Micro‐computed tomography analysis of enamel structure after different bleaching treatments

The aim of this investigation is to assess effect of three different bleaching techniques on structural integrity, mineral density and volume of enamel via micro-computed tomography (micro-CT) and examine color changes by CIELAB and CIEDE2000 formulas. Twenty-four upper premolar teeth were randomly separated into three different groups (n = 8) (group 1, 35% hydrogen peroxide (HP) gel with Er,Cr:YSGG laser activation; group 2, 35% HP gel with diode laser activation; group 3, 35% HP gel with chemically activation). High-resolution micro-CT system (Bruker Skyscan 1275, Kontich, Belgium) was carried out to scan samples. Each tooth was scanned twice before-after application of bleaching with same scanning parameters. Structural thickness, structural separation, fragmentation index, mineral density, and mineral volume of enamel were calculated for each region of interest (ROI). Color changes were measured with spectrophotometer and calculated with CIELAB and CIEDE2000 formulas. Data analysis was made with one-way ANOVA with post-hoc LSD. Micro-CT analysis indicated that statistically significant differences were found in structural thickness, and separation, mineral density, and mineral volume of enamel for different ROIs before and after whitening for whole groups (P .05). All bleaching applications exhibited similar efficiency on the enamel surface. Nevertheless, bleaching process with Er,Cr:YSGG laser had less negative effects on enamel as it showed less change in enamel compared to other bleaching treatments. Micro-CT analysis of histomorphometric parameters can be useful for further mineralization studies of dental hard tissues

Copper enhances the activity and salt resistance of mixed methane-oxidizing communities

Effluents of anaerobic digesters are an underestimated source of greenhouse gases, as they are often saturated with methane. A post-treatment with methane-oxidizing bacterial consortia could mitigate diffuse emissions at such sites. Semi-continuously fed stirred reactors were used as model systems to characterize the influence of the key parameters on the activity of these mixed methanotrophic communities. The addition of 140 mg L-1 NH (4) (+) -N had no significant influence on the activity nor did a temperature increase from 28A degrees C to 35A degrees C. On the other hand, addition of 0.64 mg L-1 of copper(II) increased the methane removal rate by a factor of 1.5 to 1.7 since the activity of particulate methane monooxygenase was enhanced. The influence of different concentrations of NaCl was also tested, as effluents of anaerobic digesters often contain salt levels up to 10 g NaCl L-1. At a concentration of 11 g NaCl L-1, almost no methane-oxidizing activity was observed in the reactors without copper addition. Yet, reactors with copper addition exhibited a sustained activity in the presence of NaCl. A colorimetric test based on naphthalene oxidation showed that soluble methane monooxygenase was inhibited by copper, suggesting that the particulate methane monooxygenase was the active enzyme and thus more salt resistant. The results obtained demonstrate that the treatment of methane-saturated effluents, even those with increased ammonium (up to 140 mg L-1 NH (4) (+) -N) and salt levels, can be mitigated by implementation of methane-oxidizing microbial consortia

Quality of life and related factors among chronic hepatitis B-infected patients: a multi-center study, Turkey.

BACKGROUND: The aim of this study was to assess health-related quality of life (HRQOL) among chronic hepatitis B (CHB) patients in Turkey and to study related factors. METHODS: This multicenter study was carried out between January 01 and April 15, 2015 in Turkey in 57 centers. Adults were enrolled and studied in three groups. Group 1: Inactive HBsAg carriers, Group 2: CHB patients receiving antiviral therapy, Group 3: CHB patients who were neither receiving antiviral therapy nor were inactive HBsAg carriers. Study data was collected by face-to-face interviews using a standardized questionnaire, Short Form-36 (SF-36) and Hepatitis B Quality of Life (HBQOL). Values equivalent to p < 0.05 in analyses were accepted as statistically significant. RESULTS: Four thousand two hundred fifty-seven patients with CHB were included in the study. Two thousand five hundred fifty-nine (60.1 %) of the patients were males. Groups 1, 2 and 3, consisted of 1529 (35.9 %), 1721 (40.4 %) and 1007 (23.7 %) patients, respectively. The highest value of HRQOL was found in inactive HBsAg carriers. We found that total HBQOL score increased when antiviral treatment was used. However, HRQOL of CHB patients varied according to their socio-demographic properties. Regarding total HBQOL score, a higher significant level of HRQOL was determined in inactive HBV patients when matched controls with the associated factors were provided. CONCLUSIONS: The HRQOL score of CHB patients was higher than expected and it can be worsen when the disease becomes active. Use of an antiviral therapy can contribute to increasing HRQOL of patients