A novel long non-coding natural antisense RNA is a negative regulator of Nos1 gene expression

Long non-coding natural antisense transcripts (NATs) are widespread in eukaryotic species. Although recent studies indicate that long NATs are engaged in the regulation of gene expression, the precise functional roles of the vast majority of them are unknown. Here we report that a long NAT (Mm-antiNos1 RNA) complementary to mRNA encoding the neuronal isoform of nitric oxide synthase (Nos1) is expressed in the mouse brain and is transcribed from the non-template strand of the Nos1 locus. Nos1 produces nitric oxide (NO), a major signaling molecule in the CNS implicated in many important functions including neuronal differentiation and memory formation. We show that the newly discovered NAT negatively regulates Nos1 gene expression. Moreover, our quantitative studies of the temporal expression profiles of Mm-antiNos1 RNA in the mouse brain during embryonic development and postnatal life indicate that it may be involved in the regulation of NO-dependent neurogenesis

Landau damping in thin films irradiated by a strong laser field

The rate of linear collisionless damping (Landau damping) in a classical electron gas confined to a heated ionized thin film is calculated. The general expression for the imaginary part of the dielectric tensor in terms of the parameters of the single-particle self-consistent electron potential is obtained. For the case of a deep rectangular well, it is explicitly calculated as a function of the electron temperature in the two limiting cases of specular and diffuse reflection of the electrons from the boundary of the self-consistent potential. For realistic experimental parameters, the contribution of Landau damping to the heating of the electron subsystem is estimated. It is shown that for films with a thickness below about 100 nm and for moderate laser intensities it may be comparable with or even dominate over electron-ion collisions and inner ionization.Comment: 15 pages, 2 figure

Electron-phonon scattering at the intersection of two Landau levels

We predict a double-resonant feature in the magnetic field dependence of the phonon-mediated longitudinal conductivity $\sigma_{xx}$ of a two-subband quasi-two-dimensional electron system in a quantizing magnetic field. The two sharp peaks in $\sigma_{xx}$ appear when the energy separation between two Landau levels belonging to different size-quantization subbands is favorable for acoustic-phonon transitions. One-phonon and two-phonon mechanisms of electron conductivity are calculated and mutually compared. The phonon-mediated interaction between the intersecting Landau levels is considered and no avoided crossing is found at thermal equilibrium.Comment: 13 pages, 8 figure

Three-loop verification of a new algorithm for the calculation of a β\beta-function in supersymmetric theories regularized by higher derivatives for the case of N=1{\cal N}=1 SQED

We verify a recently proposed method for obtaining a $\beta$-function of ${\cal N}=1$ supersymmetric gauge theories regularized by higher derivatives by an explicit calculation. According to this method, a $\beta$-function can be found by calculating specially modified vacuum supergraphs instead of a much larger number of the two-point superdiagrams. The result is produced in the form of a certain integral of double total derivatives with respect to the loop momenta. Here we compare the results obtained for the three-loop $\beta$-function of ${\cal N}=1$ SQED in the general $\xi$-gauge with the help of this method and with the help of the standard calculation. Their coincidence confirms the correctness of the new method and the general argumentation used for its derivation. Also we verify that in the considered approximation the NSVZ relation is valid for the renormalization group functions defined in terms of the bare coupling constant and for the ones defined in terms of the renormalized coupling constant in the HD+MSL scheme, both its sides being gauge-independent.Comment: 19 pages, 8 figures; title changed, minor corrections; the final version to appear in Nuclear Physics

"Cold Melting" of Invar Alloys

An anomalously strong volume magnetostriction in Invars may lead to a situation when at low temperatures the dislocation free energy becomes negative and a multiple generation of dislocations becomes possible. This generation induces a first order phase transition from the FCC crystalline to an amorphous state, and may be called "cold melting". The possibility of the cold melting in Invars is connected with the fact that the exchange energy contribution into the dislocation self energy in Invars is strongly enhanced, as compared to conventional ferromagnetics, due to anomalously strong volume magnetostriction. The possible candidate, where this effect can be observed, is a FePt disordered Invar alloy in which the volume magnetostriction is especially large

Melting Point and Lattice Parameter Shifts in Supported Metal Nanoclusters

The dependencies of the melting point and the lattice parameter of supported metal nanoclusters as functions of clusters height are theoretically investigated in the framework of the uniform approach. The vacancy mechanism describing the melting point and the lattice parameter shifts in nanoclusters with decrease of their size is proposed. It is shown that under the high vacuum conditions (p<10^-7 torr) the essential role in clusters melting point and lattice parameter shifts is played by the van der Waals forces of cluster-substrate interation. The proposed model satisfactorily accounts for the experimental data.Comment: 6 pages, 3 figures, 1 tabl

Bi(iii) immobilization inside MIL-101: enhanced photocatalytic performance

© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.A novel hybrid material Bi(iii)@MIL-101 (Bi(iii) = Bi-containing oxoclusters and MIL-101 = chromium(iii) oxoterephthalate) was obtained by the intra-pore hydrolysis of guest bismuth(iii) chloride in ammonia solution. This compound was characterized by chemical analysis, powder X-ray diffraction, nitrogen sorption and TEM techniques. According to the obtained data all Bi species are located only inside the matrix. The framework structure remains intact during all synthetic operations. The chemical nature of Bi(iii)-containing clusters inside the MIL-101 matrix was suggested based on the EXAFS study. The catalytic activity of Bi(iii)@MIL-101 in photodegradation of methyl red (MR) has been tested. The introduction of Bi(iii)-species inside MIL-101 significantly increases the photocatalytic performance in comparison with layered BiOCl which was obtained under the same synthetic conditions without MIL-101

Трансформации формильных предшественников 3,7-интерфениленовых 11-дезоксипростаноидов в кислой среде

It has been shown that the formyl precursors of 3,7-interphenylene 11-deoxyprostanoids, formed during acidic hydrolysis of the corresponding acetals, can undergo isomerization (disproportionation) in the acidic medium to give 2-(arylalkyl)-3-(hydroxymethyl)cyclopent-2-ene-1-ones – the synthons for prostanoids and phytoprostanes of the series B. Acetal precursors of 3,7-interphenylene 11-deoxyprostaglandin analogues with electron-donating alkoxy substituent in position 3′ of the aromatic fragment in the α-chain under similar conditions hydrolyze with the formation of formyl derivatives that spontaneously cyclize to produce 2,3,4,9-tetrahydro-1H-cyclopenta[b]naphthalene-1-ones.Показано, что формильные предшественники 3,7-интерфениленовых 11-дезоксипростаноидов, образующиеся при кислотном гидролизе соответствующих ацеталей, в кислой среде могут претерпевать изомеризацию (диспропорционирование) с образованием 2-(арилалкил)-3-(гидроксиметил)циклопент-2-ен-1-онов – синтонов для простаноидов и фитопростанов серии В. При наличии же электронодонорного алкоксильного заместителя в положении 3′ ароматического фрагмента α-цепи ацетальных предшественников 3,7-интерфениленовых 11-дезоксианалогов простагландинов образующиеся на их основе формилпроизводные в аналогичных условиях спонтанно циклизуются с образованием 2,3,4,9-тетрагидро-1Н-циклопента[b]нафтален-1-онов

Синтоны для новых 11-дезокси-3-окса-3,7-интер-м-фениленовых аналогов простагландинов

A synthetic scheme for obtaining cyclopentenone synthons for metabolically stable 11-deoxy-3-oxa-3,7-inter-m-phenylene prostaglandin analogues has been developed. The key step of the scheme is the Knoevenagel condensation of cyclopentane-1,3-dione with the readily available 3-(formylphenoxy)acetic acid methyl ester in the presence of Hantzsh ester.Разработана схема синтеза циклопентеноновых синтонов для метаболически стабильных 11-де з-окси-3-окса-3,7-интер-м-фениленовых аналогов простагландинов. Ключевой стадией схемы является конденсация циклопентан-1,3-диона с легко доступным метиловым эфиром 3-(формилфенокси)уксусной кислоты по Кневенагелю в присутствии эфира Ганча