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>

Performance Optimization and Analysis on P2P Mobile Communication Systems Accelerated by MEC Servers

( Xuesong Liang ),( Yongpeng Wu ),( Yujin Huang ),( Derrick Wing Kwan Ng ),( Pei Li ),( Yingbiao Yao ) 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.1

As a promising technique to support tremendous numbers of Internet of Things devices and a variety of applications efficiently, mobile edge computing (MEC) has attracted extensive studies recently. In this paper, we consider a MEC-assisted peer-to-peer (P2P) mobile communication system where MEC servers are deployed at access points to accelerate the communication process between mobile terminals. To capture the tradeoff between the time delay and the energy consumption of the system, a cost function is introduced to facilitate the optimization of the computation and communication resources. The formulated optimization problem is non-convex and is tackled by an iterative block coordinate descent algorithm that decouples the original optimization problem into two subproblems and alternately optimizes the computation and communication resources. Moreover, the MEC-assisted P2P communication system is compared with the conventional P2P communication system, then a condition is provided in closed-form expression when the MEC-assisted P2P communication system performs better. Simulation results show that the advantage of this system is enhanced when the computing capability of the receiver increases whereas it is reduced when the computing capability of the transmitter increases. In addition, the performance of this system is significantly improved when the signal-to-noise ratio of hop-1 exceeds that of hop-2.

Two-dimensional porous polyphthalocyanine (PPc) as an efficient gas-separation membrane for ammonia synthesis

Zhaoran Wang,Huilong Dong,Xiaohui Yu,Yujin Ji,Tingjun Hou,Youyong Li 한국물리학회 2017 Current Applied Physics Vol.17 No.12

Porous monolayer materials have been proven potential for gas separation and purification, because of their natural pathways of controllable sizes and well-ordered distribution. In this work, a novel material, two-dimensional (2D) porous polyphthalocyanine (PPc) is investigated by density functional theory (DFT) simulations for separating NH3 from H2 and N2 during ammonia synthesis process. Based on the calculated diffusion barriers through transition state search, we demonstrate that 2D PPc is able to offer high selectivity (107) of (H2, N2)/NH3 at room temperature. Further molecular dynamics (MD) simulation also indicates that the 2D PPc can effectively separate NH3 from H2 and N2. Thus the 2D PPc is promising for the practical applications of synthetic ammonia process.

Bright visible light emission from graphene

Kim, Young Duck,Kim, Hakseong,Cho, Yujin,Ryoo, Ji Hoon,Park, Cheol-Hwan,Kim, Pilkwang,Kim, Yong Seung,Lee, Sunwoo,Li, Yilei,Park, Seung-Nam,Shim Yoo, Yong,Yoon, Duhee,Dorgan, Vincent E.,Pop, Eric,Hein Nature Publishing Group 2015 Nature nanotechnology Vol.10 No.8

Graphene and related two-dimensional materials are promising candidates for atomically thin, flexible and transparent optoelectronics. In particular, the strong light–matter interaction in graphene has allowed for the development of state-of-the-art photodetectors, optical modulators and plasmonic devices. In addition, electrically biased graphene on SiO<SUB>2</SUB> substrates can be used as a low-efficiency emitter in the mid-infrared range. However, emission in the visible range has remained elusive. Here, we report the observation of bright visible light emission from electrically biased suspended graphene devices. In these devices, heat transport is greatly reduced. Hot electrons (∼2,800 K) therefore become spatially localized at the centre of the graphene layer, resulting in a 1,000-fold enhancement in thermal radiation efficiency. Moreover, strong optical interference between the suspended graphene and substrate can be used to tune the emission spectrum. We also demonstrate the scalability of this technique by realizing arrays of chemical-vapour-deposited graphene light emitters. These results pave the way towards the realization of commercially viable large-scale, atomically thin, flexible and transparent light emitters and displays with low operation voltage and graphene-based on-chip ultrafast optical communications.

Convective heat transfer characteristics of nanofluids under laminar and turbulent flow conditions

Younghwan Kwon,Yonghyeon Cho,Chengguo Li,Seongir Cheong,Yujin Hwang,Jaekeun Lee,Daeseung Hong,Seongyong Moonb 한국물리학회 2009 Current Applied Physics Vol.9 No.2

To investigate the effect of nanofluids on convective heat transfer, an experimental study was performed through a circular straight tube with a constant heat flux condition in the laminar and turbulent flow regime. Stable nanofluids, which were water-based suspensions of alumina and amorphous carbonic nanoparticles, were prepared by two- and one-step methods. The effects of thermal conductivity and supernatant nanoparticles of the nanofluids on convective heat transfer were investigated under different flow regimes. In alumina nanofluids containing 3 vol% of suspended particles, the increment of thermal conductivity and convective heat transfer coefficient was 8% and 20%, respectively. For amorphous carbonic nanofluids, the thermal conductivity was similar to that of water, and the convective heat transfer coefficient increased by only 8% in laminar flow. In a comparison of thermal conductivity and convection, the enhancement of the convective heat transfer was much higher than that of the thermal conductivity of nanofluids. The movements of nanoparticles enhanced the convective heat transfer at the entrance region. To investigate the effect of nanofluids on convective heat transfer, an experimental study was performed through a circular straight tube with a constant heat flux condition in the laminar and turbulent flow regime. Stable nanofluids, which were water-based suspensions of alumina and amorphous carbonic nanoparticles, were prepared by two- and one-step methods. The effects of thermal conductivity and supernatant nanoparticles of the nanofluids on convective heat transfer were investigated under different flow regimes. In alumina nanofluids containing 3 vol% of suspended particles, the increment of thermal conductivity and convective heat transfer coefficient was 8% and 20%, respectively. For amorphous carbonic nanofluids, the thermal conductivity was similar to that of water, and the convective heat transfer coefficient increased by only 8% in laminar flow. In a comparison of thermal conductivity and convection, the enhancement of the convective heat transfer was much higher than that of the thermal conductivity of nanofluids. The movements of nanoparticles enhanced the convective heat transfer at the entrance region.

Inhibition of mouse SP2/0 myeloma cell growth by the B7-H4 protein vaccine

( Nan Mu ),( Nannan Liu ),( Qiang Hao ),( Yujin Xu ),( Jialin Li ),( Weina Li ),( Shouzhen Wu ),( Cun Zhang ),( Haichuan Su ) 생화학분자생물학회 2014 BMB Reports Vol.47 No.7

B7-H4 is a member of B7 family of co-inhibitory molecules and B7-H4 protein is found to be overexpressed in many human cancers and which is usually associated with poor survival. In this study, we developed a therapeutic vaccine made from a fusion protein composed of a tetanus toxoid (TT) T-helper cell epitope and human B7-H4IgV domain (TT-rhB7-H4IgV). We investigated the anti-tumor effect of the TT-rhB7-H4IgV vaccine in BALB/c mice and SP2/0 myeloma growth was significantly suppressed in mice. The TT-rhB7-H4IgV vaccine induced high-titer specific antibodies in mice. Further, the antibodies induced by TT-rhB7-H4IgV vaccine were capable of depleting SP2/0 cells through complement-dependent cytotoxicity (CDC) in vitro. On the other hand, the poor cellular immune response was irrelevant to the therapeutic efficacy. These results indicate that the recombinant TT-rhB7-H4IgV vaccine might be a useful candidate of immunotherapy for the treatment of some tumors associated with abnormal expression of B7-H4. [BMB Reports 2014; 47(7): 399-404]

Analysis of the extrusion pressure of a cylindrical extruder for extruding highly viscous fluids

Zhibin Sun,Baojun Shen,Yu He,Jiecai Long,Xiaobin Zhan,Yujin Li,Xiwen Li 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.10

Extrusion pressure is crucial for the security and performance of a cylindrical extruder during the extrusion process. In this study, a validated CFD model was adopted to evaluate the relationship between the extrusion velocity, fluid viscosity, and the extrusion pressure of a cylindrical extruder while extruding highly viscous fluids. The simulated and experimental results of the extrusion pressure and velocity profiles show good agreement. This study reveals that extrusion pressure evolution can be divided into two stages during the extrusion process. At stage I, the distance between the ram and the bottom of the vessel (liquid height) is greater than the critical height and the extrusion pressure remains almost constant. At stage II, the distance is less than the critical height and the extrusion pressure increases exponentially. The results indicate that an increase in extrusion velocity and fluid viscosity leads to a linear increase in the extrusion pressure at stage I. Furthermore, by introducing a pressure number, Np, and a pressurerelated Reynolds number, Rep, a novel correlation of the extrusion pressure with the extrusion velocity, viscosity of highly viscous fluids and liquid height has been developed.

Snake fang–inspired stamping patch for transdermal delivery of liquid formulations

Bae, Won-Gyu,Ko, Hangil,So, Jin-Young,Yi, Hoon,Lee, Chan-Ho,Lee, Dong-Hun,Ahn, Yujin,Lee, Sang-Hyeon,Lee, Kyunghun,Jun, Joonha,Kim, Hyoung-Ho,Jeon, Noo Li,Jung, Woonggyu,Song, Chang-Seon,Kim, Taesung American Association for the Advancement of Scienc 2019 Science Translational Medicine Vol.11 No.503

<P>A flexible microneedle patch that can transdermally deliver liquid-phase therapeutics would enable direct use of existing, approved drugs and vaccines, which are mostly in liquid form, without the need for additional drug solidification, efficacy verification, and subsequent approval. Specialized dissolving or coated microneedle patches that deliver reformulated, solidified therapeutics have made considerable advances; however, microneedles that can deliver liquid drugs and vaccines still remain elusive because of technical limitations. Here, we present a snake fang–inspired microneedle patch that can administer existing liquid formulations to patients in an ultrafast manner (<15 s). Rear-fanged snakes have an intriguing molar with a groove on the surface, which enables rapid and efficient infusion of venom or saliva into prey. Liquid delivery is based on surface tension and capillary action. The microneedle patch uses multiple open groove architectures that emulate the grooved fangs of rear-fanged snakes: Similar to snake fangs, the microneedles can rapidly and efficiently deliver diverse liquid-phase drugs and vaccines in seconds under capillary action with only gentle thumb pressure, without requiring a complex pumping system. Hydrodynamic simulations show that the snake fang–inspired open groove architectures enable rapid capillary force–driven delivery of liquid formulations with varied surface tensions and viscosities. We demonstrate that administration of ovalbumin and influenza virus with the snake fang–inspired microneedle patch induces robust antibody production and protective immune response in guinea pigs and mice.</P>

Antioxidant Production and Chitin Recovery from Shrimp Head Fermentation with Streptococcus thermophilus

Xiangzhao Mao,Jing Zhang,Feifei Kan,Yuansong Gao,Jing Lan,Xiaowei Zhang,Zengmiao Hu,Yujin Li,Hong Lin 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.4

Fermentation of shrimp head was conducted using Streptococcus thermophilus to produce antioxidant and recover chitin. Fermentation conditions were found to be 10% shrimp head concentration, 5% glucose concentration,1.2%(v/v) inoculum size, and 64 h of incubation time at 42oC to attain an initial pH of 5.00 with response surface method optimization and the actual deproteinization rate obtained was 93.59%. Antioxidant activity in the supernatant fluid increased greatly during fermentation, the DPPH radical scavenging ability of the culture supernatant was about 98.70%. The concent-ration of astaxanthin, phenolic compounds, and free amino acid in the culture supernatant was 1.774 μg/mL, 589.69 μg gallic acid equivalents/mL, and 796.978mg/mL, respectively. Comparison of the FT-IR spectra and X-ray diffraction (XRD) analysis among commercial chitin (CTa), chitin prepared by the S. thermophilus fermentation (CTb), and chitin prepared by chemical treatments (CTc) demonstrated that CTb had the highest degree of deacetylation.