Binding Component Research Articles

Multi-organ phenotypes in mice lacking latent TGFβ binding protein 2 (LTBP2).

Latent TGFβ binding protein-2 (LTBP2) is a fibrillin 1 binding component of the microfibril. LTBP2 is the only LTBP protein that does not bind any isoforms of TGFβ, although it may interfere with the function of other LTBPs or interact with other signaling pathways. Here, we investigate mice lacking Ltbp2 (Ltbp2-/- ) and identify multiple phenotypes that impact bodyweight and fat mass, and affect bone and skin development. The alterations in skin and bone development are particularly noteworthy since the strength of these tissues is differentially affected by loss of Ltbp2. Interestingly, some tissues that express high levels of Ltbp2, such as the aorta and lung, do not have a developmental or homeostatic phenotype. Analysis of these mice show that LTBP2 has complex effects on development through direct effects on the extracellular matrix (ECM) or on signaling pathways that are known to regulate the ECM.

So sánh tính chất lớp phủ điện hóa PANI và Cu với vai trò bảo vệ thép kết cấu AH36 khỏi ăn mòn trong nước biển nhân tạo

Fabrication of PANI coating and Cu coating on the surface of AH36 shipbuilding structural steel was carried out by electrochemical method. PANI was electropolymerized onto AH36 surface in an aqueous solution of 0.5 M oxalic acid containing 0.1 M anilines. The process was conducted by cyclic voltammetry (CV) under a potential window of -0.5÷1.6 V at a scan rate of 10 mV/s with scans of 3, 5 and 8, respectively. The electrochemical deposition of Cu particles onto the AH36 surface was performed using chronoamperometry (CA) in a solution containing 0.3 M NaOH, 0.15 M EDTA, and 0.02 M CuSO4 at pH 8 and a constant applied potential of -1.1 V for 180s, 360s and 720s, respectively. SEM, FT-IR showed that the PANI coating with complex binding components characterizes the structure with diverse redox states while creating an amorphous, porous structure on the surface. Meanwhile, SEM, XRD, EDS spectra showed that the Cu plating has a particle structure, densely layered and pure on the steel substrate. The OCP trend and the polarization curve showed that both coatings protect the steel from corrosion by shift the potential of the coated material to a value where the kinetics of corrosion of the underlying metal are lowerred. Under the survey conditions, the PANI coating has a corrosion protection efficiency of up to about 31.9% while the Cu coating -66.9%.

C-reactive protein binds to short phosphoglycan repeats of Leishmania secreted proteophosphoglycans and activates complement.

Human C-reactive protein (CRP) binds to lipophosphoglycan (LPG), a virulence factor of Leishmania spp., through the repeating phosphodisaccharide region. We report here that both major components of promastigote secretory gel (PSG), the filamentous proteophosphoglycan (fPPG) and the secreted acid phosphatase (ScAP), are also ligands. CRP binding was mainly associated with the flagellar pocket when LPG deficient Leishmania mexicana parasites were examined by fluorescent microscopy, consistent with binding to secreted material. ScAP is a major ligand in purified fPPG from parasite culture as demonstrated by much reduced binding to a ScAP deficient mutant fPPG in plate binding assays and ligand blotting. Nevertheless, in sandfly derived PSG fPPG is a major component and the major CRP binding component. Previously we showed high avidity of CRP for LPG ligand required multiple disaccharide repeats. ScAP and fPPG only have short repeats but they retain high avidity for CRP revealed by surface plasmon resonance because they are found in multiple copies on the phosphoglycan. The fPPG from many species such as L. donovani and L. mexicana bound CRP strongly but L. tropica and L. amazonensis had low amounts of binding. The extent of side chain substitution of [-PO4-6Galβ1-4Manα1-] disaccharides correlates inversely with binding of CRP. The ligand for the CRP on different species all had similar binding avidity as the half maximal binding concentration was similar. Since the PSG is injected with the parasites into host blood pools and phosphoglycans (PG) are known to deplete complement, we showed that CRP makes a significant contribution to the activation of complement by PSG using serum from naive donors.

Effects of Jute Fiber on Fresh and Hardened Characteristics of Concrete with Environmental Assessment

Concrete is a widely utilized construction material globally; however, it is characterized by a fundamental deficiency in its tensile strength when it is not reinforced. The incorporation of diverse novel materials into concrete is being pursued with the aim of mitigating its limitations while concurrently enhancing its reliability and sustainability. Furthermore, it is noteworthy that concrete embodies a significant quantity of carbon. The primary cause of this phenomenon can be attributed to the utilization of cement as the principal binding component in concrete. Recent advancements in research have indicated that jute fiber, commonly referred to as JF, exhibits considerable potential as a novel material for enhancing the mechanical robustness of concrete. Although there is a significant body of literature on the application of jute fiber in concrete, there has been a dearth of research on the capacity of jute fiber (JF) to improve the mechanical strength of concrete and mitigate its carbon emissions. This study aims to cover a gap in the existing literature by analyzing and enhancing the application of JF in relation to its mechanical properties and environmental impact. The study involved conducting experiments wherein JF was added at varying weight percentages, specifically at 0%, 0.10%, 0.25%, 0.50%, and 0.75%. The investigation encompassed a number of examinations of both the fresh and hardened states of concrete, in addition to assessments of its durability. The fresh concrete tests included the slump test, while the hardened concrete tests involved measuring compressive strength (CS), split tensile strength (STS), and flexural strength (FS). Additionally, the durability tests focused on water absorption (WA). The study involved the computation of embodied carbon (EC) ratios for various mix combinations. The findings suggest that incorporating JF into concrete results in a decrease in environmental impact relative to alternative fiber types, as demonstrated by a rise in eco-strength efficiency (ESE). Based on the findings of the conducted tests, an optimal proportion of 0.10% JF has been determined to be conducive to enhancing the CS, STS, and FS by 6.77%, 6.91%, and 9.63%, respectively. The aforementioned deduction can be inferred from the results of the examinations. Using data obtained from extensive experimentation, the RSM (Response Surface Methodology) was used to construct a model. The model was optimized, resulting in the establishment of definitive equations that can be used to evaluate the effects of incorporating JF into concrete. Potential benefits have been identified for the advancement of concrete in the future through the utilization of JF.

Bacillus Strains Isolated from Korean Fermented Food Products with Antimicrobial Activity Against Staphylococci, an Alternative for Control of Antibiotic-Resistant Pathogens.

Multidrug resistance in foodborne and clinical pathogens is a worldwide health problem. The urgent need for new alternatives to the existing antibiotics is emerging. Bacteriocin-like inhibitory substances can be considered part of the new generation of antimicrobials, which can be potentially applied in the food industry and health care practices. This study aimed to select Bacillus strains with antimicrobial activity against Staphylococcus spp. with future application in the formulation of pharmaceutical antimicrobial preparations. Putative antimicrobial agent-producing strains, previously isolated and preidentified as Bacillus spp. were profiled by repetitive element sequence-based polymerase chain reaction (rep-PCR) and 16s rRNA sequencing identified the strains as Bacillus tequilensis ST1962CD with 99.47% identity confidence and as Bacillus subtilis subsp. stercoris ST2056CD with 98.45% identity confidence. Both the selected Bacillus strains were evaluated via biomolecular and physiological approaches related to their safety and virulence, beneficial properties, enzyme production profile, and presence of corresponding genes for the production of antimicrobials and virulence. Both strains were confirmed to harbor srfa and sbo genes and be free of hemolysin binding component (B) and two lytic components (L1 and L2) [BL] and nonhemolytic enterotoxin-associated genes. Produced antimicrobial agents by strains ST1962CD and ST2056CD were partially purified through the combination of ammonium sulfate precipitation and hydrophobic-based chromatography on SepPakC18 and evaluated regarding their cytotoxicity. The dynamics of bacterial growth, pH change, accumulation of produced antimicrobials, and the mode of action were evaluated. Obtained results were pointing to the potential application of safe B. tequilensis ST1962CD and B. subtilis subsp. stercoris ST2056CD strains as functional beneficial microbial cultures that are putative producers of surfactin and/or subtilosin, as potent antimicrobials, for the treatment of some staphylococcal-associated infections. Expressed antimicrobials were shown to be not cytotoxic, and appropriate biotechnological approaches need to be developed for cost-effective production, isolation, and purification of expressed antimicrobials by studied strains.

Индустриальная технология запеченных рыборастительных изделий

The level of scientific and technical literature related to the research topic is analyzed. Unexplored areas in the technique and technology of baked fish and vegetable products have been identified. In the process of research, the issues of combining lean fish species with products of animal and vegetable origin, mutually complementing the amino acid composition of the finished product, were considered. The main raw material for the manufacture of cutlets, soufflé, scrambled eggs and casseroles was fresh-frozen pollock fish with the addition of vegetable powders: sublimated dill, parsley and paprika, and onion, orange and yellow carrots, milk, butter and chicken eggs were used as vegetable and animal raw materials. . For heat treatment, sparing methods and modes of heat treatment were chosen: baking in a combi oven in the “steam” and “heat” modes. Based on the modeling of the components of the recipe, taking into account their biological value, new taste qualities of soufflé, casserole and scrambled eggs stuffed with the addition of powdered additives and vegetables that perform an additional structuring role were obtained. Soufflé, scrambled eggs and casserole prepared according to the traditional recipe available in the regulatory documentation were used as control. The dependences of raw and heat-treated products and their influence on the structure of soufflé and scrambled eggs are revealed. The sensory characteristics of new dishes were obtained, taking into account the processing in a combi steamer. The parameters of technological processes during baking in the "steam" and "heat" modes at a temperature of 180-200 ° C were established. The dependences of milk, eggs and butter on the binding components of the recipe - rice flour and powdered vegetable additives - were revealed. The resulting model composition of the recipes meets the requirements, regulatory documentation and consumer preferences. Comparative analysis of the content of essential amino acids in the developed products "Fish soufflé", "Fish baked with egg and milk sauce", "Smile stuffed omelette" and "Baked pollock cutlets" showed that the content of such amino acids as leucine, lysine, threonine , their phenylalanine is slightly higher than the control sample. They are characterized by a high content of essential amino acids that limit the biological value, g / 100 g of the product: lysine - 0.213-1.708; methionine - 0.104-0.570; tryptophan - 0.057-0.202.

APOBEC3B coordinates R-loop to promote replication stress and sensitize cancer cells to ATR/Chk1 inhibitors

The cytidine deaminase, Apolipoprotein B mRNA editing enzyme catalytic subunit 3B (APOBEC3B, herein termed A3B), is a critical mutation driver that induces genomic instability in cancer by catalyzing cytosine-to-thymine (C-to-T) conversion and promoting replication stress (RS). However, the detailed function of A3B in RS is not fully determined and it is not known whether the mechanism of A3B action can be exploited for cancer therapy. Here, we conducted an immunoprecipitation-mass spectrometry (IP-MS) study and identified A3B to be a novel binding component of R-loops, which are RNA:DNA hybrid structures. Mechanistically, overexpression of A3B exacerbated RS by promoting R-loop formation and altering the distribution of R-loops in the genome. This was rescued by the R-loop gatekeeper, Ribonuclease H1 (RNASEH1, herein termed RNH1). In addition, a high level of A3B conferred sensitivity to ATR/Chk1 inhibitors (ATRi/Chk1i) in melanoma cells, which was dependent on R-loop status. Together, our results provide novel insights into the mechanistic link between A3B and R-loops in the promotion of RS in cancer. This will inform the development of markers to predict the response of patients to ATRi/Chk1i.

Chloroquine-analogues block anthrax protective antigen channels in steady-state and kinetic studies

The tripartite anthrax toxin from Bacillus anthracis represents the prototype of A-B type of toxins, where the effector A (an enzymatic subunit) is transported with the help of a binding component B into a target cell. Anthrax toxin consists of three different molecules, two effectors, lethal factor (LF) and edema factor (EF) and the binding component also known as protective antigen (PA). PA forms heptamers or octamers following binding to host cell’s receptors and mediates the translocation of the effectors into the cytosol via the endosomal pathway. The cation-selective PA63-channel is able to reconstitute in lipid membranes and can be blocked by chloroquine and other heterocyclic compounds. This suggests that the PA63-channel contains a binding site for quinolines. In this study, we investigated the structure-function relationship of different quinolines for the block of the PA63-channel. The affinity of the different chloroquine analogues to the PA63-channel as provided by the equilibrium dissociation constant was measured using titrations. Some quinolines had a much higher affinity to the PA63-channel than chloroquine itself. We also performed ligand-induced current noise measurements using fast Fourier transformation to get insight in the kinetics of the binding of some quinolines to the PA63-channel. The on-rate constants of ligand binding were around 108 M−1·s−1 at 150 mM KCl and were only little dependent on the individual quinoline. The off-rates varied between 4 s−1 and 160 s−1 and depended much more on the structure of the molecules than the on-rate constants. The possible use of the 4-aminoquinolines as a therapy is discussed.

Adrenomedullin 2/intermedin is a slow off-rate, long-acting endogenous agonist of the adrenomedullin2 G protein–coupled receptor

Adrenomedullin 2/intermedin (AM2/IMD), adrenomedullin (AM), and calcitonin gene-related peptide (CGRP) have functions in the cardiovascular, lymphatic, and nervous systems by activating three heterodimeric receptors comprising the class B GPCR CLR and a RAMP1, -2, or -3 modulatory subunit. CGRP and AM prefer the RAMP1 and RAMP2/3 complexes, respectively, whereas AM2/IMD is thought to be relatively nonselective. Accordingly, AM2/IMD exhibits overlapping actions with CGRP and AM, so the rationale for this third agonist for the CLR-RAMP complexes is unclear. Here, we report that AM2/IMD is kinetically selective for CLR-RAMP3, known as the AM2R, and we define the structural basis for its distinct kinetics. In live cell biosensor assays, AM2/IMD-AM2R elicited longer-duration cAMP signaling than the other peptide-receptor combinations. AM2/IMD and AM bound the AM2R with similar equilibrium affinities, but AM2/IMD had a slower off-rate and longer receptor residence time, thus explaining its prolonged signaling capacity. Peptide and receptor chimeras and mutagenesis were used to map the regions responsible for the distinct binding and signaling kinetics to the AM2/IMD mid-region and the RAMP3 extracellular domain (ECD). Molecular dynamics simulations revealed how the former forms stable interactions at the CLR ECD-transmembrane domain interface and how the latter augments the CLR ECD binding pocket to anchor the AM2/IMD C terminus. These strong binding components only combine in the AM2R. Our findings uncover AM2/IMD-AM2R as a cognate pair with unique temporal features, reveal how AM2/IMD and RAMP3 collaborate to shape CLR signaling, and have significant implications for AM2/IMD biology.

Sunlight-Mediated Reductive Transformation of Thallium(III) in Acidic Natural Organic Matter Solutions: Mechanisms and Kinetic Modeling.

Thallium (Tl) redox state determines its speciation and fate in aqueous environments. Despite the high potential of natural organic matter (NOM) providing the reactive groups to complex and reduce Tl(III), the kinetics and mechanisms by which NOM influences the Tl redox transformation have remained insufficiently understood. Here, we studied the reduction kinetics of Tl(III) in acidic Suwannee River fulvic acid (SRFA) solutions under dark and solar-irradiated conditions. Our results show that the thermal Tl(III) reduction occurs by the reactive organic moieties in SRFA, with the electron-donating capacities of SRFA increased with pH and decreased with [SRFA]/[Tl(III)] ratios. Solar irradiation promoted Tl(III) reduction in SRFA solutions as a result of ligand-to-metal charge transfer (LMCT) within the photoactive Tl(III) species as well as an additional reduction process mediated by a photogenerated superoxide. We demonstrated that the formation of Tl(III)-SRFA complexes decreased the reducibility of Tl(III), with the kinetics dependent on the nature of the binding component and SRFA concentrations. A "three ligand class" kinetics model has been developed and satisfactorily describes Tl(III) reduction kinetics over a range of experimental conditions. The insights presented here should assist in understanding and predicting the NOM-mediated speciation and redox cycle of Tl in a sunlit environment.

Сultivation experiment of Origanum vulgare L. in Northern Kazakhstan using nitrogen fertilizer

The purpose of the research is to determine the effect of ammonium nitrate fertilizer on the growth and yield of Origanum vulgare L. essential oil grown in Northern Kazakhstan. One-factor analysis proved that the introduction of ammonium nitrate positively affected the growth and yield of O. vulgare L., the yield of essential oil and the content of its individual components. Plant height increased by 19.3%, bush size – by 17.4%, yield – by 11.8%. Essential oil output of O. vulgare L. at the experimental site, compared to the control site, increased by 20% and the yield of extraction reached 0.60% and 0.48%, respectively. The largest number of components was related to monoterpenes (52.57% in the experimental section, -50.10% in the control section), the most common were γ-Terpinene, β-Sabinene, Carvacrol and trans-β-Ocimene. Sesquiterpene content in the experimental sample was 37.19%, compared to 38.5250% in the control sample, in which Germacrene D and Caryophyllene were the most common components. Cluster analysis showed that the essential oil composition of O. vulgare L. from Kazakhstan is similar to the composition of the essential oil of plants from Moldova, Poland, Turkey (Anatolia), Latvia and Russia. Germacrene D, Carvacrol and β-Sabinene were the binding components of plants from Kazakhstan and Moldova. The similarity between plants from Kazakhstan and other countries in the same cluster was due to the Germacrene D content (cluster’s average value was 10.1%) and the content of Spathulenol (4.9%).

Benefits of co-translational complex assembly for cellular fitness.

Complexes of two or more proteins form many, if not most, of the intracellular "machines" that execute physical and chemical work, and transmit information. Complexes can form from stochastic post-translational interactions of fully formed proteins, but recent attention has shifted to co-translational interactions in which the most common mechanism involves binding of a mature constituent to an incomplete polypeptide emerging from a translating ribosome. Studies in yeast have revealed co-translational interactions during formation of multiple major complexes, and together with recent mammalian cell studies, suggest widespread utilization of the mechanism. These translation-dependent interactions can involve a single or multiple mRNA templates, can be uni- or bi-directional, and can use multi-protein sub-complexes as a binding component. Here, we discuss benefits of co-translational complex assembly including accuracy and efficiency, overcoming hidden interfaces, localized and hierarchical assembly, and reduction of orphan protein degradation, toxicity, and dominant-negative pathogenesis, all serving to improve cell fitness.

Construction of a Competitive Endogenous RNA Network Related to Exosomes in Diabetic Retinopathy.

The competing endogenous RNA (ceRNA) network plays an important role in the occurrence and development of a variety of diseases. This study aimed to construct a ceRNA network related to exosomes in diabetic retinopathy (DR). We explored the Gene Expression Omnibus (GEO) database and then analyzed the RNAs of samples to obtain differentially expressed lncRNAs (DELs), miRNAs (DEMs) and mRNAs (DEGs) alongside the progress of DR. Next, Gene Set Enrichment Analysis (GSEA) analysis of DEGs, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of up-DEGs were performed. In addition, a ceRNA network related to exosomes in DR was constructed on the base of DELs, DEMs and DEGs. Finally, the function of the ceRNA network was explored by GO and KEGG enrichment analysis. Through our analysis, 267 DELs (93 up and 174 down), 114 DEMs (64 up and 50 down) and 2368 DEGs (1252 up and 1116 down) were screened. The GSEA analysis results show that these genes were mainly related to cytokine-cytokine receptor interaction, hippo signaling pathway and JAK-STAT signaling pathway. The GO and KEGG results show that these up-DEGs were mainly enriched in viral gene expression, components of ribosomes, mineral absorption, Wntprotein binding, and TGF-β signaling pathway. Besides, a ceRNA network, including 15 lncRNAs (e.g., C1orf145, FGF14-IT1, and PRNT), 3 miRNAs (miR-10a-5p, miR-1297 and miR-507) and 11 mRNAs (NCOR2, CHAC1 and LIX1L, etc.) was constructed. Those 5 lncRNAs were up-regulated, 1 miRNA was down-regulated and 5 mRNAs were up-regulated in DR, while 10 lncRNAs were downregulated, 2 miRNAs were up-regulated and 6 mRNAs were down-regulated in DR. The novel ceRNA network that we constructed will provide new insights into the underlying molecular mechanisms of exosomes in DR.

Clostridioides difficile Binary Toxin Binding Component Increases Virulence in a Hamster Model.

Clostridioides difficile is the leading cause of hospital-acquired gastrointestinal infection, in part due to the existence of binary toxin (CDT)-expressing hypervirulent strains. Although the effects of the CDT holotoxin on disease pathogenesis have been previously studied, we sought to investigate the role of the individual components of CDT during in vivo infection. To determine the contribution of the separate components of CDT during infection, we developed strains of C difficile expressing either CDTa or CDTb individually. We then infected both mice and hamsters with these novel mutant strains and monitored them for development of severe illness. Although expression of CDTb without CDTa did not induce significant disease in a mouse model of C difficile infection, we found that complementation of a CDT-deficient C difficile strain with CDTb alone restored virulence in a hamster model of C difficile infection. Overall, this study demonstrates that the binding component of C difficile binary toxin, CDTb, contributes to virulence in a hamster model of infection.

Preparing high strength cementitious materials with high proportion of steel slag through reverse filling approach

Steel slag is an industrial solid waste with latent hydration nature, possessing a high potential use in cement and concrete but has not been fully utilized yet. This study reveals an implication approach based on dense packing to achieve high utilization efficiency of both steel slag and cement. Steel slag-based reverse filling approach utilizes higher volume of relatively coarser steel slag particles as micro fillers and a smaller quantity of fine cement grains as the major binding component. Thus, giving an initial compact packing structure and an enhanced strength of the resulting materials. Based on the packing density of various mixes, steel slag-based reverse filling cementitious materials are formulated. Early age hydration kinetics, fluidity of fresh pastes, and properties including mechanical strength and water absorption are further investigated on paste specimens. Results indicated that a maximum packing density of 0.6956 was attained for the blend containing 85 % steel slag with 15 % superfine Portland cement. The compressive strength of formulated mixes reached 96.4 MPa, 105.6 MPa and 123.8 MPa at 180 days for pastes containing 15 %, 25 % and 35 % of superfine Portland cement, respectively. The addition of appropriate amount of gypsum can enhance long-term strength by 8 ∼ 18 MPa through improving the early-age hydration kinetics of the steel slag based cementitious systems. The findings of this research help to valorize steel slag utilization in cement-based materials without sacrificing mechanical property and durability.

The CRL4DCAF6 E3 ligase ubiquitinates CtBP1/2 to induce apoptotic signalling and promote intervertebral disc degeneration.

Inflammation and apoptosis are two important pathological causes of intervertebral disc degeneration (IDD). The crosstalk between these two biological processes during IDD pathogenesis remains elusive. Herein, we discovered that chronic inflammation induced apoptosis through a cullin-RING E3 ligase (CRL)-dependent mechanism. Two cullin proteins, CUL4A and 4B, recruited DNA damage-binding protein 1 (DDB1), RING-box protein 1 (RBX1) and DDB1- and CUL4-associated factor 6 (DCAF6) to assemble a CRL4DCAF6 E3 ligase in intervertebral discs (IVDs) derived from IDD patients. The CRL4DCAF6 E3 ligase ubiquitinated and degraded C-terminal-binding protein 1 and 2 (CtBP1/2), two homologues of transcriptional corepressors. The degradation of CtBP1/2 disassociated from the p300-forkhead box O3a (FOXO3a) complex, inducing the expression of B-cell lymphoma 2 (Bcl2)-binding component 3 (BBC3) and causing BBC3-dependent apoptosis. TSC01131, a small molecule that specifically targets CUL4-DDB1 interaction, could inhibit the ubiquitination of CtBP1/2 in vitro and in vivo, thereby decreasing the BBC3 expression level and preventing apoptosis signalling. Using a mouse chronic inflammation model, we found that chronic inflammation could accelerate the IDD process through a conserved CRL4DCAF6-mediated mechanism. The administration of TSC01131 to mice could significantly improve the outcome of IDD. Collectively, our results revealed that inflammation-dependent CRL4DCAF6 E3 ligase triggered apoptosis through the removal of CtBP-mediated transrepression. The blockage of the CRL4DCAF6 E3 ligase by TSC01131 may represent a new therapeutic strategy for IDD treatment. KEY MESSAGES: CUL4A and CUL4B recruited DDB1, RBX1 and DCAF6 to assemble a CRL4DCAF6 E3 ligase in human IDD biopsies. The CRL4DCAF6 E3 ligase ubiquitinated and degraded CtBP1/2, causing BBC3-dependent apoptosis. A small molecule TSC01131 that specifically targets CUL4-DDB1 interaction could inhibit the ubiquitination of CtBP1/2, improving the outcome of IDD in a mouse model.

ПОВЫШЕНИЕ ЭКСПЛУАТАЦИОННЫХ ПОКАЗАТЕЛЕЙ ДОРОЖНЫХ ПОКРЫТИЙ С АСФАЛЬТОВЫМ ГРАНУЛЯТОМ

The condition of asphalt concrete and its standard service life on public roads are the main indicators of the road surface. The factors of violation of the top layer of asphalt concrete from increased dynamic effects of the wheel load of vehicles are considered. Performance indicators are characterized by strength and deformation characteristics. The factors providing the necessary deformation and strength parameters during the operation of the roadway are analyzed and justified. The indicators and conditions of contact of the surface of the crushed granulate in the zone of contact with the binding components are determined. A method of using asphalt granulate of three standard sizes in the formation of the top layer of pavement with a normative, operational service life and rational use of material and technical resources at all stages of the formation and laying of asphalt concrete is proposed. The strength of the dispersed system is achieved during the formation of an asphalt mixture by increasing the density, strength, adhesion of the binder, water resistance and preservation of the structure of the pavement. The experiment established the volumetric and fractional standard size of asphalt granulate in the total volume of the mixture. The volume composition of the granulate content in the total volume of the mixture is from 20% to 25%.

Association of personal and equipment-related factors on ACL injury risk in alpine skiers with cautious or risk-taking behaviour: A case-control study.

In recreational alpine skiing ACL injury risk depends on the interaction of individual characteristics and behaviours as well as on equipment-related factors. to evaluate if and to what extent personal characteristics and equipment-related parameters are associated with ACL injury risk in cautious and risk-taking recreational alpine skiers. A retrospective questionnaire-based, case-control study of ACL-injured and uninjured in a cohort of cautious as well as risk-taking recreational skiers was conducted. Participants self-reported their demographics, skiing skill level, and risk-taking behaviour. Ski length, side-cut radius, widths of the tip, waist, and tail were recorded from each participant's skis. Standing heights at the front and rear components of the ski binding were measured with a digital sliding caliper, and a standing height ratio between the front and rear components was calculated. Ski boot sole abrasion at the toe and heel pieces was also measured with the digital sliding caliper. In total, 1068 recreational skiers (50.8% females) with a mean age of 37.8 ± 12.3 years participated, of whom 193 (22.0%) sustained an ACL injury, and 330 (30.9%) participants reported a risk-taking behaviour. Results of the multiple logistic regression analyses revealed that a higher age, a lower skill level, a higher standing height ratio, and greater ski boot sole abrasion at the toe as well as heel pieces were independently associated with an increased ACL injury risk in both the cautious and the risk-taking group. Among cautious skiers, a longer ski length was an additional significant risk factor for sustaining an ACL injury. In conclusion, the same personal and equipment related characteristics contribute to an increase in the ACL injury risk regardless of risk-taking behaviour, with the only difference that longer skis represent an additional risk factor in cautious skiers.

Influence of heat treatment on the structure and properties of the tungsten-containing coating of the working part of oil and gas equipment

The influence of heat treatment modes on the structure and properties of the Ni – Cr – B – WC coating system applied by GDCS (cold flame spraying) on the working part of the Compressor Rod product of oil and gas equipment has been revealed. The optimal quenching mode for tungsten coating on AISI 4140 steel is recommended, including heating to temperatures of 1150 °C, exposure, followed by rapid cooling in a water-polymer medium. Using optical and scanning electron microscopy (SEM), the features of the formation of the structure and distribution of the carbide phase in the coating are determined. According to the structural analysis, after heat treatment, partial recrystallization of the binding components (Ni) occurs, redistribution of hardening particles (WC, Cr, B), which leads to a change in the structure and dispersion of the sprayed surface layer of the product. It is established that, depending on the parameters of heat treatment and further local remelting, an increase in interplate cohesion, a decrease in porosity, and a decrease in the microhardness of the coating base on average by 20 % of the initial value is observed, characteristic of this process. Recrystallization processes at the stage of heat treatment of the alloyed coating increase wear resistance despite a decrease in hardness. The achieved results make it possible to predict the possibility of using such products after heat treatment in a friction pair with increased requirements for wear resistance and adhesive strength.

Screening of the active Ingredients in Huanglian Jiedu decoction through amide bond-Immobilized magnetic nanoparticle-assisted cell membrane chromatography.

Introduction: The Huanglian Jiedu decoction (HLJDD) is a Chinese herbal formula that exerts neuroprotective effects by alleviating oxidative stress injuries and may potentially be prescribed for treating Alzheimer's disease; however, its active ingredients have not yet been identified. Cell membrane chromatography is a high-throughput method for screening active ingredients, but traditional cell membrane chromatography requires multiple centrifugation steps, which affects its separation efficiency. Magnetic nanoparticles are unparalleled in solid-liquid separation and can overcome the shortcomings of traditional cell membrane chromatography. Methods: In this study, the neuroprotective effects of the components of HLJDD were screened through a novel magnetic nanoparticle-assisted cell membrane chromatography method. Magnetic nanoparticles and cell membranes were stably immobilized by amide bonds. Magnetic bead (MB)-immobilized cell membranes of HT-22 cells were incubated with the HLJDD extract to isolate specific binding components. The specific binding components were then identified by ultraperformance liquid chromatography (UPLC)-Orbitrap Fusion Tribrid MS after solid-phase extraction. The bioactivity of these components was analyzed in an HT-22 cellular model of glutamate-induced injury. Results and Discussion: The preparation method of the composite of cell membrane and MBs has the advantages of simple preparation and no introduction of toxic organic reagents. MBs not only provide support for cell membranes, but also greatly improve the separation efficiency compared with traditional cell membrane chromatography. Fifteen of these components were found to specifically bind to the cell membranes, and seven of them were confirmed to reduce varying degrees of glutamate-induced toxicity in HT-22 cells. In conclusion, our findings suggest that the amide bond-based immobilization of magnetic nanoparticles on cell membranes, along with solid-phase extraction and UPLC, is an effective method for isolating and discovering the bioactive components of traditional Chinese medicines.