4-Hydroxy-2-quinolones 145. <Emphasis Type="Italic">p</Emphasis>-Toluenesulfonylhydrazide as a tosylating agent

The reaction of ethyl 4-chloro-1-methyl-2-oxo-1,2-dihydroquinoline-3-carboxylate with p-toluene-sulfonylhydrazide in anhydrous solvents in the presence of triethylamine results in the tosylation of position 4 of the quinolone. Features of the steric structure of the tosyl-substituted compound are discussed. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 847–852, June, 2008.     

Primary and secondary effects in cosmic-ray variations at solar proton events

The variations of the cosmic-ray rigidity spectrum in the energy range from 0.8 MeV to several dozen GeV at solar proton events in January 2005 and December 2006 have been analyzed. A comparison of the observed and model spectra revealed the power range of direct detection of solar cosmic rays and moments of their observations.     

Polymeric composites based on alicyclic polyimide and polyaniline

Specific features of modification of an alicyclic polyimide with polyaniline were examined. The thus obtained new polymeric composites exhibit better capability for silver plating.     

The effect of composition of electrodeposited Ni-P alloys on the hydrogen evolution rate

The effect of composition and structure of electrodeposited nickel-phosphorus coatings on their catalytic properties in the hydrogen evolution reaction is studied. It is found that an increase in the content of phosphorus in the alloy from 0.1 to 12.6 wt % leads to an increase in the hydrogen evolution rate. The coatings, which were deposited under the galvanostatic conditions, exhibit higher activity than those plated under the potentiodynamic conditions. It is shown that the nature of acceleration of hydrogen evolution rate on the alloys depends on the alloy composition: only Ni-P alloys containing up to 6.5 wt % phosphorus possess true catalytic activity, whereas the coatings enriched in phosphorus promote the hydrogen evolution due to significant development of their surface area.     

4-Hydroxy-2-quinolones 141. Synthesis and structure of 5R-3-hydroxy-1,5-dihydropyrazolo[4,3-<Emphasis Type="Italic">c</Emphasis>]quinolin-4-ones

Treatment of 1R-4-chloro-3-ethoxycarbonyl-2-oxo-1,2-dihydroquinolines with p-toluenesulfonylhydrazide in refluxing ethanol and in the presence of triethylamine gives the 3-hydroxy-5R-1,5-dihydropyrazolo[4,3-c]quinolin-4-ones. The possible mechanism of formation, features of the steric structure of the synthesized compounds, and their NMR and mass spectra are discussed. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 233–238, February, 2008.     

Polymeric formulations based on alicyclic polyimide and poly(ethylene glycol)

New polymeric composites based on alicyclic polyimide with poly(ethylene glycol) having a molecular mass of 2000, 3000, and 8000 were obtained and their basic physicomechanical, optical, and electrical properties were studied. It is shown that the new film-type composite material has better thermal characteristics in comparison with the starting polyimide.     

Study of the local structure of the cathode material Li x NiO2 (x=0.7): Analysis of the Near-Edge Fine Structure of the X-ray Absorption Spectra

The x-ray fine-structure absorption spectra of the cathode material Li _x NiO₂ were measured near the Ni K edge. The spectra were recorded directly during a charging/discharging cycle of a battery containing this material. Analysis of the local structure of the nickel environment in Li_0.7NiO₂ was performed by comparing the experimental spectrum with the theoretical spectra calculated within several structural models. The results obtained allow one to conclude that, in the stage of battery charging, the transition to the monoclinic phase is possible at some lithium concentration.     

Microstructure and mechanical properties of V–4Ti–4Cr alloy as a function of the chemical heat treatment regimes

The regularities of the formation of a heterophase structure and mechanical properties of V–4Ti–4Cr alloy as a function of thermomechanical and chemical heat treatments are studied. The regimes of thermomechanical treatment which provide the formation of a heterophase structure with a homogeneous volume distribution of oxycarbonitride nanoparticles with a size of about 10 nm and an increase in the volume content and thermal stability of this phase and which provide an increase in the temperature of alloy recrystallization are developed. The formation of the heterophase structure results in a substantial (up to 70%) increase in the short-term high-temperature strength of the alloy at T = 800°C. The increase in the strength is achieved while keeping a rather high level of plasticity.     

The effect of thermomechanical treatment regimes on microstructure and mechanical properties of V–Me(Cr,W)–Zr–C alloys

The regularities of the formation of a heterophase structure in dispersion-strengthened vanadium V–Me(Cr, W)–Zr–C alloys are studied as a function of the regimes of their thermomechanical treatment. The regimes of treatment providing a substantial increase in the dispersity and homogeneity of spatial distribution of ZrC particles, temperature of recrystallization, and high-temperature (at T = 800°C) short-time strength are found in comparison to conventional treatment regimes.     

The Lysine48‐Based Polyubiquitin Chain Proteasomal Signal: Not a Single Child Anymore

The conjugation of ubiquitin (Ub) to proteins is involved in the regulation of many processes. The modification serves as a recognition element in trans, in which downstream effectors bind to the modified protein and determine its fate and/or function. A polyUb chain that is linked through internal lysine (Lys)‐48 of Ub and anchored to an internal Lys residue of the substrate has become the accepted “canonical” signal for proteasomal targeting and degradation. However, recent studies show that the signal is far more diverse and that chains based on other internal linkages, as well as linear or heterologous chains made of Ub and Ub‐like proteins and even monoUb, are recognized by the proteasome. In addition, chains linked to residues other than internal Lys were described, all challenging the current paradigm.