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81.
Polychlorinated biphenyls (PCBs) that are present in transformer oil are a common global problem because of their toxicity and environmental persistence. The development of a rapid, low-cost method for measurement of PCBs in oil has been a matter of priority because of the large number of PCB-contaminated transformers still in service. Although one of the rapid, low-cost methods involves an immunoassay, which uses multilayer column separation, hexane evaporation, dimethyl sulfoxide (DMSO) partitioning, antigen-antibody reaction, and a measurement system, there is a demand for more cost-effective and simpler procedures. In this paper, we report a DMSO partitioning method that utilizes a microfluidic device with microrecesses along the microchannel. In this method, PCBs are extracted and enriched into the DMSO confined in the microrecesses under the oil flow condition. The enrichment factor was estimated to be 2.69, which agreed well with the anticipated value. The half-maximal inhibitory concentration of PCBs in oil was found to be 0.38 mg/kg, which satisfies the much stricter criterion of 0.5 mg/kg in Japan. The developed method can realize the pretreatment of oil without the use of centrifugation for phase separation. Furthermore, the amount of expensive reagents required can be reduced considerably. Therefore, our method can serve as a powerful tool for achieving a simpler, low-cost procedure and an on-site analysis system.  相似文献   
82.
Complete and rapid peptide and glycopeptide mapping of a mouse monoclonal immunoglobulin (IgG2b) were carried out by liquid chromatography/electrospray ionization ion trap-mass spectrometry/mass spectrometry (LC/ ESI IT-MS/MS). It was possible to obtain spectra of a minor glycopeptide at a quantity as low as 1.8 pmol. Reduced and carboxymethylated mouse antidansyl monoclonal IgG2b (RCM-IgG2b) was digested with lysyl-endopeptidase. Proteolytic peptides were subjected to capillary HPLC separation followed by analysis with an ion trap mass spectrometer. The complete amino acid sequence of the IgG2b was characterized by using LC/ ESI IT-MS/MS. The structures of 12 different types of O-linked oligosaccharides attached to Thr-221AH in the hinge region and those of three major types of N-linked oligosaccharides attached to Asn-297H have been characterized.  相似文献   
83.
The YBaCu-O and Bi(Pb)SrCaCu-0 system superconductor coatings by thermal spraying are described. YBaCu-O system superconductor coatings are sprayed by using perovskite type and non-perovskite type powders. As sprayed coatings are not superconducting and there is no perovskite structure even when perovskite type powders are used, but they become superconducting after heat treatment in air. An electrochemical method was also employed, to obtain a high quality superconductor applying an electric field treatment. Bi(Pb)SrCsiCu-0 system superconductor coatings are sprayed by changing the starting composition. As-sprayed coatings were not superconducting, but they become superconducting after heat treatment in air like the YBaCu-O system. The Tc of the sprayed coatings using (Bi1-xPbx)5Sr3Ca2Cu3-O powders is higher than the Tc of sprayed coatings using (Bi1-xPbx) 2Sr2Ca2Cu3-O powders.  相似文献   
84.
In a solidly mounted piezoelectric thin film resonator (SMR), acoustic waves propagate not only in the thickness direction but also in the lateral direction. In this study, we analyzed the acoustic wave in the SMR-type piezoelectric thin film resonator and derived the dispersion relation between the lateral wave number and frequency, considering wave propagation in the lateral direction. The lateral wave number was shown to be a complex number due to the leak of the acoustic energy to a substrate. It also was shown that the Q factor could be calculated from the complex cutoff frequency, and it becomes higher when the number of quarter-wave (lambda/4) layers increases. Using the dispersion relation, the trapped-energy resonant modes of an SMR were analyzed, considering the boundary conditions at the edge of the electrode.  相似文献   
85.
This paper traces the history of sewer construction in Japan. The first sewers were built for flood control, and as late as the end of the Second World War there were only six cities enjoying sewer systems with treatment facilities. Rapid industrialization increased pollution problems and led to accelerated sewer development. Advances in the technology of sewage treatment are outlined. Today 30% of Japan's population is served by sewer systems, and identifying cost‐effective means of increasing that proportion is a major priority. The Experimental Sewer System, developed in Tokyo, is described. Finally, a new method for the estimation of peak flow in sewer pipes, entitled grid analysis, is presented.  相似文献   
86.
The stereoisomeric composition of the copulation release pheromone of the azuki bean weevil, Callosobruchus chinensis L., was determined to be R:S = 3.3–3.4:1 by the 2D-Ohrui–Akasaka method.  相似文献   
87.
Heart dysfunction and liver disease often coexist. Among the types of cardiohepatic syndrome, Type 2 is characterized by the chronic impairment of cardiac function, leading to chronic liver injury, referred to as congestive hepatopathy (CH). In this study, we aimed to establish a rat model of CH secondary to right ventricular hypertrophy (RVH) related to monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). Fifty male Wistar rats were divided into four groups and randomly assigned to control and experimental groups. Three experimental groups were submitted to intraperitoneal MCT inoculation (60 mg/kg) and were under its effect for 15, 30 and 37 days. The animals were then sacrificed, obtaining cardiac and hepatic tissues for anatomopathological and morphometric analysis. At macroscopic examination, the livers in the MCT groups presented a nutmeg-like appearance. PAH produced marked RVH and dilatation in the MCT groups, characterized by a significant increase in right ventricular free wall thickness (RVFWT) and chamber area. At histological evaluation, centrilobular congestion was the earliest manifestation, with preservation of the hepatocytes. Centrilobular hemorrhagic necrosis was observed in the groups exposed to prolonged MCT. Sinusoidal dilatation was markedly increased in the MCT groups, quantified by the Sinusoidal Lumen Ratio (SLR). The Congestive Hepatic Fibrosis Score and the Centrilobular Fibrosis Ratio (CFR) were also significantly increased in the MCT30 group. Hepatic atrophy, steatosis, apoptotic bodies and, rarely, hydropic swelling were also observed. SLR correlated strongly with CFR and RVFWT, and CFR correlated moderately with RVFWT. Our rat model was able to cause CH, related to monocrotaline-induced PAH and RVH; it was feasible, reproducible, and safe.  相似文献   
88.
Effects of Bi-doping in PbTe liquid-phase epitaxial layers grown by the TDM-CVP have been investigated. For Bi concentration in the solution, xBi, lower than 0.2 at.%, Hall mobility is low. In contrast, for xBi>0.2 at.%, Hall mobility is high, while carrier concentration is in the range 1017 cm−3. However, ICP emission analysis shows that, for xBi=1.0 at.%, Bi concentration in epitaxial layer is NBi=2.3–2.7×1019 cm−3.These results indicate that Bi behaves not only as a donor but also as an acceptor; the nearest neighbor or very near DA pairs are formed. Carrier concentration for Bi-doped layers takes a minimum value at a Te vapor pressure of 2.2×10−5 Torr for growth temperature 470°C, which is coincident with that of the undoped PbTe. And broad contact pn junctions with highly Bi-doped layers easily cause laser emission compared to undoped junctions. The result suggests that the nearest lattice site Bi–Bi DA pairs behave as strong radiative centers in PbTe.  相似文献   
89.
Hybrid Vehicles (HEVs) and Electric Vehicles (EVs) improve drive efficiency and reduce CO2 emissions by regenerative braking and operating the engine under optimum conditions. It is desirable to decrease the motor size and increase the maximum torque to minimize driving units. For these purposes, motors employing permanent magnets are now commonly used. The motor driving systems of HEVs and EVs must operate over variable speed ranges of up to 1:5. Over this large range, smooth, silent operation is desirable and important. The skew method is often adopted to ensure a smooth start and stop and silent operation by reducing torque ripple. However, this method possibly causes noise and motor vibration. This paper describes the mechanism of torsional resonance noise and vibrations arising from the skew method and a countermeasure to decrease them by optimizing the skew phase distribution on the rotating axis.  相似文献   
90.
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