Fabrication and Magnetic Properties of A New Fe-based Amorphous Compound Powder Cores

Xiangyue Wang,Deren Li,Caowei Lu,Feng Guo,Zhichao Lu,Shaoxiong Zhou 한국자기학회 2010 한국자기학회 학술연구발표회 논문개요집 Vol.2010 No.12

CXCL12 secreted by pancreatic stellate cells accelerates gemcitabine resistance of pancreatic cancer by enhancing glycolytic reprogramming

Xiangyu Lu,Yilei Wu,Rui Cao,Xiaojiong Yu,Jun Gong 한국통합생물학회 2022 Animal cells and systems Vol.26 No.4

Pancreatic stellate cells (PSCs) are the primary cell components of pancreatic cancer (PC) and are involved in tumor growth, metastasis and resistance. However, the role and the mechanism of PSCs in gemcitabine (GEM) resistance to PC still need more investigation. We found that CXCL12 mRNA and secreted CXCL12 protein were higher in PSCs after GEM treatment. The conditioned medium (CM) from GEM-treated PSCs reduced the GEM sensitivity of PC cells. Blocking of CXCL12 in CM by anti-CXCL12 antibody partly restored the GEM sensitivity of PC cells. Blocking of CXCL12 decreased glucose consumption, lactate production, ECAR, and glycolysis-related gene expression in PC cells. The PI3K/AKT/mTOR pathway was activated by the binding of CXCL12 and CXCR4. Moreover, CXCR4 mRNA and protein expressions in PC cells were increased after GEM treatment. Our results indicated the cross-talk between PSCs and PC cells during GEM chemotherapy. CXCL12 secreted by PSCs reduces GEM sensitivity of PC cells by binding to CXCR4 and activating PI3K/AKT/mTOR-glycolysis pathway in PC. Our findings would lay the foundation for solving GEM resistance in PC.

Fabrication and Magnetic Properties of A New Fe-based Amorphous Compound Powder Cores

Wang Xiangyue,Guo Feng,Lu Caowei,Lu Zhichao,Li Deren,Zhou Shaoxiong 한국자기학회 2011 Journal of Magnetics Vol.16 No.3

A new Fe-based amorphous compound powder was prepared from Fe-Si-B amorphous powder by crushing amorphous ribbons as the first magnetic component and Fe-Cr-Mo metallic glassy powder by water atomization as the second magnetic component. Subsequently by adding organic and inorganic binders to the compound powder and cold pressing, the new Fe-based amorphous compound powder cores were fabricated. This new Fe-based amorphous compound powder cores combine the superior DC-Bias properties and the excellent core loss. The core loss of 500 ㎾/㎥ at Bm = 0.1T and f = 100 ㎑ was obtained When the mass ratio of FeSiB/FeCrMo equals 3:2, and meanwhile the DC-bias properties of the new Fe-based amorphous compound powder cores just decreased by 10% compared with that of the FeSiB powder cores. In addition, with the increasing of the content of the FeCrMo metallic glassy powder, the core loss tends to decrease.

Mechanical and antibacterial properties of resin co-filled with mesoporous silica and graphene quantum dots

Lu Shuxin,Zhang Hongyu,Chai Maozhou,Yao Xiaohong,Zhang Xiangyu,Yang Yongqiang 한국탄소학회 2023 Carbon Letters Vol.33 No.2

Poor mechanical properties and bacterial infection are the main problems faced by dental restorative resins in clinical use. In this study, graphene quantum dots (GQDs) grafted with imidazole groups and mesoporous silica (MSN) are co-filled in a dental resin to impart excellent antimicrobial activity and mechanical properties to the dental resin. The higher specific surface area of GQDs and MSN results in an increased contact area with the resin matrix, which enhances the strength of the dental composite resin. The introduction of GQDs significantly improves the antimicrobial activity of the resin. The inhibition efficiency of the composite resin against Streptococcus mutans reached 99.9% with the addition of GQDs at only 0.2 wt.%. When MSN and GQDs are co-filled, MSN interferes with the release of GQDs, thus reducing the antimicrobial activity of the dental resin but improving the cyto-compatibility. By reasonably adjusting the amount of GQDs and MSN, the dental composite resin can exhibit excellent antimicrobial properties, mechanical properties and cyto-compatibility at the same time.

Geochemistry of the Early Cretaceous saline lacustrine shales on the Lingshan Island, East China: implications for provenance, tectonic setting, and paleoweathering

Xiangyu Zhang,Lu Liu,Qiang Sun,Yanming Xu,Shoujun Li,Xiaoli Wang,Xuxue Wang,Ying Sun,Wenxia Wang 한국지질과학협의회 2023 Geosciences Journal Vol.27 No.4

Early Cretaceous saline lacustrine black shales in the Fajiaying Formation were deposited under hothouse conditions and have a complex structure and history of sedimentary evolution. In this study, integrated petrographic and geochemical investigations were utilized to determine the provenance, tectonic setting, and paleoweathering conditions of these shales, therefore revealing their depositional history. Shale in the area under investigation has not been subjected to any post-depositional alteration, mechanical sorting, or recycling, hence its geochemistry has not been affected. The chondrite normalized rare earth elements (REE) pattern of shales displayed typical characteristics, including an enrichment in light REE (LREE), a flat pattern for heavy REE (HREE), and a negative europium (Eu) anomaly. Specific trace element ratios suggested that the sediments were primarily derived from felsic source rocks. Furthermore, there was no discernible shift in the sediment source between the Qiancengya and the Laohuzui sections. The discrimination diagrams of major and trace elements used to understand the tectonic history showed that the majority of the source rocks originated from the active continental margin (ACM) and continental island-arc (CIArc). The bivariate plots and low average values of CIW (chemical index of weathering) and CIA (chemical index of alteration) for the examined shale suggested that chemical weathering in the source terrain under arid conditions was extremely weak. Importantly, with the change of climate from dry-hot to warmhumid, an increase in CIA and CIW was observed which indicated a gradual increase in chemical weathering.

Numerical Simulation of Flat Plate Boundary Layer Transition with Synthetic Inlet Turbulence

Lianshan Lu,Xiangyu Wang,Dong Li 한국항공우주학회 2019 International Journal of Aeronautical and Space Sc Vol.20 No.1

A large-eddy simulation (LES) of a flat plate boundary layer undergoing transition to turbulence, i.e., ERCOFTAC’s test case T3B, is performed with synthetic inlet turbulent fluctuations. Generated by Billson and Davidson’s method, the isotropic and homogeneous synthetic turbulence is imposed on a uniform flow directly at the inlet of the computational domain without a precursor adaptation region. The issue of the maximum-contained number (MCN) is specified, which aims at the determination of mesh distribution to maintain and strengthen the correlation between neighboring cells. The numerical results are realistic under the original synthetic turbulence if the MCN is suitably set. For further improvement of the prediction, a correction based on the Poisson equation is adopted to make the synthetic turbulence divergence-free, which is the basic requirement of incompressible flow. It is shown that with the divergence correction, the simulation results are better, and in particular, the decay of free stream turbulence near the upper boundary is more reasonable.

Spermine and oxacillin stress response on the cell wall synthesis and the global gene expression analysis in Methicillin-resistance Staphylococcus aureus

Shrikant Pawar,Xiangyu Yao,Chung‑Dar Lu 한국유전학회 2019 Genes & Genomics Vol.41 No.1

Methicillin-resistant Staphylococcus aureus (MRSA) is a rapidly emerging bacteria causing infection, which has developed resistance to most of the beta-lactam antibiotics because of newly acquired low-affinity penicillin-binding protein (PBP2a), which can continue to build the cell wall when beta-lactams block other PBPs. Exogenous spermine exerts a dose-dependent inhibition effect on the growth of Escherichia coli, Salmonella enterica serovar, and S. aureus. Selection of an MRSA Mu50 derivative which harbors mutation on PBP2 gene (named as MuM) showing spermine resistance and which confers a complete abolishment of spermine-beta-lactam synergy was identified. To further investigate the gene expression changes, a transcriptome profiling of MuM against Mu50 (wild-type) without any treatment, MuM and Mu50 in response to high dose spermine and Mu50 in response to spermine-beta-lactam synergy at 15, 30 and 60 min time points was performed. Functional annotation was further performed to delineate the metabolic pathways associated with the significant genes. A significant down-regulation in the iron regulatory system, potassium channel uptake and polyamine transport system with an up-regulation in general stress response sigB dependent operon in MuM strain at 15, 30 and 60 min time points with spermine treatment compared to Mu50 strain was observed. Analysis of spermine-dependent synergy with beta-lactams on cell wall synthesis revealed that it significantly reduces the degree of cross-linkage on cell wall with no change in trypsin digestion pattern of purified PBPs and without affecting PBPs expression or PBPs acylation by Bocillin. A strong relation between PBP2 protein and general stress sigB response, iron, potassium and polyamine transport systems was observed. SigB regulon should be activated on stress, which was not seen in some of our previous studies where it was down-regulated in wild-type Mu50 strain with spermine stress. Here, an intriguing finding is made where there seems to be a correction of this abnormal response of no SigB induction to a significant induction by PBP2 mutation. In MuM strain, a significant downregulation of KdpABC operon genes at 15, 30 and 60 min time points on spermine stress is seen, which seems to be absent without spermine treatment. Since KCL has been found to protect the cell against spermine stress in wild-type strain by induction of KdpABC operon, it fails to do so in MuM strain underlying the importance of PBP2 protein in spermine stress. Analysis of spermine-dependent synergy with beta-lactams on cell wall synthesis revealed that it significantly reduces the degree of cross-linkage on cell wall with no change in trypsin digestion patterns of purified PBPs and without affecting PBPs expression or PBPs acylation by Bocillin. Furthermore, spermine does not help in enhancing the binding of beta-lactams to PBPs and binding of spermine to PBPs does not cause conformational changes to PBPs, as tested with trypsin digestion patterns. Future studies on the molecular mechanism of spermine interactions with these systems hold great potential for the development of new therapeutics for MRSA infections.

Study on the Net Economic Impact of Mega Sport Events: Perspective of Visitors’ Expenditure (Case Study of the 2010 Guangzhou Asian Games)

Qiuju Luo,Xiangyu Lu 한국관광학회 2014 International Journal of Tourism Sciences Vol.14 No.2

This study assesses the economic impact of the Guangzhou Asian Games from the perspective of that expenditure. It examines how much economic impact sporadic sports mega-events have, and the extent to which their results can be measured by economic data. Expenditure data were collected through questionnaires, and the input-output (I-O) model was used to evaluate the Games’ direct and indirect economic impact. We focus on classifying and quantifying Asian Games visitors, which remove part of the squeezing effect and thus accurately define the net economic impact. Among the several categories of participants investigated, the data show that “event visitors” were the primary source of economic impact from visitors’ expenditure. Although only 32.56% of all visitors were event visitors, their economic contribution made up 61.39%of the total expenditure. Overall, the 722,074 Asian Games visitors produced an economic return of 2,709,247,693 yuan. The average expenditure was 1,688 yuan and the multiplier of output was 2.22. Compared to the Chinese government’s large capital investment in preparation for the Asian Games, the economic impact of visitors’ expenditure was not outstanding. When we include the factor of economic impact in evaluating the effects of sporadic mega-events, it becomes clear that the main benefits lie in non-monetary returns such as the reconstruction of urban spatial structures, the effect on the city’s image, changes in local politics and culture, or improvements to the environment.

Design of stepwise foam claddings subjected to air-blast based on Voronoi model

Minzu Liang,Fangyun Lu,Guodong Zhang,Xiangyu Li 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.23 No.1

Design of stepwise foam claddings subjected to air-blast is performed based on random Voronoialgorithm. FE models are constructed using the random Voronoialgorithm, and numerical analysis is carried out to simulate deformation mode and energy absorption of the cladding by the ABAQUS/Explicit software. The FE model is validated by test result, and good agreement is achieved. The deformation patterns are presented to give an insight into the influences of distribution on deformation mechanisms. The energy absorbed by the stepwise foam cladding is examined, and the parameter effects, including layer number, gradient, and blast loading, are discussed. Results indicate that the energy absorption capacity increases with the number of layer, gradient degree, and blast pressure increasing.

Phenylboronic acid-functionalized gelatin–oleic acid nanoparticles for high loading and efficient transdermal delivery of Celastrol towards the treatment of psoriasis

Jiangtao Su,Na Lin,Xiangyu You,Heshuang Dai,Meng Rao,Lu Ye,Fan Ye,Le Cai,Yuxin Chen,Gao Zhou,Xiaoxia Guo 한국고분자학회 2023 Macromolecular Research Vol.31 No.11

Systemic toxicity, poor aqueous solubility, and poorly cell permeable ability hindered the clinical application of Celastrol. In this study, we aimed to design and synthesize an amphiphilic conjugate to encapsulate Celastrol into micelles to improve its water solubility, cellular membrane penetration, improving the clinic translation potential of Celastrol for the treatment of psoriasis. For this purpose, we first synthesized gelatin and oleic acid conjugate (GOC-1), and then covalently bonded 4-(3-boronophenylamino)-4-oxobutanoic acid (BPOA) with GOC-1 to form a stable GOC-2 conjugate which can self-assemble into micelles in aqueous solution. Celastrol (Cel) was physically encapsulated into the core of GOCs micelles. The dynamic stability, particle size, drug release, zeta potential, drug-loading efficiency, and surface morphology of Cel/loaded GOCs nano-micelles were determined. In addition, cell viability, cellular uptake of Cel/loaded GOC-2, and skin permeation and in vivo anti-psoriasis effect of Cel-loaded GOC-2 were investigated. Our results have shown that Cel/loaded GOC-1 and Cel/loaded GOC-2 have spherical shapes with diameters of around 200–300 nm. Compared to GOC-1, GOC-2 micelles showed higher drug-loading efficiency and excellent permeation ability in vitro. Moreover, Cel/GOC-2 micelles reduced erythema and white scales on the dorsal skin of psoriatic mice. In conclusion, BPOA attached GOC nanoparticles as a Celastrol carrier not only increase its water solubility but also improve drug-loading efficiency and cell permeation ability, exhibiting superior anti-psoriatic effect than the commercially available tacrolimus. Our work is expected to provide a facile approach to prepare nanocarrier for Celastrol to improve the clinic translation potential of Celastrol.