Glucocorticoid-induced expansion of classical monocytes contributes to bone loss

Liu Pei,Gao Youshui,Luo Pengbo,Yu Hongping,Guo Shang,Liu Fuyun,Gao Junjie,Xu Jianzhong,Wang Shengdian,Zhang Changqing 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Classical monocytes are commonly involved in the innate inflammatory response and are the progenitors of osteoclasts. Excess endogenous glucocorticoids (GCs) can increase the levels of classical monocytes in blood and bone marrow. The role of this cell population in high-dose exogenous GC-induced osteoporosis (GIOP) remains to be elucidated. In this study, GIOP was established in rats and mice by daily methylprednisolone injection, and monocyte subsets were analyzed by flow cytometry. We demonstrated that classical monocytes accumulate in bone marrow during GIOP. Similarly, the monocyte proportion among bone marrow nucleated cells was also increased in patients with steroid treatment history. We sorted classical monocytes and analyzed their transcriptional profile in response to GCs by RNA sequencing. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that classical monocytes isolated from GC-treated rats exhibited osteoclast differentiation potential. Deletion of classical monocytes by clodronate liposome treatment prevented GIOP via inhibition of osteoclastogenesis and restoration of CD31HiendomucinHi vessels. Regarding the molecular mechanism, classical monocytes express high levels of glucocorticoid receptors. In vitro treatment with GCs increased both the percentage and absolute number of monocytes and promoted their proliferation. In summary, classical monocytes mediated GC-induced bone loss and are a potential target for therapeutic intervention in GIOP treatment.

Regularization statistical inferences for partially linear models with high dimensional endogenous covariates

Liu Changqing,Zhao Peixin,Yang Yiping 한국통계학회 2021 Journal of the Korean Statistical Society Vol.50 No.1

In this paper, we consider the statistical inferences for a class of partially linear models with high dimensional endogenous covariates, when high dimensional instrumental variables are also available. A regularized estimation procedure is proposed for identifying the optimal instrumental variables, and estimating covariate efects of the parametric and nonparametric components. Under some conditions, some theoretical properties are studied, such as the consistency of the optimal instrumental variable identifcation and signifcant covariate selection. Furthermore, some simulation studies and a real data analysis are carried out to examine the fnite sample performance of the proposed method.

Recognition of rolling bearing fault patterns and sizes based on two-layer support vector regression machines

Changqing Shen,Dong Wang,Yongbin Liu,Peter W. Tse,Fanrang Kong 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.13 No.3

The fault diagnosis of rolling element bearings has drawn considerable research attention in recent years because these fundamental elements frequently suffer failures that could result in unexpected machine breakdowns. Artificial intelligence algorithms such as artificial neural networks (ANNs) and support vector machines (SVMs) have been widely investigated to identify various faults. However, as the useful life of a bearing deteriorates, identifying early bearing faults and evaluating their sizes of development are necessary for timely maintenance actions to prevent accidents. This study proposes a new two-layerstructure consisting of support vector regression machines (SVRMs) to recognize bearing fault patterns and track the fault sizes. The statistical parameters used to track the fault evolutions are first extracted to condense original vibration signals into a few compact features. The extracted features are then used to train the proposed two-layer SVRMs structure. Once these parameters of the proposed two-layer SVRMs structure are determined, the features extracted from other vibration signals can be used to predict theunknown bearing health conditions. The effectiveness of the proposed method is validated by experimental datasets collected from a test rig. The results demonstrate that the proposed method is highly accurate in differentiating between fault patterns and determining their fault severities. Further, comparisons are performed to show that the proposed method is better than some existing methods.

Comparison of overfed Xupu and Landes geese in performance, fatty acid composition, enzymes and gene expression related to lipid metabolism

Liu Xu,Li Peng,He Changqing,Qu Xiangyong,Guo Songchang 아세아·태평양축산학회 2020 Animal Bioscience Vol.33 No.12

Objective: The aim of this study was to compare overfeeding performance, fatty acid composition, blood chemistry, enzymes and genes expression overfed Xupu and Landes geese. Methods: Sixty male Xupu geese (80 d) and Landes geese (80 d) were selected. After a period of one-week of pre-overfeeding, Xupu and Landes geese were overfed three meals of 550 and 350 g/d, respectively, of a high-carbohydrate diet in the first week of the overfeeding period. The next week, geese were given four meals of 1,200 and 850 g/d, respectively, over 8 to 14 d. Finally, geese were given five meals of 1,600 and 1,350 g/d, respectively, for the last two weeks. Results: After overfeeding for 28 d: Compared with Landes geese, Xupu geese liver weight and liver-to-body weight ratio decreased (p<0.05), while final weight, slaughter weight, total weight gain, abdominal fat weight, and feed-to-liver weight ratio increased (p<0.05). The levels of elaidic acid (C18:1t9), oleic acid (C18:1n-9), eicosenoic acid, and arachidonic acid in the liver of Xupu geese significantly increased (p<0.05), and the levels of myristic acid and stearic acid significantly decreased (p<0.05), while methyleicosanoate acid significantly increased (p<0.05). Xupu geese had higher plasma concentrations of triglyceride and very low density lipoprotein cholesterol (p<0.05), and decreased activities of alanine aminotransferase, aspartate aminotransferase, and lipase (LPS) (p<0.05). Landes geese had higher LPS activity (p<0.05), but lower cholinesterase activity (p<0.05) when compared with Xupu geese. The mRNA expression levels of fatty acid dehydrogenase (FADS) gene, elongase of long-chain fatty acid 1 (ELOVL1) gene, ELOVL5, and acyl-Co A: cholesterol acyltransferase 2 (ACAT2) gene were significantly upregulated (p<0.05) in Landes goose when compared with Xupu geese. Conclusion: This study demonstrates that the liver production performance of Landes geese was better than that of Xupu geese to some extent, which may be closely related to LPS activity, as well as the expression of FADS, ELOVL1, ELOVL5, and ACAT2.

The catalytic core of DEMETER guides active DNA demethylation in <i>Arabidopsis</i>

Zhang, Changqing,Hung, Yu-Hung,Rim, Hyun Jung,Zhang, Dapeng,Frost, Jennifer M.,Shin, Hosub,Jang, Hosung,Liu, Fang,Xiao, Wenyan,Iyer, Lakshminarayan M.,Aravind, L.,Zhang, Xiang-Qian,Fischer, Robert L. National Academy of Sciences 2019 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.116 No.35

<P><B>Significance</B></P><P>Flowering plants reproduce via a unique double-fertilization event, producing the zygote and the nutritive endosperm. The genome of the central cell, the precursor of the endosperm, undergoes extensive demethylation prior to fertilization. This epigenetic reconfiguration, directed by the DEMETER (DME) glycosylase at thousands of loci in <I>Arabidopsis</I>, differentiates the epigenetic landscapes of parental genomes and establishes parent of origin-specific expression of many imprinted genes in endosperm essential for seed development. However, how DME is targeted to various locations remains unknown. Here we show that the multidomain DME is organized into 2 functional regions: the C-terminal region, which guides localization and catalysis, and the N-terminal region, which likely recruits chromatin remodelers to facilitate demethylation within heterochromatin.</P><P>The <I>Arabidopsis</I> DEMETER (DME) DNA glycosylase demethylates the maternal genome in the central cell prior to fertilization and is essential for seed viability. DME preferentially targets small transposons that flank coding genes, influencing their expression and initiating plant gene imprinting. DME also targets intergenic and heterochromatic regions, but how it is recruited to these differing chromatin landscapes is unknown. The C-terminal half of DME consists of 3 conserved regions required for catalysis in vitro. We show that this catalytic core guides active demethylation at endogenous targets, rescuing <I>dme</I> developmental and genomic hypermethylation phenotypes. However, without the N terminus, heterochromatin demethylation is significantly impeded, and abundant CG-methylated genic sequences are ectopically demethylated. Comparative analysis revealed that the conserved DME N-terminal domains are present only in flowering plants, whereas the domain architecture of DME-like proteins in nonvascular plants mainly resembles the catalytic core, suggesting that it might represent the ancestral form of the 5mC DNA glycosylase found in plant lineages. We propose a bipartite model for DME protein action and suggest that the DME N terminus was acquired late during land plant evolution to improve specificity and facilitate demethylation at heterochromatin targets.</P>

Influence of Polyurethane Polymer on the Strength and Mechanical Behavior of Sand-root Composite

Jin Liu,Zhihao Chen,Zhaojun Zeng,Debi Prasanna Kanungo,Fan Bu,Yuxia Bai,Changqing Qi,Wei Qian 한국섬유공학회 2020 Fibers and polymers Vol.21 No.4

Vegetation has good application in slope stabilization, but its beneficial effects on reinforcing topsoil are generallylimited by the soil properties it was cultivated in. This study aims at evaluating the strength improvements of sand-rootcomposite by treating with polyurethane polymer and hence investigating the mechanism of polymer-root-soil interactions. Vegetation roots were selected and mixed with dry sand and polymer solution to prepare remolded specimens. A series ofexperimental tests were then performed at different percentages of root content (0, 0.4, 0.8, 1.2, and 1.6 % by weight of drysand) and polymer content (1, 2, and 4 % by weight of dry sand) to evaluate the shear parameters and unconfinedcompressive strength (UCS). The combined mechanism was studied by scanning electron microscopy (SEM) images. Theresults showed that the strengthening effect has greater efficiency with higher polymer content. Through varying contents ofvegetation root, it was found that low root content induced an undesirable weakening effect on the strength of the treated soil. However, this situation was somewhat improved with the increase in root content. The good flexibility of polymers not onlypromote the capacity of soil to energy absorption, but also impart good ductility to soil. The presence of polymers greatlystrengthens soil stability due to its special network structure, by which the improved shear resistance at the root-soil interfaceprovides sufficient anchorage effect for the tensile strength of roots to be fully mobilized. Overall, the synergistic effect ofroot reinforcement and polymer treatment has the potential for its use in soil stabilization.

Recognition of rolling bearing fault patterns and sizes based on two-layer support vector regression machines

Shen, Changqing,Wang, Dong,Liu, Yongbin,Kong, Fanrang,Tse, Peter W. Techno-Press 2014 Smart Structures and Systems, An International Jou Vol.13 No.3

The fault diagnosis of rolling element bearings has drawn considerable research attention in recent years because these fundamental elements frequently suffer failures that could result in unexpected machine breakdowns. Artificial intelligence algorithms such as artificial neural networks (ANNs) and support vector machines (SVMs) have been widely investigated to identify various faults. However, as the useful life of a bearing deteriorates, identifying early bearing faults and evaluating their sizes of development are necessary for timely maintenance actions to prevent accidents. This study proposes a new two-layer structure consisting of support vector regression machines (SVRMs) to recognize bearing fault patterns and track the fault sizes. The statistical parameters used to track the fault evolutions are first extracted to condense original vibration signals into a few compact features. The extracted features are then used to train the proposed two-layer SVRMs structure. Once these parameters of the proposed two-layer SVRMs structure are determined, the features extracted from other vibration signals can be used to predict the unknown bearing health conditions. The effectiveness of the proposed method is validated by experimental datasets collected from a test rig. The results demonstrate that the proposed method is highly accurate in differentiating between fault patterns and determining their fault severities. Further, comparisons are performed to show that the proposed method is better than some existing methods.

Deformation Mechanism of 5052 Aluminum Alloy Using Electrically Assisted Electromagnetic Forming

Ang Xiao,Changqing Huang,HongSheng Liu,Xiaohui Cui,Shipeng Wang 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.10

A technology named as electrically assisted electromagnetic forming (EAEMF) was used to improve the plastic deformationability of 5052 aluminum alloy at room temperature. The ANSYS software is used to study the force and deformation ofworkpiece based on sequential coupling method. The simulation results show that the pulse current can increase the currentdensity, improve the uniformity of current distribution, and increase the forming height of the sample. The primary strainand secondary strain are increased by 53.8% and 27.4% respectively. Under the same deformation condition, the elongationof EAEMF sample increases by 160%, while the strength decreases slightly. From the perspective of microstructure evolution,the dislocation density of EAEMF sample is lower than that of EMF sample, and the pinning effect of the second phaseparticles on the dislocation is weakened. Under the action of the pulse current, the dislocations continue to move around thesecond phase particles with higher energy, and the dislocations appear directional arrangement.

The Study on the Stress and Photo-Oxidative Aging of Polyethylene Cable Sheath Under Different Processing Conditions

Wenxuan Hu,Changqing Liu,Wenjun Liu,Xiancheng Ren 한국고분자학회 2018 Macromolecular Research Vol.26 No.5

High-density polyethylene (HDPE) materials were processed into specimens under different processing conditions in this paper. Then specimens were aged under stress and ultraviolet (UV) light in an aging box, and the aging behaviors were studied by means of surface morphology observation, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). It was found that the aging properties of sheath materials were associated with the crystallinity of surface layer. Samples in lower extrusion temperature system and higher extrusion rate had lower surface layer crystallinity and better antiaging properties. In addition, the stress and photo-oxidative aging mechanism were explored. There were two stages in the stress and photo-oxidative aging, which was reflected in the surface layer that crystallinity increased firstly and then decreased. This study may provide better processing conditions for cable sheath materials.

Assessment of the Cytotoxic and Apoptotic Effects of Chaetominine in a Human Leukemia Cell Line

Yao, Jingyun,Jiao, Ruihua,Liu, Changqing,Zhang, Yupeng,Yu, Wanguo,Lu, Yanhua,Tan, Renxiang The Korean Society of Applied Pharmacology 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.2

Chaetominine is a quinazoline alkaloid originating from the endophytic fungus Aspergillus fumigatus CY018. In this study, we showed evidence that chaetominine has cytotoxic and apoptotic effects on human leukemia K562 cells and investigated the pathway involved in chaetominine-induced apoptosis in detail. Chaetominine inhibited K562 cell growth, with an $IC_{50}$ value of 35 nM, but showed little inhibitory effect on the growth of human peripheral blood mononuclear cells. The high apoptosis rates, morphological apoptotic features, and DNA fragmentation caused by chaetominine indicated that the cytotoxicity was partially caused by its pro-apoptotic effect. Under chaetominine treatment, the Bax/Bcl-2 ratio was upregulated (from 0.3 to 8), which was followed by a decrease in mitochondrial membrane potential, release of cytochrome c from mitochondria into the cytosol, and stimulation of Apaf-1. Furthermore, activation of caspase-9 and caspase-3, which are the main executers of the apoptotic process, was observed. These results demonstrated that chaetominine induced cell apoptosis via the mitochondrial pathway. Chaetominine inhibited K562 cell growth and induced apoptotic cell death through the intrinsic pathway, which suggests that chaetominine might be a promising therapeutic for leukemia.