Monitoring Methylmalonic Aciduria by NMR Urinomics

The paper reports on monitoring methylmalonic aciduria (MMA)-specific and non-specific metabolites via NMR urinomics. Five patients have been monitored over periods of time; things involved were diet, medication and occasional episodes of failing to comply with prescribed diets. An extended dataset of targeted metabolites is presented, and correlations with the type of MMA are underlined. A survey of previous NMR studies on MMA is also presented.     

Aspects of the planetary Birkhoff normal form

The discovery of the Birkhoff normal form around circular, co-planar motions for the planetary system opened new insights and hopes for the comprehension of the dynamics of this problem. Remarkably, it allowed to give a direct proof (after the proof in [18]) of the celebrated Arnold’s Theorem [5] on the stability of planetary motions. In this paper, after reviewing the story of the proof of this theorem, we focus on technical aspects of this normal form. We develop an asymptotic formula for it that may turn to be useful in applications. Then we provide two simple applications to the three-body problem: we prove that the “density” of the Kolmogorov set of the spatial three-body problem does not depend on eccentricities and the mutual inclination but depends only on the planets’ masses and the separation among semi-axes (going in the direction of an assertion by V. I.Arnold [5]) and, using Nehoro?ev Theory [33], we prove, in the planar case, stability of all planetary actions over exponentiallylong times, provided mean-motion resonances are excluded. We also briefly discuss difficulties for full generalization of the results in the paper.     

Biodeterioration of Paper: A SEM Study of Fungal Spoilage Reproduced Under Controlled Conditions

Biodeterioration phenomena represent a complex of physical and chemical alteration processes in various materials, such as those constituting the objects that represent our cultural heritage. The biodegradation of paper is conditioned by several variables such as the materials from which cellulose is obtained, the manufacturing processes employed, the occurrence of other affecting substances such as lignin or metallic compounds, and by the environmental conditions in which papers are conserved. In this study, biodeterioration of paper was artificially induced in order to evaluate the role of a range of chemical and physical variables on damage caused by cellulolytic fungi. A variable pressure SEM instrument was used to characterise paper samples with different fibre origins, and alterations obtained in vitro. Two fungal strains, Aspergillus terreus Thom and Chaetomium globosum Kunze, which are cellulolytic species frequently associated with paper spoilage, were used to produce stains with characteristics close to those observable on art objects made from paper. The stains obtained on the different samples of paper were compared at both low and high magnification, in order to visualize the macro- and microscopic characteristics of paper fibres, inorganic constituents, impurities, and the deteriorating agents related to the spoiled areas. During this survey it was observed that single paper characteristics can strongly influence the intensity and the results of the fungal action. For example, the activity of a fungal strain on paper grades containing fibres of the same origin, but with different sizing, led to the formation of profoundly different stains and alterations. Moreover fungal structures, analysed by low vacuum SEM, in areas on paper corresponding to the stains appeared in different physiological states suggesting an important effect of paper constituents on fungal growth and their sporulating ability.     

KMS States, Entropy and the Variational Principle¶in Full C*-Dynamical Systems

To any periodic and full C ^*-dynamical system , an invertible operator s acting on the Banach space of trace functionals of the fixed point algebra is canonically associated. KMS states correspond to positive eigenvectors of s. A Perron–Frobenius type theorem asserts the existence of KMS states at inverse temperatures equals the logarithms of the inner and outer spectral radii of s (extremal KMS states). Examples arising from subshifts in symbolic dynamics, self-similar sets in fractal geometry and noncommutative metric spaces are discussed. Certain subshifts are naturally associated to the system, and criteria for the equality of their topological entropy and inverse temperatures of extremal KMS states are given. Unital completely positive maps implemented by partitions of unity {x _j } of grade 1 are considered, resembling the “canonical endomorphism” of the Cuntz algebras. The relationship between the Voiculescu topological entropy of and the topological entropy of the associated subshift is studied. Examples where the equality holds are discussed among Matsumoto algebras associated to non finite type subshifts. In the general case is bounded by the sum of the entropy of the subshift and a suitable entropic quantity of the homogeneous subalgebra. Both summands are necessary. The measure-theoretic entropy of , in the sense of Connes–Narnhofer–Thirring, is compared to the classical measure-theoretic entropy of the subshift. A noncommutative analogue of the classical variational principle for the entropy is obtained for the “canonical endomorphism” of certain Matsumoto algebras. More generally, a necessary condition is discussed. In the case of Cuntz–Krieger algebras an explicit construction of the state with maximal entropy from the unique KMS state is done. Received: 1 February 2000 / Accepted: 23 February 2000     

One-step incorporation of Pd-Zn catalytic sites into organized mesoporous alumina for use in the oxidative steam reforming of methanol

In this paper we report the preparation of an organized mesoporous Pd-Zn/alumina system, by a new surfactant-assisted single-step sol-gel synthesis, performed in alcohol, using stearic acid as a chemical template, aluminum sec-butoxide as Al source and metal stearates both as Pd-Zn sources and as structural directing agents. The prepared materials have been characterized using a variety of techniques such as thermogravimetric analysis, atomic absorption spectroscopy, X-ray powder diffraction and N2 adsorption-desorption, and preliminarily tested in the oxidative steam reforming of methanol (OSRM) in the temperature range 100-400 degrees C.     

Surface modifications of carbide ceramics induced by pulsed laser treatments

It is well known that sintered ceramics are very hard and difficult materials to process and machine by traditional methods. An easy and available solution seems to be a pulsed laser treatment, under appropriate experimental conditions (pulse duration and energy, radiation incidence angle, working atmospheres, etc.). In these experiments, in order to modify the structure and morphology of the surface, polycrystalline sintered SiC substrates were irradiated with an ArF (5=193 nm,h9=6.4 eV,F=30 ns) pulsed laser, at different fluences and at grazing incidence angle. Since it is well known that laser irradiation can produce both a dissociation of surface compounds and a high level of amorphisation (owing to very rapid cooling of melted material) different working atmospheres (Ar or O₂ or CH₄) and substrate heating (~700 °C) have been used, with the aim of confining and controlling any chemical and physical transformation produced by laser-material interaction. Morphological and structural modifications have been studied by SEM/EDAX microscopy. Surface chemistry has been analysed by Raman spectroscopy. Changes in surface roughness have also been quantified by AFM microscopy.     

The planetary <Emphasis Type="Italic">N</Emphasis>-body problem: symplectic foliation,reductions and invariant tori

This is the third of a series of papers relating intersections of special cycles on the integral model of a Shimura surface to Fourier coefficients of Hilbert modular forms. More precisely, we embed the Shimura curve over ℚ associated to a rational quaternion algebra into the Shimura surface associated to the base change of the quaternion algebra to a real quadratic field. After extending the associated moduli problems over ℤ we obtain an arithmetic threefold with a embedded arithmetic surface, which we view as a cycle of codimension one. We then construct a family, indexed by totally positive algebraic integers in the real quadratic field, of codimension two cycles (complex multiplication points) on the arithmetic threefold. The intersection multiplicities of the codimension two cycles with the fixed codimension one cycle are shown to agree with the Fourier coefficients of a (very particular) Hilbert modular form of weight 3/2. The results are higher dimensional variants of results of Kudla-Rapoport-Yang, which relate intersection multiplicities of special cycles on the integral model of a Shimura curve to Fourier coefficients of a modular form in two variables.     

The Indian drawings of the poet Cesare Pascarella: non-destructive analyses and conservation treatments

The Italian dialect poet Cesare Pascarella travelled all around the world, noting down in notebooks his keen and caustic observations, and drawing sketches that are a visual reportage of his journeys. The sketches were mounted as a random collage over acidic cardboards that were exposed to direct sunlight in his studio. Their poor state of conservation is related to the use of modern paper: chemical instability of raw materials caused acidification and strong oxidation of the support, with intense yellowing of the surfaces and brittleness of the paper. To ensure future preservation of the drawings, chemical stabilisation with simultaneous alcoholic treatment by deacidification (calcium propionate) and reduction (borane tert-butylamine complex) appeared necessary. To verify its applicability, it was indispensible to characterise the support and identify the nature of all the graphic media. The use of Raman, Infrared, X-ray fluorescence spectroscopies and scanning electron microscopy coupled with X-ray microanalysis allowed us to clear the problems related to the different penetration depth of each analytical technique and the different responses of pigments/dyes to each spectroscopy. The palette, how it varied along the journeys, the different supports used and preparations were completely identified showing a choice of colours compatible with the reduction treatment.