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  • 1
    Electronic Resource
    Electronic Resource
    Frequency dependence of the plasma density for helicon plasmas (1997)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 4 (1997), S. 1463-1467 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Variations of plasma density are investigated as a function of frequency of rf power in a helicon plasma source. Abrupt, almost step-like changes in the plasma density are observed during the frequency scans under various conditions of the input rf power, the argon gas pressure, and the magnetic field. It is found that the transition frequencies shift to the lower value region as the input rf power and/or the argon gas pressure is increased, and to the higher value region as the magnetic field is increased. The observed density transitions are compared with semianalytical calculations based on the power balance relation and it has been shown that the results are in good agreement. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.872325
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  • 2
    Electronic Resource
    Electronic Resource
    GaInAsSb/AlGaAsSb multiple-quantum-well diode lasers grown by organometallic vapor phase epitaxy (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 70 (1997), S. 802-804 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A GaInAsSb/AlGaAsSb multiple-quantum-well diode laser structure consisting of Al0.6Ga0.4As0.05Sb0.95 cladding layers, Al0.3Ga0.7As0.02Sb0.98 confining layers, and four 15-nm-thick Ga0.87In0.13As0.12Sb0.88 quantum wells with 20-nm-thick Al0.3Ga0.7As0.02Sb0.98 barrier layers was grown by organometallic vapor phase epitaxy. These lasers, emitting at 2.1 μm, have exhibited pulsed threshold current densities as low as 1.2 kA/cm2. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.118227
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  • 3
    Electronic Resource
    Electronic Resource
    High-performance GaInAsSb thermophotovoltaic devices with an AlGaAsSb window (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 71 (1997), S. 3758-3760 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A large increase in the quantum efficiency (QE) and open-circuit voltage Voc of GaInAsSb thermophotovoltaic (TPV) devices is obtained by the use of an AlGaAsSb window layer compared with devices without a window layer. The TPV structure, grown on GaSb substrates by organometallic vapor phase epitaxy or molecular beam epitaxy, consists of a 1-μm-thick n-GaInAsSb base layer, a 3-μm-thick p-GaInAsSb emitter layer, a 100-nm-thick AlGaAsSb window layer, and a 25-nm-thick GaSb contacting layer. The band-gap energy of the lattice-matched GaInAsSb is 0.53–0.55 eV. The peak internal QE of the TPV cells with the window is 〉90%, compared with less than 60% for those without the window. At a short-circuit current density of ∼1000 mA/cm2, Voc of ∼300 meV is obtained for cells with the window layer, compared with less than 220 meV without the window layer. These increases are attributed to a substantial decrease in the surface recombination velocity with the window layer. Based on a standard calculation, the electron diffusion length in the p-GaInAsSb layer is at least 5 μm. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.120497
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  • 4
    Electronic Resource
    Electronic Resource
    Plasma-induced damage to n-type GaN (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 1795-1797 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effects of plasma etching on 1/f noise and photoluminescence (PL) characteristics of n-GaN have been investigated. A reduction of 1/f noise was observed after plasma exposure, a result of enhanced passivation of the reactive surface. This is attributed to the removal of carbon and the creation of a Ga-rich surface by the etching process. Nevertheless, the formation of nonradiative recombination centers impaired the PL intensity. Reconstruction of a stoichiometric surface was achieved by annealing. This induced the incorporation of carbon into GaN, deteriorating the PL performance further, but it could be restored by a chemical treatment of 10:1 HF:H2O. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1311605
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  • 5
    Electronic Resource
    Electronic Resource
    Anti-interleukin (IL)-4 and -IL-5 antibodies downregulate IgE and eosinophilia in mice exposed to Aspergillus antigens (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 52 (1997), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The effect of multiple divided doses compared with single-dose injections of antibodies to murine interleukin (IL)-4 and IL-5 in their respective downregulation of IgE and eosinophilia developing in a model of allergic aspergillosis is investigated. BALB/c mice were exposed to Aspergillus fumigatus antigens (Af) before and along with anticytokine antibodies. The kinetics of blood eosinophils, eosinophil peroxidase (EPO) in bone-marrow cells, scrum levels of IgE and Af-specific antibodies, Af-induced cytokine production and mRNA, and lung histology were studied. The results indicate that only multiple anti-IL-5 antibodies were effective in maintaining baseline levels of blood eosinophils. Multiple anti-IL-4 antibodies also downregulated eosinophils in the bone marrow, lung, and peripheral blood, although to a lesser extent than in anti-IL-5 antibody-injected mice. Significant correlation between the EPO activity and the eosinophil numbers in anticytokine antibody-treated mice was observed. The different anti-IL-4 antibody treatments downregulated IgE to the same extent. We conclude that multiple divided doses of anti-IL-5 antibodies arc required to sustain normal eosinophil levels in murine allergic aspergillosis. This information may be significant in the therapy of pulmonary allergic diseases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1398-9995.1997.tb02526.x
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  • 6
    Electronic Resource
    Electronic Resource
    Synthesis and electrorheological characterization of emulsion-polymerized dodecylbenzenesulfonic acid doped polyaniline-based suspensions (2000)
    Springer
    Colloid & polymer science 278 (2000), S. 894-898 
    Details
    ISSN: 1435-1536
    Keywords: Key words Electrorheological fluid ; Polyaniline ; Emulsion polymerization ; Dodecylbenzenesulfonic acid ; Suspension
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The electrorheological (ER) properties of dodecylbenzenesulfonic acid (DBSA) doped polyaniline suspensions in silicone oil were investigated. In contrast to chemically polymerized polyaniline in an acidic aqueous medium by oxidation polymerization, we adopted an emulsion polymerization technique in which aniline is polymerized in an emulsion of water and a nonpolar (or weakly polar) organic solvent. The effects of electric field strength and particle concentration on the ER properties of DBSA-doped polyaniline suspensions in silicone oil were then examined. Rheological measurements were also carried out using a rotational rheometer with a high-voltage generator in both controlled shear rate and shear stress modes, and the results showed that the ER properties were enhanced by increasing the particle concentration and electric field.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960000360
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  • 7
    Electronic Resource
    Electronic Resource
    Overexpression of HSP70 prevents ultraviolet B-induced apoptosis of a human melanoma cell line (2000)
    Springer
    Archives of dermatological research 292 (2000), S. 482-487 
    Details
    ISSN: 1432-069X
    Keywords: Keywords HSP70 ; Human melanoma cells ; Ultraviolet B ; Apoptosis ; Caspase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The heat shock response is a highly conserved reaction common to all cells and organisms. It has been reported that hyperthermic treatment can induce the expression of the heat shock protein (HSP) and can protect cells from ultraviolet (UV) B radiation. In this study, we evaluated the effects of induced HSP70 on resistance to UV radiation. G361 amelanotic human melanoma cells were irradiated with increasing doses of UVB. UVB irradiation caused apoptotic cell death in these cells. Following transfection with MFG.hsp70.puro plasmid, the expression of HSP70 was determined. Compared to control vector-transfected cells, hsp70-transfected cells showed significantly elevated levels of HSP70 and were highly resistant to UVB irradiation. In order to investigate the effects of HSP70 on the apoptotic pathway, the changes in caspase-3 and PARP were analyzed. Following UVB irradiation, activation of caspase-3 and cleavage of PARP were observed in control vector-transfected cells, and the changes in these molecules were inhibited in the hsp70-transfected cells. These results suggest that UVB-induced apoptosis of melanoma cells is accompanied by caspase-3 activation and PARP cleavage, which can be prevented by an overexpression of HSP70.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004030000173
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  • 8
    Electronic Resource
    Electronic Resource
    Hyaluronan and chondroitin sulfate proteoglycans are colocalized to the ciliary zonule of the rat eye: a histochemical and immunocytochemical study (1997)
    Springer
    Histochemistry and cell biology 107 (1997), S. 289-301 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  In previous studies, chondroitin sulfate proteoglycans have been localized to the periphery of the zonular fibers and the individual zonular fibrils (or microfibrils) after Cuprolinic blue staining in conjunction with chondroitinase digestions and immunogold labelling with 2-B-6 antibody. In the present study, we wished to determine if these proteoglycans are linked to hyaluronan to form a large multimolecular aggregate. To accomplish this, we localized the hyaluronan using a biotinylated hyaluronan-binding protein fragment of chondroitin sulfate proteoglycan, containing also the link protein, purified from bovine nasal cartilage. The results showed that the ciliary zonule of the rat eye was reactive with the biotinylated hyaluronan-binding probe as demonstrated by streptavidin-peroxidase-diaminobenzidine staining and streptavidin-gold labelling. Hyaluronan-gold labelling showed that the gold particles were mostly localized on the periphery of the zonular fibers, which was similar to the localization pattern of the zonule associated-proteoglycans. This hyaluronan-binding probe also strongly labelled the sites of zonule insertion over the basement membrane of the inner ciliary epithelium at the pars plana and the lens capsule at the equatorial region, which suggests its probable role in the attachment of ciliary zonule to the basement membranes. To demonstrate whether these two molecules are linked to one another, ultrastructural colocalization of both hyaluronan and chondroitin sulfate proteoglycans was performed on the same sections by double-gold labelling, and combined Cuprolinic blue staining and hyaluronan-gold labelling. Gold particles of 15 and 10 nm in sizes labelling both hyaluronan and chondroitin 4-sulfate, were colocalized to the surface of the zonular fibers. The combined Cuprolinic blue staining and hyaluronan-gold labelling showed that the gold particles were localized towards the ends of the Cuprolinic blue-stained rodlets, which strongly suggests that these chondroitin sulfate proteoglycans are linked to the hyaluronan chain to form a large aggregate surrounding the periphery of the zonular fibers. These ciliary zonule-associated proteoglycan-hyaluronan aggregates may play a role in organizing the individual zonular fibrils (microfibrils) into bundles of zonular fibers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004180050114
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  • 9
    Electronic Resource
    Electronic Resource
    Clinical characteristics of Peutz-Jeghers syndrome in Korean polyposis patients (2000)
    Springer
    International journal of colorectal disease 15 (2000), S. 35-38 
    Details
    ISSN: 1432-1262
    Keywords: Keywords Peutz-Jeghers syndrome ; Hamartomatous polyps ; Intussusception ; Cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Peutz-Jeghers syndrome is an autosomal dominant inherited disorder characterized by hamartomatous polyps in the small bowel and mucocutaneous pigmentation. Patients with Peutz-Jeghers syndrome often present as surgical emergencies with complications of the polyps, such as intussusception, bowel obstruction, and bleeding. Recently an increased risk of malignancies has also been reported. This study was initiated to determine the clinical features of Peutz-Jeghers syndrome in Korean patients, with special attention to the development of malignancies. Thirty patients with Peutz-Jeghers syndrome were investigated; their median age was 23.5 years, and symptoms appeared at a median age of 12.5 years. Family history was positive in one-half of cases, and mucocutaneous pigmentation was observed in almost all patients (93%). The jejunoileum was the most frequent site of the polyps, and there were generally 10–100 polyps. Multiple laparotomies were performed in a substantial portion of the patients, due mainly to polyp-induced bowel obstruction, and the surgical interventions were begun at a relatively young age (average 21.4 years). Four cases of small-bowel cancer and one case of breast cancer were detected in probands, at a relatively young age (mean 36 years). Cancers of the small bowel, stomach, colon, breast and cervix were diagnosed in the first relatives of the probands. Close follow-up from an early age should thus be performed in patients with Peutz-Jeghers syndrome as they are at high risk of surgical emergency and development of malignancy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003840050005
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  • 10
    Electronic Resource
    Electronic Resource
    Electrorheological characteristics of polyaniline and its copolymer suspensions with ionic and nonionic substituents (2000)
    Springer
    Colloid & polymer science 278 (2000), S. 61-64 
    Details
    ISSN: 1435-1536
    Keywords: Key words Electrorheological fluid ; N-substituted copolyaniline ; Polyaniline ; Poly(aniline-co-o-ethoxyaniline)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Electrorheological (ER) characteristics of ER fluids, composed of suspensions of semiconducting polyaniline and two different copolyaniline particles in silicone oil, were determined experimentally. Ionic sodium diphenylamine sulfonate and nonionic o-ethoxyaniline were used to synthesize copolyanilines, i.e. N-substituted copolyaniline and poly(aniline-co-o-ethoxyaniline), respectively. ER fluids composed of these three different polymers were compared with respect to their rheological properties under an applied electric field. It was found that ER fluids containing a copolymer with an ionic group exhibited the highest ER performance among polyaniline and its copolymer systems in a shear-rate region above 1 s−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960050009
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