The impacts of resveratrol on the retinal degeneration in a rat model of retinitis pigmentosa induced by alkylation: an in-vivo study

Weiming Yan,Yan Sun,Yutong Wang,Wangjiao Liang,Yuxin Xia,Weihua Yan,Meizhu Chen,Tao Chen,Dongliang Li 한국통합생물학회 2023 Animal cells and systems Vol.27 No.1

Upregulation of Sirtuin Type 1 (SIRT1), a nicotinamide adeninedinucleotide (NAD+)-dependentdeacetylase, has been proved to protect against ample ocular diseases, while its effect onretinitis pigmentosa (RP) has not been illustrated. The study was aimed to explore the impactsof resveratrol (RSV), a SIRT1 activator, on the photoreceptor degeneration in a rat model of RPinduced by N-methyl-N-nitrosourea (MNU), an alkylation. The rats were induced RP phenotypesvia the intraperitoneal injection of MNU. The electroretinogram was conducted and revealedthat RSV could not prevent the decline of retinal function in the RP rats. The optical coherencetomography (OCT) and the retinal histological examination were performed and showed thatthe reduced thickness of the outer nuclear layer (ONL) was not preserved by RSV intervention. The immunostaining technique was applied. Afther the MNU administration, the number of theapoptotic photoreceptors in the ONL throughout the retinasand the number of microglia cellspresent among the outer part throughout the retinas were not significantly reduced by RSV. Western blotting was also performed. The data showed that the level of SIRT1 protein wasdecreased after MNU administration, while RSV was not able to obviously alleviate thedownregulation. Our data together indicated that RSV was not able to rescue thephotoreceptor degeneration in the MNU-induced RP rats, which might be due to the MNUinducedconsumption of the NAD+.

Enzymatic Desymmetrization of 3-(4-Fluorophenyl)glutaric Anhydride through Enantioselective Alcoholysis in Organic Solvents

Weiming Liu,Yi Hu,Yang Zhang,Yan Ma,He Huang 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.3

The enzymatic desymmetrization of 3-(4-fluorophenyl)glutaric anhydride (3-FGA) was investigatedthrough lipase-catalyzed enantioselective alcoholysis inorganic solvents. An immobilized Lipase B from CandidaAntarctica (Novozym 435) was found to be an efficientbiocatalyst for the enantioselective alcoholysis of 3-FGA. Methyl tert-butyl ether (MTBE) and methanol were chosenas the suitable reaction medium and acyl acceptor,respectively. The optimum reaction temperature, molarratio of methanol to 3-FGA and 3-FGA concentration were25oC, 2:1 and 100 mM, respectively. Under these conditions,complete conversion was achieved and methyl (S)-3-(4-fluorophenyl)glutarate ((S)-MFG) was obtained in a moderateee value of 80%. Furthermore, the reaction was performedon a gram scale and the ee value of (S)-MFG was enrichedto 96% after treatment with a toluene/hexane (2/1, v/v)mixture.

Theoretical and experimental study on damage detection for beam string structure

Haoxiang He,Weiming Yan,Ailin Zhang 국제구조공학회 2013 Smart Structures and Systems, An International Jou Vol.12 No.3

Beam string structure (BSS) is introduced as a new type of hybrid prestressed string structures. The composition and mechanics features of BSS are discussed. The main principles of wavelet packet transform (WPT), principal component analysis (PCA) and support vector machine (SVM) have been reviewed. WPT is applied to the structural response signals, and feature vectors are obtained by feature extraction and PCA. The feature vectors are used for training and classification as the inputs of the support vector machine. The method is used to a single one-way arched beam string structure for damage detection. The cable prestress loss and web members damage experiment for a beam string structure is carried through. Different prestressing forces are applied on the cable to simulate cable prestress loss, the prestressing forces are calculated by the frequencies which are solved by Fourier transform or wavelet transform under impulse excitation. Test results verify this method is accurate and convenient. The damage cases of web members on the beam are tested to validate the efficiency of the method presented in this study. Wavelet packet decomposition is applied to the structural response signals under ambient vibration, feature vectors are obtained by feature extraction method. The feature vectors are used for training and classification as the inputs of the support vector machine. The structural damage position and degree can be identified and classified, and the test result is highly accurate especially combined with principle component analysis.

Theoretical and experimental study on damage detection for beam string structure

He, Haoxiang,Yan, Weiming,Zhang, Ailin Techno-Press 2013 Smart Structures and Systems, An International Jou Vol.12 No.3

Beam string structure (BSS) is introduced as a new type of hybrid prestressed string structures. The composition and mechanics features of BSS are discussed. The main principles of wavelet packet transform (WPT), principal component analysis (PCA) and support vector machine (SVM) have been reviewed. WPT is applied to the structural response signals, and feature vectors are obtained by feature extraction and PCA. The feature vectors are used for training and classification as the inputs of the support vector machine. The method is used to a single one-way arched beam string structure for damage detection. The cable prestress loss and web members damage experiment for a beam string structure is carried through. Different prestressing forces are applied on the cable to simulate cable prestress loss, the prestressing forces are calculated by the frequencies which are solved by Fourier transform or wavelet transform under impulse excitation. Test results verify this method is accurate and convenient. The damage cases of web members on the beam are tested to validate the efficiency of the method presented in this study. Wavelet packet decomposition is applied to the structural response signals under ambient vibration, feature vectors are obtained by feature extraction method. The feature vectors are used for training and classification as the inputs of the support vector machine. The structural damage position and degree can be identified and classified, and the test result is highly accurate especially combined with principle component analysis.

Theoretical tensile model and cracking performance analysis of laminated rubber bearings under tensile loading

Chen, Shicai,Wang, Tongya,Yan, Weiming,Zhang, Zhiqian,Kim, Kang-Suk Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.1

To analyze the tension performance of laminated rubber bearings under tensile loading, a theoretical tension model for analyzing the rubber bearings is proposed based on the theory of elasticity. Applying the boundary restraint condition and the assumption of incompressibility of the rubber (Poisson's ratio of the rubber material is about 0.5 according the existing research results), the stress and deformation expressions for the tensile rubber layer are derived. Based on the derived expressions, the stress distribution and deformation pattern especially for the deformation shapers of the free edges of the rubber layer are analyzed and validated with the numerical results, and the theory of cracking energy is applied to analyze the distributions of prediction cracking energy density and gradient direction. The prediction of crack initiation and crack propagation direction of the rubber layers is investigated. The analysis results show that the stress and deformation expressions can be used to simulate the stress distribution and deformation pattern of the rubber layer for laminated rubber bearings in the elastic range, and the crack energy method of predicting failure mechanism are feasible according to the experimental phenomenon.

Theoretical tensile model and cracking performance analysis of laminated rubber bearings under tensile loading

Shicai Chen,Tongya Wang,Weiming Yan,Zhiqian Zhang,김강석 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.1

To analyze the tension performance of laminated rubber bearings under tensile loading, a theoretical tension model for analyzing the rubber bearings is proposed based on the theory of elasticity. Applying the boundary restraint condition and the assumption of incompressibility of the rubber (Poisson’s ratio of the rubber material is about 0.5 according the existing research results), the stress and deformation expressions for the tensile rubber layer are derived. Based on the derived expressions, the stress distribution and deformation pattern especially for the deformation shapers of the free edges of the rubber layer are analyzed and validated with the numerical results, and the theory of cracking energy is applied to analyze the distributions of prediction cracking energy density and gradient direction. The prediction of crack initiation and crack propagation direction of the rubber layers is investigated. The analysis results show that the stressand deformation expressions can be used to simulate the stress distribution and deformation pattern of the rubber layer for laminated rubber bearings in the elastic range, and the crack energy method of predicting failure mechanism are feasible according to the experimental phenomenon.

Effect of ECAP on Mechanical Properties and Corrosion Resistance of 2024-CNTs@Ni Composite

Shuqing Zhang,Pengxiang Zhang,Weiming Xu,Hong Yan 대한금속·재료학회 2024 METALS AND MATERIALS International Vol.30 No.5

The 2024-1.5 wt%CNTs@Ni (Nickel-coated carbon nanotubes) composite were subjected to equal channel angle pressing(ECAP) deformation treatment and the microstructure, hardness distribution and tensile properties were investigated anddiscussed. The quasi-in-situ corrosion observation and COMSOL corrosion simulation were used to analyze and reveal itscorrosion behavior. The results showed that the stress and microstrain are mainly concentrated in the area near the insidecorner, and the closer the inside corner, the finer the grain size and the more dispersed the second phase and CNTs@Ni. Theaverage hardness of the ECAP-treated composite was about 136.54 HV, which was 44.41% higher than that of the as-castcomposite (94.55 HV). The properties of the ECAP-treated composite were all higher than the as-cast composite, with theyield strength, tensile strength and elongation increasing to 283.49 MPa, 399.18 MPa and 11.69%, respectively, which wereabout 44.99%, 45.97% and 344.49% higher than the as-cast composite. The electrochemical properties of the ECAP-treatedcomposite were better than the as-cast composite, with a corrosion current density of 88.319 μA∙cm2, which was 12.33%lower than that of the as-cast composite. The COMSOL simulation results indicated that the ECAP-treated composite requireda longer time when the electrolyte was immersed to the same depth.

A self-powered β-Ga2O3/CsCu2I3 heterojunction photodiode responding to deep ultraviolet irradiation

Gao Ang,Jiang Weiyu,Ma Guoliang,Liu Zeng,Li Shan,Yan Zuyong,Sun Weiming,Zhang Shaohui,Tang Weihua 한국물리학회 2022 Current Applied Physics Vol.33 No.-

In this paper, a lead-free halide perovskite CsCu2I3 film with high stability was prepared by the anti-solvent assisted crystallization method. Then, we coupled it with Ga2O3 to prepare a corresponding heterojunction deep ultraviolet (UV) photodetector. After testing, we concluded that the photodetector is sensitive to 254 nm UV light. The photodetector has good reproducibility, and has an ultra-high photo-to-dark current ratio (PDCR) of more than 105. In addition, under a bias of 10 V and an illuminated intensity of 200 μW/cm2, the responsivity (R) and specific detectivity (D*) reached 20 mA/W and 107 cm Hz1/2 W 1 (Jones), and the external quantum efficiency (EQE) is 10%. Meanwhile, the prepared photodetector could operate at zero bias, i.e., self-powered operation, along with a photocurrent of about 1 nA under illumination with UV light intensity of 200 μW/cm2.

Circular RNA CREBBP modulates cartilage degradation by activating the Smad1/5 pathway through the TGFβ2/ALK1 axis

Xu Yiyang,Mao Guping,Long Dianbo,Deng Zengfa,Xin Ruobin,Zhang Ziji,Xue Ting,Liao Weiming,Xu Jie,Kang Yan 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Osteoarthritis, characterized by articular cartilage degradation, is the leading cause of chronic disability in older adults. Studies have indicated that circular RNAs are crucial regulators of chondrocyte development and are involved in the progression of osteoarthritis. In this study, we investigated the function and mechanism of a circular RNA and its potential for osteoarthritis therapy. The expression levels of circCREBBP, screened by circular RNA sequencing during chondrogenic differentiation in adipose tissue-derived stem cells, and TGFβ2 were significantly increased in the cartilage of patients with osteoarthritis and IL-1β-induced chondrocytes. circCREBBP knockdown increased anabolism in the extracellular matrix and inhibited chondrocyte degeneration, whereas circCREBBP overexpression led to the opposite effects. Luciferase reporter assays, rescue experiments, RNA immunoprecipitation, and RNA pulldown assays confirmed that circCREBBP upregulated TGFβ2 expression by sponging miR-1208, resulting in significantly enhanced phosphorylation of Smad1/5 in chondrocytes. Moreover, intra-articular injection of adeno-associated virus-sh-circCrebbp alleviated osteoarthritis in a mouse model of destabilization of the medial meniscus. Our findings reveal a critical role for circCREBBP in the progression of osteoarthritis and provide a potential target for osteoarthritis therapy.