Plexin B3 promotes neurite outgrowth,interacts homophilically,and interacts with Rin

Background  

Plexins, known to date as receptors of semaphorins, are implicated in semaphorin-mediated axon repulsion and growth cone collapse. However, subtype-specific functions of the majority of the nine members of the mammalian plexin family are largely unknown. In order to investigate functional properties of B-plexins, we analyzed the expression of human and murine plexin B3 and expressed full-length human plexins B2 (B2) and B3 (B3) in NIH-3T3 cells.     

LiInSe2 nanosecond optical parametric oscillator

Optical parametric oscillation using the new lithium selenoindate nonlinear crystal is reported for what is to our knowledge the first time. A 17 mm long, type II phase-matched sample is pumped by a 10 ns Nd:YAG laser. The minimum pump energy threshold is 3 mJ for a signal-resonant configuration. The signal and idler waves are tunable between 1.47 and 1.57 microm, and 3.3 and 3.78 microm, with a total output energy of 170 microJ corresponding to a 2.4% energy conversion at 8 mJ pump, only limited by the AR coatings damage. With optimized crystal quality and coatings, lithium selenoindate should show superior performance as compared with AgGaS(e)2 crystals, owing to its 4x larger thermal conductivity.     

Addition of secondary phosphines to a vinyl ether of diacetone-d-glucose: a new approach to optically active phosphines and their derivatives

Secondary phosphines react readily with a vinyl ether of diacetone-d-glucose under radical initiation conditions to give, in high yield, anti-Markovnikov adducts, diorganyl{2-[3-O-(1,2:5,6-di-O-isopropylidene)-d-glucofuranosyloxy]ethyl}phosphines, which oxidize almost quantitatively upon reacting with air oxygen or elemental sulfur to form the corresponding optically active phosphine oxides or sulfides.     

HPLC determination of estradiol, its degradation product, and preservatives in new topical formulation Estrogel HBF

This paper deals with the development of a novel method for simultaneous determination of estradiol, its degradation product estrone, and two preservatives, methylparaben and propylparaben, in the topical preparation Estradiol HBF. After optimization of the analytical conditions the method was validated and applied in studies of the stability of the topical preparation Estrogel HBF. Separation of all these compounds was performed on a Supelco Discovery C18 (250 mm×3.0 mm, 5 m) analytical column. A mixture of acetonitrile, methanol, and water (23:24:53 v/v) was chosen as mobile phase. UV absorbance at 225 nm was used for detection and quantitation of analytes. The total analysis time was less than 12 min at a flow rate of 0.9 mL min^–1. All the compounds were isolated from the topical gel by simple extraction with an acetonitrile solution of hydrocortisone, as internal standard, and using sonication and centrifugation thereafter. The supernatant was injected directly on to the analytical column. The recovery of the procedure was from 96.9 to 100.4%. Validation of method according international guidelines was successfully performed.     

The trans-1,4-cyclohexylene group as a structural fragment in liquid crystals

In this review the effect on physico-chemical and electro-optical properties of the introduction of the trans-1,4-cyclohexylene fragment into the molecular core of liquid crystals is discussed, rationalized in terms of existent theories, and compared with the effect of other well-known molecular fragments.     

Thermal properties of volatile ruthenium(III) complexes

Complexes of ruthenium(III) with the following beta-diketone derivatives: 2,4-pentanedione (Ru(acac)₃), 1,1,1,6,6,6-hexafluoro-2,4-pentanedione (Ru(hfac)₃), and 2-methoxy-2,6-dimethyl-3,5-heptanedione (Ru(mdhd)₃) were synthesized, purified, and identified by chemical analysis and melting points. By difference-scanning calorimetry (DSC) in vacuum the thermodynamic characteristics of melting processes were defined. Using the static method with quartz membrane zero-manometer, the temperature dependencies of saturated and unsaturated vapor pressure were obtained for Ru(hfac)₃. The standard thermodynamic characteristics of vaporization processes enthalpy ?H _T* and entropy ?S° _T* were determined.     

On the absolute instability of semi-implicit schemes for hydrostatic models

The dependence of the linear stability of two-time-level finite-difference semi-implicit schemes on the choice of reference temperature profile is studied. Particular vertical profiles of the temperature are considered to derive analytical conditions of stability. Analysis is made for general form of different model parameters such as the number of vertical levels and their distribution, the time step size, and the values of the viscosity coefficients. The derived conditions of stability are more restrictive than those for three-time-level schemes, but obtained necessary and sufficient condition for constant vertical lapse rates of the temperature has the form frequently applied to three-time-level schemes: the basic temperature profile should be warmer than the actual one. Performed numerical experiments show that the last restriction is neither necessary nor sufficient condition of stability for general temperature profiles.     

Copper‐Polymer Nanocomposite Catalyst for Synthesis of 1,4‐Diphenylbutadiyne‐1,3

A new catalyst for cross‐coupling synthesis of 1,4‐diphenylbutadiyne‐1,3 was prepared by thermolysis of copper(II) poly‐5‐vinyltetrazolate. It presents heterogeneous catalyst, in which copper nanoparticles are supported on polymeric matrix surface. The catalyst is recovered, recycled, and shows high catalytic activity in cross‐coupling synthesis of 1,4‐diphenylbutadiyne‐1,3. The reaction proceeds in aerobic conditions at room temperature in the presence of pyridine.     

Pyrazolyc 3-hydroxychromones: Regulation of ESIPT reaction by the “flavonol-like” intramolecular hydrogen bonding to carbonyl group oxygen,which dominates over the “alternative” H-bond to heterocyclic nitrogen

Two isomeric pyrazole derivatives of 3-hydroxychromone (3HC) with and without the possibility of the multiple intramolecular hydrogen bonds formation were compared theoretically and experimentally with the aim to find out whether the excited state intramolecular proton transfer (ESIPT) reaction follows the traditional to the most of 3HCs “flavonol-like” direction towards the CO group oxygen or an “alternative” direction towards the heterocyclic nitrogen atom.Quantum-chemical modeling and comparative study of the experimental spectral parameters of the title compounds indicated the preferential realization of “flavonol-like” ESIPT to oxygen channel.The 3HC systems with the “alternative” intramolecular hydrogen bond to nitrogen were characterized as low fluorescent and practically unable to ESIPT with participation of the nitrogen containing heterocyclic unit.     

Surprising secondary photochemical reactions observed on conventional photolysis of diazotetrahydrofuranones

The formation of C-H insertion products of the terminal N-atom of a diazo group into the α-СН-bond of tetrahydrofuran during direct photolysis of regioisomeric 2,2-dimethyl-5,5-diphenyl and 5,5-dimethyl-2,2-diphenyl-substituted 3-diazotetrahydrofuran-4-ones in THF is dictated by photochemical cycloelimination of the originally formed (1,1-dimethyl-2-oxa-3,3-diphenyl-propano)ketene and oxetanecarboxylic acid derivatives to yield benzophenone. The latter, under subsequent UV irradiation of the reaction mixture, initiates sensitized photolysis of the starting diazoketones resulting in the appearance of the insertion products with the solvent.