Water model study of horizontal molten steel-Ar two-phase jet in a continuous casting mold

A water model study was carried out to understand the behavior of a molten steel and Ar gas two-phase jet issuing out of a submerged entrance nozzle in continuous casting modls. A mixture of water and air was injected horizontally from a circular pipe settled flush with the narrow face of a mold having a rectangular cross section. The water-air two-phase jet thus generated was pulled upward through the effect of buoyancy force acting on air bubbles. The deflection of the jet in the upward direction was correlated by introducing a velocity scale, which could characterize the upward moving velocity of the jet. The mean velocity and turbulence components of water flow were measured with a laser Doppler velocimeter. Empirical equations were proposed for predicting the two velocity components.     

Start-up from the frozen state of two-phase thermosyphons

In a cold region, ethylene glycol or propylene glycol aqueous solution is usually used as a working fluid of thermosyphons, because if pure water is used as a working fluid, the thermosyphon tube breaks due to the volume expansion of ice when water freezes into ice. If a non-freeze working fluid is required, for example, under the environmental temperature of −20 °C, around 37 mass% ethylene glycol aqueous solution must be used. Usually, two-phase heat transfer coefficients of binary mixtures become lower than pure liquid. As the concentration of ethylene glycol increases, the freezing point lowers, and then the heat transfer coefficient also lowers. Therefore, if the small concentration of ethylene glycol is used, the degradation in heat transfer may be small. In the present study, 1–40 mass% ethylene glycol aqueous solutions were prepared, and they were poured into glass test tubes, respectively. These glass test tubes were immersed in ethanol of −20 °C to −40 °C, which were cooled down by a refrigerator. Consequently, the test tube with pure water was cracked and broken, but the other test tubes were not broken even in the case of 1 mass% concentration. Since the above fact was found, the start-up experiment from the frozen state of the two-phase thermosyphon was carried out using 1 and 2 mass% ethylene glycol aqueous solutions as the working fluid. As a result, it was revealed that these thermosyphons started up smoothly without any troubles.     

Present status and future perspectives on the development of bioartificial kidneys for the treatment of acute and chronic renal failure patients

A bioartificial renal tubule device (BTD) consisting of a hollow-fiber module and human proximal tubular epithelial cells has been completed technically by Humes and colleagues and a few other groups. Humes and colleagues developed BTD, treated acute kidney injury patients with multiorgan failure by continuous hemofiltration (CHF) in conjunction with BTD, and reported a significantly higher survival rate than that by CHF with BTD without cells in the Food and Drug Administration phase IIa trial. However, BTD has never been approved by the US Government, as the CHF+BTD treatment did not show a significant difference from the control group in the phase IIb trial. Human proximal tubular epithelial cells were confirmed to be overgrown on artificial membrane, which resulted in the inhibition of active transports and the metabolism of essential substances. Function of the BTD could be maintained in a U0126-contained medium, even if the BTD had to have been waited by a new acute kidney injury patient for several weeks. For wearable kidneys, heparin-covalently bound membrane or methacryloyloxyethyl phosphorylcholine (MPC) polymer-coated membranes are candidates for antithrombogenic hemofilters, while endothelial progenitor cells from a cord blood, CD133(+) cells-attached hemofilter in which the permeability of the cells was enhanced by the enlarged diameter of fenestrae by treating with cytochalasin B are another candidate. The MPC blend membrane containing 1% of the MPC polymer in polysulfone was developed as a BTD module. MPC was 7 times larger at the sponge layer than at the skin layer of the membrane, resulting in hemocompatibility at the sponge layer and cytocompatibility at the skin layer.     

Molecular characterization of the PEX14 gene from the methylotrophic yeast Pichia methanolica

In this study, we describe the molecular characterization of the PmPEX14 gene encoding the peroxisomal membrane protein from the methylotrophic yeast Pichia methanolica. The pex14Δ strain of P. methanolica lost its ability to grow on methanol and oleate but grew normally on glucose. Disruption of the PmPEX14 caused a decrease in the activities of peroxisomal methanol-metabolizing enzymes and mislocalization of those proteins into the cytosol and vacuole. Taken together, these findings show that PmPex14p has an essential physiological role in methanol metabolism in P. methanolica.     

A Study on Tribology in Minimal Quantity Lubrication Cutting

Despite the fact that minimal quantity lubrication (MQL) machining produces almost similar cutting performance to conventional flood supply machining while using much less metal working fluid (MWF), it has not been fully utilized in industry due to lack of understanding of the fundamental process physics. To take full advantage of MQL machining and expand its applicability, an understanding of its tribological behavior is critical. Hence, in this study, the adsorption characteristics of MQL media during orthogonal cutting was investigated using two experimental setups; one in a high vacuum chamber with a mass spectrometer to observe mass changes of MQL media during cutting, and another setup in an atmospheric chamber where the supply of MQL media can be controlled. The former is mainly for analysis of the tribological behavior of MQL media, and the latter for cutting performance monitoring. It was found that the adsorption amount of MQL media was closely related to lubrication behavior. Oxygen in MQL supply plays a significant role in lubrication. Ultrasonic vibration cutting tests with MQL were conducted for further understanding of lubrication mechanism.     

Lack of pharmacokinetic interaction between mexiletine and omeprazole

A neonate presented to our institution with the physical findings of coarctation of the aorta. After starting prostaglandin E1 the signs and symptoms resolved despite persistent closure of the ductus arteriosus. We present echocardiographic evidence to support the contention that a ductal tissue sling contributes to the formation of juxtaductal coarctation of the aorta.     

Bifid ribs observed in the third and the fourth ribs

The laparoscopic repair of a perforated duodenal ulcer was effectively done in two patients both of whom were poor risks for surgery. One was a 39-year-old woman with a history of bronchial asthma since she was 20 years of age, while the other was a 76-year-old man with hepatocellular carcinoma, lung cancer, and diabetes mellitus. The postoperative course of these patients was uneventful. Based on these findings, the laparoscopic repair of a perforated duodenal ulcer should thus be considered as a first choice of treatment for a perforated duodenal ulcer, even in poor-risk patients.     

Cytosolic redistribution of cytochrome c after transient focal cerebral ischemia in rats

Recent in vitro cell-free studies have shown that cytochrome c release from mitochondria is a critical step in the apoptotic process. The present study examined the expression of cytochrome c protein after transient focal cerebral ischemia in rats, in which apoptosis was assumed to contribute to the expansion of the ischemic lesion. In situ labeling of DNA breaks in frozen sections after 90 minutes of middle cerebral artery (MCA) occlusion showed a significant number of striatal and cortical neurons, which were maximized at 24 hours after ischemia, exhibiting chromatin condensation, nuclear segmentation, and apoptotic bodies. Cytosolic localization of cytochrome c was detected immunohistochemically in the ischemic area as early as 4 hours after 90 minutes of MCA occlusion. Western blot analysis of the cytosolic fraction revealed a strong single 15-kDa band, characteristic of cytochrome c, only in the samples from the ischemic hemisphere. Western blot analysis of the mitochondrial fraction showed a significant amount of mitochondrial cytochrome c in nonischemic brain, which was decreased in ischemic brain 24 hours after ischemia. These results provide the first evidence that cytochrome c is being released from mitochondria to the cytosol after transient focal ischemia. Although further evaluation is necessary to elucidate its correlation with DNA fragmentation, our results suggest the possibility that cytochrome c release may play a role in DNA-damaged neuronal cell death after transient focal cerebral ischemia in rats.