Joining of ADC12 and SS400 by means of friction stir welding

For conserving the earth's environment through the reduction of energy consumption in the field of transport machinery, reduction in weight is necessary and hence the application of light materials to structural members has been investigated. For the most representative example of transport machinery, it is highly likely that a variety of aluminium materials will be used for automobile bodies. However, since iron and steel materials are still used for the main part of the structure that requires high strength, joining of dissimilar metals, i.e. aluminium and iron and steel materials, is the new technical task in terms of reducing weight.     

Nano-strip grating lines self-organized by a high speed scanning CW laser

After a laser annealing experiment on Si wafer, we found an asymmetric sheet resistance on the surface of the wafer. Periodic nano-strip grating lines (nano-SGLs) were self-organized along the trace of one-time scanning of the continuous wave (CW) laser. Depending on laser power, the nano-trench formed with a period ranging from 500 to 800 nm with a flat trough between trench structures. This simple method of combining the scanning laser with high scanning speed of 300 m min(-1) promises a large area of nanostructure fabrication with a high output. As a demonstration of the versatile method, concentric circles were drawn on silicon substrate rotated by a personal computer (PC) cooling fan. Even with such a simple system, the nano-SGL showed iridescence from the concentric circles.     

Effect of Hypoxia on Pulmonary Endothelial Cells from Bleomycin-Induced Pulmonary Fibrosis Model Mice

Pulmonary fibrosis is a progressive and fatal disorder characterized by dysregulated repair after recurrent injury. Destruction of the lung architecture with excess extracellular matrix deposition induces respiratory failure with hypoxia and progressive dyspnea. The impact of hypoxia on pulmonary endothelial cells during pulmonary fibrogenesis is unclear. Using a magnetic-activated cell sorting system, pulmonary endothelial cells were isolated from a mouse model of pulmonary fibrosis induced by intratracheally administered bleomycin. When endothelial cells were exposed to hypoxic conditions, a hypoxia-inducible factor (HIF)-2α protein was detected in CD31- and α-smooth muscle actin (SMA)-positive cells. Levels of plasminogen activator inhibitor 1, von Willebrand factor, and matrix metalloproteinase 12 were increased in endothelial cells isolated from bleomycin-treated mice exposed to hypoxic conditions. When endothelial cells were cultured under hypoxic conditions, levels of fibrotic mediators, transforming growth factor-β and connective tissue growth factor, were elevated only in endothelial cells from bleomycin-treated and not from saline-treated lungs. The increased expression of α-SMA and mesenchymal markers and collagen production in bleomycin- or hypoxia-stimulated endothelial cells were further elevated in endothelial cells from bleomycin-treated mouse lungs cultured under hypoxic conditions. Exposure to hypoxia damaged endothelial cells and enhanced fibrogenesis-related damage in bleomycin-treated pulmonary endothelial cells.     

A Restart Control Method for Position Sensorless PMSM Drive Systems Without Potential Transformer for Railway Vehicle Traction

This paper proposes a restart control method for position sensorless PMSM drive systems without a potential transformer for railway vehicle traction. This method can estimate the initial rotor speed and position under coasting conditions over the entire speed range. The method can also be used when the back‐EMF voltage is higher than the inverter DC link voltage. The proposed method is verified by experiments using a 200‐kW PMSM.     

In situ mRNA hybridization technique for analysis of human telomerase RNA in gastric precancerous and cancerous lesions

Telomerase, the ribonucleoprotein enzyme that elongates telomerase, is repressed in normal somatic cells but is reactivated during tumor progression. The purpose of this study was to investigate the localization of human telomerase RNA (hTR) expression in human gastric precancerous and cancerous lesions by using in situ mRNA hybridization (ISH) with avidin-biotin staining. We also examined telomerase activity in these lesions by using hybridization protection assay connected with a telomeric repeat amplification protocol (TRAP/HPA). Analyzed tissue samples were as follows; 132 cases of chronic atrophic gastritis without intestinal metaplasia, 115 incomplete-type intestinal metaplasias, 40 complete-type intestinal metaplasias, 23 hyperplastic polyps, 23 tubular adenomas and 26 adenocarcinomas. In ISH analysis, high levels of hTR expression were observed preferentially in the nuclei at the single-cell level. hTR-expressing cells in carcinomas and adenomas were significantly more frequent than those of the other lesions (P < 0.001). The expression pattern of hTR in carcinoma and adenoma tissues was heterogeneous and similar intratumor heterogeneity was detected in Ki-67 immunoreactivity. Infiltrating lymphocytes in tissue also exhibited high levels of hTR expression. In TRAP/HPA analysis, carcinomas had significantly more frequent positivity for telomerase activity and a higher level of telomerase activity than the other lesions (P < 0.05). However, the amount of telomerase activity did not parallel the expression level of hTR. Our data suggest that hTR expression increases in the early stages of stomach carcinogenesis and that sufficient synthesis of hTR is a prerequisite for telomerase reactivation in tumorigenesis.     

A case of neurologic type of Wilson's disease with increased aluminum in liver: comparative study with histological findings to metal contents in the liver

Histological findings and metal contents in the liver were studied in a patient with neurologic type of Wilson's disease. Copper and aluminum contents in the biopsied liver of the patient with Wilson's disease were measured simultaneously by neutron activation analysis at Research Reactor Institute, Kyoto University. Four cases of adult cirrhosis were selected as the control for cirrhosis and five cases of adult liver as the control for neurologically normal. The biopsied liver showed markedly increase in the copper content (814.4 micrograms/g: dry weight) and extremely high content of aluminum (479.4 micrograms/g: dry weight), compared to those of the controls. On the other hand, macroscopically no cirrhosis was observed and the characteristic appearances of macronodular cirrhosis failed to detect histologically. Interestingly the fibrosis or inflammation of the liver was seen faintly. It is likely that toxic metals in the liver such as aluminum, copper and manganese might be implicated in the pathogenesis of neurologic type of Wilson's disease.     

A case of amyloidosis of the tracheobronchial tree and inferior nasal concha

A 50-year-old man resented at a local medical clinic with nasal obstruction. He was treated but did not improve. He then consulted our institution. Chest X-ray disclosed infiltrative shadows in the basal region of the left lung. A computed tomography scan of the lung showed marked thickening of the airway walls extending from the trachea to both bronchial trees and obstructive changes in the left lower lobe of the lung. On bronchoscopic examination the bronchial mucosa was reddened and edematous with a pinhole bronchial obstruction in one region. Congo red staining of biopsy samples taken from the bronchial mucosa showed deposition of an amorphous substance. Tracheobronchial amyloidosis was diagnosed. The amyloid material was resistant to potassium permanganate and tested positive for lambda-chain of L immunoglobulin. Otorrhinolaryngological examination disclosed a tumor in the inferior nasal concha as the cause of his nasal obstruction. The nasal tumor was resected and AL lambda-type amyloidosis was diagnosed pathologically. Tracheobronchial and inferior nasal concha amyloidosis is an extremely rare pathological condition. The patient was followed for one year and remain asymptomatic without treatment.     

Effect of training program based on anaerobic threshold in the early phase after acute myocardial infarction

We devised a new physical training program on the basis of anaerobic threshold for rehabilitation in the early phase of acute myocardial infarction. Forty-four patients were divided into two groups, control and training. We measured the left ventricular ejection fraction using nuclear stethoscopy during the treadmill test and calculating radioactive cardiac output. In the training group, anaerobic threshold and exercise time to the anaerobic threshold point were significantly increased, and stroke volume at rest measured by the dye dilution method increased significantly. Radioactive cardiac output during exercise also increased after the exercise therapy. These results indicate that the rehabilitation program consisting of physical training based on the anaerobic threshold is effective.