objective: orthodontic wires should have high resistance against corrosion in the oral environment. since the effect of ph on corrosion has been well recognized, this study sought to assess and compare the electrochemical corrosion of orthodontic brackets and wires of different brands in acidic artificial saliva.   methods: this in vitro experimental study was conducted on 24 mandibular central...

Soil acidity is a major constraint on plant productivity. Arbuscular mycorrhizal (AM) fungi support plant colonization in acidic soil, but soil acidity also constrains fungal growth and diversity. Fungi in extreme environments generally evolve towards specialists, suggesting that AM fungi in acidic soil are acidic-soil specialists. In our previous surveys, however, some AM fungi detected in str...

An association has been established between human Ia-like (Ia) antigenic determinants, expression during DNA synthesis on granulocyte-macrophage colony forming cells (CFU-GM) and the regulatory action of acidic isoferritins in vitro. Treatment of human bone marrow cells with monoclonal-anti-Ia-like (Ia) plus complement inhibited colony and cluster formation by approximately 50% but did not affe...

Solid tumors are characterized by acidic extracellular pH (pHe). The present study examined the contribution of small GTP-binding proteins to phospholipase D (PLD) activation of acidic pHe-induced matrix metalloproteinase-9 (MMP-9) production. Acidic pHe-induced MMP-9 production was reduced by C3 exoenzyme, which inhibits the Rho family of GTPases; cytochalasin D, which inhibits actin reorganiz...

In Escherichia coli, coordinated activation and deactivation of DnaA allows for proper timing of the initiation of chromosomal synthesis at the origin of replication (oriC) and assures initiation occurs once per cell cycle. In vitro, acidic phospholipids reactivate DnaA, and in vivo depletion of acidic phospholipids, results in growth arrest. Growth can be restored by the expression of a mutant...

quantitative determination of br?nsted acid sites in acidic mordenite samples with varying proton concentrations has been studied using aqueous conductometric titration method. conductometric titration of the ammonium form of mordenite with sodium hydroxide is feasible and the results indicate potential number of br?nsted acid sites. however, br?nsted acid sites concentration in acidic mordenit...

in the present of methylimidazolium hydrogen sulfate, the synthesis of arylidene heterobicyclic pyrimidinones is studied by condensation of aromatic aldehyde, cyclopentanone, and urea or thiourea. using solvent-free conditions, non-toxic and inexpensive materials, simple and clean work-up, short reaction times and good yields of the products are the advantages of this method.

a simple and efficient one-pot method for the preparation of aromatic iodides has been developed by sequential diazotization–iodination of aromatic amines employing sodium nitrite and sodium iodide in the presence of acidic ionic liquid n-methyl-2-pyrrolidonum hydrosulfate ([h-nmp]hso4). the diazonium salts that are formed by this ionic liquid are stable at room temperature and react rapidly wi...

objective(s): activation of acid-sensing ion channel 1a (asic1a) is responsible for tissue injury caused by acidosis in nervous systems. but its physiological and pathological roles in nucleus pulposus cells (npcs) are unclear. the aim of this study is to investigate whether asic1a regulates the survival of npcs in the acidic environment of degenerated discs. materials and methods: npcs were is...

Dendritic spines are morphing structures believed to provide a cellular substrate for synaptic plasticity. It has been suggested that the actin cytoskeleton is the target of molecular mechanisms regulating spine morphology. Here we hypothesized that acidic calponin, an actin-binding protein, is one of the key regulators of actin filaments during spine plasticity. Our data showed that the overex...