Two new species of Pustula (Albuginales, Oomycota) from Junggar Basin in China based on morphology and molecular data

Xu, Biao,Choi, Young Joon,Song, Jia Ge,Zhang, Shan He,Xi, Ping Gen,Shin, Hyeon Dong,De Jiang, Zi Springer-Verlag 2018 MYCOLOGICAL PROGRESS Vol.17 No.4

Modular synthesis of heparanase substrates

Peng Xu,Weichang Xu,Yuanwei Dai,Biao Yu 한국당과학회 2012 한국당과학회 학술대회 Vol.2012 No.1

Heparanase, preferentially expressed in many tumor cells, is an endoβDglucuronidase that cleaves specific sites of heparan sulfate. Elevated levels of heparanase expression correlate with tumor vasculatrity, metastatic potiential, and reduced postoperative survival of cancer patients. Consequencely, heparanase detection is considered a tool for cancer discovery. A library of 20 welldefined Tetra1 analogs were prepared in a convergent “2+2” glycosidation manner utilizing a relatively small number of protected disaccharide donors and acceptors. Among three different donors prepared for the fullprotected tetrasaccharide, trifluoroacetimidate donor was most suitable for the preservation and glycosidation reaction, and in each glycosylation, the yield was good and the major anomer was obtained. After coupling these 12 glycosydic reactions, the observation indicate that the coupling ratio is not only relating to the structure and exact nature of acceptors, but also correlated to the structure and size of donors. Key features of the approach include the use of Bz esters or PMB ethers for those hydroxyls that need sulfation, regioselective opening of the 4,6-O-benzylidene acetal for 4OBn that don’t need sulfation and 6OH that need oxidation, an anomeric TBS group for glycosyl donor synthesis, and benzyl ethers just as permanent protecting groups. The HS oligosaccharides will be employed to probe structural features of HS for cleavage of heparanase.

Experimental Investigation on Damage Behavior of Polypropylene Fiber Reinforced Concrete under Compression

Lihua Xu,Biao Li,Xiaoxiao Ding,Yin Chi,Changning Li,Biao Huang,Yuchuan Shi 한국콘크리트학회 2018 International Journal of Concrete Structures and M Vol.12 No.7

This paper presents an experimental investigation on the stress–strain behavior and the damage mechanism of polypropylene fiber reinforced concrete (PFRC) under monotonic and cyclic compression. Fifty-four specimens for different fiber volume fractions and aspect ratios were tested. Acoustic emission (AE) technique was used to monitor the damage progression. The damage mechanism of concrete was analyzed based on the AE parametric analysis. The results show that the incorporation of polypropylene fiber (PF) has a positive effect on the monotonic and cyclic behaviors of concrete, especially for the post-cracking branch. The toughness and ultimate strain are enhanced and the performance degradation in terms of elastic stiffness and strength is alleviated by the addition of PF. However, PF has little influences on the plastic strain, and the damage process of concrete is mainly driven by the envelope strain. The effect of fiber volume fraction on the cyclic behavior of concrete shows more pronounced than that of aspect ratio. In addition, it is found from AE results that the damage, closely related to AE events, has a quick evolution just after the peak stress, with the AE hits having a concentrated release. The total amount of AE hits increases with increasing fiber volume fraction due to fiber pullout and sliding, while the concrete with fiber aspect ratio of 280 reaches the largest amount. Meanwhile, as substantiated by AE, the failure of PFRC shows an obvious shear mode, with shear cracks dominating the damage progression. Finally, a damage elasto-plastic model is developed to predict the monotonic and cyclic responses of PFRC and the prediction yields a fairly close estimation with experimental results.

전시-P-123 : The Research Progress of Phenolic Foam Plastics

( Wen Biao Xu ),( Jun You Shi ) 韓國木材工學會 2013 한국목재공학회 학술발표논문집 Vol.2013 No.-

Numerical investigation of heat transfer characteristics for Subsea Xmas tree assembly

Biao Hu,Hongwu Zhu,Kuang Ding,Fangling Xu,Youjiang Zhang 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.11

This study focuses on the heat transfer characteristic of a horizontal subsea Xmas tree assembly at a high spatial resolution. Computationalfluid dynamics (steady Reynolds-averaged Navier-Stokes) in combination with Low Reynolds number modelling (LRNM) isadopted for heat transfer analysis, which has been validated against a full scale underwater gate valve heat transfer experiment with goodagreements. The characteristics of cold sea water flowing through the subsea tree, and of convection heat transfer between the subsea treeand ambient cold water are obtained. The typical “hot spots,” which have high Convection heat transfer coefficient (CHTC) and creategreat large amounts of heat loss, are numerically determined. Under the designed water depth, the effects of installation orientation, seawater velocity, and inner oil temperature on convection heat transfer are investigated as well. Such work is significant for thermal designof the subsea tree to increase structural reliability and flow assurance level.

Affinity-Purification of Fibrinogenase with High Proteolytic Activity from Agkistrodon halys (Chinese) Venom

Biao Ma,Ying Zhang,Dan Wu,Jianping Jia,Wentao Xu,Yunbo Luo 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.9

To purify and characterize the fibrinogenase with high proteolytic activity from Agkistrodon halys (Chinese) Venom. Monoclonal antibodies against fibrinogenase were prepared and a novel affinity chromatography equipped with a monoclonal antibody against fibrinogenase was developed and applied for the purification of fibrinogenases. The purified fibrinogenase was identified by fibrinolytic activity assay, and antithrombosis activity assay. HPLC chromatography and SDS-PAGE analysis demonstrated the uniformity and purity of the purified fibrinogenase. In comparison with a conventional A-50 chromatography method, affinity-purified fibrinogenase showed higher activity (3631 U mg-1 vs 501 U mg-1). In addition, the physiological activity of the fibrinogenase both in vitro and ex vivo showed the purified fibrinogenase can specifically degrade β-, γ-fibrinogen and has a high anti-thrombotic activity. In conclusion, the purified fibrinogenase by affinity column were shown to be homogeneous and showed a high and specific proteolytic activity against β-chains of fibrinogen molecules and antithrombosis activity.

Facile Synthesis of Ag/AgCl Grafted AgBi(MoO4)2 with Enhanced Photocatalytic Performance Under Visible Light

Xu Yan,Ziyang Wu,Yong Zhao,Biao Liu,Yong Zhao 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.08

Silver nanoparticles (NPs) and related semiconductors are a family of very important and widely applied photocatalysts. However, the preparation of high stability and activity of this photocatalyst is still a challenge. In this work, we report a stable Ag/AgCl/AgBi(MoO4)2 heterojunction photocatalyst fabricated via a simple in situ anion-exchange reaction followed by the photoreduction treatment. In the treatment of tetracycline (TC) wastewater under visible light, the AC-0.4 sample (prepared with 0.4 mmol KCl) exhibits the significantly improved activity (degradation ratio, DR of 71.3%) compared with the pristine AgBi(MoO4)2 (30% DR) and Ag/AgCl sample (synthesized by the photoreduction of AgCl) (37% DR) under identical experimental conditions. This activity promotion is from the fast interfacial electron transfer between the heterojunction phases of AgCl/AgBi(MoO4)2 and the SPR effect of Ag NPs. After five successive recycles, the AC-0.4 sample still maintains good stability and activity for TC degradation, which shows a great potential to be used in practical application. Through the ESR and controlled scavenged experiments, we found the · OH and · O- 2 are the major reactive intermediate species in the TC photodegradation reaction. Our work provides a new insight into the synthesis of stable and high efficient Ag-based heterojunction photocatalysts for the application of wastewater treatment.

Time-Dependent Reliability Analysis of Corroded Steel Beam

Biao Nie,Shanhua Xu,Youde Wang 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.1

The time-dependent reliability of corroded steel beam was investigated. Nine groups of specimenswere subjected to accelerate corrosion by the outdoor periodic spray test and monotonic tensile test. The surface profile of corroded steel plates and the 3D data of corrosion depth were measured by the three-dimensional non-contact surface topography instrument (PS50 3D). The probability distribution of corrosion depth and nominal yield strength of corroded steel plates were studied. Finally, a probabilistic limit state equation for corroded steel beams was established and the time-dependent failure probability and reliability index of corroded steel beams was calculated by Monte Carlo simulation method (MCS). The results of study show that the corrosion depth on steel plate surface and nominal yield strength of corroded steel plate conformed to the normal distribution. With the increase of corrosion time, the average, the standard deviation of the corrosion depth and relative yield strength increased while the mean of relative yield strength, nominal yield strength, nominal ultimate strength, the elongation decreased. The reliability index decreased rapidly with corrosion time, which shows that the reliability of steel structures under the aggressive environmental should be caused attention.

Effect of initial coating crack on the mechanical performance of surface-coated zircaloy cladding

Xu, Ze,Liu, Yulan,Wang, Biao Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.4

In this paper, the mechanical performance of cracked surface-coated Zircaloy cladding, which has different coating materials, coating thicknesses and initial crack lengths, has been investigated. By analyzing the stress field near the crack tip, the safety zone range of initial crack length has been decided. In order to determine whether the crack can propagate along the radial (r) or axial (z) directions, the energy release rate has been calculated. By comparing the energy release rate with fracture toughness of materials, we can divide the initial crack lengths into three zones: safety zone, discussion zone and danger zone. The results show that Cr is suitable coating material for the cladding with a thin coating while Fe-Cr-Al have a better fracture mechanical performance in the cladding with thick coating. The Si-coated and SiC-coated claddings are suitable for reactors with low power fuel elements. Conclusions in this paper can provide reference and guidance for the cladding design of nuclear fuel elements.

Affinity-Purification of Fibrinogenase with High Proteolytic Activity from Agkistrodon halys (Chinese) Venom

Ma, Biao,Zhan, Ying,Wu, Dan,Jia, Jianping,Xu, Wentao,Luo, Yunbo 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.9

To purify and characterize the fibrinogenase with high proteolytic activity from Agkistrodon halys (Chinese) Venom. Monoclonal antibodies against fibrinogenase were prepared and a novel affinity chromatography equipped with a monoclonal antibody against fibrinogenase was developed and applied for the purification of fibrinogenases. The purified fibrinogenase was identified by fibrinolytic activity assay, and antithrombosis activity assay. HPLC chromatography and SDS-PAGE analysis demonstrated the uniformity and purity of the purified fibrinogenase. In comparison with a conventional A-50 chromatography method, affinity-purified fibrinogenase showed higher activity ($3631\;U\;mg^{-1}$ vs $501\;U\;mg^{-1}$). In addition, the physiological activity of the fibrinogenase both in vitro and ex vivo showed the purified fibrinogenase can specifically degrade $\beta$-, $\gamma$-fibrinogen and has a high anti-thrombotic activity. In conclusion, the purified fibrinogenase by affinity column were shown to be homogeneous and showed a high and specific proteolytic activity against $\beta$-chains of fibrinogen molecules and antithrombosis activity.