A Review of: “Natural and Synthetic Polymers by Henry L Bolker Marcel Dekker,Inc., New York, 1974”

Grafting to fibers has been studied extensively since the early 1950s as a technique for modifying their properties. Extensive reviews are available on this general subject [l-41. Although the main emphasis has been with textile fibers, considerable work has also been carried out with paper-making fibers and on paper itself [l,5].     

Announcing “New Interpretations”

Abstract

At a recent meeting of the Editorial Board held in San Francisco during the spring American Chemical Society meeting, it was decided to institute a section of the journal to be entitled “New Interpretations.”     

The Hopf Bifurcation in a Parabolic Free Boundary Problem with Double Layers

We consider a parabolic free boundary problem which has a bifurcation parameter and double interfaces. We investigate the sign change in a real part of eigenvalues and the transversality condition as a bifurcation parameter cross the critical value in order to examine the stability of the stationary solutions. The occurence of a Hopf bifurcation will be shown at a critical value.     

Time-dependent communication between multiple amino acids during protein folding

Cooperativity is considered to be a key organizing principle behind biomolecular assembly, recognition and folding. However, it has remained very challenging to quantitatively characterize how cooperative processes occur on a concerted, multiple-interaction basis. Here, we address how and when the folding process is cooperative on a molecular scale. To this end, we analyze multipoint time-correlation functions probing time-dependent communication between multiple amino acids, which were computed from long folding simulation trajectories. We find that the simultaneous multiple amino-acid contact formation, which is absent in the unfolded state, starts to develop only upon entering the folding transition path. Interestingly, the transition state, whose presence is connected to the macrostate cooperative behavior known as the two-state folding, can be identified as the state in which the amino-acid cooperativity is maximal. Thus, our work not only provides a new mechanistic view on how protein folding proceeds on a multiple-interaction basis, but also offers a conceptually novel characterization of the folding transition state and the molecular origin of the phenomenological cooperative folding behavior. Moreover, the multipoint correlation function approach adopted here is general and can be used to expand the understanding of cooperative processes in complex chemical and biomolecular systems.

Cooperativity in contact formation among multiple amino acids starts to develop upon entering the folding transition path and attains a maximum at the folding transition state, providing the molecular origin of the two-state folding behavior.     

Einflu? der Triaden-Konzentration auf die Glastemperaturen von Copolymeren

Ohne Zusammenfassung     

Photoelectron spectra of fluorine substituted diazanaphthalenes: “Even cases”

The high resolution He 584 Å photoelectron spectra of three diazanaphthalenes and some of their fluorine derivatives are presented. The qualitative model that is used frequently in the discussion of lone-pair level splittings is examined.     

Relationships among Jahn-Teller reduction factors for a Γ8 state in cubic symmetry

The general form of the reduction factors for a fourfold degenerate Γ₈ state in cubic symmetry is obtained for linear Jahn-Teller coupling to one or more vibrational modes of E(Γ₃) and/or T₂(Γ₅) symmetry.     

He(II) photoelectron spectra of esters

Intensities of X-ray photoelectron transitions from the As 3d level are theoretically analysed taking into account many-electron interactions. The latter interactions profoundly affect the relative intensities of the transitions as well as binding energies. Implications for the surface structure of GaAs are then discussed and in particular we show that As atoms having the same chemical environment are spread over distances into the surface comparable to the interatomic spacing. This supports a recently proposed layer model for the untreated surface of GaAs.