Clinical evaluation of nitrite test for the detection of bacteriuria

A nitrite test for bacteriuria was compared with routine microscopic examination in 1,318 clinical urine specimens and with bacterial culture in 132. Sensitivity, specificity, positive predictive value and accuracy rate are as follows; for diagnosis of bacteriuria more than 10(4) CFU/ml, 53.4%, 88.6%, 90.4 and 65.2%, respectively; for more than 10(5) CFU/ml, 55.4%, 87.8%, 88.4% and 67.2%, respectively. The positive rate for the nitrite test was 21.4% for bacteriuria of > or = 10(4) CFU/ml in gram positive cocci and 56.9% in gram negative rods. False negative results were obtained from gram positive cocci without nitrate reductive activity or from patients with acute uncomplicated cystitis because of insufficient incubation time in urinary tract. However, this simple test is valuable in the detection of bacteriuria in clinical practice with high specificity.     

An LMI-based approach to critical control system design for rate-limited exogenous inputs

This paper considers a linear matrix inequality approach to the design of critical control systems for rate-limited exogenous inputs. The sufficient condition for ensuring the critical requirement is derived from the exponential convergence condition of the unit step response. By changing the variables, it is transformed into the set of BMI and LMI conditions. The problem amounts to a convex feasibility problem with a line search. The obtained controller has the same order as a plant. To show the validity of the proposed method, a numerical example of multi-conditioned critical control system design is presented.     

Evolvable analog LSIs: Adaptation to process variations via genetic algorithms

We propose a concept of evolvable analog LSIs and apply it to Intermediate Frequency (IF) filters, which are widely used in cellular phones. The developed chip can correct discrepancies in the values of analog circuit components by genetic algorithms (GAs), which have attained (1) a yield rate of 97%, (2) a 60% reduction of the filter area, and (3) a 38% reduction of power dissipation, compared with AKM commercial products. When analog Integrated Circuits (ICs) and Large‐Scale Integrated Circuits (LSIs) are manufactured, the values of the analog circuit components, such as resistors or capacitors, often vary from the precise design specifications. Analog LSIs with such defective components cannot perform at required levels and thus have to be discarded. However, our technique can improve yield rates of analog LSIs and has two additional advantages, namely, smaller circuits and less power dissipation, which can lead to cost reductions and efficient implementation of analog LSIs. This approach could be applied to a wide variety of analog LSIs. © 2001 Scripta Technica, Electr Eng Jpn, 138(3): 63–71, 2002     

Transient characteristics of a tapped‐winding capacitor motor

Tapped‐winding capacitor motors are widely used for fans in air conditioners as speed adjusting motors. In tapped‐winding capacitor motors, the burnout accidents of phase‐shifting capacitors have been seen on occasion. The cause of such accidents is considered to be the transient capacitor current. In this paper, equations for calculating transient characteristics are derived for three types of tapped‐winding capacitor motors. Based on these equations, transient characteristics are clarified in high‐ and low‐speed winding connections. Further, from the design viewpoint, the effects of the turn ratio and capacitance of the capacitor on the transient characteristics are examined and a procedure for choosing the winding ratio and capacitance of the capacitor is suggested. Using this method, the transient current is shown to decrease by about 40%. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(4): 69–77, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10063     

Design and performance of ultra-low-loss single-mode fiber cable in 1.5-µm wavelength region

The structural optimization of single-mode fiber for use in the 1.5-μm wavelength region is made with the aim of minimizing the total transmission-line loss over a repeater section. For example, the optimum ranges of the mode-field radius w0and effective cutoff wavelength λceare determined as 5.5 μmleq w_{0} leq 6.5 mum and 1.35μmleq lambda_{ce} leq 1.53 mum for high bit-rate transmission systems with a repeater spacing of 80 km. Based upon the design, ultra-low-loss single-mode fiber cables are fabricated. The average loss of 108 fibers in the cables is 0.19 dB/km at 1.55 μm. The total loss of a 216-km-long fiber link containing 107 splice points was 46.3 dB. Good loss stability at high temperatures as well as during the cable manufacturing processes, are achieved by the appropriate choices of coating materials and optimized fiber parameters.     

Room-Temperature Preparation of Highly Crystallized Luminescent SrWO4 Film by an Electrochemical Method

Highly crystallized luminescent SrWO₄ film has been prepared on a tungsten substrate in an alkaline solution containing strontlum ions by an electrochemical method using constant direct current of 1 mA/cm² at room temperature (25°C). This film showed only a single blue emission at 461 nm with the excitation of 248 nm at liquid nitrogen temperature (- 196°C), strongly suggesting it consists of well-crystallized defect-free crystals.     

Video-microscopy for analysis of molecular dynamics in cells

Real-time analysis of molecular dynamics in living cells was studied by developed video-microscopes. Two new detective methods were reported, one is for analysis of ciliary movement and the other is the qualitative analysis of exocytosis of insulin-containing granules with a video-enhanced light/fluorescent microscope. For analysis of ciliary movement, glass beads were migrated in the flow. The migration speed parallel to the flow produced by ciliary beating was used as an index of the beating activity. When tracheal epithelium isolated from mouse was incubated with ambroxol, and expectorant known to activate ciliary beat frequency, the floating speeds of glass beads were changed with 1 min of incubation. The results suggest that the present method is useful not only for screening of expectorants but also for the study of molecular mechanisms underlying ciliary beat of tracheal epithelium. Visualization of the moment of the release of contents from insulin-containing granules was achieved using video-enhanced fluorescent microscopy in MIN6 cells of mouse insulinoma cell line. A fluorescent amino acridine dye, quinacrine, was found to be incorporated into low-pH secretory granules, including insulin, in the cells. The granules which incorporated quinacrine emitted a slightly blue-green fluorescence. Upon stimulation with glucose, release of the quinacrine fluorescence from granules were observed. The present method would be useful for quantitative analysis of secretion of insulin from MIN6 cells as well as pancreatic beta-cells.     

Comparative NO x reduction behavior of Pt,Pd, and Rh supported catalysts in simulated exhaust gases as a function of oxygen concentration

Topics in Catalysis - NO x reduction activity on Pt and Pd catalysts had a maximum for S value as stoichiometry number at a fixed temperature, and the S value at the maximum NO x conversion...