background and aims. the aim of this study was to compare shear bond strength (sbs) of metal and ceramic brackets bonded to enamel using acid versus er:yag laser etching. materials and methods. eighty premolars were divided into 4 groups: am (acid etching/ metal brackets), ac (acid etching/ ceramic brackets), lm (laser etching/ metal brackets) and lc (laser etching/ ceramic brackets). enamel co...

Thallium (Tl) is a highly toxic heavy metal that poses threat to various organisms, including human beings. In plants, Tl mostly present as the uncomplexed Tl+ species, and its uptake by plants follows similar trend of other monovalent ions such NH4+, Cs+, K+, Rb+, others. this study, we investigated relationships between concentrations in barley sunflower extractable-Tl acidic, neutral, alkali...

Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity....

Metal immobilization may contribute to the environmental management strategy of dredged sediment landfill sites contaminated by metals. In a field experiment, amendment effects and efficiency were investigated, focusing on plants, springtails and bacteria colonisation, metal extractability and sediment ecotoxicity. Conversely to hydroxylapatite (HA, 3% DW), the addition of Thomas Basic Slag (TB...

An analysis of the phospholipid ester-linked and the lipopolysaccharide (LPS) fatty acids and hydroxy fatty acids of six lactate-utilizing Desulfovibrio-type sulfate-reducing bacteria (SRB) has been performed using capillary gas-liquid chromatography-mass spectrometry (GLC-MS). The concentrations of normal fatty acids were essentially similar, with the possible exception of a high content of no...

A new method has been developed to analyze large numbers of air samples for trace metal content. To aid sample throughput, an Agilent Integrated Sample Introduction System (ISIS) was used with an Agilent 7500c Octopole Reaction System-ICP-MS operating in semiquantitative analysis mode. Using this methodology, 2,500 samples were analyzed for dissolved and extractable elemental composition in app...

[1] Surface sediments along a transect from an abyssal site in the northeastern Pacific (Station M, 34 500N, 123 000W) to a small mountainous river on the California coast (Santa Clara River) were studied to investigate the sources and cycling of organic matter on the continental margin. Sediment samples were separated into organic compound fractions (extractable lipids, amino acids (THAA), car...

Brain preparations from animals with scrapie or transmissible mink encephalopathy were phenol extracted and examined for the presence of pathogenic nucleic acid. Animals inoculated with various extracts remained healthy, and analysis on 2.6 to 5% polyacrylamide gels failed to detect a difference in extractable RNA species between infected and normal mink brain.

Free or eiisily extractable amino acids were determined by two-dimensional pnper chromatography in infarotcd and noninfarcted areas of the left ventricles of dog hearts after ligation of the anterior descending coronary artery. Changes in amino acid content in in fare ted areas were characterized by decreases in some of the major ninhydrin-reactive constituents and appeared coincidentally with ...

Leprosy bacilli harvested from freshly biopsied tissue from cases of lepromatous, borderline and histoid leprosy were, in conjunction with Mycobacterium lepraemurium and representative mycobacteria, examined cytochemically with and without their pyridine-extractable acid-fastness. Unlike the mycobacteria, unextracted leprosy bacilli failed to give a positive response to the periodic acid Schiff...