Research on non-destructive testing technology for existing bridge pile foundations

Zhang, Xue-feng,Ni, Ying-sheng,Song, Chunxia,Xu, Dong Techno-Press 2020 Structural monitoring and maintenance Vol.7 No.1

Pile foundations of existing bridges lie in soil and water environment for long term and endure relatively heavy vertical loads, thus prone to damages, especially after stricken by external forces, such as earthquake, collision, soil heap load and etc., and the piles may be injured to certain degrees as well. There is a relatively complete technical system for quality inspection of new bridge pile foundations without structures on the top. However, there is no mature technical standard in the engineering community for the non-destructive testing technology specific to the existing bridge pile foundations. The quality of bridge pile foundations has always been a major problem that plagues bridge maintenance. On the basis of many years' experiences in test engineering and theoretical studies, this study developed a new type of detection technology and equipment for the existing bridge piles.

Characterization of Marinilongibacter aquaticus gen. nov., sp. nov., a unique marine bacterium harboring four CRISPR-Cas systems in the phylum Bacteroidota

Zhang Dao-Feng,Yao Yu-Fang,Xue Hua-Peng,Fu Zi-Yue,Zhang Xiao-Mei,Shao Zongze 한국미생물학회 2022 The journal of microbiology Vol.60 No.9

A novel bacterium, designated YYF0007T, was isolated from an agar-degrading co-culture. The strain was found harboring four CRISPR-Cas systems of two classes in the chromosome and subsequently subjected to a study on polyphasic taxonomy. Pairwise analyses of the 16S rRNA gene sequences indicated that strain YYF0007T had highest 16S rRNA gene sequence similarity (92.2%) to Jiulongibacter sediminis JN- 14-9T. The phylogenomic trees based on the 16S rRNA gene and 269 single-copy orthologous gene clusters (OCs) indicated that strain YYF0007T should be recognized as a novel genus of the family Spirosomaceae. The cells were Gramstain- negative, nonmotile, strictly aerobic, and straight long rods with no flagellum. Optimum growth occurred at 28°C and pH 7.0 with the presence of NaCl concentration 1.0–3.0% (w/v). The strain showed oxidase and catalase activities. The major fatty acids were C16:1ω5c, iso-C15:0 and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c). The predominant isoprenoid quinone was MK-7. The complete genome size was 4.64 Mb with a DNA G + C content of 44.4%. Further typing of CRISPR-Cas systems in the family Spirosomaceae and the phylum Bacteroidota indicated that it was remarkable for strain YYF0007T featured by such a set of CRISPR-Cas systems. This trait highlights the applications of strain YYF- 0007T in studies on the evolutionary dynamics and bacterial autoimmunity of CRISPR-Cas system as a potential model. The name Marinilongibacter aquaticus gen. nov., sp. nov. is proposed, and the type strain is YYF0007T (= MCCC 1K06017T = GDMCC 1.2428T = JCM 34683T).

Experimental Investigation of Measurement Error in Networked Resistors Arrays Based on Zero Potential Method

Xue-Feng Zhang,Anjiang Cai,Yulong Zhao 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.4

This paper provides a comprehensive study on the zero potential method for restriction of the crosstalk-based measurement error in network resistor arrays. We introduce four circuits with different architectures based on the zero potential method to comparatively study the effect of the switches on-resistance on the measurement error. Moreover, the effect of the operational amplifiers with different specifications on the measurement error will be investigated. The results show that the measurement error introduced by the onresistance of the switches can be effectively suppressed by inserting a buffer between the sensing elements and the switches on each driven electrode, and utilizing the virtual ground of the trans-impedance amplifier on each scanned electrode. We will show that, the efficiency of the circuits on elimination of the measurement error may be improved by employing high precision operational amplifiers.

Reliable control of magnetic vortex chirality in asymmetrically optimized magnetic nanodisk

Zhang Huanhuan,Yu Hai,Zhang Xue-Feng,Yang Xiao-Xue,Shim Je-Ho,Ma Xiao-Ping,Piao Hong-Guang 한국물리학회 2022 Current Applied Physics Vol.43 No.-

Magnetic vortex has attracted attention in the field of information storage because their topological spin structures with chiral bistable states. If the vortex core polarity and vortex circulation sense can be controlled simultaneously in a nanodisk, which will be more beneficial to realize the multi-bit ultrahigh density storage. In this paper, a reliable control scheme for magnetic vortex chirality is proposed by optimizing the structure of Pac- Man-like nanodisk. The results show that the polarity and circulation of the vortex can be controlled simultaneously by changing the direction of the global magnetic field, and even the chiral states of the vortex can be determined by detecting the stray field distribution on the surface of the nanodisk. The optimized Pac-Man-like nanodisk provide an experimental method for the control and detection of magnetic vortex chirality, which will be beneficial to the realization of multi-bit magnetic storage or magnetic logic technology in the future.

Study on safety early-warning model of bridge underwater pile foundations

Xue-feng Zhang,Chun-xia Song Techno-Press 2023 Structural monitoring and maintenance Vol.10 No.2

The health condition of of deep water high pile foundation is vital to the safe operation of bridges. However, pier foundations are vulnerable to damage in deep water due to exposure to sea torrents and corrosive environments over an extended period. In this paper, combined with aninvestigation and analysis of the typical damage characteristics of main pier group pile foundations, we study the safety monitoring and real-time early warning technology of the deep water high pile foundations, we propose an early warning index item and early warning threshold of deep water high pile foundation by utilizing a numerical simulation analysis and referring to domestic and foreign standards and literature. First, we combine the characteristics of structures and draw on more mature evaluation theories and experience in civil engineering-related fields such as dam and bridge engineering. Then, we establish a scheme consisting of a Early Warning Index Systemand evaluation model based on the analytic hierarchy process and constant weight evaluation method and apply the research results to a project based on the Jiashao bridge in Zhejiang province, China. Finally, we verify the rationality and reliability of the Early Warning Index Systemof the Deep Water High Pile Foundations.

Enhancement of transglutaminase production in Streptomyces mobaraensis DSM 40587 by non-nutritional stress conditions: Effects of heat shock, alcohols, and salt treatments

Lili Zhang,Lanwei Zhang,Huaxi Yi,Ming Du,Yingchun Zhang,Xue Han,Zhen Feng,Jingyan Li,Yuehua Jiao,Yanhe Zhang,Chunfeng Guo 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.7

Stress-mediated bioprocess is a strategy designed to enhance biological target productivity. In this study,an attempt was made to enhance transglutaminase (TGase) production by Streptomyces mobaraensis by using different stress conditions including heat shock, alcohols and salt stress. Results showed that the effects of stress on TGase production depended on the type applied. For heat shock, TGase production (1.32 U/ml) was recorded maximum in the culture treated at 48 h post inoculation in water bath at 60 oC for 1 min. For alcohols treatment, the maximum activity of TGase (1.77 and 1.75 U/ml) was obtained when 3% methanol was added into the medium at 0 or 24 h of fermentation. However, a 3.5-fold increased production of TGase (3.8 U/ml) was observed in the medium supplemented with 0.2mol/l MgCl2 compared with the basic medium at the beginning of fermentation. In conclusion, TGase production from S. mobaraensis was improved by heat shock, methanol and salt stress treatments, MgCl2 stress was the most effective.

Lentivirus-mediated silencing of the PTC1 and PTC2 genes promotes recovery from spinal cord injury by activating the Hedgehog signaling pathway in a rat model

Ya-Dong Zhang,Zhong-Sheng Zhu,Dong Zhang,Zhen Zhang,Bin Ma,Shi-Chang Zhao,Feng Xue 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

This study aimed to investigate the effect of Patched-1 (PTC1) and PTC2 silencing in a rat model, on Hedgehog (Hh) pathwaymediated recovery from spinal cord injury (SCI). An analytical emphasis on the relationship between the sonic hedgehog (Shh) pathway and nerve regeneration was explored. A total of 126 rats were divided into normal, sham, SCI, negative control (NC), PTC1-RNAi, PTC2-RNAi and PTC1/PTC2-RNAi groups. The Basso, Beattie and Bresnahan (BBB) scale was employed to assess hind limb motor function. Quantitative real-time polymerase chain reaction and western blotting were performed to examine the mRNA and protein levels of PTC1, PTC2, Shh, glioma-associated oncogene homolog 1 (Gli-1), Smo and Nestin. Tissue morphology was analyzed using immunohistochemistry, and immunofluorescent staining was conducted to detect neurofilament protein 200 (NF-200) and glial fibrillary acidic protein (GFAP). The PTC1/PTC2-RNAi group displayed higher BBB scores than the SCI and NC groups. Shh, Gli-1, Smo and Nestin expression levels were elevated in the PTC1/PTC2-RNAi group. PTC1 and PTC2 mRNA and protein expression was lower in the PTC1/PTC2-RNAi group than in the normal, sham and SCI groups. Among the seven groups, the PTC1/PTC2-RNAi group had the largest positive area of NF-200 staining, whereas the SCI group exhibited a larger GFAP-positive area than both the normal and the sham groups. The Shh pathway may provide new insights into therapeutic indications and regenerative recovery tools for the treatment of SCI. Activation of the Hh signaling pathway by silencing PTC1 and PTC2 may reduce inflammation and may ultimately promote SCI recovery.

Rapid quantitative typing spectra model for distinguishing sweet and bitter apricot kernels

Xue Huang,Jiayi Xu,Feng Gao,Hongyan Zhang,Ling Guo 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.9

Amygdalin content in apricot kernels is an essential factor in the rapid and nondestructive identification of sweet or bitter apricot kernels through spectroscopy. Now, amygdalin content has been determined by high-performance liquid chromatography and near-infrared spectral database to construct a model so that the sweet or bitter apricot kernels could be identified and classified. Principal component analysis–K-nearest neighbor classification algorithm combined with multivariate scattering correction pretreatment method could distinguish sweet and bitter apricot kernels in the wavelength range of 1650–1740 nm with 98.3% accuracy and apricot kernel species with 96.3% recognition rate in the full wavelength spectrum. Furthermore, prediction of amygdalin content in bitter and sweet apricot kernels by partial least squares model was superior to that by back-propagation neural network model. This study provides a theoretical basis for quality identification of apricot kernel quality, as well as a method for nondestructive and rapid detection of sweet and bitter apricot kernels.

Food Microbiology and Biotechnology : Gene Cloning and Characterization of an α-Amylase from Alteromonas macleodii B7 for Enteromorpha Polysaccharide Degradation

( Xue Feng Han ),( Bo Kun Lin ),( Gan Ji Ru ),( Zhi Biao Zhang ),( Yan Liu ),( Zhong Hu ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.2

Enteromorpha polysaccharides (EP) extracted from green algae have displayed a wide variety of biological activities. However, their high molecular weight leads to a high viscosity and low solubility, and therefore, greatly restrains their application. To solve this problem, bacteria from the surface of Enteromorpha were screened, and an Alteromonas macleodii strain B7 was found to be able to decrease the molecular weight of EP in culture media. Proteins harvested from the supernatant of the A. macleodii B7 culture were subjected to native gel electrophoresis, and a band corresponding to the Enteromorpha polysaccharide lyase (EPL) was detected by activity staining. The enzyme identity was subsequently confirmed by MALDI-TOF/TOF mass spectrometry as the putative α-amylase reported in A. macleodii ATCC 27126. The amylase gene (amySTU) from A. macleodii B7 was cloned into Escherichia coli, resulting in highlevel expression of the recombinant enzyme with EP-degrading activity. AmySTU was found to be cold-adapted; however, its optimal enzyme activity was detected at 40oC. The α-amylase was highly stable over a broad pH range (5.5-10) with the optimal pH at 7.5-8.0. The highest enzyme activity was detected when NaCl concentration was 2%, which dropped by 50% when the NaCl concentration was increased to 16%, showing an excellent nature of halotolerance. Furthermore, the amylase activity was not significantly affected by tested surfactants or the presence of some organic solvents. Therefore, the A. macleodii strain B7 and its α-amylase can be useful in lowering EP molecular weight and in starch processing.

Comparative transcriptome analysis of wing discs from Bombyx mori and Bombyx mandarina

Feng Yongjie,Kumar Dhiraj,Hu Xiaolong,Zhang Yiling,Zhu Min,Xue Renyu,Cao Guangli,Gong Chengliang 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.2

The insect wing is developed from the wing imaginal disc which is designed from the embryonic ectoderm. To get insight into gene expression profiles in wing discs of Bombyx mori during metamorphosis, we compared the gene expression in the wing between B. mori and B. mandarina moth through RNA-seq. Out of total valid reads identified from the 5th day of 5th instar larvae of silkworm (L5), 7th day of pupae (P7), 1st day of moth (M1) and 1st day of wild silkworm moth (WM1), 20,092,004, 29,251,647, 24,654,695 and 19,753,089 reads were mapped to the mRNA reference sequences of silkworm, respectively. 9229, 7048, 9268 and 6701 differentially expressed genes (DEGs) were respectively recorded in P7 vs L5, M1 vs P7, M1 vs L5 and WM1 vs M1. Further, the peroxisome, ribosome, endocytosis and oxidative phosphorylation pathways were significantly regulated in the metamorphosis of the silkworm. Our study identified 16 orthologous genes with a positive selection from M1, which might be subjected to artificial selection in the domestication of B. mori and would play vital roles in the flight of B. mandarina.