Comparison of four manikins and fresh frozen cadaver models for direct laryngoscopic orotracheal intubation training.

OBJECTIVE: To compare the acceptability and preference between manikin models and fresh frozen cadaver (FFC) for direct laryngoscopic orotracheal intubation training. METHODS: In this prospective crossover trial, participants in the airway workshop performed direct laryngoscopic orotracheal intubation on four airway training manikins: Airway Management Trainer (Ambu, St Ives, UK), Airway Trainer (Laerdal, Medical, Stavanger, Norway), Airsim (Trucorp, Belfast, Northern Ireland) and "Bill 1" (VBM, Sulz, Germany), and FFC. Participants were asked to access the following: reality of jaw mobility, difficulty with mouth opening, reality of neck flexibility, difficulty with intubation, overall model reality and model preference for each model using a visual analogue scale (VAS) of 0-10 cm. The VAS scores for each model were compared. RESULTS: Fifty-six participants were included in the study. The FFC had a highest VAS score for reality of jaw mobility, overall reality and preference of model. Trucorp manikin and Laerdal manikin followed cadaver. There were no significant statistical differences between Trucorp manikin and Laerdal manikin. In difficulty with mouth opening and difficulty with intubation, Trucorp manikin had the lowest VAS score. CONCLUSION: The FFC is a more realistic and preferred model for direct laryngoscopic orotracheal intubation training. Trucorp and Laerdal manikin can be used as alternative models.

Soil washing using various nonionic surfactants and their recovery by selective adsorption with activated carbon.

The performance of activated carbon in soil washing and subsequent selective adsorption for surfactant recovery from the washed solution was investigated. Sandy loam soil contaminated with phenanthrene at 200 mg kg(-1) was washed with four different nonionic surfactants: Tween 40, Tween 80, Brij 30 and Brij 35. The efficiency of soil washing was highest when using Brij 30 with the highest solubilizing ability for phenanthrene and low adsorption onto soil. In the selective adsorption step, surfactant recovery was quite effective for all surfactants ranging from 85.0 to 89.0% at 1 g L(-1) of activated carbon (Darco 20-40 mesh). Phenanthrene removal from the solution washed with Brij 30 was only 33.9%, even though it was 54.1-56.4% with other surfactants. The selectivity was larger than 7.02 except for Brij 30 (3.60). The overall performance considering both the washing and surfactant recovery step was effective when using Tween 80 and Brij 35. The results suggest that higher solubilizing ability of surfactants is a requirement for soil washing but causes negative effects on phenanthrene removal in the selective adsorption. Therefore, if a surfactant recovery process by selective adsorption is included in soil remediation by washing, the overall performance including the two steps should be considered for properly choosing the surfactant.

Double-blind Randomized Study to Evaluate the Safety and Efficacy of Over-the-counter Tooth-whitening Agents Containing 2.9% Hydrogen Peroxide.

OBJECTIVES: In this double-blind randomized study, we evaluated the safety and efficacy of over-the-counter (OTC) bleaching products that included 2.9% hydrogen peroxide (H2O2) with two methods of application: strip and paint-on. METHODS AND MATERIALS: A commonly used product was selected for each type (strip and paint-on) of OTC bleaching agent. In total, 75 volunteers were assigned randomly into five groups: two test groups (strip and paint-on), two negative control groups (products without H2O2), and one positive control group (dentist-supervised home bleaching). The tooth shade was evaluated with a spectrophotometer and Vita shade guide at baseline and 2 weeks and 4 weeks after use. To document any adverse reactions, such as hypersensitivity or tissue irritation, all patients were examined and the Gingival Index (GI), Plaque Index (PI), and a visual analog scale (VAS) measuring the cold response were obtained. RESULTS: There were significant differences among the five groups ( p<0.001). The positive control showed the greatest color changes; then, in decreasing order, the strip-type test group, paint-on-type test group, and negative controls. The strip-type bleaching agent was significantly more effective than the paint-on-type agent and the negative control, while it was significantly less effective than the dentist-supervised home bleaching. Regardless of the treatment group, the canines showed greater color changes than did the central or lateral incisors. Some cases of gingival irritation and hypersensitivity were observed, but they were mild and reversible. GI, PI, and VAS scores were not significantly changed. CONCLUSIONS: Within the limitations of this study, the results indicated that the strip-type and paint-on-type OTC bleaching agents were significantly less efficacious than was dentist-supervised home bleaching; however, they showed acceptable safety and efficacy. The strip-type was more effective than was the paint-on-type in this study.

Retention Improvement in Fluoride Application with Cold Atmospheric Plasma.

This study aimed to apply fluoride formulations to enamel with cold atmospheric plasma (CAP) and analyze the fluoride uptake, retention, and acid resistance quantitatively. Human enamel specimens were divided randomly into 2 groups: group APF1, 1.23% acidulated phosphate fluoride (APF) gel; group APF2, 1.23% APF gel with CAP. Fluoride and CAP were applied to the samples 4 times at 1-wk intervals. The specimens were also stored in artificial saliva for 4 wk to evaluate the retention of fluoride. The fluoride content on the fluoride-treated enamel was measured by an electron probe microanalyzer. To detect the resistance to demineralization, the calcium-to-phosphate ratio of the enamel samples was measured after the application of APF gel with or without CAP, followed by soaking in the demineralization solution. In groups APF1 and APF2, the amount of fluoride detected increased depending on the application frequency, and more fluoride was detected in group APF2 than in group APF1. In the experiment examining the maintenance effect, fluoride was not detected in group APF1, whereas fluoride was detected in group APF2 up to the fourth week. As for the resistance to demineralization, the calcium-to-phosphate ratio of the enamel treated with APF and CAP was higher than that treated with APF alone, and it increased with the frequency of treatment. This study suggests that the combination treatment of CAP and fluoride improves retention of fluoride on the enamel and resistance to demineralization when compared with treatment with fluoride alone.

Crepidiastrum denticulatum Extract Ameliorates Kidney Ischemia-Reperfusion Injury in Mice.

BACKGROUND: Crepidiastrum denticulatum (CD) is a well-known, traditionally consumed vegetable in Korea, which was recently reported to contain bioactive compounds with detoxification and antioxidant properties. Ischemia-reperfusion injury (IRI) is a major problem after renal transplantation. Furthermore, inflammatory responses to IRI exacerbate the resultant renal injury. In the present study, we investigated whether CD extract exhibits renoprotective effects against IR-induced acute kidney injury in mice. MATERIALS AND METHODS: Renal IRI was induced in male C57BL/6 mice by bilateral renal pedicle occlusion for 30 minutes followed by reperfusion for 48 hours. CD extract (75 mg/kg) was administered orally 5 days before IRI. RESULTS: Treatment with CD extract significantly decreased blood urea nitrogen and serum creatinine levels as well as kidney tubular injury. CD also prevented IRI-induced renal glutathione depletion and increased malondialdehyde levels. Western blotting and reverse transcriptase polymerase chain reaction indicated that CD extract significantly attenuates inducible nitric oxide synthase and toll-like receptor 2/4 protein levels 48 h after IRI. The expression of tumor necrosis factor-α and interleukin-1ß was significantly decreased in the CD extract treatment group. CONCLUSION: CD extract improved acute renal IRI through its antioxidant and anti-inflammatory effects. These findings suggest that CD extract is a potential therapeutic agent for acute ischemia-induced renal damage.

Oleanolic acid and ursolic acid stabilize liposomal membranes.

The effects of oleanolic acid (OA) and ursolic acid (UA) on the fluidity and stability of dipalmitoyl phosphatidylcholine (DPPC) liposomal membrane were monitored by measuring the fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene labeled in the liposomal membrane and the leakage of calcein from the probe-encapsulated liposomes. The experiments with the liposomes made of DPPC and OA or UA showed that OA and UA exhibited a moderate fluidity-modulating effect for the liquid-crystalline liposomal membrane, and a strong condensing effect for both crystalline and liquid-crystalline liposomal membranes. Their effects were comparable to those of cholesterol. These results suggest that their fluidity-modulating and condensing effects might have some implications in their biological functions.

Effect of agitation intensity on the exo-biopolymer production and mycelial morphology in Cordyceps militaris.

AIMS: The influence of agitation intensity on Cordyceps militaris morphology and exo-biopolymer production was investigated in a 5 litre stirred vessel using a six-blade Rushton turbine impeller. METHODS AND RESULTS: The mycelial morphology of C. militaris was characterized by means of image analysis, which included mean diameter, circularity, roughness and compactness of the pellets. The morphological parameters of the pellets grown under different stirring conditions were significantly different, which correspondingly altered exo-biopolymer production yields. CONCLUSIONS: The compactness of the pellets was found to be the most critical parameter affecting exo-biopolymer biosynthesis; more compact pellets were formed at 150 rev min(-1) with maximum exo-biopolymer production (15 g l(-1)). SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study suggest that morphological change of pellets is a good indicator for identifying the cell activity for exo-biopolymer production.