Immobilization of enzymes on electrostatic medium of positively charged dimethylamino nylon gel

Urease and glucose oxidase were immobilized by positively charged nylon gel matrix made from dimethylaminated nylon. The stability of the immobilized enzyme after preheating and incubation in organic solvent were measured and compared with that of native enzymes. Also, pH dependency of the immobilized enzymes was examined. The pH activity curves of the immobilized enzyme shift toward a low pH compared with that of the native enzyme. Using the pH difference, the electrostatic potential of the positively charged nylon gel was estimated. The estimated values of the positively charged gel were +90 and +102 mV for the immobilized urease and immobilized glucose oxidase, respectively. In the presence of buffer salt, they decreased to +30 and +24 mV, respectively. © 1992 John Wiley & Sons, Inc.     

Calculation of manufacturing tolerances of an electron gun by apseudo-three dimensional field analysis

A method of calculating the electric field of nearly rotationally symmetric electrodes has been developed. The field is calculated by superposing virtual surface charges on the electrodes. The method has the advantages of speed and sensitivity to deviations from symmetry. The method is used to calculate the tolerances of the electrodes in an electron gun to deviations of the holes from roundness. The shift of the beam spot due to an asymmetrical chamfer is calculated by tracing the electron beam using the electric fields calculated by this method. The calculated tolerance gives good agreement with the empirical tolerance. The calculated magnitude of the shift agrees with experimental results for a test electron gun     

Formation and Photoreaction of PbI2, HgI2, and BiI3 Layered Ultrasmall Particles

Formation of ultrasmall particles of PbI₂ in methanol was observed by means of stroboscopic stopped-flow spectroscopy. Pulse-laser induced electron transfer from PbI₂, HgI₂, and BiI₃ to viologens was measured for various laser intensities and for various viologen concentrations. The electron transfer yields were 0.24, 0.08, and 0.03 for HgI₂, PbI₂, and BiI₃, respectively. The laser-intensity dependence differed from the previous observation for CdS and showed that the low yield is not attributable to the direct electron-hole recombination in the particle.     

Neural Model Approach to the Basic Law of Psychophysics

Stevens’ law, which is one of the well-known psychophysical laws, suggests that the perceived intensity R of a biological system is proportional to the power of the stimulus strength I, R ∝ I ⁿ . In order to realize a self-sustainable system that adapts to changes of the environment, it is important to understand the neural mechanism behind this law. Here, we propose a new neural scheme based on the shunting short-term memory (STM) model with the physiological properties of the nervous system, and examine the relation between the neural system and Stevens’ law through computer simulations of the firing rate f with respect to the stimulus strength I. The simulations showed that the feedback-inputting connectivity plays an important role in reproducing the n > 1 and n < 1 cases of Stevens’ law.     

Dietary medium- and long-chain triacylglycerols accelerate diet-induced thermogenesis in humans

This study investigated the effects of a liquid meal containing medium- and long-chain triacylglycerols (MLCT) on diet-induced thermogenesis (DIT) and was conducted in double-blind cross-over manner. Twenty subjects participated in this examination. The subjects consumed the liquid meal, which was made with 14 g of canola oil (LCT, long-chain triacylglycerols) or MLCT containing about 12% medium-chain fatty acids (MCFA). Oxygen consumption and carbon dioxide production were measured by indirect calorimetry. Resting energy expenditure (REE) was determined based on there parameters, applying the equation of Weir. Increase in DIT after ingesting the liquid meal with MLCT during 6h was significantly greater than with LCT (P<0.05). The results suggest that the substitution of MLCT for cooking oil is useful to control body weigh and fat in subjects.     

A 10-Gb/s data-pattern independent clock and data recovery circuit with a two-mode phase comparator

A clock and data recovery (CDR) circuit with a novel two-mode phase comparator is proposed. The 10-Gb/s CDR integrated circuit (IC) operates both for consecutive identical digits (CID) and data transition density variations. This advance is achieved through the use of our novel two-mode phase comparator, which enables us to determine an optimal phase-locked loop parameter for various data patterns. Experimental results show that the jitter generation of the CDR IC is less than 7 pspp for a 2/sup 7/-1 pseudorandom bit sequence with up to 1024 CIDs. The results also show that the jitter transfer and jitter tolerance are unaffected by data transition density factors of between 1/8 and 1/2.     

Analysis of Field Emission Properties of Carbon Nanocoils for Imaging Materials

Carbon nanotubes and nanocoils are expected as the charging materials and electron gun for the imaging devices. It is synthesized for carbon nanocoils with different diameters by the catalytic thermal decomposition of acetylene using iron-indium-tin-oxide catalysts. It is found that the turn-on voltage is decreased by decreasing the average diameter of the grown carbon nanocoils. The turn on voltage of as low as 30 V at the electrodes' gap of 130 μm has been achieved when the coil diameter is decreased to 60 nm. The calculation for the concentration of the electric field on the coil surface has been performed using a finite element method. It is obtained that the strength of electric field around the top ring of a coil is increased with the decrease of the tubular diameter of the coil and has a similar value for that at the tip of a carbon nanotube, suggesting that the efficiency of the field emission from nanocoils would be higher than that from nanotubes. These results can explain the good stability of field emission from carbon nanocoils.     

50 Gbit/s low-jitter dynamic decision circuit using Cbc compensation and semi-feed forward techniques

A new low-jitter dynamic decision circuit is designed and fabricated using InP/InGaAs HBTs. Cbc compensation transistors and semi-feed forward loads are adopted to eliminate waveform distortion and residual double trace, respectively. A fabricated decision IC achieves error-free operation and wide eye opening for 50 Gbit/s 2/sup 31/-1 PRBS with 0.68 W power dissipation. Its RMS and peak-to-peak jitter of output data are 0.59 and 4.1 ps, respectively.     

Preparation of ZnS thin films from solution mist by laser irradiation

A new type of laser chemical vapour deposition process, in which the reactants are incorporated in the mist of the solvent, is proposed. It is applicable to prepare high-quality thin films from reactants having a low vapour pressure. By using a continuous wave CO₂ laser, ZnS thin films, consisting of c-axis oriented ultrafine microcrystallites, have been prepared.     

A case report of cardiac failure caused by the new anti-neoplastic agent 'carboplatin'

Carboplatin is one of most commonly used chemotherapeutic agents in clinical oncology practice. We presented a case of subacute cardiotoxicity supposedly due to carboplatin. A patient with ovarian cancer had been treated with carboplatin based chemotherapeutic agent for about a month before surgery. Although she had not shown symptoms of cardiac failure, severe pulmonary edema developed immediately after general anesthesia. It disappeared within a week. For three days following the administration of carboplatin alone for two weeks after surgery, arrhythmias (SVT, SVPB and VPB) and hypotension appeared. Symptoms of congestive heart failure, resembling dilated cardiomyopathy, lasted for one month. It required about two months to restore the normal cardiac functions. Carboplatin seems to have infrequent but possible cardiotoxicity as many other chemotherapeutic agents.