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Streptomyces coelicolorA3(2) possesses nine genes for family 18 chitinases and two for family 19, showing high multiplicity. By hybridization analyses, distribution of those chitinase genes was investigated in six other Streptomycesspecies covering the whole phylogenetic range based on 16S rDNA sequences. All strains showed high-multiplicity of chitinase genes, like S. coelicolorA3(2). The phylogeny and gene organization of the family 18 chitinase genes cloned from Streptomycesspecies so far were then analyzed to investigate the gene evolution. It was concluded that Streptomycesalready possessed a variety of chitinase genes prior to branching into many species, and that the ancestral genes of chiAand chiBhave been generated by gene-duplication. In the course of the analyses, evidence that the chi30and chi40genes of S. thermoviolaceuswere derived from their corresponding original chitinase genes by losing gene parts for substrate-binding domains and fibronectin type III-like domains was obtained. It was thus shown that gene-duplication and domain-deletion were implicated in generating the high diversity and multiplicity of chitinase genes in Streptomycesspecies.

The first total synthesis of a marine-derived potent antitumor antibiotic, (±)-spiroxin C, was achieved via a TBAF-activated Suzuki−Miyaura cross-coupling reaction as a key step, which was also shown to be useful for the synthesis of sterically hindered binaphthyl derivatives.

Abstract:  The concentrations of bisphenol A (BPA) contained in landfill leachates from solid waste disposal sites were measured. The concentrations of BPA contained in leachates from industrial waste sites were in the range below the detection limit to 2800 μg/l, while those from municipal sites were in the range 26–8400 μg/l. The leachates from ash-rich sites contained relatively lower concentrations of BPA compared with organic-rich leachates. It is suggested that BPA concentration increases with time after the completion of reclamation in the case of ash-rich sites, whereas the concentration of BPA decreases with time in the case of organic-rich sites. A 7-year survey on a site in Japan showed neither a decrease nor an increase in the concentration of BPA during on-going reclamation. A leachate from a site in the Philippines contained high concentrations of BPA. A slight positive correlation was found between BPA concentrations and total organic carbon (TOC). A major portion of the BPA in leachates was found in dissolved and organic unassociated fractions, which cannot be precipitated by coagulation. More than 99.9% of the BPA contained in raw leachates was removed by a conventional series of treatment processes consisting of biological treatment, coagulation, sedimentation, sand filtration, and activated carbon adsorption.

Nanosized silicon carbide (SiC) dots are grown by low-energy mass-selected ion beam deposition (MSIBD) on 4°-off Si(111) substrates at temperatures of 800–950°C and examined by atomic force microscopy (AFM). We find that the size distribution and the geometrical arrangement of SiC dots strongly depend on the substrate temperature, i.e. highly uniform SiC dots are formed at 800°C and 850°C; in particular, SiC dots are arranged in lines when the deposition temperature is as low as 800°C. These results indicate that self-assembled SiC dots can be prepared on misoriented substrates at low deposition temperatures. Copyright © 2003 John Wiley & Sons, Ltd.

Nanosized silicon carbide (SiC) dots are grown by low‐energy mass‐selected ion beam deposition (MSIBD) on 4°‐off Si(111) substrates at temperatures of 800–950°C and examined by atomic force microscopy (AFM). We find that the size distribution and the geometrical arrangement of SiC dots strongly depend on the substrate temperature, i.e. highly uniform SiC dots are formed at 800°C and 850°C; in particular, SiC dots are arranged in lines when the deposition temperature is as low as 800°C. These results indicate that self‐assembled SiC dots can be prepared on misoriented substrates at low deposition temperatures. Copyright © 2003 John Wiley & Sons, Ltd.

In order to monitor the crustal deformation in the area of eastern Kanto, central Japan, Ibaraki University has started the high precision geodetic studies with GPS measurements in collaboration with Geographical Survey Institute of Japan (GSI). The first measurements were taken in 1991 with a small network of 8 sites. Four more sites were included since 1998 for a better coverage in the region. In the present study, we analyzed the data collected since 1998 by using the GAMIT/GLOBK software for estimating the displacement vectors in the ITRF96 reference frame. The data from the continuous GPS network of GSI and the GPS sites of IGS close to the studied region (Tsukuba and Usuda) were included for obtaining the primary solutions. The initial results by constraining the co-ordinates of the IGS stations nearest to the network confirmed the repeatability of the baseline components. The results presented here were obtained by assuming the 4 fiducial stations around the network, namely, Irkutsks (IRKT), Fairbanks (FAIR), Sheshan (SHAO) and Dededo (GUAM). The average uncertainties of the horizontal velocities from three consecutive campaigns, each separated by six months, were estimated to be ±4.6 mm/yr and ±3.5 mm/yr for the northward and eastward components, respectively.

Diastereoselective reduction of 6-bromo-6-substituted penicillanate esters has been achieved by treatment with tributylphosphine to give 6-substituted penicillanate esters. This reaction would appear to proceed through a phosphonium β-lactam enolate species, followed by a diastereoselective protonation. This method has the advantage of being simple to carry out and it is mild, gives high diastereoselectivity, and should tolerate a number of functional groups in the substrates. Implications of these observations are discussed.

Lithium ion secondary batteries are currently the best portable energy storage device for the consumer electronics market. The recent development of the lithium ion secondary batteries has been achieved by the use of selected carbon and graphite materials as an anode. The performance of lithium ion secondary batteries, such as the charge/discharge capacity, voltage profile and cyclic stability, depend strongly on the microstructure of the anode materials made of carbon and graphite. Due to the contribution of the carbon materials used in the anode in last five years, the capacity of the typical Li ion battery has been improved 1.7 times. However, there are still active investigations to identify the key parameters of carbons that provide the improved anode properties, as carbon and graphite materials have large varieties in the microstructure, texture, crystallinity and morphology, depending on their preparation processes and precursor materials, as well as various forms such as powder, fibers and spherule. In the present article, we describe the correlation between the microstructural parameters and electrochemical properties of conventional and novel types of carbon materials for Li ion batteries, namely, graphitizable carbons such as milled mesophase pitch-based carbon fibers, polyparaphenylene-based carbon heat-treated at low temperatures and boron-doped graphitized materials, by connecting with the market demand and the trends in Li ion secondary batteries. The basic scientific theory can contribute to further developments of the Li ion batteries such as polymer batteries for consumer electronics, multimedia technology and future hybrid and electric vehicles.

To clarify the pathological and clinical significance of periglomerular alpha-smooth muscle actin (alpha-SMA)-positive cells, we examined 51 needle-biopsy specimens from patients with human glomerulonephritis. Immunoelectron microscopy confirmed these cells were myofibroblasts showing characteristic features with abundant alpha-SMA-positive thin myofilaments. Nonsclerotic glomeruli with periglomerular myofibroblasts were larger in the Bowman's capsular planar area than nonsclerotic glomeruli without periglomerular myofibroblasts (24.7 +/- 6.0 x 10(3) microm2 v 19.9 +/- 8.5 x 10(3) microm2; P < 0.01). We studied the correlation between the clinical prognosis and the extent of periglomerular myofibroblasts in 24 patients with IgA nephropathy. Patients were divided into two groups; those with plasma creatinine levels within normal range at biopsy and significantly elevated at follow-up were designated group 1 (poor prognosis), and patients with plasma creatinine levels within normal range at biopsy and not significantly elevated at follow-up were designated group 2 (fair prognosis). In the kidneys of group 1 patients, periglomerular alpha- SMA was expressed more intensively than it was in the kidneys of group 2 patients (alpha-SMA expression score, 1.0 +/- 0.48 v 0.52 +/- 0.54; P < 0.05). These findings indicate that periglomerular myofibroblasts appeared surrounding the nonsclerotic hypertrophic glomeruli, which may lead finally to glomerulosclerosis. This report suggests that interaction between the glomerular cells and the periglomerular myofibroblasts may have a role in the progression of glomerular diseases. (Am J Kidney Dis 1998 Sep;32(3):419-25)

Photoinduced reaction in relations to water photolysis was studied on Pt- or other catalysts-supported TiO2 (P-25) particles. It was found that stoichiometric H2 and O2 formation does not take place with the photocatalyst, and only H2 production was observed. A long-term water photolysis was carried out by Pt-supported TiO2 (TiO2/Pt) to produce H2, in which H2 formation stopped almost after 600 h irradiation. After recovering the TiO2/Pt particles used in the long-term reaction, they were reused in a photocatalytic H⁺ reduction by adding methanol as an electron donor, but no H2 production was observed showing that the TiO2/Pt particles have lost their photocatalytic activity after the long-term reaction. These results suggest that TiO2 itself works as an electron donor to produce H2. Structural change of the TiO2/Pt have been studied by both X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) before and after the photoreaction. In both the XRD and XPS, the structure of the original TiO2 almost disappeared after the photoreaction and new structures appeared, showing that Ti⁴⁺ changed irreversibly to a higher valance state (Ti⁵⁺) after producing H2.

Abstract:  The purpose of this study was to characterize the nature and structure of procedural memory. We have previously studied the process of learning sequential behavioral procedures using monkeys. The monkey’s task was to press five consecutive pairs of buttons (indicated by illumination) in the correct order for every pair, which he had to find by trial-and-error in a block of trials. The whole sequence was called a “hyperset”; each pair was called a “set”. We first examined whether monkeys learned to perform a hyperset as a single sequence or learned the order of button-presses individually for each set. To answer this question, we generated hypersets that were the same as the hypersets that had been extensively learned except that the order of the sets was reversed. The performance of these “reversed hypersets” was much worse than the performance of the original learned hypersets and was similar to the performance of new hypersets, as regards both the number of errors and the performance time. The result suggests that monkeys learned a hyperset as a sequence. To examine whether the learned performance was specific to the hand used for practice, we had monkeys use the same hand throughout the long-term practice of each hyperset, and then tested the opposite hand. The performance using the opposite hand was worse than the performance using the trained hand, but was better than the performance for new hypersets. This indicates that the memory for the sequential procedure is only partially accessible to the hand that was not used for the practice.

To evaluate hearing levels in Chinese young people, audiometry was carried out at a rural village in Shandong Prefecture. The subjects were 282 healthy school children and students ranging in age from 7ȁ17 y. All subjects were asked to complete a brief questionnaire on otological symptoms, personal histories and use of noisy playthings. Audiometric threshold testing was performed at the audiomeric frequencies of 0.5, 1, 2, 4 and 8 kHz. Cluster analysis was used to estimate the associations between questions in the questionnaire and hearing impairment. Fifty-six subjects (20% subjects) were excluded from the normal groups. Twenty-two ears of the excluded subjects showed 4 kHz-dip and 38 ears showed high frequency hearing loss. An increased prevalence of hearing impairment was found when compared with young Japanese (1% from the nationwide school health survey) and with young Chinese in Shandong Prefecture (0.5%). In the questionnaire, 4 questions on dizziness, head trauma, aminoglycoside administration, and suspicion of Meniere's syndrome, were included in the cluster of hearing impairment. The cause of this hearing impairment was proposed to be the potentiating effects of aminoglycoside antibiotics and exposure to noise.

In the treatment and therapy of patients suffering a stroke, it is very important to predict whether viable neurones, even those of poor function, remain intact in the lesions of the brain. To determine whether viable neurones of low functional activity are represented in in vivoneuroreceptor imaging, we undertook experiments in gerbils with cerebral infarction, in which we examined histological changes and the results of dual-tracer in vivoautoradiography of glucose utilization with 14C-labelled deoxyglu-cose and benzodiazepine receptor binding with 123I-labelled Ro 16–0154. The unrelated findings of cerebral glucose metabolism and benzodiazepine receptor binding were observed in the primary infarct lesion and in remote areas, including the ipsilateral striatum and thalamus.

Iomazenil is a specific ligand for central-type benzodiazepine receptors (BZR). In order to determine the clinical significance of the findings of 123I-iomazenil single photon emission tomography (SPET) in cerebrovascular disease (CVD), we compared the cerebral uptake of 123I-iomazenil with oxygen metabolism measured by positron emission tomography (PET). Depending on the severity of the haemodynamic and/or metabolic impairment based on our institutional criteria [a reduction of < 30.6 ml 100 g-1min-1in cerebral blood flow (CBF) and an increase of > 0.52 in the oxygen extraction fraction (OEF)], the cortical areas were classified into four groups as follows: Group I, normal CBF and OEF; Group II, normal CBF and increased OEF; Group III, reduced CBF and normal OEF; Group IV, reduced CBF and increased OEF. Seven patients (mean age 65 ± 7 years) with CVD underwent both PET and 123I-iomazenil SPET within 8 days. The ratios of the mean counts in 14 regions of interest in the cerebral cortices to those in the cerebellar cortices (R/C ratios) were compared with the cerebral metabolic rate of oxygen (CMRO2). The R/C ratios of Group IV were lower than those of Group I (P< 0.005). The R/C ratios correlated with CMRO2in Group III (r= 0.577, P< 0.01) and in Group IV (r= 0.707, P< 0.005), but not in Groups I or II. These results suggests that reduced uptake in 123I-iomazenil SPET reflects oxidative hypometabolism causing neuronal damage in haemodynamically and metabolically impaired areas in patients with CVD. This information may be valuable when deciding therapeutic approaches.

In order to study the effects of fluctuating infrasound, rats were exposed to traffic noise. Responses of the pituitary adrenocortical system were evaluated by the plasma ACTH and corticosterone concentration.The plasma ACTH concentration increased significantly in rats exposed to fluctuating infrasound at 100 dB and 110 dB (Leq) as compared with the controls. No significant increase of the plasma ACTH concentration was found in rats exposed to 110 dB steady-state infrasound.According to these results, the effect of fluctuating infrasound is greater than that of steady-state infrasound.

To clarify the physiological effects of infrasound, 42 day-old male Wistar rats were exposed to 16Hz infrasound at 120 B for 28 days. We measured body weight, spontaneous running activity, and urinary 17-OHCS levels. The exposure group was exposed to infrasound in the exposure chamber and the control group was housed in the same chamber without exposure. Each group was further subdivided into two subgroups, a sedentary group and an exercise group. The exercise group was housed with a rotating wheel cage adjoining the feed cage. It was found that:The growth was slower in the exposure group than in the control group.Spontaneous running activity of the exposure group increased significantly from 20 days after the start of infrasound exposure.Urinary 17-OHCS levels increased in 3 days after the start of infrasound exposure.These results suggested that infrasound acted as a stressor.

Polyurethane/polypeptide block copolymers were synthesized. Infrared spectroscopy and differential scanning calorimetry revealed that in the block copolymers both segments undergo phase-mixing, while in polyurethane/polypeptide blend both components undergo phase-separation. Contact angle measurement showed that in the block copolymers polyurethane segments tended to appear on the membrane surface, whereas in polyurethane/polypeptide blend polypeptide components appeared on the membrane surface. In vitro nonthrombogenicity of the block copolymers was similar to that of homopolymers or polymer blends, though adhesion and deformation of platelets were suppressed on the block copolymer membranes.

1. To characterize procedural learning and memory, we devised a behavioral paradigm that allows us to examine the process of learning of new procedures, repeatedly and without serious difficulties for primate subjects. We trained two monkeys to perform a sequential button press task. Upon pressing of a home key, 2 of 16 (4 x 4 matrix) light-emitting diode (LED) buttons (called "set") were illuminated simultaneously, and the monkey had to press them in a predetermined order that he had to find out by trial-and-error. A total of five sets (called "hyperset") was presented in a fixed order for completion of a trial; an error at any set aborted the trial. A given hyperset was repeated as a block of experiment until 20 successful trials were performed. Monkeys PI and BO experienced 313 and 92 hypersets, respectively. Most of these hypersets were experienced only once (1 block of experiment); the others (28 hypersets for monkey PI and 14 hypersets for monkey BO) were chosen for extensive practice. 2. The learning, indicated as the decrease in the number of trials to criterion and the decrease in the performance time, proceeded at three levels: 1) short-term and sequence-selective learning that occurred by repeating a particular hyperset during a block of experiment; our monkeys learned, to some degree, to perform a new hyperset within a short period (< 5 min); 2) long-term and sequence-selective learning that took place for each hyperset across days; by daily practice, they further improved their skills for performing the particular hyperset; and 3) long-term and sequence-unselective learning that was indicated by the improvement of performance for new hypersets; the monkeys were required to learn many hypersets, each just once (a block of trials), in which they performed gradually better with more experiences in the 2 x 5 task. 3. To examine whether the memory was retained for a long period, we had the monkey learn 12 hypersets sufficiently, then we stopped the training and retested them after 1 or 6 mo. After the 1-mo interruption the performance was significantly better than that for new hypersets. After the 6-mo interruption the performance was not different from new hypersets in terms of the number of trials but was significantly better than new hypersets in terms of the performance time. The results suggest that motor memory (measured by performance time) can be retained longer than procedural memory (measured by the number of trials).

We describe the generation of a mouse whole chromosome library using sequence-independent polymerase chain reaction (PCR) to amplify sequences contained in DNA extracted from flow sorted chromosomes. DNA in sorted chromosomes from a human × mouse hybrid cell line was digested with a frequent four-cutter restriction enzyme, Sau3Al, and the ends were ligated to an adapter oligonucleotide. The ligated DNA fragments were amplified using PCR primers homologous to the linker-adapter oligonucleotide. PCR-generated products were characterized by gel electrophoresis. The size of the amplified DNA ranged from 100 to more than 1000 bp with a relatively high proportion of products at approximately 400 bp. Biotinylated PCR products used for FISH showed specific hybridization to murine metaphases and no hybridization to human lymphocyte and hamster metaphase cells. Banding analysis indicated that the probes were specific for mouse Chromosome 11. We anticipate that availability of painting probes for specific murine chromosomes will facilitate cytogenetic studies in the mouse.