Transporters in the neurohypophysial neuroendocrine system, with special reference to vesicular glutamate transporters (BNPI and DNPI): a review.

Recent advances in gene technology have helped to identify novel proteins and allowed study of their distribution and functions in the mammalian brain. One class of these proteins is that of transporters, which exist in plasma and organellar membranes of neurons and other cells to move substances selectively across membranes. These transporters can be categorized further into subclasses by their structural property, substrate selectivity, and site of action. Some of them have been identified in the hypothalamus, which is the only brain site where a neural signal is converted to a humoral one, namely, a hormone for a target organ. This unique neural mechanism has long attracted attention as the neuroendocrine system, part of which has been extensively studied as the hypothalamic-neurohypophysial system involved in secretion of vasopressin and oxytocin. However, transporters in this system have been less well studied. A morphological examination of novel transporters would give us cues to a better understanding of the neuronal organization and function of the system. In this review, we first summarize recent findings on expression of transporter gene and immunoreactivity in the hypothalamus. In the second part, we explain our observations on two vesicular glutamate (inorganic phosphate) transporters (BNPI and DNPI) in the supraoptic and paraventricular nuclei and neurohypophysis. Further study of these and other transporters will provide a basis on which to reevaluate the organization and function of the hypothalamic-neurohypophysial system.     

Gas absorption accompanied by an instantaneous irreversible reaction in laminar falling films of pseudoplastic liquids

Gas absorption accompanied by an instantaneous irreversible chemical reaction into laminar falling films of power-law liquids was studied theoretically. The convective-diffusion equations for a solute gas and a liquid-phase reactant were solved numerically and the numerical solution for the reaction factor was obtained as a function of the Graetz number, the concentration ratio, the diffusivity ratio and the power-law index of the liquid.     

Evolutionary design of dynamic neural networks for evaporator control

This paper presents a novel neural network (NN) to control an ammonia refrigerant evaporator. Inspired by the latest findings on the biological neuron, a dynamic synaptic unit (DSU) is proposed to enhance the information processing capacity of artificial neurons. Treating the dynamic synaptic activity after the nonlinear somatic activity helps to capture the dynamics demarcated by the Gaussian activation pertaining to the input space. This practice leads to a remarkable reduction in curse of dimensionality. The proposed NN architecture has been compared with two other conventional architectures; one with dynamic neural units (DNUs) and the other with nonlinear static functions as perceptrons. The objective is to control evaporator heat flow rate and secondary fluid outlet temperature while keeping the degree of refrigerant superheat in the range 4–7 K at the evaporator outlet by manipulating refrigerant and evaporator secondary fluid flow rates. The drawbacks of conventional approaches to this problem are discussed, and how the novel method can overcome them are presented. An evolutionary approach is adopted to optimize the parameters of the NN controllers. Then evaporator process model is accomplished as a combination of governing equations and a sub NN resulting in a simple and sufficiently accurate model. The effectiveness of the proposed dynamic NN controller for the evaporator system model is validated using experimental data from the ammonia refrigeration plant.     

Ru-catalyzed anode materials for direct hydrocarbon SOFCs

A solid oxide fuel cell using a thin ceria-based electrolyte film with a Ru-catalyzed anode was directly operated on hydrocarbons, including methane, ethane, and propane, at 600 °C. The role of the Ru catalyst in the anode reaction was to promote the reforming reaction of the unreacted hydrocarbons by the produced steam and CO₂, which avoided interference from steam and CO₂ in the gas-phase diffusion of the fuels. The resulting peak power density reached 750 mW cm⁻² with dry methane, which was comparable to the peak power density of 769 mW cm⁻² with wet (2.9 vol.% H₂O) hydrogen. More important was the fact that the cell performance was maintained at a high level regardless of the change in the methane utilization from 12 to 46% but was significantly reduced by increasing the hydrogen utilization from 13 to 42%. While the anodic reaction of hydrogen was controlled by the slow gas diffusion, the anodic reaction of methane was not subject to the onset of such a gas-diffusion process.     

Integrated-optic double-ring resonators with a wide free spectralrange of 100 GHz

Integrated-optic double-ring resonators with a wide free spectral range (FSR) of 100 GHz are fabricated using GeO₂-doped silica waveguides with a high relative refractive index difference (Δ) of 1.5%. The resonators are composed of two ring resonators comprising small ring waveguides with radii of 1.75 and 2.0 mm. The double-ring resonator module exhibited a wide FSR of 98.0 GHz, a finesse of higher than 138, a low crosstalk of less than -11.7 dB, and a low insertion loss of 6.1 dB. The measured FSR of 98.0 GHz is wider than any previously reported ring resonator composed of optical waveguides     

Accelerator Analysis of Tributyltin Adsorbed onto the Surface of a Tributyltin Resistant Marine Pseudoalteromonas sp. Cell

Tributyltin (TBT) released into seawater from ship hulls is a stable marine pollutant and obviously remains in marine environments. We isolated a TBT resistant marine Pseudoalteromonas sp. TBT1 from sediment of a ship’s ballast water. The isolate (10^{9.3 ± 0.2} colony-forming units mL⁻¹) adsorbed TBT in proportion to the concentrations of TBTCl externally added up to 3 mM, where the number of TBT adsorbed by a single cell was estimated to be 10^8.2. The value was reduced to about one-fifth when the lysozyme-treated cells were used. The surface of ethanol treated cells became rough, but the capacity of TBT adsorption was the same as that for native cells. These results indicate that the function of the cell surface, rather than that structure, plays an important role to the adsorption of TBT. The adsorption state of TBT seems to be multi-layer when the number of more than 10^6.8 TBT molecules is adsorbed by a single cell.     

Microstructural observation and reaction mechanism of ZnAI2O4 formation in the presence of various fluorides

The rates of ZnAI₂O₄ formation in the presence of various fluorides were controlled by the nucleation process. The rate constants of the nucleation process for various fluorides were in the order LiF > NaF and MgF₂ > CaF₂ < SrF₂ < BaF₂. This trend corresponds to the order of the promotion of ZnAI₂O₄ formation by these fluorides. In order to interpret the dependence of the kinetic constant of the nucleation of ZnAI₂O₄ from the intermediate phase on the kinds of counter cation of fluorides, it was assumed that the activated state for promotive formation of ZnAI₂O₄ under the presence of fluoride is similar to that of the following reaction: $$ZnO + Al_2 O_3 + 2MF\left( {M'F_2 } \right) = ZnF_2 + M_2 Al_2 O_4 \left( {M'Al_2 O_4 } \right).$$ The order of the rate constant obtained in this study showed agreement with the order of the standard heats of formation for the above reaction. This relation was interpreted by applying the linear free energy relationship (LIFER).     

Sialon formation by Si+ and N2 + ion implantation into sapphire

Single-crystal alumina was implanted firstly with 400 keV Si⁺ and subsequently with N₂ ⁺ ions and then annealed at 1673 K in an No atmosphre. The implanted layers were characterized by means of X-ray diffraction, Rutherford backscattering-channelling of 2 MeV He⁺ ions, and the resonance nuclear reaction¹⁵N(p,)¹²C. The annealing of sapphire implanted at ambient temperature resulted in the formation of-sialon, a solid solution of-silicon nitride and alumina in the subsurface layer, while implantation at 100 K resulted in the formation of aluminium oxynitride in the surface layer. In the latter case, the implanted silicon atoms were believed not to react vxi1h the implanted nitrogen atoms but with the substrate oxygen atoms. These crystalline precipitates were found to have epitaxial relations with the sapphire substrate.     

Electrochemical removal of both NO and CH4 under lean-burn conditions

An electrochemical cell, Pd|YSZ|Pd, was constructed in order to remove both NO and CH₄ in the presence of excess oxygen. When direct current was supplied to the cell with a flow of a mixture of NO, CH₄, O₂, H₂O and CO₂ at 700° C, NO was reduced to nitrogen at the cathode, and CH₄ was oxidized to CO _x at both the anode and cathode. At the cathode, the reduction of NO and the oxidation of CH₄ proceeded with the removal of chemisorbed oxygen species from the Pd surface, and at the anode, the oxidation of CH₄ was enhanced by forming an active oxygen atom.