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共培养大肠杆菌和谷氨酸棒杆菌合成圣草酚研究

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陕西科技大学学报 2025年第1期43卷 52-57页

作者：查健赵停兰刘婧怡时夫龙吕宝龙田斌吴瑕陕西科技大学食品科学与工程学院陕西西安710021 宝鸡阜丰生物科技有限公司陕西宝鸡722405

微生物共培养技术在生物制造中应用广泛,尤其在天然产物的微生物合成中发挥重要作用.植物天然产物圣草酚具有抗菌、抗氧化等多种药理作用,在医药、食品等领域具有良好应用前景.为利用葡萄糖这一廉价碳源从头合成圣草酚,运用微生物共培... 详细信息

微生物共培养技术在生物制造中应用广泛,尤其在天然产物的微生物合成中发挥重要作用.植物天然产物圣草酚具有抗菌、抗氧化等多种药理作用,在医药、食品等领域具有良好应用前景.为利用葡萄糖这一廉价碳源从头合成圣草酚,运用微生物共培养技术,构建了大肠杆菌BAK101菌株与谷氨酸棒杆菌NE1菌株的共培养发酵体系,其中BAK101可将葡萄糖转化为L-酪氨酸,NE1可将L-酪氨酸转化为圣草酚.通过系统优化,采用补料分批发酵结合分段式共培养方式,利用2%的葡萄糖经过100 h发酵,在摇瓶中实现了4.72 mg/L圣草酚的从头合成.本研究为黄酮类化合物的微生物共培养合成奠定了基础,也为复杂天然产物在微生物中的从头合成提供了参考.

关键词：共培养圣草酚 L-酪氨酸大肠杆菌谷氨酸棒杆菌

Identifying crack initiation stress threshold in brittle rocks using axial strain stiffness characteristics

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Journal of Mountain Science 2018年第6期15卷 1371-1382页

作者： GAO Mei-ben LI tian-bin MENG Lu-bo MA Chun-chi XING Hui-lin state key laboratory of geohazard prevention and geoenvironment protection chengdu university of technologyChengdu 610059China college of environment and civil engineering chengdu university of technologyChengdu 610059China centre for geoscience computing school of earth sciencesthe university of queenslandSt Lucia.QLD 4072Australia

As an estimate for the in-situ spalling strength around massive underground excavations to moderately jointed brittle rocks, crack initiation stress marks the initiation of rock micro fracturing. It is crucial to accurately identify crack initiation stress level by proper method. In this study, confined compression tests of sandstone samples are used to examine the validity/applicability of proposed axial strain stiffness method. The results show that by highlighting the minuscule changes in stress-strain curve, the axial strain stiffness curve provided further insight into rock failure process and revealed five stages:(a) irregular fluctuation,(b) nearly horizontal regular fluctuation,(c) irregular fluctuation gradually decreasing to zero,(d) extreme fluctuation, and(e) near zero, which mainly correspond to five stages of stress–strain curve. The ratio of crack-initiation stress to peak strength determined using this approach is 0.44–0.51, similar to the ranges previously reported by other researchers. In this method, the key is to accurately detect the end point of the stage(b), "nearly horizontal regular fluctuation" characterized by a sudden change in axial strain stiffness curve, and the sudden change signifies crack initiation in rock sample. Finally, the research indicates that the axial strain stiffness curve can provide a mean to identify the crack-initiation stress thresholds in brittle rocks.

关键词： Brittle rock fracture Rock failure Sandstone Crack initiation stress Axial strain-stiffness Triaxial test

Progressive Modelling of the Gravity-induced Landslide Using the Local Dynamic Strength Reduction Method

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Journal of Mountain Science 2013年第4期10卷 532-540页

作者： CHEN Guo-qing HUANG Run-qiu XU Qiang LI tian-bin ZHU Ming-lei State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology

The failure of slope is a progressive process, and the whole sliding surface is caused by the gradual softening of soil strength of the potential sliding surface. From this viewpoint, a local dynamic strength reduction method is proposed to capture the progressive failure of slope. This method can calculate the warning deformation of landslide in this study. Only strength parameters of the yielded zone of landslide will be reduced by using the method. Through continuous local reduction of the strength parameters of the yielded zone, the potential sliding surface developed gradually and evolved to breakthrough finally. The result shows that the proposed method can simulate the progressive failure of slope truly. The yielded zone and deformation of landslide obtained by the method are smaller than those of overall strength reduction method. The warning deformation of landslide can be obtained by using the local dynamic strength reduction method which is based on the softening characteristics of the sliding surface.

关键词： Landslide Local dynamic reduction Warning deformation Strength softening Progressive failure

Application of ultrasonic in strength measurement of similar materials of limestone

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Journal of Central South University of Technology 2005年第z1期12卷 157-161页

作者： LIU Tie-xiong PENG Zhen-bin HAN Jin-tian School of Geoscience and Environmental Engineering Central South University Changsha 410083 China Guangdong Provincial Academy of Building Research Guangzhou 510500 China School of Geoscience and Environmental Engineering Central South University Changsha 410083 China Guangdong Provincial Academy of Building Research Guangzhou 510500 China

Similar materials such as cement, gypsum and sand are options for simulating limestone characteristic.A series of reasonable proportions are chosen to do similar experiments of Karst roof based on the proportions testing of small samples indoors. Applying on ultrasonic, the velocities of transverse wave and vertical wave of similar samples have been inspected with the sound wave instrument. Dynamic modulus of elasticity and Poisson's ratio of the samples have been educed. According to the testing data, the relationship between the transverse wave and vertical wave velocity, compressive strength and anti-bend strength are analyzed. It has been proved that the vertical wave velocity is better for reflecting compressive strength and anti-bend strength of similar materials than the transverse wave velocity. The vertical wave velocity increases with the strengthand dynamic modulus of elasticity.

关键词： ultrasonic similar materials similar theory modulus of elasticity Poisson's ratio

基于第一性原理和热力学计算的TiAl-Nb金属间化合物稳定性和相关系研究

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原子与分子物理学报 2025年第5期42卷 151-162页

作者：汪文洋徐勇田彬甘信柱王志刚梁永锋林均品山东建筑大学材料科学与工程学院济南250101 北京科技大学新金属材料国家重点实验室北京100083

采用基于广义梯度近似密度泛函理论的第一性原理计算和相图计算方法,研究了TiAl-Nb合金中γ、α_(2)、O_(2)和ωo相的热力学和力学性质以及相转变关系.研究表明,第一性原理计算得到的化合物相的参数是准确的,且分析结果与相图计算结果... 详细信息

采用基于广义梯度近似密度泛函理论的第一性原理计算和相图计算方法,研究了TiAl-Nb合金中γ、α_(2)、O_(2)和ωo相的热力学和力学性质以及相转变关系.研究表明,第一性原理计算得到的化合物相的参数是准确的,且分析结果与相图计算结果相一致.四个化合物相都是能够稳定存在的相.通过热力学和力学性质的分析,发现α_(2)相更容易转变为O_(2)相,并且在一定条件下可以通过相变反应生成ωo相.而γ相更容易转变为ωo相,但无法生成O_(2)相.

关键词： TiAl合金第一性原理相图声子谱及态密度热力学性质

Effect of type 2 diabetic mellitus in the prognosis of acute-onchronic liver failure patients in China

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World Journal of Gastroenterology 2021年第23期27卷 3372-3385页

作者： Rui-Min Lai tian-bin Chen Yu-Hai Hu Gui Wu Qi Zheng Department of Hepatology Hepatology Research InstituteThe First Affiliated HospitalFujian Medical UniversityFuzhou 350005Fujian ProvinceChina Department of Laboratory Medicine The First Affiliated HospitalFujian Medical UniversityFuzhou 350005Fujian ProvinceChina Department of Orthopedics The First Affiliated HospitalFujian Medical UniversityFuzhou 350005Fujian ProvinceChina

BACKGROUND Acute-on-chronic liver failure(ACLF)patients have a high short-term mortality rate,and the severity evaluation of ACLF is necessary for ***,it was meaningful to evaluate the association between type 2 diabetic mellitus(DM)and ACLF and further explore the feasibility of using DM as a prognostic indicator in ACLF *** association between type 2 DM and the prognosis of patients with severe liver disease remains *** To examine the effect of type 2 DM on the prognosis of patients with *** Clinical data from 222 ACLF patients were collected and *** patients were categorized into two groups depending on whether they had DM or not,and the clinical data of ACLF patients were measured within 48 h after *** of ACLF were documented during treatment,such as hepatic encephalopathy,hepatorenal syndrome,acute upper gastrointestinal hemorrhage,and spontaneous peritonitis(SBP).Values of laboratory parameters,complication rates,and hospital mortality rates were compared between two *** Among 222 ACLF patients,38 cases were categorized into DM groups,the mean age was 56.32 years and 73.68%were *** prognosis of ACLF patients was significantly correlated with DM in univariate[hazard ratio(HR)=2.4,95%confidence interval(CI)=1.5-3.7,P<0.001]and multivariable analysis(HR=3.17,95%CI=1.82-5.523,P<0.001).The incident of SBP(34.21%vs 13.59%,P=0.038)and other infections like lung,urinary,blood,and cholecyst(44.74%vs 28.26%,P=0.046)were higher in DM patients than non-DM *** addition,the ACLF patients with DM tended to have a high mortality rate(P<0.001).Cumulative survival time was also significantly shorter in the ACLF patients with DM than *** A significant association between DM and the prognosis of ACLF patients was found in *** ACLF patients with DM had higher incidence of hospital mortality and infection than those without DM.

关键词： Acute-on-chronic liver failure Diabetic mellitus Prognosis Infection Type 2 diabetic mellitus

Reconstruction of Probability Density Function for Gamma Distribution

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Journal of Donghua University(English Edition) 2020年第4期37卷 327-333页

作者： FAN Jinwei LI Zhongsheng tian bin Beijing Key Laboratory of Advanced Manufacturing Technology Beijing University of TechnologyBeijing 100124China Neijiang Jinhong Crankshaft Co. Ltd.Neijiang 641000China

The probability distributions of small sample data are difficult to determine,while a large proportion of samples occur in the early failure period,so it is particularly important to make full use of these data in the statistical *** on gamma distribution,four methods of probability density function(PDF)reconstruction with early failure data are proposed,and then the mean time between failures(MTBF)evaluation expressions are concluded from the reconstructed *** theory analysis and an example show that method 2 is the best evaluation method in dealing with early-failure-small-sample *** reconstruction methods of PDF also have certain guiding significance for other distribution types.

关键词： small sample probability density function(PDF) gamma distribution early failure mean time between failures(MTBF)

Physiological,Biochemical and Molecular Responses of Barley Seedlings to Aluminum Stress

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Phyton-International Journal of Experimental Botany 2019年第3期88卷 253-260页

作者： Xiaoqin Zhang Tao Tong bin tian Yunxia Fang Jiangjie Pan Junjun Zheng Dawei Xue College of Life and Environmental Sciences Hangzhou Normal UniversityHangzhou310036China

Barley(Hordeum vulgare L.)is one of the most Aluminum(Al)sensitive cereal *** this study,the physiological,biochemical,and molecular response of barley seedlings to Al treatment was examined to gain insight into Al response and tolerance *** results showed that superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)activity were inhibited to different degrees following Al *** MDA content also significantly increased with increasing Al *** results indicated significant differences between Al treatments and controls in terms of SRAP profile,and the genomic template stability(GTS)decreased with increasing Al concentration and *** integrative results help to elucidate the underlying mechanisms that the barley response to Al toxicity.

关键词： Barley Al stress Antioxidant enzymes SRAP(Sequence-related amplified polymorphism) GTS(Estimation of genomic template stability)

Cooperation of PprI and DrRRA in response to extreme ionizing radiation in Deinococcus radiodurans

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Chinese Science Bulletin 2012年第1期57卷 98-104页

作者： WANG LiangYan YIN LongFei XU GuangZhi LI MingFeng ZHANG Hui tian bin HUA YueJin Key Laboratory of Ministry of Agriculture for Nuclear-Agricultural Sciences Institute of Nuclear-Agricultural SciencesZhejiang UniversityHangzhou 310029China Institute of Ecology Taizhou UniversityLinhai 317000China

Deinococcus radiodurans possesses extreme resistance to ionizing radiation,and has been engineered for the remediation of toxic components in radioactive *** have previously shown that PprI(also named IrrE)and DrRRA are essential for the DNA protection and repair pathways that respond to ionizing radiation stress in this ***,we investigated the combined roles of PprI and DrRRA in resistance to gamma radiation(800 Gy).The double mutant,△drRRA△pprI,was more sensitive to gamma rays than either△drRRA or△pprI single mutants,and exhibited an elevated level of intracellular protein carbonylation,an extended delay in genome reconstitution and reduced transcriptional levels of certain DNA protection and repair proteins,such as kat,sod,recA and ***,the induction of DrRRA by ionizing radiation was partially inhibited by the deletion of pprI. Taken together,these results suggest that DrRRA and PprI might have collaborative roles in the response of *** to extreme ionizing radiation.

关键词：电离辐射诱导耐辐射球菌公共政策研究所合作超氧化物歧化酶伽玛射线转录水平