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대형구조물의 구조해석 정밀도 향상을 위한 용접부 모델링 기법
다웨이진(Dawei Jin),박상후(Sang Hu Park) 대한기계학회 2012 大韓機械學會論文集A Vol.36 No.10
용접은 대형구조물을 제작할 때 영구적 접합을 위해서 많이 사용하는 공정이다. 용접부는 용융부, 부분용융부, 열영향부로 나누어지며 각각의 영역들은 다른 재료물성을 가지게 된다. 또한 용접부는 용접비드 형상에 따라 기계적 신뢰성이 많이 차이 난다. 따라서 정밀한 구조해석을 수행하기 위해서는 이러한 국부적인 용접부의 특성을 잘 고려해야 한다. 본 연구에서는 이러한 용접부의 효과적인 모델링 방법에 대하여 제안하고자 한다. 특히 하중을 받는 구조물에 잘 일어나는 세 가지 변형모드(인장모드, 굽힘모드, T-굽힘모드)에 대하여 용접부를 정밀하게 모델링하는 방법을 제안하였다. 대형구조물의 구조해석을 통하여 제안된 모델링 방법이 변형, 응력분포 등을 좀 더 정밀하게 묘사해 줌을 해석적으로 확인하였다. Welding is a well-developed, widely used process for permanently joining metal components. However, the mechanical reliability of welded parts still offers room for improvement. A weld region consists of a fusion zone, a partially melted zone, and a heat-affected zone, and each zone has different material properties. In addition, the geometrical shape of a weld bead or fillet influences the mechanical reliability. A precise structural analysis must consider how a local welded region influences the mechanical behavior of the entire structure. This study focuses on an effective modeling scheme for the weld region. It relies on experimental and numerical methods to determine the proper correlation based on experimental results and to propose a modeling scheme for welded parts.
Three-Dimensional Analysis of Chloroplast Structures Associated with Virus Infection
Jin, Xuejiao,Jiang, Zhihao,Zhang, Kun,Wang, Pengfei,Cao, Xiuling,Yue, Ning,Wang, Xueting,Zhang, Xuan,Li, Yunqin,Li, Dawei,Kang, Byung-Ho,Zhang, Yongliang American Society of Plant Biologists 2018 Plant Physiology Vol.176 No.1
<P>Three-dimensional visualization identifies structural remodeling in chloroplasts during barley stripe mosaic virus infection.</P><P>Chloroplasts are multifunctional organelles whose morphology is affected by environmental stresses. Although the three-dimensional (3D) architecture of thylakoid membranes has been reported previously, a 3D visualization of chloroplast under stress has not been explored. In this work, we used a positive-strand RNA ((+)RNA) virus, barley stripe mosaic virus (BSMV) to observe chloroplast structural changes during infection by electron tomography. The analyses revealed remodeling of the chloroplast membranes, characterized by the clustering of outer membrane-invaginated spherules in inner membrane-derived packets. Diverse morphologies of cytoplasmic invaginations (CIs) were evident with spherules at the periphery and different sized openings connecting the CIs to the cytoplasm. Immunoelectron microscopy of these viral components verified that the aberrant membrane structures were sites for BSMV replication. The BSMV αa replication protein localized at the surface of the chloroplasts and played a prominent role in eliciting chloroplast membrane rearrangements. In sum, our results have revealed the 3D structure of the chloroplasts induced by BSMV infection. These findings contribute to our understanding of chloroplast morphological changes under stress conditions and during assembly of plant (+)RNA virus replication complexes.</P>
Yuan Jin,Xiu Zhang,Tianci Feng,Mei-Sheng Li,Huifang Xiao,Shouyong Zhou,Yijiang Zhao,Jing Zhong,Dawei Yang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.115 No.-
Low ion conductivity and poor alkali resistance are still the two major obstacles for the applications ofanion exchange membranes (AEMs). In this work, the combined strategies of Carbon quantum dots(CQDs) hybrid and cross-linking modification via side-chains designing were employed to prepareorganic–inorganic hybrid AEMs. Then, the cross-linked quaternized polysulfone (CQPSf-CQDs) hybridAEMs by incorporating carbon quantum dots were successfully fabricated. After hybrid and crosslinking,the mechanical properties of CQPSf-CQDs hybrid AEMs were higher than that of the pristineone, reaching 49.4 MPa for the best one. Meanwhile, the existence of CQDs can expand the hydrophilicarea in the membrane, which is beneficial to the transport of OH. The incorporated CQDs interact weaklywith cationic groups in the side chains through hydrogen bonds. The simulation results further demonstratedthat the introduction of CQDs was beneficial to the construction of hydrophilic and hydrophobicdomains, thereby increasing OH conductivity. In addition, the prepared hybrid membranes own excellentdimensional stabilities and ion transport performances. These preliminary results give us a lot ofhopes for further experiments and optimizations for the hybrid AEMs.
Expression profiles of microRNAs in skeletal muscle of sheep by deep sequencing
Zhi-Jin Liu,Cun-Yuan Li,Xiao-Yue Li,Yang Yao,Wei Ni,Xiang-Yu Zhang,Yang Cao,Wureli Hazi,Dawei Wang,Renzhe Quan,Shuting Yu,Yuyu Wu,Songmin Niu,Yulong Cui,Yaseen Khan,Shengwei Hu 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.6
Objective: MicroRNAs are a class of endogenous small regulatory RNAs that regulate cell proliferation, differentiation and apoptosis. Recent studies on miRNAs are mainly focused on mice, human and pig. However, the studies on miRNAs in skeletal muscle of sheep are not comprehensive. Methods: RNA-seq technology was used to perform genomic analysis of miRNAs in prenatal and postnatal skeletal muscle of sheep. Targeted genes were predicted using miRanda software and miRNA-mRNA interactions were verified by quantitative real-time polymerase chain reaction. To further investigate the function of miRNAs, candidate targeted genes were enriched for analysis using gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment. Results: The results showed total of 1,086 known miRNAs and 40 new candidate miRNAs were detected in prenatal and postnatal skeletal muscle of sheep. In addition, 345 miRNAs (151 up-regulated, 94 down-regulated) were differentially expressed. Moreover, miRanda software was performed to predict targeted genes of miRNAs, resulting in a total of 2,833 predicted targets, especially miR-381 which targeted multiple muscle-related mRNAs. Furthermore, GO and KEGG pathway analysis confirmed that targeted genes of miRNAs were involved in development of skeletal muscles. Conclusion: This study supplements the miRNA database of sheep, which provides valuable information for further study of the biological function of miRNAs in sheep skeletal muscle.
A metazoan ortholog of SpoT hydrolyzes ppGpp and functions in starvation responses
Sun, Dawei,Lee, Gina,Lee, Jun Hee,Kim, Hye-Yeon,Rhee, Hyun-Woo,Park, Seung-Yeol,Kim, Kyung-Jin,Kim, Yongsung,Kim, Bo Yeon,Hong, Jong-In,Park, Chankyu,Choy, Hyon E,Kim, Jung Hoe,Jeon, Young Ho,Chung, J Nature Publishing Group, a division of Macmillan P 2010 Nature Structural and Molecular Biology Vol.17 No.10
In nutrient-starved bacteria, RelA and SpoT proteins have key roles in reducing cell growth and overcoming stresses. Here we identify functional SpoT orthologs in metazoa (named Mesh1, encoded by HDDC3 in human and Q9VAM9 in Drosophila melanogaster) and reveal their structures and functions. Like the bacterial enzyme, Mesh1 proteins contain an active site for ppGpp hydrolysis and a conserved His-Asp??box motif for Mn<SUP>2+</SUP> binding. Consistent with these structural data, Mesh1 efficiently catalyzes hydrolysis of guanosine 3??5??diphosphate (ppGpp) both in vitro and in vivo. Mesh1 also suppresses SpoT-deficient lethality and RelA-induced delayed cell growth in bacteria. Notably, deletion of Mesh1 (Q9VAM9) in Drosophila induces retarded body growth and impaired starvation resistance. Microarray analyses reveal that the amino acid??starved Mesh1 null mutant has highly downregulated DNA and protein synthesis??related genes and upregulated stress-responsible genes. These data suggest that metazoan SpoT orthologs have an evolutionarily conserved function in starvation responses.
Shu Jiang,Jing Yang,Dawei Qian,Jianming Guo,Er-xin Shang,Jin-ao Duan,Jun Xu 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.2
Ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF MS)technique combined with MetabolynxTM software was usedfor analysis of the metabolites of quercitrin by the isolatedhuman intestinal bacteria from the human feces. Four metabolitesof quercitrin were detected and tentatively identifiedbased on the characteristics of their protonated ions. Themetabolites were metabolized by four main metabolic pathwaysincluding hydroxylation, demethylation, deglycosylationand ring-cleavage. Quercitrin was metabolized to the hydroxyquercitrinand desmethylquercitrin by themajority of theisolated intestinal bacteria such as Bacteroides sp. 54, and wasdegraded to the deglycosylated product quercetin by rhamnosidaseand further ring-cleavage metabolite 3,4-dihydroxybenzoicacid by the minority of the isolated bacteria such asBacteroides sp. 45. The metabolic pathways and most of themetabolites of quercitrin were reported for the first time.
Yang Jiashu,Zhang Ming,Yang Dawei,Ma Yunfei,Tang Yuting,Xing Mengying,Li Lingyun,Chen Li,Jin Yucui,Ma Changyan 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-
Long noncoding RNAs (lncRNAs) have emerged as important regulators of osteoarthritis (OA), but the biological roles and clinical significance of most lncRNAs in OA are not fully understood. Microarray analysis was performed to identify differentially expressed lncRNAs, mRNAs, and miRNAs between normal and osteoarthritic cartilage. We found that AC008440.5 (abbreviated AC008), as well as AQP1 and ANKH, were highly expressed in osteoarthritic cartilage, whereas miR-328-3p was expressed at a low level in osteoarthritic cartilage. Functional assays showed that ectopic expression of AC008, AQP1, and ANKH significantly decreased chondrocyte viability and promoted chondrocyte apoptosis and extracellular matrix (ECM) degradation, whereas knockdown of AC008, AQP1, and ANKH resulted in the opposite effects. Moreover, miR-328-3p overexpression increased chondrocyte viability and attenuated chondrocyte apoptosis and ECM degradation, whereas inhibition of miR-328-3p resulted in the opposite effects. Bioinformatics analysis, RNA immunoprecipitation (RIP), and luciferase assays revealed that AC008 functioned as a competing endogenous RNA (ceRNA) to regulate miR-328-3p, which specifically targeted the AQP1 and ANKH genes. In addition, miR-328-3p significantly ameliorated MIA-induced OA, whereas AC008 accelerated OA progression in vivo. Furthermore, fat mass and obesity-associated (FTO)-mediated N6-methyladenosine demethylation downregulated AC008 transcription, while lower FTO expression led to upregulation of AC008 transcription in OA. In conclusion, our data reveal that AC008 plays a critical role in OA pathogenesis via the miR-328-3p‒AQP1/ANKH pathway, suggesting that AC008 may be a potential therapeutic target for OA.