Progressive Collapse Mechanism Analysis of Concrete-Filled Square Steel Tubular Column to Steel Beam Joint with Bolted–Welded Hybrid Connection

Wang Jing-Xuan,Yang Yong,Xian Wei,Li Qiu-Ying 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.5

When vertical load-bearing members of building structures are subjected to accidental loadings, such as an earthquake, fi re or explosion, the remaining structure chiefl y relies on the beam mechanism and catenary mechanism of the steel beam as the main resistance capacity, to prevent local or large-scale progressive collapse. This paper presents a three-dimensional fi nite element model of concrete-fi lled square steel tubular (CFST) column to steel beam joint with bolted–welded hybrid connection in a middle-column-removal scenario using ABAQUS software. The multi-scale modeling method was employed to calculate the collapse resistance and mechanism under vertical load. The vertical displacement and bearing capacity curve of the middle failure column was calculated and analyzed. The collapse mechanism and bearing capacity contribution of the steel beam tying in diff erent directions are also discussed. Results indicate that the failure mechanism of the process includes the beam mechanism, the translation mechanism, the catenary mechanism and the failure stage. After the short-span steel beam had been destroyed, the long-span steel beam continued to provide collapse resistance capacity. To improve progressive collapse resistance, the CFST column to steel beam joint with welded haunch is proposed in this paper. Comparing the anti-collapse bearing capacity and failure characteristics of the joint with the welded haunch and common joint indicates that the anti-collapse capacity of the joint with welded haunch can be improved, and the research results can be referenced for engineering progressive collapse design.

중국 수출통제법 내용분석과 대응방안

왕정정(Jing-Jing Wang),주선(Xuan Zhou),최창환(Chang-Hwan Choi) 한국통상정보학회 2020 통상정보연구 Vol.22 No.4

본 연구는 2020년 12월 발효될 ｢중화인민공화국 수출통제법｣에 대해 초안과 달라진 점과 기본적 입법 취지를 파악하는 한편, GATT 제XXI조(예외조항), 미국 무역확장법 제232조 조치와 차이점 및 우리 기업에 대한 시사점을 제시하였다. 수출통제법 연구결과 제9조 수출통제리스트, 제12조 Catch all 의무조항, 13조 허가기준에 국가안전과 이익 등을 근거로 수출을 통제할 수 있으나, 국가안전과 이익의 개념이 모호할 뿐만 아니라 GATT/WTO 안보 예외 사항에 해당하여 중국이 이 조항을 근거로 자의적으로 수출통제를 할 위험성이 매우 높다고 할 것이다. 수출통제법 발효로 인한 수출통제 대상과 범위, 처벌 수위가 높아질 것으로 예상되며, 이에 따라 중국진출 우리 기업들의 연관된 제품 수출시 동 법률을 자세히 사전 검토할 필요가 있으며, 수입하는 우리 기업들도 수출통제 대상이 되지 않도록 품목, 대상, 최종 사용자 등에 관한 철저한 연구가 선행되어야 할 것이다. This study examines the differences from the draft and the final version of the “Export Control Law of the People s Republic of China”, which will take effect in December 2020, while comparing the differences in Article XXI of GATT, Section 232 of the U.S. Trade Expansion Act, and its implications for Korean businesses. As a result of the study of the Export Control Act, exports can be controlled based on national safety and interests in accordance with Article 9 Export Control List, Article 12 Catch All obligations clause, and Article 13 Permit Standards, but the concept of national safety and interests is ambiguous. In addition, it would be said that there is a very high risk that China will arbitrarily control exports based on this provision as it falls under the GATT/WTO security exception. It is expected that export control targets, scope, and penalties will increase due to the entry into force of the Export Control Act. Accordingly, it is necessary to carefully review the law when exporting related products by Korean companies entering China. Thorough research on items, targets, and end users should be preceded so that they do not become targets.

Heterologous expression of two Physcomitrella patens group 3 late embryogenesis abundant protein (LEA3) genes confers salinity tolerance in arabidopsis

Jing Du,Lei Wang,Xiaochen Zhang,Xuan Xiao,Fang Wang,Pingliang Lin,Fang Bao,Yong Hu,Yi-Kun He 한국식물학회 2016 Journal of Plant Biology Vol.59 No.2

Salinity stress is a major limiting factor in agriculture and adversely affecting the whole plant. As a halophyte, the moss Physcomitrella patens, has been suggested to be an ideal model plant to study salinity tolerance and adaption. Two abiotic stress-responsive Group 3 Late Embryogenesis Abundant protein genes had been identified in P. patens and named as PpLEA3-1 and PpLEA3-2, respectively. Functions of these two genes were analyzed by heterologous expressions in Arabidopsis, driven either by their native P. patens promoters or by the 35S CaMV constitutive promoter. Phenotype analysis revealed that pLEA3::LEA3, pLEA3::LEA3::GFP and 35S::LEA3::GFP transgenic lines had stronger salinity resistance than that in the wild type and empty-vector control. Further analysis showed that the contents of proline and soluble sugar were increased and the malondialdehyde (MDA) were repressed in these transgenic plants after exposure to salinity stress. Our observations indicate that these two Group 3 PpLEA genes played a role in the adaption to salinity stress.

Decorin: a potential therapeutic candidate for ligamentum flavum hypertrophy by antagonizing TGF-β1

Wang Shanxi,Qu Yunkun,Fang Xuan,Ding Qing,Zhao Hongqi,Yu Xiaojun,Xu Tao,Lu Rui,Jing Shaoze,Liu Chaoxu,Wu Hua,Liu Yang 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Ligamentum flavum hypertrophy (LFH) is the main physiological and pathological mechanism of lumbar spinal canal stenosis (LSCS). The specific mechanism for LFH has not been completely clarified. In this study, bioinformatic analysis, human ligamentum flavum (LF) tissues collection and analysis, and in vitro and in vivo experiments were conducted to explore the effect of decorin (DCN) on LFH pathogenesis. Here, we found that TGF-β1, collagen I, collagen III, α-SMA and fibronectin were significantly upregulated in hypertrophic LF samples. The DCN protein expression in hypertrophic LF samples was higher than that in non-LFH samples, but the difference was not significant. DCN inhibited the expression of TGF-β1-induced fibrosis-associated proteins in human LF cells, including collagen I, collagen III, α-SMA, and fibronectin. ELISAs showed that TGF-β1 can upregulate PINP and PIIINP in the cell supernatant, and this effect was inhibited after DCN administration. Mechanistic studies revealed that DCN suppressed TGF-β1-induced fibrosis by blocking the TGF-β1/SMAD3 signaling pathway. In addition, DCN ameliorated mechanical stress-induced LFH in vivo. In summary, our findings indicated that DCN ameliorated mechanical stress-induced LFH by antagonizing the TGF-β1/SMAD3 signaling pathway in vitro and in vivo. These findings imply that DCN is a potential therapeutic candidate for ligamentum flavum hypertrophy.

Molecular Characterization of Enterocytozoon bieneusi in Domestic Rabbits (Oryctolagus cuniculus) in Northeastern China

Xiao-Xuan Zhang,Jing Jiang,Ya-Nan Cai,Chun-Feng Wang,Peng Xu,Gui-Lian Yang,Quan Zhao 대한기생충학열대의학회 2016 The Korean Journal of Parasitology Vol.54 No.1

A study of 426 rabbits from 3 cities in Jilin province (Changchun City and Jilin City) and Liaoning province (Shenyang City) was conducted between May and June 2015. The overall prevalence of E. bieneusi in rabbits was 0.94% (4/426), with 0% (0/116), 1.72% (3/174), and 0.74% (1/136) in Jilin, Changchun, and Shenyang City, respectively. Only 3 farms (farm 1 and farm 3 in Changchun City, farm 8 in Shenyang City) were PCR-positive for E. bieneusi. Moreover, rabbits of more than 6 months (1.72%) had the highest E. bieneusi prevalence, followed by rabbits of 4-6 months (1.26%), 2-3 months (0.58%), and less than 1 month (0%). Analysis of ITS gene of E. bieneusi suggested that all 4 E. bieneusi isolates were genotype D, and were classified as group 1a. The present results first demonstrated the existence of zoonotic E. bieneusi in domestic rabbits in China. Effective control measures should be implemented to prevent E. bieneusi infection in domestic rabbits, other animals, and humans.

Resveratrol enhances the functionality and improves the regeneration of mesenchymal stem cell aggregates

Yi-Jing Wang,Pan Zhao,Bing-Dong Sui,Nu Liu,Cheng-Hu Hu,Ji Chen,Chen-Xi Zheng,An-Qi Liu,Kun Xuan,Ya-Ping Pan,Yan Jin 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Mesenchymal stem cell (MSC)-based regeneration, specifically cell aggregate or cell sheet engineering, is a promising approach for tissue reconstruction. Considering the advantages of ease of harvest and lack of immune rejection, the application of autologous MSCs (i.e., patients’ own MSCs) in regenerative medicine has developed considerable interest. However, the impaired cell viability and regenerative potential following MSCs impacted by disease remain a major challenge. Resveratrol (RSV) exhibits reliable and extensive rejuvenative activities that have received increasing clinical attention. Here, we uncovered that resveratrol enhances the functionality and improves the regeneration of mesenchymal stem cell aggregates. Periodontal ligament MSCs (PDLSCs) from normal control subjects (N-PDLSCs) and periodontitis patients (P-PDLSCs) were investigated. Compared to N-PDLSCs, P-PDLSCs were less capable of forming cell aggregates, and P-PDLSC aggregates showed impaired osteogenesis and regeneration. These functional declines could be mimicked in N-PDLSCs by tumor necrosis factor alpha (TNF-α) treatment. Notably, a TNF-α-induced functional decline in N-PDLSC aggregates was rescued by RSV application. More importantly, in both N-PDLSCs and P-PDLSCs, RSV promoted cell aggregate formation and improved their osteogenic potential. Furthermore, as proven ectopically in vivo, the tissue regenerative capability of P-PDLSC aggregates was also enhanced after RSV treatment during aggregate formation in vitro. Finally, in a rat in situ regeneration model, we successfully applied both N-PDLSC aggregates and P-PDLSC aggregates to repair periodontal defects upon long-term functional improvements by RSV preconditioning. Together, our data unravel a novel methodology for using pharmacology (i.e., RSV)-based cell aggregate engineering to improve the functionality and facilitate the regeneration of MSCs from both healthy and inflammatory microenvironments, shedding light on improving the application of autologous MSC-mediated regenerative medicine.

Molecular dynamics study of H4TTP crystal morphology

Chen Jing,Li Jun,Li Yongxiang,Liu Qiao'e,Zhang Xuan,Ruan Jian,Wang Xiaojun,Liu Wendong,Kim Chan Kyung 대한화학회 2022 Bulletin of the Korean Chemical Society Vol.43 No.7

To understand the role of dimethyl sulfoxide (DMSO) on the crystal growth morphology of 2,3,5,6-tetra(1H-tetrazol-5-yl)pyrazine (H4TTP), the vacuum morphology of H4TTP crystal was predicted by the Bravais–Friedel–Donnay–Harker (BFDH) and the attachment energy (AE) models. The growth morphology of H4TTP in DMSO solvent was predicted using a modified AE model. The results show that the main growth surfaces of H4TTP in vacuum are (1 0 0), (0 0 2), (0 1 1), and (1 1 0) surfaces. Among them, (1 0 0) surface is the most important growth surface. (0 0 2) surface is the roughest crystal surface, while (1 1 0) surface is the flattest. (1 1 0) surface grows rapidly, and (1 0 0) surface has the greatest morphological importance. The analysis of radial distribution function shows that (1 0 0) surface has the strongest hydrogen bonding interactions in the interface between H4TTP and DMSO solvent.

Metabolic engineering of erythritol production from glycerol by Yarrowia lipolytica

Ya-Ting Wang,Ling-Xuan Zhao,Liu-Jing Wei,Jun Chen,Zhijie Liu,Feng Liu,Qiang Hua 한국생물공학회 2024 Biotechnology and Bioprocess Engineering Vol.29 No.1

Erythritol as a four-carbon polyol has been widely used in food, pharmaceutical and daily chemical industries with characteristics of low caloric value and high chemical stability. Here, a system metabolic engineering strategy was used to increase the yield of erythritol from glycerol in Yarrowia lipolytica by enhancing the substrate transformation and restricting the by-product synthesis. Specifi cally, we determined that over-expression of a newly identifi ed erythrose reductase YPR1 was able to improve the erythritol production as same as the well-known erythrose reductase ER27. Instead of its up-regulation, knockout of erythrose reductase ER10 was eff ective to improve erythritol synthesis. Moreover, both over-expression of YPR1 and deletion of ER10 signifi cantly accelerated the glycerol utilization in response to high osmotic stress. To further decrease the by-product accumulation, a restriction and recycling strategy was implemented by knockout of mannitol dehydrogenase MDH2 and enhancement of arabitol dehydrogenase ADH1 and fructokinase HXK1. The engineered strain YL13 produced a titer of 25 g/L erythritol and less than 0.5 g/L mannitol and arabitol. By over-expression of transketolase TKL1, the fi nal strain YL14 produced 28.5 g/L erythritol and none of mannitol and arabitol. This study provides a new idea for reducing the production of by-products and improving the glycerol conversion to erythritol.

Removal of fluoroquinolone antibiotics by adsorption of dopamine-modified biochar aerogel

Hongjuan Bai,Qiaofei Zhang,Xuan Zhou,Junhang Chen,Zihan Chen,Zhuangzhuang Liu,Jun Yan,Jing Wang 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.1

As emerging contaminants used for treating various tract infections, fluoroquinolones (such as enoxacin, ofloxacin, etc.) enter water bodies via point-source discharges of wastewater treatment plants and many of them raise environmental and health concerns. Herein, a novel adsorbent, derived from a useful renewable low-cost grapefruit peel, was prepared to investigate the adsorption behavior of fluoroquinolone antibiotics (enoxacin and ofloxacin). The obtained adsorbent was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD) and thermo-gravimetric analysis and differential scanning calorimetry (TG-DSC). Further, the equilibrium sorption of the adsorption process was analyzed with isotherm models and kinetic models. Under optimal adsorption conditions, equilibrium data conformed to the Elovich model, and the kinetics of adsorption was fitted well with Redlich-Peterson model. Combined with thermodynamic analysis, electrostatic interaction, hydrogen bond, π-π stacking interaction were the possible adsorption mechanisms for both fluoroquinolone antibiotics onto the novel adsorbent. This work explored a promising adsorbent for the elimination of fluoroquinolone antibiotics in environmental remediation.

Over-expression of FaGalLDH Increases Ascorbic Acid Concentrations and Enhances Salt Stress Tolerance in Arabidopsis thaliana

Dun Wanwan,Wei Xuan,Wang Lu,Liu Jingjing,Zhao Jing,Sun Peipei,Fang Congbing,Xie Xingbin 한국식물학회 2023 Journal of Plant Biology Vol.66 No.1

The strawberry (Fragaria×ananassa) is an economically important perennial crop plant, and its fruits are rich in vitamin C (l-ascorbic acid [AsA]) and other nutrients. l-galactono-1,4-lactone dehydrogenase (GalLDH) is a key enzyme in the terminal step of AsA biosynthesis pathway in plants. Here, the GalLDH gene (FaGalLDH) was cloned from ‘Benihoppe’ strawberries. AsA content increased during fruit development and peaked at the red-ripening stage, and AsA concentrations in diferent tissues were correlated with enzyme activity and transcription level of FaGalLDH. Transient over-expression of FaGalLDH in strawberry fruit increased its overall expression and AsA production signifcantly, whereas transient RNAi of FaGalLDH decreased its expression and AsA content. Furthermore, the optimum pH and temperature for FaGalLDH activity were 8.0 and 25 °C, respectively. Ectopic expression of the FaGalLDH gene in Arabidopsis resulted in higher AsA content and enzyme activity in transgenic lines than in wild-type plants. FaGalLDH over-expression resulted in enhanced tolerance to salt stress due to reduced accumulation of malondialdehyde, H2O2, and O2 .−, as well as higher survival rates, root length, proline content, and superoxide dismutase, peroxidase, and catalase activities. These results provide useful information regarding AsA biosynthesis and salt tolerance, which may help to improve strawberry fruit quality and productivity.