Aneurysms of the intracranial segment of the ophthalmic artery trunk. case report and systematic literature review

Aneurysms arising from the ophthalmic artery trunk (OAT) are very rare, particularly in the artery's intracranial course. The onset of a subarachnoid hemorrhage (SAH) from a ruptured OAT aneurysm in this segment is extremely rare. We present a case and discuss the anatomy, clinical significance, and therapeutic options for an aneurysm at this site. We also retrospectively analyzed the record of a patient with a ruptured aneurysm of the intracranial segment of the OAT and conducted a comprehensive and systematic review of the PubMed and Scopus databases for literature on this pathology. Only one case report of SAH from an aneurysm of the intracranial segment of the OAT was published in the literature. Only in our case was the intracranial OAT segment aneurysm discovered in the acute phase of SAH. Conventional angiography with three-dimensional acquisition may help detect aneurysms at this level. Detailed knowledge of the anatomy of the OAT is of paramount importance for both surgical and endovascular approaches. Surgical treatment is complex because of difficulties in accessing the orbital region and the risk of optic nerve and vascular injuries. Endovascular treatment, when feasible, could be a good alternative to reduce the risk of loss of vision related to surgical manipulation

Advanced radar absorbing ceramic-based materials for multifunctional applications in space environment

In this review, some results of the experimental activity carried out by the authors on advanced composite materials for space applications are reported. Composites are widely employed in the aerospace industry thanks to their lightweight and advanced thermo-mechanical and electrical properties. A critical issue to tackle using engineered materials for space activities is providing two or more specific functionalities by means of single items/components. In this scenario, carbon-based composites are believed to be ideal candidates for the forthcoming development of aerospace research and space missions, since a widespread variety of multi-functional structures are allowed by employing these materials. The research results described here suggest that hybrid ceramic/polymeric structures could be employed as spacecraft-specific subsystems in order to ensure extreme temperature withstanding and electromagnetic shielding behavior simultaneously. The morphological and thermo-mechanical analysis of carbon/carbon (C/C) three-dimensional (3D) shell prototypes is reported; then, the microwave characterization of multilayered carbon-filled micro-/nano-composite panels is described. Finally, the possibility of combining the C/C bulk with a carbon-reinforced skin in a synergic arrangement is discussed, with the aid of numerical and experimental analyses

Anomalous kinetics and transport from 1D self--consistent mode--coupling theory

We study the dynamics of long-wavelength fluctuations in one-dimensional (1D) many-particle systems as described by self-consistent mode-coupling theory. The corresponding nonlinear integro-differential equations for the relevant correlators are solved analytically and checked numerically. In particular, we find that the memory functions exhibit a power-law decay accompanied by relatively fast oscillations. Furthermore, the scaling behaviour and, correspondingly, the universality class depends on the order of the leading nonlinear term. In the cubic case, both viscosity and thermal conductivity diverge in the thermodynamic limit. In the quartic case, a faster decay of the memory functions leads to a finite viscosity, while thermal conductivity exhibits an even faster divergence. Finally, our analysis puts on a more firm basis the previously conjectured connection between anomalous heat conductivity and anomalous diffusion

Effects of atomic oxygen and UV rays ageing on the reflection coefficient of carbon/carbon plates in the 12-18 GHz frequency range

Advanced carbon-based ceramic materials, such as Carbon/Carbon (C/C) are commonly employed in aerospace industry to face the thermo-mechanical stress suffered by the spacecraft external structures during re-entry in earth atmosphere. Thanks to very low thermal expansion and outstanding chemical stability at extreme temperatures, in fact, such materials represent the ideal candidates for re-usable space integrated systems, such as TPS, nozzles and ablation thermal-proof structures. In long-time missions, on the other hand, issues related to continuous and extended exposure of the spacecraft surfaces to the detrimental space environment must be carefully considered. In this frame, also the tracking of satellites by mean of radar systems is a vital aspect for a safe stay in space. In LEO working conditions, the combined effects induced by severe thermal cycles, ultra-high vacuum and UV/Atomic Oxygen(AO) irradiation can be of impediment for the use of C/C as re-entry protection material, since a significant surface oxidation leads to so high TPS damaging as to compromise its main functionality. This surface oxidation can also affect the radar visibility of satellites. Aim of this paper is to evaluate the effects of the AO/UV ageing on C/C plates reflection coefficient, in order to avoid misfunctioning in the radar visibility

Nonequilibrium dynamics of a stochastic model of anomalous heat transport

We study the dynamics of covariances in a chain of harmonic oscillators with conservative noise in contact with two stochastic Langevin heat baths. The noise amounts to random collisions between nearest-neighbour oscillators that exchange their momenta. In a recent paper, [S Lepri et al. J. Phys. A: Math. Theor. 42 (2009) 025001], we have studied the stationary state of this system with fixed boundary conditions, finding analytical exact expressions for the temperature profile and the heat current in the thermodynamic (continuum) limit. In this paper we extend the analysis to the evolution of the covariance matrix and to generic boundary conditions. Our main purpose is to construct a hydrodynamic description of the relaxation to the stationary state, starting from the exact equations governing the evolution of the correlation matrix. We identify and adiabatically eliminate the fast variables, arriving at a continuity equation for the temperature profile T(y,t), complemented by an ordinary equation that accounts for the evolution in the bulk. Altogether, we find that the evolution of T(y,t) is the result of fractional diffusion.Comment: Submitted to Journal of Physics A, Mathematical and Theoretica

Simulation of heat transport in low-dimensional oscillator lattices

The study of heat transport in low-dimensional oscillator lattices presents a formidable challenge. Theoretical efforts have been made trying to reveal the underlying mechanism of diversified heat transport behaviors. In lack of a unified rigorous treatment, approximate theories often may embody controversial predictions. It is therefore of ultimate importance that one can rely on numerical simulations in the investigation of heat transfer processes in low-dimensional lattices. The simulation of heat transport using the non-equilibrium heat bath method and the Green-Kubo method will be introduced. It is found that one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) momentum-conserving nonlinear lattices display power-law divergent, logarithmic divergent and constant thermal conductivities, respectively. Next, a novel diffusion method is also introduced. The heat diffusion theory connects the energy diffusion and heat conduction in a straightforward manner. This enables one to use the diffusion method to investigate the objective of heat transport. In addition, it contains fundamental information about the heat transport process which cannot readily be gathered otherwise.Comment: Article published in: Thermal transport in low dimensions: From statistical physics to nanoscale heat transfer, S. Lepri, ed. Lecture Notes in Physics, vol. 921, pp. 239 - 274, Springer-Verlag, Berlin, Heidelberg, New York (2016

Production of benzaldehyde, benzyl alcohol and benzoic acid by yeasts and Botrytis cinerea isolated from grape musts and wines

The capacity of 100 yeast strains - isolated from grape musts and wines from the Istituto Sperimentale per l'Enologia collection - to produce benzaldehyde, benzyl alcohol and benzoic acid was verified by inoculation into a synthetic nutrient medium (MNS). Schizosaccharomyces and Zygosaccharomyces were strongest in producing benzaldehyde (maximal amount found 1200 µg/l) and benzyl alcohol (maximally 523 µg/l). Zygosaccharomyces was also most effective in the production of benzoic acid (maximally 536 µg/l), followed by Saccharomyces, Cryptococcus, Kloeckera and Torulaspora. The hypothesis was verified that yeasts can be an exogenous source of the benzyl alcohol oxidizing enzyme in grape musts and wines. Wine yeast strains of Saccharomyces spp., Zygosaccharomyces spp. and Schizosaccharomyces spp. fermenting MNS containing 150 g/l glucose, with benzyl alcohol added, transformed this into benzoic acid only when glucose was disappearing, but not into benzaldehyde. No difference was observed between aerobic and anaerobic fermentation conditions. The uptake of benzyl alcohol was rapid in fermentation essays in presence of only 10 g/l glucose and in assimilation essais performed in yeast nitrogen base broth with assimilable carbon compounds added. A catabolic repression by glucose appears likely. Botrytis cinerea was able to transform benzyl alcohol into benzaldehyde and benzoic acid on Czapek-Dox broth with 30 g/l sucrose added. Benzyl alcohol was transformed by wine yeasts into benzoic acid when the concentration of glucose in the mineral medium was less than 10 g/l, but no production of benzaldehyde was observed. A catabolic repression of this transformation by glucose is likely. Botrytis cinerea was able to produce benzaldehyde in a mineral medium with benzyl alcohol and sucrose added

Ruptured Brain Arteriovenous Malformations: Surgical Timing and Outcomes-A Retrospective Study of 25 Cases

Background One important problem in treatment of ruptured brain arteriovenous malformations (bAVMs) is surgical timing. The aim of the study was to understand which parameters affect surgical timing and outcomes the most. Materials and Methods Between January 2010 and December 2018, 25patients underwent surgery for a ruptured bAVM at our institute. Intracerebral hemorrhage (ICH) score was used to evaluate hemorrhage severity, while Spetzler-Martin scale for AVM architecture. We divided patients in two groups: early surgery and delayed surgery. The modified Rankin Scale (mRS) evaluated the outcomes. Results Eleven patients were in the early surgery group: age 38 ± 18 years, Glasgow Coma Scale (GCS) 7.64 ± 2.86, ICH score 2.82 ± 0.71, hematoma volume 45.55 ± 23.21 mL. Infratentorial origin of hemorrhage was found in 27.3% cases; AVM grades were I to II in 82%, III in 9%, and IV in 9% cases. Outcome at 3 months was favorable in 36.4% cases and in 54.5% after 1 year. Fourteen patients were in the delayed surgery group: age 41 ± 16 years, GCS 13.21 ± 2.39, ICH score 1.14 ± 0.81, hematoma volume 29.89 ± 21.33 mL. Infratentorial origin of hemorrhage was found in 14.2% cases; AVM grades were I to II in 50% and III in 50%. Outcome at 3 months was favorable in 78.6% cases and in 92.8% after 1 year. Conclusions The early outcome is influenced more by the ICH score, while the delayed outcome by Spetzler-Martin grading. These results suggest that it is better to perform surgery after a rest period, away from the hemorrhage when possible. Moreover, this study suggests how in young patient with a high ICH score and a low AVM grade, early surgery seems to be a valid and feasible therapeutic strategy

Can the electronic nose diagnose cronic rhinosinusitis? A new experimental study

In otorhinolaryngologist's experience the nasal out-breath of people affected by chronic nasal or paranasal infections may be characterized by peculiar odours. In a previous study we showed that an electronic nose (EN), examining nasal out breath was able to distinguish subjects affected by chronic rhinosinusitis from healthy subjects. The present study is aimed at analysing the intensity and the quality of the odorous components present in the air expired by patients affected by rhinosinusitis, using a new EN based on gas-chromatography and surface acoustic wave analysis. In the gas-chromatographic tracings of the pathologic subjects there were six peaks, which were not present in control group cases. These peaks correspond to odorous components, whose chemical composition ranges from C6 to C14. Peaks obtained were compaired with other tracings revealed from specific bacterial and fungal cultures analyses and we appreciated some analogies