Showing papers by "Hiroshi Yoshida published in 1997"

Receiver having DC offset decreasing function and communication system using the same

Abstract: A receiver having a function of a direct current offset, and including a receiving section for receiving a radio frequency signal, an analog signal processing section for amplifying, band-converting and frequency-converting an analog signal inputted from the receiving section, and an AD converting section for converting an output of the analog signal processing section from an analog signal to a digital signal. Also included is a digital signal processing section for processing the digital signal converted by the DC converting section. The receiver further includes an offset detecting element, provided in the digital signal processing section, for detecting a direct current offset signal produced in the receiving section or a frequency converting section, an offset holding element, provided in the digital signal processing section, for holding the direct current offset signal detected by the offset detecting element, a DA converting section for converting the direct current offset signal detected by the digital signal processing section into an analog signal, and a first offset correcting element, provided in the analog signal processing section, for correcting the analog signal on the basis of the direct current offset signal converted by the DA converting section into the analog signal.

NF00659A1, A2, A3, B1 and B2, Novel Antitumor Antibiotics Produced by Aspergillus sp. NF 00659

Abstract: Five novel cytotoxic antibiotics, NF00659A1 (1), A2(2), A3(3), B1(4) and B2(5) were discovered. They were isolated from a culture mycelium of Aspergillus sp. These compounds were proved to have 4, 5-seco-tricyclic diterpene α-pyrone structure by spectroscopic analyses. They showed potent antitumor activities against human ovarian carcinoma A2780 and human colorectal adenocarcinoma SW480 cells, but did not show any antimicrobial activities at 1, 000μg/ml against Gram-positive and Gram-negative bacteria, yeasts and fungi.

Poly(phenylhydrosilane): Base-developable polysilane resist

Abstract: Poly(phenylhydrosilane) becomes soluble in a 2.38% tetramethylammoniumhydroxide aqueous solution after exposure to UV light. This is the first report that the polysilanes not bearing acidic groups can be developed with dilute basic aqueous solutions. Addition of 3,3′,4,4′-tetra(t-butylperoxycarbonyl)benzophenone increases the resist sensitivity. The reaction mechanism is as follows: PS1 photodecomposes to form silyl compounds having SiOH groups, which become soluble in an aqueous base solution, because these silane compounds bearing SiOHs are acidic. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2355–2364, 1997

Survey of sensitivities of clinical isolates to antibacterial agents (annual report)

Abstract: Research groups were formed in 20 institutions nationwide to investigate carbapenem resistance of clinical isolates. Activities of various antibacterial agents, principally carbapenems, were tested against clinical isolates collected from these institutions. The broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) of 17 antibacterial agents for 1,326 strains of 11 bacterial species isolated at the institutions between October and December 1994. The results are as follows: 1. Carbapenems exhibited strong antibacterial activities against MSSA and Streptococcus pneumoniae. Their activities against Enterococcus faecalis were comparable to that of ABPC. Carbapenems showed low activities against MRSA. 2. OFLX exhibited the greatest antibacterial activity against Haemophilus influenzae, followed by MEPM. Antibacterial activities of the other carbapenems were comparable to those of FMOX, CTM, and ABPC. 3. The carbapenems showed high activities against Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, and Bacteroides fragilis group. Their activities were greater than those exhibited by other beta-lactam antibacterial agents. The carbapenems also exhibited stronger antibacterial activities against Serratia marcescens than the other beta-lactam antibacterial agents, but some resistant strains were detected. 4. The antibacterial activities of carbapenems against Pseudomonas aeruginosa were comparable to those of CAZ, AZT, AMK.

Liquid crystal element evaluating method and evaluating device

Abstract: PROBLEM TO BE SOLVED: To easily carry out detection, identification, and quantitative determination of an electric field responsive impurity in a liquid crystal element with high sensitivity by analyzing slope of an electric field response curve when pulse electric fields, which are different from each other in polarity, are impressed to the liquid crystal element. SOLUTION: A pulse signal generated in a pulse generator 1 is impressed to a liquid crystal cell 10. On the other hand, infrared light from an infrared light source 2 is dispersed in an infrared spectroscope 3, and an infrared light of a specific wavelength area is taken out so as to irradiate the cell 10 via a polarizer 4, and then, the infrared light transmitted through the cell 10 is detected by means of a MCT detector 5 so as to be transduced into an electric signal. This electric signal is amplified by means of a preamplifier 6 and a main amplifier 7 so as to be inputted to a digital sampling oscilloscope 8, and then, integration is carried out after time resolution. The whole of an estimating device is controlled by means of a computer 9. Light in excessive wavelength areas other than a measured objective wavelength area can be cut out by means of the spectroscope 3. Therefore, temperature increase in the cell 10 can be suppressed, and a condition adequate for measurement of an electric field response curve can be maintained.