Synthesis of Heterocycle-Containing [60]Fullerene Derivatives. II.1 Recent Progress in [4 2]- and [3 2]-Cycloaddition Routes

Recent progress of synthesis of C₆₀ derivatives functionalized with hetero-cycles is reviewed, focusing attention on [4+2]- and [3+2] cycloaddition methodologies and oxidative heterocyclization.     

Basic fibroblast growth factor as one of the essential factors regulating lens transdifferentiation of pigmented epithelial cells

In vitro transdifferentiation of retinal pigmented epithelial cells of the chick embryo into lens cells can be markedly enhanced by culture in the presence of testicular hyaluronidase and phenylthiourea. Since the commercial preparations of hyaluronidase that had previously been used were very crude, a search for the actual effective molecule(s) enhancing lens transdifferentiation was conducted. First, we purified the enzyme and tested the effect of the purified hyaluronidase. Highly purified hyaluronidase itself did not enhance lens transdifferentiation. The crude hyaluronidase was then separated according to affinity with heparin, considering the possibility that the fibroblast growth factor (FGF) is contained in the crude hyaluronidase. Transdifferentiation-enhancing activity was detected in the fraction which was bound to heparin and eluted with 2 M NaCl, where no hyaluronate-degrading activity existed. Analysis of the fraction by SDS-PAGE revealed the existence of an 18 kDa protein whose NH2-terminal sequence was identical to that of basic FGF. The basic FGF derived from bovine brain also enhanced lens transdifferentiation of pigmented epithelial cells. These findings suggest that basic FGF must play a major role in enhancing transdifferentiation of pigmented epithelial cells to lens cells.     

A new method for power generation planning and problems of uncertainty

This paper presents a new method for power system planning which considers uncertainties of various system parameters as a part of the criterion function. The criterion function involves both the expected values of total system costs and the cost variances of different power plants. Previously, the authors proposed that these cost variances be evaluated from the existing power system plans in the form of the solutions to the inverse optimization problem, and then applied this procedure to the planning of power systems in Japan. However, because of the correlation between fuel and facility costs, the cost variances could not be determined as specific values. Here, to overcome this difficulty, the authors now introduce hydropower plants into the model as the so-called nonrisky elements and focus on the expenditure shares rather than the plant capacity shares. As a result, more reasonable results are obtained. This improved methodology is applied and the derived cost variances are shown. Further, using the resultant cost variances, the authors make Pareto-optimal power generation plans and demonstrate also the robustness of the method to price fluctuations.     

An effect of microstructure on the interface resistance between a perovskite-type oxide electrode and yttria-stabilized zirconia

The electrode characteristics of perovskite-type oxides, La_0.6Sr_0.4CoO₃ and La_0.6Sr_0.4MnO₃, on ceria-based oxide and stabilized zirconia were analysed by the a.c. impedance method. The ionic conductivities of the electrolyte and electrode conductivities from the a.c. impedance analysis agreed with those obtained from the current interruption and d.c. four-probe methods. Two semicircles from the charge transfer and diffusion processes appeared as the electrode resistance. The relative contribution of these two processes to the overall electrode resistance strongly depended on the microstructure of the electrode. The electrode microstructure could be controlled by the dispersion medium used for the electrode slurry. The La_0.6Sr_0.4MnO₃ electrode coated with n-butyl acetate slurry exhibited the smallest electrode resistance.     

Psychological dimensions of risk assessment: Risk perception and risk communication

People fear risks and try to avoid them. With a basic innate drive of sensing risks and protecting safety, humans can survive both natural and man-made catastrophes. Modern science and technology considerably serve for predicting risks and lend themselves to increasing protection for humans. In recent years, however, perception and communication gaps seem to be sharpening between scientists and lay public as to what is safe and how safe is safe enough. The present paper is an attempt to illustrate the causes of such perception and communication gaps and present some empirical evidence to understand the psychological foundation of fears in the lay public.     

Nicotinamide Phosphoribosyltransferase as a Key Molecule of the Aging/Senescence Process

Aging is a phenomenon underlined by complex molecular and biochemical changes that occur over time. One of the metabolites that is gaining strong research interest is nicotinamide adenine dinucleotide, NAD⁺, whose cellular level has been shown to decrease with age in various tissues of model animals and humans. Administration of NAD⁺ precursors, nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR), to supplement NAD⁺ production through the NAD⁺ salvage pathway has been demonstrated to slow down aging processes in mice. Therefore, NAD⁺ is a critical metabolite now understood to mitigate age-related tissue function decline and prevent age-related diseases in aging animals. In human clinical trials, administration of NAD⁺ precursors to the elderly is being used to address systemic age-associated physiological decline. Among NAD⁺ biosynthesis pathways in mammals, the NAD⁺ salvage pathway is the dominant pathway in most of tissues, and NAMPT is the rate limiting enzyme of this pathway. However, only a few activators of NAMPT, which are supposed to increase NAD⁺, have been developed so far. In this review, we will focus on the importance of NAD⁺ and the possible application of an activator of NAMPT to promote successive aging.     

Development of a high‐resolution RGBW flexible display using a white organic light‐emitting diode with microcavity structure and that of a side‐roll touch panel

In this study, white organic electroluminescent devices with microcavity structures were developed. A flexible high‐resolution active‐matrix organic light‐emitting diode display with low power consumption using red, green, blue, and white sub‐pixels formed by a color‐filter method was fabricated. In addition, a side‐roll touch display was developed in combination with a capacitive flexible touch screen.