How Does an Extra-Long Freeway Tunnel Influence Driving Performance? A Comparative Study of Driving Simulation

Pengcheng Qin,Jie He,Changjian Zhang,Yuntao Ye,Hao Zhang,Mingnian Wang,Tao Yan 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.9

Extra-long tunnels have adverse effects on driving performance since drivers will be affected by the enclosed, dimly lit, and monotonous environment for a longer time. In the context of the increasing number of extra-long tunnels, this study aims to investigate the effects of extra-long freeway tunnels with a length of 20 km on driving performance using driving simulation tests. Factors including the tunnel environment, driving time, traffic flow, and gender were considered as influencing factors. Performance indicators including the brake reaction time, standard deviation of driving speed, and standard deviation of lateral position were collected. A total of 60 drivers were recruited for the driving simulation study, and the relationships between the driving performance indicators and influencing factors were analyzed by establishing linear mixed models with random intercept. The results demonstrate that driving performance significantly degraded after 5 − 6 min of driving in the extra-long tunnel although drivers were more cautious and presented a better performance when just entering the tunnel. Moderately higher traffic flow could improve driving performance in the extra-long tunnel but not on the open road. Meanwhile, female drivers had better lateral and longitudinal stability in the extra-long tunnel, while no significant difference was witnessed in reaction ability and driving performance on the open road.

Chemerin reverses the malignant phenotype and induces differentiation of human hepatoma SMMC7721 cells

Ming Li,Pengcheng Sun,Kaikai Dong,Ye Xin,Aslee TaiLulu,Qinyu Li,Jing Sun,Min Peng,Ping Shi 대한약학회 2021 Archives of Pharmacal Research Vol.44 No.2

Chemerin exhibits an inhibitory eff ect on hepatocellularcarcinoma; however, the underlying mechanismis unclear. Here, low chemerin expression was confi rmedin samples of liver cancer patients and hepatoma cells. Chemerin altered hepatoma cell morphology but had noeff ect on normal hepatocytes. Chemerin inhibited proliferationof several human hepatoma cell lines. Real-time PCRdetection of hepatocellular carcinoma markers showed thatmRNA levels of albumin and A-type gamma-glutamyltransferase increased whereas those of alpha-fetoprotein,alkaline phosphatase, B-type gamma-glutamyl transferase,insulin-like growth factor II, and human telomerase reversetranscriptase decreased in chemerin-treated SMMC7721cells. Western blotting revealed that chemerin up-regulatedalbumin and vimentin expressions, and downregulated alpha-fetoprotein expression. Phosphorylated STAT3 wassignifi cantly up-regulated, whereas phosphorylated ERKand AKT were signifi cantly downregulated by chemerin. Chemerin decreased phosphorylated ERK and AKT expressionand the cell proliferation induced by PI3K activator 740Y-P but could not signifi cantly alter phosphorylated STAT3expression and the cell growth induced by STAT3 inhibitorNSC74859. In conclusion, chemerin reversed the malignantphenotype and induced SMMC7721 cell diff erentiation byinhibiting MAPK/ERK and PI3K/AKT signaling; growthinhibition by chemerin is not directly related to the JAK/STAT signaling pathway. Our study provides novel evidencethat chemerin could be utilized for liver cancer treatment.

Numerical Analysis of Two-Phase Flow in a Micro-Hydraulic Turbine

Tiejun Chen,Shuaihui Sun,Ye Pang,Pengcheng Guo 한국유체기계학회 2019 International journal of fluid machinery and syste Vol.12 No.4

In many industrial processes such as natural gas processing, seawater desalination et al, there is a large amount of liquid waste pressure energy, which can be converted into electric or mechanical energy by a micro-hydraulic turbine. But its efficiency and stability will deteriorate when the working fluid contains gas. Aiming at improving the hydraulic efficiency of the micro-turbine, the three-dimensional transient two-phase flow model which adopts the shear-stress-transport (SST) model as turbulence model and Eulerian-Eulerian model as two-phase flow model with the commercial code ANSYS-CFX was established and solved to study the two-phase flow characteristics of the micro-hydraulic turbine with fixed guide vane openings under different gas volume fraction (GVF). The numerical simulation results show that the power and efficiency of the turbine decrease by 24% and 21% respectively when the inlet GVF is 0.20. The area of low pressure in each impeller passage increases with the inlet GVF, and the pressure difference between the working and suction surface of the blade decreases. The GVF distribution in impeller passage is asymmetrical, which is caused by the gas-liquid separation in the volute. At the left lower part of impeller passage, the gas accumulates at the suction surface of the blades under the Coriolis force and its GVF reaches 90%. The asymmetrical GVF distribution will result in the asymmetrical pressure distribution in the impeller passage, which leads to the imbalance force on the blades. Moreover, the asymmetrical GVF distribution will reinforce the positive incidence at the lower part of impeller passage, and weaken it at the upper right impeller passage. The volute should be redesigned to ensure the uniform gas distribution at the inlet of each impeller passage.

Effects of Differences in Mechanical Parameters of Media on Mechanical Properties and Failure Form of Composite Samples

Weiqi Wang,Yicheng Ye,Qihu Wang,Xiaoyun Liu,Zhouhao Yuan,Pengcheng Li 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.2

The deformation and failure of composite rock masses at the contact zone can cause serious safety hazards in underground engineering. Therefore, uniaxial compression experiment and numerical studies of composite samples were conducted. Combined with theoretical analysis, the effects of differences in the mechanical properties of two media on the mechanical properties and failure form of composite samples were investigated. The results show that the difference in mechanical properties of two media weakened the strength and elastic modulus of the composite sample and resulted in complex failure form of the sample. Additionally, the peaks of the AE frequencies of the two media occurred successively after the peak stress of the sample. At the macrolevel, the two media failed successively. These effects are more pronounced as the degree of difference in the mechanical properties of the two media increased. The difference in mechanical properties of the two media resulted in uncoordinated deformation and constrained stress near the contact interface, and the difference in Poisson's ratio is the main factor. The influence (enhanced or weakened) of uncoordinated deformation on the mechanical properties of the composite sample is affected by differences in the elastic modulus and Poisson's ratios of the two media.

Long non-coding RNA RP11-6O2.4 indicates poor prognosis and suppresses cell cycle progression through the p38-MAPK signaling pathway in gastric cancer

Yang Feng,Zhiming Fu,Yajun Luo,Wang Tan,Zilin Liu,Pengcheng Ye,Fei Lu,Wanping Xiang,Linghan Tang,Lin Yao,Mengyun Song,Qingmei Huang,Yilun Liu,Jiangwei Xiao 대한독성 유전단백체 학회 2019 Molecular & cellular toxicology Vol.15 No.3

Backgrounds: The role of long non-coding RNAs (lncRNA) in gastric cancer (GC) has been highlighted in studies conducted over the past decade. However, the potential clinical value and the mechanisms of action of RP11-6O2.4 in GC have not been thoroughly elucidated to date. The specific aim of the present study was to assess RP11-6O2.4 and to explore its role in human GC. Methods: Quantitative real-time polymerase chain reaction (qPCR) was performed to analyze the expression levels of RP11-6O2.4 in GC tissues, paired adjacent noncancerous tissues (ANTs) and GC cell lines. In addition, the correlation between RP11-6O2.4 expression and the clinical characteristics and prognosis of patients with GC was statistically analyzed. The effects of RP11- 6O2.4 on the GC cell cycle transformation through the p38-MAPK signaling pathway were explored by flow cytometry, qPCR and Western blot analysis after treatment with SB203580, a p38MAPK specific inhibitor, in vitro. Results: The expression levels of RP11-6O2.4 in GC tissues were significantly lower than the paired ANTs (P<0.05). In addition, RP11-6O2.4 expression was significantly lower in cases with older age, longer maximum tumor diameter, higher ASA grade and deeper invasive depth (P<0.05). RP11-6O2.4 expression was significantly higher in cases with well/middle differentiation than poor/no differentiation; higher in cases without lymph node metastasis than in lymph node metastasis; and higher in cases in stage Ⅰ/Ⅱ than in stage Ⅲ/Ⅳ. An in vitro assay showed that RP11-6O2.4 induced G0/ G1 phase cell cycle arrest, likely by regulating the p38- MAPK signaling pathway. Conclusion: The above mentioned data suggested that RP11-6O2.4 was a tumor-suppressor gene in GC. RP11- 6O2.4 might play an important role in the cell cycle transformation by regulating the p38-MAPK signaling pathway, thereby representing a specific biomarker and a potential molecular target for the treatment of GC.