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  • 1
    Electronic Resource
    Electronic Resource
    The formation, photodissociation, and bond structure of cobalt–sulfur cluster ions (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 9528-9533 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The formation and photodissociation of cobalt–sulfur cluster ions (ConS+m) produced by laser ablation on a tablet of well-mixed cobalt and sulfur powder were studied with a home-built tandem time-of-flight (TOF) mass spectrometer. In the mass spectrum, there are many intense peaks of more stable cluster ions ConS+m signified as follows: n=2–5,7, m=n−1; n=6,8–11, m=n−2; n=12–13, m=n−3; n=14–16, m=n−4. The photolysis of the mass-selected cluster ions was performed with a 248 nm excimer laser. The dissociation patterns support the above composition results. Previous theories about clusters do not explain the experimental results. A relationship between the electron number and orbital number of more stable clusters was recognized. Ab initio calculations were performed on two small cluster ions to determine stable geometries. © 1994 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.467984
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  • 2
    Electronic Resource
    Electronic Resource
    Aluminum–sulfur cluster ions: Formation and photolysis (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 1219-1224 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Aluminum–sulfur cluster ions were obtained by direct laser ablation (248 nm, ≥10 MW/cm2) and analyzed with a tandem time-of-flight mass spectrometer. The regular peaks of cluster ions having composition of AlS+(Al2S3)n (n=1,2,3,...,31) were shown on the first time-of-flight mass spectrum (TOF-MS). The cluster ions of a certain mass number (m/e) could be selected and photolyzed by an ArF laser (193 nm, 1 MW/cm2). The product ions were analyzed by a second TOF-MS. It was found that the cluster ions lost (Al2S3)x (x=1, 3, or 4) and became smaller cluster ions of the same stable formula AlS+(Al2S3)n−x. Cagelike structures were proposed to be possible for these stable cluster ions. Semiempirical and ab initio quantum chemical calculations have also been performed for some of the clusters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.467814
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  • 3
    Electronic Resource
    Electronic Resource
    The production and photodissociation of iron–sulfur cluster ions (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 1765-1770 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Iron–sulfur cluster ions FenSm+ (n=1–13, m=1–13) were produced by direct laser ablation on a solid sample containing a mixture of iron and sulfur powder. UV photodissociation of the cluster ions was studied with a tandem time-of-flight mass spectrometer. It was found that all the cluster ions with compositions of m=n, m=n−1, or m=n+5 were relatively more abundant, indicating that they were stable. The photodissociation results of the FenSm+ ions showed that, for parent ions with n(very-much-less-than)m, the main channels were sequential losses of neutral S atoms until n∼m, while for parent ions with n∼m, the main product ions had compositions of smaller m=n or m=n−1. From these experimental results, it is proposed that the FenSn+ cluster ions might have structures similar to those of the FenS*n cores in iron–sulfur proteins, while the FenSm+ (m(approximately-greater-than)n) cluster ions could be considered to have structures with the FenSn+ cores surrounded by some peripheral S atoms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.465293
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  • 4
    Electronic Resource
    Electronic Resource
    A new design for study on reactivity of clusters (1998)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 69 (1998), S. 1837-1839 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: This article reports on a new apparatus, called the laser double ablation reactor, for studies on the reactivity of clusters. Structure and operative principle of the apparatus were presented. With this apparatus reactions between manganese/carbon clusters and sulfur clusters, and between silver and sulfur clusters were studied. The experiments indicate that manganese/carbon clusters appear inert when they react with sulfur clusters, while for reactions between silver and sulfur clusters, the products [AgS4]+, [AgS8]+, [AgS12]+, and [AgS16]+, mainly are obtained. In comparison to the results obtained by Fourier transform ion cyclotron resonance, it shows that the new apparatus is very efficient for study on reactions between clusters. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1148851
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  • 5
    Electronic Resource
    Electronic Resource
    2-Iodomelatonin prevents apoptosis of cerebellar granule neurons via inhibition of A-type transient outward K+ currents (2005)
    Oxford, UK : Munksgaard International Publishers
    Journal of pineal research 38 (2005), S. 0 
    Details
    ISSN: 1600-079X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract:  Compelling evidence indicates that excessive K+ efflux and intracellular K+ depletion are key early steps in apoptosis. Previously, we reported that apoptosis of cerebellar granular neurons induced by incubation under low K+ (5 mm) conditions was associated with an increase in delayed rectifier outward K+ current (IK) amplitude and caspase-3 activity. Moreover, the melatonin receptor antagonist 4P-PDOT abrogated the effects of 2-iodomelatonin on IK augmentation, caspase-3 activity and apoptosis. Here, we show that incubation under low K+/serum-free conditions for 6 hr led to a dramatic increase in the A-type transient outward K+ current (IA) (a 27% increase; n = 31); in addition, fluorescence staining showed that under these conditions, cell viability decreased by 30% compared with the control. Treatment with 2-iodomelatonin inhibited the IA amplitude recorded from control and apoptotic cells in a concentration-dependent manner and modified the IA channel activation kinetics of cells under control conditions. Moreover, 2-iodomelatonin increased the viability of cell undergoing apoptosis. Interestingly, 4P-PDOT did not abrogate the effect of 2-iodomelatonin on IA augmentation under these conditions; in the presence of 4P-PDOT (100 μm), 2-iodomelatonin reduced the average IA by 41 ± 4%, which was similar to the effect of 2-iodomelatonin alone. These results suggest that the neuroprotective effects of 2-idomelatonin are not only because of its antioxidant or receptor-activating properties, but rather that 2-iodomelatonin may inhibit IA channels by acting as a channel blocker.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-079X.2004.00174.x
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  • 6
    Electronic Resource
    Electronic Resource
    Functional Behaviour of Human Periodontal Ligament Cells around Various Dental Implants (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 361-363 (Nov. 2007), p. 837-840 
    Details
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: In the present investigation, four titanium (Ti) surfaces of dental implants were comparedthrough in vitro systems. The surface roughness of Ti was measured by TR240 mobile surfaceroughmeter. The Ti implants were seeded with human periodontal ligament cells (hPLDCs) andmaintained for a period of 0-7 days. The adhesion, proliferation, and differentiation of hPLDCswere observed by using Cell morphology, cell counting and Osteocalcin (OC) immunofluorescentstaining. Results suggest that surface roughness of titanium favors hPDLCs behavior and improvescell adhesion, proliferation, and differentiation
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/56/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.361-363.837.pdf
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  • 7
    Electronic Resource
    Electronic Resource
    The formation and photolysis of tantalum sulfide cluster ions (1993)
    Springer
    The European physical journal 26 (1993), S. 246-248 
    Details
    ISSN: 1434-6079
    Keywords: 82.30.N ; 36.40 ; 82.50.F
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Tantalum sulfide cluster ions were produced by direct laser ablation, and were studied with a tandem time-of-flight mass spectrometer. The main dissociation channel of the UV-photolysis (248 nm) of tantalum sulfide cluster ions is sequent S2 loss. Structures with Ta3S4 and Ta4S6 as frameworks were suggested for the large tantalum sulfide cluster ions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01425679
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  • 8
    Electronic Resource
    Electronic Resource
    Relative rates of bromination and chlorination of 4-substituted cyclopentenes in methanol, ethanol and acetic acid (1989)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 2 (1989), S. 26-34 
    Details
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A set of 4-monosubstituted cyclopentenes, , were synthesized and their relative rates (kX/kH) for bromination and chlorination were determined in methanol, ethanol and acetic acid at 25 °C by competitive method. log(kX/kH) for most of the substituents can be correlated by means of Taft's equation, log(kX/kH) = ρI σI + C. In methanol ρI, Br2 = -2·91, ρI, Cl2 = -0·49, in ethanol ρI, Br2 = -3·07, ρI, Cl2 = -0·70 and in acetic acid ρI, Br2 = -1·64, ρI, Cl2 = -0·65. The presence of C(〈0) is due to a constant steric effect. The deviation of X = H is ascribed to the absence of the steric effect and that of X = CO2Me and CO2Et is accounted for in terms of anchimeric assistance. For chlorination no anchimeric assistance was observed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/poc.610020104
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  • 9
    Electronic Resource
    Electronic Resource
    Surface crystalline characteristics of polyurethane investigated by atomic force microscopy (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 61 (1996), S. 2225-2228 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A polyester - urethane was synthesized by the reaction of 2,4-toluylene diisocyanate (TDI) with poly(butylene glycol adipate) (PBGAD) using 1,4-butanediol (BDO) as a chain extender. Atomic force microscopy was employed to examine the surface morphologies of polyurethane (PU) films formed by heat treatment as well as at room temperature. At both conditions the surface of the PU film appeared as a spherulitic structure with a varied diameter and vertical height. Furthermore, the crystalline structure of heat-treated film was denser than that of the film formed at ambient. © 1996 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Correlation of change in electrical resistance with strain of carbon fiber-reinforced plastic in tension (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 60 (1996), S. 1595-1599 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A study was carried out on the variation in the electrical resistance of carbon fiber-reinforced unsaturated polyester/polyurethane (UP/PU) IPN composites during static tension, cyclical loading, and unloading in tension. The resistance was found to vary nonlinearly with strain and increase abruptly when the composite approached the fracture. Under a certain constant tension, the change in electrical resistance showed time dependece, and it is suggested that the creep of the IPN network imposed an impact on the variation of resistance. The resistance probing revealed that carbon fiber-reinforced plastic can function as a sensor that is capable of self-diagnosing the fatal fracture in composites. © 1996 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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