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(Objective) The aim of this study is to investigate the treatment outcome of laparoscopic radical prostatectomy (LRP). (Patients and methods) The study cohort consisted of 926 hormone-naïve patients with localized prostate cancer who underwent LRP at the Hiroshima Endourological Association from January 2007 to December 2016. (Results) The mean age was 69.4 years, the mean initial PSA was 9.1 ng/ml, and the mean follow-up period was 40.3 months. The D'Amico Risk Classification was Low: 232 cases, Intermediate: 344 cases, and High: 350 cases. Nerve preservation was performed bilaterally for 138 patients and unilaterally for 181 patients. The mean operative time was 181.0 minutes and the mean estimated blood loss was 360.7 ml. As the number of experienced cases increased, the operative time was significantly shorter and the estimated blood loss was significantly decreased. According to Clavien-Dindo classification, the ratio of perioperative complication degree IIIa or above was 4.0% (37 cases). The pathological results were Gleason score (GS) ≤6: 174 cases, GS7: 514 cases, GS ≥8: 232 cases, pT2≥: 704 cases, pT3a: 172 cases, pT3b: 47 cases, pT4: 3 cases, pN0: 917 cases, and pN1: 9 cases. Positive surgical margins were found in 278 cases (30.0%). The biochemical recurrence-free survival rate at 5 years was 78.1%. In multivariate analysis, age (≥70 yrs), initial PSA (≥10 ng/ml), biopsy GS (GS ≥8), cancer positive core ratio at biopsy (≥30%), pT (pT≥3), pathological GS (GS≥8), positive surgical margin and total number of patients in the facility were predictive factors of postoperative biochemical PSA recurrence. Younger age and nerve preservation were found to be predictive factors for the early recovery of urinary continence after surgery, with 88% regaining urinary continence at 12 months after surgery. (Conclusion) This study revealed the clinical outcome and appropriate candidates for LRP in Japanese patients.

OBJECTIVE We retrospectively compared the clinical outcomes of Lithoclast assisted lithotripsy (L group) with those of Holmium YAG laser assisted lithotripsy (H group). PATIENTS AND METHODS We analyzed records for operation time, duration of ureteral stenting, complication and stone-free rates in the L group (388 patients) and the H group (368 patients) for the primary procedure. RESULTS The stone locations (L group/H group) were U1 in 141/181, U2 in 69/57, and U3 in 178/130. Respective median stone sizes (L group/H group) were: U1,: 10.0/10.0 mm; U2,: 7.0/10.0 mm;, and U3,: 6.0/7.0 mm. Secondary procedures were performed in 79 L group patients and 35 H group patients. The median operation times (L group/H group) were 29.5/25.0 minutes. The median durations of ureteral stenting (L group/H group) were 4.0/4.0 days. The stone-free rates (L group/H group) according to the locations of the stones were 69.3/82.0% in U1, 85.5/87.0% in U2, and 92.0/98.4% in U3. Complications (L group/H group) were ureter perforation in 8/5 cases, pyelonephritis in 7/2 cases, ureteral stricture in 2/6 cases, and stone push up in 27/13 cases. CONCLUSION The operation time for holmium YAG laser assisted lithotripsy was significantly shorter than that of the Litoclast assisted procedure, and the stone-free rate with holmium YAG laser assisted lithotripsy was better than that with Lithoclast assisted lithotripsy for U1 and U3 stones.

Objectives: To assess the impact of baseline lower urinary tract symptoms on postoperative urinary morbidity in patients being treated for prostate cancer with 125-I permanent prostate brachytherapy. Methods: A total of 104 prostate cancer patients were enrolled in this study. Their urinary morbidity was followed up using the International Prostate Symptom Score and Expanded Prostate Cancer Index Composite for 12 months or more after permanent prostate brachytherapy. Patients were classified into two groups based on their baseline International Prostate Symptom Score: the low International Prostate Symptom Score group (score ≤ 7) and the high International Prostate Symptom Score group (score ≥ 8). Urinary morbidity was estimated in each group based on the results of the International Prostate Symptom Score and Expanded Prostate Cancer Index Composite measured before permanent prostate brachytherapy, and at 1, 3, 6, 9 and 12 months after the end of all radiation therapy. Results: The overall mean total International Prostate Symptom Score, International Prostate Symptom Score quality of life score, and urinary-related scores for Expanded Prostate Cancer Index Composite were significantly worse at 1 month after the end of treatment, but they improved gradually after the treatment and recovered to the baseline level within 12 months. Even in the high-International Prostate Symptom Score group, the International Prostate Symptom Score and International Prostate Symptom Score Quality of Life score were significantly worse at 1–3 months after permanent prostate brachytherapy, and then recovered to the baseline level without prolongation. Although the urination-related Expanded Prostate Cancer Index Composite score in the high-International Prostate Symptom Score group was significantly worse at 1 month after permanent prostate brachytherapy in comparison with that in the low-International Prostate Symptom Score group, it recovered to the baseline level without prolongation. Conclusions: The present findings suggest that the presence of lower urinary tract symptoms before implantation does not prolong urinary morbidity after permanent prostate brachytherapy.

The functions of melanin in the pigment cells, the ocellus and the otolith, of ascidian larvae were studied by their swimming behavior and cell morphology with and without 1-phenyl-2-thiourea (PTU), an inhibitor of vertebrate tyrosinase. Melanin formation in both the otolith and the ocellus of PTU-treated larvae at 12 hours of development was completely inhibited. These larvae were unable to swim because of abnormal tail development, but expression of rhodopsin in the outer segments of the photoreceptor was normal. In the PTU-treated larvae at 15 hours of development, melanin formation in the ocellus was inhibited, but that in the otolith seemed to be normal. The photic behavior of these larvae was normal, as was rhodopsin expression in the outer segments. However, the treated larvae lost upward swimming behavior. Synchrotron radiation X-ray fluorescence images showed that metallic elements of K, Ca, and Zn in the statocyte of larva were greatly decreased by PTU treatment, which may result in lowering the specific gravity of the pigment mass. SEM observations showed that the statocyte of Ciona intestinalis was supported by three parts, a foot-piece of the statocyte itself and two fibrous spring-like structures produced from protuberances. All three structures were synaptotagmin-positive. Movement of the statocyte would be detected by these three structures and thus would be responsible for the gravitational orientation. J. Comp. Neurol. 475:70–82, 2004. © 2004 Wiley-Liss, Inc.

The visual cycle system in a primitive chordate, ascidian Ciona intestinalis, was studied by whole-mount in situ hybridization and by whole-mount immunohistochemistry. Three visual cycle proteins, Ciona homologue of RGR (Ci-opsin3), CRALBP (Ci-CRALBP), and BCO/RPE65 (Ci-BCO/RPE65) were widely distributed in the brain vesicle and visceral ganglion. To identify the visual cycle system in a primitive chordate, we compared the localization of photoreceptor-specific proteins (visual pigment and arrestin) and visual cycle proteins (Ci-opsin3 and Ci-CRALBP). The ascidian visual cycle is composed of two cellular compartments, the photoreceptors and the brain vesicle, but some photoreceptor cells also contain visual cycle proteins.

BBF2H7 is an endoplasmic reticulum (ER)-resident transmembrane basic leucine zipper (bZIP) transcription factor that is cleaved at the transmembrane domain by regulated intramembrane proteolysis in response to ER stress. The cleaved cytoplasmic N-terminus containing transcription activation and bZIP domains translocates into the nucleus to promote the expression of target genes. In chondrocytes, the cleaved luminal C-terminus is extracellularly secreted and facilitates proliferation of neighboring cells through activation of Hedgehog signaling. In the present study, we found that Bbf2h7 expression levels significantly increased by 1.070-2.567-fold in several tumor types including glioblastoma compared with those in respective normal tissues, using the ONCOMINE Cancer Profiling Database. In some Hedgehog ligand-dependent cancer cell lines including glioblastoma U251MG cells, the BBF2H7 C-terminus was secreted from cells into the culture media and promoted cancer cell proliferation through activation of Hedgehog signaling. Knockdown of Bbf2h7 expression suppressed the proliferation of U251MG cells by downregulating Hedgehog signaling. The impaired cell proliferation and Hedgehog signaling were recovered by addition of BBF2H7 C-terminus to the culture medium of Bbf2h7-knockdown U251MG cells. These data suggest that the secreted luminal BBF2H7 C-terminus is involved in Hedgehog ligand-dependent cancer cell proliferation through activation of Hedgehog signaling. Thus, the BBF2H7 C-terminus may be a novel target for the development of anticancer drugs.

The need to reduce particles in semiconductor equipment and data storage equipment is in high demand. In recent years, barrier and glue layers on shields have been used to reduce particles generated in physical vapor deposition equipment. For this purpose, spray coatings are applied to shields. Although the sprayed metal films are exposed to vacuum in a vacuum chamber, their vacuum characteristics have seldom been investigated. The conventional spray coatings are usually done under atmospheric conditions. In order to obtain a layer that has a better vacuum characteristic, spray coating in a chamber filled with an inert gas was developed. Outgassing characteristics of sprayed aluminum films and titanium films were investigated by using the conductance modulation method. A sprayed metal film produced in an inert gas system showed a lower outgassing rate than that produced in an atmospheric condition.

This paper presents a prototype of a new concept of electromagnetic inductionbased fluid heating appliance using a voltage-source type series capacitorcompensated load-resonant high-frequency inverter using IGBT modules, which incorporates a phase-shifted pulse-width modulation (PWM) power regulation scheme. Proposed are also the load-resonant and quasi-resonant hybrid circuit topology of the voltage-fed soft-switching PWM inverter with inductive and capacitive hybrid lossless snubbers. In addition, some new types of electromagnetic induction heater to produce hot water, hot dry air and hightemperature superheated steam vapour are demonstrated. The feasible appliance employing the inverter mentioned above for electromagnetic induction-based liquid heating or gas heating is implemented from a practical point of view, along with the steady-state operating principle of this inverter system in addition to its remarkable features. The steady-state and dynamic-state operating characteristics of this high-freque...

At present, switching devices such as GCT (Gate Commutated Turn-off) thyristor and HVIGBT (High Voltage IGBT) are remarkably progressing and able to switch fast at high DC operation voltage above 2.5kV. However, a freewheeling diode which should realize the recovery performance similar to the turn-on performance of switching devices is not developed. In the high voltage diode, a main problem of the recovery performance is to prevent the voltage-oscillation. The voltage-oscillation brings miss-operation of driving circuit or voltage destruction of oneself. As the diode during the recovery operation can be regarded as a combination of one capacitance and two resistances, the oscillation mechanism was studied by replacing the diode to LCR circuit. As this results, it was clear that the diode during the recovery operation made surely the oscillation. On the basis of this analysis, the diode structure to mitigate oscillation was proposed.

Background Vascular endothelial growth factor-A (VEGFA) is the main mediator of angiogenesis. Angiogenesis plays important roles not only in many physiological processes, but also in the pathophysiology of many diseases. VEGFA is one of the therapeutic targets of treatment for ocular diseases with neovascularization. Therefore, elucidation of the regulatory mechanisms for VEGFA expression is important for the development of pharmaceutical drugs. Recent studies have demonstrated that the unfolded protein response is involved in the transcriptional regulation of VEGFA. However, the precise regulation of VEGFA in the human retina is not fully understood. Principal Findings When human retinal pigment epithelial cells, ARPE-19, were exposed to endoplasmic reticulum stressors, VEGFA mRNA was significantly upregulated. The unfolded protein response-related transcription factors XBP1, ATF4, ATF6, and OASIS were expressed in ARPE-19 cells. To determine which transcription factors preferentially contribute to the induction of VEGFA expression after endoplasmic reticulum stress, we carried out reporter assays using an approximately 6-kbp 5′-upstream region of the human VEGFA gene. Among these transcription factors, OASIS acted most effectively on the VEGFA promoter in ARPE-19 cells. Based on data obtained for certain deleted and mutated reporter constructs, we determined that OASIS promoted VEGFA expression by acting on a cyclic AMP-responsive element-like site located at around –500 bp relative to the VEGFA transcription start site. Furthermore, we confirmed that OASIS directly bound to the promoter region containing this site by chromatin immunoprecipitation assays. Conclusions and Significance We have demonstrated a novel regulatory mechanism for VEGFA transcription by OASIS in human retinal pigment epithelial cells. Chemical compounds that regulate the binding of OASIS to the promoter region of the VEGFA gene may have potential as therapeutic agents for ocular diseases with neovascularization.

To obtain large quantities of glutamic acid-specific protease isolated originally from Bacillus licheniformis (BLase), an expression plasmid was constructed by inserting the BLase gene into a plasmid vector (pUB110) for Bacillus subtilis . B. subtilis strain ISW1214 harboring the resultant recombinant plasmid containing the coding and 5′-promoter and 3′-terminator regions of BLase gene secreted approximately 0.25 g/ l of BLase in a culture medium contained in a 90- l jar fermentor, corresponding to nearly 10 times the natural production level and resulting in a stable large-scale production. The amount of BLase in the culture medium accounted for roughly 60% of the total extracellular proteins secreted from the recombinant strain, simplifying enzyme purification.

Improvement of a drug’s binding activity using the conformational restriction approach with sp3 hybridized carbon is becoming a key strategy in drug discovery. We applied this approach to BACE1 inhibitors and designed four stereoisomeric cyclopropane compounds in which the ethylene linker of a known amidine-type inhibitor 2 was replaced with chiral cyclopropane rings. The synthesis and biologic evaluation of these compounds revealed that the cis-(1S,2R) isomer 6 exhibited the most potent BACE1 inhibitory activity among them. X-ray structure analysis of the complex of 6 and BACE1 revealed that its unique binding mode is due to the apparent CH−π interaction between the rigid cyclopropane ring and the Tyr71 side chain. A derivatization study using 6 as a lead molecule led to the development of highly potent inhibitors in which the structure–activity relationship as well as the binding mode of the compounds clearly differ from those of known amidine-type inhibitors.

To assess the impact of baseline lower urinary tract symptoms on postoperative urinary morbidity in patients being treated for prostate cancer with 125-I permanent prostate brachytherapy.A total of 104 prostate cancer patients were enrolled in this study. Their urinary morbidity was followed up using the International Prostate Symptom Score and Expanded Prostate Cancer Index Composite for 12 months or more after permanent prostate brachytherapy. Patients were classified into two groups based on their baseline International Prostate Symptom Score: the low International Prostate Symptom Score group (score ≤ 7) and the high International Prostate Symptom Score group (score ≥ 8). Urinary morbidity was estimated in each group based on the results of the International Prostate Symptom Score and Expanded Prostate Cancer Index Composite measured before permanent prostate brachytherapy, and at 1, 3, 6, 9 and 12 months after the end of all radiation therapy.The overall mean total International Prostate Symptom Score, International Prostate Symptom Score quality of life score, and urinary-related scores for Expanded Prostate Cancer Index Composite were significantly worse at 1 month after the end of treatment, but they improved gradually after the treatment and recovered to the baseline level within 12 months. Even in the high-International Prostate Symptom Score group, the International Prostate Symptom Score and International Prostate Symptom Score Quality of Life score were significantly worse at 1-3 months after permanent prostate brachytherapy, and then recovered to the baseline level without prolongation. Although the urination-related Expanded Prostate Cancer Index Composite score in the high-International Prostate Symptom Score group was significantly worse at 1 month after permanent prostate brachytherapy in comparison with that in the low-International Prostate Symptom Score group, it recovered to the baseline level without prolongation.The present findings suggest that the presence of lower urinary tract symptoms before implantation does not prolong urinary morbidity after permanent prostate brachytherapy.

OASIS is a member of the CREB/ATF family of transcription factors and modulates cell- or tissue-specific unfolded protein response signalling. Here we show that this modulation has a critical role in the differentiation of neural precursor cells into astrocytes. Cerebral cortices of mice specifically deficient in OASIS (Oasis−/−) contain fewer astrocytes and more neural precursor cells than those of wild-type mice during embryonic development. Furthermore, astrocyte differentiation is delayed in primary cultured Oasis−/− neural precursor cells. The transcription factor Gcm1, which is necessary for astrocyte differentiation in Drosophila, is revealed to be a target of OASIS. Introduction of Gcm1 into Oasis−/− neural precursor cells improves the delayed differentiation of neural precursor cells into astrocytes by accelerating demethylation of the Gfap promoter. Gcm1 expression is temporally controlled by the unfolded protein response through interactions between OASIS family members during astrocyte differentiation. Taken together, our findings demonstrate a novel mechanism by which OASIS and its associated family members are modulated by the unfolded protein response to finely control astrocyte differentiation., This work was partly supported by grants from the Japan Society for the Promotion of Science KAKENHI (#22020030, #22800049), Sumitomo Foundation, Mochida Memorial Foundation for Medical and Pharmaceutical Research, Astellas Foundation for Research on Metabolic Disorders, Takeda Science Foundation, The Pharmacological Research Foundation Tokyo, Daiichi-Sankyo Foundation of Life Science, The Naito Foundation, Senri Life Science Foundation, Hokuto Foundation for Bioscience, and The Japan Prize Foundation.

Endoplasmic reticulum (ER) stress transducers transduce signals from the ER to the cytoplasm and nucleus when unfolded proteins accumulate in the ER. BBF2 human homolog on chromosome 7 (BBF2H7) and old astrocyte specifically induced substance (OASIS), ER-resident transmembrane proteins, have recently been identified as novel ER stress transducers that have roles in chondrogenesis and osteogenesis, respectively. However, the molecular mechanisms that regulate the activation of BBF2H7 and OASIS under ER stress conditions remain unresolved. Here, we showed that BBF2H7 and OASIS are notably unstable proteins that are easily degraded via the ubiquitin-proteasome pathway under normal conditions. ER stress conditions enhanced the stability of BBF2H7 and OASIS, and promoted transcription of their target genes. HMG-CoA reductase degradation 1 (HRD1), an ER-resident E3 ubiquitin ligase, ubiquitinated BBF2H7 and OASIS under normal conditions, whereas ER stress conditions dissociated the interaction between HRD1 and BBF2H7 or OASIS. The stabilization of OASIS in Hrd1(-/-) cells enhanced the expression of collagen fibers during osteoblast differentiation, whereas a knockdown of OASIS in Hrd1(-/-) cells suppressed the production of collagen fibers. These findings suggest that ER stress stabilizes OASIS family members and this is a novel molecular mechanism for the activation of ER stress transducers.

OASIS is a basic leucine zipper transmembrane transcription factor localized in the endoplasmic reticulum (ER) that is cleaved in its transmembrane region in response to ER stress. This novel ER stress transducer has been demonstrated to express in osteoblasts and astrocytes and promote terminal maturation of these cells. Additionally, OASIS is highly expressed in goblet cells of the large intestine. In this study, we investigated the roles of OASIS in goblet cell differentiation in the large intestine. To analyze the functions of OASIS in goblet cells, we examined morphological changes and the expression of goblet cell differentiation markers in the large intestine of Oasis(-/-) mice. By disrupting the Oasis gene, the number of goblet cells and production of mucus were decreased in the large intestine. Oasis(-/-) goblet cells showed abnormal morphology of mucous vesicles and rough ER. The expression levels of mature goblet cell markers were lower, and conversely those of early goblet cell markers were higher in Oasis(-/-) mice, indicating that differentiation from early to mature goblet cells is impaired in Oasis(-/-) mice. To determine the association of OASIS with other factors involved in goblet cell differentiation, in vitro experiments using a cell culture model were performed. We found that OASIS was activated in response to mild ER stress that is induced in differentiating goblet cells. Knockdown of the Oasis transcript perturbed goblet cell terminal differentiation. Together, our data indicate that OASIS plays crucial roles in promoting the differentiation of early goblet cells to mature goblet cells in the large intestine.

This report presents the outcome of prostate permanent brachytherapy (PPB). One hundred and seventy-two patients with clinically localized prostate cancer were treated with permanent brachytherapy using iodine-125 seeds (125-I) at Hiroshima University Hospital from July 2004 to June 2010. This study evaluated the efficacy of PPB in these patients. The median patient age was 69 years (range 53 to 82 years), the median prostate-specific antigen (PSA) value before biopsy was 6.75 ng/ml (range 3.5 to 47.9 ng/ml), and the median prostate volume was 23.1 ml (range 10.1 to 57 ml). The median follow-up was 37 months (range 1 to 72 months). The serum PSA levels decreased continuously after PPB throughout the entire follow-up period in 97% of patients without neoadjuvant hormonal therapy. No relapse occurred during the follow-up period in patients at low risk. Our 6-year experience suggests that PPB is effective for localized prostate cancer. Patients with prostate cancer that does not require combined external beam radiation therapy (EBRT) have the best chance of responding to treatment.

The effects of NO2 gas on textiles are investigated by using the JIS L 0855 method.In the present study, we have investigated the effects of NO2 gas on nylon BCF yarn for carpet when exposed to a fixed concentration of NO2 gas for several hours continuously.The results of this study showed noticeable color change caused by NO2 gas exposure, though the present JIS method showed no such change.Moreover, it was recognized that the effects of NO2 gas on dyed textiles vary according to dye structure.

At present the effects of NO2 gas on textile goods are investigated using the JIS L 0855 method.In the present study we have investigated the effects of NO2 on carpet nylon BCF yarns when exposed to a fixed concentration of NO2 for several hours continuously.The results of this study showed noticable color change caused by NO2 gas exposure in cases where the present JIS method showed no such change.Moreover, it was recognized that the effects of NO2 gas on dyed textile goods vary according to dye structure differences.

This paper presents a newly developed transformer-less single phase inverter for a photovoltaic (PV) power system. The proposed system consists of two sets of a PV array and buck-boost type chopper circuit. However, it is afraid that the system has lower "using rate" of PV energy than that of the ordinary PV system, as each PV array is only operated in the half duration of the AC power frequency. In this paper, it is also discussed how to increase this "using rate" by varying the connected capacitor between PV array terminals. The perturbation and observation method is adapted to the maximum power tracking in our PV systems. We adopt the wavelet transform to detect a power outage. The experimental data shows that this new inverter can supply AC power to the utility grid line with the power factor nearly unity.

The characterization of 1200 V trench IGBT using local lifetime control for clamped inductive load is fully investigated with the help of extensive measurements under various test conditions. The Trench IGBT improves some features of the planar IGBT: higher current density and lower on-state voltage drop. Higher current density resulting in a smaller cell size improves the conduction. However, it results also in an increase of the excess charges, which can reduce the switching performances. In this study, the use of a specific test circuit allows the collector current waveforms of the device under test to be obtained without any freewheeling diode reverse recovery influence. Extensive measurements show that the studied device presents high turn-on losses due to its high input capacitance responsible for the convex shape of the collector current waveform. However, the merits of the trench IGBT come from its lower on-state and also turn-off losses than the conventional planar device. The local lifetime control using proton irradiation is more efficient than the uniform lifetime control used in the third generation of planar devices to improve the trade-off between the on-state voltage drop and the turn-off losses.

This paper presents a perturbation and observation method with an identifier of capacitor for the maximum power point tracking (MPPT) in a photovoltaic power system. Usually, by increasing or decreasing the duty ratio of on-state of switching device, the maximum power point is tracked. The variation of duty ratio is determined by considering its circuit parameters. However, it is known that actual capacitance of an electrolytic capacitor in parallel with the photovoltaic array has 50% error of its nominal value. If the variation of duty ratio is determined based on its nominal value, the performance of MPPT is degraded. Thus, accordingly we must change the variation of duty ratio based on its actual value. In our system, we adapt the model reference adaptive system to identify the capacitor, then we can estimate the accurate capacitance and correct the variation of duty ratio. As a result, we may obtain the high performance of MPPT. Experimental results are shown using a proposed power inverter using buck-boost chopper circuits.

This paper presents a newly developed transformer-less single phase inverter for a photovoltaic (PV) power system. The proposed system consists of two sets of PV array and buck-boost type chopper circuit. However, the system has lower "using rate" of PV energy than that of the ordinary PV system, as each PV array is only operated in the half duration of the AC power frequency. In this paper, it is also discussed how to increase this "using rate" by varying the connected capacitor between PV array terminals. The simulation and experimental data show that the proposed inverter can supply the AC power to a utility grid line with the power factor nearly unity.

The surface of pure iron was glazed with a high-power CO2-gas laser to improve its surface hardness. The conditions of the CO2-gas laser were 1.6x105 W/cm2, continuous wave and multi mode at 5 kW. This laser beam was irradiated on the pure iron (99.9 wt%) surface under an Ar-gas (0.2 torr) atmosphere. The size of iron was 14x17x70 mm3. Microvickers hardness increased to 530 Hv (laser irradiated surface) from 257 Hv (substrate surface). The mechanism of increased hardness was analyzed with scanning electron microscopy and X-ray diffraction of the surfaces of both the laser irradiated and substrate iron. The SEM images showed that the laser glazed surface consisted of cross packed grains but the substrate surface included many micro pores. The hardened area had no boundary with its substrate and also had no cracks. From the results of XRD measurements, the patterns of the glazed surface partly changed to the amorphous phase and the relative intensity of (200) peak par (110) peak of δ-Fe changed to smaller than that of the substrate. These results suggested that the reasons for the increased hardness of the laser glazed surface were the disappearance of micro pores and the appearance of fine grains and amorphous phase.The surface of pure iron was glazed with a high-power CO2-gas laser to improve its surface hardness. The conditions of the CO2-gas laser were 1.6x105 W/cm2, continuous wave and multi mode at 5 kW. This laser beam was irradiated on the pure iron (99.9 wt%) surface under an Ar-gas (0.2 torr) atmosphere. The size of iron was 14x17x70 mm3. Microvickers hardness increased to 530 Hv (laser irradiated surface) from 257 Hv (substrate surface). The mechanism of increased hardness was analyzed with scanning electron microscopy and X-ray diffraction of the surfaces of both the laser irradiated and substrate iron. The SEM images showed that the laser glazed surface consisted of cross packed grains but the substrate surface included many micro pores. The hardened area had no boundary with its substrate and also had no cracks. From the results of XRD measurements, the patterns of the glazed surface partly changed to the amorphous phase and the relative intensity of (200) peak par (110) peak of δ-Fe changed to smaller t...

Glucagon was expressed in Escherichia coli as a fusion protein including the glucagon sequence [Ishizaki et al. (1992), Appl. Microbiol. Biotechnol. 36, 483-486]. The high-level expression of a protein in E. coli often results in an insoluble aggregate called an inclusion body containing a fusion protein. In our previous report [Yoshikawa et al. (1992), J. Protein Chem. 11, 517-525], we solubilized this inclusion body by using guanidinium chloride. However, the existence of denaturant caused problems such as a low proteolytic activity for transforming the fusion protein into glucagon and complicated purification methods. We tried to improve the method to enable large-scale purification. At alkaline pH, the inclusion body could be solubilized to a high concentration and cleaved by amino acid-specific endopeptidases. By utilizing isoelectric precipitations as a new economical purification method for glucagon from intermediates, the glucagon obtained was shown to be over 99.5% pure by analytical RP-HPLC. The yield was almost equal that of our previous method, and the glucagon produced was chemically and biochemically equivalent to natural glucagon.

Twenty strains of Staphylococcus aureus from ATCC type cultures and strains found in clinical studies were cultivated, and their endopeptidase activity specific for glutamic acid was surveyed using benzyloxycarbonyl-Phe-Leu-Glu-p-nitroanilide (Z-Phe-Leu-Glu-pNA) as a substrate. The activity was found in two of the strains, ATCC 12600 and ATCC 25923. A glutamic acid-specific proteinase, which we propose to call SPase, was purified from the culture filtrate of S. aureus strain ATCC 12600 by a series of column chromatographies on DEAE-Sepharose twice and on Sephacryl S-200. A single band was observed on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of the purified SPase. The molecular weight of the proteinase was estimated to be 34000 by SDS-PAGE. When synthetic peptides and oxidized insulin B-chain were used as substrates, SPase showed the same substrate specificity as V8 proteinase, EC 3.4.21.9, which specifically cleaves peptide bonds on the C-terminal side of glutamic acid and aspartic acid. Examination with p-nitroanilides of glutamic acid and aspartic acid as substrates, however, revealed that both proteinases are highly specific for a glutamyl bond in comparison with an aspartyl bond. To elucidate the complete primary structure of SPase, its gene was cloned from genomic DNA of S. aureus ATCC 12600, and the nucleotide sequence was determined. Taking the amino acid sequence of SPase from the NH2-terminus to the 27th residue into consideration, the clones encode a mature peptide of 289 amino acids, which follows a prepropeptide of 68 residues. SPase was confirmed to be a novel endopeptidase specific for glutamic acid, being different from V8 proteinase which consists of 268 amino acids.

Fast- switching reverse-conducting thyristors have been developed and used in dc chopper apparatus to control the speed of highvoltage dc traction motors. The newly developed dc chopper circuit and its application for low-voltage dc motor control are discussed. The fast-switching reverse-conducting thyristor is utilized as the main thyristor to control load current.

A new 100A, 500V n-channel enhancement mode power MOSFET module is introduced in this paper. In the introduction an overview on the existing devices has been given. The nunerous merits of the new device are illustrated by means of various static and dynamic characteristics. The classic problem of intrinsic bipolar action, which leads to destruction of power MOSFET have been discussed. The new device has shown a very high level of ruggednes against di/dt, dv/dt stress besides low on-resistance, fast switching speed and other superior characteristics.

A high power CO2 laser at the maximum power of 5 kW of multi-mode beam was irradiated on to mild steel and carbon graphite targets, positioned typically 10 mm below the focus point, both in air and argon, and at pressure ranging from 2 to 101 kPa. Spectra from plume were measured by a spectrometer. Temperatures of atoms were calculated from their spectra, assuming a local thermal equilibrium conditions of the plume.For the mild steel plume, spectral lines due to excitation of atoms were obtained and the temperatures was calculated as at 3000 K. On the other hand, spectral lines due to C2 molecules were observed for carbon plume. The vibrational temperature of C2 was analyzed corresponded with the rotational temperature. The temperatures of the carbon plumes was evaluated in a range from 4000 to 6000K depending on experimental conditions such as laser power and ambient pressure.A high power CO2 laser at the maximum power of 5 kW of multi-mode beam was irradiated on to mild steel and carbon graphite targets, positioned typically 10 mm below the focus point, both in air and argon, and at pressure ranging from 2 to 101 kPa. Spectra from plume were measured by a spectrometer. Temperatures of atoms were calculated from their spectra, assuming a local thermal equilibrium conditions of the plume.For the mild steel plume, spectral lines due to excitation of atoms were obtained and the temperatures was calculated as at 3000 K. On the other hand, spectral lines due to C2 molecules were observed for carbon plume. The vibrational temperature of C2 was analyzed corresponded with the rotational temperature. The temperatures of the carbon plumes was evaluated in a range from 4000 to 6000K depending on experimental conditions such as laser power and ambient pressure.

High power laser irradiation on materials induces a plasma plume whose electrical characteristics have not been fully understood because of its instabilities. We have measured the transient electric charge signal from a laser plasma plume by means of a high sensitivity electric charge detector which were detectable pulse-like electric charge signals having a rise time of less than 1 μsec. The laser plasma was formed on a mild steel (Fe 98.9%) surface by a CO2-laser in a vacuum at pressure of 13.3 Pa. The power of the CO2-laser ranged from 1 to 5 kW and the specimen was moved at a speed of 10 mm/sec. The collected electric charge signals decreased as the laser irradiation power increased. In contrast, the intensity of light signals from the plume and irradiated surface increased with the increase of the laser power. We discuss a possible reason for the observed behavior of transient electric charge signals and light intensity signals in relation to the phenomena that occurs in the plasma plume, as well as its relationship to the optimum condition for laser hardening.High power laser irradiation on materials induces a plasma plume whose electrical characteristics have not been fully understood because of its instabilities. We have measured the transient electric charge signal from a laser plasma plume by means of a high sensitivity electric charge detector which were detectable pulse-like electric charge signals having a rise time of less than 1 μsec. The laser plasma was formed on a mild steel (Fe 98.9%) surface by a CO2-laser in a vacuum at pressure of 13.3 Pa. The power of the CO2-laser ranged from 1 to 5 kW and the specimen was moved at a speed of 10 mm/sec. The collected electric charge signals decreased as the laser irradiation power increased. In contrast, the intensity of light signals from the plume and irradiated surface increased with the increase of the laser power. We discuss a possible reason for the observed behavior of transient electric charge signals and light intensity signals in relation to the phenomena that occurs in the plasma plume, as well as ...

This paper describes numerical analysis of transient heat transfer in a metal specimen during high-power laser irradiation. Three-dimensional finite element models of the heat flow are developed and solved, where both the convection and the radiation effects from the surfaces and the temperature dependence of all thermo-physical properties are taken into account. In this calculation, properties of iron (SS400) are used. Continuous (CW) laser irradiation of which maximum heat input 320 W, corresponding to 4 kW laser power, is applied to metal with stationary and a constant moving velocity conditions. The laser beam shapes are assumed circular or elliptical. We investigate the effects of heat input on the temperature distribution and its response based upon the model. As a result of the simulation, the heat-conduction effects are the most significant factor affecting the heat transfer processes, but the convection and radiation effects from the surface are negligible under the present conditions. Only a very thin layer (less than 0.5 mm) near the surface heated by the heat input can be high temperature regions. Simulated temperature responses along the central axis are compared with experimental results of temperature distribution obtained by a two-dimensional infrared thermometer, and both results are in good agreement, which indicated the validity of the present models. The maximum cooling rate can be estimated in the heated region, where the cooling rates is typically 103 - 104 °C/s, linearly depending on the heat input. Experimental results of laser hardening on the iron (SS400) specimen are compared with the cooling rate of these simulated results. The dependency of the hardening on the cooling rate is obtained.This paper describes numerical analysis of transient heat transfer in a metal specimen during high-power laser irradiation. Three-dimensional finite element models of the heat flow are developed and solved, where both the convection and the radiation effects from the surfaces and the temperature dependence of all thermo-physical properties are taken into account. In this calculation, properties of iron (SS400) are used. Continuous (CW) laser irradiation of which maximum heat input 320 W, corresponding to 4 kW laser power, is applied to metal with stationary and a constant moving velocity conditions. The laser beam shapes are assumed circular or elliptical. We investigate the effects of heat input on the temperature distribution and its response based upon the model. As a result of the simulation, the heat-conduction effects are the most significant factor affecting the heat transfer processes, but the convection and radiation effects from the surface are negligible under the present conditions. Only a ver...