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Neuropeptide Y (NPY) Y5 receptor plays a key role in the effects of NPY, an important neurotransmitter in the control of energy homeostasis including stimulation of food intake and inhibition of energy expenditure. The NPY-Y5 receptor system has been an attractive drug target for potential use in treating obesity. Here we report the discovery and characterization of two novel Y5 receptor antagonists, S-2367 and S-234462. Both compounds displayed high affinity for the Y5 receptor in the radio-ligand binding assay, while in the cell-based functional assay, S-2367 and S-234462 showed, respectively, surmountable and insurmountable antagonism. In cell-based washout experiments, S-234462 dissociated from the Y5 receptor more slowly than S-2367. In vivo study showed that S-234462 effectively suppressed food intake induced by acute central injection of a selective Y5 receptor agonist. Furthermore, high-fat diet-induced obese (DIO) mice treated with S-234462 for 5 weeks showed a significant decrease in body weight gain and food intake compared to those treated with S-2367. In conclusion, S-234462 exhibits insurmountable antagonism of NPY Y5 receptor in vitro and superior anti-obesity effects to the surmountable NPY Y5 antagonist S-2367 in DIO mice.

Microreactors with gas–liquid slug flow have an advantage over the conventional batch reactors in mass transfer between mutually immiscible fluids because of the internal circulation flow within the liquid slug. To realize stable long-term operation of microreactors with gas–liquid slug flow, the slug lengths in the microreactors have to be monitored and controlled, because they influence mass transfer performance. In this study, an experimental investigation is carried out to analyze the formation of gas–liquid slug flow in a T-shaped microreactor. The experimental result shows that the pressures in gas and liquid feeding tubes connected to the microreactor oscillate periodically along the formation of a pair of gas and liquid slugs. Based on this result, a method for estimating slug lengths from feed pressure measurements is developed. The method is non-invasive and does not affect slug formation or the manner of gas–liquid slug flow. Its effectiveness was assessed through experimental case studies using T-shaped microreactors having different gas–liquid confluence angles and different gas and liquid flow rates. The relative root mean square errors of estimated slug lengths were within 2% for one minute operation. The results clearly show that the proposed method can be applied to the real time monitoring of slug lengths.

Rapid conduction of nerve impulses is critical in life and relies on action potential (AP) leaps through the nodes of Ranvier (NRs) along myelinated nerves. While NRs are the only sites where APs can be regenerated during nerve conduction on myelinated nerves, ion channel mechanisms underlying the regeneration and conduction of APs at mammalian NRs remain incompletely understood. Here, we show that TREK-1 and TRAAK, the thermosensitive and mechanosensitive two-pore-domain potassium (K2P) channels, are clustered at NRs of rat trigeminal Aβ-afferent nerves with a density over 3,000-fold higher than that on their somas. These K2P channels, but not voltage-gated K+ channels as in other parts of nerves, are required for rapid AP repolarization at the NRs. Furthermore, these channels permit high-speed and high-frequency AP conduction along the myelinated afferent nerves, and loss of function of these channels at NRs retards nerve conduction and impairs sensory behavioral responses in animals.

Recent efforts have been made to identify useful urinary biomarkers of nephrotoxicity. Furthermore, the application of urine to the other toxicities as new biomarker source has been recently expanded. Meanwhile, correction of urinary biomarker concentrations according to fluctuations in urine flow rate is required for adequate interpretation of the alteration. The urinary biomarker-to-creatinine ratio (UBCR) is widely used because of the convenience, while the urinary biomarker-excretion rate is regarded as the gold standard corrective method. Because creatinine is a catabolite in energy production in muscles, we hypothesized that altered muscle mass could affect creatinine kinetics, ultimately affecting UBCR. However, no study has examined this hypothesis. In this study, we examined the influence of muscle mass gain on UBCR, using male Sprague-Dawley rats during the growth phase, 6–12-week old. Both plasma creatinine and excretion of urinary creatinine (Ucr excretion) showed increases with muscle mass gain in rats, in which the alterations of UBCR were lowered. The renal mRNA level of the organic cation transporter-2 (Oct2), a creatinine transporter, showed an age-related increase, whereas the mRNA level of multidrug and toxin extrusions-1 (Mate1) remained constant. Multiple regression analysis showed that the increase in creatinine clearance highly contributed to the age-related increase in Ucr excretion compared to the mRNA levels of Oct2 and Mate1. This suggested that the age-related increase in Ucr excretion may be attributable to the increased transglomerular passage of creatinine. In conclusion, the results suggest that muscle mass gain can affect creatinine kinetics, leading to underestimation of UBCR. Therefore, it is important to understand the characteristics of the corrective method when using urinary biomarker, the failure of which can result in an incorrect diagnosis.

This paper reports the recent results of improving the radiation hardness of silicon solar cells, which is SHARP and NASDA's project since 1998 (Tonomura et al., Second World Conference on Photovoltaic Solar Energy, 1998, pp. 3511–3514). Newly developed 2×2 cm2 Si solar cells with ultrathin substrates and both-side junction (BJ) structure showed 72.0 mW (13.3% efficiency) maximum output power at AM0, 28°C after 1 MeV electron irradiation up to 1×1015 e/cm2 and the best cell showed 72.5 mW (13.4%) maximum output power. These solar cells have p–n junctions at both front and rear surfaces and showed less radiation degradation and better remaining factor than previous solar cells.

Cardiotoxicity and musculoskeletal toxicity can be life-threatening, and thus have strong impact on both the development and marketing of drugs. Because the conventional biomarkers such as aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and creatine kinase (CK) have low detection power, there has been increasing interest in developing biomarkers with higher detection power. The current study examined the usefulness of several promising biomarkers, cardiac and skeletal muscle troponins (cTnI, cTnT and sTnI), fatty acid binding protein 3 (FABP3) and myosin light chain 3 (MYL3), and compared the obtained data to AST, LDH and CK in rat models treated with various myotoxic and non-myotoxic compounds (isoproterenol, metaproterenol, doxorubicin, mitoxantrone, allylamine, cyclosporine A, cyclophosphamide, aminoglutethimide, acetaminophen, methapyrilene, allylalcohol and α-naphthylisothiocyanate). These promising biomarkers were found to be superior to the conventional biomarkers, as they had a specific and abundant distribution within the heart and/or skeletal muscles; exhibited a positive correlation between the amplitude of increases and the degree of pathological alterations; had higher diagnostic accuracy for detecting pathological alterations; and had the additive effect of improving the diagnostic accuracy of conventional biomarkers. However, these promising biomarkers have several drawbacks including a rapid clearance, the fact that they are affected by renal dysfunction, and different reactivity to the mode of action of individual myotoxicants. In conclusion, the promising biomarkers cTnI, cTnT, FABP3, MYL3, and sTnI demonstrated sensitivity and specificity for cardiac and skeletal myotoxicity that was superior to those of conventional biomarkers, while we should pay attention to the drawbacks of these biomarkers when used in toxicity studies.

Among 13 kinds of metal oxides, ceria (CeO 2 ) shows the highest catalytic activity for one-pot selective synthesis of the secondary amide from 2-cyanopyridine and n -octylamine as a test reaction. CeO 2 acts as a reusable heterogeneous catalyst, and it is effective for the secondary amide formation from various nitriles and amines in high yields (73% to >99%). Pharmacologically important products such as heteroaromatic N-alky amides and morpholine amide are effectively synthesized, indicating that CeO 2 can be a practically useful catalyst. A proposed mechanism includes (1) hydration of nitrile to the primary amide and (2) transamidation of the primary amide with amine as the rate-limiting step. This reaction mechanism provides a reason why the present catalytic system gives high selectivity.

Recent research has revealed several useful urinary biomarkers of renal dysfunction such as acute kidney injury (AKI). For adequate evaluation of altered urinary biomarkers, it is necessary to consider the influence of varied urine flow rate (UFR). Calculation of the excretion rate of a urinary biomarker (UFR-correction) is the gold standard for the correction of UFR variation. An alternative method that is widely used is to calculate the ratio of the biomarker level to urinary creatinine (Ucr-correction). To date, the equivalence between these two methods has been examined only in a steady state situation such as diabetic nephropathy, and the urinary biomarkers examined have been limited to proteinuria and albuminuria. Therefore, we comprehensively addressed the relationship between Ucr-correction and UFR-correction of ten urinary biomarkers N-acetyl-β-d-glucosaminidase (NAG), lactate dehydrogenase (LDH), total protein, albumin, kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, clusterin, β(2)-microglobulin, cystatin-c and glutathione S-transferase-α in non-steady state situations such as AKI. All ten urinary biomarkers showed larger amplitude increases in AKI by Ucr-correction than by UFR-correction in linear regression analysis. Moreover, receiver operating characteristic curves analysis suggested that, at least for the biomarkers NAG and LDH, Ucr-correction had higher diagnostic power than UFR-correction. We observed a decrease in the Ucr excretion in AKI that was accompanied by a reduction in creatinine clearance and reduced mRNA expression of the renal organic cation transporter-2, which is known to function as a transporter for creatinine. These results may provide a mechanistic explanation for the phenomena obtained in Ucr-correction. In conclusion, while Ucr-correction could overestimate the degree of AKI, it could also provide higher diagnostic power for AKI than UFR-correction. We should take into consideration of these backgrounds when using the Ucr-correction.

Cardiotoxicity represents one of the most serious side effects of new drugs. It is essential for pharmaceutical companies to detect potential cardiotoxicity of candidate drugs in non-clinical studies during the early stages of drug development. In this study, we aimed to detect potential genomic biomarkers of rat cardiotoxicity using a toxicogenomics approach. In order to achieve this, we induced cardiac lesions in rats following treatment with the three prototypical cardiotoxic compounds isoproterenol, doxorubicin and carbofuran. We then undertook histopathological examination and microarray analysis at 8 or 24 h after single dosing. Using statistical and cluster analysis, we extracted 36 probe sets commonly up-regulated by the three cardiotoxic compounds. GO analysis revealed that these genes were functionally associated with either chemotaxis, tissue regeneration, positive regulation of cell proliferation, cellular organization and morphogenesis events in accordance with the degeneration of myocardium and inflammation observed in the histopathology analysis. Most of selected genes showed transient up-regulation at different time point for each compound. However, among these genes, Spp1, Fhl1, Timp1, Ccl7 and Reg3b revealed a sustained up-regulation with high expression levels at both time points for all three compounds. In conclusion, even though definitive validation studies are required for the establishment of their usefulness and reliability, these identified genes may prove to be the most promising candidate genomic biomarkers of cardiotoxicity in rats.

The purpose of this study was to investigate the influence of hydrostatic pressure (HP) on the gene expression of cartilage matrix, cytokines, and apoptosis-associated factors in chondrocytes in which the cartilage was in extracellular matrix (ECM)-rich or ECM-poor condition.Chondrocytes were isolated from rabbit joints and cultured in alginate beads. Immediately after embedding (0W group) or after 2 weeks culture (2W group), the amounts of glycosaminoglycan (GAG) in the alginate beads were quantified. Both groups were exposed to continuous HP of 10 or 50 MPa for 12 h. The expression of inflammatory cytokines, proteases, and apoptosis-related factors were examined by reverse transcription-polymerase chain reaction (RT-PCR). The expression of proteoglycan core protein (PG) and collagen type II were quantified by real-time RT-PCR.All of the GAG components in alginate beads markedly increased in the 2W group. The expression of PG and collagen type II increased after exposure to 10 MPa in both groups. In the 0W group, these levels decreased after exposure to 50 MPa of HP. The expression of interleukins IL-6 and IL-8 increased after exposure to HP in the 0W group. HP at 50 MPa induced mRNA expression of ADAMTS-5 in the 0W group but not in the 2W group. The expression of Fas increased after exposure to HP in the 0W group.These findings suggested that nonphysiological, excessive HP on chondrocytes with the ECM in poor condition reduced matrix gene expression and increased expression of the genes associated with apoptosis and catabolism of the cartilage matrix. These results might therefore be associated with the pathogenesis of osteoarthritis.

The aim of this study was to clarify the significance of subchondral bone in the pathology of osteoarthritis (OA) by investigating the expression of inflammatory cytokines, proteases, and receptor activator of NF-kappaB ligand (RANKL)/receptor activator of NF-kappaB (RANK)/osteoprotegerin (OPG) involved in cartilage degeneration.Subchondral bone was obtained from 19 patients diagnosed with knee OA and 4 patients diagnosed with femoral neck fracture. Subchondral bone osteoblasts (SBOs) were isolated, and total RNA was extracted. Messenger RNA expression of inflammatory cytokines, proteases, and RANKL/RANK/OPG were analyzed using a real-time reverse transcription-polymerase chain reaction (RT-PCR).Real-time RT-PCR showed that mRNA expressions of interleukin-6 (IL-6), matrix metalloproteinase-13 (MMP-13), and RANKL were significantly enhanced in OA SBOs compared to SBOs without OA. The expressions of these genes was greater in patients with severe cartilage damage than in those with mild cartilage damage. A high correlation between mRNA expression of IL-6 and that of MMP-13 was found in OA SBOs.The increases in IL-6, MMP-13, and RANKL expression in OA SBOs suggest that in subchondral bone OA progression involves abnormal osseous tissue remodeling, which induces mechanical property changes. Cartilage degeneration in OA may also be due, at least in part, to IL-6 and MMP-13 produced by SBOs. Comprehensive research on these pathological features may lead to the development of more effective therapies for OA by administration of molecules that affect bone remodeling and metabolism.

Numerous studies have demonstrated the effect of shear stress on osteoblasts, but its effect on odontogenic cells has never been reported. In this study, we focused on the effect of shear stress on facilitating tissue-engineered odontogenesis by dissociated single cells. Cells were harvested from the porcine third molar tooth at the early stage of crown formation, and the isolated heterogeneous cells were seeded on a biodegradable polyglycolic acid fiber mesh. Then, cell-polymer constructs with and without exposure to shear stress were evaluated by in vitro and in vivo studies. In in vitro studies, the expression of both epithelial and mesenchymal odontogenic-related mRNAs was significantly enhanced by shear stress for 2 h. At 12 h after exposure to shear stress, the expression of amelogenin, bone sialoprotein and vimentin protein was significantly enhanced compared with that of control. Moreover, after 7 days, alkaline phosphatase activity exhibited a significant increase without any significant effect on cell proliferation in vitro. In vivo, enamel and dentin tissues formed after 15 weeks of in vivo implantation in constructs exposure to in vitro shear stress for 12 h. Such was not the case in controls. We concluded that shear stress facilitates odontogenic cell differentiation in vitro as well as the process of tooth tissue engineering in vivo.

Objective Although the perioperative use of immune-enhancing enteral formula (IEEF) effectively reduces the rate of infectious complications, whether chronic use of IEEF is beneficial is unknown. A prospective randomized clinical trial was performed to examine the safety and effectiveness of long-term IEEF on nutritional and immunologic status in non-surgical patients receiving total enteral nutrition through the gastrostomy access route. Methods A total of 30 patients were randomly assigned to two groups in which they received total enteral nutrition, an IEEF (n = 15) or a regular polymeric enteral formula (control group; n = 15) for 12 wk. Nutritional and immunologic variables were periodically examined. Results Serum concentrations of insulin-like growth factor-I increased significantly for the IEEF group throughout the study. Although serum concentrations of dihomo-γ-linoleic acid decreased significantly in the IEEF group, serum concentrations of eicosapentaenoic acid and docosahexaenoic acid increased significantly, as did concentrations of serum arginine and ornithine. The CD4/CD8 ratio and natural killer cell activity also increased for the IEEF group, but the differences were not significant. The B-cell fraction increased and the T-cell fraction of peripheral lymphocytes decreased for the IEEF group. Neither infectious nor non-infectious complications occurred during the study period in either group, except for a significant increase in serum urea nitrogen and uric acid concentrations for the IEEF group. Conclusion Long-term use of IEEF is safe in non-surgical patients and results in a significant increase in serum insulin-like growth factor-I concentrations in association with increased humoral immunity.

Summary Objective To investigate the effect of l-glutamine (Gln) on stress responses of chondrocytes exposed to heat stress or nitric oxide (NO). Methods Cultures of articular chondrocytes were established from rabbit joints, and treated for 12h with various concentrations of Gln (0–20mM). In some experiments, cells were also treated with quercetin (Que), a heat shock protein 70 (HSP70) inhibitor. Heat stress (43°C) was applied to the cells for 0–120min. Apoptosis was induced by 0.5mM sodium nitroprusside (SNP) dihydrate that produces NO. After stress loading, HSP70 expression was detected by Western blot analysis. Cell viability was assessed by lactate dehydrogenase (LDH) release and tetrazolium salt-based assays, while apoptosis was evaluated by Hoechst 33342 staining, TUNEL methods and active caspase-3 determination. Results Gln demonstrated dose-dependent enhancing effect on stress-mediated induction of HSP70, while in the absence of any stress HSP70 was not induced by Gln alone. After heating or SNP loading, chondrocytes showed severe reduction in viability, while the cytotoxic outcome was almost completely abrogated by conditioning with Gln. The protective effect of Gln was significantly blocked by Que that effectively suppressed stress-induced HSP70 expression in chondrocytes. The Gln also rendered chondrocytes unsusceptible to NO-induced apoptosis that was frequently seen in SNP-treated culture. Conclusion This study demonstrated that the treatment of chondrocytes with Gln protected the cells from heat stress and NO-induced apoptosis. These chondroprotective effects of Gln may be mediated by HSP70.

The yeast Torulaspora pretoriensis YK-1 possesses both high potential leavening ability and freeze-thaw resistance, but its leavening ability in dough, without the addition of sugar, is much less than commercial baking strains (Oda and Tonomura 1993) Institute for Fermentation, Osaka, Japan (IFO) 0022, another strain of T. pretoriensis, previously found to leaven dough efficiently without the addition of sugar, showed higher activities of both maltose permease and α-glucosidase and fermented maltose in an aqueous medium faster than YK-1. No significant difference was observed between the affinities of maltose permease and α-glucosidase from IFO 0022 and those from YK-1. MAL61 and MAL62 genes of Saccharomyces cerevisiae were expressed in T. pretoriensis YK-1 and elevated the activities of maltose permease and α-glucosidase, respectively, when these genes were introduced on YCp-type plasmids under control of the glyceraldehyde 3-phosphate dehydrogenase promoter. Maltose fermentation by cells harbouring the plasmids carrying either MAL61 or MAL62 genes was slightly stimulated. Introduction of both genes further enhanced the maltose fermentation rate but not leavening ability in dough without the addition of sugar. These results suggest that maltose permease and α-glucosidase determine the overall velocity of maltose fermentation.

We investigated vortex dynamics in the ratchet system in a Niobium superconductor by using a direct imaging technique of Lorentz microscopy. We directly observed one-directional selective motion in fabricated channels, which resulted from the rectification of vortices in a spatially asymmetric potential under the oscillating magnetic field in a temporally symmetric manner. Based on observation of the individual motion of vortices, elementary process involved in this rectification was clarified.

This study was undertaken to evaluate and reduce the allergenicity of crustacean extractives that are added to a variety of processed foods as seasonings. Tropomyosin, the major crustacean allergen, was detected in only one of the six kinds of crustacean extractives by SDS–PAGE and immunoblotting. However, all the extractives were shown to be considerably allergenic by inhibition ELISA using sera from crustacean-allergic patients. Analyses by gel filtration HPLC suggested that tropomyosin is mostly degraded to peptide fragments during manufacturing of the extractives but at least some of the fragments are still IgE-reactive. On digestion with proteases, the allergenicity of the extractives was almost completely lost. The effectiveness of protease digestion to reduce the allergenicity of tropomyosin was also confirmed in model experiments using the heated extracts from four species of crustaceans.

Three new compounds, orirubenone A (1), B (2) and C (3) were isolated from the mushroom Tricholoma orirubens. Their structures were determined by spectral analyses. These compounds inhibited hyaluronan-degradation by human skin fibroblasts.

Three Trp variants of lysyl-tRNA synthetase from Bacillus stearothermophilus, in which either one or both of the two Trp residues within the enzyme (Trp314 and Trp332) were substituted by a Phe residue, were produced by site-directed mutagenesis without appreciable loss of catalytic activity. The following two phenomena were observed with W332F and with the wild-type enzyme, but not with W314F: (1) the addition of L-lysine alone decreased the protein fluorescence of the enzyme, but the addition of ATP alone did not; (2) the subsequent addition of ATP after the addition of excess L-lysine restored the fluorescence to its original level. Fluorometry under various conditions and UV-absorption spectroscopy revealed that Trp314, which was about 20A away from the lysine binding site and was shielded in a non-polar environment, was solely responsible for the fluorescence changes of the enzyme in the L-lysine activation reaction. Furthermore, the microenvironmental conditions around the residue were made more polar upon the binding of L-lysine, though its contact with the solvent was still restricted. It was suggested that Trp314 was located in a less polar environment than was Trp332, after comparison of the wavelengths at the peaks of fluorescence emission and of the relative fluorescence quantum yields. Trp332 was thought, based on the fluorescence quenching by some perturbants and the chemical modification with N-bromosuccinimide, to be on the surface of the enzyme, whereas Trp314 was buried inside. The UV absorption difference spectra induced by the L-lysine binding indicated that the state of Trp314, including its electrostatic environment, changed during the process, but Trp332 did not change. The increased fluorescence from Trp314 at acidic pH compared with that at neutral pH suggests that carboxylate(s) are in close proximity to the Trp314 residue.

SrS:Ce films were investigated by secondary ion mass spectrometry (SIMS) in order to examine the luminescent center distribution in the phosphor before and after annealing. Cerium was accumulated near the interfaces between the phosphor and insulating layers, and this accumulation was most extensive in the phosphor annealed in H2S. The Ce accumulation is found to shift the electroluminescent (EL) emission spectra to a longer wavelength. It is also found that crystallinity improvement of the SrS phosphor by annealing in H2S causes Ce accumulation and the presence of oxygen enhances the Ce accumulation.

The in-air high-resolution PIXE system composed of a flat analyzing crystal and a position-sensitive proportional counter was applied to measure line shifts of Si Kα and P Kα X-rays from various samples induced by an external proton beam. Line shifts that reflect chemical environments of atoms in target samples were determined with the precision of 0.1 eV. The utility of the method for chemical state analysis of minor elements down to the order of 0.1% was demonstrated.

Thermolysin, a thermophilic metalloproteinase, is markedly activated in the presence of high concentrations (1–5 M) of neutral salts. The activity increases in an exponential fashion with increasing salt concentration, and is enhanced 13–15 times with 4 M NaCl at pH 7.0 and 25°C (K. Inouye, Effects of salts on thermolysin: activation of hydrolysis and synthesis of N -carbobenzoxy- l -aspartyl- l -phenylalanine methyl ester, and a unique change in the absorption spectrum of thermolysin, J. Biochem. 112 (1992) 335–340). In this study, the effect of NaCl on the thermal stability of thermolysin has been examined at 60–85°C. The activation energy, E a , for the thermal inactivation is 15 kcal/mol at 0 M NaCl, and increases up to 30–33 kcal/mol by the addition of 0.5–1.5 M NaCl. Further increase in [NaCl] decreases the E a value, and at 4 M NaCl it is almost the same as that at 0 M NaCl. Thermolysin at 0.5–1.5 M NaCl is twice as heat-stable as in the absence of NaCl. The NaCl dependence of the stability is different from that of the activity, suggesting that the effects of NaCl on activity and stability are independent. Thermolysin has been demonstrated to be not only a thermophilic enzyme but also a highly halophilic one.

Production of lactic acid from discarded bread by using an amylolytic lactic acid bacterium, Lactobacillus amylovorus, was investigated to recycle bakery wastes. Addition of 2.0% yeast extract in the medium containing 3.58% bread crust caused maximum acid production. The stimulation of lactic acid production by less expensive materials such as corn steep liquor, defatted soybean powder, rice bran and wheat bran at additional levels of 2.0% was also observed, but limited. Acid production in the medium supplemented with 2.0% corn steep liquor was enhanced by the further addition of 2.0% defatted soybean powder and reached the levels comparable to medium containing 1.4% yeast extract. In the medium supplemented with 2.0% corn steep liquor and 2.0% defatted soybean powder, 47.2% of total sugars was converted to dl-lactic acid in 72 h under static incubation. When the baking test was carried out, the bread made with the addition of the culture filtrate was significantly (P < 0.05) preferred over those with and without addition of commercial fermented seasoning with respect to taste and overall acceptability.

DC susceptibility, specific heat and inelastic neutron scattering measurements have been performed on the metallic pyrochlore compound Pr 2 Ir 2 O 7 . No anomalies indicative of a magnetic phase transition were found for temperatures greater than 1.8 K. Our experiments and analysis show that Pr 3+ ground state is a well-isolated magnetic doublet with Ising-like moments of ∼3.0 μ B oriented along the local 〈111〉 direction of each tetrahedral unit.

A method of interferometry which interferes convergent electron beams by means of an electron biprism, CBED + EBI, is presented. The method requires an electron biprism which is placed below the specimen and in between any two or more convergent beams. The biprism compensates the convergent beams deviation angle by means of an applied potential. When overlaid the diffracted beams interfere to produce an interferogram. Theoretical and practical descriptions of the CBED + EBI method are presented, as well as some of its special features such as its ability to interfere high spatial frequency beams, to produce high contrast fringes and to measure the electron beam's coherency.

Five strains were isolated from soil as fungi able to degrade both poly(3-hydroxybutyrate) (PHB) and polycaprolactone (PCL), and one of the strains, D218, identified as Paecilomyces lilacinus, was selected. In 10 d, D218 degraded PHB almost completely and 10% of the PCL, each at 0.1% in the culture media. Strain D218 excreted PHB and PCL depolymerases in media containing either PHB, PCL or PHB plus PCL. Both depolymerase activities were reduced when the medium was supplemented with either soluble starch, lactose or glucose. The optimum conditions for PHB depolymerase were pH 6.5 to 7.5 at 50°C, while those for PCL depolymerase were pH 3.5 to 4.5 at 30°C. In the reaction mixtures used for the enzyme assays, the formation of 3-hydroxybutyrate from PHB and e-caprolactone from PCL was confirmed by high performance liquid chromatography.

Thin silicon solar cells with a Non-Reflective front Surface (NRS), a passivated rear surface and locally diffused BSF structure have been considered to be hopeful candidates as space solar cells of the next generation. In this paper, the electrical properties of textured surface cells and flat (non-textured) surface cells are compared and the surface recombination velocity S e of these cells are discussed. Then, the electrical properties of 10 Ω cm substrate cells and 2 Ω cm substrate cells are compared and the carrier recombination at the rear Si/SiO 2 interface is discussed using energy band diagrams.

Electron holography using an improved phase-shifting (fringe-scanning) interferometric technique is described. The improvements it makes in phase measurement, in spatial resolution of reconstructed images and in hologram formation are clarified and demonstrated with three experiments: (1) quantitative detection of atomic surface steps on molybdenite crystal film, (2) topographic measurement of gold platelets epitaxially grown on a molybdenite substrate, and (3) sensitive observation of a bacterial flagellum filament.

The system described here provides video-rate observation by using a liquid-crystal spatial light modulator as a rewritable electron-hologram medium. Time-sequential interference micrographs are produced by superimposing a plane reference wave on the object wave reconstructed from the hologram displayed on the modulator. Experimental observations of the magnetic field of a barium ferrite particle and of dynamic domain-wall motion in a thin ferromagnetic film are shown. The sources of error in system are discussed, and a distortion-free system is proposed.

This paper reports the use of Fraunhofer in-line electron holography to visualize an undecagold cluster, which has been virtually invisible by conventional bright-field transmission electron microscopy (TEM), by taking advantage of the coherent electron beam of high brightness from a 200 kV cold field-emission gun and thus making the full use of phase contrast and avoiding radiation damage. Theoretical and experimental investigations of contrast of an in-line hologram show that phase contrast can be maximized by using an appropriate defocusing distance according to the wavelength of illuminating electrons and the size of the object. A parameter termed Fresnel number is found to be important in considering the optimum experimental conditions, especially when in-line electron holography is applied to weak-phase objects.

Dynamic behavior of magnetic domains in a thin permalloy film has been observed by on-line real-time electron holography. Electron holograms formed in a transmission electron microscope equipped with an electron biprism are detected by a TV camera and transferred to a liquid-crystal spatial light modulator (LC-SLM) located at the output port of a Mach-Zehnder interferometer. Interference micrographs, where magnetic flux lines are directly visualized, are obtained by superimposing a plane wave onto an object wave reconstructed from the hologram in the LC-SLM. Using this system, dynamic behavior of magnetic domains in the magnetization or demagnetization processes is clearly observed.

A 1.7 kb DNA fragment containing both the zliE and zliS genes complements the sucrose-deficiency of the mutant, Z6C-S2, derived from Zymomonas mobilis ATCC 29191, and the mutant containing both genes produces sucrose-hydrolyzing enzymes extracellularly. The mutant containing zliE accumulates the enzymes within the cells, while that containing zliS does not produce the enzymes (Kondo, T. et al. , Biosci. Biotech. Biochem., 58, 526–530, 1994). In the mutant cells containing zliE , most of the sucrose-hydrolyzing enzymes were bound on the cell surface, and these enzymes were liberated when incubated with either washing, suspension or extract of the cells containing zliS . These results suggest that a product of the zliS gene affects the cell membrane to stimulate the liberation of cell-associated proteins.

Optimal culture conditions for the production of β-mannanase and β-mannosidase were investigated in Enterococcus casseliflavus FL2121 isolated from decayed Konjac. The bacterium secreted β-mannanase to the culture medium and produced a cell-associated β-mannosidase. Synthesis of these enzymes was induced by mannan and mannooligosaccharides, respectively, under alkaline conditions. β-Mannanase activity in the medium increased gradually during 24 h and was constant for up to 72 h, while β-mannosidase activity was the highest in the cells cultured for 8 h. Neither treatment by ultrasonic oscillation nor detergents solubilized β-mannosidase from the cells without loss of enzyme activity. Optimum pH and temperature for crude β-mannosidase were 6·0 to 7·4 and 50°C.

When Saccharomyces cerevisiae FL2209, a baking strain isolated from commercial compressed yeast, was cultured in YPS medium composed of 2% Bacto-yeast extract, 4% Bacto-peptone, 2% sucrose, 0·2% sucrose, 0·2% KH2PO4 and 0·1% MgSO4.7H2O (pH 6·0), it showed higher leavening abilities in three types of doughs compared to those of the commercial compressed yeast, but not in sweet dough. Addition of NaCl to YPS medium resulted in the increase of leavening abilities in all of the doughs tested. Effects of NaCl were further investigated in seven other yeast strains including six S. cerevisiae strains and one Torulaspora delbrueckii strain. NaCl commonly elevated the leavening abilities of five-maltose-fermenting S. cerevisiae strains in dough without addition of sugar. Sweet dough leavening was stimulated by NaCl in only one strain of S. cerevisiae. Leavening abilities of T. delbrueckii were reduced when cultured in the presence of NaCl. YPS medium with the addition of NaCl was shown to be available to estimate the potential leavening abilities of most yeast strains.

It is confirmed experimentally and theoretically that the strong Fresnel diffraction disturbing electron microscope images of crystal surfaces in the profile-imaging mode is greatly reduced by means of observing the phase distribution of electron waves. High-resolution electron holography affords this clear observation of the surface, and it is shown how each electron potential of Mg and O atoms on a MgO (001) surface extends into a vacuum.

Ultrafiltration, a useful technique in biological process, is unsuitable for the separation of solutes of similar molecular weights. If the sizes of the solutes are changeable, however, their separation may be possible. Salting in and salting out result from the change of state of a solute with the concentration of coexisting salt. The application of these phenomena to modification of the characteristics of ultrafiltration was examined. The ultrafiltration of papain (MW 23,400) and dextran (MW 19,600) as single solutes and as a mixture was carried out in a stirred-type ultrafiltration cell with a membrane having a molecular weight cut-off of 100,000. With single solutes, the ultrafiltration characteristics of papain and dextran were different, even when their concentrations were lower than their solubilities; the rejection coefficients for papain were much larger than for dextran. In the ultrafiltration of the mixture at a salt concentration of 25 w/w%, not only papain but a part of the dextran was retained in the retentate solution. At a salt concentration of 8 w/w%, however, dextran was deriven through with the permeate solution but the rejection coefficient for papain was high. Thus, in spite of their similar molecular weights, papain and dextran are separable by ultrafiltration by changing their sizes in the solution.

Two β-mannanases (M-I and M-II) were purified from the culture filtrate of Enterococcus casseliflavus FL2121 by ammonium sulfate precipitation, column chromatography of DEAE-Toyopearl 650M and Phenyl-Toyopearl 650M and preparative polyacrylamide gel electrophoresis to homogenities. The molecular weights of M-I and M-II were estimated to be 142,000 and 137,000 by SDS-polyacrylamide gel electrophoresis and 127,000 and 113,000 by gel filtration, respectively. M-I and M-II exhibited an optimum pH at 6.0 and an optimum temperature at 50°C. The enzymes were activated slightly by CoCl 2 and MnCl 2 , and inhibited strongly by AgNO 3 , HgCl 2 , EDTA, and N -bromosuccinimide. The K m values of M-I and M-II for konjac β-1,4-glucomannan were 0.14 and 0.30 (mg/ml), and the maximum velocities were 1,110 and 1,700 (U/mg protein), respectively. Both enzymes were endo-type β-mannanases hydrolyzing mannosides larger than β-1,4- d -mannotetraose.

Four tryptophan residues in cyclomalto-oligosaccharide (cycloamylose, cyclodextrin) glucanotransferase (CGTase) from Bacillus stearothermophilus were modified with N -bromosuccinimide (NBS), one of which (“Trp 4 ”) was markedly less reactive than the others. The modification of Trp 4 by NBS corresponded with inactivation of the CGTase-catalysed hydrolysis of cyclomaltohexaose (CG 6 ). Trp 4 was protected against NBS by glucose and the maltosaccharides G 2 –G 4 , which indicates Trp 4 to be located at the substrate binding site of CGTase.

Cytosine deaminase (EC 3.5.4.1) from Aspergillus fumigatus IFO 5840, which is the first cytosine deaminase to be found in a mould, was purified 150-fold with an overall yield of 0.75%, to homogeneity judging from disc and SDS-polyacrylamide gel electrophoresis. The enzyme was a monomer of 32 kDa. Besides cytosine, the enzyme stoichiometrically deaminated 5-methylcytosine and 5-fluorocytosine: the activity toward them was 100:28:43, and the apparent K m values for them were 2, 36, and 6.5 mM, respectively. The enzyme had a pH optimum at around pH 7 and temperature optimum at 35°C. The enzyme activity was inhibited by heavy metal ions such as Fe 2+ , Cu 2+ , Hg 2+ , and Pb 2+ at 0.1 mM, and by p -chloromercuribenzoate, o -phenanthroline, ATP, and UTP at 1 mM.

Zymomonas mobilis IFO 13756 (ATCC 29191) produces three kinds of sucrose-hydrolyzing enzymes, E1, E2, and E3. Extracellular enzymes E2 and E3 bound to the cell surface were released from cells by suspension in 20 mM potassium phosphate buffer (pH 7.0) and incubation at 30°C for 10 min with gentle shaking. After centrifugation of the cell suspension, E3 was isolated from the supernatant as crystals in a 52-fold purification. The enzyme consisted of a monomer subunit having a molecular mass of 58 kDa and its isoelectric point was pH 3.2. The N-terminal amino acid sequence was MFNFNASRWTRAQAMKVNKFDL. The enzyme catalyzed the hydrolysis of sucrose, and was identified as an invertase that had a strict substrate specificity for sucrose. The optimum pH and temperature were pH 5.5 and 50°C, respectively. Thiol reagents inhibited the enzyme activity markedly.