Face Stability Analysis of Slurry Shield Tunnels in Rock–Soil Interface Mixed Ground

Ping Lu,Da-Jun Yuan,Jian Chen,Dalong Jin,Jun Wu,Weiping Luo 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.6

When shield tunneling in rock-soil interface (RSI) mixed ground, maintaining the stability of the tunnel face is very challenging. This study aims at the investigation of the face stability of slurry shield tunnels in RSI mixed ground. A new apparatus was developed to simulate pressurized slurry supporting the tunnel face in centrifuge tests. The progressive failure of the tunnel face was triggered with slow decrease of slurry pressure. With two equivalent model tunnels of circular shape and semicircular shape, the variations of soil (water) pressure and the displacement field in front of the tunnel can be obtained simultaneously. The face failure was found to be a local collapse in the upper soil layer. The limit support pressure was picked out at the sudden change of the measured soil or water pressures. Then the classical wedge-prism model was introduced and modified to calculate the limit support pressure for slurry shield tunnels in RSI mixed ground considering the partial collapse. Numerical analysis was applied to verify the theoretical analysis and sensitivity analysis was performed to estimate the influence of different parameters on the theoretical solutions.

An Efficient Load Balancing Scheme for Multi-Gateways in Wireless Mesh Networks

( Jun Ping Liu ),( Sang Hwa Chung ) 한국정보처리학회 2013 Journal of information processing systems Vol.9 No.3

In Wireless Mesh Networks (WMNs), we usually deploy multiple Internet Gateways (IGWs) to improve the capacity of WMNs. As most of the traffic is oriented towards the Internet and may not be distributed evenly among different IGWs, some IGWs may suffer from bottleneck problem. To solve the IGW bottleneck problem, we propose an efficient scheme to balance the load among different IGWs within a WMN. Our proposed load-balancing scheme consists of two parts: a traffic load calculation module and a traffic load migration algorithm. The IGW can judge whether the congestion has occurred or will occur by using a linear smoothing forecasting method. When the IGW detects that the congestion has occurred or will occur, it will firstly select another available IGW that has the lightest traffic load as the secondary IGW and then inform some mesh routers (MPs) which have been selected by using the Knapsack Algorithm to change to the secondary IGW. The MPs can return to their primary IGW by using a regression algorithm. Our Qualnet 5.0 experiment results show that our proposed scheme gives up to 18% end-to-end delay improvement compared with the existing schemes.

Silencing of long noncoding RNA HOXA11-AS inhibits the Wnt signaling pathway via the upregulation of HOXA11 and thereby inhibits the proliferation, invasion, and self-renewal of hepatocellular carcinoma stem cells

Jun-Cheng Guo,Yi-Jun Yang,Jin-Fang Zheng,Jian-Quan Zhang,Min Guo,Xiang Yang,Xiang-Ling Jiang,Li Xiang,You Li,Huang Ping,Liu Zhuo 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Hepatocellular carcinoma (HCC) is a major cause of cancer-related deaths, but its molecular mechanisms are not yet well characterized. Long noncoding RNAs (lncRNAs) play crucial roles in tumorigenesis, including that of HCC. However, the role of homeobox A11 antisense (HOXA11-AS) in determining HCC stem cell characteristics remains to be explained; hence, this study aimed to investigate the effects of HOXA11-AS on HCC stem cell characteristics. Initially, the expression patterns of HOXA11-AS and HOXA11 in HCC tissues, cells, and stem cells were determined. HCC stem cells, successfully sorted from Hep3B and Huh7 cells, were transfected with short hairpin or overexpression plasmids for HOXA11-AS or HOXA11 overexpression and depletion, with an aim to study the influences of these mediators on the self-renewal, proliferation, migration, and tumorigenicity of HCC stem cells in vivo. Additionally, the potential relationship and the regulatory mechanisms that link HOXA11-AS, HOXA11, and the Wnt signaling pathway were explored through treatment with Dickkopf-1 (a Wnt signaling pathway inhibitor). HCC stem cells showed high expression of HOXA11-AS and low expression of HOXA11. Both HOXA11-AS silencing and HOXA11 overexpression suppressed the self-renewal, proliferation, migration, and tumorigenicity of HCC stem cells in vivo, as evidenced by the decreased expression of cancer stem cell surface markers (CD133 and CD44) and stemness-related transcription factors (Nanog, Sox2, and Oct4). Moreover, silencing HOXA11-AS inactivated the Wnt signaling pathway by decreasing the methylation level of the HOXA11 promoter, thereby inhibiting HCC stem cell characteristics. Collectively, this study suggested that HOXA11-AS silencing exerts an antitumor effect, suppressing HCC development via Wnt signaling pathway inactivation by decreasing the methylation level of the HOXA11 promoter.

From Gene Map to Gene Expression Map: The Second Phase of the Chinese Superhybrid Rice Genome Project (SRGP)

Jun Yu,Song Nian Hu,Jun Wang,Gane K. S. Wong,Wei Lin,Xing Wang Deng,Li Huang Zhu,Meng Liang Cao,Long Ping Yuan,Jian Wang,Huan Ming Yang 한국육종학회 2002 한국육종학회 학술발표회 발표요지 Vol.34 No.2

Study on Nano-Metal Oxide and Carbon Nanotube Composites on Thermal Decomposition of Potassium Perchlorate

Ping-An Liu,Meng-Jun Wang,Lu Wang,Jun Wang,Ting Wang 대한화학회 2019 Bulletin of the Korean Chemical Society Vol.40 No.4

In this study, novel carbon nanotube (CNT) and transition-metal oxides (TMOs) nanoparticle catalysts were prepared and their effects on the thermal decomposition of potassium perchlorate (KP) were investigated. Nanocatalysts have been widely studied because of their excellent properties, such as the high surface energies of nanoparticles and their ease of agglomeration adversely affect their catalytic performances. Good dispersion is the key to good nanocatalytic activity. The composite catalysts were prepared by loading a nanocatalyst on CNTs; this improves nanoparticle dispersion, promotes electron transfer during the reaction, and increases the catalytic effect. Different types of CNT-based composite catalysts and their corresponding single nanocatalysts were each added to KP. The effects of the catalysts on the thermal decomposition of KP were studied using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The activity of each catalyst was evaluated on the basis of the changes in the thermal decomposition peaks and the apparent decomposition heats. The results show that the activity of a composite catalyst in KP thermal decomposition is much higher than that of its corresponding single nanocatalyst.

Effect of Coagulating Agents on Lignin and Sugar Contents in Acid Prehydrolysis Liquor

Chao-Jun Wu,Dong-Mei Yu,Shu-Ping Li,Li-Juan Bing,Rui-Ping Tong 한국펄프·종이공학회 2016 한국펄프·종이공학회 학술발표논문집 Vol.2016 No.10

Hypoglycemic triterpenes from <i>Gynostemma pentaphyllum</i>

Wang, Jun,Ha, Thi Kim Quy,Shi, Yan-Ping,Oh, Won Keun,Yang, Jun-Li Elsevier 2018 Phytochemistry Vol.155 No.-

<P><B>Abstract</B></P> <P>To search for bioactive gypenosides and their analogues, a saponin enriched fraction and its hydrolyzate from <I>Gynostemma pentaphyllum</I> were phytochemically investigated. Fractionation by diverse chromatographic methods, including HPLC, Sephadex LH-20, silica gel, and C18 reverse phase silica gel, led to the isolation and purification of twelve triterpenes, including five undescribed and seven known. The chemical structures of all compounds were determined as analyzed by nuclear magnetic resonance (NMR), high resolution mass spectrometry (HR-MS), infrared spectrum (IR), optical rotation, and chemical transformations. Among all isolates, nine compounds possessed a rare dammarane triterpenoid framework with A-ring modified. The relative configurations of three compounds were determined by 2D NMR for the first time. The absolute configurations of four compounds were determined by the modified Mosher's method. Two of all isolated compounds significantly enhanced 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-D-glucose (2-NBDG) uptake and Glucose Transporter 4 (GLUT4) translocation via activating the AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) signaling pathway. This study provided the potential candidates for the development of antidiabetic agents.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Gynostemma pentaphyllum</I> is a traditional medicinal and edible plant in China. </LI> <LI> Five undescribed triterpenes were isolated. </LI> <LI> The modified Mosher's method was used to determine the absolute configurations. </LI> <LI> Their hypoglycemic activity was evaluated in differentiated 3T3-L1 adipocytes. </LI> <LI> This study provided the potential candidates for antidiabetic agents. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Five undescribed and nine known triterpenes were isolated from the hydrolyzate and extract of <I>Gynostemma pentaphyllum.</I> Their hypoglycemic activity was evaluated.</P> <P>[DISPLAY OMISSION]</P>

Studies on meat color, myoglobin content, enzyme activities, and genes associated with oxidative potential of pigs slaughtered at different growth stages

Qin Ping Yu,Ding Yuan Feng,Juan Xiao,Fan Wu,Xiao Jun He,Min Hao Xia,Tao Dong,Yi Hua Liu,Hui Ze Tan,Shi Geng Zou,Tao Zheng,Xian Hua Ou,Jian Jun Zuo 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.12

Objective: This experiment investigated meat color, myoglobin content, enzyme activities, and expression of genes associated with oxidative potential of pigs slaughtered at different growth stages. Methods: Sixty 4-week-old Duroc×Landrace×Yorkshire pigs were assigned to 6 replicate groups, each containing 10 pigs. One pig from each group was sacrificed at day 35, 63, 98, and 161 to isolate longissimus dorsi and triceps muscles. Results: Meat color scores were higher in pigs at 35 d than those at 63 d and 98 d (p<0.05), and those at 98 d were lower than those at 161 d (p<0.05). The total myoglobin was higher on 161 d compared with those at 63 d and 98 d (p<0.05). Increase in the proportions of metmyoglobin and deoxymyoglobin and a decrease in oxymyoglobin were observed between days 35 and 161 (p<0.05). Meat color scores were correlated to the proportion of oxymyoglobin (r = 0.59, p<0.01), and negatively correlated with deoxymyoglobin and metmyoglobin content (r = –0.48 and –0.62, p<0.05). Malate dehydrogenase (MDH) activity at 35 d and 98 d was higher than that at 161 d (p<0.05). The highest lactate dehydrogenase/MDH ratio was achieved at 161 d (p<0.05). Calcineurin mRNA expression decreased at 35 d compared to that at 63 d and 98 d (p<0.05). Myocyte enhancer factor 2 mRNA results indicated a higher expression at 161 d than that at 63 d and 98 d (p<0.05). Conclusion: Porcine meat color, myoglobin content, enzyme activities, and genes associated with oxidative potential varied at different stages.

Senescence as A Consequence of Ginsenoside Rg₁ Response on K562 Human Leukemia Cell Line

Liu, Jun,Cai, Shi-Zhong,Zhou, Yue,Zhang, Xian-Ping,Liu, Dian-Feng,Jiang, Rong,Wang, Ya-Ping Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Aims and Background: Traditional chemotherapy strategies for human leukemia commonly use drugs based on cytotoxicity to eradicate cancer cells. One predicament is that substantial damage to normal tissues is likely to occur in the course of standard treatments. Obviously, it is urgent to explore therapies that can effectively eliminate malignant cells without affecting normal cells. Our previous studies indicated that ginsenoside $Rg_1$ ($Rg_1$), a major active pharmacological ingredient of ginseng, could delay normal hematopoietic stem cell senescence. However, whether $Rg_1$ can induce cancer cell senescence is still unclear. Methods: In the current study, human leukemia K562 cells were subjected to $Rg_1$ exposure. The optimal drug concentration and duration with K562 cells was obtained by MTT colorimetric test. Effects of $Rg_1$ on cell cycle were analyzed using flow cytometry and by SA-${\beta}$-Gal staining. Colony-forming ability was measured by colony-assay. Telomere lengths were assessed by Southern blotting and expression of senescence-associated proteins P21, P16 and RB by Western blotting. Ultrastructural morphology changes were observed by transmission electron microscopy. Results: K562 cells demonstrated a maximum proliferation inhibition rate with an $Rg_1$ concentration of $20{\mu}\;mol{\cdot}L^{-1}$ for 48h, the cells exhibiting dramatic morphological alterations including an enlarged and flat cellular morphology, larger mitochondria and increased number of lysosomes. Senescence associated-${\beta}$-galactosidase (SA-${\beta}$-Gal) activity was increased. K562 cells also had decreased ability for colony formation, and shortened telomere length as well as reduction of proliferating potential and arrestin $G_2$/M phase after $Rg_1$ interaction. The senescence associated proteins P21, P16 and RB were significantly up-regulated. Conclusion: Ginsenoside $Rg_1$ can induce a state of senescence in human leukemia K562 cells, which is associated with p21-Rb and p16-Rb pathways.

Microstructure, electrical conductivity and mechanical properties of graphitization carbon foam derived from epoxy resin modified with coal tar pitch

Yang Ping Jun,Li Tie Hu,Li Hao,Dang A. Lei 한국탄소학회 2024 Carbon Letters Vol.34 No.3

In this study, the aromatic carbon content of epoxy resin (EP) increased via carbon tar pitch (CTP) modification, and the CTP occurred self-polymerization reaction. The carboxyl and hydroxyl groups of CTP and the hydroxyl and carboxyl groups of EP occurred chemical cross-linking reaction. CTP and graphitization treatment promoted EP CF carbon crystal growth. The graphitization degree of pure EP CF and 40 wt% CTP modified EP CF are 8.42% and 44.21%, respectively. With the increase CTP content, the cell size, ligament junction and density of graphitization modified EP CF gradually increased, while the number of pores and cells gradually decreased. The cell size, ligament junction size and density of 40 wt% CTP modified graphitization EP CF increased to 1200 μm, 280 μm and 0.5033 g/cm3, respectively. EP CF exhibits entangling carbon ribbon and isotropic amorphous carbon. The 40 wt% CTP modified EP CF is composed of evenly distributed amorphous resin carbon and graphite domain CTP carbon. The graphitization modified EP CF improved electrical conductivity, and the electrical conductivity of 40 wt% CTP modified EP CF is 126.6 S/m. The compressive strength can be decided by EP carbon strength and its char yield, and graphitization 40 wt% CTP modified EP CF reached 4.9 MPa. This study provides some basis for preparation and application of CTP modified EP CF.