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  • 1
    Electronic Resource
    Electronic Resource
    Construction and performance of beamline NE1B for circularly polarized soft x rays in the TRISTAN accumulation ring : Proceedings of the 5th international conference on synchrotron radiation instrumentation (1995)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 1696-1698 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Beamline BL-NE1B has been constructed at the 6.5-GeV TRISTAN accumulation ring (AR) for applications of circular polarization in the soft x-ray region. Circularly polarized soft x rays are produced by a helical undulator operation mode of an insertion device, EMPW#NE1. The fundamental harmonic peak can be tuned from 0.25 to 2 keV. The NE1B beamline is equipped with a vertical-dispersion spherical-grating monochromator using the Rowland mounting. A monochromatized circularly polarized photon flux higher than ∼1011 photons/s has been obtained over an energy range from 0.25 to 1.25 keV with an energy resolution (E/ΔE) of around 1500–300. An energy resolution of about 5000 has been achieved at 400 eV with slit widths of 10 and 10 μm. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1145887
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  • 2
    Electronic Resource
    Electronic Resource
    C lattice site distributions in metastable Ge1−yCy alloys grown on Ge(001) by molecular-beam epitaxy (2002)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 3644-3652 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Epitaxial metastable Ge1−yCy alloy layers with y≤0.045 were grown on Ge(001) by solid-source molecular-beam epitaxy (MBE) at temperatures Ts=200–400 °C. Using calculated strain coefficients and measured layer strains obtained from high-resolution reciprocal lattice maps (HR-RLMs), we determine C lattice site distributions as a function of Ts and total C concentration y. HR-RLMs show that all as-deposited alloys are fully coherent with their substrates. Ge1−yCy(001) layers grown at Ts≤350 °C are in a state of in-plane tension and contain C in substitutional sites, giving rise to tensile strain, as well as in nanocluster sites which induce negligible lattice strain. Ts=400 °C layers are strain neutral with negligible substitutional C incorporation. Increasing y and/or Ts leads to a decrease in substitutional C concentration, consistent with Raman spectroscopy results, with a corresponding increase in the C fraction incorporated in nanocluster sites. The latter suggests that nanocluster formation is kinetically limited during film deposition by the C–C adatom encounter probability at the growth surface. Overall, the results show that it is not possible by MBE to obtain fully substitutional C incorporation in Ge1−yCy(001) alloys, irrespective of y and Ts. This is consistent with ab initio density functional calculations results showing that C incorporation in nanoclusters sites is energetically favored over incorporation in substitutional Ge lattice sites. Annealing the Ge1−yCy(001) layers at Ta=550 °C leads to a significant decrease in the substitutional C fraction and, hence, lower tensile strain. Layers annealed at 650 °C are strain free as all substitutional C has migrated to lower-energy nanocluster sites. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1448677
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  • 3
    Electronic Resource
    Electronic Resource
    Carbon incorporation pathways and lattice sites in Si1−yCy alloys grown on Si(001) by molecular-beam epitaxy (2002)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 5716-5727 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We use a combination of in situ and postdeposition experimental probes together with ab initio calculations of strain coefficients and formation energies associated with specific C configurations in the Si lattice to determine C incorporation pathways and lattice site distributions in fully coherent Si1−yCy alloy layers grown by molecular-beam epitaxy on Si(001) as a function of deposition temperature Ts (380 °C–680 °C) and C fraction y (0–0.026). Lattice strain and Raman spectroscopy measurements demonstrate that all C, irrespective of y, is incorporated into substitutional lattice sites in Si1−yCy(001) layers grown at Ts≤480 °C. Increasing Ts≥580 °C leads to strong C surface segregation, as shown by in situ angle-resolved x-ray photoelectron spectroscopy, yielding additional pathways for C incorporation. Photoluminescence measurements indicate that an increasing fraction of the incorporated C in the higher-temperature layers resides in dicarbon complexes. Reflection high-energy electron diffraction and cross sectional transmission electron microscopy reveal surface roughening at Ts≥580 °C with the formation of bulk planar structures, interconnected by {113} segments, that are periodic along [001] with a periodicity which decreases with increasing Ts. We interpret the planar structures as layers of C-rich Si1−yCy which form in the presence of excess surface C resulting from segregation. Our ab initio density functional calculations show that substitutional C arranged in an ordered Si4C phase is 0.34 eV per C atom more stable than isolated substitutional C atoms. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1465122
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  • 4
    Electronic Resource
    Electronic Resource
    Bunch stability during high-gradient wakefield generation in a dielectric-lined waveguide : The 42nd annual meeting of the division of plasma physics of the American Physical Society and the 10th international congress on plasma physics (2001)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 8 (2001), S. 2461-2465 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A recently developed analytic theory for wakefields generated when a charge bunch, or train of bunches, passes along a dielectric-lined waveguide is applied to examine stability issues for this system. Such a configuration could be the key element in a two-beam accelerator to create colliding TeV-range electron and positron beams. It is shown that a 587 MV/m peak acceleration gradient can be achieved when a train of five 2 nC, 1.0 GeV, 0.20 mm long drive bunches passes along the axis of an alumina-lined waveguide (ε=9.5) with inner and outer radii 0.50 and 5.0 mm. The energy gain of a 0.2 nC test bunch in a 4 m long stage under these conditions is shown to be 1.48 GeV, for an average acceleration gradient of 370 MV/m. However, when a drive bunch is injected parallel to, but displaced from, the waveguide axis, transverse (mainly dipole) forces cause the tail of the bunch to swerve sharply toward the waveguide wall (head-to-tail instability), and to intersect the wall after traversing a relatively short distance. These results suggest that successful exploitation of the appealing strong wakefields generated by a train of drive bunches will require some means of transverse stabilization, such as an array of externally applied focusing and defocusing quadrupoles. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1343886
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  • 5
    Electronic Resource
    Electronic Resource
    Si(001):B gas-source molecular-beam epitaxy: Boron surface segregation and its effect on film growth kinetics (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 82 (1997), S. 2288-2297 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: B-doped Si(001) films, with concentrations CB up to 1.7×1022 cm−3, were grown by gas-source molecular-beam epitaxy from Si2H6 and B2H6 at Ts=500–800 °C. D2 temperature-programed desorption (TPD) spectra were then used to determine B coverages θB as a function of CB and Ts. In these measurements, as-deposited films were flash heated to desorb surface hydrogen, cooled, and exposed to atomic deuterium until saturation coverage. Strong B surface segregation was observed with surface-to-bulk B concentration ratios ranging up to 1200. TPD spectra exhibited β2 and β1 peaks associated with dideuteride and monodeuteride desorption as well as lower-temperature B-induced peaks β2* and β1*. Increasing θB increased the area under β2* and β1* at the expense of β2 and β1 and decreased the total D coverage θD. The TPD results were used to determine the B segregation enthalpy, −0.53 eV, and to explain and model the effects of high B coverages on Si(001) growth kinetics. Film deposition rates R increase by ≥50% with increasing CB〉˜1×1019 cm−3 at Ts≤550 °C, due primarily to increased H desorption rates from B-backbonded Si adatoms, and decrease by corresponding amounts at Ts≥600 °C due to decreased adsorption site densities. At Ts≥700 °C, high B coverages also induce {113} facetting. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.366036
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  • 6
    Electronic Resource
    Electronic Resource
    Effects of B doping on hydrogen desorption from Si(001) during gas-source molecular-beam epitaxy from Si2H6 and B2H6 (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 69 (1996), S. 3869-3871 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Boron doping concentrations (approximately-greater-than)6×1019 cm−3 were found to increase Si(001) growth rates RSi at low temperatures while decreasing RSi at higher temperatures during gas-source molecular beam epitaxy (GS-MBE) from Si2H6 and B2H6. In order to probe the mechanisms governing these effects, Si(001) samples with B coverages θB ranging from 〈0.05 to (approximately-equal-to)0.5 ML were prepared by exposing clean Si(001)2×1 wafers to B2H6 doses between 2×1017 and 4×1020 cm−2 at 200–400 °C. The samples were then heated to 700 °C to desorb the hydrogen, cooled to 200 °C, and exposed to atomic deuterium until saturation coverage. D2 temperature programmed desorption spectra exhibit β2 and β1 peaks due to dideuteride and monodeuteride desorption at 405 and 515 °C as well as new B-induced peaks, β2* and β1*, at 330 and 470 °C. Increasing θB increases the area under β2* and β1* at the expense of β2 and β1. Moreover, the total D coverage continuously decreases from (approximately-equal-to)1.23 ML in the absence of B to (approximately-equal-to)0.74 ML at θB=0.5 ML. We propose that the observed B-induced decrease in the Si*-D bond strength, where Si* represents surface Si atoms bonded to second-layer B atoms, is due to charge transfer and increased Si* dimer strain. The Si* to B charge transfer also deactivates Si surface dangling bonds causing the decrease in θD. These results are used to explain the GS-MBE growth kinetics. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.117132
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  • 7
    Electronic Resource
    Electronic Resource
    Rubbed polyimide films studied by scanning force microscopy (1995)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 66 (1995), S. 2218-2219 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The surfaces of rubbed polyimide films for aligning liquid crystal have been studied by atomic force microscopy. The unrubbed films consisted of randomly distributed polyimide clusters of different sizes. On the rubbed surface, however, the clusters are aligned in long chains along the rubbing direction. The cluster chains were separated by about 100 nm for small rubbing strength. For higher strength the cluster chains coalesced into wider ones. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.113172
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  • 8
    Electronic Resource
    Electronic Resource
    The effects of apigenin-7-O-β-d-glucuronopyranoside on reflux oesophagitis and gastritis in rats (2005)
    Oxford, UK : Blackwell Science Ltd
    Autonomic & autacoid pharmacology 25 (2005), S. 0 
    Details
    ISSN: 1474-8673
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Chemistry and Pharmacology , Medicine
    Notes: 1 This study evaluated the inhibitory action of apigenin-7-O-β-d-glucuronopyranoside (AGC), apigenin, and omeprazole on reflux oesophagitis and gastritis in rats. AGC was isolated from Clerodendron trichotomum leaves. 2 Oesophagitis and gastritis were induced by surgical procedure and the administration of indomethacin, respectively. The intraduodenal (i.d.) administration of AGC decreased the volume of gastric juice and increased the gastric pH compared with apigenin and omeprazole. The acid output was more inhibited by AGC in a dose-dependent manner than by apigenin and omeprazole. Compared with apigenin and omeprazole, AGC significantly decreased the size of gastric lesions, which were induced by exposure of the gastric mucosa to indomethacin. 3 Malondialdehyde (MDA) content, which is the end product of lipid peroxidation, was increased significantly after the induction of reflux oesophagitis. The MDA content was decreased by AGC (i.d. 3 mg kg−1), but not by either apigenin or omeprazole. This suggests that AGC has an antioxidative effect. In the oesophagitis group, the mucosal levels of glutathione (GSH) were significantly lower than that in the normal group. However, the GSH levels were preserved after administering the AGC, suggesting that AGC possesses scavenging activity. 4 In summary, AGC is more potent than apigenin and omeprazole at inhibiting reflux oesophagitis and gastritis and may therefore be a promising drug for their treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1474-8673.2005.00332.x
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  • 9
    Electronic Resource
    Electronic Resource
    Expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in human crescentic glomerulonephritis (2002)
    Oxford, UK : Blackwell Science Ltd
    Histopathology 41 (2002), S. 0 
    Details
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in human crescentic glomerulonephritisAims:  In glomerulonephritis, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) may play important roles in the formation of crescents. These studies are designed to evaluate the expression patterns of ICAM-1 and VCAM-1 in human crescentic glomerulonephritis and to determine the cellular origin of adhesion molecules in the crescentic lesions.Methods and results:  We examined the expression of ICAM-1 and VCAM-1 proteins in renal biopsies with cellular (n=7), fibrocellular (n=9) or fibrous (n=4) crescentic glomerulonephritis, and six controls by immunohistochemistry. mRNA expression of ICAM-1 and VCAM-1 was further evaluated by RNA in-situ hybridization. Cytokeratin or CD68 immunohistochemistry was performed on the same sections, where in-situ hybridization had been carried out. In cellular crescents, ICAM-1 and VCAM-1 proteins were over-expressed to a similar extent. Of the three types of crescents, the extent of ICAM-1 immunopositivity was the greatest in the cellular crescents and decreased towards the fibrous crescents (P 〈 0.05). Yet the extent of VCAM-1 immunoreactivity was not different between the types. Fibrous crescents still contained some epithelial cells and showed only VCAM-1 expression. In the glomeruli with cellular or fibrocellular crescents, the extent of ICAM-1 immunopositivity in the glomerular tufts was significantly larger than that of VCAM-1 (P 〈 0.05). In an in-situ hybridization study, the mRNA expression patterns of ICAM-1 and VCAM-1 paralleled their protein expressions. A double-labelling study showed that the signal for ICAM-1 and VCAM-1 mRNAs was mainly present in cytokeratin-positive and CD68-negative cells in the crescentic lesions.Conclusions:  These results suggest that glomerular parietal epithelial cells in cellular crescents up-regulate both ICAM-1 and VCAM-1, and that some epithelial cells retained in fibrous crescents persistently over-express VCAM-1, but not ICAM-1. They also suggest that ICAM-1 is involved in early leucocyte recruitment into glomeruli in crescentic glomerulonephritis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2559.2002.01446.x
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  • 10
    Electronic Resource
    Electronic Resource
    Enhanced cough response to hyperpnea with cold air challenge in chronic cough patients showing increased cough sensitivity to inhaled capsaicin (2003)
    Oxford, UK : Munksgaard International Publishers
    Allergy 58 (2003), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: Although many chronic cough patients have complained of an induced cough by cold air contact, the clinical relevance of cold air to inducing a cough and the diagnostic value of a hyperpnea with cold air (HCA) challenge to detect a hyperreactive cough reflex have not yet been investigated.Methods: Recordings of cough counts after a 2-min HCA challenge were performed in 49 chronic cough patients and 15 healthy controls. Capsaicin cough provocation tests, which determine the threshold concentration of capsaicin that induces five or more consecutive coughs (C5), were also administered.Results: After comparing the results from the capsaicin cough provocation tests of the patients and the controls, the chronic cough patients were divided into two groups: an increased cough sensitivity (ICS) group (n = 28) (C5 〈 32 μmol/l) and a normal cough sensitivity (NCS) group (n = 21) (C5 ≥ 32 μmol/l). The median value of induced cough counts after a HCA challenge was 11 coughs in patients with ICS and was a significantly enhanced cough response compared to that of the patients with NCS and healthy controls (four coughs, respectively).Conclusions: A simple cough provocation test using a HCA challenge may be useful for detecting ICS. It also suggests that hyperreactive cough reflexes may be one of the mechanisms of inducing chronic cough.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1034/j.1398-9995.2003.00183.x
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