Stabilization of a Coupled ODE-wave System with Disturbances

Lu Lu,Yu-Long Zhang,Jun-Min Wang,Dong-Xia Zhao 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.3

This paper is devoted to stabilizing an ODE-PDE coupled system with boundary disturbance, where the PDE is chosen to be a wave equation with viscous damping. Applying the active disturbance rejection control (ADRC) technic, the unknown disturbance is estimated by the extended state observer (ESO). Assuming the absence of disturbance, the dynamic boundary connection is designed. The methods of spectral analysis and separation of operator are applied, which ensures the Riesz basis property as well as the spectrum determined growth condition. The exponential stability of the coupled system without disturbance is then concluded. Finally, combining the disturbance estimation and the dynamic boundary connection, a feedback controller designed to stabilize the coupled system, and the closed-loop system is proved to be asymptotically stable.

A Prediction Model Based on the Risk Factors Associated with Pathological Upgrading in Patients with Early-Stage Gastric Neoplasms Diagnosed by Endoscopic Forceps Biopsy

Zhao Yu Han,Zheng Yu,Sha Jie,Hua Hong Jin,Li Ke Dong,Lu Yu,Dang Yi Ni,Zhang Guo Xin 거트앤리버 소화기연관학회협의회 2023 Gut and Liver Vol.17 No.1

Background/Aims: The discrepancies between the diagnosis of preoperative endoscopic forceps biopsy (EFB) and endoscopic submucosal dissection (ESD) in patients with early gastric neoplasm (EGN) exist objectively. Among them, pathological upgrading directly influences the accuracy and appropriateness of clinical decisions. The aims of this study were to investigate the risk factors for the discrepancies, with a particular focus on pathological upgrading and to establish a prediction model for estimating the risk of pathological upgrading after EFB. Methods: We retrospectively collected the records of 978 patients who underwent ESD from December 1, 2017 to July 31, 2021 and who had a final histopathology determination of EGN. A nomogram to predict the risk of pathological upgrading was constructed after analyzing subgroup differences among the 901 lesions enrolled. Results: The ratio of pathological upgrading was 510 of 953 (53.5%). Clinical, laboratorial and endoscopic characteristics were analyzed using univariable and binary multivariable logistic regression analyses. A nomogram was constructed by including age, history of chronic atrophic gastritis, symptoms of digestive system, blood high density lipoprotein concentration, macroscopic type, pathological diagnosis of EFB, uneven surface, remarkable redness, and lesion size. The C-statistics were 0.804 (95% confidence interval, 0.774 to 0.834) and 0.748 (95% confidence interval, 0.664 to 0.832) in the training and validation set, respectively. We also built an online webserver based on the proposed nomogram for convenient clinical use. Conclusions: The clinical value of identifying the preoperative diagnosis of EGN lesions is limited when using EFB separately. We have developed a nomogram that can predict the probability of pathological upgrading with good calibration and discrimination value.

Strategies for Constructing Tissue-Engineered Fat for Soft Tissue Regeneration

Zhao Jing,Lu Feng,Dong Ziqing 한국조직공학과 재생의학회 2024 조직공학과 재생의학 Vol.21 No.3

Background: Repairing soft tissue defects caused by inflammation, tumors, and trauma remains a major challenge for surgeons. Adipose tissue engineering (ATE) provides a promising way to solve this problem. Methods: This review summarizes the current ATE strategies for soft tissue reconstruction, and introduces potential construction methods for ATE. Results: Scaffold-based and scaffold-free strategies are the two main approaches in ATE. Although several of these methods have been effective clinically, both scaffold-based and scaffold-free strategies have limitations. The third strategy is a synergistic tissue engineering strategy and combines the advantages of scaffold-based and scaffold-free strategies. Conclusion: Personalized construction, stable survival of reconstructed tissues and functional recovery of organs are future goals of building tissue-engineered fat for ATE. Background: Repairing soft tissue defects caused by inflammation, tumors, and trauma remains a major challenge for surgeons. Adipose tissue engineering (ATE) provides a promising way to solve this problem. Methods: This review summarizes the current ATE strategies for soft tissue reconstruction, and introduces potential construction methods for ATE. Results: Scaffold-based and scaffold-free strategies are the two main approaches in ATE. Although several of these methods have been effective clinically, both scaffold-based and scaffold-free strategies have limitations. The third strategy is a synergistic tissue engineering strategy and combines the advantages of scaffold-based and scaffold-free strategies. Conclusion: Personalized construction, stable survival of reconstructed tissues and functional recovery of organs are future goals of building tissue-engineered fat for ATE.

Isolation and Preliminary Identification of a Novel Microorganism Producing Aspartame from Soil Samples

Jian Dong Cui,Ya Nan Zhang,Gui Xia Zhao,Shi Ru Jia,Guo Qun Zhao,Si Zhang,Jun Lu 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.2

To develop a new method for producing aspartame (APM), a simple and efficient strategy for the isolation of certain microorganisms producing APM from soil samples was designed. A newly strain with secreting certain specific dipeptidase to directly synthesize APM from the substrates of L-aspartic acid (L-Asp) and Lphenylalanine methyl ester (L-PM) without protection for amino acid side chains was screened from soil samples. APM concentration in reaction mixture was quantified by high performance liquid chromatography (HPLC), yield reached 0.015 g/L. Examination of the general morphological characteristics and data from the sequence analysis of the rDNA-ITS gene led to identification of the isolate as a strain of fungal endophyte spp. The newly isolated strain had a high potential for application in industrial processes for APM production. In particular, this new method was low cost for synthesis of APM during the reaction due to avoiding protection for amino acid side chains and optical resolution of the mixtures. As we known it, this is first report that a newly strain with a high potential for selective synthesis of the APM was isolated from soil.

Profiles of Bacillus spp. Isolated from the Rhizosphere of Suaeda glauca and Their Potential to Promote Plant Growth and Suppress Fungal Phytopathogens

( Ping Lu ),( Ke Jiang ),( Ya-qiao Hao ),( Wan-ying Chu ),( Yu-dong Xu ),( Jia-yao Yang ),( Jia-le Chen ),( Guo-hong Zeng ),( Zhou-hang Gu ),( Hong-xin Zhao ) 한국미생물 · 생명공학회 2021 Journal of microbiology and biotechnology Vol.31 No.9

Members of the genus Bacillus are known to play an important role in promoting plant growth and protecting plants against phytopathogenic microorganisms. In this study, 21 isolates of Bacillus spp. were obtained from the root micro-ecosystem of Suaeda glauca. Analysis of the 16S rRNA genes indicated that the isolates belong to the species Bacillus amyloliquefaciens, Bacillus velezensis, Bacillus subtilis, Bacillus pumilus, Bacillus aryabhattai and Brevibacterium frigoritolerans. One of the interesting findings of this study is that the four strains B1, B5, B16 and B21 are dominant in rhizosphere soil. Based on gyrA, gyrB, and rpoB gene analyses, B1, B5, and B21 were identified as B. amyloliquefaciens and B16 was identified as B. velezensis. Estimation of antifungal activity showed that the isolate B1 had a significant inhibitory effect on Fusarium verticillioides, B5 and B16 on Colletotrichum capsici (syd.) Butl, and B21 on Rhizoctonia cerealis van der Hoeven. The four strains grew well in medium with 1-10% NaCl, a pH value of 5-8, and promoted the growth of Arabidopsis thaliana. Our results indicate that these strains may be promising agents for the biocontrol and promotion of plant growth and further study of the relevant bacteria will provide a useful reference for the development of microbial resources.

Research on Miscibility and Performances of PVA Fiber and Asphalt Mixtures

Yang Zhao,Xiao-dong Jia,Xiang-ke Zhang,Lu Li,Nai-xing Liang 한국고분자학회 2023 폴리머 Vol.47 No.1

In this research, the miscibility of polyvinyl alcohol (PVA) fiber and asphalt under high temperature was explored for improving the performances of PVA/asphalt mixture. Our research shows that the PVA fiber can maintain its properties after heating at 130 oC, which lays a foundation for the mixing of PVA fiber with asphalt. According to this, PVA fibers have been uniformly dispersed in asphalt by an extrusion mixing method at 130 oC. With the addition of PVA fiber, the viscosity, shear strength, complex modulus and rutting factor of the asphalt at high temperature. Besides, the cumulative strain and non-recoverable creep compliance of the PVA/asphalt mixture decreased with the increase of PVA content, which means the PVA/asphalt mixture had a good recovery ability at high temperature. This research provides a basis for the research on miscibility and performance of PVA/asphalt mixture.

A FKBP5 mutation is associated with Paget’s disease of bone and enhances osteoclastogenesis

Bingru Lu,Yulian Jiao,Yinchang Wang,Jing Dong,Muyun Wei,Bin Cui,Yafang Sun,Laicheng Wang,Bingchang Zhang,Zijiang Chen,Yueran Zhao 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Paget’s disease of bone (PDB) is a common metabolic bone disease that is characterized by aberrant focal bone remodeling, which is caused by excessive osteoclastic bone resorption followed by disorganized osteoblastic bone formation. Genetic factors are a critical determinant of PDB pathogenesis, and several susceptibility genes and loci have been reported, including SQSTM1, TNFSF11A, TNFRSF11B, VCP, OPTN, CSF1 and DCSTAMP. Herein, we report a case of Chinese familial PDB without mutations in known genes and identify a novel c.163G4C (p.Val55Leu) mutation in FKBP5 (encodes FK506-binding protein 51, FKBP51) associated with PDB using whole-exome sequencing. Mutant FKBP51 enhanced the Akt phosphorylation and kinase activity in cells. A study of osteoclast function using FKBP51V55L KI transgenic mice proved that osteoclast precursors from FKBP51V55L mice were hyperresponsive to RANKL, and osteoclasts derived from FKBP51V55L mice displayed more intensive bone resorbing activity than did FKBP51WT controls. The osteoclast-specific molecules tartrate-resistant acid phosphatase, osteoclast-associated receptor and transcription factor NFATC1 were increased in bone marrow-derived monocyte/ macrophage cells (BMMs) from FKBP51V55L mice during osteoclast differentiation. However, c-fos expression showed no significant difference in the wild-type and mutant groups. Akt phosphorylation in FKBP51V55L BMMs was elevated in response to RANKL. In contrast, IκB degradation, ERK phosphorylation and LC3II expression showed no difference in wild-type and mutant BMMs. Micro-CT analysis revealed an intensive trabecular bone resorption pattern in FKBP51V55L mice, and suspicious osteolytic bone lesions were noted in three-dimensional reconstruction of distal femurs from mutant mice. These results demonstrate that the mutant FKBP51V55L promotes osteoclastogenesis and function, which could subsequently participate in PDB development.

잔골재율 변화에 따른 된비빔 콘크리트의 재료분리 저항성 평가

자오양(ZHAO, YANG),여량량(Lu, LiangLiang),강병회(Kang, Byung-Hoe),조만기(Jo, Man-Ki),한동엽(Han, Dong-Yeop),한천구(Han, Cheon-Goo) 대한건축학회 2014 대한건축학회 학술발표대회 논문집 Vol.34 No.2

Annealing effect on plastic flow in nanocrystalline CoCrFeMnNi high-entropy alloy: A nanomechanical analysis

Lee, Dong-Hyun,Lee, Jung-A,Zhao, Yakai,Lu, Zhaoping,Suh, Jin-Yoo,Kim, Ju-Young,Ramamurty, Upadrasta,Kawasaki, Megumi,Langdon, Terence G.,Jang, Jae-il Elsevier 2017 ACTA MATERIALIA Vol.140 No.-

<P>The influence of annealing on the constitutive stress-strain response of nanocrystalline (nc) CoCrFeMnNi high-entropy alloy (HEA) was investigated through a series of nanoindentation experiments using five different three-sided pyramidal indenters. The nc HEA, produced by high-pressure torsion (HPT), was subjected to annealing at 450 degrees C for 1 and 10 h. Microstructural analysis using transmission electron microscopy (TEM) showed that three different nano-scale precipitates (NiMn-, FeCo-, and Co-rich phases) form in the primary single-phase matrix of nc HEA after annealing. The strain-dependent plastic flow response of nc HEA pre- and post-annealing was estimated using the indentation strain and constraint factor, revealing a significant strain softening in nc HEA, which becomes pronounced after annealing. TEM analysis of the deformed material underneath the indenter suggests that the plastic deformation aids in the dissolution of the annealing-induced intermetallic precipitates, which could be the mechanism for the pronounced softening. The dissolution mechanism was rationalized by the destabilization of precipitates during plastic deformation due to the increase in interface energy. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.</P>

Spherical nanoindentation creep behavior of nanocrystalline and coarse-grained CoCrFeMnNi high-entropy alloys

Lee, Dong-Hyun,Seok, Moo-Young,Zhao, Yakai,Choi, In-Chul,He, Junyang,Lu, Zhaoping,Suh, Jin-Yoo,Ramamurty, Upadrasta,Kawasaki, Megumi,Langdon, Terence G.,Jang, Jae-il Elsevier 2016 Acta materialia Vol.109 No.-

<P>Time-dependent plastic deformation behavior of nanocrystalline (nc) and coarse-grained (cg) CoCrFeMnNi high-entropy alloys (HEAs) was systematically explored through a series of spherical nano indentation creep experiments. High-pressure torsion (HPT) processing was performed for achieving nc microstructure in the HEA, leading to a reduction in grain size from similar to 46 pm for the as-cast state to similar to 33 nm at the edge of the HPT disk after 2 turns. Indentation creep tests revealed that creep deformation indeed occurs in both cg and nc HEAs even at room temperature and it is more pronounced with an increase in strain. The creep stress exponent, n, was estimated as similar to 3 for cg HEA and similar to 1 for nc HEA and the predominant creep mechanisms were investigated in terms of the values of n and the activation volumes. Through theoretical calculations and comparison of the creep strain rates for nc HEA and a conventional face-centered-cubic nc metal (Ni), the influence of sluggish diffusion on the creep resistance of nc HEA was analyzed. In addition, sharp indentation creep tests were performed for comparison purposes and the results confirmed that the use of a spherical indenter is clearly more appropriate for investigating the creep behavior of this HEA. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.</P>