Efficient Synthesis of β‐Acetamido Ketones and Esters Using Aluminum Chloride as an Inexpensive and Green Catalyst

Aluminum chloride (AlCl₃) efficiently catalyzes one‐pot multicomponent condensation of enolizable ketones or alkyl acetoacetates with aldehydes, acetonitrile and acetyl chloride to afford β‐acetamido ketone or ester derivatives in high to excellent yields and in relatively short reaction times. Moreover, by this synthetic method, some novel β‐acetamido ketones and esters (i.e. one complex structure) are prepared.     

Spectrally resolved bioluminescence optical tomography

Spectrally resolved bioluminescence optical tomography is an approach to recover images of luciferase activity within a volume using multiwavelength emission data from internal bioluminescence sources. The underlying problem of uniqueness associated with nonspectrally resolved intensity-based bioluminescence tomography is highlighted. Reconstructed images of bioluminescence are presented by using as input both simulated and real multiwavelength data from a tissue-simulating phantom. The location of the internal bioluminescence is obtained with 1 mm accuracy. Further, the amplitude of the reconstructed source is proportional to the actual bioluminescence intensity.     

Role of lipids in urinary stones: studies of calcium oxalate precipitation at phospholipid langmuir monolayers

This article reviews the authors' experiments on calcium oxalate growth at lipid monolayers. Calcium oxalate is the principal mineral component of most urinary stones. Membrane constituents associate either actively or passively with calcific minerals during stone formation, and it has been proposed that lipid assemblies play a significant role, possibly providing sites for the initial nucleation event. Langmuir monolayers allow systematic studies of the heterogeneous precipitation of calcium oxalate at lipid assemblies. The influences of the chemical identity of the lipid headgroup, the organization of the monolayer, and the presence of heterogeneities and phase boundaries within the monolayer have been explored.     

An Improved Study of Electronic Band Structure and Optical Parameters of X-Phosphides (X=B,Al, Ga,In) by Modified Becke-Johnson Potential

We report the electronic band structure and optical parameters of X-Phosphides (X=B, Al,Ga,In) by first-principles technique based on a new approximation known as modified Becke-Johnson (mBJ). This potential is considered more accurate in elaborating excited states properties of insulators and semiconductors as compared to LDA and GGA. The present calculated band gaps values of BP, AlP, GaP, and InP are 1.867 eV, 2.268 eV, 2.090 eV, and 1.377 eV respectively, which are in close agreement to the experimental results. The band gap values trend in this study is as: Eg (mBJ-GGA/LDA)Eg (GGA) Eg (LDA). Optical parametric quantities (dielectric constant, refractive index, reflectivity and optical conductivity) which based on the band structure are also presented and discussed. BP, AlP, GaP, and InP have strong absorption in between the energy range 4-9eV, 4-7eV, 3-7eV, and 2-7eV respectively. Static dielectric constant, static refractive index and coefficient of reflectivity at zero frequency, within mBJ-GGA, are also calculated. BP, AlP, GaP, and InP show significant optical conductivity in the range 5.2-10eV, 4.3-8eV, 3.5-7.2eV, and 3.2-8eV respectively. The present study endorses that the said compounds can be used in opto-electronic applications, for different energy ranges.     

Kinetic evaluation of various isospecific active sites on MgCl2-supported Ziegler catalysts

The formation, variation and conversion of isospecific active sites were investigated, based on the isotacticity distribution of the polypropenes analyzed by the temperature rising elution fractionation (TREF) method. Stopped-flow polymerization of propene was carried out with a MgCl₂-supported Ziegler catalyst in the absence or presence of an internal or external electron donor so that the effects and roles of the electron donors could be clarified. The results showed that various kinds of active sites with different isospecificities, including the highest isospecific active sites responsible for producing the highest isotactic fraction (elution temperature: > 112°C) existed, even in the electron donor-free catalyst system. The isospecificity of the active sites in the donor-free catalyst might have originated from a surface monolayer multinuclear titanium species, namely an “island” of titanium species. The addition of the external electron donor converted a part of the aspecific and/or low isospecific active sites into the second highest isospecific active sites, but showed no effect on the formation of the highest isospecific active sites, whereas the addition of an internal donor played an important role in creating the highest isospecific active sites as well as suppressing the formation of the aspecific active sites.