Syntheses of functional condensation polymers. II. A polyamide having epoxy groups and its ring-opening derivatives

Polyamides having epoxy groups and their ring-opening derivatives were prepared and characterized, and some of their properties were investigated. Reaction conditions for the low-temperature polycondensation of cis-2,3-epoxysuccinyl chloride (ESC) with aromatic diamines and the interfacial copolycondensation of ESC and adipyl chloride (AC) with aromatic diamines were established to obtain a high molecular weight polyamide having epoxy groups. In addition, the ring-opening reactions of the epoxy groups in the polyamides were carried out with various amines in order to obtain polyamides having hydrophilic pendent groups such as amino and hydroxyl. It was found that the polyamides prepared by ring-opening reaction of the epoxy group with ethylenediamine (EDA) or ethanolamine (EA) had a higher affinity for moisture than those with hexamethylenediamine (HMD) or n-butylamine (n-BA), which might be ascribed to the distance of hydrophilic groups from the polyamide chain. Those polyamides having hydrophilic pendent groups decomposed upon heating at less than 200°C.     

Noninvasive assessment of significant left anterior descending coronary artery stenosis by coronary flow velocity reserve with transthoracic color Doppler echocardiography

BACKGROUND: Coronary flow reserve has been considered an important diagnostic index of the functional significance of coronary artery stenosis. With Doppler technique, it has been assessed as the ratio of hyperemic to basal coronary flow velocity (coronary flow velocity reserve [CFVR]) by invasive or semiinvasive methods with a Doppler catheter, a Doppler guide wire, and a transesophageal Doppler echocardiographic probe. Recent technological advancement in transthoracic Doppler echocardiography (TTDE) provides measurement of coronary flow velocity in the distal portion of the left anterior descending coronary artery (LAD) and may be useful in the noninvasive CFVR measurement. The purpose of this study was to evaluate the value of CFVR determined by TTDE for the assessment of significant LAD stenosis. METHODS AND RESULTS: We studied 36 patients who underwent coronary angiography for the assessment of coronary artery disease. The study population consisted of 12 patients with significant LAD stenosis (group A) and 24 patients without significant LAD stenosis (group B). With TTDE, coronary flow velocities in the distal LAD were recorded at rest and during hyperemia induced by intravenous infusion of adenosine (0.14 mg x kg(-1) x min(-1)) under the guidance of color Doppler flow mapping. Adequate spectral Doppler recordings of coronary flow in the distal LAD for the assessment of CFVR were obtained in 34 of 36 study patients (94%). The peak and mean diastolic coronary flow velocities at baseline did not differ between groups A and B (23.6+/-10.3 versus 22.9+/-6.6 cm/s and 16.4+/-8.6 versus 14.5+/-4.0 cm/s, respectively). However, the peak and mean coronary flow velocities during hyperemia in group A were significantly smaller than those in group B (35.6+/-16.3 versus 54.2+/-16.3 cm/s and 24.7+/-13.1 versus 37.9+/-13.0 cm/s, respectively; P<.01). There were significant differences in CFVR obtained from peak and mean diastolic velocity between groups A and B (1.5+/-0.2 versus 2.4+/-0.4 and 1.5+/-0.2 versus 2.6+/-0.4, respectively; P<.001). A CFVR from peak diastolic velocity <2.0 had a sensitivity of 92% and a specificity of 82% for the presence of significant LAD stenosis. A CFVR from mean diastolic velocity <2.0 had a sensitivity of 92% and a specificity of 86% for the presence of significant LAD stenosis. CONCLUSIONS: CFVR determined by TTDE is useful in the noninvasive assessment of significant stenotic lesion in the LAD.     

Effect of peripheral benzodiazepine receptor ligands on lipopolysaccharide-induced tumor necrosis factor activity in thioglycolate-treated mice

To investigate the effect of peripheral and central benzodiazepine receptor ligands on lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF) activity in mouse macrophages, three types of ligands, 4'-chlorodiazepam (pure peripheral), midazolam (mixed), and clonazepam (pure central), were compared. Midazolam and 4'-chlorodiazepam significantly suppressed LPS (1-microgram/ml)-induced TNF activity in thioglycolate-elicited mouse macrophages. In every concentration examined (0.001 to 100 microM), 4'-chlorodiazepam was the most effective agent, clonazepam was the least effective agent, and midazolam had an effect intermediate between those of the other two ligands. The peripheral benzodiazepine receptor ligands had a dose-dependent suppressive effect, and the 50% inhibitory concentrations were 0.01 microM for 4'-chlorodiazepam and 5 microM for midazolam. Concomitant use of PK 11195 (10 microM), an antagonist of the peripheral benzodiazepine receptor, reversed this suppressive effect with 4'-chlorodiazepam (10 microM) or midazolam (10 microM). PK 11195 showed this antagonistic effect in a dose-dependent manner. Intravenous 4'-chlorodiazepam (5 mg/kg of body weight) significantly suppressed LPS (100-micrograms)-induced TNF activity of sera (2 h postchallenge with LPS) from thioglycolate-treated mice. The present findings suggest that the peripheral benzodiazepine receptor plays an important role in modulating LPS-induced TNF activity in mouse macrophages.     

The first color education in Japan

The Meiji era (1868–1912) stands out as a period of radical modernization in Japan. For this reason, the Meiji Government paid special attention to the introduction of Western culture and civilization into modern Japanese society. Irozu (Color Chart) as the first attempt at color education in Japan resulted from one of these attempts at modernization. Iro-zu was a direct copy of Willson's Charts for object lessons which were prevalent in the United States at that time. Willson's Charts themselves had been substantiated by color science in the Western world, especially the works of the English chemist Field and the French chemist Chevreul. On the contrary, Iro-zu education almost abandoned the scientific meanings which Willson's Charts carried. According to the reformation of the educational system in 1879, Iro-zu education was gradually reduced. Though Iro-zu education lasted only five or six years, it has great importance as it marks the beginning of color education in Japan.     

The number of computers in a non-hierarchical system for Tokamak data processing

The data processing of a tokamak Ohmic heating experiment is summarized by a directed graph. A method which is a modification of the project-management technique PERT is developed and applied to this directed graph to analyse how many computers should be used for the data processing. An estimate of the number of computers is made for the data processor of the large tokamak JT-60.     

A new type of status data supervising instrument for high powermedium wave AM radio transmitter

A supervising instrument designed to measure the operating states of a high-power, medium-wave AM radio transmitter and its peripheral devices is described. The instrument can be used to measure the load impedance, output power, and efficiency of the final stage amplifier of the medium wave AM radio transmitter and can be used as a data logging and data analyzing instrument when the GP-1 B digital and analog interfaces are attached to the devices     

Reactive ion etching of III-V compounds using C2H6/H2

Reactive ion etching of InP, GaInAs and GaAs using a mixture of ethane and hydrogen, C₂H₆/H₂, is demonstrated for the first time. It has been found that by choosing optimum etching parameters one can obtain excellent vertical sidewalls as well as very smooth surfaces, keeping the etching rate at a convenient value of 20-60 nm/min     

Forced convection heat transfer to boiling helium in a tube

This paper describes a study carried out to obtain the heat transfer characteristics of liquid helium l in a vertical tube under forced convection conditions. The test section was a straight stainless-steel tube with a length of 8.5 cm and an id of 0.109 cm. Helium pressures ranged from 1.1 to 1.9 atm (0.11 to 0.19 MN m^?2) and qualities (vapour mass fractions) ranged from zero to 1.Results were correlated using conventional equations and compared with the data already obtained. The hysteresis observed in the nucleate boiling region is qualitatively discussed. The quality dependence of two-phase flow heat transfer was clearly observed during an increase, but not during a decrease, of heat flux or quality.