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Hormetic response of cholinesterase from Daphnia magna in chronic exposure to triazophos and chlorpyrifos

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Journal of Environmental Sciences 2011年第5期23卷 852-859页

作者： Shaonan Li yajun tan Institute of Pesticide and Environmental Toxicology College of Agriculture and Biotechnology Zhejiang University Hangzhou 310029 China. E-mail: snli@*** Research Institute of Tianjin Product Quality Inspection Technology Tianjin 300384 China

In vivo activity of cholinesterase （ChE） in Daphnia magna was measured at different time points during 21-day exposure to triazophos and chlorpyrifos ranging from 0.05 to 2.50 μg/L and 0.01 to 2.00 μg/L, respectively. For exposure to triazophos, ChE was induced up to 176.5% at 1.5 μg/L and day 10 when measured by acetylthiocholine （ATCh）, whereas it was induced up to 174.2% at 0.5 μg/L and day 10 when measured by butyrylthiocholine （BTCb）. For exposure to chlorpyrifos, ChE was induced up to 134.0% and 160.5% when measured by ATCh and BTCh, respectively, with both maximal inductions detected at 0.1 Ixg/L and day 8. Obvious induction in terms of ChE activity was also detected in daphnia removed from exposures 24 hr after their birth and kept in a recovery culture for 21 days. Results indicated that the enzyme displayed symptoms of hormesis, a characteristic featured by conversion from low-dose stimulation to high-dose inhibition. In spite of that, no promotion in terms of reproduction rate and body size was detected at any tested concentrations regardless of whether the daphnia were collected at end of the 21-day exposure or at end of a 21-day recovery culture. This suggested that induction of ChE caused by anticholinesterases had nothing to do with the prosperity of the daphnia population.

关键词： Daphnia magna anticholinesterase ChE enzyme promotion exposure recovery culture population prosperity

GO/MgO/Mg interface mediated strengthening and electromagnetic interference shielding in AZ31 composite

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Journal of Magnesium and Alloys 2023年第10期11卷 3800-3814页

作者： Z.y.Xu C.F.Fang C.J.Li R.Wang X.P.Zhang J.tan y.M.Wang Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116024China Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China College of Materials Science and Engineering Chongqing UniversityChongqing 400045China Key Laboratory of Materials Modification by Laser Ion and Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian 116023China

More requirements of electromagnetic interference(EMI) shielding performance are put forward for lightweight structural materials due to the development of aerospace and 5G communications. Herein, graphene oxide(GO) decorated with SnO_(2) coating is introduced as reinforcement into AZ31 Mg alloy. During the smelting process, the MgO layer is in situ gernerated at interface between GO and the molten Mg alloy matrix by consuming SnO_(2). In the solid state, such kind of interface structure can improve the GO-Mg interface bonding intensity,also significantly generate stacking faults. The AZ31 composite reinfoced by trace modified GO(0.1 wt%) exhibits high ultimate strength and almost the same elongation with AZ31 alloy. Compared with AZ31 alloy, the yield strength and ultimate tensile strength of composite are increased by 33.5% and 23.7%, respectively. Meanwhile, the multi-level electromagnetic reflection from the multi-layer structure of GO and the interface polarization caused by the MgO mid-layer can significantly improve EMI shielding performance. The appropriate interface design strategy achieves the effect of “two birds with one stone”.

关键词： Metal-matrix composites Mechanical properties EMI shielding Microstructures

Are children on jejunal feeds at risk of iron deficiency?

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World Journal of Gastroenterology 2015年第18期21卷 5751-5754页

作者： Li-Zsa tan Susan E Adams Alison Kennedy Helen Kepreotes Chee y Ooi Department of Gastroenterology Sydney Children’s Hospital Department of Surgery Sydney Children’s Hospital Discipline of Paediatrics School of Women’s and Children’s Health Medicine University of New South Wales Department of Dietetics Sydney Children’s Hospital

Children on exclusive jejunal feeding may be at risk of iron deficiency due to the feeds bypassing the duodenum,which is the primary site for iron *** describe the biochemical and hematological features of six children on exclusive jejunal feeding who did not receive iron *** a mean(standard deviation)period of 11(6.5)mo after commencing jejunal feeds,there was a significant reduction in both serum iron(18.5 g/L vs 9.8 g/L,P=0.01)and transferrin saturation levels(23.1%vs 13.7%,P=0.02),suggesting iron ***,there was no significant change in ferritin,hemoglobin and mean corpuscular volume levels post-commencement of jejunal *** may be the result of small bowel adaptation in response to early iron *** and longer term prospective studies are required to investigate if children on jejunal feeds are at risk of developing iron deficiency.

关键词： Iron deficiency Exclusive jejunal feeds Jejunally fed children

The combined effects of grain and sample sizes on the mechanical properties and fracture modes of gold microwires

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Journal of Materials Science & Technology 2019年第1期35卷 76-83页

作者： H.K.yang K.Cao y.Han M.Wen J.M.Guo Z.L.tan J.Lu y.Lu Hong Kong Branch of National Precious Metals Material Engineering Research Center City University of Hong Kong Department of Mechanical and Biomedical Engineering City University of Hong Kong State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals Sino-platinum Metals Co.Ltd Center for Advanced Structural Materials City University of Hong Kong Shenzhen Research Institute

Hall-Petch relation was widely applied to evaluate the grain size effect on mechanical properties of metallic material. However, the sample size effect on the Hall-Petch relation was always ignored. In the present study, the mechanical test and microstructure observation were performed to investigate the combined effects of grain and sample sizes on the deformation behaviors of gold microwires. The polycrystalline gold microwires with diameter of 16 ?m were annealed at temperatures from 100°C to 600°C, leading to different ratios(t/d) of wire diameter(t) to grain size(d) from 0.9 to 16.7. When the t/d was lower than 10, the yield stress dropped fast and deviated from the Hall-Petch relation. The free-surface grains played key role in the yield stress softening, and the volume fraction of free-surface grains increased with the t/d decreasing. Furthermore, the effects of t/d on work-hardening behaviors and fracture modes were also studied. With t/d value decreasing from 17 to 3.4, the samples exhibited necking fracture and the dislocation pile-ups induced work-hardening stage was gradually *** the t/d value further decreasing(t/d y lost. As the gold microwire for wire bonding is commonly applied in the packaging of integrated circuit chips, and the fabrication of microwire suffers multi-pass cold-drawing and annealing treatments to control the grain size. The present study could provide instructive suggestion for gold microwire fabrication and bonding processes.

关键词： Gold microwire Wire bonding Tensile testing Grain size Hall-Petch relationship

线粒体损伤和NLRP3炎症小体信号在年龄相关性黄斑变性中的研究进展

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眼科新进展 2025年第1期45卷 60-65页

作者：邹悦李云琴谭欣蒋俊良云南大学附属医院(云南省第二人民医院云南省眼科医院)云南省昆明市650021

年龄相关性黄斑变性(AMD)是一种导致严重视力丧失的眼病。该病症的关键病理特征之一是视网膜的神经炎症反应。NLRP3炎症小体在调节这种神经炎症中扮演着至关重要的角色。研究表明,在AMD的发展过程中,NLRP3炎症小体的激活与线粒体的损伤... 详细信息

年龄相关性黄斑变性(AMD)是一种导致严重视力丧失的眼病。该病症的关键病理特征之一是视网膜的神经炎症反应。NLRP3炎症小体在调节这种神经炎症中扮演着至关重要的角色。研究表明,在AMD的发展过程中,NLRP3炎症小体的激活与线粒体的损伤、活性氧的产生及线粒体DNA的异常释放紧密相关。因此,针对NLRP3炎症小体的抑制剂可能成为一种对AMD治疗极具潜力的新方法。本文对线粒体损伤与NLRP3炎症小体信号途径在AMD发病机制中的作用进行了全面综述,展望了这一领域的研究进展。

关键词：年龄相关性黄斑变性炎症小体线粒体神经炎症

Microstructural features of Ti-6Al-4V manufactured via high power laser directed energy deposition under low-cycle fatigue

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Journal of Materials Science & Technology 2021年第24期83卷 18-33页

作者： y.M.Ren X.Lin H.O.yang H.tan J.Chen Z.y.Jian J.Q.Li W.D.Huang School of Materials and Chemical Engineering Xi’an Technological UniversityXi’an710021China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an710072China

Laser additive manufacturing(LAM)technique has unique advantages in producing geometrically complex metallic ***,the poor low-cycle fatigue property(LCF)of LAM parts restricts its widely ***,the microstructural features of a Ti-6 Al-4 V alloy manufactured via high power laser directed energy deposition subjected to low-cycle fatigue loading were *** fatigue loading,the microstructure of the as-deposited parts was found to exhibit a non-homogeneous distribution of columnar prior-βgrains(200-4000μm)at various scanning velocities(300-1500 mm/min)and relatively coarseα-laths(1.0-4.5μm).Under cyclic loading,fatigue microcracks typically initiated within the alignedαphases in the preferred orientation(45°to the loading direction)at the surface of the fatigue *** Ti-6 Al-4 V exhibited a single straight dislocation character at low strain amplitudes(tangled dislocations at high strain amplitudes(>1.1%).In addition,dislocation substructure features,such as dislocation walls,stacking faults,and dislocation networks,were also *** findings may provide opportunities to understand the fatigue failure mechanism of additive manufactured titanium parts.

关键词： Laser additive manufacturing Directed energy deposition Titanium alloy Low-cycle fatigue Microstructure

Strengthening and deformation mechanism of high-strength CrMnFeCoNi high entropy alloy prepared by powder metallurgy

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Journal of Materials Science & Technology 2023年第1期132卷 119-131页

作者： y.Xing C.J.Li y.K.Mu y.D.Jia K.K.Song J.tan G.Wang Z.Q.Zhang J.H.yi J.Eckert Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China Laboratory for Microstructures Institute of MaterialsShanghai UniversityShanghai 200444China School of Mechanical Electrical&Information EngineeringShandong UniversityWeihai 264209China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Erich Schmid Institute of Materials Science Austrian Academy of SciencesJahnstraße 12Leoben A-8700Austria Department of Materials Science Chair of Materials PhysicsMontanuniversität LeobenJahnstraße 12Leoben A-8700Austria Adjunct with National University of Science and Technology«MISiS» Leninsky Prosp.4Moscow 119049Russia

Multiphase CrMnFeCoNi high-entropy alloys(HEAs)were prepared by a powder metallurgy process com-bining mechanical alloying(MA)and vacuum hot-pressing sintering(HPS).The single-phase face-centered cubic(FCC)HEA powder prepared by MA was sintered into a bulk HEA specimen containing FCC phase matrix along with precipitated M 23 C 6 phase and nanoscaleσphase *** the sintering temper-ature was 1223 K,the ultimate strength reaches 1300±11.6 MPa,and the elongation exceeds 4%±0.6%.Microstructural characterization reveals that the formation of nanoscale particles and deformation twins play critical roles in improving the strain hardening(SH)*** the MA time promoted the formation of the precipitated phase and enhanced the SH ability by increasing the number of precip-itated *** SH capacity increases significantly with increasing sintering temperature,which is attributed to a significant enhancement in the twinning capacity due to grain growth and the reduced number ofσphase *** systematic studies,the planar glide of dislocations was found to be the main mode of deformation,while deformation twinning appeared as an auxiliary deformation mode when the twinning stress was *** the formation of precipitates leads to grain bound-ary and precipitation strengthening effects,crack initiation is more prominent owing to increased grain boundary brittleness around the precipitated M 23 C 6 *** prominence of crack initiation is a contra-diction that must be reconciled with regard to precipitation *** work serves as a useful reference for the preparation of high-strength HEA parts by powder metallurgy.

关键词： High entropy alloy Powder processing Grain reﬁnement Precipitation strengthening Deformation twinning

Recent Advances in Understanding Proteins Involved in Lipid Droplet Formation, Growth and Fusion

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Journal of Genetics and Genomics 2014年第5期41卷 251-259页

作者： Jolene S.y.tan Colin J.P.Seow Vera J.Goh David L.Silver Signature Research Program in Cardiovascular & Metabolic Disorders Duke-NUS Graduate Medical School Singapore

Lipid droplets （LDs） were once viewed as simple, inert lipid micelles. However, they are now known to be organelles with a rich proteome involved in a myriad of cellular processes. LDs are heterogeneous in nature with different sizes and compositions of phospholipids, neutral lipids and proteins. This review takes a focused look at the roles of proteins involved in the regulation of LD formation, expansion, and morphology. The related proteins are summarized such as the fat-specific protein （Fsp27）, fat storage-inducing trans- membrane （FIT） proteins, seipin and ADP-ribosylation factor 1-coat protein complex I （Arf-COPI）. Finally, we present important challenges in LD biology for a deeper understanding of this dynamic organelle to be achieved.

关键词： Lipid droplets LD-associated proteins Perilipin Phospholipids

A Novel Extremum Seeking Control to Enhance Convergence and Robustness in the Presence of Nonlinear Dynamic Sensors

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Journal of Systems Science & Complexity 2024年第1期37卷 3-21页

作者： LIU Hengchang tan ying OETOMO Denny School of Electrical Mechanical and Infrastructure EngineeringThe University of MelbourneParkville VIC 3010Australia

This paper focuses on optimizing an unknown cost function through extremum seeking(ES)control in the presence of a slow nonlinear dynamic sensor responsible for measuring the *** contrast to traditional perturbation-based ES control,which often suffers from sluggish convergence,the proposed method eliminates the time-scale separation between sensor dynamics and ES control by using the relative degree of the nonlinear sensor *** improve the convergence rate,the authors incorporate high-frequency dither signals and a *** enhance the robustness with the existence of rapid disturbances,an off-the-shelf linear high-gain differentiator is *** first result demonstrates that,for any desired convergence rate,with properly tuned parameters for the proposed ES algorithm,the input of the cost function can converge to an arbitrarily small neighborhood of the optimal solution,starting from any initial condition within any given compact ***,the second result shows the robustness of the proposed ES control in the presence of sufficiently fast,zero-mean periodic *** results substantiate these theoretical findings.

关键词： Averaging extremum seeking optimization singular perturbation time-scale separation