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  • 1
    Electronic Resource
    Electronic Resource
    Letter to the Editor (1999)
    Springer
    Annals of surgical oncology 6 (1999), S. 510-511 
    Details
    ISSN: 1534-4681
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s10434-999-0510-9
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  • 2
    Electronic Resource
    Electronic Resource
    Surface and bulk diffusion of HDO on ultrathin single-crystal ice multilayers on Ru(001) (1998)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 108 (1998), S. 2197-2207 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The kinetics of HDO surface and bulk diffusion on ultrathin (25–192 BL; 90–700 Å) single-crystal H216O ice multilayers were studied using a combination of laser-induced thermal desorption (LITD) probing and isothermal desorption depth-profiling. The single-crystal hexagonal ice multilayers were grown epitaxially on a single-crystal Ru(001) metal substrate with the basal (001) facet of ice parallel to the Ru(001) surface. HDO surface diffusion on the single-crystal ice multilayer was not observed within the resolution of the LITD experiment at T=140 K. These LITD surface diffusion experiments yielded an upper limit to the HDO surface diffusion coefficient of Ds≤1×10−9 cm2/s at T=140 K. The bulk diffusion coefficients were measured along the c axis of the hexagonal ice crystal which is perpendicular to the (001) plane. HDO was observed to diffuse readily into the underlying H216O ice multilayer. The measured HDO bulk diffusion coefficients ranged from D=2.2(±0.3)×10−16 cm2/s to D=3.9(±0.4)×10−14 cm2/s over the temperature range from 153 to 170 K. The HDO bulk diffusion coefficients were measured for H216O thicknesses of 25–192 BL (1 BL=1.06×1015 molecules/cm2) and initial HDO adlayer thicknesses of 2–9 BL. The HDO bulk diffusion was independent of H216O film thickness and initial HDO coverage. Arrhenius analysis of the temperature-dependent bulk diffusion coefficients yielded a diffusion activation energy of EA=17.0±1.0 kcal/mol and a diffusion preexponential of Do=4.2(±0.8)×108 cm2/s. Compared with extrapolations from macroscopic diffusion kinetics obtained earlier at temperatures close to the melting point, these bulk diffusion coefficients are larger and may reflect the perturbation of the ultrathin ice films induced by the nearby interfaces. The differences between these HDO diffusion kinetics and recently measured kinetics for H218O indicate that H/D exchange and molecular transport make comparable contributions to the HDO diffusion coefficient. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.475600
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  • 3
    Electronic Resource
    Electronic Resource
    Current transport at the p-InP|poly(pyrrole) interface (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 1001-1010 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The interface between the inorganic semiconductor p-type InP and the conjugated polymer poly(pyrrole) exhibits the electrical characteristics of a Schottky diode. Capacitance–voltage measurements yield an average barrier height of 0.62 ± 0.01 eV at temperature T =298 K. At the same temperature, the empirical quality factor, extracted from current–voltage measurements, is near unity. However, the current–voltage measurements show a deviation from thermionic emission theory as the temperature is reduced, as witnessed by the increase of the quality factor and the curvature in the Richardson plot. Such deviation is best explained by the barrier inhomogeneity model, in which the barrier becomes voltage dependent due to the interaction of a small low-barrier region with a higher surrounding potential, termed the "pinch-off" effect. Traditional current–voltage models, including image force lowering or an interfacial layer, cannot predict the temperature dependence of the current–voltage data, although thermionic field emission may facilitate current transport in the interfaces with a higher doped InP substrate. Furthermore, the probability of sufficiently energetic incident charge carriers crossing the interface, termed the transmission coefficient, is smaller than that observed in metal Schottky diodes.© 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1380220
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  • 4
    Electronic Resource
    Electronic Resource
    Current transport and the role of barrier inhomogeneities at the high barrier n-InP | poly(pyrrole) interface (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 6431-6441 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A detailed study of current transport at the Schottky-type n-InP | poly(pyrrole) interface is presented. At room temperature, this interface exhibits an average quality factor of n=1.02±0.02, a C–V barrier height of qφbCV=0.78±0.01 eV, and a surface recombination velocity over two orders-of-magnitude slower than at ideal n-InP metal interfaces. These latter two parameters imply an effective barrier height of 0.9 eV, which is among the highest values ever reported for an n-InP Schottky-type diode. The quality factor increases monotonically with decreasing temperature reaching a value of 1.23 at 98 K. Substantial curvature is also observed in a Richardson plot at reduced temperature. These temperature dependencies can be quantitatively modeled using thermionic emission theory in the presence of barrier inhomogeneities. Standard models, including thermionic emission with image force effects, interfacial layer models with and without surface states, and tunneling, do not adequately explain the temperature dependence of the quality factor and the curvature in the Richardson plot. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371707
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  • 5
    Electronic Resource
    Electronic Resource
    Calculation of transmission coefficients at nonideal semiconductor interfaces characterized by a spatial distribution of barrier heights (2001)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 115 (2001), S. 433-445 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The use of temperature-dependent current–voltage and capacitance–voltage measurements in the determination of transmission coefficients, which can be related to various other heterogeneous charge-transfer rate constants, is analyzed for semiconductor interfaces characterized by a spatial distribution of barrier heights. The level of error introduced by the unknowing neglect of heterogeneity is analyzed using a discrete parallel network of regions with potentially voltage and temperature dependent effective areas and potential barriers. In general, the unknowing neglect of heterogeneity results in an overestimation of the transmission coefficient calculated from barrier heights based on capacitance–voltage measurements and an underestimation when based on barrier heights from temperature dependent current–voltage measurements (Richardson plots). Of particular focus is the calculation of transmission coefficients at semiconductor interfaces that exhibit anomalous behavior, most notably ideality or quality factors greater than unity, due to small-scale, "pinched-off," barrier inhomogeneities characterized by voltage-dependent effective barriers. In general, the meanings of various empirical treatments of current–voltage data in light of a voltage-dependent barrier height distribution are clarified with a particular focus on the extraction of equilibrium exchange current densities and the meaning of Richardson plots. To be specific, the model of Tung for pinched-off barrier inhomogeneities is used to demonstrate that multiple orders-of-magnitude errors in the calculation of transmission coefficients are possible with systems exhibiting only mildly anomalous behavior (ideality factors less than 1.3) if heterogeneity is neglected. The conditions of applied bias, dopant density, and temperature where the error is minimized are discussed along with the criteria for the rigorous extraction of transmission coefficients. The greatest confidence in the transmission coefficients occurs when the ideality factor is unity and the capacitance–voltage barrier agrees with the Richardson plot barrier. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1375154
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  • 6
    Electronic Resource
    Electronic Resource
    Rhodium-Catalyzed Alkyne Cyclotrimerization Strategies for C-Aryl Glycoside Synthesis (1995)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 117 (1995), S. 6605-6606 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00129a030
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  • 7
    Electronic Resource
    Electronic Resource
    Spin-interference device (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 695-697 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We propose a spin-interference device which works even without any ferromagnetic electrodes and any external magnetic field. The interference can be expected in the Aharonov–Bohm (AB) ring with a uniform spin-orbit interaction, which causes the phase difference between the spin wave functions traveling in the clockwise and anticlockwise direction. The gate electrode, which covers the whole area of the AB ring, can control the spin-orbit interaction, and therefore, the interference. A large conductance modulation effect can be expected due to the spin interference. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.124485
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  • 8
    Electronic Resource
    Electronic Resource
    TREATMENT OE ACNE VULGARIS: COMBINATION OE 3% ERYTHROMYCIN AND 5% BENZOYL PEROXIDE IN A GEL COMPARED TO CLINDAMYCIN PHOSPHATE LOTION (1996)
    Oxford, UK : Blackwell Publishing Ltd
    International journal of dermatology 35 (1996), S. 0 
    Details
    ISSN: 1365-4632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-4362.1996.tb01644.x
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  • 9
    Electronic Resource
    Electronic Resource
    The Association Between Tooth Loss and Coronary Heart Disease in Men and Women (2004)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of public health dentistry 64 (2004), S. 0 
    Details
    ISSN: 1752-7325
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Objectives: This paper evaluates the relation of tooth loss to incidence of coronary heart disease in two large cohort studies. Methods: Participants included 41,407 men and 58,974 women free of any cardiovascular diseases at baseline. We recorded 1,654 incident coronary heart disease events (562 fatal events) among men during 12 years of follow-up and 544 events (158 fatal events) among women during 6 years of follow-up. Results: After controlling for important cardiovascular risk factors, compared to men with 25–32 teeth at baseline, men with 0–10 teeth had a significantly higher risk of coronary heart disease (relative risk [RR]/1.36; 95 percent confidence interval [CI]/1.11, 1.67). The relative risk increased to 1.79 (95% CI/1.34, 2.40) when limited to fatal events. Women with 0–10 teeth were also at increased risk of coronary heart disease compared to women with 25–32 teeth (RR/1.64; 95% CI/1.31, 2.05). The association was similar for fatal events (RR/1.65; 95% CI=1.11, 2.46). The association between number of teeth and incidence of coronary heart disease was similar between men with and without a history of periodontal disease, and there was no significant association between tooth loss during follow-up and coronary heart disease. Conclusions: This study showed a significant association between number of teeth at baseline and risk of coronary heart disease and the mechanisms to explain this association should be further clarified. [J Public Health Dent 2004;64(4):209–15]
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1752-7325.2004.tb02755.x
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  • 10
    Electronic Resource
    Electronic Resource
    HIGH PERFORMANCE TURNING CAPABILITIES DURING FORAGING BY BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS) (2004)
    Oxford, UK : Blackwell Publishing Ltd
    Marine mammal science 20 (2004), S. 0 
    Details
    ISSN: 1748-7692
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Large predators should have difficulty catching small prey because small animals demonstrate greater maneuverability and agility compared to large animals. The ability of a predator to capture small prey indicates locomotor strategies to compensate for inequities in maneuverability. Bottlenose dolphins (Tursiops truncatus) in Sarasota Bay, Florida feed on fish at least one order of magnitude smaller than themselves. To examine the locomotor strategies involved in prey capture, the foraging movements of these dolphins were videotaped from overhead using a remotely-controlled camera suspended from a helium-filled aerostat, which was tethered to an observation vessel. Dolphins were observed to rapidly maneuver during chases of fish in open water or around patches of rooted vegetation. Video analysis of the chase sequences indicated that the dolphins could move the rostrum through small radius turns with a mean value of 0.20 body lengths and with a minimum value of 0.08 body lengths. Mean rate of turn was 561.6°/sec with a maximum rate measured at 1,372.0°/sec. High turning rates with small turning radii were primarily the result of maneuvers in which the dolphin rolled 90° and rapidly flexed its body ventrally. The ability of dolphins to change body orientation in multiple rotational axes provides a mechanism to reduce turning radius and increase turning rate to catch small, elusive prey.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1748-7692.2004.tb01175.x
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