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BOOKS DEVOTED TO open structure have been few and far between. Their authors have been concerned with general aesthetics (Umberto Eco, L'Opera aperta [Milan: Bompiani, 1962]) or music historiography and theory (Konrad Boehmer, Zur Theorie der offenen Form in der neuen Musik [Darmstadt: Tonos, 1967]; Gary Potter, "The Role of Chance in Contemporary Music," [Ph.D. diss., Indiana University, 1971]). None has tackled the problem of criticism as related to open structure, at least not explicitly. The first, to my knowledge, to do so is Thomas DeLio in Circumscribing the Open Universe (Lanham MD: University Press of America, 1984). He does not treat the problem on a theoretical level, but each of the five essays (on Cage, Feldman, Wolff, Ashley, and Lucier respectively) which comprise the book is a practical instance of open-structure music criticism. The problem which the (would-be) critic of open-structure music has to

The construction of radar systems operating at millimetric and sub-millimetric wavelengths has necessitated the design and manufacture of a wide range of new microwave components. Manufacturing techniques have been developed for the production of components to operate in the frequency range from 30 GHz to 325 GHz using the fundamental mode in rectangular waveguide. Descriptions of some of these components and techniques are given, together with details of other higher frequency open structure and non-fundamental mode components. Planar millimetric circuitry, produced by photolithography, has been developed for use in harsh environments and the characteristics of a sub-system constructed in this manner are described. Finally, both the design and operation of two millimetric coherent radar systems are discussed and some details of their performance are given.

Systematic non-empirical SCF-MO calculations were carried out on the two limiting structures of C2H4SH+. In both of these cases two different atomic orbital basis sets were used. The results indicate that the open structure (β-thioethyl cation) lacks thermodynamic stability and spontaneously interconverts into the bridged structure (thiiranium ion). The pyramidal inversion at sulphur in the thiiranium ion was computed to be 78.11 kcal mol–1.

Alternatives for less and less effective antibiotic treatment of bacterial infections, are amongst others based on nanotechnological innovations, like carbon-dots. However, with a focus on chemistry, important characteristics of bacterial strains, like (in-)ability to produce extracellular-polymeric-substances (EPS) are often neglected. EPS is the glue that certain bacterial strains produce to keep a biofilm together. Here we report on synthesis of novel, pH-responsive, 2,3-dimethylmaleic-anhydride modified carbon-dots (C-DMMA-dots). C-DMMA-dots, like unmodified C-dots without DMMA, were little bactericidal. However, C-DMMA-dots reduced volumetric-bacterial-density within the acidic-environment of a biofilm for a non-EPS-producing Staphylococcus epidermidis strain, indicative for a more open structure. Such a structural disruption was not observed for an EPS-producing strain. Disrupted biofilms of the non-EPS-producing strain pre-exposed to C-DMMA-dots at pH 5.0, were more amenable to vancomycin penetration and killing of their inhabitants than biofilms of EPS-producing-staphylococci. Herewith, we describe a new role of carbon-dots as synthetic disruptants of biofilm structure. It is a partial success story, identifying the challenge of making carbon-dots that act as a universal disruptant for biofilms of strains with different microbiological characteristics, most notably the ability to produce or not-produce EPS. Such carbon-dots, will enable more effective clinical treatment of bacterial infections combined with current antibiotics.