The hydrogen bond energy of molecular complexes between a flotation reagent and coal’s organic mass is calculated for the first time. The electron density distribution in molecules of ...2-methyl-1,3-dioxane and 2-methyl-1,3-dioxa-2-silacyclohexane is determined. It is shown that the silicon atom in the molecule of 2-methyl-1,3-dioxa-2-silacyclohexane increases the electron density at oxygen atoms from −0.279 to −0.424 and −0.432 in positions 1 and 3 of the molecule, respectively. This increases the hydrogen bond energy of the reagent in molecular complexes with water and model compounds of the coal’s organic mass. In molecular complexes of 2-methyl-1,3-dioxa-2-silacyclohexane with model compounds of the coal’s organic mass, the hydrogen bond energy is considerably higher than in corresponding complexes of 2-methyl-1,3-dioxane. As a result, the adsorption of 2-methyl-1,3-dioxa-2-silacyclohexane on the coal surface is 35–45% greater than for 2-methyl-1,3-dioxane. Consequently, the coal grains become more hydrophobic, and their flotation is improved. With the same consumption of reagents, the use of 2-methyl-1,3-dioxa-2-silacyclo-hexane rather than 2-methyl-1,3-dioxane increases the concentrate yield and reduces the losses of the coal’s organic mass with the wastes. Analogous flotation properties of coal are found for other cyclic acetals and their silicon analogs. Experimental data confirm that the hydrogen bond energy in complexes between the flotation reagent and the coal’s organic mass may be used to assess its effectiveness.
The current investigation is focused on the development of composite membranes based on polymeric ionic liquids (PILs) containing imidazolium and pyridinium polycations with various counterions, ...including hexafluorophosphate, tetrafluoroborate, and bis(trifluoromethylsulfonyl)imide. A combination of spectroscopic methods was used to identify the synthesized PILs and characterize their interaction with carbon dioxide. The density and surface free energy of polymers were performed by wettability measurements, and the results are in good agreement with the permeability and selectivity obtained within the gas transport tests. It was shown that the membranes with a selective layer based on PILs exhibit relatively high permeability with COsub.2 and high ideal selectivity COsub.2/CHsub.4 and COsub.2/Nsub.2. Additionally, it was found that the type of an anion significantly affects the performance of the obtained membranes, with the most pronounced effect from bis-triflimide-based polymers, showing the highest permeability coefficient. These results provide valuable insights into the design and optimization of PIL-based membranes for natural and flue gas treatment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Background:
The prevalence of varicose veins of small pelvic veins in women of reproductive age varies widely – from 5.4 to 80 %, due to the low specificity and low sensitivity of clinical diagnostic ...techniques, and the absence of biomarkers that can be used to identify the formation and progression of varicose veins of small pelvic veins in women.
Aims:
To identify changes in the levels of parameters of the system “lipid peroxidation – antioxidant protection” with the development of varicose veins of the pelvis in women, as well as the possibility of their diagnostic use.
Materials and methods:
We examined 200 women with clinical signs of varicose veins of small pelvis. Control group included 30 women without any pathology of venous system. Treatment group included 137 women with varicose veins of small pelvis: with mild degree of severity – 39 women, with moderate degree of severity – 65 women, with severe degree of severity – 33 women. We performed comparative analysis of lipid peroxidation – antioxidant defense system in women with and without varicose veins of small pelvis taking into account the severity degrees of pathological process.
Results:
We obtained the most informative indices for lipid peroxidation – antioxidant defense processes in blood of women with varicose veins of small pelvis: concentration of diene conjugate (DC) for the mild degree of severity of pathological process, lipid hydroperoxide (LHP), DC and malonic dialdehyde (MDA) – for the moderate and severe degree of severity, and also changes in the activity of antioxidant enzymes with increase of the severity of the disease. Assessment of the level of catalase (Cat) and glutathione peroxidase (GP) showed their highest informative value at the mild degree of severity. Concentrations of glutathione reductase (GR), glutathione S-transferase (GST) and reduced glutathione (GSH) are more statistically significant markers for severe forms of pathological process.
Conclusions:
Our research showed the relevance and advisability of the studying the levels of lipid peroxidation – antioxidant defense indices in women with varicose veins of small pelvis. We registered the highest diagnostic value of DC, Cat and GP in the beginning of the disease and of LHP, DC, MDA, GR, GST and GSH – at severe forms of the pathological process. We obtained reference values for DC, MDA, Cat, SOD and GP concentration that can be considered as the predictors of the development of varicose veins of small pelvis.
Background.
Research in oncology assumes establishment and usage of xenograft animal models, meeting the requirements of humanity and rationality. Although praised as promising field of research, ...preclinical studies of low-molecular-weight inhibitors, antitumor monoclonal antibodies, vaccines, cellular therapy products, CAR-T cells entail continuous control of tumor growth dynamics. Luciferase detection of bioluminescence requires injection of a reporter substrate. However, injections not only are laborious, time-consuming and expensive, but are also stressful for animals. Thus, a vast variety of new visualization methods is employed, including proteins of the far-red spectrum.
Objective.
The study aimed to compare detection efficiency of tumor growth dynamics in mice models of cervical cancer, applying a commercially available line of fluorescent red protein derivatives of Katushka clade and
Renilla
luciferase, that is commonly used in
in vivo
studies
.
Design and methods.
Xenograft mice models were derived injecting modified HeLa cell line, that expresses fluorescent reporter proteins: Katushka, Katushka2S, TurboRFP, TurboFP650 and
Renilla
enzyme.
Results.
Spectral properties and emission wavelength of far-red fluorescent protein Katushka and Katushka2S outlines these markers within RFP derivatives lineage as outstanding instrument for
in vivo
tumor visualization.
Conclusion.
Detection of fluorescent far-red reporters Katushka and Katushka2S can be considered as a credible alternative to
Renilla
luciferase bioluminescence in experimental models
in vivo
on the part of immunotherapy research.
Microindentation of the proton exchange layers on X cut of lithium niobate single crystals was performed. The results were interpreted in the framework of the proportional specimen resistance model. ...It was found that proton exchange causes increase in the load-independent (“true”) hardness and decrease in the crystal elasticity. The elastic properties of proton exchange layers improve due to annealing while their load-independent hardness decreases. However, in all annealing conditions both hardness and elasticity cannot restore to the corresponding original values of the virgin lithium niobate.
►Proton exchange increases ‘true’ hardness of lithium niobate and decreases crystal elasticity. ► Annealing improves elasticity and decreases the ‘true’ hardness of proton-exchange layer. ► Hardness and elasticity are not restored to the values for virgin lithium niobate after annealing.
The measurements of open charm production was proposed as an important tool to investigate the properties of the hot and dense matter formed in nucleus-nucleus collisions as well as to provide the ...means for model independent interpretation of the existing data on J/ψ suppression. Recently, the experimental setup of the NA61/SHINE experiment was supplemented with a Vertex Detector which was motivated by the importance and the possibility of the first direct measurements of open charm meson production in heavy ion collisions at SPS energies. First test data taken in December 2016 on Pb+Pb collisions at 150A GeV/c allowed to validate the general concept of D0 meson detection via its D0 → π+ + K− decay channel and delivered a first indication of open charm production.
The physics motivation of open charm measurements at SPS energies, pilot results on open charm production, and finally, the future plans of open charm measurements in the NA61/SHINE experiment after LS2 are presented.
The NA61/SHINE collaboration studies at the CERN Super Proton Synchrotron (SPS) the onset of deconfinement in hadronic matter by the measurement of particle production in collisions of nuclei with ...various sizes at a set of energies covering the SPS energy range. This paper presents results on inclusive double-differential spectra and mean multiplicities of
π
-
mesons produced in the 5% most
central
7
Be +
9
Be collisions at beam momenta of 19
A
, 30
A
, 40
A
, 75
A
and 150
A
GeV
/
c
obtained by the so-called
h
-
method which does not require any particle identification. The shape of the transverse mass spectra differs from the shapes measured in
central
Pb + Pb collisions and inelastic
p+p
interactions. The normalized width of the rapidity distribution decreases with increasing collision energy and is in between the results for inelastic nucleon–nucleon and
central
Pb + Pb collisions. The mean multiplicity of pions per wounded nucleon in
central
7
Be +
9
Be collisions is close to that in
central
Pb + Pb collisions up to 75
A
GeV
/
c
. However, at the top SPS energy the result lies between those for nucleon–nucleon and Pb + Pb interactions. The results are discussed in the context of predictions for the onset of deconfinement at the CERN SPS collision energies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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