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  • 1
    Electronic Resource
    Electronic Resource
    Bi12(GaxBi1−x)O19.5 optical waveguides grown by pulsed laser deposition (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 8210-8215 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Bi12(GaxBi1−x)O19.5 (BGaO) films with thickness in the range 100–1000 nm have been deposited on (100) Y-stabilized zirconia (YSZ) and (100) Bi12GeO20 (BGO) substrates using a KrF excimer pulsed laser and polycrystalline targets with composition x=0.63–0.72. The laser power density threshold for ablation of the targets has been determined to be J0=4.8 J/cm2. A deposition rate of 0.03 A(ring)/pulse was found for the substrate-target distance (6 cm) and laser fluence (J=7 J/cm2) used. Transparent and crystalline films were obtained heating the substrate in the 450–550 °C range under 1.5×10−1 mbar of oxygen pressure. Films deposited on hot substrates have a Ga stoichiometry x=0.5 but a Bi content slightly lower than that corresponding to sillenite. Films deposited on YSZ show preferential orientation. From the x-ray diffraction results and the comparison of the ionic distributions, it has been concluded that the most likely orientation between both lattices is 〈310〉{130}BGaO(parallel)〈011〉{100}YSZ. A {100}BGaO(parallel){100}BGO epitaxy has been inferred from Rutherford backscattering analysis. On both substrates the films behave as step waveguides with refractive index close to the value determined in bulk BGaO. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.362461
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  • 2
    Electronic Resource
    Electronic Resource
    Transport and photoluminescence of hydrogenated amorphous silicon–carbon alloys (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 3164-3173 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The optoelectronic properties of hydrogenated amorphous silicon–carbon alloys (a-SiC:H) are studied over the entire compositional range of carbon content. The films are prepared using radio-frequency glow discharge and optimization was made with respect to deposition power and pressure, hydrogen dilution, and methane (or ethylene) -to-silane gas phase ratio. Regardless of the deposition conditions and source gases used, the optical, structural, and transport properties of the a-SiC:H alloys followed simple universal dependencies related to changes in the density of states associated with their structural disorder. The Urbach tail energy Eu and the B factor of the Tauc plot correlate with E04 (defined as the energy at which the absorption coefficient is equal to 104 cm−1) taken from photothermal deflection spectroscopy measurements. Up to E04pds≈2.6 eV, Eu increases monotonically from 50 up to ≈200 meV, while the B factor decreases from ≈800 down to ≈200 cm−1/2 eV−1/2. Above E04pds≈2.6 eV, both Eu and B remain approximately constant. The photoconductivity decreases exponentially with E04pds and is below 10−10 Ω−1 cm−1 for E04pds≥2.6 eV. Room-temperature photoluminescence is observed when E04pds≥2.6 eV. The photoluminescence peak position lies an average of 0.6 eV below the value of E04pds and increases linearly with decreasing value of the B factor of the Tauc plot. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.360005
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  • 3
    Electronic Resource
    Electronic Resource
    Arsenic-doped Si(001) gas-source molecular-beam epitaxy: Growth kinetics and transport properties (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 1290-1292 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Arsenic-doped Si(001) layers with concentrations CAs up to 5×1018 cm−3 were grown on Si(001)2×1 at temperatures Ts=575–900 °C by gas-source molecular-beam epitaxy (GS-MBE) using Si2H6 and AsH3. This is almost an order of magnitude higher than the initially reported "maximum attainable" saturated CAs value for GS-MBE from hydride precursors. At constant JAsH3/JSi2H6, CAs decreases, while the film growth rate RSi increases, with Ts. Temperature programmed desorption measurements show that As segregates strongly to the growth surface and that the observed decrease in CAs at high film growth temperatures is primarily due to increasingly rapid arsenic desorption from the segregated layer. Decreasing Ts enhances As incorporation. However, it also results in lower film growth rates due to higher steady-state As surface coverages which, because of the lone-pair electrons associated with each As adatom, decrease the total dangling bond coverage and, hence, the Si2H6 adsorption rate. At constant Ts, CAs increases, while RSi decreases, with increasing JAsH3/JSi2H6. All incorporated As resides at substitutional electrically active sites for concentrations up to 3.8×1018 cm−3, the highest value yet reported for Si(001):As growth from hydride source gases, and temperature-dependent electron mobilities are equal to those of the best bulk Si:As. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.123527
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  • 4
    Electronic Resource
    Electronic Resource
    Evidence of human placental glucose production in viva (1998)
    Oxford, UK : Blackwell Publishing Ltd
    BJOG 105 (1998), S. 0 
    Details
    ISSN: 1471-0528
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-0528.1998.tb09981_25.x
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  • 5
    Electronic Resource
    Electronic Resource
    Immunohistochemical study of c-erbB-2 expression in carcinoma ex-pleomorphic adenoma (1996)
    Oxford, U.K. and Cambridge, USA : Blackwell Science Ltd
    Histopathology 28 (1996), S. 0 
    Details
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: A series of 19 cases of carcinoma ex-pleomorphic adenoma was studied for the immuno-expression of c-erbB-2 oncoprotein. Twelve tumours showed a malignant component with only one histological type; in the remaining seven there was co-existence of areas of various carcinoma types, adenocarcinoma NOS being the most frequent. Membranous c-erbB-2 reactivity was found in 21.1% of the cases, all corresponding to high-grade adenocarcinomatous areas. The low-grade carcinoma types that formed the malignant mixed tumours components were negative. Benign pleomorphic adenoma areas, either adjacent or intermingled with carcinomatous areas, were also consistently negative, proving that c-erbB-2 accumulation is associated with the acquisition of the malignant phenotype. The finding of a preferential association between c-erbB-2 overexpression and high-grade malignant mixed tumour may indicate prognostic implications for the oncogene protein and may also be indicative of its specific relationship with the putative pathway of malignant transformation in pleomorphic adenomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2559.1996.d01-424.x
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  • 6
    Electronic Resource
    Electronic Resource
    Aspectos Morfologicos e Histoquimicos de los Musculos Extraoculares del Zorrillo (Didelphis albiventris) (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Anatomia, histologia, embryologia 26 (1997), S. 0 
    Details
    ISSN: 1439-0264
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The extraocular muscle fibres of the South-American opossum were determined according to their metabolic profiles using NADH-diaforase, and myofibrilar ATPase after pre-incubation in both acid (pH 4.3) and alkaline (pH 10.4) media. Three muscles were selected to study the arrangement of the fibres (obliquous dorsalis, rectus dorsalis and rectus lateralis muscles). It was demonstrated that they are organized in two layers: the orbital layer composed by small diameter fibres and the global layer with three-times thicker fibres than the former. The global layer has three fibre types: white, red and intermediate; while the orbital layer presents two fibre types, which react differently to the ATPase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1439-0264.1997.tb00127.x
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  • 7
    Electronic Resource
    Electronic Resource
    Histochemical Study of the Extensor Digitorum Longus and Soleus Muscles in Alcoholic Rats (1999)
    Oxford, UK : Blackwell Science, Ltd
    Anatomia, histologia, embryologia 28 (1999), S. 0 
    Details
    ISSN: 1439-0264
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The extensor digitorum longus (EDL) and soleus (SOL) muscle fibres from albino rats submitted to experimental chronic alcoholism were evaluated in accordance with their metabolic and morphometric profiles. Twenty-seven male animals aged 4 months and weighing approximately 400 g were used. The animals were divided into three groups: control, isocaloric and alcoholic and sacrifices were carried out after 5, 10 and 15 months. The muscles were dissected, removed, cross-sectioned in a cryostat and submitted to the NADH (nicotinamide adenine dinucleotide) reaction. The SO (slow-twitch-oxidative), FG (fast-twitch-glycolytic) and FOG (fast-twitch-oxidative-glycolytic) muscle fibre types exhibited a polygonal, triangular or rounded shape and did not present noteworthy modifications in either muscles during the study. The cross-sectional areas of the fibres from the studied muscles did not present significant differences during the observations. Fibre area behaved similarly in the alcoholic animals up to the 10th month, i.e. it was decreased, as also observed in the other groups. At 15 months, however, all fibres were increased, with a predominance of FG fibres in the SOL muscle. Changes in fibre population were observed mainly in the SOL muscle of alcoholic animals: SO fibres were initially increased in number but decreased after the 10th month, and the opposite was observed for the population of FG fibres. FOG fibres increased linearly in number throughout the experiment. The statistical analysis showed nevertheless that the fibre population and cross-sectional area changes were not significant. In the alcoholic animals quantitative variations of muscle fibres were more evident in the SOL muscle, suggesting that the SOL muscle is more sensitive to the toxic action of ethanol. The results concerning the increased fibre diameter in alcoholic animals would be associated with muscle oedema induced directly or indirectly by the ethanol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1439-0264.1999.00226.x
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  • 8
    Electronic Resource
    Electronic Resource
    A block active set algorithm for large-scalequadratic programming with box constraints (1998)
    Springer
    Annals of operations research 81 (1998), S. 75-96 
    Details
    ISSN: 1572-9338
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Economics
    Notes: Abstract An algorithm for computing a stationary point of a quadratic program with box constraints(BQP) is proposed. Each iteration of this procedure comprises a guessing strategy whichforecasts the active bounds at a stationary point, the determination of a descent direction bymeans of solving a reduced strictly convex quadratic program with box constraints and anexact line search. Global convergence is established in the sense that every accumulationpoint is stationary. Moreover, it is shown that the algorithm terminates after a finite numberof iterations, if at least one iterate is sufficiently close to a stationary point which satisfiesa certain sufficient optimality condition. The algorithm can be easily implemented for sparselarge-scale BQPs. Furthermore, it simplifies for concave BQPs, as it is not required to solvestrictly convex quadratic programs in this case. Computational experience with large-scaleBQPs is included and shows the appropriateness of this type of methodology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018990014974
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  • 9
    Electronic Resource
    Electronic Resource
    Administration of tourniquet (1996)
    Springer
    Archives of orthopaedic and trauma surgery 116 (1996), S. 97-100 
    Details
    ISSN: 1434-3916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract One hindlimb of mice was subjected to 60, 90 and 120 min ischemia by application of a tourniquet followed by a 60-min reperfusion period. An additional experimental group received a tourniquet for 90 min without subsequent reperfusion. The soleus muscle (from the contralateral side also as control) was removed and evaluated for muscle weight, protein weight, protein content, and glutathione concentrations. Ischemia alone without subsequent reperfusion did not produce significant changes. With postischemic reperfusion, the protein content and muscle weight increased, probably because of an increased capillary permeability, leading to muscle edema. Oxidative stress was also present during reperfusion, correlating well with the changes in protein content. The intensity of these alterations appeared to depend on the period of ischemia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004020050077
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  • 10
    Electronic Resource
    Electronic Resource
    Administration of tourniquet (1996)
    Springer
    Archives of orthopaedic and trauma surgery 116 (1996), S. 101-105 
    Details
    ISSN: 1434-3916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An experimental group of mice were subjected to a hindlimb tourniquet for 90 min followed by 60 min postischemic reperfusion (ischemia/reperfusion, I/R). Two further groups with the same experimental procedure received allopurinol to inhibit endothelial xanthine oxidase to produce oxygen free radicals (I/R-allo) or vitamin E as a radical scavenger (I/R-vitE). The soleus muscle was examined, and the contralateral muscle served as control. Glutathione (both reduced and oxidized forms, GSH and GSSG) concentrations and the relative protein content were measured. Additionally, the muscles were examined under the electron microscope for pathological alterations. The results showed: (i) the existence of much oxidative stress in the I/R group, but not in the I/R-allo and I/R-vitE groups; (ii) an increased protein content indicative for high capillary permeability in the I/R group, but not in the I/R-allo and I/R-vitE groups; (iii) considerably fewer capillary endothelial disturbances in the I/R-allo and I/R-vitE groups than in the I/R group. We conclude that allopurinol and vitamin E diminished the occurrence of oxidative stress and of edema in postischemic skeletal muscle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004020050078
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