously, relaxation absorption of ultrasonic waves is observed. The experimental data obtained indicate that the observed relaxation absorption of ultrasound in the studied frequency range by an aqueous solution of calcium acetate is associated with the interaction of the acetate anion with the calcium cation in the solution.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 433
Author(s):  
Sara Trujillo ◽  
Melanie Seow ◽  
Aline Lueckgen ◽  
Manuel Salmeron-Sanchez ◽  
Amaia Cipitria

Alginate is a polysaccharide used extensively in biomedical applications due to its biocompatibility and suitability for hydrogel fabrication using mild reaction chemistries. Though alginate has commonly been crosslinked using divalent cations, covalent crosslinking chemistries have also been developed. Hydrogels with tuneable mechanical properties are required for many biomedical applications to mimic the stiffness of different tissues. Here, we present a strategy to engineer alginate hydrogels with tuneable mechanical properties by covalent crosslinking of a norbornene-modified alginate using ultraviolet (UV)-initiated thiol-ene chemistry. We also demonstrate that the system can be functionalised with cues such as full-length fibronectin and protease-degradable sequences. Finally, we take advantage of alginate’s ability to be crosslinked covalently and ionically to design dual crosslinked constructs enabling dynamic control of mechanical properties, with gels that undergo cycles of stiffening–softening by adding and quenching calcium cations. Overall, we present a versatile hydrogel with tuneable and dynamic mechanical properties, and incorporate cell-interactive features such as cell-mediated protease-induced degradability and full-length proteins, which may find applications in a variety of biomedical contexts.


2021 ◽  
Vol 34 ◽  
pp. 04008
Author(s):  
Galina Yakuba ◽  
Irina Mishchenko ◽  
Yuri Yakuba

The effectiveness of inorganic copper compounds on apple and plum trees under extreme weather conditions in 2018-2020 has been evaluated. Fungicides Koside 2000, VDG and Champ DP, VDG controlled apple scab by 98-99.6%, preparations Cuproxat, KS and Terpen C, KS blocked plum clotterosporiasis by 85.1-100%. The use of these fungicides did not have a negative effect on the biochemical composition of the fruit. Significant differences between the variants were found in the content of potassium and calcium cations, on the drain, in addition, in the content of sodium and magnesium cations. The possibility of biologization of protection technologies has been established: the use of the fungicide Champ DP, VDG on the apple tree, the replacement of Abiga-Peak, VS on the drain with preparations with lower consumption rates – Kuproksat, KS and Terpen C, KS. This ensures a reduction in the pesticide load on the environment, a decrease in the risk of resistance and the damaging effect of fungicides on trees weakened by stress.


Author(s):  
Е.Ю. Тупикина ◽  
С.Г. Ястребов

The paper presents results of quantum-chemical modelling of two types of molecular complexes of glycine with phosphine oxide H3PO interacting through a proton or a Ca2 + cation. It demonstrates that the formation of a glycine-Ca2 + - phosphine oxide complex is energetically more favourable than the origination of an aggregate assembling with a hydrogen bond. The results obtained allow us to hope for the use of free amino acids to reduce the concentration of calcium cations in areas damaged by calcifications.


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