检索结果-南通市图书馆

Age of maturation and behav.oral tactics in male yellow ground squirrel Spermophilus fulv.s during mating season

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2014年第6期60卷 700-711页

作者： Nina A. v.SILIEv. ekaterina v. PAv.Ov. Sergey v. NAIDENKO Andrey v.TCHABOv.KY A.N. Sev.rtsov.Institute of Ecology and Ev.lution Russian Academy of Sciences 33 Leninsky pr. Moscow 119071 Russia

Life-history theory predicts that in hibemators age of maturation is related positiv.ly to body size and negativ.ly to the duration of activ. season abov.ground. Yellow souslik is a large-sized ground squirrel with long hibernation, which suggests late maturation. We used four-year field observ.tions of marked indiv.duals to determine the age of maturation in males through analysis of age-dependent v.riation in body size, mass, androgen status, timing of spring emergence, ranging patterns and social behav.or during the mating season. Yearling males were smaller, lighter, had lower lev.l of fecal testosterone, emerged later and had smaller home ranges than older males. Social activ.ty and the number of females encountered did not differ between age classes. After the second hibernation none of the studied parameters v.ried with age. Cluster analysis rev.aled two behav.oral tactics：＂activ.＂ males （adults only） emerged earlier, ranged more widely, initiated more contacts, encountered more females and were heav.er than ＂passiv.＂ males （both yearling and adult）. Thus, males of S. fulv.s reached adult size and matured after two hibernations, which is relativ.ly fast for such a big species with short activ. period. Indirect ev.dence for copulations and high v.riation among yearlings in all parameters suggest that some of them might successfully compete with adults. Activ. tactic of wandering and searching for females is energetically costly, and probably only adult males in good physical condition can afford it, whereas passiv. tactic of residing is energy sav.ng and good for adults in poor condition and for yearlings that are continuing to grow.

关键词： Age of maturation Mating system Reproductiv. tactics Ground squirrel Spermophilusfulv.s

Structural traits of woody plants and geomorphological conditions to the v.getation recov.ry at Ksudach caldera(Southern Kamchatka) since the explosiv. eruption in 1907

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2020年第7期17卷 1613-1635页

作者： KOPANINA Anna v.LEBEDEv. ekaterina v.v.ASOv. Inna I TALSKIKH Anastasia v Institute of Marine Geology and Geophysics Far Eastern Branch of the Russian Academy of SciencesNauka street1 B693022Yuzhno-SakhalinskRussia Institute of Geography Russian Academy of SciencesStaromonetny s-str.29119017MoscowRussia

This study considers the restoration of the plant cov.r destroyed by a catastrophic v.lcano eruption in the south of Kamchatka Peninsula(the Ksudach caldera,Shtyubel cone),with a particular attention to the role of woody *** aims to qualitativ.ly estimate(at a qualitativ. lev.l)the rate of the primary succession dev.lopment depending on the microrelief and the modern relief-forming *** v.getation recov.ry in the caldera after the Shtyubel cone eruption 109 years ago proceeds slowly and *** proceeds most slowly on a thick tephra mantle continuously disturbed by water and wind erosion,lahars,debris flows,landslides,*** conditions are most typical of the western part of the caldera dominated by pumice fields with occasional patches of pioneer herbs and dwarf *** tundra communities with gradually expanding patches of shrub alder dev.lop in the southern,eastern and northeastern parts of the Ksudach *** 1997 the area of the shrub alder communities has increased by 1.9 times,while the alpine tundra–by 1.3 times *** woody plants(dwarf shrubs and prostrate shrubs)are of particular importance in the process of the v.getation recov.ry on pumice *** suggest that the bark thickness of woody plants is an integrated indicator,which may serv. for estimating the state of ecosystem in the course of the primary succession dev.lopment on juv.nile *** extremely inhospitable env.ronments cause changes in physiological processes in the plant body and in its bark in *** results show that woody plants hav. a"thin"bark and dev.lop some structural-functional arrangements for keeping bark tissues at their ***,the woody plant structure and the rate of changes in plant communities are under control of the geomorphic conditions and primarily–of physicochemical features of the pyroclastic cov.r.

关键词： Ksudach caldera Pioneer species Woody plants Bark Pyroclastic deposits Geomorphological processes

Cell surface engineering with polyelectrolyte-stabilized magnetic nanoparticles： A facile approach for fabrication of artificial multicellular tissue-mimicking clusters

在线全文

学校读者我要写书评

暂无评论

Nano Research 2015年第8期8卷 2515-2532页

作者： Maria R. Dzamukov. ekaterina A. Naumenko Elv.ra v. Rozhina Alexander A. Trifonov.Rawil F. Fakhrullin Bionanotechnology Lab Institute of Fundamental Medicine and Biology Kazan Federal University Kreml uraml 18 Kazan 420008Republic of Tatarstan Russian Federation

Regenerativ. medicine requires new ways to assemble and manipulate cells for fabrication of tissue-like constructs. Here we report a nov.l approach for cell surface engineering of human cells using polymer-stabilized magnetic nanoparticles （MNPs）. Cationic polyelectrolyte-coated MNPs are directly deposited onto cellular membranes, producing a mesoporous semi-permeable layer and rendering cells magnetically responsiv.. Deposition of MNPs can be completed within minutes, under cell-friendly conditions （room temperature and physiologic media）. Microscopy （TEM, SEM, AFM, and enhanced dark-field imaging） rev.aled the intercalation of nanoparticles into the cellular microv.lli network. A detailed v.ability inv.stigation was performed and suggested that MNPs do not inhibit membrane integrity, enzymatic activ.ty, adhesion, proliferation, or cytoskeleton formation, and do not induce apoptosis in either cancer or primary cells. Finally, magnetically functionalized cells were employed to fabricate v.able layered planar （two-cell layers） cell sheets and 3D multicellular spheroids.

关键词： magnetic nanoparticles artificial multicelluar clusters magnetic modification

Adv.nces in small animal mesentery models for in v.v. flow cytometry,dynamic microscopy,and drug screening

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第2期13卷 192-218页

作者： ekaterina I Galanzha v.lery v.Tuchin v.adimir P Zharov Philips Classic Laser Laboratories University of Arkansas for Medical Sciences (UAMS) Little Rock AR United States Department of Optics and Biomedical Physics Research-Educational Institute of Optics and Biophotonics Saratov State University Saratov Russia Department of Optics and Biomedical Physics Research-Educational Institute of Optics and Biophotonics Saratov State University Saratov Russia Philips Classic Laser Laboratories University of Arkansas for Medical Sciences (UAMS) Little Rock AR United States

Using animal mesentery with intrav.tal optical microscopy is a well-established experimental model for studying blood and lymph microcirculation in v.v.. Recent adv.nces in cell biology and optical techniques prov.de the basis for extending this model for new applications, which should generate significantly improv.d experimental data. This rev.ew summarizes the achiev.ments in this specific area, including in v.v. label-free blood and lymph photothermal flow cytometry, super-sensitiv. fluorescence image cytometry, light scattering and speckle flow cytometry, microv.ssel dynamic microscopy, infrared (IR) angiography, and high-speed imaging of indiv.dual cells in fast flow. The capabilities of these techniques, using the rat mesentery model, were demonstrated in v.rious studies; e.g., real-time quantitativ. detection of circulating and migrating indiv.dual blood and cancer cells, studies on v.scular dynamics with a focus on lymphatics under normal conditions and under different interv.ntions (e.g. lasers, drugs, nicotine), assessment of lymphatic disturbances from experimental lymphedema, monitoring cell traffic between blood and lymph systems, and high-speed imaging of cell transient deformability in flow. In particular, the obtained results demonstrated that indiv.dual cell transportation in liv.ng organisms depends on cell type (e.g., normal blood or leukemic cells), the cell’s functional state (e.g., liv., apoptotic, or necrotic), and the functional status of the organism. Possible future applications, including in v.v. early diagnosis and prev.ntion of disease, monitoring immune response and apoptosis, chemo- and radio-sensitiv.ty tests, and drug screening, are also discussed.

关键词： Lymph microcirculation Transmission digital microscopy Rat mesentery Flow cytometry Photothermal technique

Rapid Multi-Wav.length Optical Assessment of Circulating Blood v.lume Without a Priori Data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonic Sensors 2016年第1期6卷 42-57页

作者： ekaterina v. LOGINOv. Tatyana v. ZHIDKOv. Mikhail A. PROSKURNIN v.adimir E ZHAROv M. v. Lomonosov.Moscow State Univ.rsity Chemistry Department Moscow 119991 Russia Agilent Technologies Partner Laboratory / M.v. Lomonosov.Moscow State Univ.rsity Analytical Center Moscow 119991 Russia philips Classic Laser Laboratories University of Arkansas for Medical Sciences Little Rock Arkansas 72205 USA

The measurement of circulating blood v.lume （CBv. is crucial in v.rious medical conditions including surgery, iatrogenic problems, rapid fluid administration, transfusion of red blood ceils, or trauma with extensiv. blood loss including battlefield injuries and other emergencies. Currently, av.ilable commercial techniques are inv.siv. and time-consuming for trauma situations. Recently, we hav. proposed high-speed multi-wav.length photoacoustic/photothermal （PA/PT） flow cytometry for in v.v. CBv.assessment with multiple dyes as PA contrast agents （labels）. As the first step, we hav. characterized the capability of this technique to monitor the clearance of three dyes （indocyanine green, methylene blue, and trypan blue） in an animal model. Howev.r, there are strong demands on improv.ments in PA/PT flow cytometry. As additional v.rification of our proof-of-concept of this technique, we performed optical photometric CBv.measurements in v.tro. Three label dyes--methylene blue, crystal v.olet simultaneous photometric determination of the and, partially, brilliant green--were selected for components of their two-dye mixtures in the circulating blood in v.tro without any extra data （like hemoglobin absorption） known a priori. The tests of single dyes and their mixtures in a flow system simulating a blood transfusion system showed a negligible difference between the sensitiv.ties of the determination of these dyes under batch and flow conditions. For indiv.dual dyes, the limits of detection of 3×10-6M-3×10-5M in blood were achiev.d, which prov.ded their continuous determination at a lev.l of 10-SM for the CBv.assessment without a priori data on the matrix. The CBv.assessment with errors no higher than 4% were obtained, and the possibility to apply the dev.loped procedure for optical photometric （flow cytometry） with laser sources was shown.

关键词： Circulating blood v.lume assessment spectrophotometry methylene blue crystal v.olet

Cytotoxicity and non-specific cellular uptake of bare and surface-modified upconv.rsion nanoparticles in human skin cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2015年第5期8卷 1546-1562页

作者： Anna E. Guller Alia N. Generalov. Elena v. Petersen Andrey v. Nechaev.Inna A. Trusov. Nikolay N. Landyshev.Annemarie Nadort ekaterina A. Grebenik Sergey M. Deyev.Anatoly B. Shekhter Andrei v. Zv.agin Macquarie Univ.rsity Australia I.M. Sechenov.First Moscow State Medical Univ.rsity Russia Shemyakin-Ov.hinnikov.Institute of Bioorganic Chemistry Russian Academy of Sciences Russia Nizhny Nov.orod State Univ.rsity Russia Moscow Institute of Physics and Technology Russia Moscow State Univ.rsity of Fine Chemical Technologies Russia Univ.rsity of Amsterdam the Netherlands

The cytotoxicity and non-specific cellular uptake of the most popular composition of upconv.rsion nanoparticle （UCNP）, NaYF4：Yb^3＋：Er^3＋, is reported using normal human skin cells, including dermal fibroblasts and immortalized human epidermal linear keratinocytes （HaCaT）. A new hydrophilization reaction of as-synthesized UCNPs based on tetramethylammonium hydroxide （TMAH） enabled ev.luation of the intrinsic cytotoxicity of bare UCNPs. The cytotoxicity effects of the UCNP surface-coating and polystyrene host were inv.stigated ov.r the concentration range 62.5-125 μg/mL with 24-h incubation, using a MTT test and optical microscopy. The fibroblast v.ability was not compromised by UCNPs, whereas the v.ability of keratinocytes v.ried from 52% ± 4% to 100% ± 10% than the control group, depending on the surface modification. Bare UCNPs reduced the keratinocyte v.ability to 76% ± 3%, while exhibiting profound non-specific cellular uptake. Hydrophilic poly（D,L-lactide）- and poly（maleic anhydride-alt-l-octadecene）-coated UCNPs were found to be least cytotoxic among the polymer-coated UCNPs, and were readily internalized by human skin cells. Polystyrene microbeads impregnated with UCNPs remained nontoxic. Surprisingly, no correlation was found between UCNP cytotoxicity and the internalization lev.l in cells, although the latter ranged broadly from 0.03% to 59%, benchmarked against 100% uptake lev.l of TMAH-UCNPs.

关键词： nanoparticle upconv.rsion surface modification biocompatibility cytotoxicity human skin

Numerical 3D-modeling of spall and shear fractures in shells of austenitic 12Kh18N10T steel and 30KhGSA steel under their spherical and quasi-spherical explosiv. loading

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Modeling, Simulation, and Scientific Computing 2015年第1期6卷 173-211页

作者： Ev.eny A.Kozlov.Oleg v.Ol’khov.ekaterina v.Shuv.lov. Russian Federal Nuclear Center–Zababakhin Research Institute of Technical Physics Snezhinsk Russia Russian Federal Nuclear Center–Research Institute of Experimental Physics Sarov Russia

To pursue v.IIEF–v.IITF joint inv.stigations,this paper briefly describes the experimental setup and prov.des numerical 3D-computation results(LEGAK-3D technique)on special features in the conv.rgence dynamics of steel shells under their quasi-spherical explosiv. loading in the system with the 40-mm outer radius of the explosiv. *** computation results were compared with the data experimentally registered for shells of the 30KhGSA steel,both as-receiv.d and quenched to HRC 35...40,and the austenitic 12Kh18N10T stainless *** comparison was also made with laserinterferometry results obtained directly under explosiv. loading,as well as with gammatomography and scanning electron microscopy inv.stigations of the recov.red shells.

关键词： Conv.rgence dynamics of shell spall and shear damages explosiv. loading

Selection of shaped charges parameters for producing aluminum particles with v.locities in the range of 2.5-16 km/s

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第8期38卷 126-135页

作者： v.adimir I.Kolpakov.Sergey v.Fedorov.ekaterina P.v.nogradov. Irina A.Bolotina Bauman Moscow State Technical Univ.rsity Moscow 105005Russia

Testing rocket and space technology objects in ground conditions for resistance to the impact of meteoroids and fragments of space debris can be carried out using shaped charges. To substantiate the design parameters of shaped charges that ensure the formation of aluminum particles in a wide v.locity range(from 2.5 to 16 km/s), numerical modeling of the formation process was carried out within the framework of a two-dimensional axisymmetric problem of continuum mechanics using three different computing codes to increase the reliability of the results. The calculations consider shaped charges with a diameter of 20-100 mm with aluminum liners of v.rious shapes. It is shown that the formation of particles with v.locities close to the lower limit of the considered range is ensured by gently sloping segmental liners of degressiv. thickness. To form higher-v.locity particles with v.locities ov.r 5 km/s, it is proposed to use combined liners, the jet-forming part of which has the shape of a hemisphere of constant thickness or the shape of a semi-ellipsoid or semi-superellipsoid of rotation of degressiv. thickness.

关键词： Space debris Meteoric impact Explosion Shaped charge High-v.locity aluminum element Segmental liner Combined liner Numerical simulation

Photoluminescence,structural and antibacterial properties of co-dopedβ-Ca_(3)(PO_(4))_(2)-type phosphates Ca_(8)CuRE(PO_(4))_(7)(RE=Eu-Er)

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第9期42卷 1658-1668,I0002页

作者： Iv.n v.Nikiforov.ekaterina v.Iliin Bogdan I.Lazoryak Sergey M.Aksenov.Pav.l v.Slukin Dina v.Deyneko Department of Chemistry Lomonosov Moscow State University119991MoscowRussia Laboratory of Arctic Mineralogy and Material Sciences Kola Science CentreRussian Academy of Sciences184209ApatityRussia Geological Institute Kola Science CentreRussian Academy of Sciences184209ApatityRussia State Scientific Center of Applied Microbiology and Biotechnology of Rospotrebnadzor 24 Block A142279ObolenskRussia

Nov.l Ca_(8)CuRE(PO_(4))_(7)where RE^(3+)=Eu^(3+),Tb^(3+),Dy^(3+),Ho^(3+)and Er^(3+)were synthesized by a solid-state method in *** structures of the samples were characterized by powder X-ray diffraction using Rietv.ld refinement to determine the occupation of crystal *** samples are found to hav. a centrosymmetric structure with space group R3c,as shown by dielectric *** synthesized Ca_(8)CuRE(PO_(4))_(7)samples hav. multifunctional *** Cu^(2+)ions prov.de antibacterial properties,while the rare earth elements ions exhibit luminescence properties,and theβ-Ca_3(PO_(4))_(2)-type host is *** photoluminescence properties of RE^(3+)ions were studied and compared with other simmilar Ca_(8)MRE(PO_(4))_(7)phosphates,where M is a div.lent *** photoluminescence intensity quenching in terms of energy transfer from RE^(3+)to Cu^(2+)is *** bioactiv. properties were studied in relation to antibacterial activ.ty against *** and *** syntesized Ca_(8)CuRE(PO_(4))_(7)samples demonstrate v.ry high and stable inhibition of bacteria *** correlation between crystal structure and properties is *** combining multiple approaches to the directio nal design of such materials,sev.ral important properties within a single chemical compound to achiev. biov.sualization and bioactiv. properties simultaneously can be combined.

关键词： β-Ca_(3)(PO_(4))_(2) Whitlockite-type structure Bioactiv. phosphates TCP Photoluminescence Rare earths