We report on a precision energy loss measurement and theoretical investigation of 100 keV/u helium ions in a hydrogen-discharge plasma. Collision processes of helium ions with protons, free ...electrons, and hydrogen atoms are ideally suited for benchmarking plasma stopping-power models. Energy loss results of our experiments are significantly higher than the predictions of traditional effective charge models. We obtained good agreement with our data by solving rate equations, where in addition to the ground state, also excited electronic configurations were considered for the projectile ions. Hence, we demonstrate that excited projectile states, resulting from collisions, leading to capture-, ionization-, and radiative-decay processes, play an important role in the stopping process in plasma.
The effect of copper doping of ZnSe:Fe crystals on the kinetics of luminescence of iron ions is investigated in this work. It has been discovered that doping with copper leads to a sharp decrease in ...the radiative recombination of iron ions at a temperature of 77 K. The obtained results are explained based on the model of nonradiative relaxation of iron ions due to Auger recombination with the participation of electrons in the conduction band.
Novel derivatives of Mycosidine (3,5-substituted thiazolidine-2,4-diones) are synthesized by Knoevenagel condensation and reactions of thiazolidines with chloroformates or halo-acetic acid esters. ...Furthermore, 5-Arylidene-2,4-thiazolidinediones and their 2-thioxo analogs containing halogen and hydroxy groups or di(benzyloxy) substituents in 5-benzylidene moiety are tested for antifungal activity in vitro. Some of the synthesized compounds exhibit high antifungal activity, both fungistatic and fungicidal, and lead to morphological changes in the
yeast cell wall. Based on the use of limited proteomic screening and toxicity analysis in mutants, we show that Mycosidine activity is associated with glucose transport. This suggests that this first-in-class antifungal drug has a novel mechanism of action that deserves further study.
The influenza NS1 protein is involved in suppression of the host immune response. Recently, there is growing evidence that prion-like protein aggregation plays an important role in cellular signaling ...and immune responses. In this work, we obtained a recombinant, influenza A NS1 protein and showed that it is able to form amyloid-like fibrils in vitro. Using proteolysis and subsequent mass spectrometry, we showed that regions resistant to protease hydrolysis highly differ between the native NS1 form (NS1-N) and fibrillar form (NS1-F); this indicates that significant structural changes occur during fibril formation. We also found a protein fragment that is capable of inducing the process of fibrillogenesis at 37 °C. The discovery of the ability of NS1 to form amyloid-like fibrils may be relevant to uncovering relationships between influenza A infection and modulation of the immune response.
•Recombinant NS1 protein is capable of forming amyloid-like fibrils.•Native form NS1 features a protease-resistant fragment from a.a. residues 1 to 78.•The fibrillar NS1 form's C-terminus is hydrolyzed by trypsin least of all.•During fibril formation, SDS-resistant non-native dimers form.•The NS1 Beta domain likely plays an important role in conformational transition.
Analytical dependences are constructed for a characteristic reinforced concrete element simulating inter-medium contact zones with simultaneously occurring processes of changing the long-term ...strength of concrete in time, taking into account the aging process of concrete and the process of neutralizing concrete with an aggressive environment. The proposed version of the calculation model of the long-term deformation of a corrosion-damaged composite reinforced concrete element in the zone of contact of two concretes makes it possible to study the deformed state of such structures in a plane stress state.
An emerging theme in modern astrophysics is the connection between astronomical observations and the underlying physical phenomena that drive our cosmos. Both the mechanisms responsible for the ...observed astrophysical phenomena and the tools used to probe such phenomena-the radiation and particle spectra we observe-have their roots in atomic, molecular, condensed matter, plasma, nuclear and particle physics. Chemistry is implicitly included in both molecular and condensed matter physics. This connection is the theme of the present report, which provides a broad, though non-exhaustive, overview of progress in our understanding of the cosmos resulting from recent theoretical and experimental advances in what is commonly called laboratory astrophysics. This work, carried out by a diverse community of laboratory astrophysicists, is increasingly important as astrophysics transitions into an era of precise measurement and high fidelity modeling.
A 3D model of the Earth’s crust for the continental margin of the Laptev Sea and the adjacent part of the Eurasian Basin was developed using the latest seismic and gravity data. The thickness of the ...consolidated part of the Earth’s crust in the study area is estimated at 7–11 km, which corresponds to a highly extended continental or oceanic crust. The formation of the basement and sedimentation in this area most likely began in the Late Jurassic. The southeastern part of the Eurasian Basin is separated from the rest of the basin by a dextral shear zone, the displacement along which during the Paleogene was more than 100 km.
Today, the global food security is one of the most pressing issues for humanity, and, according to Food and Agriculture Organisation (FAO), the increasing demand for food is likely to grow by 70% ...until 2050. In this current condition and future scenario, the agricultural production is a critical factor for global food security and for facing the food security challenge, with specific reference to many African countries, where a large quantities of rice are imported from other continents. According to FAO, to face the Africa’s inability to reach self-sufficiency in rice, it is urgent “to redress to stem the trend of over-reliance on imports and to satisfy the increasing demand for rice in areas where the potential of local production resources is exploited at very low levels” The present study was undertaken to design a new method for land evaluation based on soil quality indicators and remote sensing data, to assess and map soil suitability for rice crop. Results from the investigations, performed in some areas in the northern part of the Nile Delta, were compared with the most common approaches, two parametric (the square root, Storie methods) and two qualitative (ALES and MicrioLEIS) methods. From the qualitative point of view, the results showed that: (i) all the models provided partly similar outputs related to the soil quality assessments, so that the distinction using the crop productivity played an important role, and (ii) outputs from the soil suitability models were consistent with both the satellite Sentinel-2 Normalize Difference Vegetation Indices (NDVI) during the crop growth and the yield production. From the quantitative point of view, the comparison of the results from the diverse approaches well fit each other, and the model, herein proposed, provided the highest performance. As a whole, a significant increasing in R2 values was provided by the model herein proposed, with R2 equal to 0.92, followed by MicroLES, Storie, ALES and Root as R2 with value equal to 0.87, 0.86, 0.84 and 0.84, respectively, with increasing percentage in R2 equal to 5%, 6% and 8%, respectively. Furthermore, the proposed model illustrated that around (i) 44.44% of the total soils of the study area are highly suitable, (ii) 44% are moderately suitable, and (iii) approximately 11.56% are unsuitable for rice due to their adverse physical and chemical soil properties. The approach herein presented can be promptly re-applied in arid region and the quantitative results obtained can be used by decision makers and regional governments.
Recombinant human bone morphogenetic protein-2 with an additional s-tag domain (s-tag-BMP-2) synthesized in
E. coli
is characterized by higher solubility and activity than the protein without ...additional s-tag domain, which increases the yield during purification and simplifies protein introduction into the osteoplastic materials. The high osteoinductivity of the demineralized bone matrix with s-tag-BMP-2 was shown on the model of regeneration of cranial defects of a critical size in mice and on the model of implantation of porous titanium matrix into defects of femoral and tibial bones in rabbits.
Investigated as activators of radical-chain copolymerization of unsaturated polyester resins with methyl methacrylate acetylacetonates: cobalt (II) dihydrate, ferum (III), copper (II), chromium ...(III), nickel (II) dihydrate, zirconium (IV). Unsaturated polyester resins were obtained by polycondensation of maleic and phthalic anhydrides with ethylene glycol at 180 °C. Benzoyl peroxide was used as an initiator. Copolymerization was studied at temperatures from 30 to 60 °C by dilatometry using special collapsible dilatometers. The ratio of the unsaturated oligomer in the initial mixture to the monomer methylmethacrylate was 1:1. Determined the initial rate and temperature coefficient of the copolymerization reaction. A method for pretreatment of an activator solution in a monomer is proposed, which increases its efficiency in the process of redox radical copolymerization. After treatment, the content of Co2+ ions in the solution increases from 0.02 mol/l to 0.33 mol/l. The effect of both the nature of the activator and the modifier of polyester resins on the effective initial rate and temperature coefficient of the copolymerization reaction is shown. The following were used as modifiers of unsaturated oligoesters: 1,10-phenanthroline, diphenylamine, 1,2,3-benzotriazole. For comparison, methyl methacrylate was copolymerized with oligodiacrylates: triethyleneglycoldimethacrylate and bis-di- (triethyleneglycoldimethacrylate)phthalate. The following physical and mechanical characteristics of the obtained copolymers were determined: hardness, density, glass transition temperature. Initiating systems have been proposed for practical use in the copolymerization of unsaturated polyesters with vinyl monomers in a non-isothermal mode with the lowest risk of overheating. Mathematical calculations by the finite element method have been carried out and it has been shown that the use of the proposed methods makes it possible to increase the volume of the reaction mixture by several times in comparison with traditional systems.
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