The effect of the use of 2% chlorhexidine gel in post-space preparation on carbon fiber post retention

Objective. Evaluate the bond strength of a resin cement used to lute carbon fiber posts, when drills and 4 different substances were used for the post-space preparation. Study design. Forty human canines were treated endodontically, and had a 10-mm length post space preparation. Four different substances were used with the drills: G1 - saline, G2 - 2% chlorhexidine gel, G3 - EDTA/NaOCl, and G4 - xylene. Carbon fiber posts (C-Post) were cemented with Allbond2 and Hi-X. Then, the posts were dislodged by tensional forces. Results. The groups of chlrohexidine (G2) and xylene (G4) obtained superior average values of bond strength at the 5% significance level (Parametric analyzes ANOVA/Tukey/Scheffe) differing statistically from the other groups. There was no statistical significant difference between groups 2 and 4. Conclusion. Xylene and chlorhexidine gel are good substances for the post-space preparation but the second has the advantage of antimicrobial activity and low toxicity.99337237

Water quality and bead loss in irrigation filters

Among the irrigation systems used today, trickle irrigation is one of the most efficient methods. This research, conducted by means of field tests, had the objective of comparing head loss evolution on water filtration with a disc filter (130 mum) and a non-woven synthetic fabric filter used in a drip irrigation system. The test consisted of fertirrigation with organic fertilizer, and chemical treatment of the water with sodium hypochlorite. Physical, chemical, and biological parameters were analyzed, such as: pH, turbidity, suspended solids, dissolved solids, EC, hardness, Langelier index, total iron, manganese, sulfides, algae, and bacteria. The water source used in this experiment was from an open reservoir, where an experimental trickle irrigation system had been installed. The research was developed in four steps lasting 30 days each, during different seasons. The chemical factors pH, total iron, and concentration of sulfides presented a medium risk of clogging the emitters. All other physical and biological water quality parameters analyzed resulted in values that did not present an emitter-clogging risk. There was a correlation of results between physical parameters turbidity, suspended solids, and algae, and suspended solids. Fertirrigation influenced water quality. The concentration of free chlorine was higher in the effluent from the disc filter. Head loss evolution in the non-woven synthetic fabric filter was more striking and faster than in the disc filter.61656357

In search of a tolerance-induction strategy for cow's milk allergies: significant reduction of beta-lactoglobulin allergenicity via transglutaminase/cysteine polymerization

OBJECTIVE: To explore the use of beta-lactoglobulin polymerized using microbial transglutaminase and heating to identify whether protein polymerization could reduce in vivo allergenicity and maintain in vitro and ex vivo immunoreactivity for use in tolerance-induction protocols. METHODS: Based on previous protocols applied in mice and children, we performed in vivo challenges (using a skin prick test) with native and polymerized beta-lactoglobulin in adult patients with an IgE-mediated allergy to beta-lactoglobulin. In vitro humoral immunoreactivity was analyzed using immunoblotting. Cell-mediated immunoreactivity was analyzed using ex vivo challenges with native and polymerized beta-lactoglobulin and monitored by leukocyte adherence inhibition tests. RESULTS: The skin tests demonstrated that there was a significant reduction in immediate cutaneous reactivity after polymerization. Polymerization did not decrease the immunoblotting detection of s-IgE specific to beta-lactoglobulin. Cell-mediated immunoreactivity, as assessed by ex vivo challenges and leukocyte adherence inhibition tests, did not exhibit significant differences between leukocytes challenged with native versus polymerized beta-lactoglobulin. CONCLUSIONS: The polymerization of beta-lactoglobulin decreased in vivo allergenicity and did not decrease in vitro humoral or ex vivo cell-mediated immunoreactivity. Therefore, we conclude that inducing polymerization using transglutaminase represents a promising technique to produce suitable molecules for the purpose of designing oral/sublingual tolerance induction protocols for the treatment of allergies.67101171117