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Regenerative medicine of pancreatic islets

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World Journal of Gastroenterology 2020年第22期26卷 2948-2966页

作者： Irina v Arutyunyan Timur Kh Fatkhudinov andrey v Makarov andrey v Elchaninov Gennady T Sukhikh National Medical Research Center for Obstetrics Gynecology and Perinatology named after Academician V.I.Kulakov of Ministry of Healthcare of Russian FederationMoscow 117997Russia Research Institute of Human Morphology Moscow 117418Russia Peoples Friendship University of Russia Moscow 117198Russia Pirogov Russian National Research Medical University Ministry of Healthcare of the Russian FederationMoscow 117997Russi

The pancreas became one of the first objects of regenerative medicine,since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly *** number of people living with diabetes mellitus is currently approaching half a billion,hence the crucial relevance of new methods to stimulate regeneration of the insulin-secretingβ-cells of the islets of *** restrictions on the islet regeneration are very tight;nevertheless,the islets are capable of physiological regeneration viaβ-cell self-replication,direct differentiation of multipotent progenitor cells and spontaneousα-toβ-orδ-toβ-cell conversion(trans-differentiation).The existing preclinical models ofβ-cell dysfunction or ablation(induced surgically,chemically or genetically)have significantly expanded our understanding of reparative regeneration of the islets and possible ways of its *** ultimate goal,sufficient level of functional activity ofβ-cells or their substitutes can be achieved by two prospective broad strategies:β-cell replacement andβ-cell ***“regeneration”strategy aims to maintain a preserved population ofβ-cells through in situ exposure to biologically active substances that improveβ-cell survival,replication and insulin secretion,or to evoke the intrinsic adaptive mechanisms triggering the spontaneous non-β-toβ-cell ***“replacement”strategy implies transplantation ofβ-cells(as non-disintegrated pancreatic material or isolated donor islets)orβ-like cells obtained ex vivo from progenitors or mature somatic cells(for example,hepatocytes orα-cells)under the action of small-molecule inducers or by genetic *** believe that the huge volume of experimental and clinical studies will finally allow a safe and effective solution to a seemingly simple goal-restoration of the functionally activeβ-cells,the innermost hope of millions of people globally.

关键词： Pancreas Islets of langerhans β-cells Regeneration Replacement Transplantation Reprogramming

Studies of ultrasonic dehydration efficiency

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第4期12卷 247-254页

作者： vladimir N. KHMELEv andrey v. SHALUNOv Roman v. BARSUKOv Denis S. ABRAMENKO andrey N. LEBEDEv Biysk Technological Institute (Branch) Altai State Technical University

The aim of this investigation was to define the effectiveness of non-contact drying using ultrasonic vibrations. Disk radiators were used for carrying out experiments, and a special drying chamber was designed to provide resonant amplification of ultrasonic vibrations (from 130 to 150 dB). Drying of ginseng and other vegetables demonstrated that the application of ultrasonic vibrations reduced power inputs by 20% in comparison with convective drying. It also led to a decrease of 6% in final moisture content, if the duration of drying was constant. The level of intensification of ultrasonic drying was high (up to 50 g for 1 kg of drying material), which helped to lower the temperature of the drying agent and improve the quality of the dried products.

关键词： Drying Ultrasound vibration system Drying chamber Processing (treatment) of agricultural products

Autonomous UAv 3D trajectory optimization and transmission scheduling for sensor data collection on uneven terrains

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Defence Technology（防务技术） 2023年第12期30卷 154-160页

作者： andrey v.Savkin Satish C.verma Wei Ni School of Electrical Engineering and Telecommunications University of New South WalesSydneyAustralia Data61 CSIROCanberraACT2601Australia

This paper considers a time-constrained data collection problem from a network of ground sensors located on uneven terrain by an Unmanned Aerial vehicle(UAv),a typical Unmanned Aerial System(UAS).The ground sensors harvest renewable energy and are equipped with batteries and data *** ground sensor model takes into account sensor data buffer and battery *** asymptotically globally optimal method of joint UAv 3D trajectory optimization and data transmission schedule is *** developed method maximizes the amount of data transmitted to the UAv without losses and too long delays and minimizes the propulsion energy of the *** developed algorithm of optimal trajectory optimization and transmission scheduling is based on dynamic *** simulations demonstrate the effectiveness of the proposed algorithm.

关键词： Unmanned aerial system UAS Unmanned aerial vehicle UAv Wireless sensor networks UAS-Assisted data collection 3D trajectory optimization Data transmission scheduling

Energy-efficient joint UAv secure communication and 3D trajectory optimization assisted by reconfigurable intelligent surfaces in the presence of eavesdroppers

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Defence Technology（防务技术） 2024年第1期31卷 537-543页

作者： Huang Hailong Mohsen Eskandari andrey v.Savkin Wei Ni The Department of Aeronautical and Aviation Engineering The Hong Kong Polytechnic UniversityHong KongChina School of Electrical Engineering and Telecommunications University of New South WalesSydney2052Australia Data61 CSIROAustralia

We consider a scenario where an unmanned aerial vehicle(UAv),a typical unmanned aerial system(UAS),transmits confidential data to a moving ground target in the presence of multiple *** friendly reconfigurable intelligent surfaces(RISs) help to secure the UAv-target communication and improve the energy efficiency of the *** formulate an optimization problem to minimize the energy consumption of the UAv,subject to the mobility constraint of the UAv and that the achievable secrecy rate at the target is over a given *** present an online planning method following the framework of model predictive control(MPC) to jointly optimize the motion of the UAv and the configurations of the *** effectiveness of the proposed method is validated via computer simulations.

关键词： Unmanned aerial systems(UASs) Unmanned aerial vehicle(UAv) Communication security Eaves-dropping Reconfigurable intelligent surfaces(RIS) Autonomous navigation and placement Path planning Model predictive control

Acoustic emission characterization of sliding wear under condition of direct and inverse transformations in lowtemperature degradation aged Y-TZP and Y-TZP-Al_2O_3

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Friction 2018年第3期6卷 323-340页

作者： Nikolai L SAvCHENKO andrey v FILIPPOv Sergei Yu TARASOv andrey I DMITRIEv Evgeny v SHILKO Aleksandr S GRIGORIEv Institute of Strength Physics and Materials Science SB RAS National Research Tomsk Polytechnic University National Research Tomsk State University

In this research, results of the investigation of the sliding friction and wear of yttria-stabilized tetragonal zirconia polycrystalline(Y-TZP) and Y-TZP-Al_2O_3 samples preliminarily subjected to low-temperature degradation are reported. The investigation was carried out using a pin-on-disk tribometer with simultaneous recording of acoustic emission(AE) and vibration acceleration. The sliding wear process was found to be determined by dynamic direct and inverse Y-TZP transformations detected by monoclinic and tetragonal X-ray diffraction peak ratios. The AE signals generated under direct and inverse transformations can be used to characterize wear and friction mechanisms as well as direct and inversed sliding-induced phase transformations. The AE signal energy grows with the friction coefficient and the inverse transformation degree. Reduction of the AE signal energy indicates establishing the mild wear stage caused by effective stress-induced direct martensitic transformation. The AE signal median frequency increases in the case of lower friction. Numerical studies of wear subsurface fracture under conditions of stress-induced martensitic transformation were used to elucidate the role played by the phase transformation in Y-TZP and Y-TZP-Al_2O_3. Martensitic transformation in Y-TZP was described with use of the non-associated dilatant plasticity model. Simulation results particularly show that increase in the value of dilatancy coefficient from 0 to 0.2 is accompanied by 25%-30% reduce in characteristic length and penetration depth of sliding-induced subsurface cracks. As shown the AE may be an effective tool for in-situ monitoring the subsurface wear of materials experiencing both direct and inverse transformations.

关键词： zirconia transformation toughening low-temperature degradation friction acoustic emission numerical modeling movable cellular automata method

Substituted diamides of dipicolinic acid as extractants and ionophores for rare earth metals

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Journal of Rare Earths 2023年第8期41卷 1234-1241,I0005页

作者： Yingchao Ren valery A.Polukeev Ekaterina v.Kenf Liudmila I.Tkachenko Mikhail Yu Alyapyshev vasily A.Babain andrey v.Nechaev andrey v.Legin Dmitry O.Kirsanov Institute of Chemistry Saint-Petersburg UniversityPeterhofUniversitetsky Prospect 26198504Saint-PetersburgRussia JSvC vekton Ul.2-oy Luch 9192019Saint-PetersburgRussia Khlopin Radium Institute 194021282nd Murinsky avRussia ThreeArc Mining LLC Pr.Narodnogo Opolchenia 10198216Saint-PetersburgRussia Rusredmet Vosstanovleniya str.15bl.3198320St.PeterburgKrasnoe seloRussia

The variety of newly synthesized diamides of dipicolinic acid(DPA)bearing methyl-and oxymethyl substituents in various positions of phenyl ring was investigated as potential ligands for liquid-liquid extraction of rare earth metal ions and as membrane active compounds in plasticized polymeric membranes of potentiometric *** is found that scandium is extracted with 2,6-pyridinedicarboxylic acid diamides similarly to heavy lanthanides,while yttrium is extracted together with light group *** shows high selectivity for the separation of cadmium/zinc,lead/nickel or copper/nickel *** four out of six studied ligands demonstrate significant potentiometric sensitivity towards scandium,yttrium and lanthanides in 10^(-7)-10^(-3)mol/L concentration range in nitric acid *** trends in sensitivity values vary depending on a ligand structure and the highest values are observed for Sc^(3+)and heavy *** to the evaluated selectivity Sm^(3+)is the most preferred ion,while La^(3+)is the most *** differences in sensor behavior in rare earth metal solutions assume that such devices can be applied in sensor arrays for potentiometric analysis of lanthanide mixtures.

关键词： Dipicolini cacid diamides Scandium Yttrium Lanthanides Extraction Potentiometric sensors

Juvenile survival curves in a solitary ground squirrel with a prolonged hibernation:effects of individual characteristics,environment,and maternal investment

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Current Zoology 2024年第1期70卷 13-23页

作者： Nina A.vasilieva Liudmila E Savinetskaya andrey v.Tchabovsky A.N.Severtsov Institute of Ecology and Evolution Russian Academy of SciencesMoscow 119071Russia

Juvenile survival is a key life-history influence on population dynamics and adaptive *** analyzed the effects of individual chara-cteristics,early environment,and maternal investment on juvenile survival in a large solitary hibernating rodent-yellow ground squirrel Spermophilus fulvus using Cox mixed-effects *** 48%of weaned pups survived to dispersal and 17%survived to *** life expectancy was primarily determined by individual characteristics and,to a lesser extent,by the early *** strongest and pos-itive predictor of juvenile survival was body mass which crucially affected mortality immediately after *** suffered higher mortality than females after the onset of dispersal;however,the overall difference between sexes was partly masked by high rates of mortality in the first days after emergence in both *** emerged juveniles had lower life expectancy than the earliest *** overall effect of local juvenile density was *** lactation did not enhance juvenile survival:Pups nursed longer survived shorter than the young nursed for a shorter *** findings support the hypothesis that females of *** cannot effectively regulate maternal expenditures to mitigate the effects of unfavorable conditions on their *** strategy to deal with seasonal time constraints on life history in female *** suggests an early termination of maternal care at the cost of juvenile quality and *** female reproductive strategy corresponds to a"fast-solitary"life of folivorous desert-dwelling *** and other solitary ground squirrels with prolonged hibernation.

关键词： early-life conditions ground squirrels hibernation juvenile mortality maternal investment survival curves

Age of maturation and behavioral tactics in male yellow ground squirrel Spermophilus fulvus during mating season

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Current Zoology 2014年第6期60卷 700-711页

作者： Nina A. vASILIEvA Ekaterina v. PAvLOvA Sergey v. NAIDENKO andrey v.TCHABOvSKY A.N. Severtsov Institute of Ecology and Evolution Russian Academy of Sciences 33 Leninsky pr. Moscow 119071 Russia

Life-history theory predicts that in hibemators age of maturation is related positively to body size and negatively to the duration of active season aboveground. Yellow souslik is a large-sized ground squirrel with long hibernation, which suggests late maturation. We used four-year field observations of marked individuals to determine the age of maturation in males through analysis of age-dependent variation in body size, mass, androgen status, timing of spring emergence, ranging patterns and social behavior during the mating season. Yearling males were smaller, lighter, had lower level of fecal testosterone, emerged later and had smaller home ranges than older males. Social activity and the number of females encountered did not differ between age classes. After the second hibernation none of the studied parameters varied with age. Cluster analysis revealed two behavioral tactics：＂active＂ males （adults only） emerged earlier, ranged more widely, initiated more contacts, encountered more females and were heavier than ＂passive＂ males （both yearling and adult）. Thus, males of S. fulvus reached adult size and matured after two hibernations, which is relatively fast for such a big species with short active period. Indirect evidence for copulations and high variation among yearlings in all parameters suggest that some of them might successfully compete with adults. Active tactic of wandering and searching for females is energetically costly, and probably only adult males in good physical condition can afford it, whereas passive tactic of residing is energy saving and good for adults in poor condition and for yearlings that are continuing to grow.

关键词： Age of maturation Mating system Reproductive tactics Ground squirrel Spermophilusfulvus

Neuromorphic nanocluster networks:Critical role of the substrate in nano-link formation

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Nano Research 2023年第7期16卷 10500-10506页

作者： Wenkai Wu Alexey v.verkhovtsev Theodoros Pavloudis andrey v.Solov’yov Richard E.Palmer Nanomaterials Lab Faculty of Science and EngineeringSwansea UniversityBay CampusFabian WaySA18ENSwanseaUK MBN Research Center Altenhöferallee 360438 Frankfurt am MainGermany School of Physics Faculty of SciencesAristotle University of ThessalonikiGR-54124 ThessalonikiGreece

Atomic cluster-based networks represent a promising architecture for the realization of neuromorphic computing systems,which may overcome some of the limitations of the current computing *** formation and breakage of links between the clusters are of utmost importance for the functioning of these computing *** paper reports the results of molecular dynamics simulations of synapse(bridge)formation at elevated temperature and thermal breaking processes between 2.8 nmsized Au1415 clusters deposited on a carbon substrate,a model ***,we find that the bridge formation process is driven by the diffusion of gold atoms along the substrate,no matter how small the gap between the clusters *** complementary simulations of the bridge breaking process reveal the existence of a threshold bias voltage to activate bridge rupture via Joule *** results provide an atomistic-level understanding of the fundamental dynamical processes occurring in neuromorphic cluster arrays.

关键词： atomic-switch network nanoclusters nanoparticles(NPs) clusters on surfaces synapse neuromorphics molecular dynamics(MD)