Clonidine reduces dopamine and increases GABA in the nucleus accumbens: an in vivo microdialysis study

The spectrum of infectious disease (ID) emergencies in hospitalized patients was assessed in a prospective study of 3,626 inpatient ID consultations in a 1,350-bed teaching hospital. ID emergencies, defined by a need or anticipated need for advanced life support or by irreversible organ damage leading to permanent functional loss, were encountered in 175 patients. Infections of the central nervous system (26.3%), cardiovascular system (14.9%), alimentary system (13.1%), and lower respiratory tract (7.4%) and adverse reactions to antimicrobial agents (7.4%) were most common. In 18.9% of the cases, the referring clinicians were unaware of the emergency at the time of referral. Drug reactions (46.1%), severe alimentary and peritoneal infections (32.0%), upper respiratory tract infections (28.6%), and skin and soft-tissue infections (27.3%) were most frequently missed. The emergency ID conditions were not recognized because they had an atypical presentation (51.5%), were not commonly seen in the referring specialty (24.2%), were due to rare organisms (15.2%), or had unusual anatomical sites of involvement (9.1%). A close liaison between clinicians and the ID team is crucial for recognition of ID emergencies at their early stages so that appropriate investigations and management can be instituted expediently, before the occurrence of irreversible damage.     

Photocatalytic water splitting into H2 and O2 over various tantalate photocatalysts

Photocatalytic water splitting into H₂ and O₂ over various tantalates was reviewed and factors affecting photocatalytic activities of tantalates were discussed from a viewpoint of the crystal structure and the energy structure. Many tantalates, K₃Ta₃Si₂O₁₃, alkali and alkaline earth tantalates, were highly active photocatalysts for water splitting. The high activities were mainly due to the high conduction band level consisting of Ta5d orbitals. NiO-loaded NaTaO₃ with the distorted perovskite structure showed the highest activity among tantalates. Moreover, the activity of the NiO/NaTaO₃ photocatalyst was remarkably improved by doping of lanthanoids. The apparent quantum yield of NiO/NaTaO₃ doped with lanthanum was ca. 50% at 270 nm.     

Pulsed laser focusing for triggering arc discharge in an arc welding system

In tungsten inert gas (TIG) arc welding systems, arc plasma is generated between the cathode (tungsten rod) and anode (workpiece).¹ Availability of a dependable technique for triggering arc discharge is indispensable for production processes using arc welding. Typical conventional triggering techniques include the high-frequency, high-voltage and touch-start methods. The high-frequency and high-voltage methods involve arc discharge being triggered through ionization of the gas present between the electrodes by means of a conventional high-frequency generator or high-voltage DC generator.² The high-frequency method, however, may possibly disrupt operation of peripheral computer systems, whereas the high-voltage method involves suitable electric circuits being arranged inside the power source to prevent high voltage-related accidents.^{2, 3} After the rod is lowered to make contact with the workpiece in the touch-start method, it is quickly withdrawn to trigger the arc. This method obviates the need for any power source other than the arc welding power source. An important advantage of the touch-start method therefore is its simplicity. When the rod is withdrawn, however, part of it (tungsten) may sustain melt-through to the workpiece in a way that adversely affects weld quality. This is a disadvantage of the touch-start method.₃     

Host genes affecting survival period of chemically induced bladder cancer in mice

Treatment of C57BL/6 J (B6) and NON male mice with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) resulted in a high incidence of bladder cancer. The mean survival period, however, differed significantly by strain: 481+/-219 days in B6 (n = 31) and 203+/-119 days in NON (n = 30) (P < 0.0001). Major causes of death were renal failure due to obstruction of the urinary tract, or local invasion of tumors. The fact that the BBN-treated NON x B6 reciprocal F1 mice had survival periods as short as those of the parental NON mice suggests a genetically dominant susceptibility in NON or recessive resistance in B6. A linkage analysis of 248 back-cross mice to B6 suggested at least two quantitative trait loci determining the length of the survival period: one was mapped close to D2Mit260 (logarithm of odds, LOD, score 2.21), a microsatellite marker locus 83 cM from the centromere on chromosome 2, and another was close to D6Mit159, 7 cM from the centromere on chromosome 6 (LOD score 2.51).     

100 Å-thick tunnel junction by double impurity doping liquid phase epitaxy for V-band TUNNETT oscillation

The tunnel injection transit time (TUNNETT) diodes with p⁺p⁺n⁺n⁻n⁺ structure were fabricated by liquid phase epitaxy (LPE). About 100 Å tunnel junction (p⁺n⁺) was successfully prepared by the double impurity diffusion of Ge and S during LPE growth. Continuous wave (CW) oscillation was realized at 51.520 GHz in the V-band cavity with the phase noise of −60 dBc/Hz at 1 kHz bandwidth.     

Novel design scheme for high-speed MQW lasers with enhanceddifferential gain and reduced carrier transport effect

We present a theoretical analysis exploring the optimum design of high-speed multiple-quantum-well (MQW) lasers for 1.55-μm operation. Various combinations of well and barrier materials are examined for lattice-matched, strained-layered (SL), and strain-compensated (SC) MQW lasers with InGaAsP and InGaAlAs barriers. The gain characteristics are investigated for these MQW lasers with various barrier bandgap wavelengths and are used to evaluate the modulation characteristics based on the carrier dynamics model which includes a set of Poisson, continuity, and rate equations. The importance of band engineering aimed at simultaneously reducing the carrier transport effect and enhancing the differential gain is described. It is shown that SC-MQW lasers with InGaAlAs barriers have an advantage in reducing the density of states in the valence band by reducing the overlap integral between the heavy- and light-hole wave functions, which effect has previously been discarded as a minor correction in designing conventional InGaAsP-based MQW lasers. Furthermore, the hole transport rate across the barriers can be drastically reduced in SC-MQW lasers due to the reduced effective barrier height for the holes. Based on this novel design scheme, a 3-dB bandwidth approaching 70 GHz is expected for 20-well SC-MQW lasers with InGaAlAs barriers as a result of both the large differential gain and reduced transport effect     

Distributed memory implementation of KLIC

This paper describes external reference management and distributed unification in a distributed implementation of a concurrent logic programming language KL1. This implementation is based on the KLIC system. KLIC has a feature calledgeneric objects that enable easy modification and extension of the system without changes in the core implementation. This distributed implementation is built upon the same core and external references are represented using generic objects. Unification operations are defined as methods of generic objects. Since creation of interprocessor reference loops cannot be avoided, we studied a new unification scheme that can cope with interprocessor reference loops. We built several experimental distributed systems that all demonstrate reasonable efficiency.     

A pulsewidth-modulated inverter with parallel connected transistorsusing current-sharing reactors

A technique for parallel connection of transistors by using current-sharing reactors for the pulse-width-modulated (PWM) transistor inverter is reported. The technique not only increases current capacity, but also decreases the output harmonic contents. The output voltage waveforms of the proposed inverter have certain voltage levels during their half cycles, and thus it is anticipated that it will be difficult to analyze the output harmonics. For such waveforms, a frequency analysis approach is described, and its results are verified by experiments     

Design and analysis of a mass spectrometer with superimposed magnetic and rotating electric fields

We planned to develop a small and inexpensive measurement device for determination of molecular concentration. The analysis process operates by superimposing a rotating electric field on a magnetic field. When the strength and frequency of the rotating electric field and the mass and speed of the ion are predetermined, the circular radius of the ion's trajectory is fixed. We designed a computer program to simulate ion movement in the electric field and magnetic field. It is possible to calculate the circular movement of the ion in the rotating electric field, and then calculate the circular movement in the superimposed state of the rotating electric field and magnetic field. The magnitude of the mass spectrometer conventionally determines resolution ability. Our definition of resolution is the fraction equal to the distance of separation divided by the distance of the attainment point. The resolution increases gradually at first, and then rises suddenly and dramatically to over 20 times the resolution of that of a spectrometer which does not use a superimposed field. We believe that the theory of ion movement in the rotating electric field and magnetic field could lead to the development of a small and inexpensive analysis machine. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 143(1): 15–26, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10113     

Degradation of polymers by high-speed stirring

Benzene solutions containing either poly(ethylene oxide) or poly(methyl methacrylate) or both of varying concentrations were prepared, stirred at a speed of 30,000 rpm, and the effects of concentrations of the same species or different species of polymers on the degradation of the polymers were investigated. Within experimental error little difference was observed in the [η] curves measured for each degraded polymer in spite of change in concentration. It is clear that the degradation of polymer with high-speed stirring in the concentration range 1–4% w/v is not caused by the interaction of polymer chains.