We compared the immunogenicity of recombinant
S. pneumoniae
pneumolysin (rPly) when administered with and without Al(OH)
3
adjuvant, and evaluated the protective properties of recombinant protein in ...the active defense experiment. It was shown that double immunization with rPly+Al(OH)
3
increases the levels of IgG antibodies in comparison with the control (
p
<0.01), while triple immunization results in a more significant increase in IgG antibody levels (
p
<0.001). Double immunization with rPly without Al(OH)
3
does not induce a significant increase in antibody levels in comparison with the control, while triple immunization results in a slight but significant increase in antibody levels (
p
<0.05). The active defense test proved the protective activity of rPly against
S. pneumoniae
serotype 3 at intranasal infection.
High-resolution electron backscatter diffraction (EBSD) was used to examine the grain structure in long rods of ultrafine-grain (UFG) commercial-purity titanium produced for medical implants. The UFG ...material was obtained by equal channel angular pressing (ECAP) using a Conform scheme followed by rod drawing. The microstructure was found to be bimodal consisting of relatively coarse elongated grains containing well-developed substructure and ultrafine grains. The mean grain size was ~0.3μm, and the fraction of high-angle boundaries was ~45%. The material had a strong <101¯0>-fiber texture. An analysis of the microstructure–properties relationship showed that the increase in material strength developed during severe plastic deformation resulted from grain refinement and substructure evolution in comparable measure.
Abstract
The article studies the fatures of stress distribution around the mining excavations under different tectonic loads on the case study of the Zhdanovskoe copper-nickel ore deposit, Murmansk ...region, Russia. The deposit is located in the Arctic zone on the Russia-Norway state boundary and is excavated by the Severny underground mine using simultaneously the sublevel caving and the open stoping methods. The combination of these mining methods in the same area affects the geomechanical conditions; moreover, the highest level of stresses is identified between the opposing excavation fronts. The deepening of mining increases the geodynamic risks caused by the stress state in the rock mass. In this regard, the study of the Zhdanovskoe deposit rock mass stress state and its transformation due to the mining progress is urgent. To address the issues a numerical geomechanical 3D model was created. To specify the correct boundary conditions, the results of the in-situ measurements were compared to visual observation results. To achieve the most accurate result, the direction and ratio of the tectonic loads were varied and the results were analyzed. The authors have analysed the modelling results in the form of the stresses and deformations distribution in the area around the excavations under different directions of tectonic loads. Based on this analysis, the authors have substantiated a relevant variant of direction of tectonic forces relatively the ore body strike. The results have been applied to forecast the changes in perspective stress-strain state during the mining progress.
Although photophysical properties of Radachlorin photosensitizer (PS) were extensively studied in solutions and cells, no data is available on variations of its characteristics upon binding to serum ...albumins, which are major transporters in blood and nutrients in cell culture media.
The primary objective of this study was to analyze changes in photophysical properties of Radachlorin molecules upon their binding to human and bovine serum albumins at different microenvironment properties.
Experiments were performed using time-resolved fluorescence spectroscopy and fluorescence recovery after photobleaching. Variations in fluorescence spectra and lifetime, fluorescence anisotropy, rotational and translational diffusion of PS molecules upon binding to albumins were studied in normal, basic and acidic conditions and at different concentrations of albumin and PS molecules.
Radachlorin molecules effectively bind to both types of serum albumins, which causes changes in photophysical properties of the PS. A minor red shift of the fluorescence spectrum, an increase in fluorescence lifetime and anisotropy and substantial decrease of translational and rotational mobility of PS molecules were observed upon their binding to albumins. The analysis of rotational diffusion time provided robust evaluation of the bound fraction of PS molecules. Both the highly acidic microenvironment and increase in alcohol concentration above 40% resulted in detachment of PS molecules from albumins. Photophysical properties of Radachlorin in complexes with BSA and HSA were found to be slightly different.
Binding of Radachlorin photosensitizer to either BSA or HSA affects significantly its photophysical properties, which may also vary with microenvironment acidity and alcohol concentration.
The paper studies experimentally and theoretically the interference structure of the low-frequency spatial amplitude and phase responses of the scalar field and three projections of the vibrational ...velocity vector formed by tone signals from towed omnidirectional acoustic sources in zones near the interference maxima and minima of the sound pressure. The experimental dependences of these field characteristics on the distance obtained by four-component vector-scalar receivers when the sources are towed are compared with the calculated ones within the Pekeris model and waveguide model with a three-layer seafloor, the parameters of which were calculated based on acoustic calibration of the operations area. Satisfactory agreement was established between the amplitude and phase responses of the field, calculated by acoustic calibration and measured experimentally. It is shown that in the zones of maxima, a slow change in the angle of arrival is observed and the phase gradients are “smooth”, while in the zones of the minimum, sharp jumps in the amplitudes and phases form in the horizontal and vertical planes, leading for deep minima to the formation of circulations: local vortices around the poles. Numerical analysis of the fine structure of the sound pressure and vibrational velocity projections in the acoustic vortex zone is carried out, and hodographs of the vibrational velocity and phase gradients of the sound pressure are calculated, confirming the formation of vortices in the vertical plane in the zone of the poles.
A methodology providing noninvasive monitoring and evaluation of the effect of photodynamic treatment on live cells in vitro is presented. Variations in morphological characteristics of cells in the ...course and after treatment are recorded by means of digital holographic microscopy. High-precision measurements of phase shift gained by probe radiation in HeLa and human endometrial mesenchymal stem cell cultures demonstrate for the first time changes of their volume occurred in response to treatment.
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•Radachlorin fluorescence lifetime and quantum yield vary with microenvironment pH.•Radachlorin fluorescence lifetimes differ in different cell compartments.•Radachlorin localizes ...predominantly in lysosomes.•Changes of Radachlorin fluorescence lifetimes with pH are reversible.
Intracellular localization of photosensitizer molecules is influential on cell death pathway at photodynamic treatment and is thus an important aspect in achieving enhanced efficacy of photodynamic therapy. In this paper we performed thorough studies of the distribution of Radachlorin photosensitizer in three established cell lines: HeLa, A549, and 3T3 with fluorescence lifetime imaging microscopy through the analysis of lifetime distributions. Experiments carried out in Radachlorin solutions in phosphate buffered saline revealed the pronounced dependence of the fluorescence quantum yield and lifetime on solution pH. This finding was used for analysis of lifetime images of living cells and their phasor plot representations and allowed us to suggest that Radachlorin localized predominantly in lysosomes, known to have acidic pH values. Experiments on co-localization of Radachlorin fluorescence lifetimes and LysoTracker fluorescence intensity supported this suggestion. The results obtained show that the inhomogeneity of fluorescence quantum yield within a cell can be significant due to lower pH values in lysosomes than in other intracellular compartments. This finding suggests that the actual amount of accumulated Radachlorin can be underestimated if being evaluated solely by comparison of fluorescence intensities.
The paper presents a novel algorithm based on digital holographic interferometry and being promising for evaluation of phase variations from highly noisy or modulated by speckle-structures digital ...holograms. The suggested algorithm simulates an interferogram in finite width fringes, by analogy with classical double exposure holographic interferometry. Thus obtained interferogram is then processed as a digital hologram. The advantages of the suggested approach are demonstrated in numerical experiments on calculations of differences in phase distributions of wave fronts modulated by speckle structure, as well as in a physical experiment on the analysis of laser-induced heating dynamics of an aqueous solution of a photosensitizer. It is shown that owing to the inherent capability of the approach to perform adjustable smoothing of compared wave fronts, the resulting difference undergoes noise filtering. This capability of adjustable smoothing may be used to minimize losses in spatial resolution. Since the method allows to vary an observation angle of compared wave fields, an opportunity to compensate misalignment of optical axes of these wave fronts arises. This feature can be required, for example, when using two different setups in comparative digital holography or for compensation of recording system displacements during a set of exposures in studies of dynamic processes.
We present a thorough experimental investigation of fluorescence properties of Radachlorin photosensitizer in solutions of different acidity, viscosity and polarity. Experiments were performed using ...time-resolved fluorescence lifetime imaging and time-resolved analysis of polarized fluorescence. Variations of solution acidity resulted in considerable changes of Radachlorin fluorescence quantum yield and lifetime in the pH range from 4 to 7, but did not affect the rotational diffusion time, and almost did not change the quantum yield and characteristic times of singlet oxygen phosphorescence. Variations of solution polarity and viscosity were achieved by changing ethanol or methanol fraction in aqueous solution. The decrease of solution polarity resulted in nonlinear rise of Radachlorin fluorescence quantum yield and lifetime up to alcohol concentration of 50%–65%, as well as in considerable rise of singlet oxygen quantum yield and significant changes in characteristic times of its phosphorescence. Variations of solution viscosity resulted in changes of rotational diffusion time of Radachlorin molecules, which appeared to be in perfect correlation with methanol solution viscosity. Good correspondence with ethanol solution viscosity was observed only up to 50% alcohol fraction. Deviations of rotational diffusion time of Radachlorin molecules from direct proportionality with solution viscosity at higher ethanol concentrations were suggested to be due to different solvation conditions. The data obtained can give important reference points for analysis of microenvironment of Radachlorin molecules, their intracellular localization and performance in singlet oxygen generation.
Display omitted
•Radachlorin fluorescence lifetime and quantum yield vary significantly with pH.•Radachlorin fluorescence quantum yield and lifetime nonlinearly depend on polarity.•Decrease of solution polarity causes rise of singlet oxygen quantum yield.•Rotational diffusion time of Radachlorin varies with solution viscosity.•Two-photon excitation provides high anisotropy of Radachlorin fluorescence.
Ruddlesden-Popper-type La2NiO4+δ oxide is considered as a potential cathode for solid oxide fuel cell applications. In this work, the tailoring possibility of the cathode material properties by ...doping with a small amount of Co has been investigated. The initial powders were synthesized by the self-propagating high-temperature synthesis method. The sintering kinetics, thermal expansion, electrical conductivity, catalytic activity of La2Ni1-xCoxO4+δ (0 ≤ x ≤ 0.3) as well as their interaction with Zr0.84Y0.16O2-δ (YSZ) and Ce0.73Gd0.27O2-δ (GDC) electrolytes have been studied. It was shown that the coefficient of thermal expansion of the investigated compositions increases with increasing the Co content. The Co doping leads to decreasing of La2Ni1-xCoxO4+δ conductivity in the temperature range below 600°С, whereas at higher temperatures, compositions with x = 0.2 and 0.3 have higher conductivity than La2NiO4. The polarization resistance of the cathodes in contact with YSZ increases with increasing the Co content. However, in contact with GDC the La2Ni0.8Co0.2O4+δ composition has the lowest polarization resistance of 0.4 Ω cm2 (at 800 °C), which is 1.5 times less than that of La2NiO4+δ. Therefore, it was concluded that doping with the appropriate amount of Co could further improve the properties of lanthanum nickelate cathode.
•CTE of La2Ni1-xCoxO4 increases with increasing Co content.•Below 600 °C the conductivity of La2Ni1-xCoxO4 decreases with increasing Co content.•Above 600°С the La2Ni1-xCoxO4 at x = 0.2, 0.3 have higher conductivity than La2NiO4.•The polarization resistance of La2Ni1-xCoxO4 – YSZ increases with increasing Co.•The lowest polarization resistance of La2Ni1-xCoxO4 – GDC is observed at x = 0.2.
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