• 제목/요약/키워드: Education Ministry

검색결과 2,603건 처리시간 0.026초

Effects of Marbling on Meat Quality Characteristics and Intramuscular Connective Tissue of Beef Longissimus Muscle

  • Li, Chunbao;Zhou, Guanghong;Xu, Xinglian;Zhang, Jingbo;Xu, Shuqin;Ji, Yanfeng
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권12호
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    • pp.1799-1808
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    • 2006
  • This study was designed to explore the effects of marbling on meat quality characteristics and intramuscular connective tissue of beef longissimus muscle. Chemical determinations, histological and mechanical measurements were performed on the raw and cooked meat at d 4 postmortem. The results showed that crude fat, collagen, fiber diameter and maximum transition temperature of intramuscular connective tissue increased (p<0.05) with the increase of marbling score. The cooking losses, collagen solubility, WBSF and perimysial thickness decreased (p<0.05) with the increasing marbling. WBSF correlated (p<0.05) with moisture, crude fat, collagen, cooking losses, sarcomere length and perimysial thickness. The development of marbling results in the decline in cooking losses, the avoidance of sarcomere shortening, and the disorganization of the perimysia, which accounts for the improvement of beef tenderness.

Four Butenolides are Novel Cytotoxic Compounds Isolated from the Marine-Derived Bacterium, Streptoverticillium luteoverticillatum 11014

  • Li, De-Hai;Zhu, Tian-Jiao;Liu, Hong-Bing;Fang, Yu-Chun;Gu, Qian-Qun;Zhu, Wei-Ming
    • Archives of Pharmacal Research
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    • 제29권8호
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    • pp.624-626
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    • 2006
  • Four known butenolides were isolated from the ethyl acetate extracts of the culture broth of the marine-derived bacterium, Streptoverticillium luteoverticillatum, by bioassay-guided fractionation. The structures were identified on the basis of spectral data. The absolute configuration of compound (1) was determined by CD spectrum for the first time. Compounds 1-4 showed in vitro cytotoxicity against the murine lymphoma P388 and human leukemia K562 cell lines. This is the first report on the isolation of butenolides from the marine bacterium, Streptoverticillium luteoverticillatum, and their cytotoxic activities.

Obliquely incident earthquake for soil-structure interaction in layered half space

  • Zhao, Mi;Gao, Zhidong;Wang, Litao;Du, Xiuli;Huang, Jingqi;Li, Yang
    • Earthquakes and Structures
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    • 제13권6호
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    • pp.573-588
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    • 2017
  • The earthquake input is required when the soil-structure interaction (SSI) analysis is performed by the direct finite element method. In this paper, the earthquake is considered as the obliquely incident plane body wave arising from the truncated linearly elastic layered half space. An earthquake input method is developed for the time-domain three-dimensional SSI analysis. It consists of a new site response analysis method for free field and the viscous-spring artificial boundary condition for scattered field. The proposed earthquake input method can be implemented in the process of building finite element model of commercial software. It can result in the highly accurate solution by using a relatively small SSI model. The initial condition is considered for the nonlinear SSI analysis. The Daikai subway station is analyzed as an example. The effectiveness of the proposed earthquake input method is verified. The effect of the obliquely incident earthquake is studied.

Metabolic Engineering of Saccharomyces cerevisiae to Improve Glucan Biosynthesis

  • Zhou, Xing;He, Jing;Wang, Lingling;Wang, Yang;Du, Guocheng;Kang, Zhen
    • Journal of Microbiology and Biotechnology
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    • 제29권5호
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    • pp.758-764
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    • 2019
  • ${\beta}$-Glucan is a chief structural polymer in the cell wall of yeast. ${\beta}$-Glucan has attracted intensive attention because of its wide applications in health protection and cosmetic areas. In the present study, the ${\beta}$-glucan biosynthesis pathway in S. Cerevisiae was engineered to enhance ${\beta}$-glucan accumulation. A newly identified bacterial ${\beta}-1$, 6-glucan synthase GsmA from Mycoplasma agalactiae was expressed, and increased ${\beta}$-glucan content by 43%. In addition, other pathway enzymes were investigated to direct more metabolic flux towards the building of ${\beta}$-glucan chains. We found that overexpression of Pgm2 (phosphoglucomutase) and Rho1 (a GTPase for activating glucan synthesis) significantly increased ${\beta}$-glucan accumulation. After further optimization of culture conditions, the ${\beta}$-glucan content was increased by 53.1%. This study provides a new approach to enhance ${\beta}$-glucan biosynthesis in Saccharomyces cerevisiae.

Further study on improvement on strain concentration in through-diaphragm connection

  • Qin, Ying;Zhang, Jingchen;Shi, Peng;Chen, Yifu;Xu, Yaohan;Shi, Zuozheng
    • Steel and Composite Structures
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    • 제39권2호
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    • pp.135-148
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    • 2021
  • Hollow structural section (HSS) columns have been increasingly popular due to their structural and architectural merits. However, practical difficulty lies in developing proper connections. The through-diaphragm connections are considered as suitable connection type that is widely adopted in Asian countries. However, the stress concentration occurs at the location connecting through-diaphragm and steel beam. Furthermore, the actual load path from the beam flange is not uniformly transferred to the HSS column as conventionally assumed. In this paper, tensile tests were further conducted on three additional specimens with beam flange plate to evaluate the load versus displacement response. The load-displacement curves, yield and ultimate capacity, ductility ratio were obtained. Furthermore, the strain development at different loading levels was discussed comprehensively. It is shown that the studied connection configuration significantly reduces the stress concentration. Meanwhile, simplified trilinear load-displacement analytical model for specimen under tensile load was presented. Good agreement was found between the theoretical and experimental results.

Microscopic damping mechanism of micro-porous metal films

  • Du, Guangyu;Tan, Zhen;Li, Zhuolong;Liu, Kun;Lin, Zeng;Ba, Yaoshuai;Ba, Dechun
    • Current Applied Physics
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    • 제18권11호
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    • pp.1388-1392
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    • 2018
  • Metal thin films are used widely to solve the vibration problem. However, damping mechanism is still not clear, which limits the further improvement of the damping properties for film and the development of multi-functional damping coating. In this paper, Damping microscopic mechanism of porous metal films was investigated at both macroscopically and microscopically mixed levels. Molecular dynamics simulation method was used to model and simulate the loading-unloading numerical experiment on the micro-pore and vacancy model to get the stress-strain curve and the microstructure diagram of different defects. And damping factor was calculated by the stress-strain curve. The results show that dislocations and new vacancies appear in the micro-pores when metal film is stretched. The energetic consumption from the motion of dislocation is the main reason for the damping properties of materials. Micro-mechanism of damping properties is discussed with the results of in-situ experiment.

Laser decontamination for radioactive contaminated metal surface: A review

  • Qian Wang;Feisen Wang;Chuang Cai;Hui Chen;Fei Ji;Chen Yong;Dasong Liao
    • Nuclear Engineering and Technology
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    • 제55권1호
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    • pp.12-24
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    • 2023
  • With the improvement of laser technology, the strategic needs of efficient and precise decontamination of various components in nuclear application units can be fulfilled by laser decontamination. The surface contaminants of nuclear facilities mainly exist both as loose contaminated layer and fixed oxide layer. The types of radionuclides and contamination layer thickness are closely related to the operation status of nuclear facilities, which have an important influence on the laser decontamination process. This study reviewed the mechanism of laser surface treatment and the influence of laser process parameters on the decontamination thickness, decontamination factor, decontamination efficiency and the distribution of aerosol particle. Although multiple studies have been performed on the mechanism of laser processing and laser decontamination process, there are few studies on the microscopic process mechanism of laser decontamination and the influence of laser decontamination on surface properties. In particular, the interaction between laser and radioactive contaminants needs more research in the future.

The differences between copper sulfate and tribasic copper chloride on growth performance, redox status, deposition in tissues of pigs, and excretion in feces

  • Zheng, Ping;Pu, Bei;Yu, Bing;He, Jun;Yu, Jie;Mao, Xiangbing;Luo, Yuheng;Luo, Junqiu;Huang, Zhiqing;Luo, Chenggui;Wang, Shaohui;Chen, Daiwen
    • Asian-Australasian Journal of Animal Sciences
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    • 제31권6호
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    • pp.873-880
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    • 2018
  • Objective: The objective of this experiment was to compare the effects of adding 130 mg/kg Cu from either copper sulfate (CS) or tribasic copper chloride (TBCC) on growth performance, mineral deposition in tissues, and the excretion in feces of pigs as well as changes in the mineral contents in tissues and feces when the supplemental Cu level was decreased from 130 mg/kg to 10 mg/kg. Methods: A total of 72 pigs ($32.6{\pm}1.2kg$) were randomly assigned to a CS diet or a TBCC diet with 6 pens per treatment. The trial lasted 102 d and included 3 phases (phase 1, 1 to 30 d; phase 2, 31 to 81 d; and phase 3, 82 to 102 d). The supplemental levels of Cu in the 2 treatments were 130 mg/kg in phase 1 and 2 and 10 mg/kg in phase 3. Results: The results showed that pigs fed the CS diet tended to have higher average daily gain than pigs fed the TBCC diet during d 1 to 81 (p<0.10). Compared with CS, TBCC increased the activities of aspartate transaminase (AST), ceruloplasmin, and superoxide dismutase in serum on d 30 (p<0.05). The TBCC decreased the Cu level in the liver on d 81 (p<0.05) and increased the Mn level in the liver on d 102 (p<0.05). The concentration of Cu in feces sharply decreased when the supplemental Cu level in diet changed from 130 mg/kg to 10 mg/kg in both diets (p<0.05). Conclusion: The result suggested that TBCC and CS had no significant difference on growth performance but TBCC had higher activities of AST and antioxidant enzymes and lower liver Cu than CS when pigs fed diets with 130 mg Cu /kg diet.

Cloning of porcine chemerin, ChemR23 and GPR1 and their involvement in regulation of lipogenesis

  • Huang, Jianfeng;Zhang, Jian;Lei, Ting;Chen, Xiaodong;Zhang, Yan;Zhou, Lulu;Yu, An;Chen, Zhilong;Zhou, Ronghua;Yang, Zaiqing
    • BMB Reports
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    • 제43권7호
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    • pp.491-498
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    • 2010
  • Chemerin is a novel adipokine which is abundant in adipose tissue to promote adipocyte differentiation and with significant relativity to BMI and insulin sensitivity. We report here the molecular characterization of porcine chemerin and its receptors ChemR23 and GPR1, as well as their transcriptional regulation during lipogenesis. Chemerin was mainly expressed in liver, intestine, kidney and adipose tissue, consistent with the expression pattern of GPR1, but not ChemR23, which was predominantly present in spleen and temperately in adipose tissue. We further investigated the lipogenesis-related transcriptional activation of $PPAR{\gamma}$ and KLF15 on chemerin and its receptors. The data showed that KLF15, but not $PPAR{\gamma}$, can up-regulate the mRNA level of chemerin, ChemR23 and GPR1, which was consistent with the results of luciferase assay that confirmed the effect of KLF15 on ChemR23 promoter. Taken together, our data provide basic molecular information for the further investigation on the function of chemerin in lipogenesis.