Galactic cosmic rays consist of protons, electrons and ions, most of which are believed to be accelerated to relativistic speeds in supernova remnants. All components of the cosmic rays show an ...intensity that decreases as a power law with increasing energy (for example as E-2.7). Electrons in particular lose energy rapidly through synchrotron and inverse Compton processes, resulting in a relatively short lifetime (about 105 years) and a rapidly falling intensity, which raises the possibility of seeing the contribution from individual nearby sources (less than one kiloparsec away). Here we report an excess of galactic cosmic-ray electrons at energies of ∼300-800 GeV, which indicates a nearby source of energetic electrons. Such a source could be an unseen astrophysical object (such as a pulsar or micro-quasar) that accelerates electrons to those energies, or the electrons could arise from the annihilation of dark matter particles (such as a Kaluza-Klein particle with a mass of about 620 GeV).
The influence of the surface modification of multi-walled carbon nanotubes (MWCNT) with nitrogen-containing compounds on the performance of 40 wt% Pt/MWCNT catalysts in the oxygen electroreduction ...reaction (ORR) was investigated using a rotating disk electrode (RDE) at 10–35 °C in 0.1 M HClO
4
as electrolyte in electrochemical cell, and in a hydrogen–oxygen polymer electrolyte membrane fuel cell (PEMFC) at 82 °C. The catalysts were characterized by low-temperature nitrogen adsorption, XPS, TEM, gas-phase CO titration, electrooxidation of the adsorbed CO monolayer, and cyclic voltammetry. It was shown that the modification of MWCNT with melamine–formaldehyde resin leads to the surface nitrogen concentration up to 8.3 at.% (CNT-MF sample). The 40 wt% Pt/CNT-MF catalyst with 0.1 mg cm
−2
Pt loading on the cathode showed a good performance in PEMFC (~ 0.61 W cm
−2
) and a high utilization ratio (0.84) of Pt in membrane electrode assembly as compared to Pt/CNT catalyst (~ 0.37 W cm
−2
and utilization of 0.29). The higher power density of nitrogen-modified catalysts was ascribed to a higher utilization of Pt in the electrode layer.
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•Xylogalacturonan-enriched pectin is water-soluble pectin from the baobab fruit pulp.•Starch is co-extracted with pectin at long extraction times and temperatures.•Part of α-GalpA ...residues are 3-O-substituted with terminal β-Xylp residues.•Xylogalacturonan possesses an antidepressant-like effect.
The low methyl-esterified and acetylated xylogalacturonan (DM 20 %, DA 2 %, Mw ∼ 58 kDa) was isolated by water extraction for 4 h × 2 at 50 °C (yield 23 %) from the pulp of baobab fruit (Adansonia digitata L.). Subsequent tightening of the conditions for water extraction by mean increasing the temperature to 70 °C and time to 12 h led to the co-extraction of small amounts of starch components and RG I with xylogalacturonan. Structural analysis (DEAE-cellulose ion-exchange chromatography, HPSEC, monosaccharide analysis, NMR spectroscopy) revealed that about 12 mol. % of 1,4-linked α-GalpA residues were substituted by single β-Xylp residues at the O-3 position. The xylogalacturonan was found to possess an antidepressant-like effect in mice. The study offers using the baobab fruit as a rich source of soluble dietary fiber – water-soluble pectin with beneficial physiological effect.
At the A. E. Favorsky Irkutsk Institute of Chemistry, a series of silatrane-sulfonamide hybrids
1a-d
and
2a-d
was synthesized. The antibacterial activity of
1a, 1b, 1d
,
2a
, and
2b
against test ...strains of bacteria
Yersinia pestis
EV NIIEG,
Yersinia enterocolitica
628/1,
Listeria monocytogenes
766, and
Starhylococcus aureus
ATCC 6538-P (FDA 209-Р) was evaluated. The minimum inhibitory concentration for silatrane-sulfonamide hybrids was 100-200 mg/liter. Silatrane-sulfonamide hybrid
1d
was the most active against all tested strains: minimum inhibitory concentration 100 mg/liter. Exposure to silatrane-sulfonamide hybrids in a doses of 100-200 mg/liter inhibited culture growth by 50-75%.
A pilot post-mortem study identifies a strong correlation between the attenuation coefficient estimated from the OCT data and some morphological features of the sample, namely the number of nuclei in ...the field of view of the histological image and the fiber structural parameter introduced in the study to quantify the difference in the myelinated fibers arrangements. The morphological features were identified from the histopathological images of the sample taken from the same locations as the OCT images and stained with the immunohistochemical (IHC) staining specific to the myelin. It was shown that the linear regression of the IHC quantitative characteristics allows adequate prediction of the attenuation coefficient of the sample. This discovery opens the opportunity for the usage of the OCT as a neuronavigation tool.
Naturally circulating antibodies could dramatically change the activity of immunogens. In some cases, cross-interference between antibodies led to the loss of their opsonizing ability. Therefore, the ...study of antibody repertoire in blood sera of healthy donors is helpful for the development of vaccines and diagnostic kits. Levels of antibodies to fragments of biologically significant glucosamine and galactosamine polysaccharides and their
N
-acetylated derivatives were first studied in blood sera of 34 healthy donors using six biotinylated carbohydrate ligands. The highest titer of antibodies was found to poly-β-(1→6)-
N
-acetylglucosamine (PNAG), including its fully de-
N
-acetylated fragment. High antibody titers to the galactosaminoglycan (GG) fragments were also detected. For both PNAG and GG, the level of antibodies to
N
-acetylated ligands was higher than to the ligands with free amino groups. A correlation between the antibody titers for the respective
N
-acetylated and
N
-deacetylated forms was observed, which may suggest a cross interaction. No significant amounts of the antibodies to the chitooligosaccharides were detected. The results obtained will help to rationally plan further immunological studies aimed at the development of new vaccines and diagnostic kits.
The fine structure of echiurid blood vessels in the proboscis is known in detail, but the circulatory system of the trunk is still understood mainly at the level of general anatomy. The trunk ...circulatory system was studied in
Bonellia viridis
females, and specialized podocytes were found to form the walls of the ring vessel and the anterior part of the ventral vessel. Podocytes were for the first time described in the echiurid circulatory system. Podocytes of
B. viridis
displayed a typical cell architecture, which is known for other bilaterians. A podocyte consists of a cell body; primary processes; and pedicels, which extend from the primary processes and are interconnected via specialized slit diaphragms. The presence of podocytes indicates that the ventral and ring vessels act as ultrafiltration sites, where the plasma is filtered through the basal lamina into the body cavity.
The study of the anatomy and fine structure of Echiura is of great importance for understanding the biology of these animals, which lead a secretive life and dominate in various benthic communities. ...The first data on the organization of the siphonal part of the midgut of female
Bonellia viridis
were obtained by the methods of scanning and transmission electron microscopy. Unusual concentric inclusions similar in the ultrastructure to those described in other animals, e.g., in the gut of many nematode species and in the tegument of some cestodes, were first found in the cells of the midgut. It is known that, in these animals, the concentric inclusions play an important role in the binding of chemical agents inherent in redox environments. Interestingly, the individuals of
B. viridis
studied were found on the surface of a substrate devoid of redox environment signs. New results indicate the presence in
B. viridis
and, possibly, in all spoon worms, of preadaptations to life in redox environments. New data on the structure and composition of concentric inclusions will shed light on their origin and function.
We developed a new test system to detect the omicron variant of SARS-CoV-2 using allele-specific reverse transcription PCR and estimated the frequency of its detection in patients living in the ...Novosibirsk Region. Clinical samples were divided into 3 groups: samples collected from December 1 to December 30, 2021 (group 1;
n
=66), from December 30, 2021 to January 10, 2022 (group 2;
n
=20), and from January 11 to January 22, 2022 (group 3;
n
=101). Based on the identification of 5 mutations specific to SARS-CoV-2 (B.1.1.529), two systems of oligonucleotide primers and probes were developed for detecting this coronavirus genotype in clinical samples. Limit of detection (LOD
95
) was 4×10
3
genome equivalents per 1 ml of clinical sample for the first test system and 2×10
3
for the for the second test system. The omicron variant of SARS-CoV-2 was absent in group 1 of studied samples, but was detected in 20% (4/20) of group 2 samples and 88% of group 2 samples collected within less than 2 weeks of January 2022. Using developed test system, we showed that in less than 2 weeks the omicron variant has become dominant in patients, which confirms previously published data on its exceptional contagiousness.
The authors have presented results of experimental investigations into the process of collisions of water droplets in a gas medium with variation of the basic parameters in wide ranges corresponding ...to advanced gas-vapor-droplet technologies: sizes (radii) 0.1–1 mm, velocities of travel 0–10 m/s, angles of interaction (attack) 0–90
o
, relative volume concentration 0.1–10
–3
–8.5·10
–3
m
3
of water/m
3
of the gas, velocity of motion of the flow 0–10 m/s, and temperature 20–1000
o
C; directions of flows: opposing, codirectional, and lateral. In processing the experimental results, the emphasis was on the influence of the relative volume concentrations of the droplets on the characteristics of their interaction. The relative probabilities of four typical regimes of interaction of the droplets have been calculated: recoil, coagulation, spread, and breakup (reduction in size). Parametric ranges have been shown for droplets for which the concentration growth of the latter in an aerosol leads to an increase in the probability of coagulation, recoil, and size reduction. Also, the authors have presented ranges of variation of the concentration of droplets in a gas medium, in which the probabilities of all the investigated interaction schemes are high. The experimental results have been processed with the existing approaches to generalization by calculating the angular factor of interaction and the Weber number.
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