Indirect Optical Absorption of Single Crystalline beta-FeSi2

We investigated optical absorption spectra near the fundamental absorption edge of beta-FeSi2 single crystals by transmission measurements. The phonon structure corresponding to the emission and absorption component was clearly observed in the low-temperature absorption spectra. Assuming exciton state in the indirect allowed transition, we determined a phonon energy of 0.031 +- 0.004 eV. A value of 0.814 eV was obtained for the exciton transition energy at 4K.Comment: 10 pages with 3 figure

A new era for functional labeling of neurons: activity-dependent promoters have come of age

Genetic labeling of neurons with a specific response feature is an emerging technology for precise dissection of brain circuits that are functionally heterogeneous at the single-cell level. While immediate early gene mapping has been widely used for decades to identify brain regions which are activated by external stimuli, recent characterization of the promoter and enhancer elements responsible for neuronal activity-dependent transcription have opened new avenues for live imaging of active neurons. Indeed, these advancements provided the basis for a growing repertoire of novel experiments to address the role of active neuronal networks in cognitive behaviors. In this review, we summarize the current literature on the usage and development of activity-dependent promoters and discuss the future directions of this expanding new field

S1.28 Mechanochemical coupling of F1-ATPase and intracellular ATP imaging

Editat anteriorment amb el títol: Guia de recurso

Selective preparation of zero- and one-dimensional gold nanostructures in a TiO2 nanocrystal-containing photoactive mesoporous template

Nanocrystallized SiO2-TiO2 with tubular mesopores was prepared via the sol-gel technique. Gold was deposited in the tubular mesopores of the nanocrystallized SiO2-TiO2. The shape of the gold was varied from one-dimensional [1-D] to zero-dimensional [0-D] nanostructures by an increase in TiO2 content and ultraviolet [UV] irradiation during gold deposition. 1-D gold nanostructures [GNSs] were mainly obtained in the mesopores when a small amount of TiO2-containing mesoporous SiO2-TiO2 was used as a template, whereas the use of a template containing a large amount of TiO2 led to the formation of shorter 1-D or 0-D GNSs. UV irradiation also resulted in the formation of 0-D GNSs

Time Variability of Nonthermal X-ray Stripes in Tycho's Supernova Remnant with Chandra

Analyzing Chandra data of Tycho's supernova remnant (SNR) taken in 2000, 2003, 2007, 2009, and 2015, we search for time variable features of synchrotron X-rays in the southwestern part of the SNR, where stripe structures of hard X-ray emission were previous found. By comparing X-ray images obtained at each epoch, we discover a knot-like structure in the northernmost part of the stripe region became brighter particularly in 2015. We also find a bright filamentary structure gradually became fainter and narrower as it moved outward. Our spectral analysis reveal that not only the nonthermal X-ray flux but also the photon indices of the knot-like structure change from year to year. During the period from 2000 to 2015, the small knot shows brightening of $\sim 70\%$ and hardening of $\Delta \Gamma \sim 0.45$. The time variability can be explained if the magnetic field is amplified to $\sim 100~\mathrm{\mu G}$ and/or if magnetic turbulence significantly changes with time.Comment: 8 pages, 3 figures, 2 tables, accepted for publication in Ap

Indium(III) triflate-catalyzed reaction of 2-carbomethoxycyclobutanone with nitrones

2-Carbomethoxycyclobutanone reacted with N-phenyl-C-arylnitrones to afford methyl 5-oxo-2-[aryl(phenylamino)methyl]tetrahydrofuran-2-carboxylates by the catalysis of indium(III) triflate in the presence of magnesium sulfate. © 2012 Elsevier Ltd. All rights reserved

Rpd3/CoRest-mediated activity-dependent transcription regulates the flexibility in memory updating in Drosophila

Consolidated memory can be preserved or updated depending on the environmental change. Although such conflicting regulation may happen during memory updating, the flexibility of memory updating may have already been determined in the initial memory consolidation process. Here, we explored the gating mechanism for activity-dependent transcription in memory consolidation, which is unexpectedly linked to the later memory updating in Drosophila. Through proteomic analysis, we discovered that the compositional change in the transcriptional repressor, which contains the histone deacetylase Rpd3 and CoRest, acts as the gating mechanism that opens and closes the time window for activity-dependent transcription. Opening the gate through the compositional change in Rpd3/CoRest is required for memory consolidation, but closing the gate through Rpd3/CoRest is significant to limit future memory updating. Our data indicate that the flexibility of memory updating is determined through the initial activity-dependent transcription, providing a mechanism involved in defining memory state

An efficient procedure for preparation of 2-monoalkyl or 2-monoaryl-3-ethoxycyclobutanones

金沢大学医薬保健研究域薬学系Optimized reaction conditions for the preparation of various 2-monosubstituted 3-ethoxycyclobutanones are described. 2-Monoalkyl 3-ethoxycyclobutanones were efficiently prepared by the reaction of the corresponding carboxylic acid chlorides and an excess amount of ethyl vinyl ether in the presence of diisopropylethylamine at 90 °C in a sealed tube. 2-Monoaryl 3-ethoxycyclobutanones were prepared by using 2,6-lutidine as a base in the above-mentioned procedure. © 2010 Published by Elsevier Ltd. All rights reserved

Ring cleavage and successive aldol reaction of 3-[(Trialkylsilyl)methyl] cyclobutanones

3-[(Trialkylsilyl)methyl]cyclobutanones reacted with aldehydes by activation with titanium(IV) chloride to give acyclic β,γ;- unsaturated β′-hydroxyketones. © 2011 American Chemical Society