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  • 1
    ISSN: 1432-0630
    Keywords: PACS: 64.70; 65.70.+y
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract. Comparative study of solid and liquid phase ablation on the same sample by time-resolved investigations is presented in this paper. Polyethylene-glycol (PEG) 1000 having relatively low melting point (35 °C) was used in our experiments. By varying the sample temperature in the 20–80 °C range we could study the ablation mechanism in both solid and liquid (below and above the melting point) state of matter. An ArF excimer laser (λ=193 nm, FWHM=20 ns) was used for ablation at 1.95 J/cm2 fluence. Ablation processes were observed by transmission fast photographic arrangement. It was demonstrated that plasma development and expansion (primer ablation, in 0–50 ns time range), formation and propagation parameters of shock wave and contact front did not depend on sample temperature and state of matter. The secondary material ejection (between 1–100 μs) showed a strong temperature dependence. Material ejection in the case of solid target occurred in the form of dense material cloud, and in the form of splashing for liquid (molten) sample. The ejection velocity of splashed jets depended on the sample temperature, significantly. This can be due to the change of molten PEG 1000 viscosity.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 70 (2000), S. S261 
    ISSN: 1432-0649
    Keywords: PACS: 42.65.Dr; 33.20.Fb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract. We present the results of experimental and theoretical studies of fs-pulse Raman-frequency conversion in gases in the regime of medium pumping with pulses shorter than the molecular vibrational period T v. The spectral transformation of both intense excitation pulses and variably delayed injection pulses is analyzed as a function of laser parameters and gas pressure. For intense 40 fs pump pulses propagating in a SF6-filled hollow waveguide, we observed a continuous (pressure-dependent) redshift of the carrier frequency, amounting to several thousand cm−1. By transmitting a weak injection pulse with a narrow spectrum through impulsively excited SF6, we observed multiple Stokes and anti-Stokes lines of the injection radiation corresponding to scattering on the symmetric vibrational mode of SF6. Since the pumping and scattering processes are decoupled in this delayed-pulse scheme, the effect of Kerr self-action on the injection field scattering was completely eliminated. Our physical model of the fs-pulse stimulated Raman scattering is in good quantitative agreement with the observed effects.
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  • 3
    ISSN: 1432-0649
    Keywords: PACS: 42.65.Re; 42.65.Ky; 42.79.Nv
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract. We demonstrate the generation of ultraviolet 33-fs pulses with a shot-to-shot energy fluctuation of less than 3% using sum frequency mixing of visible pulses of a noncollinear optical parametric amplifier with sub-40-fs pulses of a 1-kHz Ti:sapphire-amplified system. The pulses are transform-limited (ΔνΔτ=0.36) and tunable in the range from 315 nm to 355 nm with energy above 1 μJ (2.6 μJ at 330 nm).
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  • 4
    ISSN: 1615-6110
    Keywords: Pontederiaceae ; Eichhornia ; Heterostyly ; tristyly ; long-tongued bee ; effective pollinator ; pollen transfer ; Southern Brazil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Eichhornia azurea is a tristylous species of Pontederiaceae. Moderate self-incompatibility accompanies the floral heteromorphism of this species.Eichhornia azurea is almost exclusively visited by one bee species,Ancyloscelis gigas (Anthophoridae), in South Brazil. This species has an extremely long proboscis covered with recurved hairs. Bees use these hairs to collect pollen from the anthers placed inside the narrow perianth tube ofE. azurea. Analyses of the pollen load ofA. gigas females show that they are flower constant and carry pollen from all three anther levels. The behavior ofA. gigas and its proboscis morphology make this bee species narrowly adapted and an effective pollinator for facilitating legitimate pollination ofE. azurea flowers in southern Brazil.
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  • 5
    ISSN: 1662-9779
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Copenhagen : Munksgaard International Publishers
    Allergy 55 (2000), S. 0 
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: Staphylococcus aureus has been identified as a possible trigger factor in atopic dermatitis (AD). Some 30–60% of S. aureus strains isolated from patients with AD are able to produce exotoxins with superantigenic properties, mostly staphylococcal enterotoxins A, B, C, and D (SEA–D) and toxic shock syndrome toxin-1 (TSST-1). Recently, it was demonstrated that the presence of IgE antibodies to SEA and SEB is correlated with the severity of skin lesions in children with AD. To determine the relevance of staphylococcal enterotoxins in adult patients with AD, we investigated the relationship between the severity of skin lesions and sensitization to SEA and SEB. Methods: Clinical severity was determined by the SCORAD index. Circulating IgE antibodies to SEA and SEB, serum eosinophil cationic protein (ECP) levels, and urine eosinophil protein X (EPX) levels were measured. Results: The skin condition was significantly worse in patients sensitized to SEB than in unsensitized patients. Serum ECP and urine EPX levels were found to be significantly higher in SEB-sensitized patients, confirming the higher degree of cutaneous inflammation. Conclusions: Our results demonstrate a relationship between severity of skin lesions and sensitization to SEB in adult patients with AD, but a relationship between disease activity and sensitization to SEA could not be shown.
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  • 7
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We investigate the impact of the deposition of low work function metals such as calcium on thin layers of fluorene-type polymers by time-of-flight secondary ion mass spectroscopy. An implantation process rather than a slow metal diffusion is found to be the most probable source of metal contamination within the polymer layers. This contamination extends to a range of several tens of nanometers in the organic layers. Photoluminescence and electroluminescence measurements are performed with varying calcium layer thicknesses. The luminescence efficiency exhibits a strong correlation with the depth profile of the calcium present within the polymer. The results are discussed with respect to the exciton diffusion length in the fluorene polymer. A numerical model including exciton formation, migration, and quenching is proposed in order to describe the observed phenomena. © 2000 American Institute of Physics.
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  • 8
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Structural genes of phospholipid biosynthesis in the yeast Saccharomyces cerevisiae are transcriptionally co-regulated by ICRE (inositol/choline-responsive element) promoter motifs. Gene activation by an ICRE is mediated by binding of the Ino2/Ino4 transcription factor, whereas repression in the presence of high concentrations of inositol and choline (IC) requires an intact Opi1 repressor. However, the mechanism of specific repression and the functional interplay among these regulators remained unclear from previous work. Using in vivo as well as in vitro interaction assays, we show binding of the pleiotropic repressor Sin3 to the pathway-specific regulator Opi1. The paired amphipathic helix 1 (PAH1) within Sin3 and OSID (Opi1–Sin3 interaction domain) in the N-terminus of Opi1 were mapped as contact sites. The regulatory significance of the Opi1–Sin3 interaction was shown by the obvious deregulation of an ICRE-dependent reporter gene in a sin3 mutant. Opi1 also interacts with a newly identified functional domain of the transcriptional activator Ino2 (RID, repressor interaction domain). These results define the molecular composition of the transcription complex mediating control of ICRE-dependent genes and allow a hypothesis on the flow of regulatory information in response to phospholipid precursors.
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  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of advanced nursing 47 (2004), S. 0 
    ISSN: 1365-2648
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background.  Emancipation as a nursing concept is derived from a long-standing history of social oppression and is easily addressed by both critical social theory and feminist theory. It is the apparent concept to describe a phenomenon witnessed in nursing when caring for women in the decision-making process about health care issues. Emancipation has been recognized by expert clinical observation.Aim.  The aim of this paper is to define the concept of emancipation for possible future application to nursing practice for the promotion of humanistic nursing care in women's health, specifically applied to the decision-making process.Method.  A literature search was carried out using the CINAHL database and the keywords nursing and emancipation, and covering the period 1985–2003. The Rodgers and Knafl (2000) method of concept analysis was then used to derive a conceptual meaning of emancipation that benefits patient care as well as professional nursing development. Emancipation is broken down into antecedents, attributes and consequences. Related concepts are also explored, compared and discussed to synthesize relevant characteristics.Findings.  This concept analysis identifies emancipation in decision-making as a nursing phenomenon by discussing the antecedent of oppression and exploring the identified attributes: (a) empowerment, (b) personal knowledge, (c) social norms, (d) reflection and (e) flexible environment. The consequence of emancipation is free choice. It is a futuristic concept with strong historical ties in need of exploration and development within the context of women's health care in relation to decision-making.Conclusions.  The concept model illustrates emancipated decision-making, with its five attributes in relation to oppression as a non-linear phenomenon. Areas for further study include the exploration of the contribution of each critical attribute and its relationship to emancipated decision-making, and the decision-making process in relation to patient satisfaction and how long the person continues to adhere to the decision. Also the professional nursing role in promotion of emancipated decision-making is virtually unexplored, but is an important concept in the paradigm of shared decision-making about health care alternatives.
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  • 10
    ISSN: 1572-8773
    Keywords: siderophore analog ; amino acid ; dipeptide ; triscatecholate ; synthesis ; Gram-negative bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract New analogs of bacterial siderophores with one, two or three catecholate moieties were synthesized using various mono- and diamino acid and dipetide scaffolds, respectively. In addition to 2,3-dihydroxybenzoyl siderophore analogs and their acylated derivatives, 3,4-dihydroxybenzoyl derivatives were prepared. Furthermore, the synthesis of a new triscatecholate serving as an intimate model for enterobactin is reported. Most of the new compounds gave a positive CAS-test and were active as siderophores tested by growth promotion assays with a set of siderophore indicator mutants under iron limitation. Structure-activity-correlations have also been studied.
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