Role of granulosa and theca cell interactions in ovarian follicular maturation

We developed a culture system in which two types of ovarian follicular cells were allowed to attach to opposite sides of a collagen membrane. Using this in vitro cell culture system, we studied the effects of granulosa- and theca-cell interaction on the morphology, structure, and function of bovine ovarian follicular cells. In the first part of the study, we explored how the interaction between theca and granulosa cells affects the morphology and structure of the cells. This study was done using follicular cells collected from bovine ovarian follicles at the early developmental stage. Granulosa cells cultured alone were flattened, and formed a monolayer sheet. By contrast, granulosa cells cultured with theca cells were convex, and formed multilayer sheets. Theca cells cultured alone were thin, flat, and spindle-shaped. Theca cells cultured with granulosa cells were also spindle-shaped; however, they appeared convex and more densely packed when compared with theca cells cultured alone. In the second part of the study, the possible role of the cellular interaction in the control of differentiation and growth of granulosa and theca cells was investigated. When follicular cells were isolated from the early stage of follicular development, theca cells reduced progesterone and inhibin production by granulosa cells and augmented the growth of granulosa cells. When the cells were isolated from the late stage of follicular development, by contrast, theca cells augmented hormonal production by granulosa cells, and did not affect the growth of granulosa cells. The growth and androstenedione production by theca cells were increased by the presence of granulosa cells, irrespective of the origin of follicular cells. These results demonstrated that communication between two types of follicular cells results in reciprocal modulation of their morphology, structure, growth, and function. Cellular interactions seem to be one of the major factors controlling the differentiation and growth of the follicular cells during the follicular maturation process. In contrast to granulosa and theca cells cultured alone, cells in the coculture seemed to possess morphological and functional characteristics more similar to those of cells in the growing follicular wall in vivo. Thus, we speculate that the interaction between these two types of follicular cells is essential for the maintenance of original structure and function of the bovine follicular wall.     

Thermodynamics of nitrogen in CaO-SiO2-AI2O3 slags and its reaction with Fe-Csat. melts

The solubility of nitrogen as the nitride ion in CaO-SiO₂-Al₂O₃ slags in equilibrium with N₂-CO gas mixtures and carbon was measured at 1823 K. The nitride capacity (C _N3-) was calculated to compare the nitrogen contents measured under different nitrogen and oxygen potentials.C _N3- decreased with increasing basicity and by replacing SiO₂ with A1₂O₃. The nitrogen partition ratio between carbon saturated iron and the slag was measured in CO gas at one atmosphere at 1823 K. By comparing the partition ratios with the corresponding nitride capacities measured by the gas-slag experiments, it was concluded that the oxygen partial pressure at the slag-metal interface was controlled by the Fe-FeO reaction. A new definition of nitride capacity was proposed based on the reaction between nitrogen and the network former,i.e., SiO₂ or A1₂O₃. This capacity could consistently explain the experimental results. Empirical equations were derived to estimate the activity coefficients of silicon and aluminum nitrides in the slags. On leave of absence from the Research Institute of Mineral Dressing and Metallurgy, Tohoku University, Sendai, Japan.     

Study on the foaming of CaO-SiO2-FeO slags: Part I. Foaming parameters and experimental results

In order to understand the effect of slag composition on foaming in iron and steelmaking processes, slag foaming was quantitatively studied for CaO-SiO₂-FeO slags in the temperature range of 1250 °C to 1400 °C. It was found that slag foaming could be characterized by a foaming index (Σ), which is equal to the retention or traveling time of the gas in the slag, and the average foam life ( τ). The effects of P₂O₅, S, MgO, and CaF₂ on foaming were studied. As expected, slag foaming increased with increasing viscosity and decreasing surface tension. It was found that suspended second-phase solid particles such as CaO, 2CaO SiO₂, and MgO stabilized the foam and had a larger effect on foaming than changes in viscosity and surface tension for the slags studied. Kimihisa Ito, Research Associate, formerly with the Department of Metallurgical Engineering and Materials Science, Carnegie Mellon University     

The Fluorescence and Electroluminescence Properties of the Carbazole–Phenylazomethine Double Layer-Type Dendrimer

The fluorescence properties of double layer-type dendrimers with carbazole as the outer layer and phenylazomethine as the inner layer of the dendron with a zinc porphyrin core were studied. Based on the fluorescence quantum yield (solution), the effect of the bulky dendron to inhibit the interaction of the chromophores was confirmed. Additionally, the efficient light-harvesting property of the double layer-type dendron was revealed by the fluorescence measurement at several excitation wavelengths. These dendrimers were used as an emitting-layer in an OLED device. The electroluminescence of the core porphyrin was observed and it was shown that the double layer-type dendrimer with a luminescent core has the potential to be a hole-transporting/emitting material.     

Insight into the Effect of Dendrimer Structure on Photoluminescence from Assembled Bismuth Complexes

Our previous report demonstrated the fabrication and functionalization of the luminous dendrimer based on phenylazomethine-BiCl₃ complexes (Kambe et al. in Angew Chem Int Ed 55:13151, 2016). It is now revealed that the bismuth assembled phenylazomethine dendrimers have different luminous efficiencies depending on the layers of the DPAG4 by photoemission and absorption spectroscopy.     

Thermodynamics of nitrogen in CaO-SiO2-AI2O3 slags and its reaction with Fe-Csat. melts

The solubility of nitrogen as the nitride ion in CaO-SiO₂-Al₂O₃ slags in equilibrium with N₂-CO gas mixtures and carbon was measured at 1823 K. The nitride capacity (C _N3-) was calculated to compare the nitrogen contents measured under different nitrogen and oxygen potentials.C _N3- decreased with increasing basicity and by replacing SiO₂ with A1₂O₃. The nitrogen partition ratio between carbon saturated iron and the slag was measured in CO gas at one atmosphere at 1823 K. By comparing the partition ratios with the corresponding nitride capacities measured by the gas-slag experiments, it was concluded that the oxygen partial pressure at the slag-metal interface was controlled by the Fe-FeO reaction. A new definition of nitride capacity was proposed based on the reaction between nitrogen and the network former,i.e., SiO₂ or A1₂O₃. This capacity could consistently explain the experimental results. Empirical equations were derived to estimate the activity coefficients of silicon and aluminum nitrides in the slags. On leave of absence from the Research Institute of Mineral Dressing and Metallurgy, Tohoku University, Sendai, Japan.     

Electrochemical preparation of poly(2,5-dimethoxy-1,4-phenylene)

Summary p-Dimethoxybenzene was electro-oxidatively polymerized to give poly(2,5-dimethoxy-1,4-phenylene) with high yield. 1,4-Structure of polyphenylene was confirmed by ¹³C-NMR and IR spectrum. The polymer was deposited on electrode, and electrolysis solvent affected the polymer yield and morphology of the polymer. In a strongly basic solvent the polymerization was inhibited, which suggests that cation radical of p-dimethoxybenzene is an active species of this polymerization.     

Relation of the infrasound characteristics and the continuous steel bridge vibration modes generated by the vibration of moving heavy trucks

Railway Engineering Science - As heavy trucks pass over highway bridges, bridge vibration occurs and generates infrasound. General trucks in Japan with rear leaf suspension have whole body...     

Distribution equilibria of Pb and Cu between CaO-SiO2-Al2O3 melts and liquid copper

The distribution equilibria of lead and copper between CaO-SiO₂-Al₂O₃ melts and liquid copper were measured at 1623 K under a controlled H₂-CO₂ atmosphere. The distribution ratios were plotted against the oxygen partial pressure, and reasonable oxide forms dissolved in the melts were estimated from the slopes of the plots. The activity coefficients of lead oxide (PbO) and cuprous oxide (CuO_0.5) increased with increasing slag basicity, defined by X _CaO/X _SiO2. The temperature dependence of the activity coefficients of lead oxide and cuprous oxide was also measured.