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Microstructure and magnetostrictive properties of Tb doped Fe–Ga bulk alloys prepared by melt quenching

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Rare Metals 2014年第3期33卷 309-312页

作者： shu-xin Zhang Wei Wu xiao-xi Zhu jing-Hua Liu Cheng-Bao Jiang School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics

The microstructure and magnetostrictive properties were investigated in the Tb doped Fe83Ga17-xTbx（x = 0.05, 0.10, 0.20, 0.30, 0.40, 0.50） bulk rods prepared by melt rapidly quenching. The partial solid solubility of Tb in the Fe-Ga matrix was preliminary detected by the lattice parameters and SEM observation. The matrix keeps A2 structure and the second phase appears surround the grain boundary as x C 0.1. h100 i preferred orientation is also observed for x = 0.1 sample along the axis of the quenched rod. The saturation magnetostriction first increases and maximum value reaches at x = 0.1, and then decreases with Tb addition increasing. The initial increase of the magnetostriction should be associated with the partial solution of Tb in the matrix, the maximum value at x = 0.1 should be attributed to the h100 i preferred orientation, and the decrease of the magnetostriction is correlated with the appearance of the second phase along the grain boundary.

关键词： Fe-Ga alloys Magnetostriction Microstructure Melt quenching

呋虫胺和唑虫酰胺在茶叶加工过程中的残留特征及膳食风险评估

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食品科学 2025年第1期46卷 192-199页

作者：李春勇吕莹金静王霞秦曙山西农业大学山西功能农产品检验检测中心山西太原030031

为明确呋虫胺和唑虫酰胺微乳剂在茶叶种植、烘干、浸泡过程中的残留特征,在山东、浙江等10地开展规范农药登记残留田间试验,并进行加工因子校正膳食风险评估模型比较研究。样品经体积分数5%甲酸-乙腈提取、盐析分层、分散固相萃取净化后... 详细信息

为明确呋虫胺和唑虫酰胺微乳剂在茶叶种植、烘干、浸泡过程中的残留特征,在山东、浙江等10地开展规范农药登记残留田间试验,并进行加工因子校正膳食风险评估模型比较研究。样品经体积分数5%甲酸-乙腈提取、盐析分层、分散固相萃取净化后,经超高效液相色谱-串联质谱法检测,外标法定量。结果表明:在0.005~0.500μg/mL范围内,呋虫胺及其代谢物、唑虫酰胺质量浓度与其响应峰面积呈良好线性关系(R^(2)>0.99),在0.05、1.00、20.00、50.00 mg/kg(茶鲜叶、茶干叶),0.05、0.10、5.00 mg/kg(茶汤)添加水平下,呋虫胺及其代谢物1-甲基-3-[(3-四氢呋喃)甲基]脲、1-甲基-3-[(3-四氢呋喃)甲基]二氢胍盐的平均加标回收率为74%~103%,相对标准偏差为1%~9%;唑虫酰胺的平均加标回收率为75%~95%,相对标准偏差为1%~6%,方法定量限均为0.05 mg/kg;20%呋虫胺·唑虫酰胺微乳剂按推荐剂量施药后,呋虫胺(含代谢物)在茶鲜叶中的规范残留试验中值(supervised trials median residue,STMR)经烘干因子校正后与茶干叶中STMR相应的国家估算每日摄入量(national estimated daily intake,NEDI)均为4.08 mg,占每日允许摄入量(allowable daily intake,ADI)的32.4%;唑虫酰胺在茶鲜叶中的STMR经烘干因子校正后的NEDI为0.17581 mg,占ADI的46.5%,茶干叶中STMR对应的NEDI为0.18925 mg,占ADI的50.1%,呋虫胺和唑虫酰胺在不同评估模型下获得的长期膳食暴露风险均低于100%;呋虫胺(含代谢物)经加工因子校正后的国际短期膳食摄入量(international estimation of short-term dietary intake,IESTI)与校正前处于同一风险水平,低于急性参考剂量(acute reference dose,ARfD)(1 mg/kg);唑虫酰胺的IESTI为3.46×10^(-4) mg/kg(采收间隔7 d),低于ARf D(0.01 mg/kg),本研究方法在茶汤中未检测到唑虫酰胺残留,故未得到浸泡因子及相应的IESTI。综上,按推荐剂量在茶树上使用20%呋虫胺·唑虫酰胺微乳剂是安全的,最终残留量对应的长期及急性膳食摄入风险均在可接受范围,利用加工因子校正评估模型更切合实际风险水平。

关键词：呋虫胺唑虫酰胺茶叶加工因子残留特征风险评估

Activating transcription factor 5 regulates lipid metabolism in adipocytes

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Science Bulletin 2016年第23期61卷 1802-1809页

作者： jing-Hui Jiang Yue Zhao Liu-Ling xiao Cui-Song Zhu shu-Fen Li xi Li Key Laboratory of Metabolic Molecular Medicine the Ministry of Education Department of Biochemistry and Molecular Biology Fudan University Basic Medical SchoolShanghai 200032 China Jiangsu Key Laboratory of Molecular Medicine School of Medicine Nanjing University Nanjing 210093 China Chongqing Medical University Chongqing 400016 China

Activating transcription factor 5(ATF5) is a member of the activating transcription factor/cA MP response element binding protein(ATF/CREB) family, and is highly expressed in liver and adipose tissue. Previous reports have shown that ATF5 promoted 3T3-L1 preadipocytes differentiation. In this study, we found that ATF5 was highly expressed in mature adipocytes, suggesting a potential role of ATF5 in mature adipocytes, which has not been reported previously. To understand the function of ATF5 in mature adipocytes, we knocked down the expression of ATF5 in 3T3-L1 mature adipocytes and observed decreased lipid droplets. Consistent with the in vitro experiment, the knockdown of ATF5 in white adipose tissue led to less adipose tissue and smaller adipocytes size. Further research revealed that the inhibition of ATF5 diminished the adipocytes size via the inhibition of fatty acid synthetase, stearyl coenzyme A desaturation enzyme 1, and the induction of carnitine palmitoyl transferase 1, one key enzyme of lipid metabolism. In addition, ATF5 knockdown in inguinal white adipose tissue improved whole body insulin *** work provides a new understanding of ATF5 function in mature adipocytes and a potential therapeutic target of diabetes.

关键词： Activating tra scription factor 5 Adipocytes Lipid metabolism.

Raster-scanning Donut simplifies MINFLUX and provides alternative implement on other scanning-based microscopes

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Light(Science & Applications) 2022年第10期11卷 2271-2275页

作者： xinzhu Xu shu Jia Peng xi Department of Biomedical Engineering College of Future TechnologyPeking UniversityBeijing 100871China Wallace H.Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory UniversityAtlantaGeorgia 30332USA UTS-SUStech Joint Research Centre for Bio-medical Materials&Devices Department of Biomedical EngineeringCollege of EngineeringSouthern University of Science and TechnologyShenzhenGuangdong 518055China National Biomedical Imaging Center Peking UniversityBeijing 100871China

A donut excitation moves around a single molecule with a zigzag configuration lattice by *** a method implemented in scanning fluorescence microscopy simplifies the conventional MINFLUX *** of hollow zero-intensity excitation,single-pixel detection,time-correlated single photon counting,and drift stabilization,the system achieves localization precision and resolution very close to conventional MINFLUX theoretically and *** averaged high-SNR reference,and pixel-registered intensity from a single molecule is essential to reconstruct localization in maximum likelihood *** performance reaching nearly conventional MINFLUX's,the proposed raster-scanning MINFLUX can inspire researchers expertized in STED or confocal setup to quickly transform to MINFLUX and develop for further exploring on bio-specimens or optical applications.

关键词： scanning excitation stabilization

Visualization of cristae and mtDNA interactions via STED nanoscopy using a low saturation power probe

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Light(Science & Applications) 2024年第9期13卷 1741-1756页

作者： Wei Ren xichuan Ge Meiqi Li jing Sun Shiyi Li shu Gao Chunyan Shan Baoxiang Gao Peng xi Department of Biomedical Engineering National Biomedical Imaging CenterCollege of Future TechnologyPeking UniversityBeijing 100871China Key Laboratory of Analytical Science and Technology of Hebei Province College of Chemistry and Material ScienceHebei UniversityBaoding 071002China School of Life Sciences Peking UniversityBeijing 100871China National Center for Protein Sciences Peking UniversityBeijing 100871China

Mitochondria are crucial organelles closely associated with cellular metabolism and *** DNA(mtDNA)encodes a variety of transcripts and proteins essential for cellular ***,the interaction between the inner membrane(IM)and mtDNA remains elusive due to the limitations in spatiotemporal resolution offered by conventional microscopy and the absence of suitable in vivo probes specifically targeting the ***,we have developed a novel fluorescence probe called HBmito Crimson,characterized by exceptional photostability,fluorogenicity within lipid membranes,and low saturation *** successfully achieved over 500 frames of lowpower stimulated emission depletion microscopy(STED)imaging to visualize the IM dynamics,with a spatial resolution of 40 *** utilizing dual-color imaging of the IM and mtDNA,it has been uncovered that mtDNA tends to habitat at mitochondrial tips or branch points,exhibiting an overall spatially uniform ***,the dynamics of mitochondria are intricately associated with the positioning of mtDNA,and fusion consistently occurs in close proximity to mtDNA to minimize pressure during cristae *** healthy cells,>66%of the mitochondria are Class III(i.e.,mitochondria>5μm or with>12 cristae),while it dropped to<18%in *** dynamics,orchestrated by cristae remodeling,foster the even distribution of ***,in conditions of apoptosis and ferroptosis where the cristae structure is compromised,mtDNA distribution becomes *** findings,achieved with unprecedented spatiotemporal resolution,reveal the intricate interplay between cristae and mtDNA and provide insights into the driving forces behind mtDNA distribution.

关键词： metabolism saturation utilizing

Hepatitis C Virus NS2 Protein Suppresses RNA Interference in Cells

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Virologica Sinica 2020年第4期35卷 436-444页

作者： Hui Zhou Qi Qian Ting shu Jiuyue Xu jing Kong jingfang Mu Yang Qiu xi Zhou State Key Laboratory of Virology College of Life SciencesWuhan UniversityWuhan 430072China State Key Laboratory of Virology Wuhan Institute of VirologyCenter for Biosafety Mega-ScienceChinese Academy of SciencesWuhan 430071China Center for Translational Medicine Wuhan Jinyintan HospitalWuhan 430040China University of Chinese Academy of Sciences Beijing 100049China

RNAi interference(RNAi)is an evolutionarily conserved post-transcriptional gene silencing mechanism and has been well recognized as an important antiviral immunity in *** viruses have been shown to encode viral suppressors of RNAi(VSRs)to antagonize antiviral *** C virus(HCV)is a medically important human pathogen that causes acute and chronic *** this study,we screened all the nonstructural proteins of HCV and found that HCV NS2 could suppress RNAi induced either by small hairpin RNAs(shRNAs)or small interfering RNAs(siRNAs)in mammalian ***,we demonstrated that NS2 could suppress RNAi via its direct interaction with doublestranded RNAs(dsRNAs)and siRNAs,and further identified that the cysteine 184 of NS2 is required for the RNAi suppression activity through a serial of point mutation ***,our findings uncovered that HCV NS2 can act as a VSR in vitro,thereby providing novel insights into the life cycle and virus-host interactions of HCV.

关键词： Hepatitis C virus(HCV) NS2 Antiviral RNAi Viral suppressor of RNAi(VSR)

Left-Right Non-Linear Dynamical Higgs

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Communications in Theoretical Physics 2016年第12期65卷 643-662页

作者： jing shu Juan Yepes State Key Laboratory of Theoretical Physics and Kavli Institute for Theoretical Physics China Institute of Theoretical Physics Chinese Academy of Sciences

All the possible CP-conserving non-linear operators up to the p^4-order in the Lagrangian expansion are analysed here for the left-right symmetric model in the non-linear electroweak chiral context coupled to a light dynamical Higgs. The low energy effects will be triggered by an emerging new physics field content in the nature, more specifically,from spin-1 resonances sourced by the straightforward extension of the SM local gauge symmetry to the larger local group SU(2)_L × SU(2)_R× U(1)_(B-L). Low energy phenomenology will be altered by integrating out the resonances from the physical spectrum, being manifested through induced corrections onto the left handed operators. Such modifications are weighted by powers of the scales ratio implied by the symmetries of the model and will determine the size of the effective operator basis to be used. The recently observed diboson excess around the invariant mass 1.8 TeV–2 TeV entails a scale suppression that suggests to encode the low energy effects via a much smaller set of effective operators.

关键词： left-right model nonlinear invariance CP symmetry SU(2)×SU(2)×U(1) effective Lagrangian Higgs couplings

Joint optimization of maintenance inspection and spare provisioning for aircraft deteriorating parts

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Journal of Systems Engineering and Electronics 2017年第6期28卷 1133-1140页

作者： jing Cai xin Li xi Chen College of Civil Aviation Nanjing University of Aeronautics and Astronautics Shanghai Aircraft Customer Service Co. Ltd.

With the wide application of condition based maintenance(CBM) in aircraft maintenance practice, the joint optimization of maintenance and inventory management, which can take full advantage of CBM and reduce the aircraft operational cost, is receiving increasing attention. In order to optimize the inspection interval, maintenance decision and spare provisioning together for aircraft deteriorating parts, firstly, a joint inventory management strategy is presented, then, a joint optimization of maintenance inspection and spare provisioning for aircraft parts subject to the Wiener degradation process is proposed based on the ***, a combination of the genetic algorithm(GA) and the Monte Carol method is developed to minimize the total cost ***, a case study is conducted and the proposed joint optimization model is compared with the existing optimization model and the airline real case. The results demonstrate that the proposed model is more beneficial and effective. In addition, the sensitivity analysis of the proposed model shows that the lead time has higher influence on the optimal results than the urgent order cost and the corrective maintenance cost, which is consistent with the actual situation of aircraft maintenance practices and inventory management.

关键词： joint optimization maintenance spare provision aircraft part Wiener process

Mass Spectrometric Fragmentation of 1-(Benzyloxycarbonyl)amino-2-alkyl/cycloalkyl Thioacetates:a Thioester Pyrolysis-type Rearrangement under Electron Impact Ionization

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Chinese Chemical Letters 2006年第8期17卷 1069-1072页

作者： shu XU Jia xi XU Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education College of Chemistry and Molecular Engineering Peking University Beijing 100871

The mass spectrometric fragmentation of 1-（benzyloxycarbonyl）amino-2-alkyl/cycloalkyl thioacetates has been studied with the aid of mass-analysed ion kinetic energy spectrometry under electron impact ionization. All compounds show a tendency to eliminate a ketene, thioacetic acid, and benzyl carbamate molecule, or an acetyl and benzyloxy radicals. A thioester pyrolysis-type rearrangement under electron impact ionizations was observed.

关键词： Electron impact ionization mass spectrometry rearrangement thioacetate.