Superlattice geometry for gamma-ray lasers

The central problem to developing a graser—that pumping can inhibit or destroy the Mössbauer and Borrmann effects—can conceivably be mitigated by a superlattice geometry, into which collimated coherent transfer radiation is introduced to form a multiwave Borrmann (or anti-Borrmann) mode. Such a geometry is introduced, and its effects on pump intensity and lattice heating are discussed.     

Biomimetic synthesis of (±)-aculeatin D

A practical, efficient and diastereoselective synthesis of the cytotoxic and antiprotozoal compound aculeatin D (1) is described, employing a biomimetic oxidative cyclisation cascade reaction to generate the tricyclic system of the natural product. The synthesis proceeds in ten steps from commercially available 1-tetradecanol.     

Preparation of123I-α-(p-iodoanilino)phenylacetonitrile using HPLC

Synthesis of α-(p-iodoanilino)phenylacetonitrile (IAPAN), an amygdalin analog, labeled with I-123 (t1/2 13.3 hr) in a carrier-free state (i.e. no-carrier-added) was made possible by virtue of the high speed, sensitivity, and resolving power of HPLC. Aniline was iodinated by the action of no-carrier-added Na¹²³I in the presence of Cu(II), and the resulting iodaniline was reacted with benzaldehyde followed by the addition of HCN to yield the title compound. The radioactive IAPAN was separated from α-anilinophenylacetonitrile and other byproducts by reversed phase partition chromatography on an octadecylsilane column using 50% ethanol/H₂O as eluent. The product was correlated with authentic, classically characterized IAPAN, and with¹²³I IAPAN prepared by electrophilic exchange of IAPAN and ICl iodination of α-anilinophenylacetonitrile.     

Production of ethanol from enzymatically hydrolyzed orange peel by the yeastSaccharomyces cerevisiae

Applied Biochemistry and Biotechnology - We extended our previous investigations of enzymatic hydrolysis of polysaccharides in orange peel by commercial cellulase and pectinase enzymes to higher,...     

Characteristics of selenium in australian marine biota

The occurrence, distribution and speciation of selenium in Australian marine biota is discussed. Biochemical pathways for the accumulation of selenium by marine organisms are also postulated. Comparison of the levels of selenium in macroalgae, fish, crustaceans and molluscs indicates that preferential accumulation of selenium by particular taxa does not occur. Phaeophyta have significantly lower selenium concentrations than Rhodophyta and Chlorophyta. Fish have lower selenium contents in muscle tissues than molluscs and crustaceans. Marine animals with different dietary intake (planktonic vs herbivorous vs carnivorous) are not observed to have significantly different levels of selenium (P>0.05). Selenium in all the organisms studied was predominantly associated with free amino-acids or protein residues and was not present as characterizable inorganic selenium species (SeO₃^2?, SeO₄^2?). These results indicate that selenium is probably only incorporated into biota for specific biochemical purposes with any exces selenium being excreted or eliminated.     

The preparation of a phosphorus doped silicon film from phosphorus containing silicon nanoparticles

Phosphorus containing and octyl-terminated silicon nanoparticles (NPs) are generated by a solution reduction route under room temperature conditions for the first time and characterized by TEM, HRTEM, EDX, 1H/13C/31P NMR, EPR, and PL spectroscopy, then annealed to form a thin film with phosphorus doping confirmed by microprobe elemental analyses.