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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    International journal of cosmetic science 26 (2004), S. 0 
    ISSN: 1468-2494
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: It has been known that high amounts of ‘heat shock proteins (HSPs)’ are produced under heat and other environmental stresses in cells. Recently, it was reported that HSP could also be accumulated in some dermal cells to protect the cellular proteins from damage caused by ultraviolet radiation. Here, the authors have focused on thermophilic cyanobacteria and the heat shock treatment. Thermophilic cyanobacteria are known to thrive under extreme environmental conditions, and produce distinctively high amounts of HSP when exposed to higher temperatures. We tested cell extract from heat-shocked cyanobacterial cells on a number of skin-related biological activities and found it significantly effective. The cyanobacterial cells, originally collected from a spa as hot as 55 °C, were cultivated in the laboratory at 50 °C and broken by a freeze-fracture method. The extract thus obtained had a superoxide dismutase (SOD)-like activity and inhibited lipid peroxide formation. We found that the extract obtained from the heat-shocked (at 63 °C) cells showed a much stronger SOD-like activity, while the inhibitory effect on lipid peroxide formation remained almost the same. Furthermore, the SOD-like activity could withstand heat up to 70 °C for as long as 1 h. Most remarkably, supplementing this heat-shocked extract strongly promoted the proliferation of human dermal fibroblast culture. Extracts from the cells grown at a regular temperature (50 °C) did not promote the proliferation of the fibroblasts. The heat-shocked extract was fractionated by ultrafiltration for further analysis. A fraction (molecular weight: 10 000–30 000) has shown the strongest activity so far. These results indicate that the heat-shocked cyanobacterial extract with its increased amounts of HSPs is a promising potent ingredient for anti-aging cosmetic materials.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 3070-3072 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A cubic Si3N4 phase/nanostructure has been characterized by means of high-resolution analytical electron microscopy. The specimen prepared from β-Si3N4 powders at a high pressure and temperature by shock wave compression contained nanometer-sized Si3N4 crystallites. The results of nano-beam electron diffraction analysis and high-resolution lattice images as well as computer simulations revealed that the Si3N4 crystallites had a cubic symmetry with spinel structure. The electron energy loss spectrum suggested that the chemical compositions of these nanostructures were close to Si3N4. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 71 (2000), S. 1548-1551 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Interferometer measurements are extremely informative in shock wave studies allowing direct evaluations of the gas density. The primary goal of the work presented is to build a laser interferometer that meets the requirements of the highest possible simplicity, economy, convenience, and ease of construction. In our experiments, we used a low average power (10 mW) He–Ne laser without complication, expense, and environmental section. The He–Ne laser interferometer with the Michelson arrangement was used to measure the line-averaged gas densities of shock waves. Temporal and spatial measurements of the density were performed for shock wave developments from high-current pulse discharges. The shock wave propagates in the radial direction of the discharge channel with supersonic speed. The shock velocity, however, decreased from 2–0.5 km/s with the distance of the shock propagation. The width of the high density region, that is in the vicinity of the shock front was compressed from 3.5 to 1.8 mm according to the time variation of the discharge current. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 6579-6581 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Magnetic properties of the intergranular phase in the bcc-Fe/NdFeB nanocomposite alloys containing Nb and Co were investigated with Mössbauer spectroscopy. The alloys were prepared with melt-spinning and post-annealing method. It is revealed that the intergranular phase is not amorphous as considered so far and consists of several thin layers outside the nanoscale grains of bcc-Fe and Nd2Fe14B. The hyperfine field in the layer on the surface of the grain is rather strong and the structure of this layer is similar to the grain. The field in the outer layers is reduced because the structure becomes indistinct gradually as the layer is apart from the grain. The high remanence and coercive field of the nanocomposite alloys may originate from the magnetic coupling between grains via the intergranular ferromagnetic phase. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 4403-4406 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The phase transformation behavior of hexagonal germanium nitride, including both α- and β-Ge3N4, has been studied under shock wave compression. The shock compressed quenched samples indicate phase transformation from hexagonal into a cubic spinel structure (γ-Ge3N4). This transformation is completed with increasing shock pressure up to 40–46 GPa (temperature of 1300–1500 K). The lattice constant of γ-Ge3N4 is measured to be 0.820 63±0.000 19 nm, and the crystal density 6.581 g/cm3, by the powder x-ray diffraction. The stability of γ-Ge3N4 also has been investigated under shock wave compression. It is found that the spinel structure is very stable, and up to at least 63 GPa (temperature of ∼1700 K) there is no indication of the formation of a postspinel phase. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 72 (2001), S. 2032-2035 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Coupled with the push-pull type velocity interferometer system for any reflector, an electronic streak camera recording system has been established, which provides subnanosecond time resolution in the detection of interferential fringes. Complete acceleration histories of Al, Au, and Pt foil plates, driven by pulsed laser beam at 30–400 GW/cm2, have been measured by using this system. For the 10-μm-thick Al foil irradiated at 280 GW/cm2, an ablative acceleration up to terminal velocity about 9 km/s within 25 ns has been determined with a velocity uncertainty of ∼1%. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 76 (2000), S. 3706-3708 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: β-Si3N4 powders were shock compressed and quenched from 12 to 115 GPa. β-Si3N4 transforms to the spinel-type Si3N4 (c-Si3N4) by a fast reconstructive process at pressures above about 20 GPa. The yield of c-Si3N4 recovered from 50 GPa and about 2400 K reaches about 80% and the grain sizes are about 10–50 nm. It is proposed that the fast transformation to c-Si3N4 occurs by rearrangement of nitrogen stacking layers, which initiates partial breakup of the SiN4 tetrahedra and formation of SiN6 octahedra at high density. Because of the advantages of massive production and the nanometer characteristics of shock-synthesized c-Si3N4, it is possible to investigate the mechanical properties experimentally and to develop new industrial applications. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 81 (2002), S. 610-612 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: For a long time, hexagonal diamond has been formed only by static and shock wave compression of well-crystallized graphites. Here, we demonstrate that cubic diamond loses its structure stability and transforms to hexagonal diamond in massive. This transformation has been completed in nanoseconds under a shock wave compression of cubic diamond, in which the shock pressure and temperature are only tens of giga pascal and hundreds of kelvin, thermodynamically being within the stability of cubic diamond. The formation of hexagonal diamond is interpreted as a direct transition (solid to solid) of cubic diamond by a kinetic mechanism due to the shear stress and enhanced temperature induced by the rapid shock wave compression. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background Seborrhoeic keratosis (SK) is a benign epidermal tumour with increased pigmentation. We have recently demonstrated that increased secretion of endothelin (ET)-1, a strong keratinocyte-derived mitogen and melanogen for human melanocytes, is intrinsically involved in the hyperpigmentation mechanism of SK. Objectives To examine whether the increased ET secretion results from cytokines that induce ET production and/or from differences in the processing of ET that lead to its final active, secreted form. Methods We used immunohistochemistry and reverse transcription–polymerase chain reaction (RT–PCR) to determine whether ET-inducing enzymes and/or cytokines are also highly expressed in SK. Results RT–PCR of mRNAs encoding interleukin (IL)-1α, tumour necrosis factor (TNF)-α and endothelin-converting enzyme (ECE)-1α demonstrated that there is an increased expression of TNF-α and ECE-1α mRNAs in SK, whereas the IL-1α transcript is rather downregulated in SK compared with that in perilesional normal epidermis. In parallel, immunohistochemical analysis of SK revealed marked immunostaining for TNF-α in basaloid cells at lower levels of the epidermis and in basal cells, and for ECE-1α in most basaloid and basal cells in comparison with their weak staining throughout the epidermis in perilesional normal controls. In contrast, immunostaining for IL-1α was almost negative in SK relative to distinctive staining throughout the epidermis in the perilesional normal controls. Conclusions These findings suggest that the increased secretion of ET-1 leading to enhanced pigmentation in SK results from the co-ordinated increased expression of TNF-α and ECE-1α.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 58 (2001), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Aqueous extracts from the skin mucus of two species of rabbitfishes Siganus fuscescens and S. guttatus showed antibacterial activity against gram-negative bacteria. Stability tests and chromatographic analyses suggested that the S. fuscescens antibacterial factor is an acidic glycoprotein with a molecular mass of 400 kDa.
    Type of Medium: Electronic Resource
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