Precipitation of calcium compounds onto rock surfaces in water with cementitious material

In this study, the precipitation of minerals onto rock surfaces was investigated to consider whether sealing of pores and cracks in rock can be accelerated. Cylindrical specimens were prepared and then kept in purified water with powders of high-strength and ultra-low-permeability concrete (HSULPC), which will be used to confine transuranic wastes in Japan. Then, the rock specimens were weighed and the surfaces of rock specimens were inspected under a microscope. It was recognized that precipitation occurred on the surface of the rock specimens. It was also shown that precipitation did not occur on rock specimens kept in water without HSULPC. The weight of all specimens stored in HSULPC increased, and the observed weight change was larger for rocks with higher porosities. It is concluded that precipitation of minerals occurs on the rock surface when the rock is kept in water with HSULPC powders. From the results obtained in this study, it is suggested that the sealing of pores and cracks in rock can be accelerated by the precipitation of calcium compounds using HSULPC. It is concluded that HSULPC is useful for underground radioactive waste disposal

Solitary myofibroma of the mandible in an adult with magnetic resonance imaging and positron emission tomography findings: a case report

Myofibroma is a benign tumor composed of myoid spindle cells. The prevalence of myofibroma in the oral cavity is very low, with the mandible being the most common site. This report describes an adult case of myofibroma that arose on the mandible and includes magnetic resonance imaging (MRI) and positron emission tomography (PET) findings. On the MRI T1-weighted images, the tumor appeared with signal iso-intensity and was highly and heterogeneously enhanced with contrast material. On the T2-weighted images, it appeared with increased signal intensity. (18) F-fluorodeoxyglucose (FDG)-PET imaging showed abnormal strong accumulation of FDG in the left mandibular region. The tumor was removed by marginal resection of the left mandible under general anesthesia. Histopathological findings revealed that the tumor stroma contained abundant thin-walled vessels. The postoperative course was uneventful, and we found no evidence of recurrence at the postoperative 34-month follow-up

Orthodontic Management of the Edentulous Space Caused by Surgical Removal of a Large Dentigerous Cyst

Herein, we report the orthodontic management of a patient with excessive bone and permanent tooth loss after surgical cyst removal. The patient was a 13-year-old Japanese boy who was referred to our department by an oral surgeon. He had an edentulous space with alveolar bone loss and loss of 2 permanent molars in the left mandibular region, following surgical removal of a large dentigerous cyst. We decided to close this space orthodontically. First, we moved the left mandibular second premolar into the edentulous region and autotransplanted the left maxillary lateral incisor in the adjacent distal space. We then performed comprehensive orthodontic treatment to establish stable occlusion. Following treatment, functional and stable occlusion of all permanent teeth was achieved without any spaces. The findings from this case suggest that orthodontic treatment is effective in growing patients with edentulous spaces and alveolar bone loss

Long-Term Outcome of Autotransplantation of a Complete Root Formed a Mandibular Third Molar

Autogenous tooth transplantation is a procedure to reposition an autogenous tooth to another extraction area or surgically created recipient site. The autotransplantation procedures have been documented well in the literature, and the survival rate of the transplanted teeth was reported to be more than 90% after ten years. Therefore, autotransplantation might have been overlooked as a treatment option. The purpose of this case report is to evaluate the long-term (29-year) success and periodontal stability of the tooth autotransplantation from the mandibular third molar to the second molar. A 24-year old female presented to a clinic with a large caries lesion with periapical radiolucnecy on to tooth #18. The tooth was extracted with the site and treated with autogenous tooth transplantation from #17 with a complete root form. Endodontic treatment was completed 3 months post autotransplantation; the final prosthesis was placed 6 months postoperatively. The patient has shown excellent oral hygiene care and high compliance with the regular maintenance recall program. The transplanted tooth has been still functioning without any symptoms. Radiographic and clinical examinations revealed stable periodontal and endodontic conditions over the 29 years after the procedure. This case report showed the long-term success of autotransplantation of the mandibular third molar with a closed root apex to the second molar site. Autotransplantation can be an option when an adequate donor site is available to reconstruct the occlusion after the tooth extraction

Long-term stability of the inversion process for sugar and ethanol production in an existing Japanese sugar mill

In order to utilize sugarcane with a high reducing-sugar content as the raw material for sugar production, a new technology called the ‘inversion process’ has been developed. This new technology aims to enhance raw sugar yield via removal of reducing sugars through selective ethanol fermentation using an invertase-defective yeast, prior to sugar crystallization. To assess the feasibility of the inversion process technology in an existing sugar mill, a test of continuous and repeated-batch fermentation using clear juice was undertaken at a pilot-scale facility at the Shinko Sugar Mill in Japan. Batch fermentation trials were performed at 35°C for 1.5-3 h and repeated 70 times in a 2000 L fermenter using the same culture of invertase-defective yeast strain GYK-10. To confirm the long-term stability of the selective fermentation, the concentrations of saccharides and ethanol in the fermenter were measured every hour and the residual sucrose ratio and the reducing sugars removal ratio were calculated. Each batch was checked for the presence of contaminating bacteria. The results showed that 88.4% of reducing sugars were converted to ethanol and 99.5% of sucrose remained throughout the 70 consecutive batch fermentations. This indicates that the saccharometabolism selectivity of GYK-10 is stable. Although contamination by some microorganisms, such as Clostridium beijerinckii, Bacillus simplex, and Bacillus brevis, was observed, this had little influence on the fermentation outcomes. This paper reports on the feasibility of using the inversion process in an existing sugar mill