Three-Dimensional Fabrication of Metallic Parts and Molds Using Hybrid Process of Powder Layer Compaction and Milling

In order to produce three-dimensional models with cemented carbide powders, a freeform fabrication method named Layered Compaction Manufacturing (LCM), which is a hybrid process of powder compaction and CNC milling in layer-by-layer additive manner, is proposed. The feasibility of the LCM process is confirmed by making a WC-9wt%Co carbide model. The connecting strength between the layers of the model after sintering is evaluated by the bending test. It is found that the transverse strength of the sintered products is higher than 2 GPa. A WC-9wt%Co model with inside channels for temperature control is successfully fabricated using a paraffin wax as a sacrificial material in the LCM process.Mechanical Engineerin

Waves and Drawdown Generated by River Traffic on the Illinois and Mississippi Rivers

published or submitted for publicationis peer reviewedOpe

Mechanical Properties of Pure Titanium Models Processed by Selective Laser Melting

The influence of laser processing parameters on mechanical properties and microstructure of pure titanium models made by selective laser melting is investigated. The density of the models can reach higher than 95% under proper conditions. Although the tensile strength test shows results comparable to the wrought material, the impact and torsional fatigue strengths are low because of porosity and oxygen pick-up suggested by increasing of hardness. Hot isostatic pressing allows almost full densification and greatly improves mechanical properties.Mechanical Engineerin

Modeling Retinal Degeneration Using Patient-Specific Induced Pluripotent Stem Cells

Retinitis pigmentosa (RP) is the most common inherited human eye disease resulting in night blindness and visual defects. It is well known that the disease is caused by rod photoreceptor degeneration; however, it remains incurable, due to the unavailability of disease-specific human photoreceptor cells for use in mechanistic studies and drug screening. We obtained fibroblast cells from five RP patients with distinct mutations in the RP1, RP9, PRPH2 or RHO gene, and generated patient-specific induced pluripotent stem (iPS) cells by ectopic expression of four key reprogramming factors. We differentiated the iPS cells into rod photoreceptor cells, which had been lost in the patients, and found that they exhibited suitable immunocytochemical features and electrophysiological properties. Interestingly, the number of the patient-derived rod cells with distinct mutations decreased in vitro; cells derived from patients with a specific mutation expressed markers for oxidation or endoplasmic reticulum stress, and exhibited different responses to vitamin E than had been observed in clinical trials. Overall, patient-derived rod cells recapitulated the disease phenotype and expressed markers of cellular stresses. Our results demonstrate that the use of patient-derived iPS cells will help to elucidate the pathogenic mechanisms caused by genetic mutations in RP

A unique stroke case with contralateral sulcal hyperintensity on fluid-attenuated inversion recovery image changed to linear serpiginous structures

An 83-year-old man developed acute ischemic stroke. Brain magnetic resonance imaging (MRI) showed ischemic stroke in the left parietal lobe gyri, but fluid-attenuated inversion recovery (FLAIR) showed hyperintensity in the contralateral right temporal-occipital lobe sulci. Follow-up FLAIR image showed the gradual disappearance of the sulcal hyperintensity in the sulci and changed to linear serpiginous structures. This is a unique stroke case showing transitioned FLAIR findings suggesting that the sulcal hyperintensity findings are more severe and an earlier ischemic condition than the linear serpiginous structures

Efficacy and safety of spot heating and ultrasound irradiation on in vitro and in vivo thrombolysis models

The feasibility of transcranial sonothrombolysis has been demonstrated, although little is known about the relationships between thermal or mechanical mechanisms and thrombolytic outcomes. Therefore, the present study aims to reveal the effect and safety of temperature and ultrasound through in vitro and in vivo thrombolysis models. Artificial clots in microtubes were heated in a water bath or sonicated by ultrasound irradiation, and then clots weight decrease with rising temperature and sonication time was confirmed. In the in vitro thrombotic occlusion model, based on spot heating, clot volume was reduced and clots moved to the distal side, followed by recanalization of the occlusion. In the in vivo study, the common carotid artery of rats was exposed to a spot heater or to sonication. No brain infarct or brain blood barrier disruption was shown, but endothelial junctional dysintegrity and an inflammatory response in the carotid artery were detected. The present spot heating and ultrasound irradiation models seem to be effective for disintegrating clots in vitro, but the safety of the in vivo model was not fully supported by the data. However, the data indicates that a shorter time exposure could be less invasive than a longer exposure. </jats:p

マウスのフェロモンESPファミリーが引き起こす社会行動とその神経回路基盤の解析

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 東原 和成, 東京大学教授 高橋 直樹, 東京大学准教授 高橋 伸一郎, 東京大学准教授 舘川 宏之, 理化学研究所シニアチームリーダー 吉原 良浩University of Tokyo(東京大学