Realizing highly efficient multicolor tunable emissions from Tb³⁺ and Eu³⁺ co-doped CaGd₂(WO₄)₄ phosphors via energy transfer by single ultraviolet excitation for lighting and display applications

Huang, Xiaoyong,Li, Bin,Du, Peng,Guo, Heng,Cao, Renping,Yu, Jae Su,Wang, Kai,Sun, Xiao Wei Elsevier 2018 Dyes and pigments Vol.151 No.-

<P><B>Abstract</B></P> <P>In this paper, we reported on multicolor emission tuning in Tb<SUP>3+</SUP> and Eu<SUP>3+</SUP> co-doped CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB> phosphors prepared by a traditional high-temperature solid-state reaction. Upon 380 nm ultraviolet excitation, the emission color of CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> phosphors can be readily tuned from green to yellow, orange and finally to pure red through varying the concentration ratio of Eu<SUP>3+</SUP> and Tb<SUP>3+</SUP> ions. The energy transfer mechanism from Tb<SUP>3+</SUP> to Eu<SUP>3+</SUP> was systematically investigated by photoluminescence spectra, luminescence decay times, and time-resolved spectra. The internal quantum efficiencies of these phosphors were measured, and their thermal stability was also studied. A prototype white light-emitting diode (LED) device was fabricated by using an ultraviolet chip combined with a blend of blue-emitting BaMgAl<SUB>10</SUB>O<SUB>l7</SUB>:Eu<SUP>2+</SUP> phosphors, green-emitting BaSrSiO<SUB>4</SUB>:Eu<SUP>2+</SUP> phosphors, and red-emitting CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:50%Tb<SUP>3+</SUP>,50%Eu<SUP>3+</SUP> phosphors. All the results indicate that the CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> has great potential application in lighting and displays.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> showed efficient energy-transfer from Tb<SUP>3+</SUP> to Eu<SUP>3+</SUP>. </LI> <LI> CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> exhibited tunable color emission under 380 nm excitation. </LI> <LI> The energy-transfer mechanism was studied in detail. </LI> <LI> Quantum efficiency and thermal stability were investigated. </LI> <LI> The proof-of-concept LED lamps were fabricated by employing phosphors and UV LEDs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Prevalence of new psychoactive substances in Northeast Asia from 2007 to 2015

Lee, Junhui,Yang, Songhee,Kang, Yujin,Han, Eunyoung,Feng, Ling-Yi,Li, Jih-Heng,Chung, Heesun Elsevier Sequoia 2017 Forensic science international Vol.272 No.-

<P><B>Abstract</B></P> <P>The proliferation of new psychoactive substances (NPS) has been a global trend in drug abuse and its regulation has been a worldwide concern. There is no doubt that it is necessary to share information related to these emerging substances between countries and continents for the effective regulation of NPS. With efforts for the efficient regulation of NPS, many studies and information have been published for the prevalence of NPS in the United States and other countries in Europe and Oceania. However, there is lack of information available for the prevalence of NPS in Asian and African countries. Therefore, this research was focused on the investigation of legal status of certain NPS in Northeast Asian countries, including China, Japan, South Korea and Taiwan, in order to provide information on the prevalence and trend of emerging NPS in these countries. The results showed that a total of 940 NPS was reported in 4 Northeast Asian countries from 2007 to 2015. Among 940 NPS, 882 NPS are legally restricted in at least one country (94%) and 96 substances were not currently under control (6%) in these countries. The number of controlled NPS that are currently controlled in all 4 countries was only 25 (or 28%) out of 882 NPS. Each substance was categorized in 9 groups according to the classification proposed by the United Nations Office on Drugs and Crime (UNODC). In Northeast Asia, the most commonly controlled NPS were synthetic cannabinoids, synthetic cathinones, and phenethylamines. It was found that Japan is the most proactive country in terms of the NPS regulation with 41% of the total number of controlled NPS in Northeast Asia, followed by South Korea (21%), China (28%), Taiwan (10%). Comparing the number of NPS newly regulated in each country every year, NPS has been broadly scheduled in 2011 and the number of scheduled NPS has dramatically increased from 2013 to 2015. It was shown that Northeast Asia is also in danger of these emerging NPS and the effective regulation across countries is important for the prevention of NPS. Also, this study will bring attention to local law enforcement in the construction of local drug crime prevention network sharing information for these controlled substances.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The trend and legal status of NPS in China, Japan, Korea and Taiwan was studied. </LI> <LI> Among total of 940 NPS reported, only 25 are currently controlled in 4 countries. </LI> <LI> Japan is the most proactive country regarding the NPS regulation followed by Korea. </LI> <LI> The information on emerging NPS in four countries was conducted for the first time. </LI> </UL> </P>

Analysis and Prevention of the Realistic Threats of Bioterrorism

Li Heng(Heng Li),Zhou Shenglong(Shenglong Zhou),Hu Shuangqing(Shuangqing Hu) 아시아사회과학학회 2022 International Science Research Vol.2 No.3

At present, the abuse of biotechnology achievements is gradually escalating, and it has become the most urgent emerging biological threat source. The biosafety risks in laboratories are constantly escalating, and the procurement, transportation, transfer and research of virus samples often violate operational norms, posing a serious threat to public safety. From the perspective of the environment faced by China, the situation of anti-bioterrorism threat is not optimistic. There are still obvious shortcomings in internal risk control such as pathogenic microorganism laboratory safety. External risks such as biological virus transmission, biological weapon development, bioterrorism attack and biotechnology abuse continue to intensify, and new risk factors such as loss of biological genetic resources are making waves. All countries in the world should join hands to deal with the threat of bioterrorism.

Recent advances in microfluidic technology for manipulation and analysis of biological cells (2007–2017)

Alam, Md Kowsar,Koomson, Emmanuel,Zou, Heng,Yi, Changqing,Li, Cheuk-Wing,Xu, Tao,Yang, Mengsu Elsevier Pub. Co 2018 Analytica Chimica Acta Vol. No.

<P><B>Abstract</B></P> <P>The pivotal role of microfluidic technology in life science and biomedical research is now widely recognized. Indeed, microfluidics as a research tool is unparalleled in terms of its biocompatibility, robustness, efficient reagent consumption, and controlled fluidic, surface, and structure environments. The controlled environments are essential in assessing the complex behavior of cells in response to microenvironmental cues. The strengths of microfluidics also reside in its amenability to integration with other analytical platforms and its capacity for miniaturization, parallelization and automation of biochemical assays. Following previous review on the applications of microfluidic devices for cell-based assays in 2006, we have monitored the progress in the field and summarized the advances in microfluidic technology from 2007 to 2017, with a focus on microfluidics development for applications in cell manipulation, cell capture and detection, and cell treatment and analysis. Moreover, we highlighted novel commercial microfluidic products for biomedical and clinical purposes that were introduced in the review period. Thus, this review provides a comprehensive source for recent developments in microfluidics and presents a snapshot of its remarkable contribution towards basic biomedical research and clinical science. We recognize that although enormous amounts of evidence have reinforced the promise of microfluidic technology across diverse applications, much remains to be done to realize its full potential in mainstream biomedical science and clinical practice.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Advances in microfluidic technology for cell analysis in the last decade were reviewed. </LI> <LI> Microfluidic platforms exhibited superior spatiotemporal resolution for cell manipulation and monitoring of cellular responses.. </LI> <LI> Commercialization of microfluidic technology has gained traction in biomedical research and diagnostic applications. . </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

SPON2 Promotes M1-like Macrophage Recruitment and Inhibits Hepatocellular Carcinoma Metastasis by Distinct Integrin–Rho GTPase–Hippo Pathways

Zhang, Yan-Li,Li, Qing,Yang, Xiao-Mei,Fang, Fang,Li, Jun,Wang, Ya-Hui,Yang, Qin,Zhu, Lei,Nie, Hui-Zhen,Zhang, Xue-Li,Feng, Ming-Xuan,Jiang, Shu-Heng,Tian, Guang-Ang,Hu, Li-Peng,Lee, Ho-Young,Lee, Su-J American Association for Cancer Research 2018 Cancer research Vol.78 No.9

<P>Matricellular protein SPON2 acts as an HCC suppressor and utilizes distinct signaling events to perform dual functions in HCC microenvironment.</P><P>Tumor-associated macrophages (TAM) represent key regulators of the complex interplay between cancer and the immune microenvironment. Matricellular protein SPON2 is essential for recruiting lymphocytes and initiating immune responses. Recent studies have shown that SPON2 has complicated roles in cell migration and tumor progression. Here we report that, in the tumor microenvironment of hepatocellular carcinoma (HCC), SPON2 not only promotes infiltration of M1-like macrophages but also inhibits tumor metastasis. SPON2-α4β1 integrin signaling activated RhoA and Rac1, increased F-actin reorganization, and promoted M1-like macrophage recruitment. F-Actin accumulation also activated the Hippo pathway by suppressing LATS1 phosphorylation, promoting YAP nuclear translocation, and initiating downstream gene expression. However, SPON2-α5β1 integrin signaling inactivated RhoA and prevented F-actin assembly, thereby inhibiting HCC cell migration; the Hippo pathway was not noticeably involved in SPON2-mediated HCC cell migration. In HCC patients, SPON2 levels correlated positively with prognosis. Overall, our findings provide evidence that SPON2 is a critical factor in mediating the immune response against tumor cell growth and migration in HCC.</P><P><B>Significance:</B> Matricellular protein SPON2 acts as an HCC suppressor and utilizes distinct signaling events to perform dual functions in HCC microenvironment.</P><P><B>Graphical Abstract:</B> http://cancerres.aacrjournals.org/content/canres/78/9/2305/F1.large.jpg. <I>Cancer Res; 78(9); 2305–17. ©2018 AACR</I>.</P><P><B>Graphical Abstract</B></P><P> [Figure]</P>

A Study On Critical Thinning In Thin-walled Tube Bending Of Al-Alloy 5052O Via Coupled Ductile Fracture Criteria

Heng Li,He Yang,Mei Zhan 한국소성가공학회 2010 기타자료 Vol.2010 No.6

Thin-walled tube bending(TWTB) method of Al-alloy tube has attracted wide applications in aerospace, aviation and automobile,etc. While, under in-plane double tensile stress states at the extrados of bending tube, the overthinning induced ductile fracture is one dominant defect in Al-alloy tube bending. The main objective of this study is to predict the critical wall-thinning of Al-alloy tube bending by coupling two ductile fracture criteria(DFCs) into FE simulation. The DFCs include Continuum Damage Mechanics(CDM)-based model and GTN porous model. Through the uniaxial tensile test of the curved specimen, the basic material properties of the Al-alloy 5052O tube is obtained; via the inverse problem solution, the damage parameters of both the two fracture criteria are interatively determined. Thus the application study of the above DFCs in the TWTB is performed, and the more reasonable one is selected to obtain the critical thinning of Al-alloy tube in bending. The virtual damage initiation and evolution (when and where the ductile fracture occurs) in TWTB are investigated, and the fracture mechanisms of the voided Al-alloy tube in tube bending are consequently discussed.

A New Ferulic Acid Ester and Other Constituents from Dracocephalum peregrinum

Li-Min Dai,Chun-Chao Zhao,Hui-zi Jin,Yun-Heng Shen,Hui-Liang Li,Cai-Yun Peng,Jian Tang,Wei-Dong Zhang 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.10

A new ferulic acid ester, 1'-methyl-2'-hydroxyethyl ferulate (1), together with methylcaffeate (2), 4- hydroxy cinnamic acid (3), ferulic acid (4), caffeic acid (5), diosmetin (6), luteolin (7), 5,3',4'-trihydroxy- 3,7-dimethoxyflavone (8), eriodictyol (9), kaempferol (10), quercetin (11), acacetin-7-Oglcopyranoside (12), 4-(β-glucopyranosyloxy) benzoic acid (13), luteolin-7-O-(6''-feruloyl) glucopyranoside (14), luteolin-7-O-glucopyranoside (15), kaempferide-3-O-rhamnopyranoside (16), quercitrin (17), kaempferol-3-O-glucopyranoside (18), prunasin (19), quercetin-7-O-glucopyranoside (20), quercetin-3-O-glucopyranoside (21), plantaginin (22), linarin (23), luteolin-7-O-rutinoside (24), and chlorogenic acid (25) were isolated from the aerial parts of Dacocephalum peregrinum. The structure of 1 was elucidated on the basis of spectroscopic and HR-ESI-MS analyses. In addition, compound 1 exhibited mild inhibitory effect on NO production in LPS-stimulated RAW264.7 cells.

Springback Nonlinearity of High-strength Titanium Alloy Tube upon Mandrel Bending

Heng Li,He Yang,Fei-Fei Song,Guang-Jun Li 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

Taking the stress-relieved Ti-3Al-2.5V tube as the objective, regarding both angular and radius springback, the nonlinear springback behaviors of the high-strength titanium tube (HSTT) upon the universal bending, viz., mandrel bending (rotary draw bending), are clarified. The experiments are conducted to identify the springback and validate the theoretical models, and the deformation theory of plasticity and the explicit/implicit 3D-FE based models are used to reveal the rules and the physical mechanism of the nonlinearity of elastic recovery. The results show that: 1) At early bending stages, the angular springback increases nonlinearly with larger bending angles, then it increases linearly when the bending angle exceeds a critical one; While the radius growth decreases exponentially with the increasing of the bending angles at early stages, then it remains unchanged when the bending angle exceeds another critical value; The springback behaves more nonlinearly under smaller bending radii; Both the critical values for the two springback phenomena become larger with smaller bending radii; The critical angle for radius springback is larger than the one for angular springback. 2) The relationship between the radius springback and angular one is further identified; The radius springback can be estimated by the angular springback of the bending regions of tube; The variation of bending radii has significant effect on angular and radius springback, while it has little influence on the springback angle by the straight regions; The variation of the material properties affects both the springback phenomena much more significantly than the changing of the processing parameters.

Synthesis and Properties of Cellulose-based Superabsorbent Hydrogel by a New Crosslinker

Heng-Xiang Li,Xin Tian,Luming Zhang,Leili Wang,Li’e Jin,Qing Cao 한국섬유공학회 2020 Fibers and polymers Vol.21 No.7

Cellulose-based superabsorbent hydrogel (SAH) has been successfully prepared by the grafting method withcellulose and sodium acrylate as well as aluminum hydroxide as a novel crosslinker. The factors influencing water absorptionsuch as the neutralization degree of acrylic acid (AA), the amount of initiator ammonium persulfate (APS) and crosslinker,and the proportion of cellulose to AA were investigated. The chemical structure and thermal behavior of the SAH wereanalyzed by fourier-transform infrared spectrometry, field-emission scanning electron microscopy, and thermal gravimetry,respectively. Results showed that the water absorbency of the SAH in distilled water and 0.9 wt% NaCl solution reached 922and 118 g/g when the mass ratio of cellulose to AA, APS to AA, Al(OH)3 to AA, and the neutralization degree of AA was39 wt%, 0.67 wt%, 0.89 %, and 76 %, respectively. Under the same condition, the hydrogel synthesized by traditionalcrosslinker N,N-methylenebisacrylamide was only 530 and 84 g/g in distilled water and 0.9 wt% NaCl solution, respectively. The mechanism of polymerization reaction was analyzed. And the cost and feasibility for the mass-producing the hydrogelwere analyzed.

Studies on the Mechanism of AIN Synthesis by Chemical Vapor Deposition

Li, Chun-Zhong,Hu, Li-Ming,Yuan, Wei-Kang,Chen, Min-Heng 한국재료학회 1995 Fabrication and Characterization of Advanced Mater Vol.2 No.4

Ultrafine AIN particles were synthesized by chemical vapor deposition at 973-1273K. Effects of reaction temperature, totlaflow rate AIC$l_3$ concentration on AIN particle morphology, particle size distribution were studied. Also investigated was the mechanism of the reaction between AIC$l_3$ and N$H_3$. The mechanisms for homogeneous formation of AIN particles and growth of AIN film by surface reactions were investigated.