introduction: the purpose of this laboratory study was to evaluate the effect of acidic ph on the sealing ability of calcium-enriched mixture (cem) cement and mineral trioxide aggregate (mta) apical plugs. methods and materials: seventy single-rooted human maxillary anterior teeth were recruited. the teeth were randomly divided into 4 experimental groups ( n =15), and 1 negative and 1 positive ...

BACKGROUND AND AIMS Acid gastro-oesophageal reflux is one of the most important causes of chronic cough. The response to acid suppression in these patients is not as good as in patients with heartburn but improvement with antireflux surgery has been reported, suggesting the involvement of a non-acidic gastric component in the refluxate. Less acidic reflux may produce symptoms such as regurgitat...

Vipoxin is a heterodimeric neurotoxin isolated from the venom of the Bulgarian long-nosed viper Vipera ammodytes meridionalis. Vipoxin represents a noncovalent association of two subunits - a basic and toxic phospholipase A2 enzyme, and an acidic non-enzymatic component (vipoxin's acidic component). It was postulated that the phospholipase A2 subunit was more toxic than the whole vipoxin comple...

Tungsten oxide (WO3) and tungsten oxide hydrate (WO3.H2O) nanoparticles were synthesized via microwave-assisted solution combustion in comparison with the acidic precipitation method. Oxalic acid was used as a surfactant and forming agent in the acidic precipitation method. In addition to oxalic acid, glycine and citric acid were also used as fuels in the microw...

The acidic agent (SO3H) was stabilized on the silica coated Fe3O4 magnetic nanoparticles to produce Fe3O4@SiO2@Pr-SO3H, as a heterogeneous acidic catalyst, was designed, and then fully studied and characterized by FT-IR, XRD, TGA, DTA, TEM, and SEM analysis. Subsequently, the catalytic activity of Fe3O4...

In this study, a novel acidic magnetic dicationic ionic liquid was prepared in three steps to serve as a green  catalyst  in  organic  synthesis.  The  newly  synthesized  catalyst  was  characterized UV- VIS,  and  VSM  analysis.  Additionally,  the  decomposition  steps  acatalyst  were investigated by thermal  analysis  techniques  (TGA/DSC).  The  synthesized  acidic magnetic dication...

Oxidation of pyrite in aqueous solutions in contact with air (oxygen 20%) was studied at 25°C using short-term batch experiments. Fe and SO4 2 were the only dissolved Fe and S species detected in these solutions. After a short period, R [S]tot/[Fe]tot stabilized from 1.25 at pH 1.5 to 1.6 at pH 3. These R values were found to be consistent with previously published measurements (as calculated f...

T cell receptor recognition of antigen can lead either to T lymphocyte differentiation and proliferation or to a state of unresponsiveness, which is dependent on whether appropriate costimulatory signals are provided to the mature T cell. We have investigated a novel intracellular signaling pathway provided by the costimulatory molecule CD28. CD28 engagement triggers the activation of an acidic...

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...