The purpose of this study was to investigate the morphological change of enamel surfaces after irradiated with a femtosecond (fs) pulsed laser at 90 μJ and 20 mm/s at different conditions of focus ...(surfaces, 1 mm subsurfaces and 2 mm subsurfaces). Morphological changes of surfaces and subsurfaces were evaluated under a scanning electron microscope (SEM) and a polarized light microscope. The surface analysis under SEM demonstrated the effect of laser on enamel abrasion only on the focus at surfaces. Change at subsurfaces was observed in all specimens that were irradiated at subsurfaces by SEM. Polarized light properties of enamel demonstrated varied changes with different degrees depending on the focus conditions compared with non-irradiated surfaces. In conclusion, the fs-pulsed laser caused a change on enamel subsurfaces.
We studied whether long-term treatment using α-glucosidase inhibitor (α GI), acarbose, prevents thed evelopment of impaired glucose tolerance (IGT) into diabetes. Subjects with IGT were divided into ...2 groups matched for age, gender, and body mass index (BMI).Subjects were trained in diet therapy (2, 5 kcal/kg body weight) before the study and treated with (group A) or without (group B)α-glucosidase inhibitor (α-GI) for 6 months.Subjects underwent a 75 g oral glucose tolernce test (OGTT) with serum glucose and insulin concentration measured at 0, 60, and 120 min before and after 6 months of treatment.Insulin resistance was assessed by the homeostasis model assessment (HOMA-R) index.Serum glucose before or after glucose loading in both groups was reduced significantly after treatment.Serum glucose in group A were not significantly reduced compared to those in group B, however, the HOMA-R index of group A was more reduced than that of group B (A: 3.64±0.01 vs 2.07±0.01, B: 3.64±0.02 vs 2.86±0.01;p<0.05, before vs after), suggesting that the insulin resistance of group A was significantly improved compared to that of group B (p<0.05).Our results suggest that α GI treatment in high-risk subjects before diabetes onset prevents IGT from developing into diabetes.
As space exploration progresses, renewed attention has been given to advanced lunar exploration technologies. The main objective is to address many open questions about the Moon, such as its origin ...or chemical components, as most of the current hypotheses are just inferences based on limited evidences. Unmanned subsurface investigation technologies for the moon are of special significance for future exploration as it may enhance our knowledge of space science. This paper aims to develop a subsurface robotic explorer for the Moon in order to bury an instrument, such as a long period seismometer, for acquiring subsurface information. In previous work, the authors have showed the effectiveness of a novel screw drilling mechanism for burrowing an exploration robot with no-reaction to the body. This paper addresses anew a fundamental dynamics model for a robotic screw explorer. The model includes the geometric model of a conical screw drill and the soil mechanics, allowing us to mathematically estimate a frictional moment around the perimeter of the screw. This theoretical analysis is governed by complex soil behaviors and has not been thoroughly discussed previously. Hence, this challenging study can provide key insight into this matter. The validity of the model developed here is also presented in this paper.
The purpose of this study was to evaluate histopathologically the effect on pulp tissue of microleakage in resin composite restorations. Seventy-two class V cavities were prepared on buccal surfaces ...of monkeys and divided into 3 groups, F, O, and S. Every cavity was etched with 37% phosphoric acid. In group F cavities, each cavity was restored with photo-curable composite without any dentin adhesives. In group O, the cavities were left unfilled. In group S, each cavity was treated with a dentin adhesive system and restored with a restorative composite. After 3, 30, or 90 days, animals were sacrificed and the subjected teeth were immediately removed, then fixed and decalcified. Following sectioning and staining with hematoxylin and eosin or Taylor's modified bacteria staining, each sample was examined with a light microscope. In most teeth with group S cavities, bacterial invasion was not found indicating excellent marginal sealing. The pulpal reaction was much less than that in other groups. In group F as well as in group O, bacteria were frequently observed in the cavity; however, bacteria penetrated into dentinal tubules more in group F than in group O at 30 and 90 days. A correlation between the presence of bacteria and pulpal inflammation was strongly indicated. It was suggested that a leaky restoration was more harmful to the pulp than an open prepared cavity without restoration.
Neuromedin B and neuromedin C are novel decapeptides that have recently been isolated from porcine spinal cord and canine intestinal mucosa. We have studied the effects of neuromedin B and neuromedin ...C on insulin release from the isolated perfused rat pancreas. The effect of neuromedin B was detectable at a concentration of 10mM, and that of neuromedin C was detectable at a concentration of 1nM. Further increase in the concentration of neuromedin B and neuromedin C resulted in dose-dependent increases in insulin secretion. The effectiveness of neuromedin B and neuromedin C as insulinotropic agents depended on the glucose concentration; both were more effective at a higher concentration of glucose. However, insulinotropic effects of these peptides in the presence of 8.3mM glucose were limited to the first 3 min of a 20-min perfusion. These results, coupled with a recent study demonstrating bombesin-like immunoreactivity in nerves in the pancreas, suggest that neuromedin B and neuromedin C exert a direct local action on insulin secretion in the pancreas.
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