Urchin-Like Ni Microspherical Structure with Enhanced Magnetic Loss for Thin Microwave Absorber at Gigahertz

Yuping Sun,Zhengwu Pan,Hongming Long,Siu Wing Or,S. L. Ho,Chao Feng,Xianguo Liu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.3

We describe in this report a wet chemical reduction synthetic strategy for synthesizing urchin-like Ni microspherical structures, in which the nanowires self-assembled by Ni nanoparticles with the size of 5–20 nm are assembled in a radial form from the center to the surface of the spherical oriented arrays. Urchin-like Ni microspherical structures exhibit the strong magnetic natural resonance peak at 7.0 GHz and superior magnetic loss at 2–18 GHz, originated from relatively high anisotropy energy of urchin-like shape. Electromagnetic absorption measurements show that the urchin-like Ni microspherical structures possess outstanding microwave absorption performance at 2–18 GHz. An optimal reflection loss of –21.98 dB can be observed at 17.4 GHz with a matching thickness of 1.4 mm and the effective absorption (below –10 dB, 90% absorption) bandwidth is 5 GHz (12–17 GHz) with a thickness of 1.7 mm. The excellent microwave absorption performance may be attributed to the good impedance, large attenuation constant and novel magnetic loss ability.

Magnetic Behaviour of Composites Containing Polyacrylate Coated CoFe₂O₄

Hui Liu,Feng Xu,Liangchao Li,Yuping Wang,Haizhen Qiu 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Mechanistic Insight into Phenolic Compounds Toxicity and State-of-the-art Strategies for Enhancing the Tolerance of Escherichia coli to Phenolic Compounds

Lina Liu,Xiaolong Ma,Muhammad Bilal,Linlin Wei,Shijie Tang,Hong-zhen Luo,Yuping Zhao,Xuguo Duan 한국생물공학회 2022 Biotechnology and Bioprocess Engineering Vol.27 No.4

Efficient use of lignocellulosic biomass is a prerequisite for sustainable biofuel production while simultaneously contributing to environmental protection. However, phenolic compounds produced during the chemical treatment of lignocellulose inhibit the growth and metabolism of microorganisms, such as Escherichia coli, which is one of the ideal strains for producing target products by microbial fermentation. To provide new ideas for studying microbial tolerance to environmental stress and providing technical support for constructing the engineering strains with high yields of phenolic compounds, this review elucidates the inhibition mechanism of phenols to E. coli. Secondly, a comprehensive and systematic review of current approaches for improving the phenolic-tolerance of E. coli is provided, including strain domestication, random mutagenesis, regulating the expression of outer membrane proteins, changing the composition of membrane fatty acids, accelerating the efflux of phenolic compounds, engineered bacterial biofloc formation, and transcriptome analysis. Finally, this review ends with some questions that still exist today, and prospective strategies are outlined for further improving the phenols-tolerance of E. coli. This review provided a theoretical basis for research into microbial tolerance to environmental stress and the development of engineered strains with high yield of phenolic compounds.

Artificial Ground Freezing In Tunnelling Through Aquifer Soil Layers: a Case Study in Nanjing Metro Line 2

Jun Hu,Yong Liu,Yuping Li,Kai Yao 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.10

In this paper, the construction of a section of Nanjing Metro Line 2, a shallow underground tunnel constructed with an underground mining method, was analysed. Due to the existence of two aquifer soil layers near the tunnel, water and sand inrush occurred during the tunnelling process. This disrupted tunnelling project was covered until the artificial ground freezing technique was used to achieve a waterless environment. After the 40-day active freezing period, the ground temperature conditions satisfied the design requirements, thereby ensuring the construction schedule. The ground freezing technique and other supplementary measurements were introduced in this study, which could be useful for other similar projects.

Indium doping effect on the magnetic properties of Y-type hexaferrite Ba0.5Sr1.5Zn2(Fe1-xInx)12O22

Min Zhang,Lihua Yin,Qiangchun Liu,Zhenfa Zi,Jianming Dai,Yuping Sun 한국물리학회 2018 Current Applied Physics Vol.18 No.9

The effect of indium doping on structural and magnetic properties of Y-type hexaferrite Ba0.5Sr1.5Zn2(Fe1- xInx)12O22 (x=0, 0.02, 0.04, 0.06, 0.08 and 0.1) prepared by the solid state reaction method was investigated. The Rietveld refinement method was used to analyze the X-ray diffraction patterns. The magnetic transition temperatures associated with the proper-screw spin phase to the collinear ferrimagnetic spin phase transition can be efficiently modulated by varying indium content. The magnetic transition temperature increases to a maximum with indium content x=0.04 and then decreases with x, suggesting the possibility that electrically controlled magnetization reversal can be can be effectively tailored by varying indium content. The saturation magnetization at room temperature was decreased as increasing indium content, which can be explained as the metal ions occupation. It is worthy to note that the coercivity of In-doped samples was decreased drastically compared that of undoped sample, which is probably resulted from the reduction in anisotropy field with substitution of In3+ for Fe3+. The In-doped hexaferrite Ba0.5Sr1.5Zn2(Fe1-xInx)12O22 may be potential candidates for application in magnetoelectric devices.

Effervescent cannabidiol solid dispersion-doped dissolving microneedles for boosted melanoma therapy via the “TRPV1-NFATc1-ATF3” pathway and tumor microenvironment engineering

Jiachen Shi,Qiuling Ma,Wenting Su,Congyan Liu,Huangqin Zhang,Yuping Liu,Xiaoqi Li,Xi Jiang,Chang Ge,Fei Kong,Yan Chen,Ding Qu 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Conventional dissolving microneedles (DMNs) face significant challenges in anti-melanoma therapy due to the lack of active thrust to achieve efficient transdermal drug delivery and intra-tumoral penetration. Methods In this study, the effervescent cannabidiol solid dispersion-doped dissolving microneedles (Ef/CBD-SD@ DMNs) composed of the combined effervescent components (CaCO3 & NaHCO3) and CBD-based solid dispersion (CBD-SD) were facilely fabricated by the “one-step micro-molding” method for boosted transdermal and tumoral delivery of cannabidiol (CBD). Results Upon pressing into the skin, Ef/CBD-SD@DMNs rapidly produce CO2 bubbles through proton elimination, significantly enhancing the skin permeation and tumoral penetration of CBD. Once reaching the tumors, Ef/CBD-SD@ DMNs can activate transient receptor potential vanilloid 1 (TRPV1) to increase Ca2+ influx and inhibit the downstream NFATc1-ATF3 signal to induce cell apoptosis. Additionally, Ef/CBD-SD@DMNs raise intra-tumoral pH environment to trigger the engineering of the tumor microenvironment (TME), including the M1 polarization of tumor-associated macrophages (TAMs) and increase of T cells infiltration. The introduction of Ca2+ can not only amplify the effervescent effect but also provide sufficient Ca2+ with CBD to potentiate the anti-melanoma efficacy. Such a “one stone, two birds” strategy combines the advantages of effervescent effects on transdermal delivery and TME regulation, creating favorable therapeutic conditions for CBD to obtain stronger inhibition of melanoma growth in vitro and in vivo. Conclusions This study holds promising potential in the transdermal delivery of CBD for melanoma therapy and offers a facile tool for transdermal therapies of skin tumors.

Arginine Supplementation Recovered the IFN-γ-Mediated Decrease in Milk Protein and Fat Synthesis by Inhibiting the GCN2/eIF2α Pathway, Which Induces Autophagy in Primary Bovine Mammary Epithelial Cells

Xia, Xiaojing,Che, Yanyi,Gao, Yuanyuan,Zhao, Shuang,Ao, Changjin,Yang, Hongjian,Liu, Juxiong,Liu, Guowen,Han, Wenyu,Wang, Yuping,Lei, Liancheng Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.5

During the lactation cycle of the bovine mammary gland, autophagy is induced in bovine mammary epithelial cells (BMECs) as a cellular homeostasis and survival mechanism. Interferon gamma ($IFN-{\gamma}$) is an important antiproliferative and apoptogenic factor that has been shown to induce autophagy in multiple cell lines in vitro. However, it remains unclear whether $IFN-{\gamma}$ can induce autophagy and whether autophagy affects milk synthesis in BMECs. To understand whether $IFN-{\gamma}$ affects milk synthesis, we isolated and purified primary BMECs and investigated the effect of $IFN-{\gamma}$ on milk synthesis in primary BMECs in vitro. The results showed that $IFN-{\gamma}$ significantly inhibits milk synthesis and that autophagy was clearly induced in primary BMECs in vitro within 24 h. Interestingly, autophagy was observed following $IFN-{\gamma}$ treatment, and the inhibition of autophagy can improve milk protein and milk fat synthesis. Conversely, upregulation of autophagy decreased milk synthesis. Furthermore, mechanistic analysis confirmed that $IFN-{\gamma}$ mediated autophagy by depleting arginine and inhibiting the general control nonderepressible-2 kinase (GCN2)/eukaryotic initiation factor $2{\alpha}$ ($eIF2{\alpha}$) signaling pathway in BMECs. Then, it was found that arginine supplementation could attenuate $IFN-{\gamma}$-induced autophagy and recover milk synthesis to some extent. These findings may not only provide a novel measure for preventing the $IFN-{\gamma}$-induced decrease in milk quality but also a useful therapeutic approach for $IFN-{\gamma}$-associated breast diseases in other animals and humans.

Mesoporous CexZr1−xO2 solid solutions supported CuO nanocatalysts for toluene total oxidation

Qing-Fang Deng,Tie-Zhen Ren,Bao Agula,Yuping Liu,Zhong-Yong Yuan 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.5

Mesoporous CexZr1 xO2 solid solutions were prepared by the surfactant-assisted method and used as support of CuO nanocatalysts for catalytic total oxidation of toluene. The prepared CuO/CexZr1 xO2 catalysts have a wormhole-like mesoporous structure with high surface area and uniform pore size distribution, and the CuO nanoparticles were highly dispersed on the surface of CexZr1 xO2. The doping of ZrO2 in CeO2 promotes the dispersion of active copper species and enhances the reducibility of copper species. The effect of Ce/Zr ratio, calcination temperature and CuO loading amount on the catalytic performance of CuO/CexZr1 xO2 was investigated in detail. The 400 ℃-calcined 8%CuO/Ce0.8Zr0.2O2 catalyst exhibits the highest activity with the complete toluene conversion temperature of 275 ℃ at the condition of GHSH = 33,000 h-1 and the toluene concentration of 4400 ppm. The interfacial interaction between CuO and the CexZr1 xO2 support, highly dispersed CuO nanoparticles and the nature of the support contribute to the high catalytic activity of mesoporous CuO/CexZr1 xO2 nanocatalysts.

Research on vibration control of a transmission tower-line system using SMA-BTMD subjected to wind load

Li Tian,Jingyu Luo,Mengyao Zhou,Wenzhe Bi,Yuping Liu 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.5

As a vital component of power grids, long-span transmission tower-line systems are vulnerable to wind load excitation due to their high flexibility and low structural damping. Therefore, it is essential to reduce wind-induced responses of tower-line coupling systems to ensure their safe and reliable operation. To this end, a shape memory alloy-bidirectional tuned mass damper (SMA-BTMD) is proposed in this study to reduce wind-induced vibrations of long-span transmission tower-line systems. A 1220 m Songhua River long-span transmission system is selected as the primary structure and modeled using ANSYS software. The vibration suppression performance of an optimized SMA-BTMD attached to the transmission tower is evaluated and compared with the effects of a conventional bidirectional tuned mass damper. Furthermore, the impacts of frequency ratios and SMA composition on the vibration reduction performance of the SMA-BTMD are evaluated. The results show that the SMA-BTMD provides superior vibration control of the long-span transmission tower-line system. In addition, changes in frequency ratios and SMA composition have a substantial impact on the vibration suppression effects of the SMABTMD. This research can provide a reference for the practical engineering application of the SMA-BTMD developed in this study.

LAB Fermentation Improves Production of Bioactive Compounds and Antioxidant Activity of Withania somnifera Extract and Its Metabolic Signatures as Revealed by LC-MS/MS

( Jinhui Yu ),( Yun Geng ),( Han Xia ),( Deyuan Ma ),( Chao Liu ),( Rina Wu ),( Junrui Wu ),( Shengbo You ),( Yuping Bi ) 한국미생물생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.4

In this study we investigated the effect of lactic acid bacteria (LAB) fermentation on the ingredients and anti-oxidant activity of Withania somnifera extract. Four strains of LAB could proliferate normally in medium containing W. somnifera extract after the pH reached 3.1~3.5. LAB fermentation increased the content of alcohols and ketones, endowing the extract with the characteristic aroma of fermentation. Compared to the control, the DPPH and ABTS free radical scavenging rates in the fermented samples were significantly improved, ranging from 48.5% to 59.6% and 1.2% to 6.4%. The content of total phenols was significantly increased by 36.1% during the fermentation of mixed bacteria. Moreover, the original composition spectrum of the extract was significantly changed while the differentially accumulated metabolites (DAMs) were closely related to bile secretion, tryptophan metabolism and purine metabolism. Therefore, LAB fermentation can be used as a promising way to improve the flavor and bioactivity of the extracts of W. somnifera, making the ferments more attractive for use as functional food.