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  • 11
    Electronic Resource
    Electronic Resource
    Effect of Yb3+ doping on upconversion emission intensity and mechanism in Er3+/Yb3+-codoped fluorozirconate glasses under 800 nm excitation (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 6143-6149 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Er3+ singly- and Er3+/Yb3+-codoped fluorozirconate glasses were prepared. The upconversion emission intensities of the Er3+ ion around both 550 and 660 nm were measured under 800 nm excitation. The absorption band of the Yb3+ ion is located around 980 nm. Though the absorption band of Yb3+ does not interact directly with the incident light at 800 nm, both upconversion intensities around 550 and 660 nm emission increased with the increasing YbF3 concentration. We calculated the upconversion intensities around 550 and 660 nm by using rate equations and evaluated the principal upconversion mechanism in Er3+ singly- and Er3+/Yb3+-codoped samples quantitatively. We also investigated the reason for the increase of the upconversion emission intensities with the codoping of Yb3+ under 800 nm excitation. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371666
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  • 12
    Electronic Resource
    Electronic Resource
    Upconversion mechanism in Er3+-doped fluorozirconate glasses under 800 nm excitation (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 29-37 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The upconversion emission intensities of Er3+ ion around 550 and 660 nm in fluorozirconate glasses were measured under 800 nm excitation. Though energy transfer processes played an important role in upconversion mechanism at high concentration of ErF3, those have not been treated quantitatively. The energy transfer rates were calculated from the optical parameters assuming some distribution of Er3+ ions. We calculated the upconversion intensities around 550 and 660 nm by using rate equations. It was found that the dependence of upconversion emission intensities on the ErF3 concentration could be reproducible and the principal upconversion mechanism could be evaluated. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.369445
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  • 13
    Electronic Resource
    Electronic Resource
    Breakdown and destruction of heterogeneous solid dielectrics by high voltage pulses (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 6262-6267 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A mechanism explaining the breakdown of dielectrics with high intrinsic inhomogeneity like natural rocks and concrete is proposed and proved experimentally. This work has a very promising industrial application in the drilling and demolition of natural and artificial solid materials by electric pulses. The mechanism includes the breakdown of gas cavities inside the dielectric and on its surface. At a very high applied voltage, the high electric field causes the breakdown in the cavities. The displacement and conduction currents flowing through a number of such cavities result in the heating of the plasma and high pressure pulse generation. The pulsed pressure results in crack formation and finally, in the destruction of a solid material. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.368946
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  • 14
    Electronic Resource
    Electronic Resource
    Dichlorobis[4,4,5,5-tetramethyl-2-(2-pyridyl)-4,5-dihydro-1H-imidazol-1-yloxy 3-oxide]copper(II) Bis(dichloromethane) Solvate (1997)
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 53 (1997), S. 0-0 
    Details
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108270197099538
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  • 15
    Electronic Resource
    Electronic Resource
    Metal Oxide Thin Films Containing Au Nano-Particles Prepared with Gas Diffusion Method (1998)
    Springer
    Journal of sol gel science and technology 11 (1998), S. 117-124 
    Details
    ISSN: 1573-4846
    Keywords: gold metal particles ; coating films ; gas diffusion method ; surface plasma resonance ; hydroxypropyl cellulose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Au particles dispersed thin metal oxide films were prepared from precursor films containing HAuCl4 with H2S gas diffusion method. HAuCl4 was uniformly dissolved in the films as promoted by hydroxypropyl cellulose (HPC). The mechanism of the Au particle formation was studied. It was found that HAuCl4 was converted directly to Au metal particles upon contacting with H2S gas. Au particles generated by this method were characterized with small particle size, sharp size distribution and high volume fraction in the films. The surface plasma resonance absorption of Au particles shifted to longer wavelength when TiO2 component was introduced in the matrix.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008653303440
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  • 16
    Electronic Resource
    Electronic Resource
    Senescence marker protein-30 (SMP30) enhances the calcium efflux from renal tubular epithelial cells (1999)
    Springer
    Clinical and experimental nephrology 3 (1999), S. 261-267 
    Details
    ISSN: 1437-7799
    Keywords: Key words SMP30 ; Calcium efflux ; Tubular epithelia ; Calcium pump ; Calmodulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background. Senescence marker protein-30 (SMP30), a calcium binding protein, is preferentially expressed in the renal proximal tubules and hepatocytes and is presumed to play a role in Ca2+ homeostasis. Methods. To explore its physiological functions in the tubular cells, we investigated the effect of SMP30 on Ca2+ efflux via the ATP-dependent plasma membrane calcium pump. LLC-PK1 cells were stably transfected with a cDNA encoding SMP30, and the established transfectants were subjected to ATP responses. Results. Overexpression of SMP30 significantly increased Ca2+ efflux under both basal and ATP-stimulated conditions. Inhibition of calmodulin by trifluoperazine abrogated the enhanced Ca2+ efflux, suggesting that SMP30 activated the calmodulin-dependent Ca2+ pump. It is known that Ca2+ superfluous influx induces cellular injury. Compared with mock-transfected cells, LLC-PK1 cells expressing SMP30 showed resistance to cellular death triggered by Ca2+ superfluous influx. Conclusion. These results suggest the possibility that, in renal tubular cells, endogenous SMP30 participates in Ca2+ efflux via activating the calmodulin-dependent Ca2+ pump and thereby confers resistance of the cells against injury caused by high intracellular Ca2+ concentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101570050045
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  • 17
    Electronic Resource
    Electronic Resource
    Immunohistochemically demonstrated variation in expression of cathepsin E between uracil-induced papillomatosis and N-butyl-N-(4-hydroxybutyl)nitrosamine-induced preneoplastic and neoplastic changes in rat urinary bladder (1996)
    Springer
    Virchows Archiv 427 (1996), S. 589-594 
    Details
    ISSN: 1432-2307
    Keywords: Cathepsin E ; Uracil ; N-Butyl-N-(4-hydroxybutyl)nitrosamine ; Rat urinary bladder carcinogenesis ; Papillomatosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Expression of rat urinary bladder cathepsin E in benign papillomatosis induced by uracil and various stages of N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced carcinogenesis was investigated immunohistochemically. Seven-week-old, male F344/DuCrj rats were used. In the normal urothelium of control rats, cathepsin E stained in all layers of cells, although in umbrella cells and some basal cells the reaction was relatively weak. In rats given a diet containing 3% uracil for 5 weeks immunoreactivity of cathepsin E in uracil-induced papillomatosis was consistently homogeneous in all layers, but weaker than in normal urothelium. In rats given 0.05% BBN in drinking water for 12 weeks and subsequently maintained without treatment for 48 weeks cells with little cathepsin E, never observed in normal urothelium, appeared at 5 weeks above the basement membrane in the earliest stage of BBN-induced urinary bladder cancer (simple hyperplasia). Throughout the neoplastic process, groups of cells with a little cathepsin E were randomly distributed, with expression in the urothelium being markedly unstable. Almost all areas of squamous cell proliferation in TCC were negative for cathepsin E. Instability of cathepsin E expression in rat urothelium therefore appears characteristic for carcinogenesis and offers the possibility of using this feature as an early biomarker for urinary bladder carcinogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00202890
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  • 18
    Electronic Resource
    Electronic Resource
    Increase in the Potential of Osteoblasts to Support Bone Resorption by Osteoclasts In Vitro in Response to Roughness of Bone Surface (1999)
    Springer
    Calcified tissue international 65 (1999), S. 454-458 
    Details
    ISSN: 1432-0827
    Keywords: Key words: Osteoclasts — Rough surface — Bone resorption — Spleen cells — Alkaline phosphatase.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract. The development of the potential of osteoblasts to support bone resorption by osteoclasts in response to roughness on bone slices was examined in the co-incubation cell system of immature osteoclasts and osteoblastic cells. The immature osteoclasts, which need alkaline phospatase (ALP)-positive osteoblastic cells for bone resorption, were generated in mouse spleen cultures with 1, 25-dihydroxyvitamin D3 and prostaglandin E2. ALP-negative osteoblastic cells from mouse calvaria were incubated on rough surfaced bone slices for 3 days. The number of ALP-positive cells increased greatly on the rough surface, but little on the smooth surface. When immature osteoclasts were added and incubated for 1 more day, the resorption pit number and the total pit areas on the smooth surface were not much different from those before incubation but were approximately four times higher on the rough surface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002239900732
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  • 19
    Electronic Resource
    Electronic Resource
    Preparation and separation of metallobacteriochlorophylla by reversed-phase high-performance liquid chromatography (1996)
    Springer
    Chromatographia 43 (1996), S. 361-364 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Bacteriochlorophylla ; Copper(II) bacteriochlorophylla ; Zinc(II) bacteriochlorophylla
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Semi-preparative high-performance liquid chromatography has been used for the preparation of copper(II) bacteriochlorophylla [Cu(II)-BChl-a] and zinc(II) bacteriochlorophylla [Zn(II)-BChl-a]. Both compounds are separated on a reversed-phase Inertsil ODS-2 column using a mobile phase of acetone-methanol (25∶75, v/v). The fractionated metallobacteriochlorophylls (M-Bchl-a) are identified by fast atom bombardment mass spectrometry. The spectroscopic parameters such as the wavelength of absorption maxima and the molar extinction coefficients are determined using pure M-Bchl-a obtained by preparative HPLC. The HPLC method proposed here has been demonstrated to be useful for the purification and determination of components of M-Bchl-a.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02271011
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  • 20
    Electronic Resource
    Electronic Resource
    Isolation and characterization of the krev-1 gene, a novel member of ras superfamily in Neurospora crassa: involvement in sexual cycle progression (1997)
    Springer
    Molecular genetics and genomics 255 (1997), S. 429-437 
    Details
    ISSN: 1617-4623
    Keywords: Key wordsNeurospora crassa ; ras superfamily ; krev-1 ; Krev-1/rap1A/smg21A
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Genes belonging to the ras superfamily encode low-molecular-weight GTP/GDP-binding proteins that are highly conserved in wide variety of organisms. We used the polymerase chain reaction (PCR) to isolate a novel member of the ras superfamily from the filamentous fungus Neurospora crassa and obtained a mammalian Krev-1 homolog. We named the gene krev-1 and analyzed its structure and function. The krev-1 gene encodes a polypeptide of 225 amino acids, which is nearly 60% homologous to the mammalian Krev-1 p21. The krev-1 gene product (KREV1) is functionally analogous to mammalian Krev-1 p21 and Rsr1p/Bud1p, a Krev-1 homolog from the yeast Saccharomyces cerevisiae. GAL1-driven expression of KREV1 in a wild-type yeast strain resulted in a random budding pattern, as did its mammalian counterpart Krev-1 p21. We disrupted the krev-1 gene by RIP (repeat-induced point mutation), but the krev-1 disruptants showed no abnormalities. By in vitro mutagenesis, we constructed several mutant krev-1 genes (G21V, A68T, and D128A) which mimic constitutively active mutants of Ha-ras, and the krev-1 (K25N) mutant which is analogous to a dominant-negative mutant of Ha-ras. Each mutant gene was introduced into the wild-type strain and the phenotypes were analyzed. We could not observe any difference in vegetative growth between these transformants. When each strain was used as the female in mating tests, the development of perithecia from protoperithecia was inhibited in all cases. The results indicate that the krev-1 gene may be involved in sexual cycle progression.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004380050515
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