A lightweight and flexible CNT/Fe3O4 composite with high electromagnetic interference shielding performance

Zhuo Chao,Yingying Yu,Fang Lei,Dongmei Hu 한국탄소학회 2021 Carbon Letters Vol.31 No.1

Lightweight and flexible electromagnetic interference (EMI) shielding materials are in great demand for wearable EMI device. In the present work, lightweight and flexible carbon nanotube (CNT)/ferroferric oxide ( Fe3O4) composite film was made through a feasible chemical vapor deposition process for CNT film synthesis, followed by a hydrothermal reduction process for Fe3O4 coating. In the as-prepared composite, CNT film and Fe3O4 particles work as conductive skeleton and strong magnetic particle, respectively. The as-prepared composite film shows a novel EMI shielding effectiveness (SE) of 91 dB in the X-band, a small thickness of 0.09 mm and a low density of 0.86 g/cm3, which is superior to most of the carbonbased EMI materials.

Two New Phenolic Compounds from the Fruiting Bodies of Ganoderma tropicum

Hu, Li-Li,Ma, Qing-Yun,Huang, Sheng-Zhuo,Guo, Zhi-Kai,Guo, Jian-Chun,Dai, Hao-Fu,Zhao, You-Xing Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.3

Chemical investigation of the fruiting bodies of Ganoderma tropicum led to the isolation of two new phenolic compounds, ganodermatropins A (1) and B (2). Their structures were elucidated by spectroscopic techniques (MS, 1D and 2D NMR). Ganodermatropin A exhibited antimicrobial activity against Staphylococcus aureus.

LiCOI1 mediates the biosynthesis of monoterpenes induced by methyl jasmonate in Lilium ‘Siberia’

Leng Zhuo,Li Ying-Ying,Fu Yu-Chen,Wu Jing,Leng Ping-Sheng,Hu Zeng-Hui 한국원예학회 2024 Horticulture, Environment, and Biotechnology Vol.65 No.2

As a volatile hormone signal, methyl jasmonate (MeJA) can regulate the biosynthesis of secondary metabolites. But in f l oral fragrance, the eff ect and mechanisms of MeJA on monoterpenes, the major components of many plants, are largely unknown. In this paper, we measured the release of monoterpenes from petals of Lilium ‘Siberia’ after MeJA treatment, as well as the expressions of monoterpene pathway genes and Lilium coronatine-insensitive ( LiCOI1 ) gene. Then the LiCOI1 gene was cloned, and using virus-induced gene silencing (VIGS) technology, its function in monoterpene biosynthesis in response to MeJA was validated. The results showed that MeJA signifi cantly improved the release amounts of myrcene, ocimene, and linalool. The expression levels of synthase genes [ Lilium myrcene synthase ( LiMYS ), Lilium ocimene syn thase ( LiOCS ), as well as Lilium linalool synthase ( LiLIS )], two pathway genes [ Lilium 1-deoxy-D-xylulose 5-phosphate synthase ( LiDXS ) and Lilium 1-deoxy-D-xylulose-5-phosphate reductoisomerase ( LiDXR )] were enhanced. Moreover, the LiCOI1 gene exhibited a remarkably increased expression level, which suggested its signaling role. Based on the analysis, the full length of LiCOI1 gene was 1809 bp, whose deduced protein contained 602 amino acids and was mainly located in the nucleus. Silencing the expression of LiCOI1 in petals signifi cantly depressed not only the gene expressions of LiMYS , LiOCS , LiLIS , LiDXS , and LiDXR , but also the release amounts of myrcene, ocimene, and linalool. These results confi rm that LiCOI1 plays an important signaling role in MeJA-induced enhancement of monoterpene biosynthesis in Lilium ‘Siberia’.

Distributed Cooperative Path Planning for Tracking Ground Moving Target by Multiple Fixed-wing UAVs via DMPC-GVD in Urban Environment

Chaofang Hu,Zhuo Meng,Ge Qu,신효상,Antonios Tsourdos 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.2

In this paper, a real-time distributed path planning method is developed for cooperatively tracking ground moving target in urban by multiple fixed-wing unmanned aerial vehicles (UAVs). For reasons of changeable movement of target, the commanded speed and turning rate of each UAV are both taken as control input variables. In urban environment, buildings may occlude the line of sight of on-board sensor. Hence the target coverage degree is proposed as objective function instead of distance. To save energy of UAV system as much as possible, the control input cost and sensor energy consumption are also taken as objectives. For preemptive priority requirement, the objective functions are fuzzified and the satisfactory degree order is designed to model priority. To guarantee the feasibility of solution, the varying domain is introduced to replace the strict order constraint. On this basis, generalized varying domain (GVD) method is developed to balance optimization and priority. In terms of the maneuverability of UAVs, the diverse constraints are considered, including real speed and turning rate, control input saturation, collision avoidance between UAVs, and obstacle avoidance between UAV and buildings. Consequently, distributedmodel predictive control (DMPC) strategy is designed to calculate the optimal path of each UAV, where the state information in finite period of UAV is transferred to the adjacent ones. The simulations show the effectiveness of proposed method by comparing with hierarchical optimization (HO).

Gap junction blockage promotes cadmium-induced apoptosis in BRL 3A derived from Buffalo rat liver cells

Di Hu,Hui Zou,Tao Han,Junze Xie,Nannan Dai,Liling Zhuo,Jianhong Gu,Jianchun Bian,Yan Yuan,Xuezhong Liu,Zongping Liu 대한수의학회 2016 Journal of Veterinary Science Vol.17 No.1

Gap junctions mediate direct communication between cells; however, toxicological cascade triggered by nonessential metals can abrogate cellular signaling mediated by gap junctions. Although cadmium (Cd) is known to induce apoptosis in organs and tissues, the mechanisms that underlie gap junction activity in Cd-induced apoptosis in BRL 3A rat liver cells has yet to be established. In the present study, we showed that Cd treatment decreased the cell index (a measure of cellular electrical impedance) in BRL 3A cells. Mechanistically, we found that Cd exposure decreased expression of connexin 43 (Cx43), increased expression of p-Cx43 and elevated intracellular free Ca2+ concentration, corresponding to a decrease in gap junctional intercellular communication. Gap junction blockage pretreatment with 18b-glycyrrhizic acid (GA) promoted Cd-induced apoptosis, involving changes in expression of Bax, Bcl-2, caspase-3 and the mitochondrial transmembrane electrical potential (Δym). Additionally, GA was found to enhance ERK and p38 activation during Cd-induced activation of mitogen-activated protein kinases, but had no significant effect on JNK activation. Our results indicated the apoptosis-related proteins and the ERK and p38 signaling pathways may participate in gap junction blockage promoting Cd-induced apoptosis in BRL 3A cells.

Poly(vinyl alcohol) Fibers with Excellent Mechanical Properties Produced by Reinforcement of Single-walled Graphene Oxide Nanoribbons with Complete Morphology Obtained by Freezedrying

Di Hu,Chao Xiao,Xia Wang,Xike Xiong,Jun Sun,Qiqi Zhuo,Jianjun Wang,Chuanxiang Qin,Lixing Dai 한국섬유공학회 2019 Fibers and polymers Vol.20 No.12

Nanofiller reinforcement is an effective approach to realize high performance of regular synthetic fibers. In thispaper, graphene oxide nanoribbons (GONRs) with complete morphology were prepared via unzipping single-walled carbonnanotubes (SWCNTs) through long-time freeze-drying after oxidation. GONRs derived from SWCNTs (SGONRs) did notneed any modification and could be directly added to poly(vinyl alcohol) (PVA) to form uniform dispersions and thencontinuous fibers were fabricated using wet spinning and hot-drawing. SGONRs provided abundant hydrogen bondinginteraction with PVA chains, so SGONRs could not only obviously improve the dispersibility in PVA, but also enhance themechanical properties of the composites. The tensile strength of PVA/SGONRs composite fibers with 0.4 wt% loading ofSGONRs reach 1032 MPa, improved by 121 % compared with PVA/SWCNTs fiber, and by 200 % with PVA fiber,respectively.

Two New Phenolic Compounds from the Fruiting Bodies of Ganoderma tropicum

Li-Li Hu,Qing-Yun Ma,Sheng-Zhuo Huang,Zhi-Kai Guo,Jianchun Guo,Hao Fu Dai,You-Xing Zhao 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.3

Chemical investigation of the fruiting bodies of Ganoderma tropicum led to the isolation of two new phenolic compounds, ganodermatropins A (1) and B (2). Their structures were elucidated by spectroscopic techniques (MS, 1D and 2D NMR). Ganodermatropin A exhibited antimicrobial activity against Staphylococcus aureus.

Ursolic Acid-induced Apoptosis in K562 Cells Involving Upregulation of PTEN Gene Expression and Inactivation of the PI3K/Akt Pathway

Bin Wu,Zhuo-gang Liu,Xu Wang,Zuo-fei Chi,Rong Hu,Rong Zhang,Wei Yang 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.3

Ursolic acid (UA), a pentacyclic triterpenoid derived from a variety of medicinal plants, exhibits potent anticancer activity against many types of cancer cells. However, the anticancer mechanism of UA is not clearly understood. Suppression of phosphatase and a tensin homolog deleted on chromosome 10 (PTEN) gene expression leading to activation of the phosphatidylinositol-3-OH kinase (PI3K)/Akt pathway has been observed in many cancers including leukemia, making the PTEN gene and PI3K/Akt pathway a central target for cancer therapy. Here, we demonstrated that UA was able to inhibit growth, induce apoptosis in a human chronic myelogenous leukemia cell line (K562 cells) via upregulation of PTEN gene expression, inhibit Akt kinase activity, change mitochondrial transmembrane potential and reduce the release of cytochrome c and the activity of caspases. These results suggest that UA may elicit its strong antitumor effects via upregulation of the PTEN gene and inhibition of the PI3K/Akt pathway.

Exploring the Fuel Economy Potential of ISG Hybrid Electric Vehicles through Dynamic Programming

Guoqiang Ao,Hu Zhong,Jiaxi Qiang,Lin Yang,Bin Zhuo 한국자동차공학회 2007 International journal of automotive technology Vol.8 No.6

Hybrid electric vehicles (HEV) combined with more than one power sources have great potential to improve fuel economy and reduce pollutant emissions. The Integrated Starter Generator (ISG) HEV researched in this paper is a two energy sources vehicle, with a conventional internal combustion engine (ICE) and an energy storage system (batteries). In order to investigate the potential of diesel engine hybrid electric vehicles in fuel economy improvement and emissions reduction, a Dynamic Programming (DP) based supervisory controller is developed to allocate the power requirement between ICE and batteries with the objective of minimizing a weighted cost function over given drive cycles. A fuel-economy-only case and a fuel & emissions case can be achieved by changing specific weighting factors. The simulation results of the fuel-economy-only case show that there is a 45.1% fuel saving potential for this ISG HEV compared to a conventional transit bus. The test results present a 39.6% improvement in fuel economy which validates the simulation results. Compared to the fuel-economy-only case, the fuel & emissions case further reduces the pollutant emissions at a cost of 3.2% and 4.5% of fuel consumption with respect to the simulation and test result respectively.

Shear Behavior of Corroded Post-Tensioned Prestressed Concrete Beams with Full/Insufficient Grouting

Lei Wang,Zhuo Hu,Ju Yi,Lizhao Dai,Yafei Ma,Xuhui Zhang 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.6

This paper experimentally studied the shear behavior of corroded post-tensioned prestressed concrete beams with full grouting. The effects of insufficient grouting in shear span on the shear behavior were also investigated. Eight beams were fabricated and divided into two groups: four beams with full grouting and four beams with insufficient grouting. Three beams in each group were subjected to accelerated corrosion. All beams were tested to failure in four-point loading. Experimental data on shear cracking, load-deflection response, shear strength and failure modes were presented. Results showed that strand corrosion accelerated the formation and propagation of diagonal crack. Insufficient grouting decreased the number of diagonal cracks. Strand corrosion degraded the post-cracking stiffness and shear strength. Insufficient grouting aggravated the propagation of diagonal crack and the degradation of post-cracking stiffness. The shear strength of corroded beam with 31.7% corrosion loss decreased by 15.44% as compared to that of the uncorroded beam. Strand corrosion loss less than 31.7% did not change the shear compression failure mode in fully grouted beams. The failure modes of locally ungrouted beams changed from shear compression failure to rupture of wires as the corrosion loss exceeded 39.6%.