N-hydroxyphthalimide (NHPI) is a promising catalyst in aerobic oxidation of hydrocarbons to corresponding hydroperoxides. We have found that a trace amount of Fe(benz)
3
or Fe(acac)
3
(in ...concentration of less than 10
−1
mmol/l and with the ratio of Fe(III): NHPI = 1:500) considerably accelerates the oxidation of cyclohexene and ethylbenzene, while retaining the selectivity to hydroperoxides at a level of 90%. As a consequence, the reaction temperature could be lowered down to 50–60 °C. The promoting effect of the additives was attributed to the ability of Fe(III) complexes to generate phthalimido-N-oxyl radicals (PINO) without participation in any transformations of hydrocarbon intermediates and hydroperoxides, thus ensuring selective formation and stability of the hydroperoxides.
Graphic Abstract
The biofilm formation by uropathogenic
E. coli
(UPEC) allows bacteria to avoid the influence of the host immune system that determines the pathogenesis of persistent urinary tract infections. The ...purpose of this work was to evaluate the mutual influence of neutrophils and biofilms formed by UPEC with different set of virulence-associated genes (VAGs).
E. coli
R11 and R32 strains with a wide range of virulence factors were characterized by low biofilm biomass that did not change after interaction with neutrophils. The biomass index decreased after interaction with neutrophils for strains with a limited set of pathogenicity factors (R33, R36, R45, and R44) and a “thick” biofilm. Bacterial cells and biofilm supernatants of all UPEC strains reduced viability (DiOC
6
(3)
+
/PI
—
) and stimulated early apoptosis (DiOC
6
(3)
—
/PI
—
) of neutrophils. The number of viable neutrophils was higher, while the number of apoptotic and necrotic (DiOC
6
(3)
—
/PI
+
) cells was lower under the action of supernatants of strains R44, R36, R45 in comparison with bacterial cells. Thus, modulation of the innate cell functions depends on the realization of the pathogenic potential of UPEC bacteria in urinary tract biofilms that determines the development of recurrent urinary tract infections.
The development of new biomarkers for prediction and early detection of human diseases, as well as for monitoring the response to therapy is one of the most relevant areas of modern human genetics ...and genomics. Until recently, it was believed that the function of human Y chromosome genes was limited to determining sex and controlling spermatogenesis. Thanks to occurance of large databases of the genome-wide association study (GWAS), there has been a transition to the use of large samples for analyzing genetic changes in both normal and pathological conditions. This has made it possible to assess the association of mosaic aneuploidy of the Y chromosome in somatic cells with a shorter lifespan in men compared to women. Based on data from the UK Biobank, an association was found between mosaic loss of the Y chromosome (mLOY) in peripheral blood leukocytes and the age of men over 70, as well as a number of oncological, cardiac, metabolic, neurodegenerative, and psychiatric diseases. As a result, mLOY in peripheral blood cells has been considered a potential marker of biological age in men and as a marker of certain age-related diseases. Currently, numerous associations have been identified between mLOY and genes based on GWAS and transcriptomes in affected tissues. However, the exact cause of mLOY and the impact and consequences of this phenomenon at the whole organism level have not been established. In particular, it is unclear whether aneuploidy of the Y chromosome in blood cells may affect the development of pathologies that manifest in other organs, such as the brain in Alzheimer’s disease, or whether it is a neutral biomarker of general genomic instability. This review examines the main pathologies and genetic factors associated with mLOY, as well as the hypotheses regarding their interplay. Special attention is given to recent studies on mLOY in brain cells in Alzheimer’s disease.
Approaches to increase the efficiency of Pt/C–heteropoly acid catalyst in a liquid-phase oxidation of cyclohexane using an O
2
–H
2
mixture were studied. It was shown that small additives of ionic ...liquid (BMImBr, Bu
4
NBr, or Bu
4
NHSO
4
) significantly improve the catalytic effect of the Pt/C–H
3
PMo
12
O
40
–CH
3
CN system at 35°C, by slowing the rate of side reactions resulting in water formation, increasing the rate of oxygenate formation, and inhibiting their secondary oxidation reactions. The efficiency of H
2
consumption increases from 2 to 18–25%, while the selectivity of cyclohexane conversion is 92–98%. The substitution of one or two Mo(VI) ions by V(V) in the structure of the heteropoly acid decreases these parameters. In the presence of Bu
4
NHSO
4
, a Pt/C catalyst can be used many times. During the reaction, the heteropoly acid present in the solution is in a reduced state under the action of the reaction medium and undergoes reversible redox transformations. The nature of the catalytic action of the studied system is explained from the viewpoint of the effect of ionic liquids on the properties of a Pt/C catalyst in activating O
2
, heteropoly molybdate chemistry, and the known mechanisms of the peroxide oxidation of hydrocarbons.
The Escherichia coli ZP strain (ZP) was constructed based on the known probiotic E. coli strain Nissle 1917. It was genetically modified to carry the colicin E7 synthesis gene encoding DNase on a ...conjugative plasmid and the colicin E7 immunity gene in the chromosome. The aim of this study was to evaluate the effects of the daily ZP per oral administration (5 x 10.sup.8 or 5 x 10.sup.10 CFU per bird) on the growth performance, hematological, biochemical, histological parameters, gut microbiota, and nonspecific immunity of the 4-24 days old broilers. The ZP administration increased the abundance of genera Bacillus, Butyrivibrio, and Clostridium and did not influence the weight gain of 4-16 days old broilers. The biochemical parameters were within normal ranges for poultry in experimental and control groups. The ZP administration had no effect on the erythrocyte numbers, hemoglobin and immunoglobulin Y concentrations, but significantly increased the serum lysozyme concentration, leukocyte numbers, and reactive oxygen species production by phagocytes compared with the control group. It did not cause inflammatory changes in intestinal mucosa, Peyer's patches, and spleen. Thus, the ZP had no detrimental effects on broiler health and could be an efficient probiotic for the broiler colibacillosis prophylaxis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Hydrogen peroxide and Pt activated mixture of gaseous O
2 and H
2 have been applied to oxidation of aromatic compounds in the presence of redox active heteropoly compounds in the form of acid H
4PMo
...11VO
40 and tetrabuthylammonium (TBA) salts TBA
4PMo
11VO
40 and TBA
4HPW
11Fe(OH)O
39. Benzene, toluene and phenol were subjected to hydroxylation of the ring, which was accompanied by secondary oxidation in the reaction with hydrogen peroxide. Oxygenation of toluene was equally directed to the ring and to methyl group. The total reactivity of substrates was increased in the order of benzene
<
toluene
<
phenol in oxidation by both O
2/H
2 and H
2O
2. Analysis of products yield and composition indicated the identical nature of active intermediates for both oxidants. It was suggested that HPC bonded radical species are responsible for the oxidation of hydrocarbons.
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•PdTe/C catalyst can participate competing radical chain and heterolytic route in liquid-phase oxidation of 1,3-butadiene.•Specific location of tellurium on the surface of palladium ...particles in the catalyst.•High selectivity to 1,4-butenediol derivatives in DMA (61%) and MeOH (84%).
A commercial Pd catalyst based on Sibunit carbon support was treated with H6TeO6 in a reducing media to obtain a Te coating on the surface of Pd particles. The PdTe/C catalyst prepared in this way showed the ability to control the radical chain oxidation of 1,3-butadiene by promoting the selective formation of 2-butene-1,4-diol, 4-hydroxybut-2-enal and furan in DMA (total selectivity of 61% and yield of 7%). At the same time, the catalyst induced oxidation of 1,3-butadiene by a non-radical heterolytic mechanism involving the formation of two groups of primary products: (1) сrotonaldehyde and methyl vinyl ketone and (2) the products of oxygenation at the 1,4-positions. The compounds of the second group including 1,4-dimethoxy-2-butene and maleic acid dimethyl ester were formed on PdTe centers in MeOH. Increasing the Te concentration in the PdTe/C catalyst forced the conversion of 1,3-butadiene toward 1,4-oxygenation and simultaneously decreased the intensity of secondary oxidation, resulting in the selective formation of derivatives of the 1,4-oxygenation—1,4-dimethoxy-2-butene and allenic alcohol methyl ether (total selectivity of 84% and yield of 48%).
Highly efficient oxidation of isopropylbenzene mediated by the system of NHPI/Fe(acac)3/Phen has been carried out at temperature as low as 60 °C. Significant improvement of catalysis by NHPI was ...associated with an enhanced oxidizing ability of Fe(III) tandem with Phen, which caused the intense generation of PINO. Furthermore, NMR observations revealed formation of a hydrogen-bonded NHPI-Phen adduct soluble in acetonitrile and isopropylbenzene. Based on this phenomenon, the system was applicable for the oxidation of solvent-free isopropylbenzene. The promise of the system of NHPI/Fe(acac)3/Phen for the selective synthesis of isopropylbenzene hydroperoxide was demonstrated by oxidation at a low content of Fe(acac)3.
Display omitted
•System of NHPI/Fe(acac)3/Phen mediates highly efficient oxidation of isopropylbenzene.•Phen promoted generation of PINO from NHPI and Fe(acac)3.•Phen causes NHPI solubility and oxidation of isopropylbenzene without solvent.
The article is devoted to the study of the microbiome of spontaneously fermented sourdoughs. The aim of the work was to study the influence of the technological parameters of sourdough propagations ...on the taxonomic structure of the microbiome of spontaneously fermented sourdoughs. Two spontaneously fermented sourdoughs were studied: dense rye sourdough and liquid rye sourdough, both prepared using the same batch of peeled rye flour. To study the taxonomic structure of the sourdough microbiome in dynamics, the method of high-throughput sequencing of 16S rRNA gene fragments of microorganisms was used. It was shown that the technological parameters of sourdough (humidity, temperature) do not affect the taxonomic composition of the microbiome of dense rye or liquid rye sourdough at the phylum/class/genus level. It was found that during the first three days of propagations, bacteria from the phyla Proteobacteria and Firmicutes dominated in the microbial community. In the phylum Proteobacteria, microorganisms from the order Enterobacterales took a large share, which persisted for three days of backslopping. The phylum Firmicutes was represented by lactic acid bacteria of the genera
Weissella
,
Lactobacillus
,
Leuconostoc
,
Pediococcus
,
Lactococcus
. It was established by classical microbiological methods that after a day of fermentation, the number of lactic acid bacteria cells was significantly higher in liquid rye sourdough compared to dense one. However, with further propagation of sourdoughs, the number of cells was comparable, while significant changes occurred at the level of genera and species. It was shown that as the relative number of lactic acid bacteria of the genus
Lactobacillus
increased, a gradual displacement of the coccal forms of
Lactococcus
,
Leuconostoc
,
Weissella
,
Pediococcus
happened. With further propagation of sourdough after 10 days, the position of the dominant groups of bacteria was occupied by representatives of the phylum Firmicutes, lactic acid bacteria of the genus
Lactobacillus
. The influence of the mode and parameters of the sourdough on the species composition of lactobacilli, which demonstrated a low bacterial diversity, is shown. In the first three days of propagations, lactobacilli
L. curvatus
,
L. brevis
, and
Lactiplantibacillus
sp. dominated in both sourdoughs. After a month of backslopping,
Fructilactobacillus sanfranciscensis
and
Companilactobacillus
sp. dominated in dense rye sourdough, and
L. pontis
dominated in liquid rye sourdough.
In this paper we investigate the relationship between the long-term variability of the Atlantic Meridional Overturning Circulation (AMOC) and the intensity of deep convection in the Greenland, ...Labrador, and Irminger seas, as well as with the intensity of wind induced upwelling in the Southern Ocean. This goal is achieved by extending the AMOC time series back to the 1950s using the AMOC ensemble index. The time variability of the intensity of deep convection over the 60-year study period is estimated using indices of deep convection, while upwelling in the Southern Ocean is estimated from the mean intensity of the divergence of Ekman transport. The contribution of each of the processes is assessed using cross-correlation and multiple regression analyses. The results suggest that during recent decades, the AMOC variations in the North Atlantic were mostly governed by the intensity of deep convection in the Irminger Sea and of upwelling in the Southern Ocean. Among these factors, the intensity of convection in the Irminger Sea has the largest impact on the observed variations in the AMOC.
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