Sergio Mascarenhas

Quality assessment of coffee beans with ESR and Gamma-ray irradiation

Peroxy radical formation in raw coffee beans of different qualities and origins from all over the world has been studied with electron spin resonance (ESR) analysis. The gamma-ray equivalent absorbed dose (ED) which creates the same concentration of radicals is obtained by the additive gamma-ray irradiation of the coffee beans. The ED and the cup quality is somewhat inversely related suggesting that the peroxidation of the unsaturated fatty acid is somewhat indicative of the degree of the aromatic decomposition and rancidity.

Electrets in biophysics

Abstract The electric behaviour of biomaterials, such as artificial polymers used in biomedical applications as well as naturally occurring biopolymers, is discussed. The electret behaviour of so-called biowater (structured water) is also described. The general occurrence of the electret state in proteins, polynucleotides, polysaccharides, and its possible meaning for biophysical phenomena in membranes, enzymes and biological growth mediation is reviewed. The term bioelectret is proposed.

Systems Biology: an information-theoretic-based thermo-statistical approach

Systems Biology (system-level understanding in biological science), from the physical-chemical point of view, is involved with irreversible thermodynamics and nonlinear kinetic theory of open systems which are founded on nonequilibrium statistical mechanics. We describe a modern thermo-statistical approach for dealing with complex systems, in particular biological systems. We consider the case of a very peculiar complex behavior in open boson systems sufficiently away, from equilibrium, which appear to have large relevance in the functioning of biological systems. This is, on the one hand, the so-called Frohlich-Bose-Einstein-like condensation leading in steady-state conditions to the emergence of a particular case of quantum-large-scale coherent ordering, of the type of a selforganizing-synergetic dissipative structure. Moreover, additional complexity emerges in the form of propagation, in this condensate, of signals (information) consisting of nearly undamped and undistorted, long-distance propagating, solitary waves (the pseudoparticle soliton). It can be accompanied by a so-called Frohlich-Cherenkov cone of emission of polar vibrations, and it is also possible the formation of ¨ metastable states of the form of the so-called bioelectrets. These are phenomena apparently working in biological processes, which are presently gaining relevant status on the basis of eventually providing a large-scale quantum-coherent behavior in cytoskeletons of neurons and the conscious (non-computational) activity in the brain. Emphasis is centered on the quantum-mechanical-statistical irreversible thermodynamics of these open systems, and the informational characteristics of the phenomena. Ways for their experimental evidencing are pointed out and discussed.

Prospective study on non-invasive assessment of ICP in head injured patients: comparison of four methods

DC is supported by a Cambridge Commonwealth, European & International Trust Scholarship, University of Cambridge. JD is supported by a Woolf Fisher Trust Scholarship. XL is supported by a Gates Cambridge Scholarship. GVV is supported by an A. G. Leventis Foundation Scholarship, and a Charter Studentship from St Edmund’s College, Cambridge. SM and GF are supported by the Pan-American Health Organization. DC and MC are partially supported by NIHR Brain Injury Healthcare Technology Co-operative, Cambridge, UK.

Bernhard Gross and his contribution to physics in Brazil

Most of the following lines were originally written in 1985-1986 [1]; now in 1998, on the invitation of R. Gerhard-Multhaupt, G. F. Leal Ferreira, and R. M. Faria, I have the honor to write another contribution about Bernhard Gross, this time for a special issue of the Brazilian Journal of Physics dedicated to him. Between 1985 and 1998, Professor Gross has again accomplished a number of marvelous scienti c results: Besides other things, he supervised three Ph.D. theses and published a total of nineteen papers in well-known international journals. He also initiated other new lines of research as dynamical methods for the investigation of electron emission from metal or polymer surfaces and for the experimental study of electrical e ects in solid dielectrics upon low-energy electron irradiation, besides several theoretical contributions with his close friend, colleague, and neighbor Guilherme Leal Ferreira. Incidentally, the friendship or, best put, the love, which permeates the Bernhard Gross Electrets and Polymers Laboratory in S~ao Carlos and which was induced by Bernhard Gross himself, is a magni cent example of how science can (and should!) be cultivated together with humanity.

Validation of a New Minimally Invasive Intracranial Pressure Monitoring Method by Direct Comparison with an Invasive Technique

In this chapter we present in vivo experiments with a new minimally invasive method of monitoring intracranial pressure (ICP). Strain gauge deformation sensors are externally glued onto the exposed skull. The signal from these sensors is amplified, filtered, and sent to a computer with appropriate software for analysis and data storage. Saline infusions into the spinal channel of rats were performed to produce ICP changes, and minimally invasive ICP and direct Codman intraparenchymal ICP were simultaneously acquired in six animals. The similarity between the invasive and minimally invasive methods in response to ICP increase was assessed using Pearsons correlation coefficient. It demonstrated good agreement between the two measures < r > = 0.8 ± 0.2, with a range of 0.31-0.99.

Characterization of Intracranial Pressure Behavior in Chronic Epileptic Animals: A Preliminary Study

Intracranial pressure (ICP) is a major neurological parameter in animals and humans. ICP is a function of the relationship between the contents of the cranium (brain parenchyma, cerebrospinal fluid, and blood) and the volume of the skull. Increased ICP can cause serious physiological effects or even death in patients who do not quickly receive proper care, which includes ICP monitoring. Epilepsies are a set of central nervous system disorders resulting from abnormal and excessive neuronal discharges, usually associated with hypersynchronism and/or hyperexcitability. Temporal lobe epilepsy (TLE) is one of the most common forms of epilepsy and is also refractory to medication. ICP characteristics of subjects with epilepsy have not been elucidated because there are few studies associating these two important neurological factors. In this work, an invasive (ICPi) and the new minimally invasive (ICPmi) methods were used to evaluate ICP features in rats with chronic epilepsy, induced by the experimental model of pilocarpine, capable of generating the main features of human TLE in these animals.

Fröhlich Condensate: Emergence of Synergetic Dissipative Structures in Information Processing Biological and Condensed Matter Systems

We consider the case of a peculiar complex behavior in open boson systems sufficiently away from equilibrium, having relevance in the functioning of information-processing biological and condensed matter systems. This is the so-called Frohlich–Bose–Einstein condensation, a self-organizing-synergetic dissipative structure, a phenomenon apparently working in biological processes and present in several cases of systems of boson-like quasi-particles in condensed inorganic matter. Emphasis is centered on the quantum-mechanical-statistical irreversible thermodynamics of these open systems, and the informational characteristics of the phenomena.