Synthesis and Evaluation of ABO3 Perovskites (A=La and B=Mn, Co) with Stoichiometric and Over-stoichiometric Ratios of B/A for Catalytic Oxidation of Trichloroethylene

In this contribution, perovskite catalysts (ABO3) were probed that site A and site B were occupied by lanthanum and transition metals of manganese or cobalt, respectively, with stoichiometric ratios as well as 20 % over-stoichiometric ratios of B/A. The perovskite samples were synthesized using a gel-combustion method and characterized by BET, XRD, SEM and O2-TPD analyses. After mounting in a fixed bed reactor, the catalysts were examined in atmospheric pressure conditions at different temperatures for oxidation of 1000 ppm trichloroethylene in the air. Evaluation of over-stoichiometric catalysts activity showed that the increased ratio of B/A in the catalysts compared to the stoichiometric one led to BET surface area, oxygen mobility, and consequently catalytic performance improvement. The lanthanum manganite perovskite with 20 % excess manganese yielded the best catalytic performance among the probed perovskites.

Anti-bacterial properties of calcium hydroxide in combination with silver, copper, zinc oxide or magnesium oxide

Prevention of bacterial growth among root canal treatment sessions is a prerequisite for successful root canal treatment. The most common way to achieve this is to use calcium hydroxide in the treatment sessions. Some studies have shown calcium hydroxide inefficiency in this field. The aim of this study was to investigate and compare the effects of silver, copper, zinc oxide and magnesium oxide nanoparticles on the inhibitory effects of calcium hydroxide based on Enterococcus faecalis species. Enterococcus faecalis bacteria having 0.5 McFarland concentration were prepared. Plates containing BHI agar medium were prepared. In each plate, four wells were created and the plate was cultured using a sterile swab. Afterwards, calcium hydroxide composition of 1% and 2% concentration from silver, copper, zinc oxide and magnesium oxide nanoparticles were prepared separately, as well as the combination of calcium hydroxide with 1% silver in combination with 1% of copper, zinc oxide and magnesium oxide nanoparticles, which were then transferred to the wells. After 24 hours of incubation, the inhibition zone diameter was measured. Data were analyzed by Mann-Withney test. At 1% concentration, only the combination of copper nanoparticles with calcium hydroxide could significantly create an inhibition zone larger than calcium hydroxide alone (P value<0.5). At 2% concentration, the combination of copper nanoparticles with calcium hydroxide, and the combination of silver nanoparticles with calcium hydroxide, were significantly higher than calcium hydroxide alone (P value<0.5). The calcium hydroxide composition containing 1% silver nanoparticles in combination with 1% copper, zinc oxide and magnesium oxide nanoparticles significantly increased the growth inhibition zone more than calcium hydroxide alone. (P Value<0.5). Copper nanoparticles showed the best antibacterial properties among silver, copper, magnesium oxide and zinc oxide nanoparticles in combination with calcium hydroxide. Also, the combination of 1% of nanoparticles with each other increases antibacterial properties

Synthesis and Evaluation of ABO3 Perovskites (A=La and B=Mn, Co) with Stoichiometric and Over-stoichiometric Ratios of B/A for Catalytic Oxidation of Trichloroethylene

In this contribution, perovskite catalysts (ABO3) were probed that site A and site B were occupied by lanthanum and transition metals of manganese or cobalt, respectively, with stoichiometric ratios as well as 20 % over-stoichiometric ratios of B/A. The perovskite samples were synthesized using a gel-combustion method and characterized by BET, XRD, SEM and O2-TPD analyses. After mounting in a fixed bed reactor, the catalysts were examined in atmospheric pressure conditions at different temperatures for oxidation of 1000 ppm trichloroethylene in the air. Evaluation of over-stoichiometric catalysts activity showed that the increased ratio of B/A in the catalysts compared to the stoichiometric one led to BET surface area, oxygen mobility, and consequently catalytic performance improvement. The lanthanum manganite perovskite with 20 % excess manganese yielded the best catalytic performance among the probed perovskites. Copyright © 2018 BCREC Group. All rights reserved Received: 28th April 2017; Revised: 31st July 2017; Accepted: 4th August 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018 How to Cite: Alagheband, R., Maghsoodi, S., Kootenaei, A.S., Kianmanesh, H. (2018). Synthesis and Evaluation of ABO3 Perovskites (A=La and B=Mn, Co) with Stoichiometric and Over-stoichiometric Ratios of B/A for Catalytic Oxidation of Trichloroethylene. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1): 47-56 (doi:10.9767/bcrec.13.1.1188.47-56

Application of Real-Time PCR method for evaluation of measles vaccine heat stability

     The Plaque Forming Unit(PFU) and Tissue Culture Infectious Dose50(TCID50) methods are used for evaluation of vaccine heat stability and effect of various stabilizers on thermal stability of vaccines. The aim of present study is using Real-Time PCRtechniquefor estimation of vaccine degradation rate and thermal stability of measles vaccines. Lyophilized measles vaccines containing three various stabilizers were reconstituted with distilled water. Three vial of each vaccine incubated at25˚C for 0, 4 and 8 hours. Titer of virus in vaccines calculated by TCID50 method. Also after RNA Extraction and cDNA synthesis, the RNA copy numbers of viruses in vaccines were estimated by absolute quantitative Real-Time PCRtesting. The data were analyzedby SPSS 19 and Sigma Plot 11 software.The result of this study showed there is a significant relationshipbetween vaccine degradation rate calculated with TCID50 and Real-Time PCR method (p&lt;0.05). ThereforeReal-Time PCR is a good complement or appropriate replacement to traditional methods.Titration methods based on cell culture are gold tests for titration of viral vaccines and estimation of heat stability but Real-Time PCR technique can also be used for this goals. This method is faster, cheaper and easier than TCID50

Cell Toxicity and inhibitory effects of Cyperus rotundus extract on Streptococcus mutans, Aggregatibacter actinomycetemcomitans and Candida albicans

Periodontitis and tooth decay are common dental diseases. There are some bacterial risk factors such as Streptococcus mutans, Aggregatibacter actinomycetemcomitans and Candida albicans fungi. Considering the increasing resistance of bacteria and fungi to antibiotics and their complications, tubers of Cyperus rotundus was used to determine the antimicrobial effect of alcoholic and aqueous extracts and essential oil on Streptococcus mutans, Aggregatibacter actinomycetemcomitans and Candida albicans, as well as an examination cytotoxicity on gingival fibroblast cells. Alcoholic and aqueous extracts and essential oil prepared from tubers of Cyperus rotundus. After bacterial and fungal cultures, the inhibition zone, Minimum inhibitory concentrations (MIC), and Minimum Bactericidal Concentration (MBC), were studied. Cytotoxicity was also evaluated using the Methyl tetrazolium test (MTT).The results showed that Cyperus rotundus alcoholic extract had the greatest effect on inhibition of growth and death of Streptococcus mutans, Aggregatibacter actinomycetemcomitans. According to the present study, Cyperus rotundus extract can be considered as a suitable candidate for the treatment and prevention of periodontitis and tooth decay

In Vitro Evaluation of Antimicrobial, Antioxidant, and Cytotoxic Effects of Sumac (Rhus coriaria L.)/Rose Water Mouthwash: In vitro evaluation of Sumac/Rosewater mouthwash

Objectives Mouthwashes are one of the most effective non-mechanical methods for removing bacteria from the mouth. This study aimed to assess the cytocompatibility, antimicrobial effects (compared to chlorhexidine mouthwash), and antioxidant activity of an experimental herbal mouthwash made from sumac (Rhus coriaria L.) and rose water. Methods The sensitivity of Streptococcus mutans, S. sanguinis, Staphylococcus aureus, Candida albicans, and Aggregatibacter actinomycetemcomitans to the experimental mouthwash was estimated by measuring the diameter of the inhibition zones. Additionally, the minimum inhibitory concentrations (MICs) were determined using the redox dye resazurin, as well as the minimum bactericidal/fungicidal concentrations (MBCs/MFCs) using the standard spot inoculation method. Cytotoxicity was evaluated using the methyl thiazolyl tetrazolium (MTT) assay, while antioxidant activity was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Results The MIC and MBC of the sumac mouthwash for the bacteria under study (except S. mutans) ranged from 0.13 to 16.65 mg/mL. For the yeast C. albicans, the MIC and MFC of the sumac mouthwash were determined to be 0.52 mg/mL. Furthermore, the sumac mouthwash showed no cytotoxicity and demonstrated significant antioxidant effects at various concentrations. Conclusion Sumac/rose water mouthwash, which is a safe, natural, biocompatible, and antioxidant product, may serve as a viable alternative to chemical antibacterial mouthwashes like chlorhexidine. This is particularly true when it is used in conjunction with regular oral hygiene practices over extended time periods

Eugenol-loaded mesoporous silica nanoparticles enhance the sensitivity of cisplatin against AGS human gastric adenocarcinoma cell line

Gastric cancer is one of the most common cancers with a high mortality rate worldwide. Eugenol possesses antioxidant, anti-inflammatory, antimicrobial, and anticancer properties. Mesoporous silica nanoparticles (MSN) have been promising carriers for drug delivery. This study aimed to investigate the synergism effect of free eugenol/eugenol-MSN and cisplatin on the AGS human gastric adenocarcinoma cell line. In this study, MSN was synthesized and loaded with eugenol. Cultured AGS cells were treated with different concentrations of free eugenol/eugenol-MSN individually and in combination with cisplatin. MTT assay, scratch assay, and flow cytometry were employed to assess cell viability, migration, and apoptosis. The antioxidant properties of free eugenol/eugenol-MSN and their effect on superoxide dismutase (SOD) activity were evaluated. Real-time PCR was used to study the effect of free eugenol/eugenol-MSN on the expression of metastatic pathway genes such as MMP2, MMP9, and KRAS, and some genes involved in apoptosis including caspase 3, caspase 8, and caspase 9. A synergism effect of free eugenol/eugenol-MSN and cisplatin (CI < 1) was observed. Combination therapies were significantly more effective in cell growth reduction, migration inhibition, and apoptosis induction than single treatments. Free eugenol has more potential in DPPH radical scavenging, and eugenol-MSN has more potential in increasing SOD activity. The relative expression of caspase 3, caspase 8, and caspase 9 genes in the treated cells increased compared to the control group, and the expression of MMP2, MMP9, and KRAS oncogenes decreased significantly. Eugenol loading in MSN leads to increasing the sensitivity of cisplatin against gastric cancer

Evaluation of surface energy and surface stability and adherence of Candida albicans to octa fluoro pentyl (meth) acrylate-coated PEEK using plasma spray

Background: Polyetheretherketone (PEEK) has favorable properties that make it able to be used as a denture base material, but it is also susceptible to the adhesion of microorganisms. In this study, we applied Octafluoropentyl (meth) acrylate (OFPA) coating on the PEEK polymer surface by using plasma spray and investigated the functional groups present on the surface, changes in the surface energy and Candida albicans adhesion. Materials and Methods: In this experimental study, the samples were placed in a control group without surface preparation and three experimental groups that were subjected to plasma spray for 10, 30, and 60 s and then impregnated with degassed Octa fluoropentyl (meth) acrylate (Sigma-Aldrich, USA) monomer. Fourier transform infrared spectroscopy (FTIR) was used to identify the functional groups and new chemical bonds between PEEK and OFPA, and Sessile Drop Method was used to evaluate the surface’s wettability. The surface morphology was checked using a LEXT OLS4000 (Olympus®-Japan) microscope, and the inhibition of C. albicans adhesion was also checked by counting the colonies in terms of colony forming unit/mL (CFU/mL). Kurskal–Wallis analysis was conducted to assess Candida adhesion, while wettability was evaluated using analysis of variance and post hoc analyses. The level of statistical significance was set at P < 0.05. Results: FTIR analysis confirmed that a chemical between OFPA and PEEK was established. The samples showed a significant increase in the contact angle after 30 s of plasma application (CA = 88.2 ± 7.3). The contact angle decreased again by increasing the surface modification to 60 s (CA = 64.33 ± 5.5). Examining the surface morphology of the samples shows an increase in surface roughness with increasing plasma time up to 60 s. The number of adherent colonies was the lowest in 30 s group, but it was not statistically significant (P = 0.658). Conclusion: No statistically significant difference in C. albicans CFU/mL count was found between groups. The contact angle of the 30 s group was significantly higher than the control group

Comparison of the bactericidal efficacy of photodynamic therapy, 2.5% sodium hypochlorite, and 2% chlorhexidine against Enterococcous faecalis in root canals; an in vitro study

Background : Enterococcus faecalis has been widely used as a valuable microbiological pathogen for in vitro studies due to its ability to successfully colonize the root canal in a biofilm-like style, invade dentinal tubules, and resist endodontic treatment procedures.The aim of this study was to compare the bactericidal efficacy of photodynamic therapy (PDT), 2% chlorhexidine, 2.5% NaOCl, and combination of PDT and 2.5% NaOCl against E. faecalis. Materials and Methods: Sixty single-rooted teeth had their canals contaminated with E. faecalis in brain heart infusion broth and were incubated for 48 hours.The canals were then subjected to 2% chlorhexidine, 2.5% NaOCl, PDT (red light emitting diode 625 nm+ Toludine Blue) and PDT + 2.5% NaOCl. Controls consisted of no treatment (positive control) and without inoculation of bacterium (negative control). Following treatment, the canal contents were sampled with sterile paper points.The samples were dispersed in transport medium, serially diluted, and cultured on blood agar to determine the number of colony forming units (CFU). Data were analyzed by Mann-Whitney U test at 5% significance level. The significance level for all analyses was set at P <.05. Results: Combination of PDT and 2.5% NaOCl achieved maximum reduction in recovered viable bacteria, no viable bacteria was observed after treatment of PDT + 2.5% NaOCl. Conclusion: Combination of PDT and 2.5% NaOCl simultaneously is effective in the elimination of E. faecalis from dentinal tubules under the conditions of this study