Prediction of the Fracture Location by Tensile Tests of Gray Cast Iron Based on the Dimensional Changes of Graphite Flakes

Gray cast iron has been used as a component in various mechanical parts, such as the blocks and heads of automobile and marine engines, cylinder liners for internal combustion engines, and machine tool bases. It is desirable because of its good castability and machinability, damping characteristics, and high performance-to-cost ratio. On the other hand, weak graphite flakes present in gray cast iron serve as stress concentrators and adversely affect the material strength. Therefore, it is crucial to examine the relationship between the distribution of graphite flakes and the strength or fracture of gray cast iron. In this study, tensile tests on gray cast iron were carried out using a plate specimen and observed by scanning electron microscopy, and the microscopic deformation was observed on the specimen surface. Particularly, the change in the size of graphite flakes during the tensile tests was examined, and the observed trend was discussed. The experimental results reveal that the dimensional changes in the graphite flakes vary in the observed area and that the final fracture occurs in an area where a large dimensional change is observed, suggesting that the fracture location or critical parts of gray cast iron can be predicted from the dimensional changes of the graphite flakes at an early stage of deformation

Finite Element Study of the Effect of Internal Cracks on Surface Profile Change due to Low Loading of Turbine Blade

Turbine blades for thermal power plants are exposed to severe environments, making it necessary to ensure safety against damage, such as crack formation. A previous method detected internal cracks by applying a small load to a target member. Changes in the surface properties of the material were detected before and after the load using a digital holographic microscope and a digital height correlation method. In this study, this technique was applied in combination with finite element analysis using a 2D and 3D model simulating the turbine blades. Analysis clarified that the change in the surface properties under a small load varied according to the presence or absence of a crack, and elucidated the strain distribution that caused the difference in the change. In addition, analyses of the 2D model considering the material anisotropy and thermal barrier coating were conducted. The difference in the change in the surface properties and strain distribution according to the presence or absence of cracks was elucidated. The difference in the change in the top surface height distribution of the materials with and without a crack was directly proportional to the crack length. As the value was large with respect to the vertical resolution of 0.2 nm of the digital holographic microscope, the change could be detected by the microscope

Lobectomy for lung cancer with a displaced left B1 + 2 and an anomalous pulmonary vein : a case report

Background: A displaced left B1 + 2 accompanied by an anomalous pulmonary vein is a rare condition involving complex structures. There is a risk of unexpected injuries to bronchi and blood vessels when patients with such anomalies undergo surgery for lung cancer. Case presentation: A 59-year-old male with suspected lung cancer in the left lower lobe was scheduled to undergo surgery. Chest computed tomography revealed a displaced B1 + 2 and hyperlobulation between S1 + 2 and S3, while the interlobar fissure between S1 + 2 and S6 was completely fused. Three-dimensional computed tomography (3D-CT) revealed an anomalous V1 + 2 joining the left inferior pulmonary vein and a branch of the V1 + 2 running between S1 + 2 and S6. We performed left lower lobectomy via video-assisted thoracic surgery, while taking care with the abovementioned anatomical structures. The strategy employed in this operation was to preserve V1 + 2 and confirm the locations of B1 + 2 and B6 when dividing the fissure. Conclusion: The aim of the surgical procedure performed in this case was to divide the fissure between S1 + 2 and the inferior lobe to reduce the risk of an unexpected bronchial injury. 3D-CT helps surgeons to understand the stereoscopic positional relationships among anatomical structures

胆道閉鎖症における肝門部リンパ節への制御性T細胞の集簇

筑波大学 (University of Tsukuba)201

Cancer organoid applications to investigate chemotherapy resistance

In clinical practice, a large proportion of cancer patients receive chemotherapy, yet tumors persist or acquire resistance; removing this obstacle could help to lower the number of cancer-related fatalities. All areas of cancer research are increasingly using organoid technology, a culture technique that simulates the in vivo environment in vitro, especially in the quickly developing fields of anticancer drug resistance, drug-tolerant persisters, and drug screening. This review provides an overview of organoid technology, the use of organoids in the field of anticancer drug resistance research, their relevance to clinical information and clinical trials, and approaches to automation and high throughput