Mechanism Of Destruction Research Articles

Language Game in Ergonymic Nominations: Provocativeness and Emotional and Communicative Reception

The problem field of this article lies in the examination of the mechanisms of modelling and reading the codes of language game in the aspect of their emotional and evaluative impact (including negative) on an individual’s consciousness. The author refers to game nominations of different objects in Yekaterinburg. She proceeds from the theoretical provisions on the complex polycode (multimodal) nature of human emotions, which determines the need for a comprehensive (linguistic, psychological, and psycholinguistic) approach to the analysis of discursive practices of speech activity. The author focuses on the phenomenon of language game understood as a form of lingua-creative thinking based on associative mechanisms of destruction and switching of perception stereotypes, modelling, and using verbal signs. The decoding of the linguistic game unit involves the identification of its prototype and the awareness of a special linguistic technique for its transformation. From this point of view, decoding game ergonyms appears as a reflexive act in which emotional and evaluative projections of their perception manifest themselves. In the light of linguistic technique, the author distinguishes ergonymic linguistic createmes emphasising the emotional and evaluative charge of the motivators used, and game ergonyms modelled using the principles of associative provocation, associative identification, associative derivability, and associative overlay. The article considers ergonymic game units and linguistic createmes, respectively, in the light of pragmatic attitudes and emotional-evaluative vectors of influence on the consciousness of various urban population groups. Additionally, the author pays special attention to emotional-evaluative negative attitudes as planned or unplanned reactions of the nominee to the game ergonym or ergonymic linguistic createmes. Examples of the first type are provocative ergonyms that intentionally cause emotional shock (at primary perception); the second type of game ergonyms and ergonymic linguistic createmes does not imply a negative reaction of the addressee, but their perception encounters communicative barriers – linguistic, social, role-playing, psychological, ideological, aesthetic, etc. To check the positive or negative assessment of the respective nominations, the analysis uses data from psycholinguistic experiments conducted by the author by interviewing random respondents of different gender and age and social and professional status among urban residents. Finally, the author makes a conclusion regarding the zones of negative emotions in the game ergonymic continuum and outlines the prospects of an in-depth experimental study of the psychological reality of the perception of such nominations by bearers of urban culture.

Photomagnetically Powered Spiky Nanomachines with Thermal Control of Viscosity for Enhanced Cancer Mechanotherapy.

Nanomachines with active propulsion have emerged as an intelligent platform for targeted cancer therapy. Achieving an efficient locomotion performance using an external energy conversion is a key requirement in the design of nanomachines. In this study, inspired by diverse spiky structures in nature, a photomagnetically powered nanomachine (PMN) with a spiky surface and thermally dependent viscosity tunability is proposed to facilitate mechanical motion in lysosomes for cancer mechanotherapy. The hybrid nanomachine is integrated with magnetic nanoparticles as the core and covered with gold nanotips. Physical simulations and experimental results prove that the spiky structure endows nanomachines with an obvious photomagnetic coupling effect in the NIR-II region through the alignment and orienting movement of plasmons on the gold tips. Using a coupling-enhanced magnetic field, PMNs are efficiently assembled into chain-like structures to further elevate energy conversion efficiency. Notably, PMNs with the thermal control of viscosity are efficiently propelled under simultaneously applied dual external energy sources in cell lysosomes. Enhanced mechanical destruction of cancer cells via PMNs is confirmed both in vitro and in vivo under photomagnetic treatment. This study provides a new direction for designing integrated nanomachines with active adaptability to physiological environments for cancer treatment.

Research on destructive knock combustion mechanism of heavy-duty diesel engine at low temperatures

ABSTRACT To clarify the mechanism of destructive knock combustion and piston ablation in heavy-duty diesel engines operating at low temperatures, CONVERGE simulation and wall temperature measurement were performed. The results show that as the initial temperature (intake valve closing instant) decreases from 380K to 307K, the spray wet-wall ratio increases from 12.8% to 22.2%. The fuel film evaporates slowly at low temperature before the hot flame, so the ignition is seriously delayed until the fuel injection ends, and the free-jet autoignition shifts to wall-attached combustion. However, the fuel film evaporation reverses after hot flame, and the maximum evaporation rate at 307K is about 54 times that at 380K. The wall temperature rises sharply to 350-450°C during wall-attached combustion. As the initial temperature decreases, the maximum pressure rise rate increases from 0.9MPa/°CA to 8.3MPa/°CA, and the pressure waves repeatedly oscillate along the end-center-end path in the cylinder. The highest pressure at the monitoring point is nearly an order of magnitude higher than the average, and the oscillation amplitude is as high as 6-10MPa, which far exceeds the failure threshold. The piston whose strength has been greatly reduced after thermal shock quickly undergoes ablation damage under strong pressure shock.

In Vivo Pathogenicity of Methicillin-Susceptible Staphylococcus aureus Strains Carrying Panton-Valentine Leukocidin Gene.

Toxin-producing Staphylococcus aureus strains posing a potential risk for public health have long been a topic of scientific research. Effects of Panton-Valentine leukocidin (PVL) on tissue destruction mechanisms and activities of inflammatory cells were presented in animal models of pneumonia and skin infections induced by PVL-producing S. aureus strains. This study aimed to demonstrate the in vivo pathogenicity of PVL-producing S. aureus strains isolated from some foodstuffs, which can be a potential risk to public health. PVL-positive methicillin-susceptible S. aureus (MSSA) strains M1 and YF1B-b isolated from different foodstuffs and a PVL-positive MSSA strain HT480 (positive control) were administered to New Zealand rabbits. Blood samples were harvested three and six hours after the intratracheal inoculation. Lung tissue samples were collected for gross and microscopic exams and immunohistochemical (IHC) demonstration of IL-6, IL8, IL-10, and TNF-α expressions. Serum cytokine levels were also measured by ELISA. The strains isolated from lung tissue samples were confirmed by pulsed-field gel electrophoresis. The development of acute necrotising pneumonia and a significant elevation in IL-6, IL-8, IL-10, and TNF-α expressions demonstrated the significance of foodborne PVL-positive MSSA strains in public health for the first time.

INFLUENCE OF HIGH TEMPERATURE TREATMENT ON THE MECHANICAL CHARACTERISTICS OF CARBON-CARBON COMPOSITE MATERIALS WITHPYROCARBON MATRIX

Pyrolytic compaction of porous substrates is one of the methods for obtaining carbon-carbon composite materials. When using such materials at high temperatures, for example, as elements of heaters, it is necessary to take into account the effect of high temperatures on their mechanical characteristics. In this work, the influence of high-temperature treatment on me-chanical characteristics was studied and the mechanism of destruction of samples of the mate-rial "Argolon GR" produced by JSC "Composite" was considered. It is shown that with an in-crease in the processing temperature from 1800 to 2400 °C, the open porosity of the samples increases in proportion to the increase in the number and size of cracks in the samples. The compressive failure stress depends very weakly on temperature, however, the graph of the corresponding dependence clearly shows its slight decrease with an increase in the processing temperature from 2000 to 2400 °C, which corresponds to the accumulation of damage in the material matrix that reduces its strength. Attention is drawn to a significant increase in the ten-sile strength of the material after high-temperature treatment, which is not typical for carbon-carbon composite materials. The dependence of the breaking stress in tension with an increase in the processing temperature for material samples has a pronounced maximum at 2000 °C. The analysis of the change in impact strength, the roughness parameter of the fracture surface of the samples, and the breaking stress in tension showed that the dominant mechanism during fracture is the mechanism of strength increase associated with the violation of the compatibility condition of deformations in the components of the material, while the effect of thermal stress relaxation is very small.

Research Progress and Prospect of Carbon Dioxide Utilization and Storage Based on Unconventional Oil and Gas Development

Energy security and the reduction of greenhouse gases such as carbon dioxide are two major crises facing the world today. Using carbon dioxide to develop unconventional oil and gas resources is a positive way to reduce greenhouse gas emissions, which can significantly alleviate global energy security issues. This study systematically introduces the prerequisites for CO2 to extract crude oil and CO2 to be safely and effectively stored. Under high temperature and high pressure, the rock properties of deep reservoirs are completely different from those of atmospheric conditions in the two-phase porous media environment of crude oil and high salinity formation water. The research progress on the phase behavior, mutual solubility, CO2 storage potential and mechanism between supercritical CO2 and crude oil, formation water and reservoir are reviewed in detail. In addition, CO2 leakage will inevitably occur during long-term geological storage, the proper estimation and evaluation of the risk and establishment of corresponding sealing methods are the way forward for CO2 geological storage. By systematically elaborating the nature, advantages and disadvantages of fluid–fluid, fluid–solid interaction and geological integrity destruction mechanism, the directions in which several key problems should be solved were pointed out.

Sedimentary and crustal structure of eastern North China from joint inversion of Rayleigh wave phase velocity and ellipticity and its implication for magmatism

Understanding the tectonic evolution of the North China Craton and its destruction mechanism requires the knowledge of eastern North China's fine crustal velocity structure. Using the two-year record of 342 ChinArray stations deployed in eastern North China, we obtain the Rayleigh wave phase velocity via ambient noise interferometry and Rayleigh wave ellipticity from ∼1000 teleseismic events. High-resolution sedimentary thickness and crustal 3D S-wave velocity structure are obtained by jointly inverting these observations. The results show that the Bohai Bay Basin is infilled with thick sediments and the Central Bohai Sea is the current depocenter with sedimentary thickness up to about 6 km. The crust and uppermost mantle beneath the Bohai Bay Basin are characterized by low velocity, indicating a high internal temperature of the crust. An upwelling of mantle thermal material under the crust of the Bohai Bay Basin continuously modifies the crust, suggesting that bottom-up thermochemical erosion is likely the primary control factor of crustal modification and thinning in this area. The uplift areas around the basin generally exhibit high velocity with weaker crustal modification, showing the heterogeneity of craton modification. Moreover, localized low-velocity zones observed beneath the Chifeng Volcanos, Dalainor Volcanos, and Kuandian Volcanos indicate the residual magmatism beneath these Quaternary volcanos. Furthermore, the magmatism beneath the Chifeng and Dalainor Volcanos shares a common magmatic source.

Rock Destruction Mechanisms under the Conditions of Multiple Metastable Defect-Induced States

Rock Destruction Mechanisms under the Conditions of Multiple Metastable Defect-Induced States

Polystyrene nanoplastics promote CHIP-mediated degradation of tight junction proteins by activating IRE1α/XBP1s pathway in mouse Sertoli cells

Microplastics (MPs) and nanoplastics (NPs) widely exist in human living environment and enter the body through water, food chain and breathing. Several studies have shown that MPs or NPs disrupt the blood-testis barrier in rodents. However, the molecular mechanism by which MPs and NPs damage the blood-testis barrier remains unclear. In the present study, our aim was to investigate the molecular mechanism of the destruction of blood-testis barrier induced by polystyrene (PS)-NPs. Mice were treated with 50 μg/kg·day PS-NPs by tail vein injection once daily for two consecutive days. The results showed that PS-NPs exposure significantly decreased the levels of tight junction (TJ) proteins ZO-2, occludin and claudin-11 in testis of mice. In vitro, we used TM4 Sertoli cells to explore the underlying mechanism of the decrease in TJ proteins induced by PS-NPs. We found that PS-NPs activated IRE1α and induced its downstream XBP1 splicing, which in turn elevated the expression of the E3 ubiquitin ligase CHIP, then CHIP triggers proteasomal degradation of ZO-2, occludin, and claudin-11 proteins. Our findings suggest that IRE1α/XBP1s/CHIP pathway is a pivotal mechanism of TJ proteins degradation induced by PS-NPs in mouse Sertoli cells. In conclusion, our results reveal that the degradation of TJ proteins is one of the mechanisms of blood-testis barrier destruction caused by acute exposure to PS-NPs.

Destruction of phosphorus nitride through the N(4S) + PN(1Σ+) → N2(1Σ+) + P(4S) reaction

ABSTRACT The study of reactions involving phosphorus bearing species (PBS) in star-forming regions as well as in circumstellar envelopes are important to elucidate the mechanisms in which this element is formed and destroyed, and perhaps, lead to important pre-biotic molecules. Phosphorus nitride (PN) is the most easily detected PBS in the interstellar medium (ISM), and is considered as one of the major reservoirs of this element in the ISM. However, only a few of its reactions have been analysed experimentally or computationally. Therefore, modelling PN chemistry and interpretation of the observations suffer uncertainties, affecting our astrochemical understanding of this species. In this work, we perform explicitly correlated multireference configuration interaction (MRCI+Q/AVTZ+d//CAS/AVTZ+d) calculations on the destruction of PN through the N(4S) + PN(1Σ+) reaction. We have also performed DFT (M06-2X) and CCSD(T) calculations for benchmark purposes. Rate coefficients over a large range of temperatures were computed using standard transition state theory (TST), canonical variational TST (CVT), and also incorporating tunneling effects with the small curvature tunneling method (SCT). We found that the NPN system possesses a considerable multireference character, and the DFT approach cannot properly describe the available destruction mechanisms. Our best estimate for the rate coefficients, at the MRCI+Q/AVTZ+d level, can be described by the modified Arrhenius equation 1.09×10−11(T/300)−1.02exp (− 7919/T). We show for the first time that this reaction may be considerably fast in shock regions and in high temperature environments of solar-type star forming regions, and of significant importance to model the abundance of PN in such environments.

A Study on the Influence of Bolt Arrangement Parameters on the Bending Behavior of Timber–Steel Composite (TSC) Beams

The present paper investigates the impact of bolt distance, bolt diameter, and the number of bolt rows on the bending performance of timber–steel composite (TSC) beams. This study aims to facilitate the application of bolt connections in assembled TSC structures. Composite steel I-beams were designed with timber boards connected in the upper section with bolts. Three-point static bending tests were conducted on nine timber–steel composite beams divided into four groups (L1, L2, L3, and L4) with varying bolt arrangements. The destruction mode, ultimate bearing capacity, ductility coefficient, load–midspan deflection curve, and load–midspan strain curve of each specimen were obtained. In addition, the destruction mechanism, the quantitative relationship between the bolt area ratio and interfacial slip, and the ideal bolt area ratio were identified. It was found that when the midspan deflection of the timber–steel composite beam approached the prescribed limit, the main failure mode can be explained as follows: The top surface of the boards of all the specimens had longitudinal local splitting, except L1, which had fewer bolts and no obvious damage. Moreover, due to compression and because the stress at the lower edge of the I-beam entered the flow amplitude stage, some of the specimens were crushed but were not pulled off. The composite beams had high flexural load capacity and ductility coefficient, and the maximum relative slips of the timber–steel interfaces were in the range of 2–6 mm. It was also found that the maximum slip of the interface and the ductility coefficient decreased steadily as the bolt area ratio increased, while the specimen’s flexural bearing capacity increased. The optimal bolt area ratio was determined to be 8 × 10−3. Using the total bolt area, we designed the arrangement of the bolts on the board. For convenience, multiple bolt variables were converted into one bolt variable. The longitudinal distance of the bolts had a greater impact on the slip, and the bolt diameter had a smaller impact. The theoretical values of total relative slip were found to be in good agreement with the experimental results, which were based on the superposition of the relative slip equations with varying bolt distances. The effective bolt area ratio and the formula of the relative slip of each segment can provide instructions for the arrangement of bolts and the control of the relative slip of intersections in engineering practices.

Mechanical destruction using a minimally invasive Ultrasound Needle induces anti-tumor immune responses and synergizes with the anti-PD-L1 blockade

Immune checkpoint inhibitors (ICIs) have been widely used in treating various tumors; however, the objective response rate of ICIs is less than 40%. In this study, we attempted to induce anti-tumor immune responses using an improved ultrasonic horn device, Ultrasound Needle (UN). We tested its synergistic anti-tumor efficacy with an anti-PD-L1 antibody in a mouse tumor model. Under different parameters, UN treatment selectively induced mechanical destruction and thermal ablation effects on tumor tissues. The mechanical destruction effect of UN treatment increased the infiltration of CD8+ T cells in tumors and relieved the immunosuppressive tumor microenvironment. It also induced systemic anti-tumor immune responses and enhanced the therapeutic efficacy of the anti-PD-L1 antibody in both local and abscopal tumors. The mechanical destruction effect of UN treatment resulted in the release of damage-associated molecular patterns and promoted dendritic cells (DCs)-based antigen presentation. Depletion of DCs or CD8+ T cells eliminated the anti-tumor immune responses induced by UN treatment and weakened the synergistic anti-tumor efficacy with anti-PD-L1 antibody. Therefore, minimally invasive UN may provide a new therapeutic modality for ultrasound-assisted immunotherapy.

A Multi-centre, Single Arm, Non-randomized, Prospective European Trial to Evaluate the Safety and Efficacy of the HistoSonics System in the Treatment of Primary and Metastatic Liver Cancers (#HOPE4LIVER)

PurposeImage-guided thermal ablation are established treatment options for non-surgical patients with primary and metastatic liver cancers. However, there are limitations with nonuniformity of cancer tissue destruction, heat sink effect and the risk of thermal ablative injury. The current non-thermal ablative techniques have high risk of local recurrence and are not widely adopted. Histotripsy is a treatment technology that destroys targeted tissue under ultrasound visualization via mechanical destruction through the precise application of acoustic cavitation and can offer the potential of non-invasive, non-thermal and non-ionizing radiation cancer treatment. The aim of this multi-centre non-randomized phase I/II trial is to assess the initial safety and efficacy of the prototype investigational ‘System’ in the treatment of primary and metastatic liver cancers.Methods/DesignAll non-surgical patients with primary/metastatic liver cancers having had previous liver directed therapy, radiation therapy or image-guided ablation may be offered image-guided Histotripsy as per trial protocol. The co-primary endpoints are technical success and procedural safety. Technical success is determined, at ≤ 36 h post procedure, by evaluating the histotripsy treatment size and coverage. The procedural safety is defined by procedure related major complications, defined as Common Terminology Criteria for Adverse Events (CTCAE version 5) grade 3 or higher toxicities, up to 30 days post procedure. This phase I/II trial has intended to recruit up to 45 patients to show safety and efficacy of image-guided histotripsy in liver cancers.Trail RegistrationClinicaltrials.gov identifier-NCT04573881; NIHR CRN CPMS-ID 47572.

Multi-Omics Analysis of Human Mesenchymal Stem Cell Guides Perinatal MSC Based Cellular Therapy for Splenectomy-Nonresponsive Refractory Immune Thrombocytopenia: A Phase I Clinical Trial

Mesenchymal stem cells (MSCs) are a heterogeneous population with the capacities of self-renewal, tissue regeneration and immunoregulation, which have attracted intensive attention for their potential application in the treatment of various immune disorders. However, the immunosuppressive efficacy of these therapies based on MSC products has not been thoroughly characterized, which may lead to inconsistent outcomes of MSC therapy in clinical trials. Cellular senescence is a state that imposes permanent proliferative arrest on cells in response to various types of stress and damage. Evidence suggests that aging MSCs tend to have a compromised immunosuppressive capability for inhibiting T cells. However, the underlying cellular and molecular mechanisms are poorly understood. It is also unknown whether the proportions and states of senescent cells in MSC products derived from various donors and different culture passages is associated with dissonant outcomes across clinical trials of MSC therapies. Immune thrombocytopenia (ITP) is an autoimmune disease characterized by immune-mediated destruction of circulating platelets (PLTs) and suppression of PLT production. It has been reported that autoantibody-coated PLTs undergo accelerated clearance through the spleen macrophage. However, anti-PLT antibodies are detected in less than 50% of patients, which raises the possibility of alternative mechanisms of PLT destruction. In line with this, splenectomy, which removes the primary site of PLT destruction and inhibits B-cell-mediated autoantibody production, has been shown to be the most effective therapy for steroid-refractory or steroid-dependent ITP and offers the highest rate of durable response (60% to 70%) compared with other therapies. Nevertheless, 30% to 40% of refractory ITP patients still show no response to splenectomy, indicating a B-cell-independent pathogenic mechanism. Abnormal function of T cells has been reported in ITP patients, which could collectively drive the autoimmune process. Therefore, the immune mechanism underpinning ITP should be further investigated. Additionally, it is of great value to explore new therapeutic options, such as MSC-based cellular therapy, especially for splenectomy-nonresponsive refractory ITP. Here, we performed a single-cell transcriptomic analysis of clinically used MSCs derived from adipose tissue (AD), the bone marrow (BM), the placental chorionic membrane (PM) and the umbilical cord (UC). The transcriptomic profiles of a total of 45,955 cells revealed an unprecedented level of heterogeneity in cellular senescence. We found that cultured MSCs underwent progressive cell aging, accompanied by the gradual loss of immunosuppressive function. Moreover, compared to adult MSCs (derived from AD and the BM), perinatal MSCs (derived from the PM and UC) had fewer aging cells and exhibited more potent suppressive activity. Mechanistically, we found that the impaired immunomodulatory function of senescent MSCs was associated with reduced expression of the immunosuppressive surface molecule PD-L1, which was demonstrated to be crucial for mediating the immunosuppressive activity of MSCs. Next, we performed single-cell transcriptome analysis and revealed that T-cell hyperactivation was evident in a cohort of refractory ITP patients who had no long-lasting remission after splenectomy. We therefore conducted the registered clinical trial (NCT04014166) of the use of UC-derived MSCs for refractory ITP. In this single-center, phase I trial, six refractory ITP patients received four rounds of three different doses of UC-derived MSC transfusions (0.5 × 106 MSCs/kg, n = 3; 1.0 × 106 MSCs/kg, n = 2; 2.0 × 106 MSCs/kg, n = 1). Notably, all three participants who received 1.0 × 106 or 2.0 × 106 MSCs/kg responded to the transfusions, with a manageable safety profile, while all three participants who received 0.5 × 106 MSCs/kg had no response to the transfusions. Our findings reveal the pivotal roles of cell aging and PD-L1 expression in determining the immunosuppressive efficacy of MSCs and demonstrate that PD-L1 abundant perinatal MSCs are effective in treating refractory ITP with T cell hyperactivation. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Rapamycin Inhibits Cytotoxic T Lymphocytes-Mediated Platelet Destruction in Immune Thrombocytopenia

Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized with increased risk of bleeding. CD8+ cytotoxic T lymphocytes (CTLs) of ITP patients express high level of lethal molecules, leading to the lysis and apoptosis of their own platelets, which is an important mechanism of platelet destruction in ITP patients. Accumulating evidence have highlighted that the activation of mTOR signaling pathway promotes the differentiation of CD8+ T cells to CTLs, which leads to the up-regulation of cell-mediated immunity. Several studies have showed that rapamycin, a mTOR inhibitor, was effective in the treatment of relapsed/refractory ITP. However, the endogenous mechanism remains to be explored. The activation of mTOR signaling pathway in CD8+ T cells was determined by flow cytometry. We found that the phosphorylation level of p-mTOR, p-Akt, p-4E-BP1 and p-P70S6K in ITP patients were significantly higher than that in healthy controls. Meanwhile, we found that the levels of perforin and granzyme B in CD8+ T cells in ITP patients were significantly higher than that in healthy controls. In the in vitro experiments, CTLs were isolated from PBMCs of ITP patients or healthy controls and cultured with different concentrations of rapamycin (0-1 uM) for 3 days, and we chose an optimal concentration of 20 nM. There was no significant difference in the expression levels of mTOR, Akt, 4E-BP1, and P70S6K after rapamycin treatment, but the phosphorylation level of p-mTOR, p-Akt, p-4E-BP1, p-P70S6K was significantly inhibited by rapamycin treatment. Likewise, the ratios of p-mTOR/mTOR, p-AKT/AKT, p-4E-BP1/4E-BP1, p-P70S6K/P70S6K were also significantly down-regulated. Flow cytometry analysis found that rapamycin significantly inhibited the expression of perforin and granzyme B (Figure 1) in CD8+ T cells of ITP patients. We further established the ITP murine model by transferring splenocytes of C57BL/6 CD61 knockout mice, immunized against platelets from wild-type syngeneic C57BL/6 mice, into severe combined immune deficient (SCID) mice. Rapamycin was injected intraperitoneally daily at a final concentration 2.0 mg/kg. Our data showed that the rapamycin group had significantly higher platelet counts compared with control group. In summary, our findings suggest that the activation of mTOR signaling pathway-related molecules of CD8+ T cells in patients with ITP are abnormal. These data shed new light on the molecular mechanism of rapamycin action by inhibiting CTLs cytotoxicity. This novel mechanism of rapamycin underlies the potential therapeutic strategy for ITP. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

CD8+ TEMRA Clones Cause Platelet Lysis in Immune Thrombocytopenia

Background Immune thrombocytopenia (ITP) is traditionally thought of as an antibody-mediated disease. However, there are a number of features to suggest alternative mechanisms of platelet destruction. In this study we use a multi-dimensional approach to explore the role of terminally differentiated effector memory CD8+ T cells (TEMRA). Methods We characterised 83 adults with chronic ITP and 30 age-matched controls using immunophenotyping, next generation sequencing of T cell receptor (TCR), single cell (sc) RNA sequencing and functional assays. Next generation DNA sequencing of TCRβ was carried out using the Illumina MiSeq platform. Analysis of the raw TCR sequences was performed using MiXCR. Single cell immune profiling (Gene expression and TCR) was done using Chromium Single Cell V(D)J and 5' Library kits from 10x Genomics. The constructed library was sequenced on the HiSeq platform (Illumina). Seurat v.2.3.4 was used for gene expression analysis. Interactions between CD8+ T cells and platelets were measured by co-culturing CD8+ T cells with autologous platelets overnight and by perfusing them on the autologous platelet covered VenaFluoro8+ microchip channel. Results We found an expansion of CD8+ CD45RA+ CD62L- TEMRA cells expressing IFN gamma, TNF alpha and granzyme B, with no evidence of physiological exhaustion (failure to upregulate TIM-3 or PD-1 expression) in ITP patients which correlated with disease activity. DNA TCR sequencing revealed that expansion of TEMRA cells in ITP was associated with reduced T cell repertoire diversity (p ≤ 0.0001) and lower Simpson's diversity index (p ≤ 0.05). Patients with ITP had a higher number of T cell clones occupying more than 5% of the T cell repertoire when compared to age matched controls (p ≤ 0.05). Expanded clones were not shared across ITP patients and displayed no known antigen specificities when compared to available databases of TCR sequences, providing evidence for the lack of virally driven clonal expansion. Clonally expanded CD8+ T cells persisted over many years in ITP patients and characterised disease severity. Longitudinal samples from 9 patients showed expanded clones and reduced T cell repertoire diversity during active disease (platelet count of less than 30 x 109/L) compared to stable disease (platelet count greater or equal to 30 x 109/L) (p ≤ 0.01; r = 0.56 - Figure 1 shows an example patient). To better characterise CD8+ T cells, we performed paired scRNA and scTCR sequencing on isolated whole CD8+ T cells from patients with active and stable disease. Paired sequencing enables transcriptomic characterisation of T cell clones. ScRNA sequencing revealed four distinct clusters in CD8+ T cells: naïve, TEMRA, central memory (CM) and natural killer T cells (NKT). By mapping scTCR CD8+ sequencing to single cell gene expression, we found that the largest expanded clones showed an aggregative distribution, indicating transcriptional homogeneity and were almost exclusively comprised of TEMRA cells (Figure 2). Consistent with immunophenotyping and DNA TCR sequencing, expanded TEMRA cell clones were expanded in active disease compared to stable disease. To assess the impact of these CD8+ T cells on platelets in ITP, PBMCs from patients with ITP and HC were passed across a platelet layer at flow rates consistent with venous blood flow. CD8+ T cells in ITP patients interacted with platelets 4x more frequently than HCs. Isolated CD8+ T cells were cultured over night with autologous platelets to further explore these interactions: CD8+ T cell:platelet aggregates were identified more frequently in the co-cultures from patients with ITP (p ≤ 0.05) and were inhibited by blocking MHC Class I (p ≤ 0.01). CD8+ T cells within the aggregates had increased CD107a expression compared to non-aggregated CD8+ T cells (p ≤ 0.01), indicating cytolytic activity and release of Granzyme and Perforin. Correspondingly, platelets in the aggregates showed increased CD62P expression, a marker of activation and impending death (p ≤ 0.001). Conclusions Here we demonstrate clonal expansion of disease-associated TEMRA CD8+ T cells in ITP. These cells bind to platelets and cause TCR-mediated platelet activation and death providing an antibody-independent mechanism of platelet destruction. This could serve as biomarker to direct treatment in patients with refractory ITP and targeting specific T-cell clones could be a novel therapeutic option in refractory ITP. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Immunotyping of ITP Based on Different Platelet Destruction Mechanism Are Associated with Response to Splenectomy

In recent years, although the long-term remission rate of splenectomy is comparable to or even higher than that of other second-line treatments, the usage rate of splenectomy in patients with ITP has decreased year by year due to concerns about postoperative complications and uncertainty about the efficacy. Therefore, in this study, we constructed an immune atlas of peripheral blood and spleen form patients who underwent splenectomy by single-cell immune repertoire sequencing. By comparing the immune status of preoperative peripheral blood and intraoperative spleen tissue from the patients with response and non-response to splenectomy, we found activation, function and ISG response-related gene sets were enriched in each B subset in the peripheral blood and spleen from patients with response to splenectomy. Accordingly, BAFF and APRIL signaling between MCs and B cells were enhanced in these patients, which result in B cell hyperfunction and the production of autoantibodies. These results suggested that their platelets were destroyed primarily by antibody-mediated manner in patients with response to splenectomy. Instead, gene sets related to activation, function and cytotoxicity were enriched in T and NK cells in the peripheral blood and spleen from patients without response to splenectomy, and the MHC-I score of MCs was up-regulated in these patients, suggesting that their platelets mainly lysis by cytotoxic T cells. Thus, we further detected antibody-mediated and CTL-mediated platelet destruction associated immune indictors by flow cytometry and ELISA, the results showed anti-GPIIbIIIa titer was higher, while Ts percentage, CD8+/CD4+ and Th1/Th2 ratio were lower in preoperative peripheral blood from patients with response than those from patients without response. ROC analysis showed that the latter three indicators could effectively classify patients with antibody-mediated and CTL-mediated ITP, thus predicted splenectomy efficacy. In addition, by comparing the immune profiles of patients before and after splenectomy, it was found that the proportion of B cells in peripheral blood decreased after splenectomy, but the activation functions of B and T cells were significantly enhanced, which may partially compensate for the loss of humoral immunity caused by splenectomy. Therefore, the risk of long-term infection after operation may be lower than expected. We proceeded follow-up the ITP patients with (n=85) or without splenectomy(n=50) in our center in last 8 years and found that the infection rate of splenectomy patients was 5.88%, and that of non-operated patients was 12%, which confirmed our speculation. In conclusion, our study found that splenectomy had satisfactory clinical efficacy in patients with antibody-mediated platelet destruction, and the risk of long-term postoperative infection was not significantly increased compared with patients with ITP who did not undergo splenectomy.

Deciphering the disturbance mechanism of BaP on the symbiosis of Montipora digitata via 4D-Proteomics approach

The coral holobiont is mainly composed of coral polyps, zooxanthellae, and coral symbiotic microorganisms, which form the basis of coral reef ecosystems. In recent years, the severe degradation of coral reefs caused by climate warming and environmental pollution has aroused widespread concern. Benzo(a)pyrene (BaP) is a widely distributed pollutant in the environment. However, the underlying mechanisms of coral symbiosis destruction due to the stress of BaP are not well understood. In this study, diaPASEF proteomics and 16S rRNA amplicon pyrosequencing technology were used to reveal the effects of 50 μg/L BaP on Montipora digitate. Data analysis was performed from the perspective of the main symbionts of M. digitata (coral polyps, zooxanthellae, and coral symbiotic microorganisms). The results showed that BaP impaired cellular antioxidant capacity by disrupting the GSH/GSSG cycle, and sustained stress causes severe impairment of energy metabolism and protein degradation in coral polyps. In zooxanthellae, BaP downregulated the protein expression of SOD2 and mtHSP70, which then resulted in oxidative free radical accumulation and apoptosis. For coral symbiotic microorganisms, BaP altered the community structure of microorganisms and decreased immunity. Coral symbiotic microorganisms adapted to the stress of BaP by adjusting energy metabolism and enhancing extracellular electron transfer. BaP adversely affected the three main symbionts of M. digitata via different mechanisms. Decreased antioxidant capacity is a common cause of damages to coral polyps and zooxanthellae, whereas coral symbiotic microorganisms are able to appropriately adapt to oxidative stress. This study assessed the effects of BaP on corals from a symbiotic perspective, which is more comprehensive and reliable. At the same time, data from the study supports new directions for coral research and coral reef protection.

Monitoring of grinding condition in drum mills based on resulting shaft torque

Grinding is the most energy-intensive process among all stages of raw material preparation and determines the course of subsequent ore beneficiation stages. Level of electricity consumption is determined in accordance with load characteristics forming as a result of ore destruction in the mill. Mill drum speed is one of process variables due to which it is possible to control ore destruction mechanisms when choosing speed operation mode of adjustable electric mill drive. This study on increasing energy efficiency due to using mill electric drive is based on integrated modelling of process equipment – grinding process and electromechanic equipment – electric drive of grinding process. Evaluating load torque by means of its decomposition into a spectrum, mill condition is identified by changing signs of frequency components of torque spectrum; and when studying electromagnetic torque of electric drive, grinding process is monitored. Evaluation and selection of efficient operation mode of electric drive is based on the obtained spectrum of electromagnetic torque. Research results showed that with increasing mill drum speed – increasing impact energy, load torque values are comparable for the assigned simulation parameters. From the spectra obtained, it is possible to identify mill load condition – speed and fill level. This approach allows evaluating the impact of changes in process variables of grinding process on parameters of electromechanical system. Changing speed operation mode will increase grinding productivity by reducing the time of ore grinding and will not lead to growth of energy consumption. Integration of digital models of the technological process and automated electric drive system allows forming the basis for developing integrated methods of monitoring and evaluation of energy efficiency of the entire technological chain of ore beneficiation.

Atomistic study of nano-cutting bicrystal cubic silicon carbide

To solve problems of low machining efficiency and surface/subsurface damage of silicon carbide (SiC), mechanisms of material dislodging and subsurface destruction of bicrystal SiC under nano-cutting were studied by using three-dimensional molecular dynamics (MD) simulation method. Effects of grain boundary (GB) tilt angle and cutting speed on stress, hydrostatic pressure, cutting force, temperature, and subsurface damage depth were analyzed. Results show that GB slope angle has important influence on the spread of strain, hydrostatic stress, and temperature, especially on subsurface damage depth. Specifically, with the increase in GB slope angle, subsurface damage layer decreases, and machined surface morphology improves. The machinability of small GB angle is better than the large GB angle, and the model with grain boundary angle of 4.24° has the best machinability. It is also found that with the increase in cutting velocity, the temperature increases, whereas cutting force and friction coefficient are reduced, which indicates that the increase in cutting velocity can effectively improve surface machined morphology. The research results provide a theoretical reference for future experimental research.