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Comet Interceptor (Comet-I), to be launched in 2029 as a piggyback to ESA's ARIEL mission, is aimed to perform the first fly-by of a pristine long-period comet. The mission will be composed of a main spacecraft, SC A (ESA), and two small probes to be released prior to the fly-by, SC B1 (JAXA) and SC B2 (ESA). This work analyzes the attitude performance of JAXA's 24U-sized spacecraft through the dust environment of a yet-to-be-discovered target comet. Main challenges to the mission are associated to the high levels of uncertainty and extremity of fly-by conditions: highly-active dust environment, uncertain fly-by altitude (750 ± 250 km (1σ), as of 2021), and large and unknown relative fly-by speeds (15–70 km/s). A Monte Carlo analysis is performed to characterize the effect of dust particle impacts on the attitude of SC B1, and to evaluate the likelihood of satisfying pointing and angular velocity requirements of the science camera. Analysis initially shows that particles of mass 10−8–10−5 kg represent the most relevant source of perturbation due to their transferred angular momentum and likelihood of being encountered, and saturation of reaction wheels is shown unlikely given the large fly-by speeds and short fly-by durations (20 min–2 h). More detailed analysis ultimately suggests a probability larger than 90% of satisfying science camera requirements despite the extreme, uncertain fly-by conditions, dust environment, and component inaccuracies (star tracker, gyroscopes, and reaction wheels). Results also show that upgrading the reaction wheel that is implemented along the camera line-of-sight can improve, but only marginally, attitude performance, and proper alignment of solar arrays parallel to the incoming flow of particles is shown essential to maximize probability of success. [ABSTRACT FROM AUTHOR]

Pressure, density, and temperature data for H2O were obtained up to 260 GPa by using laser-driven shock compression technique. The shock compression technique combined with the diamond anvil cell was used to assess the equation of state models for the P-ρ-T conditions for both the principal Hugoniot and the off-Hugoniot states. The contrast between the models allowed for a clear assessment of the equation of state models. Our P-ρ-T data totally agree with those of the model based on quantum molecular dynamics calculations. These facts indicate that this model is adopted as the standard for modeling interior structures of Neptune, Uranus, and exoplanets in the liquid phase in the multi-Mbar range. [ABSTRACT FROM AUTHOR]

Indirect laser-driven shockless compression experiments on gold targets were performed to characterize pressure loading processes and target states. Free surface velocities of the gold target under ramped pressure loading were measured using line-imaging velocity interferometers. From the velocity data and the equation of state, the maximum pressure and strain rate attained under compression were estimated to be ~50 GPa and ~4×107 s-1, respectively. Optical reflectivity was measured simultaneously with the velocity, the result suggesting no significant or unexpected temperature increases in the ultrafast shockless compression process. [ABSTRACT FROM AUTHOR]

When a laser is focused on an underwater object, it experiences a large amount of pressure owing to the plasma confinement effect of water. A hemispherical bubble is generated on the surface of the object, and large pressure is generated when the bubble collapses. In this study, we conducted experiments using different laser energies to analyze the pressure–time histories associated with bubble contraction. The maximum pressure was 10%–40% of the laser ablation pressure, whereas the pressure pulse width was 5–10 times longer than the laser pulse width. Furthermore, the bubble motion could be adiabatically explained, except for the plasma interaction region. The results indicate that the pressure at which the bubble collapses does not depend on the maximum size of the generated bubble but depends on the energy of water vapor within the bubble. [ABSTRACT FROM AUTHOR]

Two partially coherent light laser beams, coupled with a random phase plate were focused at an angle of 31.7° with the centers of the beams offset by 250 μm. This produced a relatively uniform (7% root-mean-square) irradiated spot of 400 μm. When this technique was used to produce a shock wave in a copper wedge, a relatively uniform shock of 2 ns duration was produced. In addition, a multilayered flyer plate was accelerated using this method to an average speed of 21 km/s and produced a planar impact on a glass window. It is anticipated that this technique can be used to produce important multi-Mbar equation of state information in future experiments. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Pressure, density, and temperature were measured along the principal Hugoniot of the Si-doped Glow Discharge Polymer used in Inertial Confinement Fusion (ICF) capsules up to 5 Mbar, covering conditions beyond the first shock in a full-scale Inertial Confinement Fusion (ICF) capsule. The experiments were performed using the GEKKOXII laser at the Institute of Laser Engineering at Osaka University in Japan. Results are in good agreement with predictions obtained from ab initio Hugoniot calculations, but softer than the quotidian equation of state average atom model. Ab initio calculations show that dissociation of carbon bonds need to be taken into account in order to explain Hugoniot compressibility. [ABSTRACT FROM AUTHOR]

Pressure, density, temperature, and reflectivity measurements along the principal Hugoniot of Ge-doped plastics used in Inertial Confinement Fusion capsules surrogates were obtained to pressures reaching up to 7 Mbar and compared to Quotidian Equation of State models. The experiment was performed using the GEKKO XII laser at the Institute of Laser Engineering at Osaka University in Japan. High precision measurements of pressure and density were obtained using a quartz standard and found to be in good agreement with theoretical Hugoniot curves. Modeling of reflectivity measurements show that shocked samples can be described as poor metals and that mean ionization calculated within the frame of QEOS is overestimated. Similarly, shock temperatures were found to be below theoretical Hugoniot curves. [ABSTRACT FROM AUTHOR]

Abstract: We have grown bi-layer InAs quantum dots (QDs) on GaAs substrates for extending the emission wavelength of InAs/GaAs QDs beyond 1.3μm. The QD bi-layer, which comprises two QDs layers (seed- and active-QDs) separated with a GaAs spacer layer of 10nm in thickness, exhibits light emission from active-QDs with longer wavelength. An enlargement of the active-QDs occurred by optimizing several growth parameters: growth temperature of seed-QDs, amount of InAs supplied for seed- and active-QDs layers. These optimized parameters lowered the density of the seed-QDs strain spreading upward, which resulted in an enlargement of the active-QDs. We achieved a control of the extension of emission wavelength up to approximately 1.4μm from 1.2μm. These results indicate that the QD bi-layer can be applied to a broadband light source exhibiting an emission spectrum centered at 1.3μm with a bandwidth of 200nm. [Copyright &y& Elsevier]

Background: Angiopoietin-like protein 4 (Angptl4) is thought to cause an increase in serum triglyceride levels. In the present study, we elucidated Angptl4 expression in the mouse models of type 1 and type 2 diabetes mellitus, and investigated the possible mechanisms involved. Methods: Type 1 diabetes was induced in C57BL/6 J mice by treating them with streptozotocin (STZ). Type 2 diabetes was induced by feeding the mice a high-fat diet (HFD) for 18 weeks. Results: The levels of Angptl4 mRNA expression in liver, white adipose tissue (WAT), and brown adipose tissue (BAT) were found to increase in the STZ diabetic mice relative to control mice. This eff ect was attenuated by insulin administration. In the HFD diabetic mice, the Angptl4 mRNA expression levels were increased in liver, WAT, and BAT. Treatment with metformin for 4 weeks attenuated the increased levels of Angptl4 mRNA. Fatty acids (FAs) such as palmitate and linoleate induced Angptl4 mRNA expression in H4IIE hepatoma cells and 3T3-L1 adipocytes. Treatment with insulin but not metformin attenuated FA-induced Angptl4 mRNA expression in H4IIE. Both insulin and metformin did not infl uence the eff ect of FAs in 3T3-L1 cells. Conclusion: These observations demonstrated that Angptl4 mRNA expression was increased through the elevated free FAs in diabetic mice. [ABSTRACT FROM AUTHOR]

Background: Angiopoietin-like protein 4 (Angptl4) is thought to cause an increase in serum triglyceride levels. In the present study, we elucidated Angptl4 expression in the mouse models of type 1 and type 2 diabetes mellitus, and investigated the possible mechanisms involved. Methods: Type 1 diabetes was induced in C57BL/6 J mice by treating them with streptozotocin (STZ). Type 2 diabetes was induced by feeding the mice a high-fat diet (HFD) for 18 weeks. Results: The levels of Angptl4 mRNA expression in liver, white adipose tissue (WAT), and brown adipose tissue (BAT) were found to increase in the STZ diabetic mice relative to control mice. This eff ect was attenuated by insulin administration. In the HFD diabetic mice, the Angptl4 mRNA expression levels were increased in liver, WAT, and BAT. Treatment with metformin for 4 weeks attenuated the increased levels of Angptl4 mRNA. Fatty acids (FAs) such as palmitate and linoleate induced Angptl4 mRNA expression in H4IIE hepatoma cells and 3T3-L1 adipocytes. Treatment with insulin but not metformin attenuated FA-induced Angptl4 mRNA expression in H4IIE. Both insulin and metformin did not influence the eff ect of FAs in 3T3-L1 cells. Conclusion: These observations demonstrated that Angptl4 mRNA expression was increased through the elevated free FAs in diabetic mice. [ABSTRACT FROM AUTHOR]

The principal Hugoniot for liquid hydrogen was obtained up to 55 GPa under laser-driven shock loading. The pressure and density of compressed hydrogen were determined by impedance matching to a quartz standard. The shock temperature was independently measured from the brightness of the shock front. Hugoniot data of hydrogen provide a good benchmark to modern theories of condensed matter. The initial number density of liquid hydrogen is lower than that for liquid deuterium, and this results in shock-compressed hydrogen having a higher compression and higher temperature than deuterium at the same shock pressure. [ABSTRACT FROM AUTHOR]

Laser shock compression experiments on precompressed samples offer the possibility to explore extreme material states unreachable by static or single-shock compression techniques alone. We have found significant increases in static compression pressure in a wide-opening and thin diamond precompression cell. This suggests that the precompression target is adaptable to advanced coupling techniques with laser-driven dynamic compression methods. The novel coupling techniques proposed give the potential to access outstanding material states required in planetary and condensed-matter physics. [ABSTRACT FROM AUTHOR]

The role of ion channels expressed in sensory neurons on mechanical and thermal hyperalgesia was examined in a rat model of cisplatin-induced peripheral neuropathy. The rats were injected with 3mg/kg of cisplatin intraperitoneally once per week for five consecutive weeks. The von Frey test, pin-prick test and plantar test were performed to examine any noxious sensitivity of the skin. The Randall-Selitto test of the gastrocnemius muscle (GM) and the measurement of grip forces were performed to quantify muscle hyperalgesia. Coordination/motor was assessed by Rota-rod testing. Expressions of the ion channels TRPV1, TRPV2, P2X(3) and ASIC3 were examined in dorsal root ganglion (DRG) neurons and the muscle afferent neurons innervating GM. Effects of antagonists against either P2X(3) or ASICs on behavioral responses were evaluated. Mechanical hyperalgesia and allodynia of both skin and muscle were observed in cisplatin-treated animals. Expressions of TRPV2, P2X(3), and ASIC3 increased in all DRG neurons. In addition, expressions of P2X(3) and ASIC3 also increased in muscle afferent neurons in DRGs. Antagonists against P2X(3,2/3) and ASICs showed a suppressive effect on both skin and muscle hyperalgesia induced by cisplatin administration. Upregulation of TRPV2, P2X(3), and ASIC3 may play important roles in the mechanical hyperalgesia induced by cisplatin. Furthermore, cisplatin treatment also induced muscle hyperalgesia in muscle afferent neurons in connection with the upregulation of P2X(3) and ASIC3. [ABSTRACT FROM AUTHOR]

Equation-of-state data, not only pressure and density but also temperature, for polystyrene (CH) are obtained up to 510 GPa. The region investigated in this work corresponds to an intermediate region, bridging a large gap between available gas-gun data below 60 GPa and laser shock data above 500 GPa. The Hugoniot parameters and shock temperature were simultaneously determined by using optical velocimeters and pyrometers as the diagnostic tools and the α-quartz as a new standard material. The CH Hugoniot obtained tends to become stiffer than a semiempirical chemical theoretical model predictions at ultrahigh pressures but is consistent with other models and available experimental data. [ABSTRACT FROM AUTHOR]

Abstract: The selective-area-growth (SAG) of InAs quantum dots (QDs) with different emission wavelengths on different areas was carried out using the metal-mask (MM) method during conventional molecular beam epitaxy (MBE) growth. Two SAG areas (SAG-1 and SAG-2) of the QDs were obtained using the rotational MM having square windows; first, the MM was mounted on a substrate for SAG-1, and then the same MM was used for SAG-2 after being rotated it by 180°. The absorption wavelengths of the selectively grown QDs were controlled by inserting strain-reducing layers of a different thickness on each grown QD layer. Photoluminescence measurements revealed the successful SAG of QDs in the neighboring a few hundred-micron-square areas with different emission wavelengths, e.g., 1250 and 1300nm. These techniques are promising for applications of QD-based optical and electronic devices, including our proposed photonic crystal (PC) and QD-based all-optical digital flip–flop (FF) device, i.e., PC-FF. [Copyright &y& Elsevier]

In order to consider the total atmospheric loadings of the PAHs (polycyclic aromatic hydrocarbons) from traffic activities, the emission factors of PAHs were estimated and from the obtained emission factors and vehicle transportation statistics, total atmospheric loadings were integrated and the loadings into the water body were estimated on a regional scale. The atmospheric concentration of PAHs was measured at the roadside of a road with heavy traffic in the Hiroshima area in Japan. The samplings were conducted in summer and winter. Atmospheric particulate matters (fine particle, 0.6-7 mm; coarse particle, over 7mm) and their PAH concentration were measured. Also, four major emission sources (gasoline and diesel vehicle emissions, tire and asphalt debris) were assumed for vehicle transportation activities, the chemical mass balance method was applied and the source partitioning at the roadside was estimated. Furthermore, the dispersion of atmospheric particles from the vehicles was modelled and the emission factors of the sources were determined by the comparison to the chemical mass balance results. Based on emission factors derived from the modelling, an atmospheric dispersion model of nationwide scale (National Institute of Advanced Industrial Science and Technology - Atmospheric Dispersion Model for Exposure and Risk assessment) was applied, and the atmospheric concentration and loading to the ground were calculated for the Hiroshima Bay watershed area. [ABSTRACT FROM AUTHOR]

Abstract: A metal-mask (MM) molecular beam epitaxy technique for selective-area-growth (SAG) of self-assembled InAs-quantum dots (QDs) on a GaAs substrate was developed for realizing ultra-small and ultra-fast all-optical switches (PC-SMZ). Growth conditions of the QD were optimized by virtue of the MM with a large window enabling real-time observations of reflection-high-energy-electron-diffraction patterns and growth temperatures. Successful SAG was confirmed by atomic force microscope observations of the high-density (4×1010 cm−2) QD grown only on the unmasked area, while high uniformity of the QD was examined by room-temperature photoluminescence (PL) measurement. It resulted in a 1250nm peak in the center wavelength, 38meV in FWHM, comparable to that of the QD grown without the MM. In addition, insertion of a strain-reducing layer of GaInAs on the QD reported previously was confirmed to be effective for controlling the PL peak wavelength of the QD between 1250 and 1320nm without degrading the optical quality of QDs. The MM method shown here provides a possibility of an advanced PC-SMZ, i.e., an ultra-fast all-optical flip-flop (PC-FF), which requires a QD ensemble with a different absorption-peak wavelength in a different area. [Copyright &y& Elsevier]

Recent investigations suggest that the AKT/glycogen synthase kinase 3 (GSK3) signaling cascade may be associated with the pathophysiology of schizophrenia and methamphetamine (METH) use disorder. One important molecule related to this cascade is β-arrestin 2 (ARRB2). We therefore conducted a genetic case–control association analysis of the gene for ARRB2 with schizophrenia and METH use disorder in a Japanese population (547 people with schizophrenia, 177 with METH use disorder and 546 controls). A possible association of ‘tag single nucleotide polymorphisms (SNPs)’ was found in METH use disorder (rs1045280: Pgenotype = 0.0118, Pallele = 0.00351; rs2036657: Pallele = 0.0431; rs4790694: Pgenotype = 0.0167, Pallele = 0.0202), but no association was found with schizophrenia. We also evaluated the gene–gene interactions among ARRB2, AKT1, and GSK3B, which we previously reported for each of these diseases. However, no interaction was seen in our samples. This is the first association analysis of ARRB2, and our results indicate that ARRB2 may play a role in the pathophysiology of METH use disorder. [ABSTRACT FROM AUTHOR]

The atmospheric concentration and dry and wet deposition were measured for particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) from August to December in Higashi-Hiroshima City Japan. PM concentration of fine particles (0.6-7 !m) was 5.7-75.1 µg m-3, and coarse particles (>7 µm) was 2.2-22.3 µg m-3. Total PAHs concentration of fine particles was 0.14-16.3 ng m-3, and coarse particles was 0.01 -0.77 ng m-3. Their concentration increased on non-rainy days and decreased rapidly on rainy days. For seasonal fluctuations of PAHs, their concentrations decreased from summer to winter, and the rate of decrease was more distinct for fine particles. For total (dry + wet) depositions, the PM flux was 1.9-11.2 mg m-2d-1, and the total PAHs flux wax 1.9-97.2 ng m-3d-1. From these measurements, the yearly total loading of PAHs was estimated for the particle phase. Total loading was 28 µg m-2 y-1 for the dry deposition and 52 mg m-2y-1 for the wet deposition. The loading of the wet deposition was comparable to those of the dry deposition for alt ring numbers. [ABSTRACT FROM AUTHOR]

Equation-of-state (EOS) measurements for polystyrene in TPa (10 Mbar) pressure regions are presented. Polystyrene Hugoniot data were obtained up to 2.7 TPa using impedance matching techniques with laser direct drive at the GEKKO/HIPER laser facility [N. Miyanaga et al., in Proceedings of the 18th International Conference on Fusion Energy (IAEA, Sorrento, Italy, 2001), IAEA-CN-77] The results were compared with theoretical models and previous experimental data and found to be in good agreement with the previous data obtained by different drive and diagnostic techniques. [ABSTRACT FROM AUTHOR]

The GEKKQ/HIPER-laser [N. Miyanaga et al., in Proceedings of the 18th International conference on Fusion Energy (IAEA, Sorrento, Italy, 2001), IAEA-CN-77] driven shock experiments were characterized in detail for studies on equation-of-state (EOS) at ultrahigh pressures. High-quality shock waves were produced with the bundled 9 laser beams optically smoothed by spectral dispersion technique and Kinoform phase plates. The laser beams were directly focused on targets at up to an intensity of 1014 W/cm² or higher with a wavelength of 351 nm and a duration of 2.5 ns. Key issues on dynamic EOS research; the spatial uniformity and temporal steadiness of shock wave were estimated, and the preheating problem was also investigated by measurements of the self-emission and reflectivity from target rear surface. The experimental and analytical methods were validated by using double-step targets consisting of two Hugoniot standard metals. Extreme pressures only accessed in nuclear explosion experiments were generated with reproducibility and good accuracy using the laser direct-drive experimental system, for Al, Cu, polystyrene, and Ta. It was indicated that new and reliable EOS data at the ultrahigh pressures could he provided for materials ranging from low to high initial density by the laser direct-drive experimental technique. [ABSTRACT FROM AUTHOR]

Rietveld refinement and extended X-ray absorption fine structure (EXAFS) analysis on the synchrotron radiation X-ray data of BaTiO3-based shell phase powder specimens with Ho and Mg co-dopants were carried out to obtain the knowledge on the occupation site and its quantitative occupancy fraction in BaTiO3 perovskite structure. Ho ions occupied preferentially A-site in BaTiO3 and the occupation ratio was same in any doped compositions. Ho-O atomic distance in A-site is increased with increasing Ho doping in contract to that in B-site. [ABSTRACT FROM AUTHOR]

Two common serotonin transporter (SERT) untranslated region gene variants have been intensively studied, but remain inconclusively linked to depression and other neuropsychiatric disorders. We now report an uncommon coding region SERT mutation, Ile425Val, in two unrelated families with OCD and other serotonin-related disorders. Six of the seven family members with this mutation had OCD (n=5) or obsessive-compulsive personality disorder (n=1) and some also met diagnostic criteria for multiple other disorders (Asperger's syndrome, social phobia, anorexia nervosa, tic disorder and alcohol and other substance abuse/dependence). The four most clinically affected individuals-the two probands and their two slbs-had the I425V SERT gene gain-of-function mutation and were also homozygous for 5'-UTR SERT gene variant with greater transcriptional efficacy.Molecular Psychiatry (2003) 8, 933-936. doi:10.1038/sj.mp.4001365 [ABSTRACT FROM AUTHOR]

Equation-of-state measurements for a polyimide are presented. High-power KrF laser and chemical explosive-driven experiments provided Hugoniot data on the polyimide up to about 65 GPa. Conventional reflected-light measurements in the explosive experiments and velocity interferometry measurements in the laser experiments were performed. From both laser and explosive results the change of Hugoniot was indicated at near 30 GPa. [ABSTRACT FROM AUTHOR]

Recent studies demonstrated that experimental ulcers are associated with changes in the properties of voltage-sensitive sodium currents in sensory neurons. We hypothesized that nerve growth factor (NGF) contributes to these changes. Gastric ulcers were induced by acetic acid injection into the walt of the rat stomach. NGF expression was determined by ELISA and immunohistochemically. Sensory neurons were labeled by injection of a retrograde tracer into the gastric wall Sodium currents were recorded in gastric sensory neurons from nodose and dorsal root ganglia cultured for 24 h in the presence of NGF or a neutralizing NGF antibody, respectively. Gastric ulcer formation caused a rise in NGF concentration within the gastric wall and an increase in NGF immunoreactivity. Exposure to NGF caused a significant increase in the TTX-resistant sodium current, whereas the TTX-sensitive sodium current remained unchanged. This was associated with an acceleration of the recovery from inactivation in spinal sensory neurons. Production and release of NGF in the gastric wall may contribute to sensitization of primary afferent neurons during gastric inflammation. [ABSTRACT FROM AUTHOR]

We present the chemical bonding and electronic properties of liquid methane at temperatures from 2000 to 4000 K and high densities of up to 3.0 g/cm3, calculated using ab initio molecular dynamics simulations in combination with the Mulliken population analysis. Bond-overlap populations and pair distribution functions are studied to investigate the evolution of electron delocalization accompanying atomic structure change as the density is increased. In addition, we also investigated the bandgap energy, electronic density of states, and spatial distribution of electron density. We observed that molecular hydrogen and C‒C bonds are formed after methane dissociates, and then the system undergoes a nonmetal–metal transition coinciding with hydrogen being transformed from the molecular to the atomic state. The C‒C bonds in the system retain covalent character, even at the highest density of 3.0 g/cm3. [ABSTRACT FROM AUTHOR]

In situ femtosecond x-ray diffraction measurements and ab initio molecular dynamics simulations were performed to study the liquid structure of tantalum shock released from several hundred gigapascals (GPa) on the nanosecond timescale. The results show that the internal negative pressure applied to the liquid tantalum reached -5.6 (0.8)GPa, suggesting the existence of a liquid-gas mixing state due to cavitation. This is the first direct evidence to prove the classical nucleation theory which predicts that liquids with high surface tension can support GPa regime tensile stress. [ABSTRACT FROM AUTHOR]

Abstract: Multi-color quantum dot (QD) ensembles were grown by selective-area growth method to realize a shape-controlled broadband light source. By using a metal-mask, QD ensembles and strain reducing layer (SRL) were formed in selective areas on a wafer. The SRL thickness was varied to achieve appropriate shifts in the peak wavelength of the QD emission spectrum up to 90nm. A summation of PL spectra obtained from the multi-color QD ensembles shows a broadband emission spectrum with a width of approximately 120nm, even though this spectrum is attributed to the ground state emissions of these QD ensembles. A current-induced broadband light source such as a superluminescent diode (SLD) based on the multi-color QD ensembles is expected to have an emission spectrum with a width of more than 120nm owing to the combination of excited state emissions. Furthermore, a desired shape of the SLD spectrum can be obtained by controlling the injection current applied to each QD ensemble. This approach is promising for a shape-controlled broadband SLD, and it is particularly applicable to optical coherence tomography (OCT). [Copyright &y& Elsevier]

Abstract: We have developed a nanoprobe-assisted bottom-up technique that allows to fabricate site-controlled quantum dots (SC-QDs), using a specially designed atomic force microscope probe, referred to as the Nano-Jet Probe (NJP). Beginning with the fabrication of regular QD arrays by using the NJP, we vertically aligned self-assembled InAs QDs using the strain-induced stacking method and produced assembled QD stacks. In order to improve the optical property of the SC-QDs, an AlGaAs barrier layer was introduced in the spacer layer of the stacked structures. The photoluminescence measurements of the fabricated structures revealed that they had good crystallographic qualities. [Copyright &y& Elsevier]

Electric and magnetic properties were investigated on p-type Zn1-xCrxTe doped with nitrogen (N) as an acceptor. Thin films of p-Zn1-xCrxTe (x≤=0.09) were grown by molecular-beam epitaxy with the supply of N2 gas excited by rf plasma. With the increase of Cr composition x at an almost fixed N concentration of the order of 1020 cm-3, the temperature dependence of resistivity changed from metallic behavior to an insulating one, accompanied with a significant decrease of the hole concentration. The magnetization measurements revealed that ferromagnetic behaviors observed in undoped Zn1-xCrxTe were suppressed due to the nitrogen doping; with N concentrations of the order of 1020 cm-3, hysteresis loops in the magnetization curve disappeared, the magnitude of magnetization decreased, and the ferromagnetic transition were not observed down to 2 K according to the Arrott plot analysis. These experimental findings are discussed on the basis of the ferromagnetic double exchange interaction which is considered to work on the Cr 3d impurity level formed in the band gap of ZnTe. [ABSTRACT FROM AUTHOR]

Several different lines of evidence suggest that genes involved in serotonergic neurotransmission are factors in the pathogenesis of schizophrenia. For example, 5HT[sub 5A] knockout mice revealed decreased locomotor response to lysergic diethylamide (LSD), which produces a psychotic-like state in healthy people. Recently, we reported a naturally occurring conservative Pro15Ser substitution in the 5-HT[sub 5A] receptor. Here, we evaluate whether this substitution is associated with schizophrenia in a sample including 249 unrelated Japanese schizophrenia patients and 253 unrelated controls. Patients and controls were genotyped for the Pro15Ser polymorphism by a PCR-RFLP assay. Ser15 allele frequencies were 0.07 in patients with schizophrenia and 0.02 in controls (x² = 17.42, df = 1, P < 0.0001). Thus, we detected a highly significant association of Pro15Ser to schizophrenia in a large population of Japanese schizophrenia patients and controls. Since case-control studies have an inherent potential for false-positive results due to population stratification, this finding is preliminary pending further studies, including studies using the transmission/disequilibrium test to eliminate stratification bias or control loci to assess ethnic matching of cases and controls. [ABSTRACT FROM AUTHOR]

We present an indirect method of estimating the strength of a shock wave, allowing on line monitoring of its reproducibility in each laser shot. This method is based on a shot-to-shot measurement of the X-ray emission from the ablated plasma by a high resolution, spatially resolved focusing spectrometer. An optical pump laser with energy of 1.0 J and pulse duration of ∼660 ps was used to irradiate solid targets or foils with various thicknesses containing Oxygen, Aluminum, Iron, and Tantalum. The high sensitivity and resolving power of the X-ray spectrometer allowed spectra to be obtained on each laser shot and to control fluctuations of the spectral intensity emitted by different plasmas with an accuracy of ∼2%, implying an accuracy in the derived electron plasma temperature of 5%-10% in pump-probe high energy density science experiments. At nano- and sub-nanosecond duration of laser pulse with relatively low laser intensities and ratio Z/A∼0.5, the electron temperature follows Te∼Ilas2/3. Thus, measurements of the electron plasma temperature allow indirect estimation of the laser flux on the target and control its shot-to-shot fluctuation. Knowing the laser flux intensity and its fluctuation gives us the possibility of monitoring shot-to-shot reproducibility of shock wave strength generation with high accuracy. [ABSTRACT FROM AUTHOR]

Ultrahigh-energy density (UHED) states greater than 1 Gbar pressure are typically observed under extreme conditions, such as in the core of an inertial confinement fusion implosion. A novel alternative approach for generating volumetric UHED states is to use nanowire arrays irradiated with a femtosecond ultrahigh-intensity laser. In this paper, we present an experimental investigation on laser absorption and energy transport in nanowire arrays irradiated with a picosecond kilojoule petawatt laser. The laser–target interactions were studied by measuring the x-ray emission and escaping hot electrons from a bare Cu foil and a foil with a nanowire array grown on its surface. The measured Cu-Kα and He-α emissions from the nanowire array were higher than those from the flat foil. In addition, hot electrons observed from the front surface of the nanowire array were enhanced. On the other hand, despite the stronger Kα emission from the nanowire array and the enhancement of hot electrons escaping from the front surface of the nanowire array, the number of hot electrons observed from the rear side of the flat foil target was slightly lower than that of the flat foil. A comparison of the experimental results with the results of a two-dimensional particle-in-cell simulation code suggested that the magnetic fields generated around the periodic nanowire array trap hot electrons, improving the electron-to-target energy coupling and efficiently producing UHED states. [ABSTRACT FROM AUTHOR]

A two-dimensional cyanide-bridged Co–W bimetal assembly, (H5O2+)[Co(4-bromopyridine)2{W(CN)8}], was prepared. A synchrotron radiation (SR) X-ray single-crystal measurement shows that the crystal structure is monoclinic in the P21/c space group. Magnetic and spectroscopic measurements show that this assembly takes CoIIIlow-spin(S = 0)–WIV(S = 0) in the temperature range of 2–390 K. Such a wide temperature range CoIIIlow-spin–WIV phase has not been reported so far. First-principles calculations show that the band gap is composed of a WIV valence band and a CoIII conduction band. 785 nm light irradiation causes photo-induced magnetization with a Curie temperature of 27 K and a coercive field of 2000 Oe. The crystal structure of the photo-induced phase was determined to have larger lattice constants in the two-dimensional layer (bc-plane) by 3% compared to the original phase, which is due to the expansion of the distance of Co–N. The photo-induced phase returns to the original phase upon thermal treatment. First-principles calculations, and magnetic, and optical measurements prove that this photomagnetism is caused by the optical charge-transfer-induced spin transition from CoIIIlow-spin(S = 0)–WIV(S = 0) to CoIIhigh-spin(S = 3/2)–WV(S = 1/2). [ABSTRACT FROM AUTHOR]

Laser--plasma interaction and hot electrons have been characterized in detail in laser irradiation conditions relevant for direct-drive inertial confinement fusion. The experiment was carried out at the Gekko XII laser facility in multibeam planar target geometry at an intensity of approximately 3x1015 W/cm². Experimental data suggest that high-energy electrons, with temperatures of 20-50 keV and conversion efficiencies ofη<1%, were mainly produced by the damping of electron plasma waves driven by two-plasmon decay (TPD). Stimulated Raman scattering (SRS) is observed in a near-threshold growth regime, producing a reflectivity of approximately 0.01%, and is well described by an analytical model accounting for the convective growth in independent speckles. The experiment reveals that both TPD and SRS are collectively driven by multiple beams, resulting in a more vigorous growth than that driven by single-beam laser intensity. [ABSTRACT FROM AUTHOR]

Presents a diagrammatic image which states that serotonin transporter missense mutation is associated with a complex neuropsychiatric phenotype.

The development of small sized laser operating above room temperature is important in the realization of optical integrated circuits. Recently, micro-lasers consisting of photonic crystals (PhCs) and whispering gallery mode cavities have been demonstrated. Optically pumped laser devices could be easily designed using photonic crystal-slab waveguides (PhC-WGs) with an air-bridge type structure. In this study, we observe lasing at 1.3μm from two-photon pumped InAs-quantum-dots embedded GaAs PhC-WGs above room temperature. This type of compact laser shows promise as a new light source in ultra-compact photonics integrated circuits. [ABSTRACT FROM AUTHOR]

Plastic materials (CH) doped with mid-Z elements are used as ablators in inertial confinement fusion (ICF) capsules and in their surrogates. Hugoniot equation of state (EOS) and electronic properties of CH doped with germanium (at 2.5% and 13% dopant fractions) are investigated experimentally up to 7 Mbar using velocity and reflectivity measurements of shock fronts on the GEKKO laser at Osaka University. Reflectivity and temperature measurements were updated using a quartz standard. Shocked quartz reflectivity was measured at 532 and 1064 nm. Theoretical investigation of shock pressure and reflectivity was then carried out by ab initio simulations using the quantum molecular dynamics (QMD) code abinit and compared with tabulated average atom EOS models. We find that shock states calculated by QMD are in better agreement with experimental data than EOS models because of a more accurate description of ionic structure. We finally discuss electronic properties by comparing reflectivity data to a semiconductor gap closure model and to QMD simulations. [ABSTRACT FROM AUTHOR]

Using a hydrogen-terminated Si {111} surface as a substrate, we have grown Si nanowhiskers along the [112] direction by the vapor–liquid–solid mechanism. The minimum silicon core diameter was 3 nm and the maximum length was about 2 μm. The minimum silicon core diameter is close to the critical value for visible light emission due to the quantum confinement effect. In contrast to an oxidized Si surface, the hydrogen-terminated surface facilitates the formation of small molten Au–Si catalysts at a lower temperature (500 °C) which is slightly above the eutectic temperature. The formation of catalysts and the subsequent growth at the low temperature yield thin Si nanowhiskers on a Si substrate. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Magnetic reconnection is a universal process in space, astrophysical, and laboratory plasmas. It alters magnetic field topology and results in energy release to the plasma. Here we report the experimental results of a pure electron outflow in magnetic reconnection, which is not accompanied with ion flows. By controlling an applied magnetic field in a laser produced plasma, we have constructed an experiment that magnetizes the electrons but not the ions. This allows us to isolate the electron dynamics from the ions. Collective Thomson scattering measurements reveal the electron Alfvénic outflow without ion outflow. The resultant plasmoid and whistler waves are observed with the magnetic induction probe measurements. We observe the unique features of electron-scale magnetic reconnection simultaneously in laser produced plasmas, including global structures, local plasma parameters, magnetic field, and waves. [ABSTRACT FROM AUTHOR]

The shock ignition (SI) approach to inertial confinement fusion is a promising scheme for achieving energy production by nuclear fusion. SI relies on using a high intensity laser pulse (≈1016 W/cm2, with a duration of several hundred ps) at the end of the fuel compression stage. However, during laser–plasma interaction (LPI), several parametric instabilities, such as stimulated Raman scattering and two plasmon decay, nonlinearly generate hot electrons (HEs). The whole behavior of HE under SI conditions, including their generation, transport, and final absorption, is still unclear and needs further experimental investigation. This paper focuses on the development of an experimental platform for SI-related experiments, which simultaneously makes use of multiple diagnostics to characterize LPI and HE generation, transport, and energy deposition. Such diagnostics include optical spectrometers, streaked optical shadowgraph, an x-ray pinhole camera, a two-dimensional x-ray imager, a Cu Kα line spectrometer, two hot-electron spectrometers, a hard x-ray (bremsstrahlung) detector, and a streaked optical pyrometer. Diagnostics successfully operated simultaneously in single-shot mode, revealing the features of HEs under SI-relevant conditions. [ABSTRACT FROM AUTHOR]

Abstract: Two types of nanophotonic technologies—two-dimensional photonic crystal (2D PC) slab waveguides (WGs) and quantum dots (QDs)—were developed for key photonic device structures in the future. For an ultrafast digital photonic network, an ultrasmall and ultrafast symmetrical Mach–Zehnder (SMZ)-type all-optical switch (PC-SMZ) and an optical flip–flop device (PC-FF) have been developed. To realize these devices, one method is to develop a selective-area molecular beam epitaxial growth QD technique by employing a metal mask method. Another method is to establish a new design method, i.e., topology optimization of the 2DPC WG with a wide and flat bandwidth, high transmittance, and low reflectivity. We also fabricated an optical microcavity in a photonic crystal slab embedded with GaAs QDs by droplet epitaxy. The Purcell effect on the exciton emission of GaAs QDs was confirmed by microphotoluminescence and lifetime measurements. [Copyright &y& Elsevier]

Abstract: We have demonstrated the selective area growth of high density InAs quantum dots (QDs) by using site-controlled InAs dots that were formed in the desired regions as templates. The fabrication of the InAs dots for the templates was enabled by the use of a specially designed atomic-force-microscope (AFM) cantilever, referred to as the nano-jet probe (NJP). Using the NJP, two-dimensional (2D) arrays of ordered In nano-dots were reproducibly fabricated in the desired regions on a GaAs substrate. These In nano-dots were directly converted to InAs QD arrays by subsequent annealing with irradiation of arsenic flux. By using the converted QD arrays as strain templates, self-organized InAs QDs were formed in the selected regions. [Copyright &y& Elsevier]

Macrophages/monocytes and the proinflammatory mediators, such as tumour necrosis factor (TNF)-α, prostaglandin E2 (PGE2), macrophage inflammatory protein (MIP)-1α and MIP-1α, play a critical role in the progression of immunological disorders including rheumatoid arthritis, Behçet’s disease and Crohn’s disease. In addition, the nicotinic acetylcholine receptor-α7 (α7nAChR) subunit is an essential regulator of inflammation. In this study, we evaluated the expression of the α7nAChR subunit on human peripheral monocytes and the effect of nicotine on the production of these proinflammatory mediators by activated monocytes. Fluorescein isothiocyanate (FITC)-labelled α-bungarotoxin demonstrated the cell surface expression of the α7nAchR subunit. Pretreatment with low-dose nicotine caused inhibition of TNF-α, PGE2, MIP-1α and MIP-1α production, and mRNA expression of TNF-α, MIP-1α and MIP-1α and COX-2 in lipopolysaccharide (LPS)-activated monocytes. These suppressive effects of nicotine were caused at the transcriptional level and were mediated through α7nAChR. Nicotine suppressed the phosphorylation of I-κB, and then inhibited the transcriptional activity of nuclear factor-κB. These immunosuppressive effects of nicotine may contribute to the regulation of some immune diseases. [ABSTRACT FROM AUTHOR]

Abstract: In this study, three methods (bucket, plate for downward flux and upward flux, and water vessel) were used to measure atmospheric dry deposition fluxes at three different heights (0.5, 1.5 and 12.5m) to estimate the deposition fluxes of mass and polycyclic aromatic hydrocarbons (PAHs) in TERC (Tsukuba), Japan. Ambient particles were also collected using a high-volume air sampler, and ambient particle size distributions between 0.01 and 13.1μm were measured using a low-pressure cascade impactor to characterize the PAH levels and dry deposition. Settling velocities were calculated as the settling fluxes divided by the corresponding average ambient particle concentrations. In this research work, ‘we describe how small particles dominate atmospheric dry deposition of PAHs and how bucket deposition fluxes and net (downward minus upward) fluxes decrease with height due to resuspension and/or vertical distribution of suspended particles’ etc. [Copyright &y& Elsevier]

Summary. Two research groups have thus far reported a significant association between schizophrenia and a promoter polymorphism (-308G > A) of the gene encoding tumor necrosis factor alpha (TNF-α), while contradictive negative results have also been reported. We examined the possible association in a Japanese sample of 297 schizophrenia cases and 458 controls. Allele frequencies of both the patients and controls were very low (1.5% and 0.8%, respectively), and the difference was not statistically significant. We conclude that the effect of the -308G > A polymorphism on the development of schizophrenia is, if any, weak and the majority of Japanese schizophrenics are unrelated to the -308G > A polymorphism of the TNF-α gene. [ABSTRACT FROM AUTHOR]