Neutron transport calculations have been carried out to assess the capability of zirconium borohydride (Zr(BH
4)
4) and zirconium hydride (ZrH
2) as advanced shield materials, because excellent ...shields can be used to protect outer structural materials from serious activation. The neutron shielding capability of Zr(BH
4)
4 is lower than ZrH
2, even though the hydrogen density of Zr(BH
4)
4 is slightly higher than that of ZrH
2. High-Z atoms are effective in neutron shielding as well as hydrogen atoms. The combination of steel and Zr(BH
4)
4 can improve the neutron shielding capability. The combinations of (Zr(BH
4)
4
+
F82H) and (ZrH
2
+
F82H) can reduce the thickness of the shield by 6.5% and 19% compared to (water
+
F82H), respectively. The neutron flux for Zr(BH
4)
4 is drastically reduced in the range of neutron energy below 100
eV compared to other materials, due to the effect of boron, which can lead to a reduction of radwaste from fusion reactors.
We have proposed a surrounding environmental recognition method using conical scanning distance measurement for mobile robots. The conical scanning method has a high robustness against ambient light ...noise and its calculation cost is low. This report describes the principle of this method and the two implementations. The first application is the quadrupedal wheeled robot. The robot can recognize a stair in sight, approach to it and climb. A second application is the indoor-outdoor wheeled mobile robot. The robot can recognize its position and obstacles on floor from information of a laser range finder and a 3D ToF camera. The validity of this method was confirmed by these robotic applications.
In a care facility, it is one of the factors that the burden of a caregiver is increasing by guiding many cared persons in a wheelchair before and after a meal. Although many autonomous electric ...wheelchairs have been researched and developed, it is not reasonable to introduce them for the entire care receivers in a nursing home from the viewpoint of cost, time and trouble of maintenance. We are developing a detachable robot that makes a manual wheelchair run autonomously. This paper describes the basic concept, target specifications and design conditions of the experimental machines and feasibility study about the localization by using the optical flow sensor. In the future, we will proceed with the implementation of the autonomous driving function.
Heat-treated lactic acid bacteria is added to some foods because it is easier to store and transport, and have less interference with other food ingredient compared with living lactic acid bacteria. ...We have reported that oral administration of heat-treated Lactobacillus crispatus KT-11 strain (KT-11) suppressed the symptoms of periodontal disease in mice orally infected with Porphyromonas gingivalis. However, the preventive effect of KT-11 on periodontal disease in human is unclear. The aim of this randomised double-blind clinical trial was to examine the effects of KT-11 consumption on the oral environment in healthy volunteers. Sixteen healthy volunteers were randomly assigned to two groups (KT-11 or placebo), and they consumed a KT-11 food tablet (1.2×1010 KT-11 cells) or a placebo food tablet (without KT-11) every day for 4 weeks. Clinical parameters including numbers of major periodontopathic bacteria in saliva, plaque score, gum conditions, and oral mucosal fluid level were evaluated at weeks 0 and 4. Amount of change in P. gingivalis numbers decreased in the KT-11 group compared to that in the placebo group at week 4. Female participants in the KT-11 group had decreased plaque scores, reddish tinge, and gingival swelling scores compared to those in the placebo group at week 4. Furthermore, male participants in the KT-11 group demonstrated increased oral mucosa fluid scores. These clinical findings suggest that daily KT-11 intake can prevent periodontal disease through the improvement of oral conditions.
Abstract The progress of fracture healing is directly related to an increasing stiffness and strength of the healing fracture. Similarly the weight bearing capacity of a bone directly relates to the ...mechanical stability of the fracture. Therefore, assessing the progress of fracture repair can be based on the measurement of the mechanical stability of the healing fracture. However, fracture stability is difficult to assess directly due to various obstacles of which shielding of the mechanical properties by the fracture fixation construct is the most relevant one. Several assessment methods have been proposed to overcome these obstacles and to obtain some sort of mechanical surrogate describing the stability of the fracture. The most direct method is the measurement of the flexibility of a fracture under a given external load, which comprises the challenge of accurately measuring the deformation of the bone. Alternative approaches include the measurement of load share between implant and bone by internal or by external sensors. A direct 3 dimensional measurement of bone displacement is provided by radiostereometric analysis which can assess fracture migration and can detect fracture movement under load. More indirect mechanical methods induce cyclic perturbations within the bone and measure the response as a function of healing time. At lower frequencies the perturbations are induced in the form of vibration and at higher frequencies in the form of ultrasonic waves. Both methods provide surrogates for the mechanical properties at the fracture site. Although biomechanical properties of a healing fracture provide a direct and clinically relevant measure for fracture healing, their application will in the near future be limited to clinical studies or research settings.
The lungs are dually perfused by the pulmonary artery and the bronchial arteries. This study aimed to test the feasibility of dual‐perfusion techniques with the bronchial artery circulation and ...pulmonary artery circulation synchronously perfused using ex vivo lung perfusion (EVLP) and evaluate the effects of dual‐perfusion on posttransplant lung graft function. Using rat heart‐lung blocks, we developed a dual‐perfusion EVLP circuit (dual‐EVLP), and compared cellular metabolism, expression of inflammatory mediators, and posttransplant graft function in lung allografts maintained with dual‐EVLP, standard‐EVLP, or cold static preservation. The microvasculature in lung grafts after transplant was objectively evaluated using microcomputed tomography angiography. Lung grafts subjected to dual‐EVLP exhibited significantly better lung graft function with reduced proinflammatory profiles and more mitochondrial biogenesis, leading to better posttransplant function and compliance, as compared with standard‐EVLP or static cold preservation. Interestingly, lung grafts maintained on dual‐EVLP exhibited remarkably increased microvasculature and perfusion as compared with lungs maintained on standard‐EVLP. Our results suggest that lung grafts can be perfused and preserved using dual‐perfusion EVLP techniques that contribute to better graft function by reducing proinflammatory profiles and activating mitochondrial respiration. Dual‐EVLP also yields better posttransplant graft function through increased microvasculature and better perfusion of the lung grafts after transplantation.
This study explores a method of bronchial artery perfusion during ex vivo lung perfusion in pursuit of better preserving microcirculation in lung grafts for long‐term transplant outcomes.
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