nano silica-h2so4 is an efficient and mild catalysis system for the regeneration of aldehyde from aldoximes. ketoximes are converted to amides by beckmann rearrangement in the presence of nano silica-h2so4. the reactions are carried out in solvent-free conditions under microwave irradiation (600 w) within 50-120 sec in good yields.

cyanobacteria are well known for their production of a multitude of highly toxic substances . the genus stigomena is regarded as good candidates for producing biologically active secondary metabolites, which are highly toxic to humans and other animals. the carcass of a dog was found at the shore of lake ali-abad, iran. biomass from the discovery site appeared to be of cyanobacterial nature. we...

aquatics are a source of bioactive compounds that these compounds have different properties such as antimicrobial activity. in this study, antibacterial activity of methanol, chloroform and hexane extracts from body wall, gonad and intestine of sea cucumber holothuria leucospilota was evaluated against bacillus subtilis, pseudomonas aeruginosa and staphylococcus aureus. bioactive compounds of b...

background: the antioxidant components have been identified in some pine species. antioxidant properties of proantocyanidins reduce free radicals induced by dna fragmentation and lipid proxidation and also proanthocyanidines could curb lipid peroxidation. objective: in this study, we analyzed different parts of pinus eldarica (bark, seed and needle) and assessed their antioxidant contents. meth...

the angular dependent magnetoresistance oscillation (admro) of the stage-2 ibr graphiteintercalation compound (gic) was studied between 1.8 k and 110 k in magnetic fields between 1 and 9t. there was a series of peaks in the c-axis resistance as the field direction was changed from the c axisto the (001) plane. the field independence of the angular positions of the peaks, showing that theoscilla...

synthesis and characterization of 6-(hydroxymethyl)-14, 16-dimethyl-13, 14, 16, 17-tetrahydro-6h-13, 17-epiminodibenzo [e, l] [1, 4] dioxacyclotridecin-15 (7h)-oneabstractnew 6-(hydroxymethyl)-14, 16-dimethyl-13, 14, 16, 17-tetrahydro-6h-13, 17-epiminodibenzo [e, l] [1, 4] dioxacyclotridecin-15 (7h)-one (2a) was synthesized in good yield by the petrenko–kritchenko reaction of 2, 2'-((3-hydroxyp...

learning vocabulary constitutes a crucial step in language learning. amongst different word categories, compound words have failed to attract the attention they deserve. this led us to conduct a study trying to pinpoint the difficulties learning these words and to suggest some techniques facilitating their acquisition. to that effect, a questionnaire as well as a vocabu-lary test were given to ...

Submit Manuscript | http://medcraveonline.com commonly seen in permanent dentition. The incidence of supernumerary teeth is 1-3% and approximately 90-98% of supernumerary teeth occur in the maxilla. Males are affected twice as frequently as females [1]. Mesiodens is the most frequently occurring supernumerary tooth located palatal to the central incisors and conical morphology was found to be m...

Introduction Hypoplasia is defined as a quantitative defect of enamel visually and is histomorphologically identified as an external defect involving the surface of the enamel and associated with reduced thickness of enamel (Ozturk et al, 2004).Turner's hypoplasia usually manifests as a portion of missing or diminished enamel, generally affecting one or more permanent teeth in the oral cavity. ...