排序方式: 共有43条查询结果,搜索用时 15 毫秒
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Jeremy D. Mirza Álvaro E. Migotto Ilia V. Yampolsky Gabriela V. de Moraes Aleksandra S. Tsarkova Anderson G. Oliveira 《Photochemistry and photobiology》2020,96(4):768-778
Chaetopterus variopedatus has been studied for over a century in terms of its physiology, ecology and life history. One focus of research is on its intrinsic bioluminescent emissions, which can be observed as a blue light emitted from the extremities of individual body segments, or as a secreted mucus. Even though research shows that C. variopedatus is a species complex miscategorized as a single species, all of the variants of this polychaete produce light, which has been investigated in terms of both physiology and biochemistry. Despite decades of study, there are still many questions about the luminescence reaction, and, as of yet, no clear function for light emission exists. This review summarizes the current knowledge on C. variopedatus luminescence in addition to briefly describing its morphology, life cycle and ecology. Possible functions for luminescence were discussed using observations of specimens found in Brazil, along with a comparison of previous studies of other luminescent organisms. Further study will provide a better understanding of how and why C. variopedatus produces luminescence, and purifying the protein and luciferin involved could lead to new bioanalytical applications, as this reaction is unique among all known luminescent systems. 相似文献
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O. G. Tsarkova 《Physics of Wave Phenomena》2007,15(1):12-45
A complex optical method for simultaneous determination of optical and thermal properties of solids (true temperature, reflectance,
transmittance, absorbance, extinction, specific heat capacity, thermal conductivity, and diffusivity) in a wide temperature
range (800–2700°C) was proposed and experimentally demonstrated. The developed setup is characterized by a high processing
rate (the time taken for measuring all parameters is from milliseconds to tens of seconds). It allows the study of rather
small samples (about several milligrams), which is a significant advantage as applied to new or expensive materials. New and
widely used materials (AlN, Al2O3, Si3N4, SiC, and Al2O3/SiC ceramics; C45, 16MnCrS5, 115CrV3, X5NiCr18 9, X12CrNi17 7, Sd, and Satellite 6 steels; E-Cu, CuSn, AlMgSi1, and AlCuMgPb
copper and aluminum alloys; as well as chemical vapor deposition (CVD) diamond films) were studied at heating rates of 103−104K·s−1 in various atmospheres (air and argon at pressures of 1 and 10−3 atm). This study demonstrated high efficiency and informativity of the proposed method. The data obtained can be used to
develop theoretical models describing the solid structure and properties at high temperatures in oxidizing, neutral, or regenerative
atmospheres. 相似文献
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<正>Two new eudesmane derivatives were isolated from the leaves and flowers of Verbesina virginica,along with the known 6-O-β-E -p-coumaroyl-4α-hydroxyeudesmane(1).Their structures were determined as 6-O-β-Z-p-coumaroyl-4α-hydroxyeudesmane(2) and 6-O-α-E-p-coumaroyl-1β-4α-dihydroxyeudesmane(3) by spectroscopic methods. 相似文献
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Novel Mechanism of Bioluminescence: Oxidative Decarboxylation of a Moiety Adjacent to the Light Emitter of Fridericia Luciferin
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Maxim A. Dubinnyi Zinaida M. Kaskova Natalja S. Rodionova Mikhail S. Baranov Andrey Yu. Gorokhovatsky Alexey Kotlobay Kyril M. Solntsev Aleksandra S. Tsarkova Valentin N. Petushkov Ilia V. Yampolsky 《Angewandte Chemie (International ed. in English)》2015,54(24):7065-7067
A novel luciferin from a bioluminescent Siberian earthworm Fridericia heliota was recently described. In this study, the Fridericia oxyluciferin was isolated and its structure elucidated. The results provide insight into a novel bioluminescence mechanism in nature. Oxidative decarboxylation of a lysine fragment of the luciferin supplies energy for light generation, while a fluorescent CompX moiety remains intact and serves as the light emitter. 相似文献
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CM Thaker S Rayaprol Krushna Mavani DS Rana MS Sahasrabudhe SI Patil DG Kuberkar 《Pramana》2002,58(5-6):1035-1039
The effect of simultaneous substitution of a fluctuating cation and a divalent cation in LaMnO3 perovskite modifies the properties of the material to exhibit large valence colossal magnetoresistance (CMR) effect. A good
example of these properties is (La1−2x
Pr
x
Ca
x
)MnO3 (LPCMO) type CMR material. In this communication it is reported that, with the increase in x (for x=0.1, 0.15, 0.2), the T
c varies between 100 and 120 K with improvisation in metal-insulator transition. Interestingly, resistance increases with x from few hundred ohms to few kilo ohms with corresponding decrease in the unit cell volume. The results of the studies using
X-ray diffraction (XRD), electrical resistivity, magnetoresistance and ac susceptibility measurements on LPCMO samples for
understanding the structural, transport and magnetic properties are discussed in detail. 相似文献
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John W.Grove 《数学物理学报(B辑英文版)》2010,30(2):563-594
This article describes mathematical models for phase separated mixtures of materials that are in pressure and velocity equilibrium but not necessarily temperature equilibrium. General conditions for constitutive models for such mixtures that exhibit a single mixture sound speed are discussed and specific examples are described. 相似文献
8.
Enzyme‐Compatible Dynamic Nanoreactors from Electrostatically Bridged Like‐Charged Surfactants and Polyelectrolytes
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Isabell Hofmann Melanie König Dr. Carlos G. Lopez Dr. Ljubica Vojcic Prof. Dr. Walter Richtering Prof. Dr. Ulrich Schwaneberg Dr. Larisa A. Tsarkova 《Angewandte Chemie (International ed. in English)》2018,57(30):9402-9407
Reported is an unanticipated mechanism of attractive electrostatic interactions of fully neutralized polyacrylic acid (PAA) with like‐charged surfactants. Amphiphilic polymer‐surfactant complexes with high interfacial activity and a solubilization capacity exceeding that of conventional micelles are formed by bridging with Ca2+ ions. Incorporation of a protease into such dynamic nanoreactors results in a synergistically enhanced cleaning performance because of the improved solubilization of poorly water‐soluble immobilized proteins. Competitive interfacial and intermolecular interactions on different time‐ and length‐scales have been resolved using colorimetric analysis, dynamic tensiometry, light scattering, and molecular dynamic simulations. The discovered bridging association mechanism suggests reengineering of surfactant/polymer/enzyme formulations of modern detergents and opens new opportunities in advancing labile delivery systems. 相似文献
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Mikhail V. Dubovis Gennady F. Rudakov Alexander S. Kulagin Kseniya V. Tsarkova Sergey V. Popkov Alexander S. Goloveshkin Georgiy V. Cherkaev 《Tetrahedron》2018,74(6):672-683
Based on the deoxygenation reaction of 1-(1-tert-butyl-3-nitroazetidine-3-yl)-1H-1,2,3-triazoles a new method for the synthesis of substituted 1-(1H-imidazole-4-yl)-1H-1,2,3-triazoles has been developed. Fungicidal activity of these compounds has been investigated at a range of phytopathogenic fungi. 相似文献
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I.?S.?Zaitsev M.?S.?Tsarkova D.?O.?Solovyeva S.?Yu.?ZaitsevEmail author 《Moscow University Chemistry Bulletin》2018,73(6):307-311
The use of the achievements attained in colloid chemistry and other fields of chemical sciences allows us to develop new nanoscale systems for chemosensorics. Mixed monolayers consisting of a new chemosensory amphiphilic dithia-18-crown-6, which contains a dye of 4-alkylpyridine series with polyvinyl stearate at the water–air interface, are obtained and studied. The influence of various concentrations of silver ions on these mixed monolayers is studied. A promising method for the detection of silver ions in water using the given nanoscale systems based on chemosensory amphiphilic dithia-18-crown-6 is proposed. 相似文献