Interaction of C60 with carbon nanotubes and graphite

The interaction of C60 with single-wall carbon nanotubes (SWNTs) and graphite is studied experimentally by thermal desorption spectroscopy and theoretically by molecular-mechanics and molecular-dynamics calculations. The van der Waals parameters and force field for C60-graphene and C60-SWNT interactions are derived from the low-coverage C60 binding energy to the graphite surface. We use these to compare the efficiency of different mechanisms by which C60 can be encapsulated into SWNTs.     

On the Evaluation of the Evolution Operator Z Reg( R 2, R 1) in the Diakonov–Petrov Approach to the Wilson Loop

We evaluate the evolution operator Z _Reg(R ₂,R ₁) introduced by Diakonov and Petrov for the definition of the Wilson loop in terms of a path integral over gauge degrees of freedom. We use the procedure suggested by Diakonov and Petrov (Physics Letters B 224 (1989) 131) and show that the evolution operator vanishes. PACS numbers: 11.10.-z; 11.15.-q; 12.38.-t; 12.38.Aw; 12.90.+b.     

Evidence for a wide extra-astrocytic distribution of S100B in human brain

Background  

S100B is considered an astrocytic in-situ marker and protein levels in cerebrospinal fluid (CSF) or serum are often used as biomarker for astrocytic damage or dysfunction. However, studies on S100B in the human brain are rare. Thus, the distribution of S100B was studied by immunohistochemistry in adult human brains to evaluate its cell-type specificity.     

The Aza‐Morita–Baylis–Hillman Reaction: A Mechanistic and Kinetic Study

The aza‐Morita‐Baylis–Hillman (aza‐MBH) reaction has been studied in a variety of solvents, a selection of imine substrates and with various combinations of PPh₃ and para‐nitrophenol as the catalyst system. The measured kinetic data indicates that the effects of solvent and protic co‐catalyst are strongly interdependent. These results are most easily reconciled with a mechanistic model involving the reversible protonation of zwitterionic intermediates in the catalytic cycle, which is also supported by ³¹P NMR spectroscopy and quantum chemical studies.     

Two remarks on generalized hexagons

In this paper, the point-distance-2-regular hexagons are characterized as the only hexagons for which the intersection sets have size one and containing on ovoidal subspace all the points of which are 3-regular. We also give a characterization of the finite split Cayley hexagon of even order.     

The resistivity of liquid alloys

The theory of the resistivity of dilute binary alloys in the liquid state is briefly reviewed, and its application to certain systems based upon the alkali metals, especially lithium containing small amounts of magnesium, is discussed in quantitative detail. There appears to be a serious discrepancy in the case of Li-Mg, which shows up especially in the temperature variation of the resistivity. It is shown that the Born approximation, upon which the theory is based, may not be entirely valid, but this does not serve to dispose of the discrepancy.

The paper includes some remarks about the theory of the Knight shift in liquid alloys.     

Strategies of loop recombination in ciliates

The concept of breakpoint graph, known from the theory of sorting by reversal, has been successfully applied in the theory of gene assembly in ciliates. We further investigate its usage for gene assembly, and show that the graph allows for an efficient characterization of the possible orders of loop recombination operations (one of the three types of molecular operations that accomplish gene assembly) for a given gene during gene assembly. The characterization is based on spanning trees within a graph built upon the connected components in the breakpoint graph. We work in the abstract and more general setting of so-called legal strings.