335 research outputs found
Long-term impact of fecal transplantation in healthy volunteers
Fecal microbiota transplantation (FMT) has been recently approved by FDA for the treatment of refractory recurrent clostridial colitis (rCDI). Success of FTM in treatment of rCDI led to a number of studies investigating the effectiveness of its application in the other gastrointestinal diseases. However, in the majority of studies the effects of FMT were evaluated on the patients with initially altered microbiota. The aim of our study was to estimate effects of FMT on the gut microbiota composition in healthy volunteers and to monitor its long-term outcomes.Peer ReviewedPostprint (published version
Probiotic Wheat Drinks: Study of Secondary Metabolites and Bioactive Compounds
Abstract
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Background and Objective: Nowadays, there are a wide variety of probiotic beverages made from animal-derived ingredients that contain beneficial microorganisms for human health. In contrast, probiotic beverages made from plant-based sources are much less common, despite their organic acids, which are biologically active substances. The aim of the study was to quantitatively assess the concentration of secondary metabolites of yeasts and lactic acid bacteria in a fermented grain drinks, as well as sensory characteristics of the drinks.
Material and Methods: Probiotic beverage samples were produced wheat as their primary grain ingredient. Fermentation process involved use of various lactic acid bacteria strains, including Lactobacillus delbrueckii, Lactobacillus brevis, Lactobacillus buchneri, Lactobacillus plantarum and Lactobacillus fermentum as well as various strains of Saccharomyces cerevisiae yeasts. Additionally, commercially manufactured soft drinks made from grain-based ingredients were used as the basis for the comparison. Contents and concentrations of organic acids were analyzed using high-performance liquid chromatography, following the guidelines by the government standard. This technique involved separation of specific organic acids on a solid support using reversed-phase mechanism.
Results and Conclusion: The probiotic wheat drink contained 1300 mg.dm-3 lactic acid, suggesting the presence of lactic acid fermentation. Detection of citric and succinic acids of respectively 80 and 152 mg.dm-3 indicated heteroenzymatic nature of lactic acid fermentation. Therefore, development of aromas described as clove, fruity and banana-like was expected, generally considered favorable in the context of probiotic wheat drinks. Data make it possible to predict creation of the flavor profiles of fermented drinks from vegetable raw materials using complex combinations of lactic acid bacteria and yeasts.
Conflict of interest: The authors declare no conflict of interest
Influence of the bentonite-containing acrylic humectant composite on the soil microflora
ArticleAcrylic derivative-based superabsorbents are widely used currently in agriculture as
the soil conditioners, plant growth regulators, etc. Their usage has a positive effect on the growth
and survival of the plants cultivated in the arid regions. However, the effects of hydrophilic
acrylic polymers on the soil microbiocenosis still remain unknown. The influence of the moistureabsorbing acrylic acid-based hydrogels with different proportions of bentonite filler was studied
on the soil microbiota. N,N-methylenebisacrylamide was used as a crosslinking agent. Acrylic
hydrogels were synthesized by radical polymerization in an aqueous medium at a synthesis
temperature of 45 °C during 4 hours. The application of hydrogel of the certain concentrations
(1.0, 1.5, and 2.5% wt) into the soil did not cause significant changes in the total abundance of
heterotrophic bacteria and the length of the fungal mycelium. The CO2 emission rates did not
change after and during the application of the hydrogel), which indicated the same level of carbon
mineralization in the soil with presence of acrylic bentonite-containing hydrogels. The nitrogen
fixation rate decreased on the first day after hydrogel application; after 14 days, it was close to
the control values. We assume the activity of nitrogen-fixing bacteria has though turned to the
normal level
Polymer acrylic hydrogels with protein filler: Synthesis and characterization
ArticleThe water-retention hydrogel composites were synthesized by the free-radical
polymerization depending on the order of addition filler of the protein hydrolysate. As the filler
was used protein hydrolysate, ‘Biostim’, obtained by processing cattle hides. The influence of
gelation time on the synthesis parameters of hydrogel compositions was investigated. It is found
that the gelation time of the sample without filler is 2–2.5 times longer than filled of hydrogel
compositions. The structural characteristics of polymer composition by TGA, DSC and atomic
force microscopy were determined. FTIR spectra found decrease in the intensity of vibrations of
(-COO-) groups, indicating about additional ionic interactions. Decrease the beginning
evaporation temperature of polymer composites with increase concentration of protein filler,
indicating the destruction of the ordered structure of the polymer material revealed by
thermogravimetric analysis (TGA). The influence of various media, such as distilled water, saline
solution, and buffer solutions at differents pH on the swelling behavior of hydrogels was also
assessed. Maximum swelling capacity showed sample prepared with order of addition filler at the
end of synthesis (Scheme I). The kinetics of the release protein hydrolysate from the polymer
matrix was measurement by spectrophotometric method. The synthesized hydrogel composites
with protein hydrolysate and improved physicochemical properties are of practical interest as
water-retaining materials for increasing of crop the yield in agricultural
Assessment of essential oil yield in three mint species in the climatic conditions of Central Russia
Received: March 23rd, 2021 ; Accepted: June 9th, 2021 ; Published: June 30th, 2021 ; Correspondence: [email protected], [email protected] aim of the study was to study the harvest time for the essential oil yield and its
qualitative composition in three species of mint Mentha piperita L. (Peppermint), M. spicata L.
(Spearmint) and M. arvensis var. piperascens Malinv. ex. Holmes (Sakhalinmint). In 2018, the
research was performed with plants of second year of vegetation in the Laboratory of Plant
Physiology and Immunity of the NV Tsitsin Main Botanical Garden of the RAS. As a result, it
was found that the optimal harvest period for Sakhalinmint and Peppermint should be
recommended in a phase of mass flowering: the yield of fresh raw materials was 509–479 g m-2
,
air-dry raw materials - 110–107 g m-2
; the content of essential oil in the aboveground part
(a mixture of leaves and inflorescences) of plants - 3.24–4.01%; the proportion of the main
component of essential oil (menthol) - 57.3–50.2%. In Spearmint, the optimum time for
harvesting is the phase of budding. The content of the main component of essential oil (carvon)
was maximum - 67.9%, and the yield of essential oil was 2.6%, while the yield was 381 g m-2 of
fresh raw materials (81.9 g m-2 of air-dry raw materials) at harvesting in this ontogenesis stage.
Analysis of the secretory apparatus parameters on a surface of some green tissues in three mint
species showed that the maximum density of secretory glands on both sides of the leaf is
characteristic of peppermint, which provides a higher yield of essential oil in this type of mint.
The study allowed determining the optimal harvesting time for highly productive mint species
when they are grown in the conditions of Central Russia. The raw materials of these mint species
can be used for the production of essential oils and are of interest for pharmacology and the
perfume and cosmetics industry
Cluster superconductivity in the magnetoelectric Pb(Fe1/2Sb1/2)O3 ceramics
We report the observation of cluster (local) superconductivity in the
magnetoelectric Pb(Fe1/2Sb1/2)O3 ceramics prepared at a hydrostatic pressure of
6 GPa and temperatures 1200-1800 K to stabilize the perovskite phase. The
superconductivity is manifested by an abrupt drop of the magnetic
susceptibility at the critical temperature TC 7 K. Both the magnitude of this
drop and TC decrease with magnetic field increase. Similarly, the low-field
paramagnetic absorption measured by EPR spectrometer drops significantly below
TC as well. The observed effects and their critical magnetic field dependence
are interpreted as manifestation of the superconductivity and Meissner effect
in metallic Pb nanoclusters existing in the ceramics. Their volume fraction and
average size were estimated as 0.1-0.2% and 140-150 nm, respectively. The
superconductivity related effects disappear after oxidizing annealing of the
ceramics.Comment: 9 pages, 5 figure
Sorption Properties of Clay and Pectin-Containing Hydrogels
As is known, polymeric polyelectrolyte hydrogels are superabsorbents that are capable of absorbing moisture in amounts many times greater than their own mass. Numerous studies have shown that besides water absorption and retention, they can also be effectively used as sorbents to purify water from heavy metals. In many works, attempts are made to improve the sorption properties of polyelectrolyte hydrogels by creating polymer composites based on them. Organic/inorganic composite materials frequently exhibited desired hybrid performance superior to their individual components and cost-efficient characteristics. The composites derived from natural polysaccharides and inorganic clay minerals are of special interest by virtue of their unique commercial and environmental advantages, which means that the design and development of environmentally friendly superabsorbents, introducing natural ingredients, have long been necessary. In this paper, we consider polymer hydrogels based on a copolymer of acrylic acid and acrylamide filled with pectin and bentonite. The aim of this study is to investigate the influence of chemical conditions on hydrogels and their composites, kinetic, and absorption behavior toward metal ions in the presence of the chelating agent. In this chapter, an investigation of the kinetic patterns of swelling, deswelling, and sorption of the hydrogels and their composites will be presented
Dielectric characterization of the BiFe0.5Cr0.5O3 ceramics
Dielectric properties of the BiFe0.5Cr0.5O3 ceramics synthesized under high pressure were investigated in
a broad frequency range (20 Hz – 1 GHz) between 200 and 500 K. It was revealed that the ceramics exhibit
electrical conductivity above 300 K. Below 300 K, a dielectric dispersion caused by ferroelectric domains
was observed. It was found that the conductivity follows the Almond–West law, which allowed us to determine a DC contribution (σDC). From the σDC values obtained at different temperatures, the activation energy
(EA = 0.302 ± 0.006 eV) was calculated using the Arrhenius law.publishe
Spontaneous and induced ferroelectricity in the BiFe1−xScxO3 perovskite ceramics
High-pressure synthesis method allows obtaining single-phase perovskite
BiFe1-xScxO3 ceramics in the entire concentration range. As-prepared compositions with x from 0.30 to 0.55 have the antipolar orthorhombic Pnma structure
but can be irreversible converted into the polar rhombohedral R3c or the polar
orthorhombic Ima2 phase via annealing at ambient pressure. Microstructure
defects and large conductivity of the high-pressure-synthesized ceramics make it
difficult to study and even verify their ferroelectric properties. These obstacles can
be overcome using piezoresponse force microscopy (PFM) addressing ferroelectric behavior inside single grains. Herein, the PFM study of the BiFe1-xScxO3
ceramics (0.30 ≤ x ≤ 0.50) is reported. The annealed samples show a strong PFM
contrast. Switching of domain polarity by an electric field confirms the ferroelectric nature of these samples. The as-prepared BiFe0.5Sc0.5O3 ceramics
demonstrate no piezoresponse in accordance with the antipolar character of the
Pnma phase. However, application of a strong enough electric field induces
irreversible transition to the ferroelectric state. The as-prepared BiFe0.7Sc0.3O3
ceramics show coexistence of ferroelectric and antiferroelectric grains without
poling. It is assumed that mechanical stress caused by the sample polishing can
be also a driving force of phase transformation in these materials alongside
temperature and external electric field.publishe
Advancements in geodesy techniques for Arctic region monitoring
The Arctic region is undergoing unprecedented environmental changes due to global climate change, necessitating robust monitoring and research efforts. Geodesy, the science of accurately measuring Earth's shape, orientation, and gravitational field, plays a critical role in understanding these changes. This article explores the applications, challenges, and future directions of geodesy in the Arctic. Satellite-based techniques such as GNSS, SAR, and satellite altimetry are utilized to monitor ice mass loss, sea level rise, and land deformation with high precision. Challenges in Arctic geodesy include harsh environmental conditions, data accuracy, and the integration of multi-source data. Despite these challenges, ongoing advancements in satellite technology, data processing algorithms, and collaboration initiatives hold promise for addressing these issues and improving our understanding of Arctic environmental dynamics. By leveraging geodesy techniques and emerging technologies, researchers can contribute to the sustainable management of the Arctic environment and its broader implications for global climate change mitigation and adaptation
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