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The common tendency of mine rail haulage improvement is to increase axial power of electrical equipment traction, wagon capacity, and enhancing the speed of movement. In this context, it is typical for mine machine-building design to equip only locomotives with brake facilities. Thus, specific value of braking force of a train cannot exceed basic specific resistance to its movement. Test results of carriage rolling stock as for its braking efficiency as well as for its structural and dynamic analysis of braking mechanism have shown that a shoe-wheel brake of mine locomotives is not efficient under operation brake conditions in terms of the parametric reliability indices; hence, it is not applicable as an analogue for a trailing train part. The objective of the research is to determine a type of structural uncertainty while identifying brake conditions for adaptive control of alternative-structure tribologic system. Practical implication of the results is to determine both type and parameters of empiric dependence of brake shoe friction on a wheel tread upon the speed and braking as well as upon determination of kinetic characteristic of carriage rolling stock brake to be used in the theory of a mine train haulage to provide its safety.

The roller vibratory classifier is equipped with an impact device for implementing vibro-shock mode, which improves the classification efficiency, especially of viscous and wet materials. The new device is a disk nozzle with blades, which are made like petals of wearresistant polymer. The immersion of a petal at a given depth in a crushed rock mass is investigated experimentally. Theoretical studies includes pair correlation and regression analysis methods. It is obtained that an increase in humidity promotes penetration and leads to a decrease in the energy necessary for impact, whereas an increase in particle size and layer thickness leads to its increase. Analysis of regression equations makes it possible to establish the percentage ratio of influencing factors. The article presents mathematical models of impact energy from variable factors for the initial moisture content of the material, including separately for small classes (-2.5 + 1) mm and further, with variation of all three parameters in the range: layer thickness – 20-40 mm, particle size 1-10 mm, humidity – up to 9 %. The obtained correlation dependencies and regression models are necessary for improving the existing and designing new blade-type roller vibratory classifiers.

When calculating the stress-strain state of a cylindrical drum of a mine hoisting machine loaded with a metal rope, the stiffness parameters of the elastic lining and frontal surface are taken into account. It is defined that, depending on the values of the radial and bending stiffness of the frontal surface, two zones can be distinguished. If the parameters of the frontal surface fall into the first of them, the stresses in the shell slightly differ from the stresses in the hinged supported shell. The second zone is characterized by a sharp (up to 70%) increase in stresses. An algorithm has been developed for selecting rational parameters of a lined drum, which allows to reduce the stresses in the metal shell by up to 20%.

The aim of the work is modelling of stressed condition of the loose mined rock thin layer between two parallel working plates of disintegrator, taking into consideration the dependences of the layer porosity and its side thrust coefficient on the main stress value with hereditary model of deformation accumulation. The equation of extreme balance of mined rock compactable thin layer is obtained for the case of its compression with partial sliding on working surfaces. It is shown, that there is no sliding in the central area of deformed zone, unlike the peripheral area. The iterative algorithm for parameters calculation of the layer stressed condition for the hypothesis of symmetric parabolic distribution of the axial normal stresses in the directions being perpendicular to the plates is developed. The distributions of the side thrust coefficient in the layer, the effective coefficient of external friction and the stresses of disintegrators working surfaces are grounded. The practical value of the research is the possibility to determine precisely the contact forces while crushing of fine-grained material taking into consideration its compactibility.

Background: Bile acids mediate gut-liver cross-talk through bile acid receptors. Serum, hepatic, and microbial bile acid metabolism was evaluated in HCV-compensated chronic liver disease., Methods: Patients underwent liver biopsy; portal and peripheral blood were obtained before (HCVi), and 6 months after sustained virologic response (SVR), splenic blood was obtained only after SVR. The fecal microbiome and liver transcriptome were evaluated using RNA-Seq. Twenty-four bile acids were measured in serum, summed as free, taurine-conjugated bile acids (Tau-BAs), and glycine-conjugated bile acids., Results: Compared to SVR, HCVi showed elevated conjugated bile acids, predominantly Tau-BA, compounded in HCVi cirrhosis. In the liver, transcription of bile acids uptake, synthesis, and conjugation was decreased with increased hepatic spillover into systemic circulation in HCVi. There was no difference in the transcription of microbial bile acid metabolizing genes in HCVi. Despite an overall decrease, Tau-BA remained elevated in SVR cirrhosis, mainly in splenic circulation. Only conjugated bile acids, predominantly Tau-BA, correlated with serum proinflammatory markers and hepatic proinflammatory pathways, including NLRP3 and NFKB. Among hepatic bile acid receptors, disease-associated conjugated bile acids showed the strongest association with hepatic spingosine-1-phosphate receptor 2 (S1PR2)., Conclusions: Enhanced expression of hepatic S1PR2 in HCVi and HCVi-cirrhosis and strong associations of S1PR2 with Tau-BAs suggest pathological relevance of Tau-BA-hepatic S1PR2 signaling in chronic liver disease. These findings have therapeutic implications in chronic liver diseases.

Ribosome heterogeneity has emerged as an important regulatory control feature for determining which proteins are synthesized, however, the influence of age on ribosome heterogeneity is not fully understood. Whether mRNA transcripts are selectively translated in young versus old cells and whether dysregulation of this process drives organismal aging is unknown. Here we examined the role of ribosomal RNA (rRNA) methylation in maintaining appropriate translation as organisms age. In a directed RNAi screen, we identified the 18S rRNA N6'-dimethyl adenosine (m 6,2 A) methyltransferase, dimt-1, as a regulator of C. elegans lifespan and stress resistance. Lifespan extension induced by dimt-1 deficiency required a functional germline and was dependent on the known regulator of protein translation, the Rag GTPase, raga-1, which links amino acid sensing to the mechanistic target of rapamycin complex (mTORC)1. Using an auxin-inducible degron tagged version of dimt-1, we demonstrate that DIMT-1 functions in the germline after mid-life to regulate lifespan. We further found that knock-down of dimt-1 leads to selective translation of transcripts important for stress resistance and lifespan regulation in the C. elegans germline in mid-life including the cytochrome P450 daf-9, which synthesizes a steroid that signals from the germline to the soma to regulate lifespan. We found that dimt-1 induced lifespan extension was dependent on the daf-9 signaling pathway. This finding reveals a new layer of proteome dysfunction, beyond protein synthesis and degradation, as an important regulator of aging. Our findings highlight a new role for ribosome heterogeneity, and specific rRNA modifications, in maintaining appropriate translation later in life to promote healthy aging., Competing Interests: Competing interests: Authors declare no competing interests.

Ribosome heterogeneity has emerged as an important regulatory control feature for determining which proteins are synthesized, however, the influence of age on ribosome heterogeneity is not fully understood. Whether mRNA transcripts are selectively translated in young versus old cells and whether dysregulation of this process drives organismal aging is unknown. Here we examined the role of ribosomal RNA (rRNA) methylation in maintaining appropriate translation as organisms age. In a directed RNAi screen, we identified the 18S rRNA N6'-dimethyl adenosine (m 6,2 A) methyltransferase, dimt-1, as a regulator of C. elegans lifespan and stress resistance. Lifespan extension induced by dimt-1 deficiency required a functional germline and was dependent on the known regulator of protein translation, the Rag GTPase, raga-1, which links amino acid sensing to the mechanistic target of rapamycin complex (mTORC)1. Using an auxin-inducible degron tagged version of dimt-1, we demonstrate that DIMT-1 functions in the germline after mid-life to regulate lifespan. We further found that knock-down of dimt-1 leads to selective translation of transcripts important for stress resistance and lifespan regulation in the C. elegans germline in mid-life including the cytochrome P450 daf-9, which synthesizes a steroid that signals from the germline to the soma to regulate lifespan. We found that dimt-1 induced lifespan extension was dependent on the daf-9 signaling pathway. This finding reveals a new layer of proteome dysfunction, beyond protein synthesis and degradation, as an important regulator of aging. Our findings highlight a new role for ribosome heterogeneity, and specific rRNA modifications, in maintaining appropriate translation later in life to promote healthy aging., Competing Interests: Competing interests: Authors declare no competing interests.

Introduction: Perturbations in aromatic (AAAs) and branched-chain amino acids (BCAAs) are seen in decompensated liver disease. The aim of this study was to evaluate the dynamic, postprandial relationship between hepatitis C virus-induced liver disease and amino acid concentrations in patients with compensated liver disease., Methods: Patients infected with hepatitis C virus underwent a baseline liver biopsy to determine Ishak Fibrosis Score and evaluate the liver transcriptome. Patients ate a standard meal and underwent peripheral vein sampling at defined intervals. Quantitative analysis of amino acids was performed using liquid chromatography-tandem mass spectrometry., Results: At baseline, there was no difference in AAA and BCAA concentrations between patients with cirrhosis and non-cirrhotic patients. After a standard meal, AAAs, but not BCAAs, were elevated in patients with cirrhosis compared with non-cirrhotic patients at every time point. The HepQuant SHUNT fraction was significantly higher in patients with cirrhosis and positively correlated with AAA concentration at all time points, but not BCAA. Analysis of the hepatic transcriptome demonstrated greater downregulation of the AAA degradation pathways than the BCAA degradation pathways., Discussion: At baseline, cirrhotic patients with compensated liver disease have adequate reserve liver function to metabolize AAAs and BCAAs. When faced with a metabolic stressor, such as a standard meal, patients with cirrhosis are less able to metabolize the increased load of AAAs. This impairment correlates with portosystemic shunting. Further evaluation of AAA levels in compensated liver disease might further the understanding of the liver-muscle axis and the role it may play in the development of sarcopenia in liver disease., (Copyright © 2024 Written work prepared by employees of the Federal Government as part of their official duties is, under the U.S. Copyright Act, a “work of the United States Government” for which copyright protection under Title 17 of the United States Code is not available. As such, copyright does not extend to the contributions of employees of the Federal Government.)

Cell-free RNAs (cfRNAs) are promising analytes as non-invasive biomarkers and have even greater potential if tied in with metabolomics. Plasma is an optimal source for cfRNAs but is often derived from a variety of anticoagulants. Plasma obtained in heparin is suitable for metabolomics but is difficult to utilize for qPCR-based downstream analysis. In the present study, we aimed to develop a simple, time-efficient, and cost-effective heparinase protocol, followed by library preparation and sequencing of human plasma cfRNAs drawn and stored in heparin at -80 °C for several years. Blood was collected in CPT™ sodium heparin tubes from patients with chronic HCV infection (NCT02400216) at the National Institutes of Health (NIH) Clinical Center. Plasma cfRNAs were treated with heparinase I and used for library preparation and next-generation sequencing (NGS). Heparinase treatment maintained RNA integrity and allowed for successful library preparation for all the study subjects even with 7 ng of cfRNAs as starting material. The classification report derived from Pavian R package v1.2.0 showed no artificial reads. The abundance of chordate over microbial reads suggests no addition of experimental error through heparinase I treatment. We report a novel and practical approach to heparinase treatment for human plasma collected and frozen in sodium heparin for several years. This is an effective demonstration of utilizing heparin plasma for NGS and downstream transcriptomic research, which could then be integrated with metabolomics from the same samples, maximizing efficiency and minimizing blood draws.

The gut and liver are connected via the portal vein, and this relationship, which includes the gut microbiome, is described as the gut-liver axis. Hepatitis C virus (HCV) can infect the liver and cause fibrosis with chronic infection. HCV has been associated with an altered gut microbiome; however, how these changes impact metabolism across the gut-liver axis and how this varies with disease severity and time is unclear. Here we used multi-omics analysis of portal and peripheral blood, faeces and liver tissue to characterize the gut-liver axis of patients with HCV across a fibrosis severity gradient before (n = 29) and 6 months after (n = 23) sustained virologic response, that is, no detection of the virus. Fatty acids were the major metabolites perturbed across the liver, portal vein and gut microbiome in HCV, especially in patients with cirrhosis. Decreased fatty acid degradation by hepatic peroxisomes and mitochondria was coupled with increased free fatty acid (FFA) influx to the liver via the portal vein. Metatranscriptomics indicated that Anaerostipes hadrus-mediated fatty acid synthesis influences portal FFAs. Both microbial fatty acid synthesis and portal FFAs were associated with enhanced hepatic fibrosis. Bacteroides vulgatus-mediated intestinal glycan breakdown was linked to portal glycan products, which in turn correlated with enhanced portal inflammation in HCV. Paired comparison of patient samples at both timepoints showed that hepatic metabolism, especially in peroxisomes, is persistently dysregulated in cirrhosis independently of the virus. Sustained virologic response was associated with a potential beneficial role for Methanobrevibacter smithii, which correlated with liver disease severity markers. These results develop our understanding of the gut-liver axis in HCV and non-HCV liver disease aetiologies and provide a foundation for future therapies., (© 2022. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Regulation of cell architecture is critical in the formation of tissues during animal development. The mechanisms that control cell shape must be both dynamic and stable in order to establish and maintain the correct cellular organization. Previous work has identified Shroom family proteins as essential regulators of cell morphology during vertebrate development. Shroom proteins regulate cell architecture by directing the subcellular distribution and activation of Rho-kinase, which results in the localized activation of non-muscle myosin II. Because the Shroom-Rock-myosin II module is conserved in most animal model systems, we have utilized Drosophila melanogaster to further investigate the pathways and components that are required for Shroom to define cell shape and tissue architecture. Using a phenotype-based heterozygous F1 genetic screen for modifiers of Shroom activity, we identified several cytoskeletal and signaling protein that may cooperate with Shroom. We show that two of these proteins, Enabled and Short stop, are required for ShroomA-induced changes in tissue morphology and are apically enriched in response to Shroom expression. While the recruitment of Ena is necessary, it is not sufficient to redefine cell morphology. Additionally, this requirement for Ena appears to be context dependent, as a variant of Shroom that is apically localized, binds to Rock, but lacks the Ena binding site, is still capable of inducing changes in tissue architecture. These data point to important cellular pathways that may regulate contractility or facilitate Shroom-mediated changes in cell and tissue morphology., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)

Background: Increased microbial translocation (MT) into the systemic circulation is associated with liver disease progression. Microbial translocation has yet to be completely defined in chronic hepatitis B virus (HBV) and chronic hepatitis delta virus (HDV)., Methods: Our aim was to characterize MT and associated immune response in chronic HBV and HDV at various stages of disease. Serum from 53 HBV, 43 HDV, and 36 healthy control (HC) subjects was obtained. Subjects were categorized by aspartate aminotransferase-to-platelet ratio index into mild (<0.5), moderate, and severe (>1.0) disease. Cytokines, microbial products, and microbial deoxyribonucleic acid (DNA) levels were assessed in a single treatment-naive time point for each patient. Next-generation sequencing identified bacterial species present within patient sera., Results: The HBV and HDV subjects display higher serum concentrations of Gram-negative (G - ) bacterial lipopolysaccharide and fungal beta-glucan compared with HC (all P < .01). Gram-positive (G + ) bacterial peptidoglycan is higher in HBV compared to HDV and HC (both P < .0001). Within both disease cohorts, peptidoglycan correlates with interleukin (IL)-1b, IL-8, IL-12p70, and IL-13 (all Spearman's rho >0.45; P < .05). Next-generation sequencing from 7 subjects with detectable serum bacterial DNA revealed changes in abundance of bacterial taxa and a higher proportion of Gram-positive genera in severe disease. Greater G + /G - taxa ratio is associated with higher cytokine levels and disease markers., Conclusions: The HBV and HDV patients display increased translocation of bacterial and fungal products into serum. An increased proportion of Gram-positive genera is associated with disease progression. Correlations of peptidoglycan with antimicrobial cytokines suggest that particular microbial classes may contribute to systemic inflammation and possibly disease progression., (Published by Oxford University Press on behalf of Infectious Diseases Society of America 2020.)

There is today an exponential increase in prevalence of type 2 diabetes mellitus (T2DM), especially in young people. This downward shift in age of onset of T2DM has been shown by abundant evidence to be due to an increase in obesity among the young, the latter mainly attributable to unhealthy dietary habits and a sedentary lifestyle. It is therefore obvious that the prevention of diabetes rather its treatment is of is paramount importance. In the past decade, because concerns about the safety of antidiabetic agents took precedence over the issue of efficacy, almost all studies have been diabetes CVOTs and not traditional CVOTs. Until 2015, the evidence showed that antidiabetic agents are effective in terms of reduction of microvascular, as opposed to macrovascular, complications. However, following publication of the results of some new studies, it became clear that the new class of antidiabetic drugs, e.g., SGLT 2 inhibitors and GLP-1 agonists, are also effective in reducing cardiovascular disease (CVD). In the coming decade, numerous health challenges are expected to arise, the most important being the greater expansion of the therapeutic armamentarium for T2DM and the adoption of strategies for prevention of CVDs. In parallel, the new generation of antidiabetic agents will target the recently investigated pathophysiologic disorders of diabetes, while, ideally, treatments should include smart drugs without side effects.

Objective: To test the hypothesis that routine preoperative mapping and transposed brachial-basilic vein fistula (TBBVF) increases arteriovenous fistulae (AVFs) construction rates, without altering maturation rate., Patients: Over a 4-year period, 709 vascular accesses were performed, including 467 AVFs (radial-cephalic fistula [RCF], n = 217, brachial-cephalic fistula [BCF], n = 139, TBBVF, n = 111) and 251 prosthetic grafts. During the last 2 years, preoperative mapping was performed routinely by means of ultrasound, and TBBVFs were preferentially used over arteriovenous grafts (AVGs)., Results: Over the study, construction rate of upper arm AVF increased significantly from 12% to 53% and use of prosthetic grafts decreased from 55% to 19% (P < .001). Maturation rate of RCFs, BCFs, and TBBVFs during the first part of the study was 75%, 50%, and 30% (P = .003), compared to 79%, 82%, and 86% (P = .43), respectively, during the second part., Conclusions: Routine preoperative upper extremity mapping with ultrasound increases not only AVF construction rate, but also their maturation likelihood.

Background: Previous studies have shown that stenosis of the arterial anastomosis of thrombosed hemodialysis (HD) grafts, unmasked after conventional thrombectomy, very often necessitate subsequent arterial angioplasty. The aim of this study was to describe a novel fluoroscopic-assisted balloon thrombectomy technique which permits simultaneous arterial angioplasty (should this is required) for thrombosed HD grafts., Methods: Thirty patients with 36 thrombotic episodes of their prosthetic HD grafts participated in this study. A balloon angioplasty catheter is placed beyond the arterial anastomosis, over a guidewire; the balloon is inflated with contrast solution under fluoroscopy and pulled back to remove the arterial thrombus from the anastomosis. Any coexisting stenosis revealed by balloon indentation is completely dilated at that time, rather than after the thrombectomy. Mechanical thrombolysis of the graft and venous outflow is then performed with the AngioJet catheter (Possis Medical, Inc)., Results: Technical and clinical success rates (the latter defined as one subsequent HD session) of the procedure were 100% and 94%, respectively. No complications, including arterial embolism, vessel rupture or pulmonary embolism, were encountered. Primary assisted patency at 3 and 6 months was 51% and 32%, respectively, while functional secondary patency at the same follow-up points was 78%., Conclusions: Our technique is safe and also effective in both short- and long-term follow-up. Because it offers convenience, since the treatment of arterial anastomotic stenoses is accomplished in one (rather than two) steps, this method deserves further investigation.

Background: To study the long-term patency of thrombosed prosthetic vascular access grafts treated with percutaneous mechanical thrombectomy (PMT) followed by aggressive surveillance and monitoring and repeated endovascular interventions., Study Design: Two hundred seven vascular access grafts presented with first-time thrombosis were treated with PMT using the AngioJet device (n=185) or the Arrow-Trerotola percutaneous thrombolytic device (n=22) followed by angioplasty (+/- stenting) of the anatomical lesion responsible for the thrombotic event. Clinical success was considered at least one successful subsequent hemodialysis session. Graft surveillance/monitoring included clinical and hemodialysis parameters to detect a failing or thrombosed graft., Results: PMT was technically successful in 202 cases (97.6%) and clinically successful in 193 cases (93.2%). During follow-up, 149 got thrombosed and either abandoned (n=33) or underwent at least once repeat thrombectomy (n=116); finally 100 grafts were abandoned (n=90), ligated (n=5) or removed (n=5). Endovascular management (0.54 procedures per 100 graft-days, thrombectomy, n=307 sessions and angioplasty, n=162 sessions) increased significantly functional assisted-primary patency rates from 29% and 14% at 1 and 2 years to a secondary patency of 62% and 47%, respectively. Secondary patency was worse in loop grafts (P=.02) and intermediate graft thrombosis (occurred between 31-182 days after graft placement, P<.001) and better when renal failure was due to hypertension or diabetes (compared to other or cryptogenic causes, P=.048) or isolated angioplasty for graft dysfunction during follow-up had been performed (P<.001). Multivariate analysis identified intermediate graft thrombosis and isolated angioplasty as independent predictors of secondary patency (P<.001, relative risk 2.77 and P<.001, relative risk 0.28, respectively)., Conclusions: PMT is a highly successful procedure with acceptable long-term secondary patency results, provided that aggressive endovascular management of subsequent thrombotic or dysfunction episode is performed. Further research to identify the causes of intermediate graft thrombosis is justified.

Objectives: The 2006 update of the DOQI guidelines has stated that in patients with end-stage renal disease, autogenous radial-cephalic, or brachial-cephalic fistulas are the preferred access modalities, followed by transposed brachial-basilic (TBB) fistulas and prosthetic arteriovenous (AV) grafts. AV grafts are in general least preferred; however, there is very limited data comparing directly the last two modalities. The aim of the present study is to compare outcomes of the TBB fistula and the Vectra Vascular Access Graft., Methods: Seventy-six patients had a prosthetic brachial-axillary Vectra graft placed, while in 41 patients brachial-basilic upper arm transposition was performed. Graft surveillance to detect a failing/failed access was followed by endovascular treatment, rheolytic thrombectomy (AngioJet, Possis Medical), and/or angioplasty +/- stenting of the responsible anatomical lesion(s)., Results: Use of Vectra grafts and TBB fistulas started after a median (interquartile range) of 14 (7-30) and 70 (52-102) days, respectively (P < .001), as early as the operative day in some patients with grafts. Postoperative complications were more frequent in TBB fistulas and late complications (mainly access thrombosis) in Vectra grafts. Total number of thrombectomy sessions performed for graft or fistula occlusion was 45 and 7, respectively (P = .032); total number of isolated angioplasty sessions, performed for failing graft or fistula was 31 and 45, respectively (P = .004). Although primary patency of the two access modalities was equivalent, primary assisted patency was significantly reduced in Vectra grafts (70% at 12 months and 58% at 18 months), compared with TBB fistulas (82% at 12 months and 78% at 18 months, P = .033); however, as a result of endovascular intervention, secondary patency rates at 12 months (87% vs 88%) and 18 months (87% vs 83%) were equivalent (P = .91). Presence of arterial anastomosis stenosis treated with angioplasty at any stage had a significant negative predictive value on secondary patency rates at 12 and 18 months which were 61%, compared with 96% for Vectra grafts that had any intra-graft, venous outflow, draining or central vein stenosis treated with angioplasty at any stage (P = .010)., Conclusions: Aggressive graft surveillance and endovascular treatment methods can yield equivalent long-term secondary patency rates between Vectra graft and TBB fistulas. The advantage of earlier use of Vectra graft must be balanced against the need for more frequent secondary interventions and the risk of graft infection.