Behaviour of micropiles in collapsible loess under tension or compression load

Qian, Zeng-Zhen,Lu, Xian-Long,Yang, Wen-Zhi,Cui, Qiang Techno-Press 2014 Geomechanics & engineering Vol.7 No.5

This study examines the behaviour of single micropiles subjected to axial tension or compression load in collapsible loess under in-situ moisture content and saturated condition. Five tension loading tests and five compression loading tests on single micropiles were carried out at a typical loess site of the Loess Plateau in Northwest China. A series of laboratory tests, including grain size distribution, specific gravity, moisture content, Atterberg limits, density, granular components, shear strength, and collapse index, were carried out during the micropile loading tests to determine the values of soil parameters. The loess at the test site poses a severe collapse risk upon wetting. The tension or compression load-displacement curves of the micropiles in loess, under in-situ moisture content or saturated condition, can generally be simplified into three distinct regions: an initial linear, a curvilinear transition, and a final linear region, and the bearing capacity or failure load can be interpreted by the L1-L2 method as done in other studies. Micropiles in loess should be considered as frictional pile foundations though the tip resistances are about 10%-15% of the applied loads. Both the tension and compression capacities increase linearly with the ratio of the pile length to the shaft diameter, L/d. For micropiles in loess under in-situ moisture content, the interpreted failure loads or capacities under tension are 66%-87% of those under compression. However, the prewetting of the loess can lead to the reductions of 50% in the tensile bearing capacity and 70% in the compressive bearing capacity.

Minimizing Average Startup Latency of VMs by Clustering-based Template Caching Scheme in an IaaS System

Zhen Zhou,Shuyu Chen,Mingwei Lin,Guiping Wang,Qian Yang 보안공학연구지원센터(IJUNESST) 2013 International Journal of u- and e- Service, Scienc Vol.6 No.6

Comparative field tests on uplift behavior of straight-sided and belled shafts in loess under an arid environment

Qian, Zeng-zhen,Lu, Xian-long,Yang, Wen-zhi,Cui, Qiang Techno-Press 2016 Geomechanics & engineering Vol.11 No.1

This study elucidates the uplift behaviors of the straight-sided and belled shafts. The field uplift load tests were carried out on 18 straight-sided and 15 belled shafts at the three collapsible loess sites under an arid environment on the Loess Plateau in Northwest China. Both the site conditions and the load tests were documented comprehensively. In general, the uplift load-displacement curves of the straight-sided and belled shafts approximately exhibited an initial linear, a curvilinear transition, and a final linear region, but did not provide a well defined peak or asymptotic value of the load, and therefore their uplift resistances should be interpreted from the load test results using an appropriate criterion. Nine representative uplift resistance interpretation criteria were used to define the "interpreted failure load" for each of the load tests, and all of these interpreted uplift resistances were normalized by the failure threshold, $T_{L2}$, obtained using the $L_1-L_2$ method. These load test data were compared statistically and graphically. For the straight-sided and belled shafts, the normalized uplift load-displacement curves were respectively established by the plots that related the mean interpreted uplift resistance ratio against the mean displacement at the corresponding interpreted criteria, and the comparisons of the normalized load-displacement curves were made. Specific recommendations for the designs of uplift belled and straight-sided shafts in the loess were given, in terms of both capacity and displacement.

Minimizing Average Startup Latency of VMs by an Optimized VM Templates Caching Mechanism Based on K-Medoids Clustering in an IaaS System with Multi-cluster of Servers

Zhen Zhou,Shuyu Chen,Mingwei Lin,Guiping Wang,Qian Yang 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.3

Optimization of Emergency Braking Pedestrian Collision Avoidance for Autonomous Vehicle Fusing the Fuzzy Neural Network with the Genetic Algorithm

Wei Yang,Zhen Zhang,Kongming Jiang,Qian Lei,Ketong Zong 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.7

In order to improve braking performance of the intelligent vehicle, a pedestrian collision avoidance control model for autonomous emergency braking pedestrian (AEB-P) system based on the fuzzy neural network (FNN) and genetic algorithm (GA) theory is proposed. In this research, we construct a backpropagation (BP) feedforward FNN-GA model for the AEB-P system. Aiming to solve the problem that initial training parameters of the FNN model generate randomly, they are optimized by fusing the fuzzy neural network with GA. Simulation results show that training epochs reduce from 800 to 60 and training error changes from [−0.06, +0.06] to [−0.04, +0.04] after optimization. Moreover, the maximum model error lessens from 0.058 to 0.0351 and sample total error decreases from 0.0179 to 0.0068. At last, the proposed scheme is applied to the China New Car Assessment Program (C-NCAP) simulation test scenarios. Output curves of vehicle distance, velocity, and deceleration become smoother and the maximum error decreases from 0.51 m/s2 to 0.26 m/s2 , which verifies the proposed FNN-GA control strategy for AEB-P system is effective and reliable.

A New Quorum-Sensing Inhibitor Attenuates Virulence and Decreases Antibiotic Resistance in Pseudomonas aeruginosa

Yu-Xiang Yang,Zhen-Hua Xu,Yu-Qian Zhang,Jing Tian,Li-Xing Weng,Lian-Hui Wang 한국미생물학회 2012 The journal of microbiology Vol.50 No.6

Quorum sensing (QS) has been a novel target for the treatment of infectious diseases. Here structural analogs of Pseudomonas aeruginosa autoinducer N-acyl homoserine lactone (AHL) were investigated for QS inhibitor (QSI) activity and a novel QSI was discovered, N-decanoyl-L-homoserine benzyl ester (C2). Virulence assays showed that C2 downregulated total protease and elastase activities, as well as the production of rhamnolipid, that are controlled by QS in P.aeruginosa wild-type strain PAO1 without affecting growth. C2 was also shown to inhibit swarming motility of PAO1. Using a microdilution checkerboard method, we identified synergistic interactions between C2 and several antibiotics, tobramycin, gentamycin, cefepime, and meropenem. Data from real-time RT-PCR suggested that C2 inhibited the expression of lasR (29.67%), lasI (21.57%), rhlR (28.20%), and rhlI (29.03%).

Isoindolin-1-ones from the stems of Nicotiana tabacum and their antiviral activities

Guang-Yu Yang,Jia-Meng Dai,Zhen-Jie Li,Jin Wang,Feng-Xian Yang,Xin Liu,Jing Li,Qian Gao,Xue-Mei Li,Yin-Ke Li,Wei-Guang Wang,Min Zhou,Qiu-Fen Hu 대한약학회 2022 Archives of Pharmacal Research Vol.45 No.8

In previous studies, several isoindolin-1-oneanalogs that exhibited signifi cant anti-tobacco mosaic virus(anti-TMV) activities were isolated from Nicotiana tabacum . Since gene-editing mutants provide a new sample for thediscovery of active metabolites, we focused on the stems ofYN-18–23 (a mutant N. tabacum for gene editing with thealkaloid metabolic pathway cultivated by Yunnan TobaccoCompany), which led to the isolation of four new ( 1–4 )and four known ( 5–8 ) isoindolin-1-ones. To the best of ourknowledge, nicindole C ( 3 ) is the fi rst subclass of isoindolin-1-one bearing a pentacyclic ketone, while nicindole D ( 4 )is the fi rst example of isoindolin-1-one bearing a methylpyridin-2-(1 H )-one moiety. Compounds 1–4 were testedfor their anti-TMV activities, and the results revealed thatcompounds 1 , 3 , and 4 exhibited high anti-TMV activities atconcentrations of 20 μM with inhibition rates of 48.6, 42.8,and 71.5%, respectively. These rates are higher than the inhibitionrate of the positive control (33.2%). The mechanisticstudy of compound 4 , which had the highest anti-TMV activityrevealed that increased potentiation of defense-related enzyme activities and downregulation of expression of theNtHsp70 protein may induce resistance in tobacco againstthe viral pathogen TMV. Molecular docking studies alsorevealed that the isoindolin-1-one substructure is fundamentalfor anti-TMV activity. The methyl-pyridin-2-(1 H )-onemoiety in compound 4 and the 2-oxopropyl groups in compounds1 and 3 at the N -2 position may increase inhibitoryactivities. This study of the structure–activity relationshipis helpful for fi nding new anti-TMV activity inhibitors. Tostudy whether the isoindolin-1-ones have broader antiviralactivities, compounds 1–4 were also tested for their antirotavirusactivities. Compound 4 exhibited high anti-rotavirusactivity with a therapeutic index (TI) value of 20.7. This TI value is close to that of the positive control (20.2).

Whole Cell-mediated Biocatalytic Synthesis of Helicid Cinnamylate and Its Biological Evaluation as a Novel Tyrosinase Inhibitor

Rong-ling Yang,Xi Chen,Yu-ye Song,Qian-lin Zhu,Muhammad Bilal,Yu Wang,Zheng Tong,Ting-ting Wu,Zhao-Yu Wang,Hong-zhen Luo,Xiang-jie Zhao,Ting-ting He 한국생물공학회 2022 Biotechnology and Bioprocess Engineering Vol.27 No.3

Tyrosinase inhibitors are clinically effective for treating some dermatological disorders related to melanin hyperpigmentation. Accordingly, the discovery and development of tyrosinase inhibitors have great value in the pharmaceutical and cosmetic industry. Here, a novel tyrosinase inhibitor, 6′-O-cinnamoyl-helicid (helicid cinnamylate) was successfully synthesized by a simple and effective biocatalytic approach with Aspergillus oryzae cells. Investigation of the effects of several key variables on helicid cinnamylate synthesis found that the reaction conversion, reaction rate and regioselectivity reached 99%, 9.40 mM/h and > 99%, respectively, at the optimal conditions with anhydrous acetone as the solvent, whole-cell concentration of 40 mg/mL, and the molar ratio of vinyl cinnamate to helicid of 10 at 45°C. The whole-cells retained 68.87% of its initial activity after reusing for seven batches, indicating a potent application potential in non-aqueous biocatalytic systems. It was worth noting that helicid cinnamylate demonstrated a more potent tyrosinase inhibitory activity with an IC50 value of 3.55 mM than helicid (IC50 = 4.48 mM) and arbutin (IC50 = 5.48 mM), which suggest that helicid cinnamylate could be developed as a more potential tyrosinase inhibitor. In conclusion, this study provides a novel whole-cell catalytic approach for the synthesis of helicid cinnamylate and insight into its application as a tyrosinase inhibitor.

Characterization and uncertainty of uplift load-displacement behaviour of belled piers

Lu, Xian-long,Qian, Zeng-zhen,Zheng, Wei-feng,Yang, Wen-zhi Techno-Press 2016 Geomechanics & engineering Vol.11 No.2

A total of 99 full-scale field load tests at 22 sites were compiled for this study to elucidate several issues related to the load-displacement behaviour of belled piers under axial uplift loading, including (1) interpretation criteria to define various elastic, inelastic, and "failure" states for each load test from the load-displacement curve; (2) generalized correlations among these states and determinations to the predicted ultimate uplift resistances; (3) uncertainty in the resistance model factor statistics required for reliability-based ultimate limit state (ULS) design; (4) uncertainty associated with the normalized load-displacement curves and the resulting model factor statistics required for reliability-based serviceability limit state (SLS) design; and (5) variations of the combined ULS and SLS model factor statistics for reliability-based limit state designs. The approaches discussed in this study are practical and grounded realistically on the load tests of belled piers with minimal assumptions. The results on the characterization and uncertainty of uplift load-displacement behaviour of belled piers could be served as to extend the early contributions for reliability-based ULS and SLS designs.

A combined application of molecular docking technology and indirect ELISA for the serodiagnosis of bovine tuberculosis

Song, Shengnan,Zhang, Qian,Yang, Hang,Guo, Jia,Xu, Mingguo,Yang, Ningning,Yi, Jihai,Wang, Zhen,Chen, Chuangfu The Korean Society of Veterinary Science 2022 Journal of Veterinary Science Vol. No.

Background: There is an urgent need to find reliable and rapid bovine tuberculosis (bTB) diagnostics in response to the rising prevalence of bTB worldwide. Toll-like receptor 2 (TLR2) recognizes components of bTB and initiates antigen-presenting cells to mediate humoral immunity. Evaluating the affinity of antigens with TLR2 can form the basis of a new method for the diagnosis of bTB based on humoral immunity. Objectives: To develop a reliable and rapid strategy to improve diagnostic tools for bTB. Methods: In this study, we expressed and purified the sixteen bTB-specific recombinant proteins in Escherichia coli. The two antigenic proteins, MPT70 and MPT83, which were most valuable for serological diagnosis of bTB were screened. Molecular docking technology was used to analyze the affinity of MPT70, MPT83, dominant epitope peptide of MPT70 (M1), and dominant epitope peptide MPT83 (M2) with TLR2, combined with the detection results of enzyme-linked immunosorbent assay to evaluate the molecular docking effect. Results: The results showed that interaction surface Cα-atom root mean square deviation of proteins (M1, M2, MPT70, MPT83)-TLR2 protein are less than 2.5 A, showing a high affinity. It is verified by clinical serum samples that MPT70, MPT83, MPT70-MPT83 showed good diagnostic potential for the detection of anti-bTB IgG and M1, M2 can replace the whole protein as the detection antigen. Conclusions: Molecular docking to evaluate the affinity of bTB protein and TLR2 combined with ELISA provides new insights for the diagnosis of bTB.