Quality control material for plasma fibrinogen test produced from purified human fibrinogen

Plasma fibrinogen measurement is a routine laboratory procedure commonly performed on automated coagulation analysers. Its determination is quantitative, not quantitative. Yet, a lack of precision has been an issue for fibrinogen measurement. A control material derived from plasma comprises many proteins, inhibitors and fatty acids, any or all of which can interfere in the fibrinogen assay. This study has attempted to develop a quality control material using purified human fibrinogen and has compared measurement precision between both purified and plasma materials. Purified fibrinogen was prepared using Cohn fraction 1 and glycine precipitation. Purified fibrinogen clottability was greater than 95%, with no main plasma proteins, lipids or fibrinogen degradation products observed. Two purified control materials were lyophilized at normal (2.30 g l(m1)) and abnormal (1.20 g l(m1)) levels of fibrinogen concentration. Precision was evaluated using a liquid-type reagent, Thrombocheck Fib(L), on automated coagulation analysers. Coefficient of variation for within-run, intraday and between-day precision of the purified materials was 0.7-3.5%. In comparison, the coefficient of variation for plasma materials ranged from 1.2 to 5.3%. These results suggest that materials prepared from purified fibrinogen can be useful to laboratory quality control by improving overall precision of fibrinogen measurement and are applicable to automated coagulation analysers.     

Synthesis of poly {4-[bis(trimethylstannyl)methyl]styrene} and its properties for electron-beam resist

Summary To create high performance resist materials, synthesis of novel organostannun-containing polymer was investigated. 4-[Bis(trimethylstannyl)methyl]styrene (BSnMS) was synthesized by a reaction between trimethylstannyl chloride and 4-vinylbenzyllithium that was prepared through a metalation reaction of 4-methylstyrene by lithium diisopropylamide. Radical polymerization of BSnMS proceeded smoothly to give a polymer. Glass transition temperature of poly(BSnMS) (Tg=140°C) was fairly high among polystyrene homologues. Poly(BSnMS) thus obtained showed naga-working properties toward EB exposure. Sensitivity of the poly(BSnMS) was 9.0∼9.6 mC cm^-2, keeping high γ-value (3.2∼4.9).     

0.15-μm RF CMOS technology compatible with logic CMOS forlow-voltage operation

Radio Frequency (RF) CMOS is expected to replace bipolar and GaAs MESFETs in RF front-end ICs for mobile telecommunications devices in the near future. In order for the RF CMOS to be popularly used in this application, compatibility of its process for high-speed logic CMOS and low supply voltage operation are important for low fabrication cost and low power consumption. In this paper, a 0.15-μm RF CMOS technology compatible with logic CMOS for low-voltage operation is described. Because the fabrication process is the same as the high-speed logic CMOS, manufacturability of this technology is excellent. Some of the passive elements can be integrated without changing the process and others can be integrated with the addition of a few optional processes. Mixed RF and logic CMOS devices in a one-chip LSI can be realized with relatively low cost. Excellent high-frequency characteristics of small geometry silicon MOSFETs with low-power supply voltage are demonstrated. Cutoff frequency of 42 GHz of n-MOSFETs, which is almost the same level at that of general high-performance silicon bipolar transistors, was obtained. N-MOSFET's maintained enough high cutoff frequency of 32 GHz even at extremely low supply voltage of 0.5 V. Moreover, it was confirmed that degradation of minimum noise figure for deep submicron MOSFETs with 0.5 V operation is sufficiently small compared with 2.0 V operation. These excellent high-frequency characteristics of small geometry silicon MOSFETs under low-voltage operation are suitable for mobile telecommunications applications     

Synthesis and polymerization of new vinyl derivatives of thymine

N-acryloyl and N-methacryloyl derivatives of thymine were prepared by one-step reaction of silylated thymine with acryloyl chloride and methacryloyl chloride, respectively, in good yields. These vinyl monomers containing thymines were polymerized and copolymerized with water soluble vinyl monomers such as acrylamide and vinylpyrrolidone by free-radical polymerization. Complex formation between copolymers and RNA in aqueous solution was studied by means of UV spectroscopy.     

Correlation of fasting blood glucose and haemoglobin A1c measured with an automated analyser

A subtype of glycohaemoglobin, haemoglobin (Hb) A_1c, in specimens of whole blood was assayed on a new automated analyser that makes use of high-pressure liquid chromatography. The analyser provided precise and reproducible values. The mean of the HbA_1c values was lower than that with an older instrument. The mean tended to increase with the age of the subjects, who were undergoing routine health examinations. No sex difference was found. When measurement was made 1 h after the subjects drank 50g of glucose, the value of HbA_1c was unaffected. Correlation was strong between the HbA_1c value and the fasting blood glucose value, which suggested that fasting blood glucose could be estimated from the HbA_1c value.     

Characteristics of an induction motor with reduced turns of terminal coils

The use of PWM inverters with high switching characteristics for the adjustable speed drive system causes an overvoltage with steep‐fronted waveform on the motor terminals. As this steep‐fronted transient voltage in inverter drive loads heavily on the terminal coils of motor winding, the insulation failure in the motor winding occurs mostly on the terminal coils. Therefore, it is reasonable to reduce the turns of terminal coils only and to increase the dielectric strength of interturn insulation. This paper presents a comparison of measured characteristics of normal induction motors and induction motors with reduced turns of terminal coils and also a comparison of the results measured and calculated by equivalent circuit. The appropriate rate of reduced turns of terminal coils is about 20%. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(3): 49–56, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10093