The comparative study of the antimicrobial properties of Aloe vera juice and gel (leaf) extracts against selected clinical isolates have been investigated using standard microbiological methods. The organisms were Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Bacillus subtilis, Candida albicans and Aspergillus niger. The different extracts exhibited ant...

Organisms that use ammonium as the sole nitrogen source discriminate between [(15)N] and [(14)N] ammonium. This selectivity leaves an isotopic signature in their biomass that depends on the external concentration of ammonium. To dissect how differences in discrimination arise molecularly, we examined a wild-type (WT) strain of Escherichia coli K12 and mutant strains with lesions affecting ammon...

The objective of the current study was to investigate the ability of orthovanadate to induce aneuploidy in mouse sperm and micronuclei in mouse bone marrow cells at the same dose levels. The BrdU-incorporation assay was performed to test if the chemical treatment altered the duration of the meiotic divisions. It was found that orthovanadate (25mg/kg bw) treatment did not cause meiotic delay. To...

[3,5-2H]Salicylate was obtained by a hydrogen/deuterium exchange reaction carried out in 2H2O. Using this deuterated salicylate as a substrate for salicylate hydroxylase, the product catechol was isolated and characterized with respect to the positions of deuterium retention. Based on nuclear magnetic resonance and mass spectroscopy analyses, the product was identified as [3,5-2H]catechol. It i...

The photolysis of methyldeoxybenzoin was carried out in aqueous SDS solution in the earth’s field and in a field of 1500 G. Benzaldehyde and styrene are produced by disproportionation of benzoyl-set-phenethyl geminate radical pair. Both benzaldehyde and the recovered methyldeoxybenzoin are enriched in “C. These results represent the first direct evident that both disproportionation and recombin...

tope effect is consistent with accepted classical and quantum mechanical models. This Letter also provides a scaling relationship accurate at intermediate energies for differential electroncapture cross sections which is expected to be applicable to other types of differential cross sections involving hydrogen-isotope projectiles. This work was supported in part by the National Science Foundati...

Single crystals of novel orthorhombic (space group Pnnm) iron tetraboride FeB4 were synthesized at pressures above 8 GPa and high temperatures. Magnetic susceptibility and heat capacity measurements demonstrate bulk superconductivity below 2.9 K. The putative isotope effect on the superconducting critical temperature and the analysis of specific heat data indicate that the superconductivity in ...

Pairing of oxygen holes into heavy bipolarons in the paramagnetic phase and their magnetic pair breaking in the ferromagnetic phase (the so-called current-carrier density collapse) has accounted for the first-order ferromagnetic-phase transition, colossal magnetoresistance, isotope effect, and pseudogap in doped manganites. Here we propose an explanation of the phase coexistence and describe th...

Mass spectrometry is fundamental to measurements of isotope ratios for applications in isotope geochemistry, geochronology, and cosmochemistry. Magnetic-sector mass spectrometers are most common because these provide the best precision in isotope ratio measurements. Where the highest precision is desired, chemical separation followed by mass spectrometric analysis is carried out with gas (noble...