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The structural determinants of chlorogenic acid esterase (CE) substrate specificity are poorly understood. Here, we establish how a Lactobacillus helveticus CE selects for its substrate, chlorogenic acid (CGA). We determine that a Lys residue in an extended loop over the active site imparts substrate specificity by hydrogen bonding to CGA. Mutation of the Lys residue abolishes CGA specificity. Comparison with other bacterial CEs reveals that the extended loop is not conserved. However, the hydrogen bonding functionality to CGA is preserved thanks to other residues. Structural comparison with ferulic acid esterases (FAEs), a related enzyme class, shows that CEs feature a more restricted active site, reflecting the fact that they hydrolyze smaller substrates compared to FAEs.

Systematic study of nano-fiber formation by He plasma irradiation on period 6 metals (Ta, W, Re, Ir, Pt, Au) was performed. Under the same He plasma irradiation conditions (flux, fluence, and ion energy), long nano-fibers were produced on W, Re, and Ir among which the nano-fibers on Re had the highest growth rate. On the other hand, Ta, Pt and Au did not show long nano-fibers (slight nano-fiber formation was seen on Pt). The transition metals in favor of the nano-fiber formation are stiff materials with high Young's and shear moduli. In addition, stiff materials tend to have high He binding energies with He clusters at vacancies. It is speculated that stiffness could contribute to generation of high stress field and high pressure He bubble formation, which are possibly important for nano-fiber formation.

The results of studying the La2–xSrxCuO4 (x = 0.077−0.195) crystals with the microwave absorption, direct current resistance and magnetic susceptibility measurements are presented. The doping-temperature phase diagram with the boundaries of the areas with charge density waves, superconducting fluctuation and the bulk superconductivity state is plotted. The doping range of the charge density wave existence is found to be broader than that obtained from the X-Ray Diffraction study. It spreads at least down to x = 0.077.

We investigated the inter-level time-dependent dielectric breakdown (VTDDB) degradation mechanisms in Cu/low-k damascene structures. Considering the dependence of VTDDB reliability and ILD film properties on the post etching treatment (PET) condition, it was found that defect generation near the anode-side interface impacts the VTDDB lifetime and that the absolute value of the lifetime could be improved by reducing the number of Si-H bonds near the anode side. On the other hand, the electric field acceleration factor is independent of the anode-side defects, which is discussed based on the "Impact Damage model." Furthermore, we demonstrated experimentally the relationship between the intra-level TDDB (LTDDB) and the VTDDB failure mechanisms.

Difference of helium (He) agglomeration energies between period 6 elements, tantalum (Ta), tungsten (W), iridium (Ir) and gold (Au), is illustrated by using first principles calculations based on density functional theory (DFT). It is found that He in W and Ir can agglomerate more easily than Ta and Au. We investigate a relationship between the He agglomeration tendency and the growth of nanostructure by He plasma irradiation. Thus, the four metals are exposed to He plasma irradiation. Each metal has different structures after the He plasma exposure. Surface nanostructures of W and Ir are fuzzy fiber-like while these structures are not observed in Ta and Au. In the meantime, W and Ir have a tendency to agglomerate He atoms at a vacancy or interstitial sites easily. This correlation suggests that the He agglomeration may play a role for understanding the fuzz formation mechanism. Keywords: Helium plasma induced structures, Fuzz, Nanostructures, Density functional theory

The upper critical field of a cuprate high-temperature superconductor, La1.84Sr0.16CuO4, was investigated by high-frequency self-resonant contactless electrical conductivity measurements in magnetic fields up to 102 T. An irreversible transition was observed at 85 T (T = 4.2 K), defined as the upper critical field. The temperature-dependent upper critical field was argued on the basis of the Werthamer-Helfand-Hohenberg theory. The Pauli-limiting pair-breaking process with a small contribution of the spin-orbit coupling explained the first-order phase transition exhibiting a hysteresis observed at low temperatures.

We revisit the classical problem of the molecular orientation inside a hybrid cell filled with liquid-crystals with various elastic constant anisotropies by means of Monte Carlo simulations using t...

Fluctuations of various order parameters are considered as the significant components of understanding the mechanism of high-Tc superconductivity. To study these fluctuations in the cuprate and Fe-based superconductors we use the joint measurements of direct current resistivity and non-resonant microwave absorption. Comparing data obtained with both methods allowed us to extract the contribution of dynamic charge density waves in La2−xSrxCuO4, superconducting fluctuations in Bi2Sr2Ca1−xYxCu2O8 and nematic fluctuations in FeTe1−xSex. © Kazan Federal University (KFU). Government Council on Grants, Russian Federation Government Council on Grants, Russian Federation Russian Academy of Sciences, RAS Kazan Federal University This work was supported by the Russian Academy of Sciences via the grant of Program 1.12 “Fundamental Problems of High-Temperature Superconductivity”. The work of D.Ch. is supported by the program 211 of the Russian Federation Government, agreement No. 02.A03.21.0006 and by the Russian Government Program of Competitive Growth of Kazan Federal University. The work of A.V. has been supported by Act 211 of the Government of Russian Federation, Contracts No. 02.A03.21.0006 and No. 02.A03.21.0011.

Highly reliable ferroelectric (FE) Hf 0.5 Zr 0.5 O 2 (HZO) film with Al nanoclusters embedded by sub-monolayer doping technique is demonstrated for the first time. Al nanoclusters increase the remnant polarization (Pr) and reduce the voltage necessary for polarization switching. Furthermore, the program and erase endurance at the cycle of more than 250k and the Pr retention at 85°C for 10 years are achieved. Al nanoclusters are formed by the partial oxidation of submonolayer metallic Al embedded in HZO films. Al nanoclusters enhance the large grain growth of orthorhombic-phase HZO during FE-HZO crystallization annealing. The reduction of grain boundaries caused by the large grain growth with Al nanoclusters effectively reduces the leakage current in the HZO film. As a result, reliability of the FE HZO film is significantly improved.

A laboratory experiment was conducted by varying the undersurface area of nesting substratum and the number of females in an experimental tank to elucidate the determinants of the mating pattern in the stream goby, Rhinogobius sp. cross-band type. Males with larger nests tended to attract two or more females to their nest in a tank. Moreover, males spawned simultaneously with multiple females and entire brood cannibalism by males was rarely observed under a female-biased sex ratio. When males spawned with a single female with low fecundity, however, entire brood cannibalism occurred at a high frequency, suggesting that a male guarding a nest with fewer eggs consumes the brood. Therefore, spawning behaviour of females that leads to a large egg mass would decrease the risk of entire brood cannibalism. In this species, simultaneous spawning by multiple females in a nest serves as a female counter-measure against entire brood cannibalism. These results suggest that a conflict of interest between the sexes through brood cannibalism is a major determinant of simultaneous spawning.

The occurrence of a second magnetization peak (SMP) on the dc magnetization curves of superconducting single crystals with random quenched disorder in increasing external magnetic field H is quite common. Many models for this intriguing phenomenon have been proposed so far, but its origin is still under strong debate. Optimally doped and overdoped La2−xSrxCuO4 single crystals (x ≥ 0.15) exhibit an SMP over a large temperature interval, up to very close to the critical temperature. By decreasing doping, it was found that with H oriented along the c axis the SMP completely disappears in the doping domain of well developed static charge and spin stripes (x ∼ 1/8), reappearing for x ≤ 0.10. This behaviour follows the instability of the Bragg vortex glass generated by the static stripe order (as revealed by small-angle neutron scattering experiments), which is confirmed by our magnetization relaxation measurements. If H is along the (a, b) planes, the SMP is observed for all investigated specimens. The presented analysis supports the scenario in which the SMP is generated by the pinning-induced disordering of the low-field Bragg vortex glass in the dynamic conditions of dc magnetic measurements.

Hydrogen adsorption on graphene-supported metal clusters has brought much controversy due to the complex nature of the bonding between hydrogen and metal clusters. The bond types of hydrogen and graphene-supported Ti clusters are experimentally and theoretically investigated. Transmission electron microscopy shows that Ti clusters of nanometer size are formed on graphene. Thermal desorption spectroscopy captures three hydrogen desorption peaks from hydrogenated graphene-supported Ti clusters. First-principles calculations also found three types of interaction: two types of bonds with different partial ionic character and physisorption. The physical origin for this rests on the charge state of the Ti clusters: when Ti clusters are neutral, H2 is dissociated, and H forms bonds with the Ti cluster. On the contrary, H2 is adsorbed in molecular form on positively charged Ti clusters, resulting in physisorption. Thus, this work clarifies the bonding mechanisms of hydrogen on graphene-supported Ti clusters.

A laboratory experiment was conducted by varying the undersurface area of nesting substratum and the number of females in an experimental tank to elucidate the determinants of the mating pattern in the stream goby, Rhinogobius sp. cross-band type. Males with larger nests tended to attract two or more females to their nest in a tank. Moreover, males spawned simultaneously with multiple females and entire brood cannibalism by males was rarely observed under a female-biased sex ratio. When males spawned with a single female with low fecundity, however, entire brood cannibalism occurred at a high frequency, suggesting that a male guarding a nest with fewer eggs consumes the brood. Therefore, spawning behaviour of females that leads to a large egg mass would decrease the risk of entire brood cannibalism. In this species, simultaneous spawning by multiple females in a nest serves as a female counter-measure against entire brood cannibalism. These results suggest that a conflict of interest between the sexes through brood cannibalism is a major determinant of simultaneous spawning.

We have observed 7 new transits of the `hot Jupiter' WASP-5b using a 61 cm telescope located in New Zealand, in order to search for transit timing variations (TTVs) which can be induced by additional bodies existing in the system. When combined with other available photometric and radial velocity (RV) data, we find that its transit timings do not match a linear ephemeris; the best fit \chi^2 values is 32.2 with 9 degrees of freedom which corresponds to a confidence level of 99.982 % or 3.7 \sigma. This result indicates that excess variations of transit timings has been observed, due either to unknown systematic effects or possibly to real TTVs. The TTV amplitude is as large as 50 s, and if this is real, it cannot be explained by other effects than that due to an additional body or bodies. From the RV data, we put an upper limit on the RV amplitude caused by the possible secondary body (planet) as 21 m s^{-1}, which corresponds to its mass of 22-70 M_{Earth} over the orbital period ratio of the two planets from 0.2 to 5.0. From the TTVs data, using the numerical simulations, we place more stringent limits down to 2 M_{Earth} near 1:2 and 2:1 mean motion resonances (MMRs) with WASP-5b at the 3 \sigma level, assuming that the two planets are co-planer. We also put an upper limit on excess of Trojan mass as 43 M_{Earth} (3 \sigma) using both RV and photometric data. We also find that if the possible secondary planet has non- or a small eccentricity, its orbit would likely be near low-order MMRs. Further follow-up photometric and spectroscopic observations will be required to confirm the reality of the TTV signal, and results such as these will provide important information for the migration mechanisms of planetary systems., Comment: accepted for publication in PASJ, 30 pages, 8 figures, 8 tables

We have measured the temperature dependence of the magnetic susceptibility, χ vs. T, and the magnetization curve, M vs. H, for NbSe2 single crystals, in order to compare the superconducting (SC) state in the overdoped regime of La2−xSrxCuO4 (LSCO) with the SC state of the layered conventional superconductor NbSe2. While a plateau in χ vs. T in a moderate magnetic field and a so-called second peak in M vs. H, which is due to the marked enhancement of vortex pinning, have been observed in the overdoped regime of LSCO, these behaviors have not been observed in NbSe2. The present results indicate that the anomalously marked enhancement of vortex pinning is a characteristic feature in the overdoped LSCO where a microscopic phase separation into SC and normal-state regions takes place.

The safety and effectiveness of islet transplantation has been proven through world-wide trials. However, acute and chronic islet loss has hindered the ultimate objective of becoming a widely used treatment option for type 1 diabetes. A large islet loss is attributed, in part, to the liver being a less-than-optimal site for transplantation. Over half of the transplanted islets are destroyed shortly after transplantation due to direct exposure to blood and non-specific inflammation. Successfully engrafted islets are continuously exposed to the liver micro-environment, a unique immune system, low oxygen tension, toxins and high glucose, which is toxic to islets, leading to premature islet dysfunction/death. Investigations have continued to search for alternate sites to transplant islets that provide a better environment for prolonged function and survival. This article gathers courses and conditions that lead to islet loss, from organ procurement through islet transplantation, with special emphasis on hypoxia, oxidative stress, and antigen non-specific inflammation, and reviews strategies using pharmacological agents that have shown effectiveness in protecting islets, including a new treatment approach utilizing siRNA. Pharmacological agents that support islet survival and promote β-cell proliferation are also included. Treatment of donor pancreata and/or islets with these agents should increase the effectiveness of islets transplanted into extrahepatic sites. Furthermore, the development of methods designed to release these agents over an extended period, will further increase their efficacy. This requires the combined efforts of both islet transplant biologists and bioengineers.

Type I secretion system (TISS) of Gram-negative bacteria permits proteins to be secreted directly from the cytoplasm to the external medium by a single, energy-coupled step. To examine whether this system can be used as an extracellular production system of recombinant proteins, Escherichia coli alkaline phosphatase (AP) was fused to a C-terminal region of Pseudomonas sp. MIS38 lipase (PML) and examined for secretion using the E.coli cells carrying the heterologous TISS. PML is one of the passenger proteins of TISS and contains 12 repetitive sequences and a secretion signal at the C-terminal region. The fusion protein was efficiently secreted to the extracellular medium, while AP was not secreted at all, indicating that the secretion of AP is promoted by a secretion signal of PML. The repetitive sequences were not so important for secretion of the fusion protein, because the secretion level of the fusion protein containing entire repeats ( approximately 10 mg/l culture) was only 2-fold higher than that of the fusion protein without repeats. The fusion protein purified from the culture supernatant existed as a homodimer, like AP, and was indistinguishable from AP in enzymatic properties and stability.

Fe3O4 possesses unique properties such as high Curie temperature and half-metallic nature and therefore can function as a high-spin-polarized electrode in spintronic devices. In order to use this compound in such devices, the magnetic characteristics of multilayers used in these devices, which include Fe3O4, should be highly controllable. In this study, we fabricated Fe3O4/Pt or Cr (0-10 nm)/Fe systems through epitaxial growth on MgO(110) substrates in order to investigate the magnetic coupling in Fe3O4 and metallic hybrid systems. We found that these two systems show a marked difference in the dependence of the coercive field (H-c) of the Fe layer on the nonmagneticmetal- layer thickness. Hc for the system with Pt showed variation characteristics of interlayer exchange coupling in metal systems, while H-c increased monotonically with the thickness of the Cr layer.

Group 5 elements (niobium and tantalum) and group 6 elements (molybdenum and tungsten) were exposed to helium plasma, and the resulting surface structures were observed by electron microscopy. Group 5 elements showed hole structures, where the size of the holes ranged from several tens of nm to a few hundred nm in diameter, while group 6 elements showed fiber-like structures. As a first step in understanding such differences, the difference in helium agglomeration energies and changes in the stress tensor as a function of the number of He atoms at interstitial sites were investigated for each element using density functional theory. The calculations revealed that helium atoms prefer to agglomerate in both of these groups. However, helium in group 6 elements can agglomerate more easily than group 5 elements due to higher binding energy. These results indicate a possible correlation between the shape of helium plasma induced surface nanostructures and the atomic level properties due to helium agglomeration.

PGE2 is a major prostanoid that regulates inflammation by stimulating EP1-4 receptors. However, how PGE2 induces an initial inflammatory response to vascular hyper-permeability remains unknown. Here we investigated the role of the PGE2 -EP receptor signal in modulating vascular permeability both in vivo and in vitro.We used a modified Miles assay and intravital microscopy to examine vascular permeability in vivo. Endothelial barrier property was assessed by measuring transendothelial electrical resistance (TER) in vitro.Local administration of PGE2 , an EP2 or EP4 receptor agonist into FVB/NJcl mouse ear skin caused vascular leakage, indicated by dye extravasation. Intravital microscopy and laser Doppler blood-flow imaging revealed that these treatments dilated peripheral vessels and increased local blood flow. Pretreatment with the vasoconstrictor phenylephrine inhibited the PGE2 -induced blood flow increase and vascular leakage. In contrast to the EP2 and EP4 receptor agonists, administration of an EP3 receptor agonist suppressed vascular leakage without altering vascular diameter or blood flow. In isolated HUVECs, the EP3 receptor agonist elevated TER and blocked thrombin-induced dextran passage. Inhibiting PKA restored the hypo-permeability induced by the EP3 receptor agonist.Activation of the PGE2 -EP2 or -EP4 receptor signal induces vasodilatation in mural cells, resulting in increased local blood flow and hyper-permeability. In contrast, activation of the PGE2 -EP3 receptor signal induces a cAMP-dependent enhancement of the endothelial barrier, leading to hypo-permeability. We provide the first evidence that endothelial cells and mural cells cooperate to modulate vascular permeability.

The purpose of the present study was to examine vibratory patterns of the neoglottis and to ascertain the neoglottic conditions that could cause failure in tracheoesophageal shunt phonation. We studied 30 tracheoesophageal shunt speakers while using "trap-door" type voice prostheses. Videostroboscopy was undertaken to investigate vibratory patterns of the neoglottis during phonation of the sustained vowel sound /e/ in these patients. The voice qualities of the patients were judged perceptually. A regular neoglottic vibration was observed in 21 patients. Nine patients had irregular neoglottic vibrations. In this latter group, two patients had incomplete neoglottic closures with breathy voices, four patients had multiple contacts of several mucosal walls with rough voices, and three patients had tight neoglottic closures with strained voices. During stroboscopic evaluation of tracheoesophageal shunt phonation, regularity of the neoglottic vibration may be the most significant finding. These findings show that it is as important to evaluate neoglottic vibration in alaryngeal voicing as it is to study glottic vibration in laryngeal voicing. Stroboscopic examination may be a help to elucidate a cause of failure in cases of poor tracheoesophageal shunt speech.

Fusion performance of reversed shear discharges with an {ital L}-mode edge has been significantly improved in a thermonuclear dominant regime with up to 2.8 MA of plasma current in the JT-60U tokamak. The core plasma energy is efficiently confined due to the existence of persistent internal transport barriers formed for both ions and electrons at a large minor radius of r/a{approximately}0.7 near the boundary of the reversed shear region. In an assumed deuterium-tritium fuel, the peak fusion amplification factor defined for transient conditions involving the dW/dt term would be in excess of unity. {copyright} {ital 1997} {ital The American Physical Society}

Electrochemical insertion of lithium ions into V2O5 bronze containing nickel (NiV2O5, Ni V = 0.075 ) was studied by comparing with V2O5. The difference in the amount of lithium inserted up to the second plateau was about 0.15 between NiV2O5 and V2O5 on open circuit voltage (OCV) curves. The broadened reduction and oxidation peaks in cyclic voltammogram, indistinct plateaux in discharge curve, and wide gap between OCV and discharge potential observed on NiV2O5 suggested that nickel ions in the bronze are placed in the same sites as lithium and disturb lithium diffusion along the channels of V2O5 structure. The present results implied that two factors, charge balance and lattice sites, governed the insertion of foreign ions, such as Li+ and Ni2+, into V2O5 lattice.

Fabrication of a deep field stop layer is the key to backside process of IGBT. The shallow-implanted P-dopant was far deeply activated by Pulse-cw hybrid laser annealing. The approach leads to the low-cost process without MeV-class implantation.

A cytosolic peptide-GTP complex that stimulates l-isoproterenol-responsive adenylate cyclase activity was identified in the rat liver. The peptide component was purified and characterized with regard to its interaction with GTP. The peptide was isolated as a complex form with GTP on a Sephadex G-25 column in 1 mM NaHCO3, and was purified as a dissociated form, with relative molecular weight (M(r)) approximately 3,000 and GTP-binding ability, in 200 mM ammonium acetate. The purified peptide alone displayed little stimulatory effect on adenylate cyclase activity, but its reassociated form with GTP clearly enhanced the effect of GTP on the enzyme activity. The isoproterenol competition curve using l-[3H]dihydroalprenolol as an antagonist ligand shifted to lower affinity by the addition of the peptide reassociated with GTP (16.5-fold shift), whereas the same concentration of GTP (1 microM) or the peptide alone had little or no effect (1.5- or 0.9-fold shift, respectively). Furthermore, the peptide enhanced the GTP effect in response to l-isoproterenol but not to glucagon, prostaglandin E1, or fluoride. These results suggest that the cytosolic peptide potentiates the effect of GTP on the agonist-beta-adrenergic receptor-stimulatory guanine nucleotide-binding regulatory component of the adenylate cyclase ternary complex.

A neurotrophic factor that supports the development of cholinergic retinal neurons was purified from media conditioned by a primary culture of embryonic hippocampal neurons. Retinal choline acetyltransferase (ChAT), which is located exclusively in amacrine cells, served as a marker for the development of retinal cholinergic neurons. In a serum-free control culture, retinal neurons from 17-day-old rat fetus displayed little increase in the enzyme activity and a low proportion of neurite-bearing cells (15-20%) within 7 days. The conditioned media, when added to the retinal neuron culture, dose-dependently increased ChAT activity and the number of neurite-bearing cells (40-60%), the maximum ChAT activity being approximately sixfold higher than that in the control. The fraction with these stimulatory activities was purified by Sephadex G-15 column chromatography and two times reverse-phase HPLC. The final fraction showed approximately 3,000-fold higher purification as compared with that in the Sephadex G-15 fraction. Gas-phase protein sequencing analysis of the final fraction yielded a peptide sequence: Tyr-Leu-Leu-Pro-Ala-Gln-Val-Asn-Ile-Asp. A synthetic peptide with this sequence dose-dependently stimulated ChAT activity in the retinal cell culture and dissociated cell culture of the septal nucleus. These findings suggest that the developing hippocampal neurons produce a neurotrophic peptide that stimulates the development of cholinergic neurons.

Periodontitis is a localized infectious disease caused by periodontopathic bacteria such as Porphyromonas gingivalis (P. gingivalis), and the severity correlates to significance of immune responses. Recently, it has been reported that periodontitis is associated with the development of systemic disease such as diabetes and atherosclerosis because of increasing invasion of oral pathogens to the circulation. However, the association between local and systemic infectious responses is still unclear. In the present study, we examined the differences of biological responses in animals with or without bacterial infection. After Balb/c mice were infected subcutaneously with live P. gingivalis W83, serum, skin and liver were collected according to experimental protocol. The skin and liver tissues were observed pathologically by haematoxylin-eosin staining, and serum IL-6 levels were measured using ELISA method. Throughout the experimental period, conditions of the mice were observed continuously. As expected, severe infiltration of leukocytes were observed at inflamed skin corresponding to the number of bacterial challenges. Although no inflammatory appearance of skin was observed, serum IL-6 levels were increased dramatically (P0.01, Student's t-test) and liver tissues were injured in the mice without bacterial challenge. Interestingly, although severe inflammatory appearance of the skin was observed, serum IL-6 levels were not increased and no inflammatory responses were observed in the liver of the 3-times bacterially challenged group. Importantly, immunoglobulin G against P. gingivalis W83 was detected in the blood of mice with 3-times bacterial challenge corresponding to improvement of weight loss and survival. In conclusion, although multiple infections develop severe localized inflammation, the immune system should be sufficient to protect the systemic inflammatory responses.