Defects induced by liquid-phase exfoliation of graphite using sonication were studied. It was shown that localized impact by cavitation shock waves can produce bulk ripplocations and various types of ...dislocations in graphite nanoplatelets. Formation of ripples is more pronounced in large aspect (length/width) ratio platelets or nanobelts. Quasi-periodical ripple systems were observed in many nanobelts after sonication. Mechanism of formation of ripples and dislocations during sonication was proposed. Surprisingly, fast high-temperature processing was found to anneal most of defects. This is consistent with our observations that defects associated with ripplocations are strongly localized and thus can be fast annealed.
A recombinant strain producing a complex of extracellular enzymes including chitinase from
Myceliophtora thermophila
was created based on the fungus
Penicillium verruculosum
. The activity of the ...enzyme preparations obtained from the cultural fluid of the producer strain was 0.55, 0.53, and 0.66 U/mg protein with chitin and chitosans with the molecular weight of 200 and 1000 kDa, respectively. The temperature optimum for the recombinant chitinase was 52-65°C; the pH optimum was 4.5-6.2, which corresponded to the published data for this class of the enzymes. The content of heterologous chitinase in the obtained enzyme preparations was 47% of total protein content in the cultural fluid. Enzyme preparations produced by the recombinant
P. verruculosum
XT403 strain and containing heterologous chitinase were able to degrade the mycelium of micromycetes, including phytopathogenic ones, and were very efficient in the bioconversion of microbiological industry waste.
The gene encoding Trichoderma harzianum fungus pustulanase (ThBGL1.6, GH5 family, endo-β-1,6-glucanase, EC 3.2.1.75) was cloned and heterologously expressed by the highly productive Penicillium ...verruculosum fungus. The recombinant ThBGL1.6 was purified and its properties were studied. The ThBGL1.6 had an observed molecular mass of 46 kDa (SDS-PAGE data) and displayed maximum of the enzyme activity at pH 5.0 and 50 °C. At 45 °C, the ThBGL1.6 was stable for at least 3 h. The Km was 1.0 g/L with pustulan as the substrate. Reaction product analysis by HPLC clearly indicated that ThBGL1.6 has an endo-hydrolytic mode of action against pustulan as specific substrate. It was also identified that gentiobiose is the main reaction product at studying of long-term pustulan hydrolysis.
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•ThBGL1.6 was successfully expressed into Penicillium verruculosum under the control of a strong cbh1 promoter.•The enzyme exhibited a high activity against pustulan by the endo-depolymerase type of action.•It was found that the main reaction product of pustulan hydrolysis by ThBGL1.6 was gentiobiose.
The
Penicillium verruculosum
filamentous fungus is a highly active producer of cellulolytic complex enzymes, cellobiohydrolases, endoglucanases and β-glucosidases. Using the CRISPR/Cas9 genome ...editing system, previously adapted to
P. verruculosum,
a strain with a knockout of the
xlnR
gene encoding XlnR, one of the main transcription factors of filamentous fungi, has been obtained. The transcription level of cellulolytic genes was determined by quantitative PCR for the
P. verruculosum
B1-221-151 strain and the new
P. verruculosum
ΔxlnR strain. The XlnR protein was shown to activate transcription of the
cbh1
,
egl2
, and
bgl1
genes encoding cellobiohydrolase 1, endoglucanase 2, and β-glucosidase, respectively, in the presence of xylose and xylooligosaccharides in the growth medium. It was found that other factors are also involved in the activation of transcription of these genes by cellobiose, cellotriose, sophorose, and gentiobiose, which has a complex effect on the biosynthesis of the cellulolytic complex of enzymes produced by the
P. verruculosum
fungus.
Objective.
The article addresses the process of heat and mass transfer in outer envelope structure with internal heat insulation. To prevent condensate formation, it is proposed to use a
ventilated ...air duct inside the wall structure.
Methods.
The study was carried out using numerical simulation methods. Air movement in the duct was described by solving the Navier-Stokes equation in k-ε approximation. Condensate formation was analysed via joint resolution of heat conduction and diffusion equations. The problem of heat and mass transfer was addressed for a structure with internal
heat insulation, behind the layer of which an air duct was located with air movement occurring due to
natural or forced convection.
Results.
As part of the work, it was shown that the use of an air duct
significantly reduces the thermal resistance of the structure, and an increase in the airflow rate leads
to a decrease in thermal resistance and the likelihood of condensate formation. A decrease in thermal
resistance with an increase in air flow rate into interlayers occurs faster than an increase in the
amount of air-entrained moisture.
Conclusion.
Results of the work have shown that the use of an air
duct throughout the entire period of operation of a building is not effective, but it is proposed to use
this duct periodically in winter to dry the condensate.
Assessment of peripheral visual acuity (VA) involves the need to split attention between the foveal fixation stimulus and the peripheral test stimulus. One approach to excluding the central fixation ...task consists of creating an artificial central scotoma using a contact lens with an implanted occluder (4–5 mm in diameter). Using this approach, we measured peripheral VA in three subjects over a range of eccentricities of up to 60° using a specially designed computerized perimetric apparatus using different optotypes – “tumbling E” letters and modified three-bar stimuli. In the conditions of our experiments, occlusion of the fixation stimulus did not itself lead to the expected increase in VA, probably because the effect of the instruction “look directly ahead” was analogous to the effect of the instruction “fix on the visible foveal stimulus.” Furthermore, it can be suggested that the contact lens with occluder had adverse effects because of veiling of the peripheral test stimulus in cases of uncontrollable involuntary decreases in pupil diameter, leading to significant increases in the blind zone. Peripheral VA in all subjects was somewhat higher for modified three-bar optotypes measuring “visual acuity” than for “tumbling E” letters measuring “recognition acuity.” Between-individual variability in the data was greater for smaller eccentricities.
The review presents data on the creation of highly active recombinant producer strains of a wide range of enzymes for various fields of industry and agriculture with the expression system of the ...filamentous fungus
Penicillium verruculosum
. These enzymes are endoglucanases, β-glucanases, xylanases, mannanases, phytases, α-galactosidases, pectin lyases, polygalacturonases, dextranases, exo-inulinases, and chitinases. The recipient strain
P. verruculosum
B1-537(Δ
niaD
) has a high secretory capacity (up to 60 g/L of extracellular protein in the culture liquid), and the recombinant producer strains are characterized by high productivity of the target enzymes: the obtained enzyme preparations contain, as a rule, 30–70% of the target recombinant enzymes (in some cases, up to 80%) of the total protein pool. The
P. verruculosum
expression system allows the easy transformation of expression constructs containing target heterologous or homologous genes that are functionally linked to the promoter and terminator of the strong inducible promoter of the cellobiohydrolase-1 gene (
cbh1
), and the recipient strain can be genetically transformed simultaneously with several vector constructs. The incorporation of target genes in the chromosome of the recipient strain is an integrative process, and the
foreign
recombinant proteins encoded by them are not subject to proteolysis. The technique for the primary selection of positive transformants on agar media, as well as secondary selection during their cultivation in shaking flasks and fermenters, is simple and reliable to use, in part due to standardized parameters, such as the nutrient composition of the fermentation medium and the culturing conditions for recombinant strains that produce various target enzymes. The time spent on the creation of a producer of the target enzyme, from the statement of the problem to the obtainment of a recombinant strain, is 3–6 months. It is important to emphasize that recombinant
P. verruculosum
strains are successfully used in industrial processes as producers of various target enzymes.
The acid-catalyzed reaction of substituted benzaldehydes with Girard’s reagent T leads to the formation of new water-soluble mixed ammonium-phosphonium salts. The obtained compounds exhibit high ...antimicrobial and moderate antitumor activities with low hemotoxicity.
As well as streamlining academic research activities, contemporary technologies provide opportunities to infringe on the intellectual property of others through plagiarism. However, plagiarism has ...yet to be adequately dealt with in national legislations, which either do not contain any provision in this connection or fail to adequately define the relevant terms. Moreover, there continues to be much discussion as to what plagiarism is, as well as how and in what cases it should be punishable. The situation is further complicated by the various approaches to plagiarism and the lack of consensus on whether so-called “self-plagiarism” should be treated separately from the intentional infringement of other people’s intellectual property or be deemed as a form of plagiarism. With the aim of clarifying these questions, the authors of the present paper compare different approaches taken to the problem of plagiarism and consider some contemporary approaches to plagiarism detection.
INTRODUCTION. Pharmacotherapy in elderly and senile patients is associated with multimorbidity and polypharmacy and can lead to adverse drug reactions (ADRs). The growth of the world’s population ...over 60 makes the practical application of the Beers Criteria for Potentially Inappropriate Medication Use in Older Adults, the key recommendations to optimise prescribing in the geriatric population, increasingly important. AIM. This study aimed to review the history of the Beers criteria, the main changes in the updated 2023 version, and national and international publications on the practical experience of using the criteria in healthcare settings. DISCUSSION. The criteria for assessing the rationality of pharmacotherapy in older patients were developed by Mark Beers in 1991. His recommendations have been regularly reviewed and updated by a panel of experts from the American Geriatrics Society (AGS); version 7 has been in effect since 2023. The criteria are designed to support pharmacotherapy decision making for adults 65 years old and older in all ambulatory, acute, and institutionalised settings of care, except hospice and end-of-life care settings. The criteria are organised into 5 categories: 1) medications that should be avoided in all older adults; 2) medications considered potentially inappropriate in patients with certain diseases or syndromes; 3) medications that should be used with caution; 4) medications that are potentially inappropriate due to the risk of clinically significant drug–drug interactions; 5) medications that should be avoided or require dosage reduction in patients with impaired renal function. Medicines with pronounced anticholinergic effects are categorised as a separate class. The criteria are based on expert grading of the quality of evidence and strength of recommendations. Compared with the previous version (2019), the updated AGS Beers Criteria® (2023) changed the most in terms of recommendations for anticoagulants and sulfonylureas. According to the results of this review, the AGS Beers Criteria® are actively used in healthcare practice in Russia and abroad to reduce the undesirable effects of potentially inappropriate medication use in elderly patients by optimising the selection of medicines and treatment regimens; to train healthcare providers and patients in the principles of rational pharmacotherapy; to reduce the cost of pharmacotherapy; and to assess the quality of medical care. CONCLUSIONS. The AGS Beers Criteria® are an effective tool for identifying potentially inappropriate medications in prescribed therapy and selecting appropriate alternatives. Their practical application in healthcare settings can reduce ADRs, hospital admissions, and mortality rates in elderly and senile patients.
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