In situ observation of freeze-fractured and deep-etched red blood cells with a high-vacuum low-temperature atomic force microscope

A high-vacuum low-temperature atomic force microscope (AFM) for the direct observation of freeze-fracture samples has been developed. This AFM has a freeze-fracture mechanism inside the vacuum chamber. With this AFM it is possible to observe the fractured surface directly without both fabricating a replica and exposure to the ambient atmosphere. Both sandwich and knife fracture methods have been achieved to obtain freeze-fracture surfaces and after deep etching. A fine structure of the fractured red blood cell membrane has been observed using both methods. These are relatively quick and easy methods for the observation of freeze-fracture surfaces without introducing replica artifacts.     

Removal of radioactive methyl iodide by silver impregnated alumina and zeolite

The removal efficiency of methyl iodide for silver impregnated alumina and zeolite has been experimentally evaluated as functions of the relative humidity in the atmosphere and the amount of impregnated silver. At high relative humidities silver alumina performs with a larger removal efficiency using a smaller amount of impregnated silver than does silver zeolite. This difference is explained by effective reacting surface. The pore size dependency is correlated with the pore diffusion rate as the determining adsorption mechanism.     

250 Mbyte/s synchronous DRAM using a 3-stage-pipelined architecture

A 3.3-V 512-k×18-b×2-bank synchronous DRAM (SDRAM) has been developed using a novel 3-stage-pipelined architecture. The address-access path which is usually designed by analog means is digitized, separated into three stages by latch circuits at the column switch and data-out buffer. Since this architecture requires no additional read/write bus and data amp, it minimizes an increase in die size. Using the standardized GTL interface, a 250-Mbyte/s synchronous DRAM with die size of 113.7-mm², which is the same die size as the conventional DRAM, has been achieved with 0.50-μm CMOS process technology     

INITIATION AND GROWTH OF SMALL CRACKS IN DIRECTIONALLY SOLIDIFIED MAR-M247 UNDER CREEP-FATIGUE. PART I: EFFECT OF MICROSTRUCTURE

This paper deals with the initiation and growth of small cracks in a directionally solidified superalloy, Mar-M247.     

Harmonic analysis of a single-phase rectifier with a DC filter capacitor

A single-phase diode bridge rectifier with a filter capacitor on the dc side is often employed to convert ac input into a dc voltage. The input current of the rectifier contains harmonic currents which cause undesirable power line effects. Recently, a method using the time domain analysis has been proposed to calculate the harmonic currents of rectifier considering noninfinite capacitance, i.e., non-zero dc side impedance. This method is very accurate, but it requires a long computing time and a complicated algorithm. This paper proposes a new method that makes it possible to easily calculate the harmonic currents taking into account the effects of the ac and dc side impedances of rectifier. The proposed method, which is based on the frequency domain method, can be executed only with the algebraic computation, and its accuracy is quite high. The validity of the proposed method is also demonstrated by comparison with the results of time simulation.     

Endothelial cells actively synthesize and secrete adrenomedullin

This study demonstrates active production of adrenomedullin (AM) in cultured vascular endothelial cells (ECs). To identify the origin of plasma AM and its functional relationship to vascular smooth muscle cells (VSMCs), we checked production of AM in a series of tissues and cell lines and found immunoreactive (ir-) AM in culture media of rat, porcine, human and bovine ECs. Ir-AM was accumulated linearly for up to 48 hours in the culture medium of rat ECs, and the secretion rate of AM was almost comparable to that of endothelin-1. By gel filtration and reverse phase high performance liquid chromatography, ir-AM in the culture medium was shown to have chromatographic behavior indistinguishable from that of synthetic rat AM. By RNA blot analysis of rat tissue, the most highly positive band was detected in cultured ECs, at an intensity 20 to 40 fold higher than that in adrenal gland. Based on these data as well as the presence of AM specific receptor on VSMCs, AM secreted from ECs is deduced to act directly on VSMCs, regulating vascular tone.