Thiobarbituric acid-reactive substances from peroxidized lipids

The thiobarbituric acid (TBA) reaction was performed on linoleic acid 13-monohydroperoxide, autoxidized fatty esters, edible fats and oils, rat liver microsomal lipids, and on human erythrocyte ghost lipids in order to determine which substances from peroxidized lipids are TBA-reactive. The reaction was carried out in 2% acetic acid containing butylated hydroxytoluene using two different reaction modes: a one-step mode which involves heating at 100°C, and a two-step mode which involves first treatment at 5°C and subsequent heating at 100°C. Yields of the red 1∶2 malonaldehyde/TBA adduct, as estimated by absorbance, fluorescence intensity and high-performance liquid chromatography, were much higher than the malonaldehyde content as determined by direct chemical analysis. Yields of red pigment obtained by the two-step mode were slightly higher than those obtained by the one-step mode. Pigment yields were dramatically increased by addition oft-butyl hydroperoxide. Red pigment formation from alkenals and alkadienals was similarly enhanced by the two-step mode or by addition oft-butyl hydroperoxide, whereas pigment formation from malonaldehyde was not. It appears likely that a component of the total red pigment formed from the peroxidized lipids was due to aldehyde species other than malonaldehyde.     

Study of the Al-Al2O3 Bond Interface

The adhesion of an aluminum evaporation layer onto an alumina substrate was strong despite attack from the liquid gold-silicon eutectic during an integrated circuit chip attachment process. Evidence of the resultant layer, which contained an oxygen concentration gradient from the interface into the Al, is presented.     

Finite spectrum assignment of systems with general delays

This article presents a new framework for dealing with pure and distributed delays simultaneously and impartially as general delays in algebraic finite spectrum assignment. The framework based on an important property common to general delays gives a sufficient condition for finite spectrum assignability of scalar systems with several general delays and a design method of a controller achieving finite spectrum assignment. Especially in algebraic control theory for delay systems, pure and distributed delays have never been dealt with simultaneously and impartially. The framework is significantly important also for multidimensional system theory because its potential applicability to the discussion on systems with general delays, i.e. the possibility that especially distributed delay operators are used as variables for describing multidimensional systems, is clarified for the first time.     

Automatic generation of tourism quiz using blogs

The one-way information communication provision does not impress listeners well. As an efficient way, Question & Answer can not only help listeners to comprehend the content of information but also help information providers understand the response of listeners. However, it is not easy for everyone to create suitable questions. In this paper, we propose an automatic quiz generation system using tourism blogs. The system can generate quizzes by extracting feature words of the topic keyword from blogs. Our purpose is to help tourism information providers to advertise their tourism events in an interactive way, in order to impress tourists. When compared with other methods of quiz generation, we demonstrate that our method is more suitable for information communication provision.     

Sulfide capacities of CaO-CaF2-CaCl2 melts

The sulfide capacity of CaO-CaF₂-CaCl₂ slag was determined at temperatures from 1000 °C to 1300 °C by equilibrating molten slag, molten silver, and CO-CO₂-Ar gas mixture. The sulfide capacity increases with replacing CaCl₂ by CaF₂ in slags of constant CaO contents. The sulfide capacity also increases with increasing temperature as well as with increasing CaO content at a constant ratio of CaF₂/CaCl₂ of unity. A linear relationship between the sulfide capacity and carbonate capacity in literature was observed on a logarithmic scale. SIMEON SIMEONOV, formerly Visiting Research Fellow, Institute of Industrial Science, University of Tokyo. TOSHIHIKO SAKAI, formerly Research Fellow, Institute of Industrial Science, University of Tokyo.     

A new positive-type photoreactive polyimide precursor using 1,4-dihydropyridine derivative

A novel positive-type polyimide precursor (BPDA/DDE) has been developed and examined. It is synthesized by the polycondensation of biphenyltetracarboxylic acid dianhydride and 4,4′-diamino-diphenyl ether, based on systems composed of dimethyl 1,4-dihydro-2,6-dimethyl-4-(2-nitrophenyl)-3,5-pyridinecarboxylate (nifedipine). Nifedipine photoconverted quantitatively to 4-(2′-nitrosophenyl)-2,3-dicarboxymethyl-3,5-dimethylpyridine (NDMPy) in a polyimide precursor film. It has been confirmed that nifedipine and NDMPy in the film act as a dissolution inhibitor and as a disolution promotor, respectively. The dissolution inhibition and promotion mechanisms were further investigated and subsequently expressed as follows:

• (1) Dissolution inhibition is due to resistivity of the polyimide precursor to an alkaline aqueous solution through intermolecular hydrogen bonding between — COOH in the polymer structure and — NH — in nifedipine.
• (2) Dissolution promotion is due to the hydrogen bond-breaking by photoconversion from nifedipine to NDMPy and the newly formed intermolecular complex between the COOH and ? N? in NDMPy.

The photoreactive polyimide precursor (BPDA/DDE), including 25wt% nifedipine, shows a 170mJ/cm² sensitivity and a 5.5 γ value.     

A new combined system of active and passive filters to obtain harmonic compensation for large-capacity thyristor converters

Shunt passive filters, which are connected in parallel to harmonic-producing loads, have been used widely for harmonics suppression in power systems because of low cost and high efficiency. However, they have such inherent problems as series and parallel resonance. On the other hand, shunt active filters, which are also placed in parallel, have such an inherent problem as initial and running costs are high compared with those of shunt passive filters. To solve these inherent problems in shunt passive and shunt active filters, the authors have proposed a combined system of a shunt passive filter and a small rated series-active filter. The purpose of this paper is to reduce the required rating of the series-active filter, considering a practical application of the combined power filter to harmonic compensation for large-capacity thyristor converters. The points are summarized as follows:

• 1 The required rating of the series-active filter can be reduced less than one-tenth by connecting a series-resonant circuit in parallel to the secondary of current transformer.
• 2 It is clarified theoretically and verified experimentally that compensation characteristics of the new combined system are equivalent to those of the already-proposed system with no series-resonant circuit.

     

Highly sensitive surface plasmon resonance immunosensor for parts-per-trillion level detection of 2,4,6-trinitrophenol

A new surface plasmon resonance (SPR) immunosensor has been demonstrated for the determination of 2,4,6-trinitrophenol (TNP) based on the principle of indirect competitive immunoreaction using trinitrophenol–bovine serum albumin (TNP–BSA) conjugate and anti-TNP antibody. TNP–BSA conjugate was immobilized on a SPR chip by physical adsorption. TNP in solution competes with the immobilized TNP–BSA conjugate for binding with anti-TNP antibody, which inhibit the immunoreaction between TNP–BSA conjugate and anti-TNP antibody. The dependence of the inhibition to the concentration of TNP was utilized for quantification of TNP. Regeneration of the sensing surface for multiple analyses can be effected using pepsin solution. The sensor exhibited excellent sensitivity for the detection of TNP in a wide concentration range from 10 ppt to 100 ppb and has promising analytical characteristics, which can be extended to the determination of nitroaromatic explosive compounds for application to on-site detection of landmines.     

A Microprocessor-Based Current Controller with an Internal Current-Rate Loop for Motor Drives

A new current-control method that is suitable for microprocessor-based speed regulation of motor drives is described. The method achieves fast-response and high-accuracy performance by using a major current loop and an internal current rate loop. The former loop is used to control precisely the mean value of the motor current by employing a current feedback signal obtained from a smoothing filter of the rippled current. The latter loop is used to stabilize the major loop with a high gain and to limit the variation rate of the motor current by employing the current feedback signal obtained from the instantaneous current without time delay. A current controller using a microprocessor was trail-manufactured and tested with a thyristor-converter-driven dc motor. It was found that fast-controlled current response can be obtained, even with a relatively long sampling period.     

Sequential molecularly targeted drug therapy including axitinib for a patient with end‐stage renal failure and metastatic renal cell carcinoma

A 62‐year‐old male patient with end‐stage renal disease and metastatic renal cell carcinoma (RCC) was referred to our hospital. Sequential targeted therapy consisting of sorafenib, sunitinib, and everolimus was administered, but the patient's disease gradually progressed. Axitinib was subsequently administered at a decreased dose of 6 mg/day for 2 weeks, after which the dose was escalated to 10 mg/day. Axitinib therapy was maintained for a total of 6 months without severe adverse effects. Sequential molecularly targeted drug therapy including axitinib, with careful monitoring, is one possible treatment option for patients with metastatic RCC with renal impairment.