The two lyotropic liquid crystalline media based on n-alkyl-poly (ethylene) glycols (C
8
E
5
and C
12
E
5
) and n-octanol for partial alignment of organic molecules and measured residual constants of ...dipole-dipole interaction between magnetic nuclei were studied. The paper presents the results of NMR studies of lyotropic properties of considered liquid crystalline media, and the boundaries (diagrams) of the existence of ordered lamellar phases (component concentrations, solution temperature) were determined.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The algorithm for the formation of the stiffness matrix of a four-sided finite element, which is a fragment of an ellipsoidal shell, the middle surface of which was represented by two variants of ...parametrization, is presented. In the first variant of parametrization of the middle surface of the ellipsoidal shell, the axial coordinate and the angle measured from the applicate axis to the radius vector of the cross-section of the shell are used. In the second version of the representation of the middle surface, the ellipse parameter of the cross section of the ellipsoidal shell was used instead of the angle. The components of the displacement vector and their first derivatives were taken as nodal unknowns of the four-sided finite element. The approximation of the required quantities was carried out in a vector formulation using Hermite polynomials of the third degree. The approximating relations for individual components were obtained using matrix expressions between the basis vectors of the nodal points of a finite element and the basis vectors of its arbitrary point. On the example of calculation of the elliptical cylinder the advantage of the second variant of parametrization of the middle surface of the ellipsoidal shell is shown, as well as the efficiency of the vector formulation of obtaining approximating expressions of the required quantities by the finite element method in curvilinear coordinate systems is demonstrated.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•The molecular interaction of several fenamates with POPC has been explained by various reliable NMR methods.•For fenamates were shown to penetrate the lipid membrane and are dynamically distributed ...within the bilayer.•The average location of molecule of fenamate into membrane in the lipid-water interface was estimated.•The binding of tolfenamic and mefenamic acid increases lipid chain order.•The flufenamic acid did not influence the lipid packing in POPC membranes.
Fenamates are nonsteroidal anti-inflammatory drugs (NSAID), usually prescribed to treat pain and inflammation and, like other NSAIDs, to inhibit cyclooxygenases. They have also been proposed to show anti-epileptic and neuroprotective effects. In the current work, the interaction of several fenamates with phospholipid membranes was studied using various NMR techniques. One of the most important properties of membranes that influences the function and localization of proteins is their fluidity. Changes in membrane fluidity can also affect a drug’s ability to bind to and permeate through the membrane, which influences its efficacy. We studied the interaction of several fenamates with zwitterionic palmitoyloleoylphosphatidylcholine (POPC) membranes. Based on 1H NMR-induced chemical shift data and quantitative analysis of 1H MAS NOESY cross-relaxation rates, three fenamates (mefenamic, flufenamic and tolfenamic acid) were shown to penetrate the lipid membrane and are dynamically distributed within the bilayer. The average position of each drug in the lipid-water interface was also estimated from these measurements. 2H NMR data showed that binding of tolfenamic and mefenamic acid increases lipid chain order, while flufenamic acid slightly decreased lipid chain order in the lower segments of POPC membranes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Objective
To determine if ingestion of lycosome-formulated dark chocolate (DC) containing astaxanthin (ASTX) improves bioavailability of ASTX and affects markers of hypoxia and oxidative stress in ...aging individuals.
Design
Randomized, blinded, four-arm, prospective study.
Settings
Lycotec Ltd, Cambridge, United Kingdom and Institute of Cardiology, Saratov, Russian Federation.
Participants
32 healthy individuals aged 60–70 years with confirmed signs of oxidative stress (increased serum levels of oxidized LDL and malonic dialdehyde) randomized into four study groups (8 volunteers each).
Intervention
Volunteers of first group were given orally 10 gr of dark chocolate (DC). Individuals from the second group received 7 mg of astaxanthin (ASTX). Third group of volunteers was supplemented with 10 gr of DC and 7 mg of ASTX ingested simultaneously as two separate formulations. Last group of the individuals was given 10 gr of a lycosomal formulation of DC containing 7 mg of co-crystalized ASTX (L-DC-ASTX), a newly developed highly bioavailable nutraceutical composition of DC containing 2 groups of antioxidants (cocoa flavanols and ASTX). All formulations were given orally, once daily for a month.
Measurements
Serum ASTX was measured by high-performance liquid chromatography. Nitric oxide, malonic dialdehyde and oxidized LDL were quantified spectrophotometrically. Oxygenation parameters were evaluated by near-infrared spectroscopy.
Results
One month ingestion of singular formulation of ASTX lead to a 20 fold buildup in serum ASTX level whereas the 4 week ingestion of L-DC-ASTX formulation was accompanied by more prominent accumulation of ASTX in serum (a 40 fold increase over the basal values) at the same daily dose of ASTX. Both antioxidants taken separately decreased serum levels of oxidized LDL and malonic dialdehyde. However effect of L-DC-ASTX formulation was more prominent. ASTX ingested alone caused a borderline increase (p=0.054) in serum nitric oxide (NO) levels, whereas DC ingestion lead to small but statistically significant increase in serum NO concentration. Higher values of NO level were seen after co-ingestion of DC and ASTX, especially in case of L-DC-ASTX formulation suggesting additive/synergistic effects of DC and ASTX on nitric oxide production. These changes were in agreement with the increase in plasma oxygen transport and tissue oxygen saturation seen in the volunteers supplemented with L-DC-ASTX formulation.
Conclusion
The nutraceutical formulation of DC and ASTX with an enhanced bioavailability of ASTX can be efficiently used for the correction of oxidative status in aging individuals.
The nucleophilic addition reactions of tertiary phosphines and unsaturated carboxylic acids have led to the formation of mono- and dicarboxylate phosphabetaines containing an asymmetric carbon atom. ...The data of 1D and 2D NMR spectroscopy have revealed the presence of diastereotopic geminal protons of the CH
2
group adjacent to the chiral center in the obtained compounds. The values of spin-spin coupling constants of the vicinal hydrogen atoms have coincided with the dihedral angles values (X-ray diffraction analysis data).
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The NA61/SHINE experiment at the CERN SPS has recently extended its program for the energy scan with Pb ions. In the past, the NA49 experiment, which preceded the NA61/SHINE, has also recorded data ...for Pb–Pb collisions at different energies. Together, the two experiments cover wide range of collision energies in the beam momentum range of 13–150
A
GeV/
provided by CERN SPS, which has a significant overlap with the ongoing second phase of the beam energy scan program (BES-II) at RHIC. The directed and elliptic flow relative to the projectile spectator plane are measured with the new NA61/SHINE data for Pb–Pb collisions at 13 and 30
A
GeV/
and revised existing NA49 data at 40
A
GeV. New results extend the existing world data available from the previous NA49 measurements and ongoing BES-II and fixed-target programs at STAR. The developed analysis techniques are also relevant for measurements at the future CBM experiment at FAIR and the MPD experiment at NICA.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The etherification reaction of ortho-phosphoric acid (OPA) with polyoxypropylene glycol in the presence of tertiary amines was studied. The reaction conditions promoting the catalytic activity of ...triethanolamine (TEOA) and triethylamine (TEA) in the low-temperature etherification of OPA were established. The catalytic activity of TEOA and TEA in the etherification reaction of phosphoric acid is explained by the hydrophobic-hydrophilic interactions of TEA with PPG, leading, as a result of collective interactions, to a specific orientation of polyoxypropylene chains around the tertiary amine. When using triethylamine, complete etherification of OPA occurs, accompanied by the formation of branched OPA ethers terminated by hydroxyl groups and even the formation of polyphosphate structures. When triethanolamine is used as a catalyst, incomplete etherification of OPA with polyoxypropylene glycol occurs and as a result, part of the phosphate anions remain unreacted in the composition of the resulting aminoethers of ortho-phosphoric acid (AEPA). In this case, the hydroxyl groups of triethanolamine are completely involved in the OPA etherification reaction, but the catalytic activity of the tertiary amine weakens due to a decrease in its availability in the branched structure of AEPA. The kinetics of the etherification reaction of OPA by polyoxypropylene glycol catalyzed by TEOA and TEA were studied. It was shown that triethanolamine occupies a central position in the AEPA structure. The physico-mechanical and thermomechanical properties of polyurethane ionomer films obtained on the basis of AEPA synthesized in a wide temperature range were studied.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Paramagnetic gadolinium ions are used as one of the possible contrast agents for magnetic resonance imaging. Contrast agents interact with living cells. An interesting task is to determine how the ...interaction between the contrast medium and the living cell occurs. The paper presents the results of a study of the interaction between paramagnetic gadolinium ions and membrane models using micelles based on dodecylphosphocholine and reverse micelles based on dioctyl sulfosuccinate sodium salt by nuclear magnetic resonance spectroscopy. From the spectra analysis, it was revealed that the interaction exists for both types of micelles. It is also suggested at a qualitative level the possible site of interaction between gadolinium ions and the hydrophilic part of the bipolar molecules that form micelles.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
PG-1 adopts a dimeric structure in dodecylphosphocholine (DPC) micelles, and a channel is formed by the association of several dimers but the molecular mechanisms of the membrane damage by ...non-α-helical peptides are still unknown. The formation of the PG-1 dimer is important for pore formation in the lipid bilayer, since the dimer can be regarded as the primary unit for assembly into the ordered aggregates. It was supposed that only 12 residues (RGGRL-CYCRR-RFCVC-V) are needed to endow protegrin molecules with strong antibacterial activity and that at least four additional residues are needed to add potent antifungal properties. Thus, the 16-residue protegrin (PG-2) represents the minimal structure needed for broad-spectrum antimicrobial activity encompassing bacteria and fungi. As the peptide conformation and peptide-to-membrane binding properties are very sensitive to single amino acid substitutions, the solution structure of PG-2 in solution and in a membrane mimicking environment are crucial. In order to find evidence if the oligomerization state of PG-1 in a lipid environment will be the same or not for another protegrins, we investigate in the present work the PG-2 NMR solution structure in the presence of perdeuterated DPC micelles. The NMR study reported in the present work indicates that PG-2 form a well-defined structure (PDB: 2MUH) composed of a two-stranded antiparallel β-sheet when it binds to DPC micelles.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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