16 research outputs found
Cyanoresin, cyanoresin/cellulose triacetate blends for thin film, dielectric capacitors
Non brittle dielectric films are formed by blending a cyanoresin such as cyanoethyl, hydroxyethyl cellulose (CRE) with a compatible, more crystalline resin such as cellulose triacetate. The electrical breakdown strength of the blend is increased by orienting the films by uniaxial or biaxial stretching. Blends of high molecular weight CRE with high molecular weight cyanoethyl cellulose (CRC) provide films with high dielectric constants
Target wise and pound foolish: A simple technique to evaluate the trade-off between economic burden and clinical benefit of monoclonal antibodies.
Impact of donor-acceptor functionalization on the properties of linearly π-conjugated oligomers: establishing quantitative relationships for the substituent and substituent cooperative effect based on quantum chemical calculations
To understand better the impact of donor-acceptor substitution on the properties of linearly π-conjugated compounds, we performed a computational study on a series of variably substituted trans-polyacetylenes, polyynes, and polythiophenes. The focus of this work is on how rapidly the impact of a given substituent or a given combination of substituents vanishes along the π-conjugated chain. The response of the structural (bond-length alternation, rotational barrier) and molecular properties ((hyper)polarizability, chemical shift) to substitution is analyzed using different protocols, including a superposition model for the evaluation of the cooperative effect of substituents in homo- and heterosubstituted oligomers. With the exception of the (hyper)polarizability, the impact of donor-acceptor substitution is found to vanish following an exponential. The rate of decay of the substituent impact is found to be characteristic for each backbone, whereas the choice of substituent determines the absolute value of the respective property. The combination of substituents is shown to determine whether the substituent cooperative effect on a property is of an enhancing or damping nature. The rate of decay of the cooperative effect on most properties, including the (hyper)polarizability, is also found to follow an exponential law
Structure, Dynamics, and Function of the Hammerhead Ribozyme in Bulk Water and at a Clay Mineral Surface from Replica Exchange Molecular Dynamics
Compared
with proteins, the relationship between structure, dynamics,
and function of RNA enzymes (known as ribozymes) is far less well
understood, despite the fact that ribozymes are found in many organisms
and are often conceived as “molecular fossils” of the
first self-replicating molecules to have arisen on Earth. To investigate
how ribozymal function is governed by structure and dynamics, we study
the full hammerhead ribozyme in bulk water and in an aqueous clay
mineral environment by computer simulation using replica-exchange
molecular dynamics. Through extensive sampling of the major conformational
states of the hammerhead ribozyme, we are able to show that the hammerhead
manifests a free-energy landscape reminiscent of that which is well
known in proteins, exhibiting a “funnel” topology that
guides the ribozyme into its globally most stable conformation. The
active-site geometry is found to be closely correlated to the tertiary
structure of the ribozyme, thereby reconciling conflicts between previously
proposed mechanisms for the self-scission of the hammerhead. The conformational
analysis also accounts for the differences reported experimentally
in the catalytic activity of the hammerhead ribozyme, which is reduced
when interacting with clay minerals as compared with bulk water
Exploiting Interfacial Water Properties for Desalination and Purification Applications
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