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High-entropy materials have attracted considerable interest due to their unique, improved properties and large configurational entropy. Out of these, high-entropy ceramics (HECs) are of particular interest since the independent solubility of cations and anions results in increased configurational entropy. However, most HEC research considers only a single element occupying the anion sublattice, which limits the maximum attainable configurational entropy. Here, we expand our previous work on high-entropy borocarbides where both boron and carbon occupy the anion sublattice. By applying an ab initio based screening procedure, we identify six elements Li, Ti, V, Zr, Nb and Hf suitable for forming high-entropy borocarbides. With these elements, we propose six novel HEC compositions, and by computing their entropy forming ability, we identify that three are likely to form single-phase during synthesis. Material properties and lattice distortions for all proposed compositions are studied using density functional theory calculations with special quasirandom structures. The directional lattice distortions, a concept we introduce in this work, show that lattice distortions have an elemental and directional preference for certain HEC compositions. We also show that the novel inclusion of Li improves the mechanical properties of the proposed HECs, the details of which are studied using the electron localization function.

We report the optical observation of lead-vacancy (PbV) centers in diamond fabricated by Pb ion implantation and subsequent high-temperature annealing (2100 {\deg}C) under high pressure (7.7 GPa). Their optical properties were characterized by photoluminescence at varying temperatures down to 5.7 K. We observed intense emission peaks at 550 and 554 nm with a large splitting of approximately 3900 GHz. The two lines are thought to correspond to the zero phonon line (ZPL) of PbV centers with split ground and excited states. A cubic trend of the ZPL width was observed while varying temperature. We performed polarization measurements of the two lines in a single PbV center, showing nearly orthogonal dipole polarizations. These optical measurements strongly indicate that the PbV center possesses D3d symmetry in the diamond lattice. The observed large ground state splitting significantly suppresses the phonon-mediated transition, which causes decoherence of the electron spin state of the group IV color centers in diamond, expecting a long spin coherence time at a temperature of approximately 8 K.

We herein report the case of a 79-year-old man who presented with right-sided heart failure (HF) 27 years after undergoing surgery for tetralogy of Fallot. The HF did not respond well to oral diuretics. Transthoracic echocardiography and chest X-ray failed to determine the cause of the HF for three years. An intrapericardial mass located just behind the sternum, was finally identified on computed tomography. The mass had compressed the right ventricle, causing right-sided HF. Pre-surgical diagnostic images led to suspicion of a chronic expanding intrapericardial hematoma (CEIH), and the CEIH was surgically removed. The patient's symptoms improved markedly.

Despite the advanced understanding of combustion, the mechanisms of subsequent light emission have not attracted much attention. In this work, we model the light emission as electronic excitation throughout the oxidation reaction. We examined the simple dynamics of the collision of an oxygen molecule (O2) with a kinetic energy of 4, 6, or 10 eV with a stationary target molecule (Mg2, SiH4 or CH4). Time-dependent density functional theory was used to monitor electronic excitation. For a collision between O2 and Mg2, the electronic excitation energy increased with the incident kinetic energy. In contrast, for a collision between O2 and SiH4 molecules, a substantial electronic excitation occurred only at an incident kinetic energy of 10 eV. The electronic excitation was qualitatively reproduced by analysis using complete active space self-consistent field method. On the other hand, collision between O2 and CH4 molecules shows reflection of these molecules indicating that small-mass molecules could show neither oxidation nor subsequent electronic excitation upon collision with an O2 molecule. We believe that this work provides a first step toward understanding the light-emission process during combustion.

First-principles simulations were used to investigate water (H2O) decomposition induced by a femtosecond laser with high flux ∼1 × 1020 photons/(sec cm2 ). One goal of our research is to find metamaterials that locally enhance the laser field to reduce the threshold laser intensity required to decompose H2O molecules. In this work, small-diameter (6.3 Å) single-walled carbon nanotubes were found to reduce the threshold power by 90% compared with the power required to decompose H2O in the gas phase. The present results suggest a strategy for the design of materials with high energy efficiency for H2O decomposition based on polarizability and morphology (curvature) to enhance the local field. We demonstrate that carbon nanotubes enhance the local field resulting in a power enhancement of approximately eight times., X.C. acknowledges financial support from the National Natural Science Foundation of China (Grant No. 11774248). A.R. acknowledges financial support from the JSPS Fellowship program, the European Research Council (Grant No. QSpec-NewMat ERC-2015-AdG-694097), and Grupos Consolidados (Grant No. IT578-13).

Recent advances in ultrashort laser pulse techniques have opened up a wide variety of applications in both fundamental physics and industrial fields. In this work, $ab\phantom{\rule{4pt}{0ex}}initio$ molecular dynamics simulations based on time-dependent density functional theory revealed a steady deceleration of lattice distortion propagation in an aluminum slab with increasing laser pulse intensity. Analyzing the interatomic force revealed a significant reduction in the harmonic terms and nonmonotonic growth of anharmonicity. This is characterized by spatially nonuniform force screening by plasmon under a nonperturbative excitation condition that is not captured in Born--Oppenheimer molecular dynamics, and is consistent with the current interpretation of laser-induced periodic structure patterning. This work highlights the significance of collective electronic excitations for modeling the structure formation in such a system.

First-principles calculations of electron-ion dynamics based on real-time time-dependent density functional theory were performed to study the lattice dynamics in yttrium aluminum garnet (YAG) doped with cerium (Ce) following photoexcitation. The dynamics induced by the optical transitions from the valence band to the conduction band of the YAG host and from the Ce 4f to 5 d levels were examined. Significant lattice motion was observed in the latter case. This lattice motion (Franck-Condon relaxation) decreased the Ce–O bond length by 0.05 A and increased the energy of the Ce 4f level by 0.5 eV, suggesting a Stokes shift in the light emission due to the Ce 5 d→4f transition. The calculated Stokes shift is consistent with the recently reported experimental value, despite the approximations used in the present calculations. The effect of lattice temperature was also examined up to 300 K.

In this study, first-principles time-dependent density functional theory calculations were used to demonstrate the possibility to modulate the amplitude of the optical electric field (E-field) near a semiconducting graphene nanoribbon. A significant enhancement of the optical E-field was observed 3.34 Å above the graphene nanoribbon sheet, with an amplitude modulation of approximately 100 fs, which corresponds to a frequency of 10 THz. In general, a six-fold E-field enhancement could be obtained, which means that the power of the obtained THz is about 36 times that of incident UV light. We suggest the use of semiconducting graphene nanoribbons for converting visible and UV light into a THz signal., HZ and XLC acknowledge financial support from the National Natural Science Foundation of China (Grant No. 11474207 and Grant No. 11374217). YM acknowledges the fund from MEXT, Grant-in-Aid for Scientific Research on Innovative Areas “Science of Atomic Layers (SATL)”, Japan, and the support from Research organization of Information Science and Technology (RIST) at Tokyo. AR acknowledges financial support from the European Research Council Advanced Grant DYNamo (ERC-2010-AdG-267374), Spanish Grant (FIS2013-46159-C3-1-P), Grupos Consolidados UPV/EHU del Gobierno Vasco (IT578-13) and COST Actions CM1204 (XLIC) and MP1306 (EUSpec).

Tin-vacancy (SnV) color centers were created in diamond by ion implantation and subsequent high temperature annealing up to 2100 {\deg}C at 7.7 GPa. The first-principles calculation suggests that the large atom of tin can be incorporated into the diamond lattice with a split-vacancy configuration, in which a tin atom sits on an interstitial site with two neighboring vacancies. The SnV center shows a sharp zero phonon line at 619 nm at room temperature. This line splits into four peaks at cryogenic temperatures with a larger ground state splitting of ~850 GHz than those of color centers based on other IV group elements, silicon-vacancy (SiV) and germanium vacancy (GeV) centers. The excited state lifetime was estimated to be ~5 ns by Hanbury Brown-Twiss interferometry measurements on single SnV quantum emitters. The order of the experimentally obtained optical transition energies comparing with the SiV and GeV centers is good agreement with the theoretical calculations., Comment: 10 pages, 4 figures and Supplementary 3 pages, 2 figures

We use time-dependent density functional theory to study laser-pulse induced decomposition of H2O molecules above the two-dimensional (2D) materials graphene, hexagonal boron nitride, and graphitic carbon nitride. We examine femtosecond-laser pulses with a full width at half maximum of 10 or 20 fs for laser-field intensity and wavelengths of 800 or 400 nm by varying the intensity of the laser field from 5 to 9 V/Å, with the corresponding range of fluence per pulse up to 10.7J/cm2. For a H2O molecule above the graphitic sheets, the threshold for laser-field H2O decomposition is reduced by more than 20% compared with that of an isolated H2O molecule. We also show that hole doping enhances the water adsorption energy above graphene. The present results indicate that the graphitic materials should support laser-induced chemistry and that other 2D materials that can enhance laser-induced H2O decomposition should be investigated., Y.M. acknowledges funding from JSPS KAKENHI Grants No. JP16H00925, No. JP16H04103, and No. JP16K05049. Y.M. also acknowledges support from the Research Organization of Information Science and Technology (RIST), Tokyo. H.Z. and X.C. acknowledge financial support from the National Key R&D Program of China 2017YFA0303603 and the National Natural Science Foundation of China (Grants No. 11474207 and No. 11374217). A.R. acknowledges financial support from the JSPS Fellowship program and from the European Research Council (QSpecNewMat ERC-2015-AdG-694097) and Grupos Consolidados (IT578-13).

In this study, we investigated the effect of dorsomorphin, a selective inhibitor of bone morphogenetic protein (BMP) signaling, on rat PC12 pheochromocytoma cell differentiation. PC12 cells can be induced to differentiate into neuron-like cells possessing elongated neurites by nerve growth factor, BMP2, and other inducers. Cells were incubated with BMP2 and/or dorsomorphin, and the extent of neurite outgrowth was evaluated. Unexpectedly, BMP2-mediated neuritogenesis was not inhibited by co-treatment with dorsomorphin. We also found that treatment with dorsomorphin alone, but not another BMP signaling inhibitor, LDN-193189, induced neurite outgrowth in PC12 cells. To further understand the mechanism of action of dorsomorphin, the effects of this drug on intracellular signaling were investigated using the following signaling inhibitors: the ERK kinase (MEK) inhibitor U0126; the tropomyosin-related kinase A inhibitor GW441756; and the protein kinase A (PKA) inhibitor H89. Dorsomorphin induced rapid and sustained ERK1/2 activation; however, dorsomorphin-mediated ERK1/2 activation and neuritogenesis were robustly inhibited in the presence of U0126 or H89, but not GW441756. These findings suggest that dorsomorphin has the potential to induce neuritogenesis in PC12 cells, a response that requires the activation of PKA-dependent MEK-ERK1/2 signaling.

Non-equilibrium dynamics induced by the femtosecond laser shot has attracted high attentions in condensed matter community. Interaction between a strong field of light and materials cannot be treated by conventional perturbation theory that assumes both electron wave functions and ionic positions as insensitive to the field. Direct approach for computing real-time propagations of electron wave packet and ionic positions under presence of strong optical field is one of promising solutions. In this review, I present theoretical approaches based on the time-dependent density functional theory and show some examples of ultra-fast dynamics in materials induced by the femtosecond laser shots: exfoliation of graphene layer from graphite and photochemical reaction of molecules encapsulated inside carbon nanotubes.

The laser flash photolysis process of diazomethane has been studied by using a real time propagation time-dependent density functional theory (RTP-TDDFT) combined with molecular dynamics. The activation energy barrier for disintegrating diazomethane into nitrogen (N(2)) and carbene (CH(2)) molecules significantly decreases in the electronic excited S(1) state compared to that in the S(0) ground state. Furthermore, the produced carbene molecule can be in the electronic excited state of (1)CH(2) ((1)B(1)) instead of the lowest state among singlet states (1)CH(2) ((1)A(1)), which is evident in the wave function characteristics of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) throughout the disintegration. This is regarded as the initial stage of the rearrangement in the excited state (RIES), the evidence of which has been given by experiments in the past decade. In the RIES mechanism scheme, we suggest that the photoreaction in the S(1) state contributes considerably to the photochemistry of carbene formation. The passing near the S(1)/S(0) conical intersection, which allows the transition to ground state diazomethane producing the lowest singlet state carbene molecule, is considered a rare event from our molecular dynamics, although this has been regarded as the dominant mechanism in previous theoretical studies.

We examined real-time-propagation time-dependent density functional theory (rtp-TDDFT) coupled with molecular dynamics (MD), which uses single-particle representation of time-evolving wavefunctions allowing exchange of orbital characteristics between occupied and empty states making the effective Kohn-Sham Hamiltonian dependent on the potential energy surfaces (PESs). This scheme is expected to lead to mean-field average of adiabatic potential energy surfaces (PESs) and is one of Ehrenfest (mean-field) approaches. However, we demonstrate that the mean-field average can be absent in simulating photoisomerization of azobenzene and ethylene molecules. A transition from the S2 to the S1 excited state without the mean- field average was observed after examining several rtp-TDDFT-MD trajectories of a photoexcited azobenzene molecule. The subsequent trans-cis isomerization was observed in our simulation, which is consistent with experimental observation and supported by previous calculations. The absence of the mean-field average of PESs was also observed for the transition between the S1 and S0 states, indicating that the MD simulation was on a single PES. Conversely, we found no transition to the ground state (S0 state) when we performed a MD simulation of an S1 excited ethylene molecule owing to the constraint on the occupation number of each molecular orbital. Thus, we conclude that, at least for azobenzene and ethylene molecules, the rtp-TDDFT-MD is an on-the-fly simulation that can automatically see the transition among the PESs of excited states without the mean-field average unless the simulation reaches the PES of the S0 state.

Atomic-sized fluorescent defects in diamond are widely recognized as a promising solid state platform for quantum cryptography and quantum information processing. For these applications, single photon sources with a high intensity and reproducible fabrication methods are required. In this study, we report a novel color center in diamond, composed of a germanium (Ge) and a vacancy (V) and named the GeV center, which has a sharp and strong photoluminescence band with a zero-phonon line at 602 nm at room temperature. We demonstrate this new color center works as a single photon source. Both ion implantation and chemical vapor deposition techniques enabled fabrication of GeV centers in diamond. A first-principles calculation revealed the atomic crystal structure and energy levels of the GeV center.

We used cross-sectional high-resolution transmission electron microscopy to directly observe the atomic structures at SiO2/Si and Si3N4/Si interfaces. These observations provided the first direct evidence that cristobalite-like crystalline SiO2 exists at the interface. Our observations also show that in one of the observed N-induced interfacial geometries, a N atom replaces a Si atom at the second interfacial layer, and a dangling bond was produced on a Si atom adjacent to the N atom. We thus argue that a large elastic strain at a crystalline SiO2/Si interface probably plays an important role in preserving the initial atomic-scale flatness of the interface; that is, the strain results in layer-by-layer oxidation. Furthermore, we infer that the difference in interfacial flatness between Si3N4/Si and SiO2/Si can be explained in terms of the difference in their interfacial strain.

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY)., We propose a transient interlayer compression in two-dimensional compound materials by using an intense IR laser resonant with the out-of-plane optical phonon mode (A2u mode). As a test case, we studied bilayer hexagonal boron nitride (h-BN), which is one of the compound layered materials. Excited state molecular dynamics calculations using time-dependent density functional theory show an 11.3% transient interlayer contraction of h-BN due to an interlayer dipole-dipole attraction of the laser-pumped A2u mode. These results are applicable to other layered compound materials. Such layered materials are a good material for nanospace chemistry, e.g., intercalating molecules and acting with them, and IR irradiation to contract the interlayer distance could provide a new route for chemical reactions under pressure. The duration of the contraction is at least 1 ps in the current simulation, which is observable by high-speed electron-beam diffraction measurements., Y. M. acknowledges the support by MEXT Grants-in-Aid for Scientific Research on Innovative Areas “Science of Atomic Layers” (Projects No. 2506, No. 26107534). H. Z. acknowledges financial support from the National Natural Science Foundation of China (NSFC. Grant No. 11474207). A. R. acknowledges the financial support from the European Research Council Advanced Grant DYNamo (No. ERC-2010- AdG-267374), Spanish Grant (No. FIS2013-46159-C3-1-P), Grupos Consolidados UPV/EHU del Gobierno Vasco (No. IT578-13), and European Community FP7 Project CRONOS (Grant No. 280879-2), and COST Actions Grants No. CM1204 (XLIC) and No. MP1306 (EUSpec).

Nitrogen-vacancy (NV) centers in diamond have attracted significant interest because of their excellent spin and optical characteristics for quantum information and metrology. To take advantage of the characteristics, the precise control of the orientation of the N-V axis in the lattice is essential. Here we show that the orientation of more than 99 % of the NV centers can be aligned along the [111]-axis by CVD homoepitaxial growth on (111)-substrates. We also discuss about mechanisms of the alignment. Our result enables a fourfold improvement in magnetic-field sensitivity and opens new avenues to the optimum design of NV center devices., 14 pages, 4 figures, To be published in Applied Physics Express

Ab initio molecular orbital theory was used to examine the physisorption of a hydrogen molecule on planar and curved graphene clusters. The repulsive nature of a H2−H2 interaction and the small dependence of physisorption energies on physisorption sites favor a close-packed structure for molecular hydrogen physisorption on a planar graphene. It was also found that the physisorption energies are significantly increased on curved graphenes.

Nitrogen-vacancy (NV) centers in diamond have attracted a great deal of attention because of their possible use in information processing and electromagnetic sensing technologies. We examined theatomistic generation mechanism for the NV defect aligned in the [111] direction of C(111) substrates. We found that N is incorporated in the C bilayers during the lateral growth arising from a sequence of kink propagation along the step edge down to [-1,-1,2]. As a result, the atomic configuration with the N-atom lone-pair pointing in the [111] direction is formed, which causes preferential alignment of NVs. Our model is consistent with recent experimental data for perfect NV alignment in C(111) substrates., Comment: 5 pages, 4 figures

We have used first-principles simulations based on time-dependent density functional theory to show that short laser pulses can trigger preferential hydrogen desorption from the upper or lower side of suspended graphane (H-terminated graphene). This control is achieved by using intense ultrashort p-polarized laser pulses (∼2 fs) with an asymmetric time envelope. The dynamical Stark effect induced by the pulse creates an asymmetric charge distribution and force field on the H ions, even at low laser fluence. At finite temperatures the carbon-hydrogen stretching softens, favoring H desorption from one side. This transient geometry can be modified by halogen functionalization, which results in a two-dimensional dipolar structure., H.Z. acknowledges financial support from the National Natural Science Foundation of China (NSFC Grant No. 11074176 and NSAF Grant No. 10976019) and support from Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20100181110080). Y.M. acknowledges the fund from the Strategic Programs for Innovative Research (SPIRE), MEXT, and the Computational Materials Science Initiative (CMSI), Japan. A.R. acknowledges funding from European Research Council Advanced Grant DYNamo (ERC-2010-AdG -Proposal No. 267374), Spanish projects (FIS2010-21282-C02-01 and PIB2010US-00652), Grupos Consolidados UPV/EHU del Gobierno Vasco (IT-319-07), ACI-Promociona (ACI2009-1036), European Community project THEMA (Contract No. 228539), Ikerbasque, and SGIker ARINA (UPV/EHU).

Nanoscale molecular confinement substantially modifies the functionality and electronic properties of encapsulated molecules. Many works have approached this problem from the perspective of quantifying ground-state molecular changes, but little is known about the nonequilibrium dynamics of encapsulated molecular system. In this letter, we report an analysis of the nonequilibrium dynamics of acetylene (C2H2) inside a semiconducting carbon nanotube (CNT). An ultrashort high-intense laser pulse (2 fs width and 1015 W/cm2 intensity) brings the systems out of equilibrium. This process is modeled by comprehensive first-principles time-dependent density-functional simulations. When encapsulated, acetylene dimer, unlike a single acetylene molecule, exhibits correlated vibrational dynamics (C–C bond rotation and H–C–C bending) that is markedly different from the dynamics observed in the gas phase. This result highlights the role of CNT in modulating the optical electric field within the tube. At longer simulation timescales (> 20 fs) in the largest-diameter tube studied here [CNT(14,0)], we observe synchronized rotation about the C–C axes in the dimer and ultimately ejection of one of the four hydrogen atoms. Our results illustrate the richness of photochemical phenomena in confined geometries., Y.M. acknowledges the support of the Research Organization of Information Science and Technology at the Tokyo Office, and support by the Strategic Programs for Innovative Research, Ministry of Education, Cultural, Sports, Science, and Technology (Japan) and the Computational Materials Science Initiative (Japan). H.Z. is supported by the National Natural Science Foundation of China (under NSFC Grant 11074176) and the support from Research Fund for the Doctoral Program of Higher Education of China (Grant 20100181110080). A.R. acknowledges financial support from the European Research Council Advanced Grant DYNamo (ERC-2010-AdG-Proposal 267374), the Spanish (FIS2011-65702-C02-01 and PIB2010US-00652 ), ACI Promociona (ACI2009-1036), Grupos Consolidados UPV/EHU del Gobierno Vasco (IT-319-07), and Ikerbasque foundation.

Helium ion microscopy (HIM), which was released in 2006 by Ward et. al., provides non- destructive imaging of nano-scale objects with higher contrast than scanning electron microscopy. HIM measurement of suspended graphene under typical conditions was simulated by first-principles time-dependent density functional theory and the 30 keV He+ collision was found to induce the emission of electrons dependent on the impact point. This finding suggests possibility of obtaining a highly accurate image of the honeycomb pattern of suspended graphene by HIM. Comparison with a simulation of He0 under the same kinetic energy showed that electron emission is governed by the impact ionization instead of Auger process initiated by neutralization of He+., H.Z. acknowledges financial support from the National Natural Science Foundation of China (NSFC Grant No. 11074176 and NSAF Grant No. 10976019) and support from the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20100181110080). Y.M. acknowledges funding from the Strategic Programs for Innovative Research (SPIRE), MEXT, the Computational Materials Science Initiative (CMSI), Japan, and support from the Research Organization of Information Science and Technology (RIST), Tokyo. A.R. acknowledges funding from the European Research Council Advanced Grant DYNamo (ERC-2010-AdG -Proposal No. 267374), Spanish Projects (No. FIS2010-21282-C02-01 and No. PIB2010US-00652), Grupos Consolidados UPV/EHU del Gobierno Vasco (IT-319-07), Ikerbasque and SGIker ARINA (UPV/EHU), and CRONOS (Contract No. 280879-2).

The effects of a mixture of three peptidase inhibitors (PIs), amastatin, captopril and phosphoramidon, on methionine-enkephalin (Met-enk)-, β-endorphin (β-end)-, dynorphin-(1-13) (Dyn)- and electroacupuncture (EA)-induced antinociception were compared in rats. EA was performed by passing electric pulses (3 Hz, 0.1-msec duration, for 45 min) through acupuncture needles inserted into the Hoku-point. The antinociceptive effect was estimated by the hind paw pressure test. The antinociceptive effects of Met-enk and β-end injected i.c.v. or i.t. and of Dyn injected i.t. were clearly potentiated by the PIs pretreated by the same administration routes as used for the injection of opioid peptides. The antinociceptive effects of Met-enk, β-end and Dyn injected i.c.v. were also potentiated significantly by i.t.-PIs. PIs injected into the periaqueductal gray (PAG) potentiated EA antinociception. However, the EA effect was not affected by i.t.-PIs and was rather attenuated by i.c.v.-PIs. These results suggest that: i) Met-enk hydrolyzing enzymes are involved in the degradation of not only Met-enk but also β-end and Dyn in the rat central nervous system; ii) Met-enk and β-end act on both supraspinal and spinal sites, while Dyn acts only on the spinal site; iii) EA antinociception is mediated by supraspinal Met-enk and/or β-end; and iv) an anti-opiate peptide system may be activated by EA stimulation, being susceptible to Met-enk hydrolyzing enzymes.

In this study, we investigated the effect of dorsomorphin, a selective inhibitor of bone morphogenetic protein (BMP) signaling, on rat PC12 pheochromocytoma cell differentiation. PC12 cells can be induced to differentiate into neuron-like cells possessing elongated neurites by nerve growth factor, BMP2, and other inducers. Cells were incubated with BMP2 and/or dorsomorphin, and the extent of neurite outgrowth was evaluated. Unexpectedly, BMP2-mediated neuritogenesis was not inhibited by co-treatment with dorsomorphin. We also found that treatment with dorsomorphin alone, but not another BMP signaling inhibitor, LDN-193189, induced neurite outgrowth in PC12 cells. To further understand the mechanism of action of dorsomorphin, the effects of this drug on intracellular signaling were investigated using the following signaling inhibitors: the ERK kinase (MEK) inhibitor U0126; the tropomyosin-related kinase A inhibitor GW441756; and the protein kinase A (PKA) inhibitor H89. Dorsomorphin induced rapid and sustained ERK1/2 activation; however, dorsomorphin-mediated ERK1/2 activation and neuritogenesis were robustly inhibited in the presence of U0126 or H89, but not GW441756. These findings suggest that dorsomorphin has the potential to induce neuritogenesis in PC12 cells, a response that requires the activation of PKA-dependent MEK-ERK1/2 signaling.

The No. 10 recovery boiler for Tomioka Mill was completed in May 1990 and KP plant No. 3 which was completed in August 1990.This boiler is a higher pressure, temperature, thermal efficiency and low pollutants emission recovery boiler of the largest class in Japan. 50% of the steam requirement in Tomioka Mill is produced by this boiler.At the first stage, the plugging that was characteristic of kraft recovery boilers occured in the supperheater and the evaporator. For the past two years, we have doing monthly burning tests of black liquor fuel.Now, with the experience of two years operation, we have improved the operation method of this recovery boiler. The following is the report of the No. 10 boilers operation.

4 páginas, 5 figuras.-- PACS numbers: 82.37.Vb, 81.05.U-, 81.07.De, 82.50.-m, We show by first-principles simulations that ultrafast laser pulses induce different chemical reactions in a molecule trapped inside a nanotube. A strong laser pulse polarized perpendicular to the tube axis induces a giant bond stretch of an encapsulated HCl molecule in semiconducting carbon nanotube or in a BN nanotube. Depending on the initial orientation of the HCl molecule, the subsequent laser-induced dynamics is different: either complete disintegration or rebonding of the HCl molecule. Radial motion of the nanotube is always observed and a vacancy appears on the tube wall when the HCl is perpendicular to the tube axis. Those results are important to analyze confined nanochemistry and to manipulate molecules and nanostructures encapsulated in organic and inorganic nanotubes., Y.M. is supported by the Next Generation Supercomputing project conducted by MEXT Japan. H. Z. acknowledges financial support from the National Natural Science Foundation of China (NSFC, Grants No. 11074176 and No. 10676025), the NSAF (Grant No. 10976019), and the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20100181110080). A. R. acknowledges financial support from Spanish MEC (FIS2007-65702-C02-01), ACIPromociona (ACI2009-1036), ‘‘Grupos Consolidados UPV/EHU del Gobierno Vasco’’ (IT-319-07), the European Union through the FP7 e-I3 ETSF (Contract No. 211956), and THEMA (Contract No. 228539) projects.

The effect of growth hormone (GH) on immune function was studied using normal and hypophysectomised male Wistar rats. Hypophysectomy was performed by the auditory approach at 4 weeks of age. Normal and hypophysectomised rats were treated with saline or 0.4IU/body GH daily during 7 to 11 weeks of age. Histological features of the thymus and spleen and immunological parameters including blood cell counts, lymphocyte subsets, serum immunoglobulin levels, splenic natural killer activity, and mitogen-induced splenic lymphocyte proliferation were examined in the rats at 11 weeks of age. In hypophysectomised rats, the counts of peripheral white blood cells (5,513 +/- 813/microliters), lymphocytes (4,838 +/- 737/microliters), Th/i cells (2,237 +/- 329/microliters), and B cells (1,400 +/- 509/microliters), Th/i/Ts/c ratio (1.78 +/- 0.27), splenic T cell subsets (pan T: 51.0 +/- 4.3%, Th/i: 31.6 +/- 3.0%, Ts/c: 23.9 +/- 2.7%), and serum IgG level (2,148 +/- 470mg/l) were significantly decreased as compared with normal rats. Natural killer activity (17.8 +/- 4.6%) and mitogen-induced proliferation of T cells (Con A: 47.1 +/- 15.7, PHA: 51.6 +/- 12.5) were also suppressed. Hypoplasia of the thymus and spleen was observed in parallel to retarded growth of the rats. In contrast, GH supplement to the hypophysectomised rats resulted in increases in growth and lymphoid tissue, and the restoration of the counts of peripheral white blood cells (6,850 +/- 840/microliters), lymphocytes (6,211 +/- 731/microliters), Th/i cells (2,909 +/- 304/microliters), and B cells (1,947 +/- 402/microliters), Th/i/Ts/c ratio (2.04 +/- 0.34), serum IgG level (3,414 +/- 1,326mg/l), and natural killer activity (25.7 +/- 4.7%). However, splenic lymphocyte subsets and mitogen-induced proliferation of T cells were not recovered by GH treatment for 4 weeks. GH administered to normal rats increased serum IgG level (4,982 +/- 1,496mg/l) but did not affect other immunological parameters. These results indicate that humoral and cell-mediated immune function are impaired in hypophysectomised rats, but GH supplement administered to them restored most of the impaired immune function, suggesting that GH plays an important role in the development of immune function.

Combining time-dependent density functional calculations for electrons with molecular dynamics simulations for ions, we investigate the dynamics of excited carriers in a (3,3) carbon nanotube at different temperatures. Following an hν=6.8 eV photoexcitation, the carrier decay is initially dominated by efficient coupling to electronic degrees of freedom. At room temperature, the excitation gap is reduced to nearly half its initial value after ∼230 fs, where coupling to ionic motion starts dominating the decay. We show that the onset point and damping rate in the phonon regime change with initial ion velocities, a manifestation of temperature-dependent coupling between electronic and ionic degrees of freedom., A. R. was supported by the EC projects NANOQUANTA (No. NMP4-CT-2004-500198), SANES (No. NMP4-CT-2006-017310), Spanish MCyT, and the Humboldt Foundation. D. T. was supported by NSF NIRT Grants No. DMR-0103587, No. ECS-0506309, NSF NSEC Grant No. EEC-425826, and the Humboldt Foundation.

We propose to use photodesorption as a noninvasive tool to clean carbon nanotubes from oxygen, offering a clear advantage over thermal and chemical treatments. The detachment of chemisorbed oxygen from atomic vacancies is triggered by a resonant Auger process, initiated by an O1s→O2p transition, which leaves two holes in the O2s level. In the electronically excited state, oxygen desorbs spontaneously, with no damage to the carbon network or the cylindrical nanotube shape. Subsequent reaction of oxygen atoms with H2 molecules is shown to prevent reoxidation of the nanotube., A.R. acknowledges support from the European Community 6th framework Network of Excellence NANOQUANTA (NMP4-CT-2004-500198) Spanish MCyT and the University of the Basque Country. D.T. was partly supported by the NSF-NIRT Grant No. DMR-0103587.

We combined resonant photoabsorption and vibration spectroscopy with scanning tunneling microscopy (STM) to unambiguously identify the presence of Stone-Wales (SW) defects in carbon and boron nitride nanotubes. Based on extensive time-dependent ab initio density functional calculations, we propose to resonantly photoexcite SW defects in the infrared and ultraviolet regime as a means of their identification. Onset of nonradiative decay to a local defect vibration with a frequency of 1962 cm-1 serves as a fingerprint of such defects in carbon nanotubes. The bias dependence of the STM images shows distinct features associated with the presence of SW defects., Y.M. was supported by NAREGI Nanoscience Project, Ministry of Education, Culture, Sports, Science and Technology, Japan. A.R. acknowledges support from the EC grants (HPRN-CT-2000-00128 and HPRN-CT-2000-00167) and Spain MCyT. M.Y. and D.T. acknowledge partial support by NSF-NIRT grant DMR- 0103587.

We extend the time-dependent density functional formalism to study the microscopic response of defective nanotubes to electronic excitations. We find the lifetime of electronic excitations in these nanostructures to be several orders of magnitude longer than in solids, necessitating the use of excited-state molecular dynamics to correctly describe the atomic motion. We find that electronically excited nanotubes with monatomic vacancies show an unexpected self-healing ability, which is intimately linked to their nanometer size. © 2004 Elsevier B.V. All rights reserved., This work was performed under the management of the Frontier Carbon Technology supported by NEDO. D.T. and M.Y. acknowledge partial support by NSF-NIRT grant DMR-0103587. A.R. was supported by the European Community research and training network COMELCAN (HPRN-CT-2000- 00128), MCyT of Spain Grant MAT2001-09, and Basque Country University.

One of challenging application of carbon nanotubes is nano-scaled electronic device, in which precise control of defects and carriers is required in analogy of silicon-based technology. In this work, we show that optical excitations can be promising tools to analyze and control defects in nanotubes being alternative to conventional heattreatments. We performed ab initio calculations, which solve the time-dependent Schrodinger equations for electrons on real-time axis as well as classical Newton’s equations of motions for ions. This method is also useful to investigate carrier dynamics under finite temperatures. These works were done under collaboration with Prof. Angel Rubio, Prof. David Tomanek, Dr. Savas Berber, and Miss Mina Yoon.

Presentado al "Tsukuba Symposium on Carbon Nanotube" in commemoration of the 10th Anniversary of its discovery., Stability test of nanotubes with presence of single vacancies has been performed by means of tight-binding molecular dynamics and electron–ion dynamics within the framework of the density functional theory. A4Â diameter nanotube having a single vacancy with three dangling bonds has been found to retain its cylindrical shape under high temperature around 4000K, despite its large internal strain energy. Meanwhile, an electronic excitation of vacancy-related state has shown considerable atomic displacement, which may cause extraordinary large lattice vibration or nanotube decay. Furthermore, the single vacancy can stabilize itself by making carbon dimer to remain with only one dangling bond. Narrower nanotubes tend to prefer this self-stabilization and thus could be tolerant to the presence of defects

We demonstrate through extensive first-principles time-dependent density functional calculations that attractive van der Waals interaction between closed-shell atoms can be enhanced by light with constant spatial intensity. We illustrate this general phenomenon for a He dimer as a prototypical case of complex van der Waals interactions and show that when excited by light with a frequency close to the 1s → 2p He-atomic transition, an attractive force larger than 7 pN is produced. This force gain is manifested as a larger acceleration of He-He contraction under an optical field. The concerted dynamical motions of the He atoms together with polarity switching of the charge-induced dipole cause the contraction of the dimer. These findings are relevant for the photo-induced control of weakly bonded molecular species, either in gas phase or in solution., A.R. acknowledges financial support from the European Research Council Advanced Grant DYNamo (ERC-2010-AdG-267374), Spanish Grant (FIS2010-21282-C02-01), Grupos Consolidados del Gobierno Vasco (IT578-13), and European Commission project CRONOS (Grant No. 280879-2). H.Z. acknowledges financial support from the National Natural Science Foundation of China (NSFC Grant No. 11074176 and NSAF Grant No. 10976019) and support from the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20100181110080).

We report on a first-principles total-energy calculation that provides the energetics and electronic structure of stable polymerized fullerites consisting of the smallest fullerene ${\mathrm{C}}_{20}.$ We find that the ${\mathrm{C}}_{20}$ fullerene has periodic three-dimensional covalent networks with orthorhombic and tetragonal symmetries. Both are found to be energetically stable and to be elemental semiconductors with a moderate energy gap of about 1.5 eV. Substantially high peaks of the density of states are found to appear below the top of the valence band, suggesting that these materials under hole-doped conditions are candidates for superconductors.

Met-enkephalin concentration-dependently and transiently inhibited the ileal twitch contraction and this inhibition gradually recovered with time. Bacitracin, phosphoramidon, thiorphan and captopril did not influence the twitch inhibition of met-enkephalin, but bestatin increased the twitch inhibitory potency of met-enkephalin and terminated it in a manner which almost paralleled that of untreated tissue. Transient inhibition of twitch contraction after tetanic stimulation (post-tetanic twitch inhibition) was obtained. Bestatin increased the potency of met-enkephalin and this was terminated within 2 min. Phosphoramidon tended to increase the potency and delayed the termination of post-tetanic twitch inhibition. Bacitracin, thiorphan and captopril did not influence either the potency or the termination of post-tetanic twitch inhibition. Morphine-induced twitch inhibition was not influenced by bacitracin, bestatin or phosphoramidon. These results suggest that bestatin-sensitive aminopeptidase and phosphoramidon-sensitive enkephalinase take part in post-tetanic twitch inhibition, acting in a different mode of action, and have an important role in the termination of the pharmacological action of endogenous opioids (post-tetanic twitch inhibition) in MPLM. This different mode of response of bestatin and phosphoramidon upon post-tetanic twitch inhibition may underlie that aminopeptidase is a more soluble enzyme and enkephalinase is membrane-bound in myenteric plexus-longitudinal muscle (MPLM).