366 results match your criteria: "Institute of Russian Academy of Sciences[Affiliation]"
Phys Rev E
June 2018
Department of Physics, Moscow State University, Russia and IZMIRAN, Moscow, Russia.
We study average magnetic field growth in a mirror-symmetrical Kazantsev turbulent flow near the dissipative scales. Our main attention is directed to a subcritical regime, when an exponential decrease of magnetic energy is usually expected. We show that instead of damping, transient energy growth can be obtained, for example, in stochastic processes supported by the large-scale magnetic fields.
View Article and Find Full Text PDFPhys Rev Lett
June 2018
LPTMS, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Orsay 91405, France.
We examine stationary-state properties of an impurity particle injected into a one-dimensional quantum gas. We show that the value of the impurity's end velocity lies between zero and the speed of sound in the gas and is determined by the injection protocol. This way, the impurity's constant motion is a dynamically emergent phenomenon whose description goes beyond accounting for the kinematic constraints of the Landau approach to superfluidity.
View Article and Find Full Text PDFInt J Mol Sci
May 2018
Aix Marseille University, CNRS, LP3, 13288 Marseille, France.
Driven by surface cleanness and unique physical, optical and chemical properties, bare (ligand-free) laser-synthesized nanoparticles (NPs) are now in the focus of interest as promising materials for the development of advanced biomedical platforms related to biosensing, bioimaging and therapeutic drug delivery. We recently achieved significant progress in the synthesis of bare gold (Au) and silicon (Si) NPs and their testing in biomedical tasks, including cancer imaging and therapy, biofuel cells, etc. We also showed that these nanomaterials can be excellent candidates for tissue engineering applications.
View Article and Find Full Text PDFPlanta
August 2018
Royal Botanic Garden Edinburgh, 20a Inverleith Row, Edinburgh, EH3 5LR, UK.
The exceptionally complex exine of Echinops, representing a significant investment of energy, develops from an elaborate glycocalyx which establishes, by self-assembly, a multi-layered system of micelles upon which sporopollenin polymerizes. We report on pollen development in two species of Echinops (Asteraceae, Cynareae) studied using transmission and scanning electron microscopy with an emphasis on the organisation and development of the massive sporoderm (maximum thickness 18 μm). The major events of exine deposition during the tetrad stage follow the now familiar sequence of self-assembling micellar mesophases and the subsequent incorporation of sporopollenin, observed here as: (1) spherical units with light cores; (2) columns of spherical units with dark cores; (3) large branched macromolecules arranged in a dendritic, three-dimensional network of long alveoli; and (4) alveoli with electron-transparent cores and dense walls.
View Article and Find Full Text PDFSci Rep
February 2018
Faculty of Mathematics and Physics, Charles University, Prague, 12116, Czech Republic.
Rare-earth (R)-iron alloys are a backbone of permanent magnets. Recent increase in price of rare earths has pushed the industry to seek ways to reduce the R-content in the hard magnetic materials. For this reason strong magnets with the ThMn type of structure came into focus.
View Article and Find Full Text PDFMar Pollut Bull
January 2018
A.N. Severtsov Institute of Ecology and Evolution of Russian Academy of Sciences, 33 Leninsky prospekt, 119071 Moscow, Russian Federation.
We analyzed stable isotope composition of carbon and nitrogen of suspended organic matter (seston) and tissues of macroalgae, macroinvertebrates and fish from the coastal area of the highly eutrophic Neva Estuary to test a hypothesis that organic carbon of macroalgae Cladophora glomerata and Ulva intestinalis produced during green tides may be among primary sources supporting coastal food webs. The Stable Isotope Bayesian mixing model (SIAR) showed that consumers poorly use organic carbon produced by macroalgae. According to the results of SIAR modeling, benthic macroinvertebrates and fish mostly rely on pelagic derived carbon as a basal resource for their production.
View Article and Find Full Text PDFJ Biophotonics
July 2018
Aix-Marseille Univ, CNRS, Marseille, France.
The ability of noble metal-based nanoparticles (NPs) (Au, Ag) to drastically enhance Raman scattering from molecules placed near metal surface, termed as surface-enhanced Raman scattering (SERS), is widely used for identification of trace amounts of biological materials in biomedical, food safety and security applications. However, conventional NPs synthesized by colloidal chemistry are typically contaminated by nonbiocompatible by-products (surfactants, anions), which can have negative impacts on many live objects under examination (cells, bacteria) and thus decrease the precision of bioidentification. In this article, we explore novel ultrapure laser-synthesized Au-based nanomaterials, including Au NPs and AuSi hybrid nanostructures, as mobile SERS probes in tasks of bacteria detection.
View Article and Find Full Text PDFComp Cytogenet
November 2017
Department of Karyosystematics, Zoological Institute of Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia.
DNA barcoding has been suggested as a universal tool for molecular species identification; however, it cannot be applied in cases when morphologically similar species share their DNA barcodes due to the common ancestry or mitochondrial introgression. Here we analyze the karyotype of Polyommatus (Agrodiaetus) morgani (Le Cerf, 1909) from the region of its type locality in the southern Zagros Mountains in Iran, provide first chromosomal evidence for P. (A.
View Article and Find Full Text PDFPhys Rev Lett
November 2017
Instituut-Lorentz, Universiteit Leiden, P.O. Box 9506, 2300 RA Leiden, The Netherlands.
The adiabatic theorem is a fundamental result in quantum mechanics, which states that a system can be kept arbitrarily close to the instantaneous ground state of its Hamiltonian if the latter varies in time slowly enough. The theorem has an impressive record of applications ranging from foundations of quantum field theory to computational molecular dynamics. In light of this success it is remarkable that a practicable quantitative understanding of what "slowly enough" means is limited to a modest set of systems mostly having a small Hilbert space.
View Article and Find Full Text PDFCurr Biol
November 2017
Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Box 50007, 10405 Stockholm, Sweden. Electronic address:
While present-day taxa are valuable proxies for understanding the biology of extinct species, it is also crucial to examine physical remains in order to obtain a more comprehensive view of their behavior, social structure, and life histories [1, 2]. For example, information on demographic parameters such as age distribution and sex ratios in fossil assemblages can be used to accurately infer socioecological patterns (e.g.
View Article and Find Full Text PDFAnal Chim Acta
October 2017
Institute of Analytical and Bioanalytical Chemistry, Ulm University, 89081 Ulm, Germany. Electronic address:
Plasmonic anisotropic nanoparticles possess a number of hot spots on their surface due to the presence of sharp edges, tips or vertices, leading to a high electric field strength surrounding the nanostructures. In this paper, we explore different plasmonic nanostructures, including anisotropic gold nanostars (AuNSts) and spherical gold nanoparticles, in surface-enhanced infrared absorption spectroscopy (SEIRAS) in an attenuated total reflection (ATR) configuration. In our experiments, we observed up to 10-times enhancement of the infrared (IR) absorption of thioglycolic acid (TGA) and up to 2-times enhancement of signals for bovine serum albumin (BSA) protein on plasmonic nanostructure-based films deposited on a silicon (Si) internal reflection element (IRE) compared to bare Si IRE.
View Article and Find Full Text PDFProg Biophys Mol Biol
December 2017
Mechanical Engineering Research Institute of Russian Academy of Sciences, Malyi Kharitonievsky Pereulok, 4, Moscow, 101990, Russia.
The ancient Chinese book I-Ching was written a few thousand years ago. It introduces the system of symbols Yin and Yang (equivalents of 0 and 1). It had a powerful impact on culture, medicine and science of ancient China and several other countries.
View Article and Find Full Text PDFSensors (Basel)
August 2017
Art Photonics GmbH, Rudower Chaussee 46, 12489 Berlin, Germany.
Optical spectroscopy is increasingly used for cancer diagnostics. Tumor detection feasibility in human kidney samples using mid- and near-infrared (NIR) spectroscopy, fluorescence spectroscopy, and Raman spectroscopy has been reported (Artyushenko et al., Spectral fiber sensors for cancer diagnostics in vitro.
View Article and Find Full Text PDFSci Rep
August 2017
Department of Karyosystematics, Zoological Institute of Russian Academy of Sciences, Universitetskaya nab. 1, 199034, St. Petersburg, Russia.
Despite predictions of the classic, hybrid-sterility model of chromosomal speciation, some organisms demonstrate high rate of karyotype evolution. This rate is especially impressive in Agrodiaetus butterflies that rapidly evolved the greatest chromosome number diversity known in animal kingdom within a single subgenus. Here we analyzed karyotype evolution in Agrodiaetus using phylogenetic comparative methods.
View Article and Find Full Text PDFMany systems found in nature are susceptible to tipping, where they can shift from one stable dynamical state to another. This shift in dynamics can be unfavorable in systems found in various fields ranging from ecology to finance. Hence, it is important to identify the factors that can lead to tipping in a physical system.
View Article and Find Full Text PDFPhys Rev E
June 2017
Department of Physics, University of Oslo, 0316 Oslo, Norway.
In any general cycle of measurement, feedback, and erasure, the measurement will reduce the entropy of the system when information about the state is obtained, while erasure, according to Landauer's principle, is accompanied by a corresponding increase in entropy due to the compression of logical and physical phase space. The total process can in principle be fully reversible. A measurement error reduces the information obtained and the entropy decrease in the system.
View Article and Find Full Text PDFJ Biol Regul Homeost Agents
August 2017
Scientific Center of Childrens Health, Moscow, Russian Federation.
We discuss the physical mechanisms of microwave heating of milk and infant formulas, and possible causes of nutrient degradation and scalds of infants reported in a number of papers. We list the advantages of microwave heating, formulate criteria of safe heating, and discuss discrepancies between different papers. A novel technique of microwave heating which prevents scalds and saves nutrients is reported.
View Article and Find Full Text PDFSci Technol Adv Mater
May 2017
Divisions of Solid State Physics and Physics of Dielectrics and Semiconductors, Ioffe Physical-Technical Institute of Russian Academy of Sciences, St Petersburg, Russia.
Thin (4-20 nm) yttrium iron garnet (YFeO, YIG) layers have been grown on gadolinium gallium garnet (GdGaO, GGG) 111-oriented substrates by laser molecular beam epitaxy in 700-1000 °C growth temperature range. The layers were found to have atomically flat step-and-terrace surface morphology with step height of 1.8 Å characteristic for YIG(111) surface.
View Article and Find Full Text PDFProtoplasma
January 2018
Komarov Botanical Institute of Russian Academy of Sciences, Popov St. 2, 197376, St. Petersburg, Russia.
By a detailed ontogenetic study of Polemonium caeruleum pollen, tracing each stage of development at high TEM resolution, we aim to understand the establishment of the pollen wall and to unravel the mechanisms underlying sporoderm development. The main steps of exine ontogeny in Polemonium caeruleum, observed in the microspore periplasmic space, are spherical units, gradually transforming into columns, then to rod-like units (procolumellae), the appearance of the initial tectum, growth of columellae in height and tectum in thickness and initial sporopollenin accumulation on them, the appearance of the endexine lamellae and of dark-contrasted particles on the tectum, the appearance of a sponge-like layer and of the intine in aperture sites, the appearance of the foot layer on the base of the sponge-like layer and of spinules on the tectum, and massive sporopollenin accumulation. This sequence of developmental events fits well to the sequence of self-assembling micellar mesophases.
View Article and Find Full Text PDFSci Total Environ
December 2017
Atlantic Branch of P.P. Shirshov Institute of Oceanology of Russian Academy of Sciences, Prospect Mira, 1, Kaliningrad 236022, Russia.
Distribution of microplastics particles (MPs) in the water column is investigated on the base of 95 water samples collected from various depths in the Baltic Sea Proper in 2015-2016. Fibres are the prevalent type of MPs: 7% of the samples contained small films; about 40% had (presumably) paint flakes, while 63% contained coloured fibres in concentrations from 0.07 to 2.
View Article and Find Full Text PDFPlanta
September 2017
Komarov Botanical Institute of Russian Academy of Sciences, Popov St. 2, St. Petersburg, 197376, Russia.
Our findings suggest a new approach to pollen ontogenetic investigations, entailing consideration of physical factors, which enable a better understanding of exine developmental processes. The sporopollenin-containing part of the pollen wall-the exine-is one of the most complex cell walls in plants. By tracing each stage of microspore development in Larix decidua with TEM, we aimed to understand the underlying mechanisms of its exine establishment.
View Article and Find Full Text PDFJ Am Chem Soc
April 2017
School of Physical Sciences, University of Kent, Canterbury, Kent CT2 7NH, U.K.
Ionic conductivity is ubiquitous to many industrially important applications such as fuel cells, batteries, sensors, and catalysis. Tunable conductivity in these systems is therefore key to their commercial viability. Here, we show that geometric frustration can be exploited as a vehicle for conductivity tuning.
View Article and Find Full Text PDFJ Biomed Opt
March 2017
General Physics Institute of Russian Academy of Sciences, Moscow, RussiacNational Research Nuclear University MEPhI, Laboratory of Laser Thermonuclear Fusion, Moscow, Russia.
The optical properties of different cow and pig biological tissues such as skeletal muscle, adipose, spinal cord, and dura mater of the spinal cord were investigated in the spectral range of 350 to 2600 nm. The measurements were carried out by a commercially available spectrophotometer SHIMADZU UV 3101PC. The wavelength dependence on the scattering coefficient has been observed to follow a power-law decay for skeletal muscle and dura mater of spinal cord.
View Article and Find Full Text PDFChemphyschem
May 2017
Aix-Marseille University, CNRS, UMR 7341 CNRS, LP3, Campus de Luminy, Case 917, 13288, Marseille Cedex 9, France.
Continuous wave (CW) radiation from a Yb-fiber laser (central wavelength 1064 nm, power 1-200 W) was used to initiate ablation of a gold target in deionized water and to synthesize bare (unprotected) gold nanoparticles. We show that the formed nanoparticles present a single low-size-dispersed population with a mean size of the order of 10 nm, which contrasts with previously reported data on dual populations of nanoparticles formed during pulsed laser ablation in liquids. The lack of a second population of nanoparticles is explained by the absence of cavitation-related mechanism of material ablation, which typically takes place under pulsed laser action on a solid target in liquid ambience, and this supposition is confirmed by plume visualization tests.
View Article and Find Full Text PDFJ Exp Biol
April 2017
Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven D-27570, Germany.
According to the membrane pacemaker theory of metabolism (MPT), allometric scaling of metabolic rate in animals is determined by the composition of cellular and mitochondrial membranes, which changes with body size in a predictable manner. MPT has been elaborated from interspecific comparisons in mammals. It projects that the degree of unsaturation of membrane phospholipids decreases in larger organisms, thereby lowering ion permeability of the membranes and making cellular, and thus whole-animal metabolism more efficient.
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