Experimental investigation of the role of thyrocalcitonin in the prophylaxis of disturbances in the water-salt and mineral metabolism during a 30-day hypokinesia

The effect of thyrocalcitonin (TCT) injections on the metabolism of water and electrolytes in free-moving and immobilized chinchilla hares is described. Calcium excretion from immobilized animals was elevated, but normalized in those also receiving TCT injections. TCT also normalized water content and excretion rates

Influence of Anodizing by Electro-Chemical Oxidation on Fatigue and Wear Resistance of the EV31A-T6 Cast Magnesium Alloy

In the last decades, several anodizing processes for Mg alloys have been proposed to achieve a good wear and corrosion resistance combination. In particular, Electro-Chemical Oxidation (ECO) showed an improved dense and compact anodized layer compared to other anodizing processes carried out above the dielectric breakdown voltage, such as Plasma Electrolytic Oxidation (PEO). However, the influence of the ECO treatment on the tribological behavior and cyclic mechanical performance of Mg alloys has not been investigated yet. This paper reports on the influence of ECO on dry sliding behavior (vs. 100Cr6 bearing steel (block-on-ring contact geometry)) and rotating bending fatigue performance of the rare earth (RE)-containing Mg alloy EV31A-T6, comparing it with both untreated EV31A-T6 and PEO-treated EV31A-T6, used as benchmarks. The ECO-treated alloy showed improved tribological behavior (critical load for coating failure one order of magnitude higher and coefficient of friction 40% lower than for PEO) and fatigue strength (no decrease for ECO-treated samples compared to the untreated alloy, while PEO-treated samples induced a 15% decrease) due to the increased compactness and lower defectivity of the anodized layer, induced by the minimization of destructive arc discharges during coating growth. In addition, the ECO treatment significantly improved wear resistance compared to the untreated alloy, avoiding, at the same time, the decrease in fatigue strength, which typically occurs after PEO. Therefore, the ECO process can be applied to improve wear resistance without decreasing the fatigue strength of high-performance components

Tree stand assessment before and after windthrow based on open-access biodiversity data and aerial photography

The ground-based surveys of areas affected by storms might be difficult or even impossible because of the limited ability to move within the damaged area. Therefore, this work was aimed to estimate storm damage based on aerial photography and open biodiversity data available via the Internet. The study was carried out in the old-growth hemiboreal forests of the Kologrivsky Forest State Nature Reserve (Kostroma Region, Russia), which was affected by a catastrophic windthrow caused by a storm on 15.05.2021. The sampling area was 100 000 m2. We used our previous ground-survey studies and open-access biodiversity data available through the Global Biodiversity Information Facility for describing the forest stands composition before the catastrophic event. The aerial photography data were used for estimating tree stands damages after the windthrow. For remote data collecting, we used an unmanned aerial vehicle – quadrocopter DJI Phantom 4. Agisoft Metashape software was used for aerial photographs processing. The obtained photogrammetric digital elevation model (DEM) and orthophoto-mosaic were processed with QGIS software. Damaged areas were detected automatically based on the DEM. Individual fallen trees were visually detected using the orthophoto-mosaic. We found before the windthrow the study area was covered by old-growth stands developed naturally over a long time. The stand structure was multi-layered and uneven-aged. The ontogenetic spectra of late-successional tree species Picea abies (hereinafter – spruce) and Tilia cordata (hereinafter – linden) were normal. The old-growth stands were heterogeneous before the windthrow: the canopy closed multi-layered and uneven-aged stands, decaying spruce stands and areas where spruce completely fell out and the tree stand was absent. In addition, old-growth linden stands were present. According to the obtained results, the stand structure was critically changed caused by the windthrow. The DEM-processing results showed the windthrow strongly damaged 33.1% stands in the study area. Using the orthophoto-mosaic, we visually detected 759 fallen trees. Among them, 82.9% were associated with strongly-damaged areas. According to the DEM classification, the rest of the visually detected fallen trees were in non-damaged areas and canopy gaps established before the windthrow. The analysis showed that these were less damaged areas with survived stands or groups of trees after the storm. Thus, our results showed that it is necessary to use both the DEM and the orthophoto-mosaic for more accurate estimates. Our exploratory analysis of different tree stand damages found that apparently, spruce stands were more affected by the storm than linden stands. It is explained by the different wind resistance of spruce and linden and differences in regrowth density and species composition in these stands

Crossover critical behavior of Ga1-xMnxAs

The critical behavior of Ga1-xMnxAs in a close vicinity of the Curie temperature was experimentally studied by using the thermal diffusivity measurements. Taking into account that the inverse of the thermal diffusivity has the same critical behavior as the specific heat, the critical exponent {\alpha} for the samples investigated has been determined. With approaching close to the critical temperature, the crossover from the mean-field-like to the Ising-like critical behavior has been observed. From the crossover behavior the values of the Ginzburg number and the exchange interaction length in Ga1-xMnxAs with different concentrations of Mn were determined.Comment: 17 pages, 5 figure

The spall strength limit of matter at ultrahigh strain rates induced by laser shock waves

New results concerning the process of dynamic fracture of materials (spallation) by laser-induced shock waves are presented. The Nd-glass laser installations SIRIUS and KAMERTON were used for generation of shock waves with pressure up to 1 Mbar in plane Al alloy targets. The wavelengths of laser radiation were 1.06 and 0.53 μm, the target thickness was changed from 180 to 460 μm, and the laser radiation was focused in a spot with a 1-mm diameter on the surface of AMg6M aluminum alloy targets. Experimental results were compared to predictions of a numerical code which employed a real semiempirical wide-range equation of state. Strain rates in experiments were changed from 106 to 5 × 107 s−1. Two regimes of spallation were evidenced: the already known dynamic regime and a new quasi-stationary regime. An ultimate dynamic strength of 80 kbar was measured. Finally, experiments on targets with artificial spall layers were performed showing material hardening due to shock-wave compression

Chemical characterization and anti-inflammatory effect of rauvolfian, a pectic polysaccharide of Rauvolfia callus

The pectic polysaccharide named rauvolfian RS was obtained from the dried callus of Rauvolfia serpentina L. by extraction with 0.7% aqueous ammonium oxalate. Crude rauvolfian RS was purified using membrane ultrafiltration to yield the purified rauvolfian RSP in addition to glucan as admixture from the callus, with molecular weights 300 and 100-300 kD, respectively. A peroral pretreatment of mice with the crude and purified samples of rauvolfian (RS and RSP) was found to decrease colonic macroscopic scores, the total area of damage, and tissue myelope roxidase activity in colons as compared with a colitis group. RS and RSP were shown to stimulate production of mucus by colons of the colitis mice. RSP appeared to be an active constituent of the parent RS. The glucan failed to possess anti-inflammatory activity. © 2007 Pleiades Publishing, Ltd

Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4

Abstract An O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide isolated by the phenol-water extraction from the halotolerant soil bacteria Azospirillum halopraeferens type strain Au4. The polysaccharide was studied by sugar and methylation analyses, selective cleavages by Smith degradation and solvolysis with trifluoroacetic acid, one-and two-dimensional 1 H and 13 C NMR spectroscopy. The following masked repeating structure of the O-specific polysaccharide was established: →3)- where non-stoichiometric substituents, an O-methyl group (~45%) and a side-chain glucose residue (~65%), are shown in italics. 63

Capsular profiling of the Cronobacter genus and the association of specific Cronobacter sakazakii and C. malonaticus capsule types with neonatal meningitis and necrotizing enterocolitis

Background: Cronobacter sakazakii and C. malonaticus can cause serious diseases especially in infants where they are associated with rare but fatal neonatal infections such as meningitis and necrotising enterocolitis. Methods: This study used 104 whole genome sequenced strains, covering all seven species in the genus, to analyse capsule associated clusters of genes involved in the biosynthesis of the O-antigen, colanic acid, bacterial cellulose, enterobacterial common antigen (ECA), and a previously uncharacterised K-antigen. Results: Phylogeny of the gnd and galF genes flanking the O-antigen region enabled the defining of 38 subgroups which are potential serotypes. Two variants of the colanic acid synthesis gene cluster (CA1 and CA2) were found which differed with the absence of galE in CA2. Cellulose (bcs genes) were present in all species, but were absent in C. sakazakii sequence type (ST) 13 and clonal complex (CC) 100 strains. The ECA locus was found in all strains. The K-antigen capsular polysaccharide Region 1 (kpsEDCS) and Region 3 (kpsMT) genes were found in all Cronobacter strains. The highly variable Region 2 genes were assigned to 2 homology groups (K1 and K2). C. sakazakii and C. malonaticus isolates with capsular type [K2:CA2:Cell+] were associated with neonatal meningitis and necrotizing enterocolitis. Other capsular types were less associated with clinical infections. Conclusion: This study proposes a new capsular typing scheme which identifies a possible important virulence trait associated with severe neonatal infections. The various capsular polysaccharide structures warrant further investigation as they could be relevant to macrophage survival, desiccation resistance, environmental survival, and biofilm formation in the hospital environment, including neonatal enteral feeding tubes

Data on 30-year stand dynamics in an old-growth broad-leaved forest in the Kaluzhskie Zaseki State Nature Reserve, Russia

The article provides primary data on repeated tree measurements collected during two censuses on a permanent sampling plot (440 m × 200 m) established in the old-growth polydominant broad-leaved forest in the Kaluzhskie Zaseki State Nature Reserve (centre of European Russia). The time span between the inventories was 30 years, and a total of 11 578 individuals of ten tree, one shrub species, and several undefined tree species of three known genera were registered. During the surveys, tree identity, stem diameter at breast height (DBH) of 1.3 m, and life status (alive or dead) were recorded for every tree individual with DBH ≥ 5 cm. Additional attributes were determined for some individuals. Field data were digitised and compiled into the PostgreSQL database. An accurate data quality assessment, validation, and cleaning (with documentation of changes) have been performed before data standardisation according to the Darwin Core standard. Standardised data were published through the GBIF repository. From 1986 to 1988, 9811 individuals were recorded within the initial census, including 3920 Corylus avellana individual shrubs. Corylus avellana shrubs were recorded without measuring DBH. From 2016 to 2018, 7658 stems were recorded in the recensus, including 3090 living trees marked during the initial census, and 1641 other living trees reaching the DBH of at least 5 cm. Corylus avellana was not included in the recensus. Thus, over 30 years, about 65% of living tree individuals have survived, but the total number of living trees has not changed considerably. The mean diameter of shade-intolerant tree species (Quercus robur, Fraxinus excelsior, Populus tremula, and Betula spp.) has increased the most remarkably during 30 years. For these species, the increase in average diameter, along with the decrease in numbers, is associated with the death of young trees, presumably due to low illumination under the canopy. Contrastingly, shade-tolerant tree species (Ulmus glabra, Tilia cordata, Acer platanoides) increased in number, while their mean diameter increased slightly or even decreased, that evidences the successful regeneration of these species under the canopy. These data are relevant for investigating forest ecology questions at spatiotemporal scales as a model of natural succession

Genetic diversity of the Aporrectodea caliginosa complex in Russia

Earthworms of the Aporrectodea caliginosa species complex are abundant in many anthropogenic and natural habitats and often predominate in earthworm communities. In Russia, there are two subspecies of the complex, A. c. caliginosa and A. c. trapezoides; Aporrectodea longa was also recently mentioned as a putative member of the complex. In this study, we made an attempt to review available data on the species complex studied based on our collection from Russia, Belarus, and Kazakhstan. The subspecies A. c. caliginosa is represented in Russia by two genetic lineages, 2 and 3, the former being the prevalent (about 73 % of the total sample). Additionally, these lineages have different distributions: while lineage 2 was found in almost all locations studied, lineage 3 was detected only in a few samples from the periphery of the region studied. The genetic diversity of lineage 2 significantly exceeded that of lineage 3, and its estimated divergence time was almost three times as high. A subset of individuals with pigmentation characteristic of A. c. caliginosa contained cox1 haplotypes of A. c. trapezoides; analysis of nuclear gene sequences confirmed this diagnosis. Thus, pigmentation intensity in this subspecies was demonstrated to vary to a significant degree. In addition, we analyzed two A. longa individuals from West Siberia and the Urals; their cox1 sequences were identical to those from the lineage 1 of this species from the north of Western Europe. These are the first reports of A. c. trapezoides and A. longa from West Siberia. On the whole, both genetic diversity and abundance was shown to decrease in the following series: A. c. caliginosa lineage 2 – A. c. caliginosa lineage 3 – A. c. trapezoides and A. longa