A voltage-source PWM rectifier-inverter with feedforward control of instantaneous power

In general, diode rectifiers with electrolytic capacitors on the dc side have been used as dc power supplies for voltage-source inverters. Rectifiers of this type, however, cause many problems such as poor power factor and harmonics. Recently, voltage-source PWM rectifier-inverters have been studied to provide the following advantages: (1) harmonic-free on both ac sides; (2) unity power factor on the input ac side; (3) power flow of either direction or power regeneration; (4) reduction of the dc capacitor. However, it is difficult for a conventional voltage-source PWM rectifier-inverter to regulate the capacitor voltage on transient states because it has only a voltage feedback loop. This paper describes a voltage-source PWM rectifier-inverter with feedforward control of instantaneous power. Based on the pq theory, the instantaneous power which is calculated in the control circuit of the inverter is fed forward to the control circuit of the rectifier. The feedforward control of instantaneous power contributes greatly to sufficiently suppress voltage fluctuation of the dc capacitor on transient states. Transient characteristics are discussed, and some interesting experimental results of a laboratory model are shown.     

Charged amino acids at the carboxyl-terminal portions determine the intracellular locations of two isoforms of cytochrome b5

Outer mitochondrial membrane cytochrome b5 (OMb), which is an isoform of cytochrome b5 (cyt b5) in the endoplasmic reticulum, is a typical tail-anchored protein of the outer mitochondrial membrane. We cloned cDNA containing the complete amino acid sequence of OMb and found that the protein has no typical structural feature common to the mitochondrial targeting signal at the amino terminus. To identify the region responsible for the mitochondrial targeting of OMb, various mutated proteins were expressed in cultured mammalian cells, and the subcellular localization of the expressed proteins was analyzed. The deletion of more than 11 amino acid residues from the carboxyl-terminal end of OMb abolished the targeting of the protein to the mitochondria. When the carboxyl-terminal 10 amino acids of OMb were fused to the cyt b5 that was previously deleted in the corresponding 10 residues, the fused protein localized in the mitochondria, thereby indicating that the carboxyl-terminal 10 amino acid residues of OMb have sufficient information to transport OMb to the mitochondria. The replacement of either of the two positively charged residues within the carboxyl-terminal 10 amino acids by alanine resulted in the transport of the mutant proteins to the endoplasmic reticulum. The mutant cyt b5, in which the acidic amino acid in its carboxyl-terminal end was replaced by basic amino acid, could be transported to the mitochondria. It would thus seem that charged amino acids in the carboxyl-terminal portion of these proteins determine their locations in the cell.     

Urethral recurrence of bladder cancer 16 years after total cystectomy. A case report]

A 74-year-old man was admitted to our hospital. Diagnosis of invasive bladder cancer was made and a total cystectomy was performed on January, 30, 1980. Histological examination showed transitional cell carcinoma, grade 2, pT1 is N0M0. After 16 years, when he suffered left femur, he had right inguinal lymphnode swelling. On the biopsy of the inguinal mass, histology was transitional cell carcinoma. The urethral washing cytology was positive. Lung CT scan dem onstrated multiple lesions. He was diagnosed of the urethral recurrence, right inguinal lymphnode metastasis and lung metastasis of bladder cancer. This case is the 5th case of urethral recurrence of bladder cancer following cystectomy in our hospital.     

Application of a bio-electrochemical reactor process to direct treatment of metal pickling wastewater containing heavy metals and high strength nitrate.

The fundamental performance of a bio-electrochemical reactor for the direct treatment of metal pickling wastewater was investigated experimentally. In the reactor, carbon anode and cathode were installed. On the cathode, denitrifying microorganisms were immobilized. Continuous experiments were carried out by feeding a synthetic wastewater containing nitrate and binary heavy metal ions, copper and lead, under different operating conditions. Acetate as well as the electric current was supplied at the minimum amount for stoichiometry of the dissimilatory denitrification reaction. The results indicated that the dissolved copper and lead removal, denitrification and neutralization could be achieved simultaneously in a single bio-electrochemical reactor. The dissolved heavy metals were removed by electrochemical deposition on cathode and by the other phenomena such as the formation of insoluble suspensions and the sorption on suspended bacterial sludge. Denitrification proceeded effectively with the utilization of both added acetate and hydrogen gas generated by electrolysis of water. The pH value increased up to around neutral due to the occurrence of denitrification in the reactor, although the influent pH was less than 3. The removal efficiencies of heavy metals and nitrate increased with increasing the current density. The applied electric current was indispensable for sustaining the stable treatment in the reactor.     

VLIW DSP for mobile applications

We have developed a new digital signal processor (DSP) core for handheld terminals, the SPXK5 performance and flexibility, is compatible with high-level languages, and its architecture features low-power consumption. We describe the SPXK5 architecture and its performance in DSP applications. We also consider the question of application-specific enhancements. Such architecture enhancements as add-compare-select instructions or coprocessors for the Viterbi (1995) decoding algorithm are employed in some programmable DSPs, and for video codecs, other architectures include either single-instruction multiple-data (SIMD) instructions or media coprocessors. While such application-specific enhancements are valuable when their applications are actually in use, they do nothing to enhance the performance of other applications, and the more they are added, the greater the increase in chip size and energy requirements. In other words, for handheld terminals, such enhancements need to be chosen in a careful and balanced way. We have done this in developing the SPXK5, in which a wide range of signal processing algorithms are efficiently implemented     

亚洲城市主义——公共街道中住区生活的动态性之解读

针对亚洲文脉下的高密度城市环境,提出“亚洲城市主义”作为一种新的研究和设计模式,并提出“一席之地”的概念作为环境设计中的焦点。研究关注的是“街道社会生态”,特别是在某一时刻街道上循环的事物、活动和空间结构的一幕最小的互相依赖图景,称作“社会即景”,倡导为高密度城市环境作契合文化内涵的设计。     

Coexpression of hepatocyte growth factor and c-Met proto-oncogene product in synovial sarcoma

Hepatocyte growth factor (HGF) is a heterodimeric polypeptide growth factor that has pleiotropic roles, including those of mitogen, motogen and morphogen. The HGF receptor is characterized as a c-Met proto-oncogene product (c-Met), which is a heterodimeric tyrosine kinase receptor. Hepatocyte growth factor acts as a mediator between the mesenchymal and epithelial tissues because HGF is produced by mesenchymal cells and c-Met is mainly expressed on various epithelial cells. Furthermore, the HGF/c-Met system plays an important role in embryogenesis and the regeneration of various organs. Synovial sarcoma (SS) are unique sarcoma that show epithelial differentiation, but little is known about their histogenesis. The expression of HGF and c-Met was examined by immunohistochemistry in SS specimens from 12 patients (six each of biphasic and monophasic fibrous types). Immunohistochemical coexpression of HGF and c-Met was demonstrated in the epithelial component of five biphasic SS, while only c-Met was expressed in the epithelioid nests of three monophasic fibrous SS. The spindle cell component was negative for HGF and c-Met. In SS, positivity for epithelial markers, such as cytokeratins and epithelial membrane antigen, was diffusely observed in the epithelial component and was focally observed in spindle cells, while vimentin was positive predominantly in the spindle cell component. The areas expressing HGF and c-Met corresponded to distinct epithelial structures; however, HGF and c-Met expression were not found in any other tumor cells expressing epithelial markers in the spindle cell component of SS. Considering the morphogenic effect of HGF, which has been known to be one of its most important roles, the unique immunohistochemical localization of HGF and c-Met in SS suggests that the HGF/c-Met system may be closely related to the formation of epithelial (glandular) structures in biphasic SS.     

Solid dispersion particles of tolbutamide prepared with fine silica particles by the spray-drying method

Solid dispersion particles of tolbutamide (TBM) were prepared by formulating nonporous (Aerosil 200 (hydrophilic), Aerosil R972 (hydrophobic)) or porous (Sylysia 350 (hydrophilic), Sylophobic 200 (hydrophobic)) silica as a carrier and applying the spray-drying (SD) or evaporation (Eva) method. In the solid dispersion particles prepared by the SD method, TBM existed in a meta-stable form (Form II) irrespective of the type of silica. On the other hand, when the Eva method was used, various crystalline forms of TBM were observed in the solid dispersion particles according to the type of silica. Polymorphs of Forms III and IV were prepared with Aerosil 200 and Aerosil R972, respectively, while crystalline Form II was obtained when either of the forms of porous silica, Sylysia 350 or Sylophobic 200, was formulated. The dissolution property of TBM in the solid dispersion particles prepared with hydrophilic silica was remarkably improved compared with those of the original TBM crystals (Form I) or spray-dried TBM without silica (Form II). In the case of hydrophobic silica, the release rate of TBM from the solid dispersion particles was much slower than that of original TBM. The meta-stable form of TBM in the solid dispersion particles was stable for at least 4 weeks when stored at 60 °C and 0% RH, while the spray-dried TBM without silica (Form II) was gradually converted to the stable form (Form I) under the same storage conditions. Under the humid storage conditions (60 °C, 75% RH), the spray-dried TBM without silica (Form II) immediately converted into the stable form (Form I) within 1 day, while TBM (Form II) in the solid dispersions in a matrix of silica was stable for at least 1 week.     

Daily wheel running activity modifies the period of free-running rhythm in rats via intergeniculate leaflet

The period of free-running rhythms (tau) in rats, as measured using a running wheel, is different from that measured using an Automex. The aim of this work was to examine the effects of lesions of the intergeniculate leaflet (IGL) on the tau of these two activity rhythms. When blind rats were transferred from a cage with a running wheel to a cage without a running wheel, the tau lengthened. The tau of the wheel-running activity was associated with the number of wheel revolutions per day. A complete lesion of the IGL lengthened the tau of the wheel-running activity, and caused a reduction in the number of wheel revolutions per day in all rats. In rats housed in cages without a running wheel, locomotor activity was reduced by IGL lesions, although the tau was unaffected. When IGL-lesioned rats were transferred from a cage with a running wheel to a cage without a running wheel, no further change was observed. These results indicate that the tau is modified by the daily activity of wheel-running, but not by general locomotor activity, and that the IGL may be involved in this modification.