Magnetic relaxation in the 110 K superconducting phase in Bi-Sr-Ca-Cu-O thin films

We have investigated the time dependence of remnant moment decay in a highly oriented, nearly single high T(sub c) phase Bi-Sr-Ca-Cu-O thin film. A strictly logarithmic time dependence was observed over a 20 K temperature range for observation intervals of 2000 seconds. The normalized decay rate exhibits a peak around 14 K and has a relatively weak magnetic field dependence. These data are then compared with existing data on the YBCO and Eu-based superconductors

Study on the Utilization of Pyrrhotite Principally Composed of Iron and Sulfur. II : On Making Sulfuric Acid from the Roasting Gases of Pyrrhotite

Considering the results obtained in the preceding paper, the pyrrhotite, mesh of which is 28\u27\u27～32\u27\u27, was roasted at 700℃ using a baby rotary furnace, and from the roasting gases sulfuric acid was made by the contact process. Finally, the following results may be stated : - 1. As for our contact process for making sulfuric acid, the most favourable conditions are as follows : - (1) The sulfur dioxide concentration is 7～7.5%. (2) The temperature of catalyser is about 440℃. 2. The pyrrhotite cinders, which are obtained in roasting 75～120g. of ores (28\u27\u27～32\u27\u27) for 30～48 hours at 700℃ in a baby rotary furnace, contain residual sulfurs, which amount to 0.2～0.4%, and are sufficiently available for iron making

Study on the Utilization of Pyrrhotite Principally Composed of Iron and Sulfur. I : On the Roasting of Pyrrhotite

Adopting the roasting process for the utilization of pyrrhotite, studies were made of the reciprocal relations among oxidation velocity, oxidation ratio, residual sulfurs in the cinders and production ratio of sulfur trioxide in roasting gases, under the several following conditions : - (1) Flow of air (cc/min/2g) : 100, 150, 300, 500 and 1000. (2) Mesh of ore : 150\u27\u27?170\u27\u27, 48\u27\u27?50\u27\u27, 20\u27\u27?24\u27\u27, 14\u27\u27?16\u27\u27, 9\u27\u27?10\u27\u27 and 7\u27\u27?8\u27\u27. (3) Roasting temperature (℃) : 600, 650, 700, 800 and 900. (4) Roasting time : Below 200 min. The most favourable conditions were confirmed as follows : - 1. The temperature range favourable for roasting is 700°?800℃. 2. In the range described above, sufficiently great oxidation ratios are obtained in the roasting time within one hour up to the mesh of 20\u27\u27?24\u27\u27, even in case of 100cc/min/2g. 3. The cinders, roasted in such a condition as described above, contain residual sulfurs which have become under 0.2%, and are sufficiently available for iron-making

Regulation of Cell Survival and Death Signals Induced by Oxidative Stress

Oxidative stress stimulates two opposite signaling pathways leading to cell death and cell survival. Preferential selection of survival signals leads to the protection of cells against damage induced by reactive oxygen species, whereas preferential acceleration of death signals can be used to advantage in tumor therapy with oxidizing agents such as ionizing radiation and anticancer drugs. In vitro and in vivo experiments using cultured mammalian cells and experimental animals showed that ERK was included in survival signals and SAPK and p38 MAPK in death signals in oxidative stress. The activation of SAPK/JNK and subsequent expression of death receptor Fas on the cell surface caused the induction of cell death. The results mean that the acceleration of the activation of SAPK/JNK might lead to the enhancement of cell death by oxidizing agents like ionizing radiation and anticancer drugs. In fact, when cultured mammalian cells were exposed to ionizing radiation with 2-nitroimidazole derivatives having electrophilicity, the lethal effect of ionizing radiation was found to be enhanced together with the activation of SAPK/JNK and the enhancement of Fas expression. The activation of both survival and death signals was suppressed by the antioxidants N-acetylcystein and Trolox, suggesting that both signaling pathways are redox-regulated

Prolongation of total permissible circulatory arrest duration by deep hypothermic intermittent circulatory arrest

AbstractObjective: We determined whether the duration of permissible circulatory arrest could be prolonged by deep hypothermic intermittent circulatory arrest. Methods: Twenty-five beagles were cooled on bypass to 18° C to initiate deep hypothermia that was maintained for 3 hours. Five protocols were then studied: group 1, uninterrupted bypass during hypothermia; group 2, arrest for 40 minutes during hypothermia; group 3, arrest for 60 minutes during hypothermia; group 4, arrest for 80 minutes during hypothermia; and group 5, intermittent circulatory arrest, consisting of six cycles of 20 minutes of arrest followed by 10 minutes of systemic recirculation during hypothermia (total, 120 minutes of arrest). The oxyhemoglobin concentration in the brain was measured with near infrared spectrophotometry. Results: In groups 2, 3, and 4, the oxyhemoglobin concentration in the brain decreased continuously after arrest, finally reaching a plateau after 24.9 ± 1.2 minutes. This finding suggested that the available cerebral oxyhemoglobin was depleted. In contrast, the available cerebral oxyhemoglobin was not depleted during hypothermic intermittent arrest in group 5. The mitochondrial respiratory control index was significantly lower in group 4 than in the other groups (p < 0.05). However, there were no significant differences in the respiratory control index for groups 1, 2, 3, and 5. Moreover, the formation of brain edema was significantly lower in group 5 than in the other groups (p < 0.05). Conclusions: These results indicate that deep hypothermic intermittent arrest can increase the duration of total permissible circulatory arrest and will be a useful modality when prolonged arrest is anticipated. (J Thorac Cardiovasc Surg 1998;116:163-70

Data on melanin production in B16F1 melanoma cells in the presence of emu oil

AbstractHere, we present data on the effects of emu oil, obtained from emu (Dromaius novaehollandiae) fat deposits, on melanogenesis in B16F1 murine melanoma cells. The cells were cultured in media containing different concentrations of emu oil, and the melanin content of these cells was measured using a microplate reader. Next, melanin content was measured for cells cultured with α-melanocyte-stimulating hormone. This article reports the different melanin contents as μg melanin/mg cellular protein, by using bar graphs with error bars. The present data imply that emu oil reduces the cellular melanin production

A Novel Serum-Free Monolayer Culture for Orderly Hematopoietic Differentiation of Human Pluripotent Cells via Mesodermal Progenitors

Elucidating the in vitro differentiation of human embryonic stem (ES) and induced pluripotent stem (iPS) cells is important for understanding both normal and pathological hematopoietic development in vivo. For this purpose, a robust and simple hematopoietic differentiation system that can faithfully trace in vivo hematopoiesis is necessary. In this study, we established a novel serum-free monolayer culture that can trace the in vivo hematopoietic pathway from ES/iPS cells to functional definitive blood cells via mesodermal progenitors. Stepwise tuning of exogenous cytokine cocktails induced the hematopoietic mesodermal progenitors via primitive streak cells. These progenitors were then differentiated into various cell lineages depending on the hematopoietic cytokines present. Moreover, single cell deposition assay revealed that common bipotential hemoangiogenic progenitors were induced in our culture. Our system provides a new, robust, and simple method for investigating the mechanisms of mesodermal and hematopoietic differentiation