In-plane detection of scattered light from a minute particle using a resin-based light waveguide incorporated with a microfluidic channel

An optical sensor combined total analysis system (TAS) is thought to be one of the most powerful functional elements needed to realize a “ubiquitous human healthcare” system. In accordance with this concept, we have proposed a fundamental structure of detecting side scattered light from a minute cell or particle running along a microfluidic channel, partially utilizing the channel filled with water or saline solution as a light waveguide. Based on this concept, we have fabricated a trial-manufactured optical TAS chip and carefully evaluated its side scattered light measuring performance in in-plane direction, supplying and detecting visible laser power by using multiple optical fibers and their precise positioning mechanisms. We have successfully obtained experimental results of both transmitted light power change and that of side scattered light, and we confirmed that there was a strong relationship between their signal waveforms. Furthermore, we have developed a hybrid numerical calculation method on the basis of the finite-difference time-domain method, in addition to the beam propagation method. Based on this hybrid method, we tried to compare results between the experimental inverse pulse of transmitted light and a pulse of side scattered light, and those based on numerical calculations. Excellent qualitative accordance was obtained between the inverse pulse of numerical and experimental results. In contrast, the experimental pulse of side scattered light indicated a considerably spread base in comparison to the numerical results.     

Synthesis of the Orthorhombic Phase of ZrO2

Single-phase orthorhombic ZrO₂ was prepared by quenching from high temperature and high pressure. The lattice parameters are a₀=0.5042, b₀=0.5092, and c₀=0.5257 nm; the calculated density is 6.09 Mg·m⁻³. This phase is metastable under atmospheric pressure and reverts to the monoclinic phase either on heating above 300°C or when it is ground in a mortar.     

Analysis of residual vulcanization accelerators in baby bottle rubber teats

An analytical method was established for the determination of dialkyldithiocarbamates (DTCs) in chloroform-acetone extracts from rubber teats for baby bottles. DTCs in the extracts were derivatized into ethyl esters and analysed by gas chromatography employing nitrogen-phosphorus detection. Dimethyldithiocarbamate and diethyldithiocarbamate were detected at levels up to 3.2 micrograms/g rubber and up to 4.6 micrograms/g rubber (as dithiocarbamic acid), respectively, in the extracts from commercially available isoprene rubber tests. DTCs can form secondary amines by acid hydrolysis, although the levels of DTCs in the extracts only made a minor contribution to the total level of measured secondary amine precursors.     

Site‐Selective Iron(III) Chloride‐Catalyzed Arylation of 4‐Aryl‐4‐methoxy‐2,5‐cyclohexadienones for the Synthesis of Polyarylated Phenols

The iron(III) chloride‐catalyzed Friedel–Crafts arylation of 4‐aryl‐4‐methoxy‐2,5‐cyclohexadienones, which were easily prepared by the phenyliodine(III) diacetate (PIDA)‐mediated oxidation of 4‐arylphenols in methanol, proceeded site‐selectively to form meta‐terphenyl (2,4‐diarylphenol) derivatives in good yields. The subsequent PIDA‐mediated oxidation and iron(III) chloride‐catalyzed Friedel–Crafts arylation of the resulting products gave the corresponding 2,4,6‐triarylphenol derivatives. The present method provides useful highly substituted polyarylated compounds.

     

A circulating current control scheme for multiple three‐level NPC inverter systems

In recent years, motor drive systems for steel rolling mills have been steadily increasing in capacity. In particular, the development of three‐level NPC (Neutral Point Clamped) inverters is now focusing on the replacement of cycloconverters. In order to satisfy such a requirement, in this paper a multiple three‐level NPC inverter system is proposed. The configuration consists of two three‐level NPC inverters with the same configuration connected in parallel by current limiting reactors. In this case, the circulating current flowing between the two three‐level NPC inverters must be controlled to prevent a decrease in the maximum output capacity. In particular, a new method for control of the circulating current is a major topic of discussion. The method is based on space voltage vector‐based PWM (Pulse Width Modulation) control for the three‐level NPC inverters and the circulating current is controlled by adjusting the output durations of the respective space voltage vectors. In this method the circulating current controller can be decoupled from the motor current controller. Therefore, it is possible to design the different controllers independently. In addition, the experimental results obtained using an induction motor show that the circulating current can be reduced to within 2% of the rated motor current when the motor current response exceeds 1000 rad/s. © 2001 Scripta Technica, Electr Eng Jpn, 136(2): 38–48, 2001     

Preparation and Characterization of LaxC60 Thin Films Fabricated by Layer-by-Layer Deposition

A modification of physical properties of solid-state C₆₀ when La was doped to C₆₀ thin film as a trivalent metal was examined. the thin film was fabricated by using Layer-by-Layer deposition technique with the multi-sources evaporation system. We found that the C₆₀ film changes its electrical character from the insulator to the semiconductor rapidly upon La doping. the temperature dependence of the electrical conductivity is semiconductive with the activation energy of about 0.3eV.     

Effect of concurrent use of ondansetron hydrochloride and dexamethasone against nausea and vomiting in lung cancer patients receiving cisplatin

We examined the efficacy of concurrent use of ondansetron hydrochloride and dexamethasone, and the effective dose of dexamethasone against nausea and vomiting in lung cancer patients receiving chemotherapy including single high dose cisplatin. The study was carried out on total of 44 courses of chemotherapy in either initial onset or recurrence of lung cancer. The patients were given 4 mg of ondansetron injection on the day of cisplatin injection (Day 1), and 4 mg/day of ondansetron tablet for Days 2 to 4. These patients were randomly allocated into 2 groups, i.e., those who, on Day 2, concomitantly received 10 mg of dexamethasone (D10 Group, 22 courses) or 20 mg (D20 Group, 22 courses), for comparing the antiemetic effects in a different concomitant dose of dexamethasone. An efficacy rate of 70% or more was achieved in each group for acute emesis on Day 1. The efficacy rate was 80% or above for emesis on Day 2 when dexamethasone was concurrently administered, and Days 3 and 4 in both groups. No significant difference was observed between the groups. A higher complete suppression rate against nausea was seen in D20 Group even though the difference from D10 Group was not significant. Furthermore, food intake rate on Day 2 was significantly better in D20 Group. However, in the cases that were graded effective or markedly effective for acute emesis on Day 1, the efficacy rate was also high in both groups through Days 2-4. It was notable that the efficacy rate of Days 2-4 was 100% in D2 Group. The high efficacy rate was shown in male patients regardless of which dose of dexamethasone was used. However, control of emesis was unfavorable in female patients on Day 1 and was still unfavorable even though dexamethasone was combined from Day 2. We considered from the above results that 10 mg/day of concurrent dexamethasone is sufficient in suppression of delayed emesis on Day 2. However, in order to improve nausea or food intake, or to suppress emesis in patients who are highly likely to show unfavorable control for Day 2 and onward, 20 mg/day should also be effective.     

Interaction between the amino-terminal SH3 domain of CRK and its natural target proteins

CRK is a human homolog of chichen v-Crk, which is an adaptor protein. The SH2 domain of CRK binds to several tyrosine-phosphorylated proteins, including the epidermal growth factor receptor, p130(Cas), Shc, and paxillin. The SH3 domain, in turn, binds to cytosolic proteins of 135-145, 160, 180, and 220 kDa. We screened expression libraries by Far Western blotting, using CRK SH3 as a probe, and identified partial cDNA sequences of four distinct proteins, including C3G, DOCK180, EPS15, and clone ST12. The consensus sequence of the CRK SH3 binding sites as deduced from their amino acid sequences was Pro+3-Pro+2-X+1-Leu0-Pro-1-X-2-Lys-3. The interaction of the CRK SH3 domain with the DOCK180 peptide was examined with an optical biosensor, based on the principles of surface plasmon resonance. A low dissociation constant of the order of 10(-7) resulted from a high association rate constant (kassoc = 3 x 10(4)) and low dissociation rate constant (kdiss = 3 x 10(-3)). All CRK-binding proteins except clone ST12 also bound to another adaptor protein, Grb2. Mutational analysis revealed that glycine at position +1 of ST12 inhibited the binding to Grb2 while retaining the high affinity binding to CRK SH3. The result suggests that the amino acid at position +1 also contributes to the high affinity binding of the peptides to the SH3 domain of Grb2, but not to that of CRK.     

An attempt to add biological functions by genetic engineering in order to produce high-performance bioreactor cells for hybrid artificial liver: transfection of glutamine synthetase into Chinese hamster ovary (CHO) cell

Ureteral triplication is a rare congenital anomaly of the upper urinary tract. It is reported to be associated with an increased incidence of congenital anomalies as well as a predisposition to infection and calculus formation. We report a case of type 1 variant of ureteral triplication associated with vesicoureteral reflux into lower and mid pole ureters in a solitary kidney. To our knowledge ureteral triplication in a solitary kidney has not been described previously.