A study of mechanochemical reactions of spin traps in hydrocarbon polymers

The identification and quantification of spin adducts and their reduction products (>NOH, >NOR) formed from nitroso compounds and nitrones in EPR and PP during spin trapping techniques have been examined. The nitroxyl yield and polymer bound nitroxyl percentage formed from these spin traps were found to be strongly dependent on the nature of spin trap and radical generator, processing temperature, and irradiation time. The nitroxyl yield and % bound nitroxyl of the spin traps improved significantly in the presence of Trigonox 101 and 2-0H benzophenone. The effect of these spin traps used as normal additive and their spin adducts in the form of EPR-masterbatch on the photo and thermal-oxidation of PP have been studied. Aliphatic nitroso compounds were found to have much better photo-antioxidant activity than nitrones and aromatic nitroso compounds, and their antioxidant activity improved appreciably in the presence of, a free radical generator, Trigonox 101, before and after extraction. The effect of heat, light and oxidising agent (meta-dichloro per benzoic acid) on the nitroxyl yield of nitroso tertiary butane in solution as a model study has been investigated and a cyclic regenerative process involving both chain breaking acceptor and chain breaking donor process has been proposed

A New Hybrid Method of IPv6 Addressing in the Internet of Things

Humans have always been seeking greater control over their surrounding objects. Today, with the help of Internet of Things (IoT), we can fulfill this goal. In order for objects to be connected to the internet, they should have an address, so that they can be detected and tracked. Since the number of these objects are very large and never stop growing, addressing space should be used, which can respond to this number of objects. In this regard, the best option is IPv6. Addressing has different methods, the most important of which are introduced in this paper. The method presented in this paper is a hybrid addressing method which uses EPC and ONS IP. The method proposed in this paper provides a unique and hierarchical IPv6 address for each object. This method is simple and does not require additional hardware for implantation. Further, the addressing time of this method is short while its scalability is high, and is compatible with different EPC standards

Comparing Effect of Safranal and Diazepam in Reducing Preoperative Anxiety and Improving Vital Symptoms

Aim: Preoperative anxiety is an unpleasant manner created by fear of surgery. The aim of the present study was to compare the effects of diazepam pill with Safranal in reducing preoperative anxiety and improving vital symptoms. Material and Methods: In this double blind randomized clinical trial, 54 patients who were candidates of urology surgery (varicocele) in 15th Khordad Hospital, Gonabad, Iran, were selected by purposive sampling method, using a randomized numbers table; they were divided into intervention (n=29) and control group (n=25). The patients in intervention group received 15mg Safranal and the patients in control group received 5mg oral diazepam 3 hours before surgery. The State-Trait Anxiety Inventory (STAI) questionnaire was completed by the patients prior to the intervention and just at the entrance to the surgery room, and the vital symptoms of the patient were evaluated. The data were analyzed by SPSS 11.5 software, using of Chi-square and independent sample t-test. Findings: After intervention, the trait anxiety in the Safranal group was significantly lower than diazepam group (p=0.007) and before the intervention (p=0.002). Also, diastolic blood pressure decreased significantly in the Safranal group compared with the diazepam group (p=0.049). Conclusion: Saffranal consumption before surgery is more effective than diazepam consumption in reducing the trait anxiety, but it does not affect state anxiety. Also, compared to diazepam, Saffranal consumption leads to a more reduction in diastolic blood pressure, while it does not affect systolic blood pressure and heart rate

Pyknodysostosis: A Case Report

Pyknodysostosis is a rare bone disease that has autosomal dominant trait. It is character-ized by short stature, diffuse osteosclerosis, acro-osteolysis, finger, and nail abnormalities. Other features include open fontanelles and sutures, relative proptosis and obtuse man-dibular gonial angle with relative mandibular prognathism. Intraoral features such as den-tal abnormalities also have been reported.In this report, a case of pyknodysostosis in a 9-year-old boy is presented. Most of the ob-served features were comparable to the other case reports but some findings such as re-peated chest infection, sleep apnea, kyphosis, scoliosis, root shortness, pulp narrowing, supernumerary and hypodontia could not be observed in this case.Instead, in this patient features such as anterior open bite and decreased anterior tooth dis-play, not reported in other cases, was evident

Esthetic effect of the buccal corridor size and amount of tooth-gingival display on smile attractiveness in two student population

3- Dentist   Background and Aims: An attractive, well-balanced smile is a paramount treatment objective of the modern orthodontic therapy. The purpose of this study was to determine the effects of the buccal corridor size and tooth-gingival display on the smile esthetics as perceived by two groups of the students.   Materials and Methods: A colored image of a woman frontal posed smile was selected. The image was altered digitally to produce different buccal corridor sizes (6%, 12.5% and 20%) and different tooth-gingival displays (maxillary central incisors and 2 mm of gingival, maxillary central incisors and dental papilla and 80% of the maxillary central incisors). The different buccal corridor sizes and tooth-gingival displays were combined to produce 9 images. These altered images were rated by 120 medical and dental students using Visual Analogue Scale (VAS). Data were analyzed using Mann-Whitney test, Pairwise comparison LSD test, Repeated measure MANOVA and ICC (Intraclass Correlation Coefficient).   Results: The smile which had the buccal corridor size of 12.5% and complete incisor display without gingival display received the highest rates among the nine smile images in the dental students group. But in the medical students group the smile with the buccal corridor size of 12.5% and 2 mm gingival display, received the highest rates among the nine smile images. There was no significant difference in judging between the male and female raters for the both groups (P>0.05). The dental students were more critical about the increasing of the gingival display.   Conclusion: In the treatment procedure that may lead to the combination of wide buccal corridor and more tooth-gingival show, more caution should be considered

Assessment of the changes in alveolar bone quality after fixed orthodontic therapy: A trabecular structure analysis

Background. Tooth displacement changes the periodontium. The aim of orthodontic treatment is desired tooth movement with minimum side effects on the alveolar bone quality. The aim of the present study was to assess changes of alveolar trabeculation in children, young adults and adults and the two genders. Methods. In this cross-sectional study, 63 patients who had been treated in Department of Orthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran, were chosen with convenient sampling method. They were divided into three groups based on their age. Their digitized panoramic radiographs (PRs) were evaluated at six interdental sites from the mesial aspect of the mandibular second molars to the distal aspect of the mandibular first premolars using a visual index. The trabeculation pattern was assigned as either dense (score 3), dense-sparse (score 2) or sparse (score 1). Data were imported to SPSS. Mean of the scores before treatment (score B) and mean of them after treatment (score A) were compared for each group with paired t-test. Changes between score B and sore A of the groups were compared using one-way ANOVA and post hoc tests. Results. Mean score A was significantly higher than mean score B in children (P = 0.001). In contrast, mean score A was significantly lower than mean score B in young adults (P = 0.003). Conclusion. Orthodontists should be cautious when treating young adults and adults regarding the probable, yet possibly temporary, negative effects of orthodontic therapy on the alveolar bone quality