ENVIRONMENTAL EFFECTS INFLUENCING THE VIBRATIONAL MODES OF DNA: NANOSTRUCTURES COUPLED TO BIOMOLECULES

2008 ◽  
Vol 18 (01) ◽  
pp. 47-61 ◽  
Author(s):  
DINAKAR RAMADURAI ◽  
TAKAYUKI YAMANAKA ◽  
MILANA VASUDEV ◽  
YANG LI ◽  
VISWANATH SANKAR ◽  
...  
Keyword(s):  
Environmental Effects ◽  
Gel Electrophoresis ◽  
Charge Carriers ◽  
Vibrational Modes ◽  
Dna Nanostructures ◽  
Nanoscale Systems ◽  
Dna Strands ◽  
Rich Spectrum ◽  
Integrated Structures

The interactions of charges in DNA with the vibrational modes in DNA depend on the spectra of these vibrational modes. Using (a) the Su-Schrieffer-Heeger (SSH) Hamiltonian approach, (b) integrated structures of DNA and manmade nanostructures, and (c) gel electrophoresis techniques,1 the interaction between charges in DNA and the vibrational modes of DNA are investigated. As is well-known, DNA has a rich spectrum of modes in the THz spectral regime. The use of manmade nanostructures integrated with DNA facilitates the engineering of nanoscale systems useful in studying the role of environmental effects on the vibrational modes of DNA as well as the interaction of these modes with charge carriers in DNA. Among the DNA-based structures considered in this account are: B-DNA and Z-DNA strands related by a conformational change; and DNA molecules bound on one terminal to indirect bandgap semiconductor quantum dots. Gel electrophoresis is used as a tool for the analysis of carrier interactions in novel integrated DNA-manmade-nanostructure complexes, and models based on the SSH Hamiltonian2 are employed as a means of analyzing the interactions between the vibrational modes of DNA and charge carriers in DNA.3-4

Role of the Structure and Electronic Properties of Fe2O3-MoO3 Catalyst on the Dehydration of Isopropyl Alcohol

1993 ◽  
Vol 58 (7) ◽  
pp. 1591-1599 ◽  
Author(s):  
Abd El-Aziz A. Said
Keyword(s):  
Active Sites ◽  
Isopropyl Alcohol ◽  
Oxide Catalyst ◽  
Flow System ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalyst Composition ◽  
Surface Active

Molybdenum oxide catalyst doped or mixed with (1 - 50) mole % Fe3+ ions were prepared. The structure of the original samples and the samples calcined at 400 °C were characterized using DTA, X-ray diffraction and IR spectra. Measurements of the electrical conductivity of calcined samples with and without isopropyl alcohol revealed that the conductance increases on increasing the content of Fe3+ ions up to 50 mole %. The activation energies of charge carriers were determined in presence and absence of the alcohol. The catalytic dehydration of isopropyl alcohol was carried out at 250 °C using a flow system. The results obtained showed that the doped or mixed catalysts are active and selective towards propene formation. However, the catalyst containing 40 mole % Fe3+ ions exhibited the highest activity and selectivity. Correlations were attempted to the catalyst composition with their electronic and catalytic properties. Probable mechanism for the dehydration process is proposed in terms of surface active sites.

Political Consumerism for Sustainable Tourism

2018 ◽  
pp. 348-366
Author(s):  
Machiel Lamers ◽  
Jeroen Nawijn ◽  
Eke Eijgelaar
Keyword(s):  
Nature Conservation ◽  
Environmental Change ◽  
Social Theory ◽  
Environmental Effects ◽  
Sustainable Tourism ◽  
Global Environmental Change ◽  
Future Research ◽  
Political Consumerism ◽  
Global Environmental

Over the last decades a substantial and growing societal and academic interest has emerged for the development of sustainable tourism. Scholars have highlighted the contribution of tourism to global environmental change and to local, detrimental social and environmental effects as well as to ways in which tourism contributes to nature conservation. Nevertheless the role of tourist consumers in driving sustainable tourism has remained unconvincing and inconsistent. This chapter reviews the constraints and opportunities of political consumerism for sustainable tourism. The discussion covers stronger pockets and a key weak pocket of political consumerism for sustainable tourism and also highlights inconsistencies in sustainable tourism consumption by drawing on a range of social theory arguments and possible solutions. The chapter concludes with an agenda for future research on this topic.

The Role of Interface Vibrational Modes in Thermal Boundary Resistance

2021 ◽  
Author(s):  
Christopher M. Stanley ◽  
Benjamin K. Rader ◽  
Braxton H. D. Laster ◽  
Mahsa Servati ◽  
Stefan K. Estreicher
Keyword(s):  
Boundary Resistance ◽  
Thermal Boundary Resistance ◽  
Vibrational Modes

scholarly journals Decrease in hepatic cytochrome P-450 by cobalt. Evidence for a role of cobalt protoporphyrin

1982 ◽  
Vol 204 (1) ◽  
pp. 103-109 ◽  
Author(s):  
J F Sinclair ◽  
P R Sinclair ◽  
J F Healey ◽  
E L Smith ◽  
H L Bonkowsky
Keyword(s):  
Chick Embryo ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Cobalt Protoporphyrin ◽  
Cytochrome P 450 ◽  
Hepatic Cytochrome

Exposure of cultured chick-embryo hepatocytes to increasing concentrations of CoCl2 in the presence of allylisopropylacetamide results in formation of cobalt protoporphyrin, with a reciprocal decrease in haem and cytochrome P-450. Treatment of rats with CoCl2 (84 mumol/kg) and 5-aminolaevulinate (0.2 mmol/kg) also results in formation of cobalt protoporphyrin and a decrease in cytochrome P-450 in the liver. Hepatic microsomal fractions from rats treated with phenobarbital, CoCl2 and 5-aminolaevulinate were analysed by polyacrylamide gel electrophoresis. Cobalt protoporphyrin was associated mainly with proteins of 50000-53000 mol.wt. The results suggest that the formation of cobalt protoporphyrin occurred at the expense of the synthesis of haem, leading to a decrease in cytochrome P-450. Furthermore, the cobalt protoporphyrin that was formed may itself have been incorporated into apocytochrome P-450.

scholarly journals WHY SCREENING EFFECTS DO NOT INFLUENCE THE CASIMIR FORCE

2009 ◽  
Vol 24 (08n09) ◽  
pp. 1721-1742 ◽  
Author(s):  
V. M. MOSTEPANENKO ◽  
R. S. DECCA ◽  
E. FISCHBACH ◽  
B. GEYER ◽  
G. L. KLIMCHITSKAYA ◽  
...  
Keyword(s):  
Casimir Force ◽  
Charge Carriers ◽  
Reflection Coefficients ◽  
Dispersion Forces ◽  
Physical Reason ◽  
Lifshitz Theory ◽  
Third Law Of Thermodynamics ◽  
Applicability Condition ◽  
And Diffusion

The Lifshitz theory of dispersion forces leads to thermodynamic and experimental inconsistencies when the role of drifting charge carriers is included in the model of the dielectric response. Recently modified reflection coefficients were suggested that take into account screening effects and diffusion currents. We demonstrate that this theoretical approach leads to a violation of the third law of thermodynamics (Nernst's heat theorem) for a wide class of materials and is excluded by the data from two recent experiments. The physical reason for its failure is explained by the violation of thermal equilibrium, which is the fundamental applicability condition of the Lifshitz theory, in the presence of drift and diffusion currents.

Sign in / Sign up

Export Citation Format

Share Document