Absence of nonpercutaneous transmission of hepatitis C virus in a colony of chimpanzees

Transmission of hepatitis C virus (HCV) was studied in a colony of 85 chimpanzees using assays for anti-HCV and HCV-RNA. Thirteen of the 85 sera were positive for anti-HCV, and 12 of the 13 were also positive for HCV-RNA. All of the anti-HCV positive sera except one were obtained from chimpanzees which had been inoculated with non-A, non-B hepatitis virus. On the other hand, only one of 63 sera of chimpanzees without history of experimental infection of the virus was positive for anti-HCV. Transmission to this chimpanzee was thought to be a needle contaminated with HCV. All 39 samples of chimpanzees born in the center were negative for both anti-HCV and HCV-RNA. Sixteen of their mothers had undergone experimental infection, and 6 of them were positive for both anti-HCV and HCV-RNA. These results suggest that nonpercutaneous transmission, including sexual and mother-to-infant transmissions, is not an important mode of transmission. If these findings apply to humans, definition of inapparent sources of the infection is needed.     

Accelerated idioventricular rhythm in three newborn infants with congenital heart disease

Accelerated idioventricular rhythm was observed in three newborn infants with congenital heart disease. This ventricular arrhythmia in all of our patients did not alter the clinical features of the congenital heart disease, and it disappeared at the ages of 84 days, 40 days, and 45 days, respectively. This arrhythmia is generally considered to be benign, which also appears to be the case with the newborn infant with congenital heart disease.     

Treatment of intrahepatic gallstone

The postoperative outcomes in patients with hepatolithiasis are greatly affected by the presence of residual stones. One hundred and seventeen patients with hepatolithiasis treated in our clinic were analysed. The indication of hepatectomy for hepatolithiasis was determined by the degree of stricture of intrahepatic bile duct. The rate of residual stones was reduced from 54.5% to 14.5% by the introduction of choledochoscopical lithotomy. Thus, pre- and postoperative choledochoscopical examination and lithotomy are shown to play an important role in treatment of the patients with hepatolithiasis.     

Signal-integrity improvement method and its robustness evaluation for VLSI and VLSI-packaging

Nowadays, a GHz frequency signal needs to be propagated on a printed circuit board (PCB) with low distortions. In addition, a higher-frequency signal of 10 GHz or more will also need to be propagated with low distortion in very-large-scale integration (VLSI) in the future. However, signal propagation with low distortion is getting more and more difficult as the frequency increases. In order to solve this problem and to ensure signal integrity, we have proposed a novel transmission line called a “segmental transmission line” (STL). In the STL, a transmission line is divided into multiple segments of individual characteristic impedance. The multiple segments are designed to fix the waveform distortion on the transmission line by solving a combinatorial explosion problem using a genetic algorithm. In a previous article, we have shown the effectiveness of an STL designed for a GHz clock signal in computer simulations. We have also fabricated two scaled-up STL prototypes for a clock signal using real printed circuit boards (PCBs). In this article, we input a random signal by changing its frequency to the scaled-up STL prototype designed for a 150-MHz clock signal. We show that the STL has high robustness to the random signals and the frequency fluctuations, which indicates the generality of the STL technique.     

Ultra-sensitive high-speed density measurement of the “piston effect” in a critical fluid

In order to conduct a detailed investigation of the piston effect, the peculiar heat transportation phenomenon in critical fluids, an ultra-sensitive high-speed density measurement system was developed using a very thin heater, a sensitive interferometer and a large-capacity high-speed data acquisition system. As the first step of the investigation, an experiment was conducted to measure the velocity of sound in CO2 near its critical point. Short heat pulses suppressing the disturbance of natural convection were applied to a small cell filled with almost-critical CO2 fluid and were detected by the measurement system. Because the pulses propagated through the cell at the velocity of sound and were reflected several times between the cell walls, the velocity could be precisely determined by measuring the time intervals between successive reflections. The resulting velocity profile versus temperature showed good agreement with theoretical prediction and numerical simulations. This result validated the density measurement system, and it is considered that the measurement system will be a very effective tool for further studies on critical phenomena with the aid of numerical simulation.     

Memory array architecture and decoding scheme for 3 V only sectorerasable DINOR flash memory

A memory array architecture and row decoding scheme for a 3 V only DINOR (divided bit line NOR) flash memory has been designed. A new sector organization realizes one word line driver per two word lines, which is conformable to tight word line pitch. A hierarchical negative voltage switching row decoder and a compact source line driver have been developed for 1 K byte sector erase without increasing the chip size. A bit-by-bit programming control and a low threshold voltage detection circuit provide a high speed random access time at low V_cc and a narrow program threshold voltage distribution. A 4 Mb DINOR flash memory test device was fabricated from 0.5 μm, double-layer metal, triple polysilicon, triple well CMOS process. The cell measures 1.8×1.6 μm² and the chip measures 5.8×5.0 mm ². The divided bit line structure realizes a small NOR type memory cell     

A case of polymyalgia rheumatica with swelling and pitting edema of the distal lower extremities

We report a case of an 82-year-old woman with polymyalgia rheumatica (PMR) associated with swelling and pitting edema of the lower extremities. The patient had been previously admitted because of PMR in 1990, but there was no history of swollen extremities. In July 1996, at another hospital, she was again diagnosed as having PMR on the basis of pain in the neck, shoulders and lower back. Administration of prednisolone was followed by improvement of the symptoms. Four months later, similar pain recurred and swelling of the lower extremities was noted. On admission, the erythrocyte sedimentation rate was 86 mm/h, and C-reactive protein was 15.5 mg/dl. Reviewing the previous treatment, it was ascertained that her clinical deterioration was due to premature reduction of the steroid dosage. The cause of the swelling of the lower extremities was unlikely to be heart, liver, kidney or endocrine disease. Prednisolone was increased from 2.5 mg to 10 mg daily with marked improvement in all the symptoms including the swelling and pitting edema. In 1996, a study reported distal extremity swelling with pitting edema as a manifestation of PMR, which mostly developed concurrently with proximal symptoms or during relapses of PMR. The swelling responded poorly to non-steroidal antiinflammatory drugs but promptly to corticosteroids. The distal swelling was reported to be tenosynovitis and synovitis of the surrounding structures. The present case appears similar to that report. More studies of PMR need to be done.     

An evolutionary design methodology of printed circuit boards for high-speed VLSIs

As operation frequencies of the printed circuit boards (PCBs) increase in keeping with VLSI frequencies in the GHz domain, two independent serious problems occur in the PCB design. One is waveform distortion problem, or signal integrity (SI) degradation problem, in PCB traces. And the other is power-supply drop problem, or power integrity (PI) degradation problem, in PCB power planes. Those problems are barely able to be overcome on case-by-case empirical designs conventionally. In this paper we newly propose a design approach for each problem, both of which are based on the genetic algorithm. And we obtained improvement ratios of more than double compared with the both conventional designs for SI and PI degradations, respectively.     

Stereoscopic 3‐D display with optical correction for the reduction of the discrepancy between accommodation and convergence

Abstract— This paper describes a method for reducing the discrepancy between accommodation and convergence when viewing stereoscopic 3‐D images. The method uses a newly developed stereoscopic 3‐D display system with a telecentric optical system and a mobile LCD. The examination of a mono‐focal lens showed that a correction lens having the appropriate refractive power and conditions for presenting stereoscopic 3‐D images clearly reduces the discrepancy between accommodation and convergence. The authors also developed a stereoscopic 3‐D display that uses dynamic optical correction to reduce the discrepancy between accommodation and convergence. The display equalizes the theoretical points of accommodation and convergence. The purpose of the development was to expand the regeneration range of a stereoscopic 3‐D image having the appropriate accommodation. An evaluation of the developed display showed that it resolves the discrepancy between convergence and accommodation.     

Microstructure development in SnO2 with and without additives

The microstructure development in pure and ZnO-, Nb₂O₅- or (ZnO + Nb₂O₅)-containing SnO₂ has been studied. Sintering of pure SnO₂ proceeds by an evaporation-condensation mechanism and grain and pore sizes increase without densification. The pores are open with no closed pores developed. Grain and pore structures become homogeneous with sintering time. Sintered pure SnO₂ is porous and has large grains. Nb₂O₅ suppresses particle coarsening and pore growth but does not promote densification, leading to porous sintered bodies with small grains. ZnO and (ZnO + Nb₂O₅) promote densification but do not suppress particle and grain coarsening. The sintered body is composed of large grains with pores located on grain boundaries.