The load carriage is an important part of the conventional rail endless rope driven transport system aiming at the safety accidents such as derailment,descent and rollover caused by the vibration of ...the carriage in the process of transporting people or goods. In this paper,the vibration of the load carriage of the standard wheeling device and the clamp wheeling device are tested under three conditions: straight lanes,horizontal turning radius of 9 m,and vertical turning radius of 15 m. The analysis of the vibration performance of different gear trains under a variety of operating speeds shows that the clamp wheeling device has the best stability. With the increase of speed,when the running speed is more than 2. 0 m/s,the lateral amplitude of the standard wheeling device is larger; when the running speed is more than 1. 5 m/s,the longitudinal amplitude and the lateral amplitude of the standard wheeling device are larger than that of the clamp rail gear train,It is recommended to add the guard rail device; the
This paper proposes a nonparametric point cloud filter to address the issue that existing point cloud filtering methods cannot retain important point cloud features after filtering and often require ...complex parameter adjustments. Firstly, a nonparametric clustering method is proposed to cluster various features of the point cloud and filter out isolated outliers. Then, the manifold distance truncation method is adopted to remove the outlier cluster generated by the point cloud clustering to complete point cloud filtering. Additionally, the proposed nonparametric clustering algorithm is compared with four of the latest clustering algorithms, including K‐means clustering and OPTICS clustering to verify the rationality of the clustering features. Finally, the filtering results of the nonparametric point cloud filter are compared with those of statistical filtering and two other recently proposed point cloud filters to demonstrate its improved filtering effect and algorithm stability. The experimental results indicate that the proposed nonparametric point cloud filter can achieve better‐filtering results and retain more point cloud features without adjusting parameters.
(1) By restoring weight from data, the difficulty in determining the initial parameters of the point cloud filter can be solved. (2) Using manifold distance instead of Euclidean distance can better retain the spatial characteristics of the point cloud. (3) The no‐gap test method can better cluster the characteristics of point clouds. This is significant because to solve the problems of incomplete feature retention and excessive parameters of point cloud filtering.
The Gangdese batholith emplaced during the time span of Cretaceous to Neogene in the southern Lhasa terrane of Tibet has been considered as a major constituent of an Andean-type convergent margin ...derived from the northward subduction of the Neo-Tethyan oceanic lithosphere under Asia. Whereas previous studies assigned the Gangdese granitoids to be comprised predominantly of calc-alkaline rocks, here we report a suite of charnockites from the eastern part of the belt and characterize their petrology, geochemistry and age. These rocks possess an assemblage of andesine, enstatite, diopside, calcic amphibole, Ti-rich biotite, quartz and minor K-feldspar. Geochemically, they are characterized by intermediate SiO
2 (54–63
wt.%), relatively high Al
2O
3 (15.9–18.9
wt.%), REE (55.7–89.4
ppm) and Sr (419.6–619.4
ppm), and low Y (11.3–17.2
ppm) and Yb (1.2–1.8
ppm) concentrations. The rocks display geochemical affinities similar to those of adakites derived from the partial melting of a subducted slab, and also can be compared to magnesian charnockites formed within a continental magmatic arc. The crystallization conditions of the charnockites were estimated at 900
°C and 1.0
GPa. LA-ICP-MS zircon U–Pb analyses of eleven samples yield consistent
206Pb/
238U weighted mean ages of 86 to 90
Ma, indicating that the charnockites were emplaced in the Late Cretaceous. Considering the coeval calc-alkaline magmatism and high-temperature granulite-facies metamorphism, we propose that such high-temperature and low-H
2O activity charnockites were derived through Neo-Tethyan mid-ocean ridge subduction before the collision of India with the Asian continent.
A limitation of using exosomes to their fullest potential is their limited secretion from cells, a major bottleneck to efficient exosome production and application. This is especially true for ...mesenchymal stem cells (MSCs), which can self-renew but have a limited expansion capacity, undergoing senescence after only a few passages, with exosomes derived from senescent stem cells showing impaired regenerative capacity compared to young cells. Here, we examined the effects of small molecule modulators capable of enhancing exosome secretion from MSCs. The treatment of MSCs with a combination of N-methyldopamine and norepinephrine robustly increased exosome production by three-fold without altering the ability of the MSC exosomes to induce angiogenesis, polarize macrophages to an anti-inflammatory phenotype, or downregulate collagen expression. These small molecule modulators provide a promising means to increase exosome production by MSCs.
A total of 40 fiber reinforced polymer (FRP) and polyvinyl chloride (PVC) confined spontaneous combustion gangue coarse-aggregate concrete (SAC) specimens were subjected to axial compression tests ...and theoretical studies. The main analysis focused on the impact of the replacement rate of spontaneous combustion gangue (SCG), the type of CFRP confinement, and the number of CFRP layers on the axial compression performance of CFRP-PVC confined SAC (CFRP-PVC-SAC). The results show that CFRP-PVC confinement can effectively enhance the axial compressive capacity, axial deformation, and lateral deformation of the components. The increase in strength ranges from 1.68 to 3.48 times, while the increase in strain ranges from 5.21 to 11.98 times. The crack patterns and expansive behavior of the coal gangue concrete under confinement exhibit significant differences compared to ordinary concrete. In addition, based on the framework of the existing FRP-confined plain concrete model, a modified model is established to facilitate prediction of stress-strain relationships for short columns of CFRP-PVC-SAC, with the calculated results in good agreement with experimental values.
The removal and installation time of airborne equipment, is not only an important maintainability design index, but also an important parameter to select or optimize the design scheme. A ...comprehensive evaluation method is presented, which is based on the process simulation model and integrates the evaluation results of maintenance complexity and maintenance ergonomics analysis. Firstly, the disassembly and installation process is decomposed into basic maintenance activities, and process simulation model is created. Then by using modolar arrangement of predetermind time standard (MODAPTS) the basic maintenance activities time is evaluated. Using the coefficient, which is determined by the comprehensive evaluation results of maintenance complexity and maintenance ergonomics analysis, the basic maintenance activities time is corrected. Finally, the disassembly and installation time is evaluated according to basic maintenance activities time and maintenance work process analysis. The method is verified by a case
Multiple sclerosis (MS) is an autoimmune, inflammatory demyelinating disorder of the central nervous system. Accumulating evidence has underscored the therapeutic potential of bone marrow mesenchymal ...stem cells (BMSCs)-derived exosomes (BMSC-Exos) containing bioactive compounds in MS. Herein, the current study sought to characterize the mechanism of BMSC-Exos harboring miR-367–3p both in BV2 microglia by Erastin-induced ferroptosis and in experimental autoimmune encephalomyelitis (EAE), a typical animal model of MS. Exosomes were firstly isolated from BMSCs and identified for further use. BV2 microglia were co-cultured with miR-367–3p-containing BMSC-Exos, followed by an assessment of cell ferroptosis. Mechanistic exploration was furthered by the interaction of miR-367–3p and its downstream regulators. Lastly, BMSC-Exos harboring miR-367–3p were injected into EAE mice for in vivo validation. BMSC-Exos carrying miR-367–3p restrained microglial ferroptosis in vitro. Mechanistically, miR-367–3p could bind to Enhancer of zeste homolog 2 (EZH2) and restrain EZH2 expression, leading to the over-expression of solute carrier family 7 member 11 (SLC7A11). Meanwhile, over-expression of SLC7A11 resulted in Glutathione Peroxidase 4 (GPX4) activation and ferroptosis suppression. Ectopic expression of EZH2 in vitro negated the protective effects of BMSC-Exos. Furthermore, BMSC-Exos containing miR-367–3p relieved the severity of EAE by suppressing ferroptosis and restraining EZH2 expression in vivo. Collectively, our findings suggest that BMSC-Exos carrying miR-367–3p brings about a significant decline in microglia ferroptosis by repressing EZH2 and alleviating the severity of EAE in vivo, suggesting a possible role of miR-367–3p overexpression in the treatment strategy of EAE.
The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.
•Mesenchymal stem cell-derived exosomes (BMSC-Exos) suppress microglial ferroptosis•BMSC-Exos carrying miR-367–3p inhibit microglial ferroptosis via EZH2/SLC7A11 axis.•BMSC-Exos carrying miR-367–3p alleviate the severity of experimental autoimmune encephalomyelitis.•The role of BMSC-Exos carrying miR-367–3p in experimental autoimmune encephalomyelitis may be through the regulation of EZH2/SLC7A11-mediated ferroptosis.
Diabetic Retinopathy (DR) is the leading cause of vision loss in working-age adults. The hallmark features of DR include vascular leakage, capillary loss, retinal ischemia, and aberrant ...neovascularization. Although the pathophysiology is not fully understood, accumulating evidence supports elevated reactive oxygen species associated with increased activity of NADPH oxidase 4 (Nox4) as major drivers of disease progression. Previously, we have shown that Nox4 upregulation in retinal endothelial cells by diabetes leads to increased vascular leakage by an unknown mechanism. Platelet endothelial cell adhesion molecule 1 (PECAM-1) is a cell surface molecule that is highly expressed in endothelial cells and regulates endothelial barrier function. In the present study, using endothelial cell-specific human Nox4 transgenic (TG) mice and endothelial cell-specific Nox4 conditional knockout (cKO) mice, we investigated the impact of Nox4 upregulation on PECAM-1 expression in mouse retinas and brain microvascular endothelial cells (BMECs). Additionally, cultured human retinal endothelial cells (HRECs) transduced with adenovirus overexpressing human Nox4 were used in the study. We found that overexpression of Nox4 increases PECAM-1 mRNA but has no effect on its protein expression in the mouse retina, BMECs, or HRECs. Furthermore, PECAM-1 mRNA and protein expression was unchanged in BMECs isolated from cKO mice compared to wild type (WT) mice with or without 2 months of diabetes. Together, these findings do not support a significant role of Nox4 in the regulation of PECAM-1 expression in the diabetic retina and endothelial cells. Further studies are warranted to elucidate the mechanism of Nox4-induced vascular leakage by investigating other intercellular junctional proteins in endothelial cells and their implications in the pathophysiology of diabetic retinopathy.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Mycobacterium tuberculosis is a hard-to-eradicate intracellular pathogen that infects one-third of the global population. It can live within macrophages owning to its ability to arrest phagolysosome ...biogenesis. Autophagy has recently been identified as an effective way to control the intracellular mycobacteria by enhancing phagosome maturation. In the present study, we demonstrate a novel role of miR-155 in regulating the autophagy-mediated anti-mycobacterial response. Both in vivo and in vitro studies showed that miR-155 expression was significantly enhanced after mycobacterial infection. Forced expression of miR-155 accelerated the autophagic response in macrophages, thus promoting the maturation of mycobacterial phagosomes and decreasing the survival rate of intracellular mycobacteria, while transfection with miR-155 inhibitor increased mycobacterial survival. However, macrophage-mediated mycobacterial phagocytosis was not affected after miR-155 overexpression or inhibition. Furthermore, blocking autophagy with specific inhibitor 3-methyladenine or silencing of autophagy related gene 7 (Atg7) reduced the ability of miR-155 to promote autophagy and mycobacterial elimination. More importantly, our study demonstrated that miR-155 bound to the 3'-untranslated region of Ras homologue enriched in brain (Rheb), a negative regulator of autophagy, accelerated the process of autophagy and sequential killing of intracellular mycobacteria by suppressing Rheb expression. Our results reveal a novel role of miR-155 in regulating autophagy-mediated mycobacterial elimination by targeting Rheb, and provide potential targets for clinical treatment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Uncertainty assessment is a common requirement in 3D modeling applications. The Markov chain Monte-Carlo (MCMC) method is a practical way to generate multiple realizations of 3D models to evaluate ...model uncertainty. However, when probing high-dimensional target distributions related to the detailed geometry of 3D geological interfaces, the generating 3D models by existing MCMC methods always suffer from the presence of artifacts in large geometrical deformation that modeling deformed geometries in stochastic perturbation, which limits their effectiveness and efficiency. This paper presents an abstract graph-based MCMC method for the uncertainty assessment of 3D geological interfaces. An abstract graph is used to represent the reasonable shape of the geological interface. In proposing new candidate 3D models via the MCMC iterations, the 3D models are perturbed such that the energy function measuring the distortion of the abstract graph is minimized in a least-squares sense. This can preserve the plausible geometry of the 3D models against high perturbations and provide artifact-free 3D models as candidates for MCMC sampling. The resulting MCMC iterations enable the drawing of probable realizations of 3D models while maintaining a high acceptance rate in probing the complicated target distributions of 3D geological interface models. The proposed method was applied to the assessment of uncertainties in three regional faults in the Jiaodong Peninsula, eastern China. The uncertainty assessment was carried out based on a complex probability distribution with consideration of geological-geophysical observations and prior knowledge of fault geometry. The results show that the proposed MCMC method could reasonably locate the uncertainties in free-form fault models defined by thousands of constraints. And the abstract graph-based MCMC method can sample highly-perturbed and geometrically plausible 3D models in high-resolution, which is crucial to the effectiveness and efficiency of the geometrical uncertainty assessment.
•An MCMC method for assessing detailed geometrical uncertainty in 3D models.•An MCMC method that can propose highly perturbed but artifact-free 3D models.•Effectively assessing uncertainty in detailed 3D models from posterior distribution.•Integrating observations and knowledge for uncertainty assessment of 3D models.
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