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181.
Michail Zak 《International Journal of Non》1985,20(4):297-308
Two types of chaos are associated with the Hadamard and Liapunov instabilities, respectively. Their criteria and peculiarities are analyzed. 相似文献
182.
We study the exponential growth of the codimensions cn(L) of a finite-dimensional Lie algebra L over a field of characteristic zero. We show that if the solvable radical of L is nilpotent then
exists and is an integer. 相似文献
183.
Elena Eremeeva Dr. Michail Abramov Lia Margamuljana Prof. Jef Rozenski Dr. Valerie Pezo Dr. Philippe Marlière Prof. Piet Herdewijn 《Angewandte Chemie (International ed. in English)》2016,55(26):7515-7519
The ability of alternative nucleic acids, in which all four nucleobases are substituted, to replicate in vitro and to serve as genetic templates in vivo was evaluated. A nucleotide triphosphate set of 5‐chloro‐2′‐deoxyuridine, 7‐deaza‐2′‐deoxyadenosine, 5‐fluoro‐2′‐deoxycytidine, and 7‐deaza‐2′deoxyguanosine successfully underwent polymerase chain reaction (PCR) amplification using templates of different lengths (57 or 525mer) and Taq or Vent (exo‐) DNA polymerases as catalysts. Furthermore, a fully morphed gene encoding a dihydrofolate reductase was generated by PCR using these fully substituted nucleotides and was shown to transform and confer trimethoprim resistance to E. coli. These results demonstrated that fully modified templates were accurately read by the bacterial replication machinery and provide the first example of a long fully modified DNA molecule being functional in vivo. 相似文献
184.
Michail N. Elinson Alexey I. Ilovaisky Valentina M. Merkulova Nikita O. Stepanov Fedor M. Miloserdov Yuri N. Ogibin Gennady I. Nikishin 《Tetrahedron》2007,63(42):10543-10548
An electrochemically induced catalytic multicomponent transformation of cyclic 1,3-diketones, isatins, and malononitrile in alcohols in an undivided cell in the presence of sodium bromide as an electrolyte results in the formation of spirooxindoles with fused functionalized 5,6,7,8-tetrahydro-4H-chromene system in 83-98% yields. The application of this efficient electrocatalytic method to the formation of medicinally relevant spirocyclic (4H-chromene)-4,3′-oxindoles is beneficial from the viewpoint of diversity-oriented large-scale processes and represents novel, facile, and environmentally benign synthetic concept for multicomponent reaction strategy. 相似文献
185.
Doz. Dr. Janko Dimitriev Michail Arnaudov Vesselin Dimitrov 《Monatshefte für Chemie / Chemical Monthly》1976,107(6):1335-1343
Studies of glasses and their crystalline products in the TeO2–V2O5 system were made in the 1400–400 cm–1 range. A continuous shift of the V=O-band from 1020 cm–1 to 940 cm–1 was found in the glasses with decreasing concentration of V2O5, as well as a sharp decrease in the intensity at 830 cm–1. On the basis of the results obtained, it is concluded that with increasing TeO2 content, the structure of the glasses is changed, caused by the breaking of the V–O–V bonds and the formation of Te–O–Te bridges.The IR-spectrum of the 2TeO2·V2O5 compound in both crystalline and vitreous states was studied for the first time. The behaviour of the absorption bands is related to the structure of the glasses studied.
Mit 4 Abbildungen 相似文献
Mit 4 Abbildungen 相似文献
186.
Michail N. Elinson Sergey K. Feducovich Anatolii N. Vereshchagin Sergey V. Gorbunov Pavel A. Belyakov Gennady I. Nikishin 《Tetrahedron letters》2006,47(51):9129-9133
Electrolysis of an aldehyde, malononitrile and a malonate in an alcohol in an undivided cell in the presence of sodium acetate-sodium halide as a double mediatory system results in the formation of 3-substituted-2,2-dicyanocyclopropane-1,1-dicarboxylates in 40-60% yields. 相似文献
187.
Alexander S GolubevPavel V Pasternak Alexander F ShidlovskiiLjudmila N Savelèva Boris B AverkievVladimir N Nesterov Michail Yu AntipinAlexander S Peregudov Nikolai D Chkanikov 《Journal of fluorine chemistry》2002,114(1):63-74
New CF2X-analogues of 1,1-dicyano-2,2-bis(trifluoromethyl)ethylene (1) (X=H, Cl) were synthesised by the condensation of polyfluoroketones with malononitrile followed by dehydration using thionyl chloride (or phosphorus pentoxide). The heterocyclisation reactions of new CF2X-analogues of 1,1-dicyano-2,2-bis(trifluoromethyl)ethylene with amidines, 5-aminopyrazoles and 3-methyl-2-pyrazolin-5-ones were systematically investigated. 相似文献
188.
Astrocytes, a special type of glial cells, were considered to have just a supporting role in information processing in the brain. However, several recent studies have shown that they can be chemically stimulated by various neurotransmitters, such as ATP, and can generate Ca2+ and ATP waves, which can propagate over many cell lengths before being blocked. Although pathological conditions, such as spreading depression and epilepsy, have been linked to abnormal wave propagation in astrocytic cellular networks, a quantitative understanding of the underlying characteristics is still lacking. Astrocytic cellular networks are inhomogeneous, in the sense that the domain they occupy contains passive regions or gaps, which are unable to support wave propagation. Thus, this work focuses on understanding the complex interplay between single-cell signal transduction, domain inhomogeneity, and the characteristics of wave propagation and blocking in astrocytic cellular networks. The single-cell signal transduction model that was employed accounts for ATP-mediated IP3 production, the subsequent Ca2+ release from the ER, and ATP release into the extracellular space. The model is excitable and thus an infinite range of wave propagation is observed if the domain of propagation is homogeneous. This is not always the case for inhomogeneous domains. To model wave propagation in inhomogeneous astrocytic networks, a reaction-diffusion framework was developed and one-gap as well as multiple-gap cases were simulated using an efficient finite-element algorithm. The minimum gap length that blocks the wave was computed as a function of excitability levels and geometric characteristics of the inhomogeneous network, such as the length of the active regions (cells). Complex transient patterns, such as wave reflection, wave trapping, and generation of echo waves, were also predicted by the model, and their relationship to the geometric characteristics of the network was evaluated. Therefore, the proposed model can help in the formulation of testable hypotheses to explain the observed abnormal wave propagation in pathological situations. 相似文献
189.
Dr. Goutam Kumar Kole Marta Košćak Dr. Anissa Amar Dr. Dragomira Majhen Dr. Ksenija Božinović Dr. Zlatko Brkljaca Dr. Matthias Ferger Dr. Evripidis Michail Sabine Lorenzen Dr. Alexandra Friedrich Dr. Ivo Krummenacher Michael Moos Prof. Dr. Holger Braunschweig Prof. Dr. Abdou Boucekkine Prof. Dr. Christoph Lambert Prof. Dr. Jean-François Halet Prof. Dr. Ivo Piantanida Prof. Dr. Klaus Müller-Buschbaum Prof. Dr. Todd B. Marder 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(40):e202200753
A series of bis-(4’-pyridylethynyl)arenes (arene=benzene, tetrafluorobenzene, and anthracene) were synthesized and their bis-N-methylpyridinium compounds were investigated as a class of π-extended methyl viologens. Their structures were determined by single crystal X-ray diffraction, and their photophysical and electrochemical properties (cyclic voltammetry), as well as their interactions with DNA/RNA were investigated. The dications showed bathochromic shifts in emission compared to the neutral compounds. The neutral compounds showed very small Stokes shifts, which are a little larger for the dications. All of the compounds showed very short fluorescence lifetimes (<4 ns). The neutral compound with an anthracene core has a quantum yield of almost unity. With stronger acceptors, the analogous bis-N-methylpyridinium compound showed a larger two-photon absorption cross-section than its neutral precursor. All of the dicationic compounds interact with DNA/RNA; while the compounds with benzene and tetrafluorobenzene cores bind in the grooves, the one with an anthracene core intercalates as a consequence of its large, condensed aromatic linker moiety, and it aggregates within the polynucleotide when in excess over DNA/RNA. Moreover, all cationic compounds showed highly specific CD spectra upon binding to ds-DNA/RNA, attributed to the rare case of forcing the planar, achiral molecule into a chiral rotamer, and negligible toxicity toward human cell lines at ≤10 μM concentrations. The anthracene-analogue exhibited intracellular accumulation within lysosomes, preventing its interaction with cellular DNA/RNA. However, cytotoxicity was evident at 1 μM concentration upon exposure to light, due to singlet oxygen generation within cells. These multi-faceted features, in combination with its two-photon absorption properties, suggest it to be a promising lead compound for development of novel light-activated theranostic agents. 相似文献
190.
Michail Nedyalkov Caroline Sultanem Jean-Jacque Benattar 《Central European Journal of Chemistry》2007,5(3):748-765
The contact angles of protein Newton black foam films from ALG (alpha-lactalbumin), BLG (beta-lactoglobulin) and BSA (bovine
serum albumin) are measured here within. The measurements are carried out under dynamic and equilibrium conditions. For all
proteins, a strong hystheresis effect of the contact angle is observed under dynamic conditions. An attempt is made to explain
these results by the slow adsorption and desorption kinetics of the protein bilayers and by the dynamic structure and the
rheology of the protein network forming the bubble walls.
In addition, we propose a modification of the experimental device reported previously for contact angle measurements of large
flat films in equilibrium. The advantages of this method are discussed in detail. Some shortcomings (precision, reproducibility)
of this preliminary variant of the device in this initial stage of its application, do not allow one to draw reliable conclusions about the interactions
of these films. Some improvements of the measurement quality are proposed.
相似文献