Sensitivity of coherent anti-Stokes Raman lineshape to time asymmetry of laser pulses

We show that coherent anti-Stokes Raman lineshapes do not follow known spectral profiles if the time asymmetry of realistic laser pulses is taken into account. Examples are given for nanosecond and picosecond laser pulses commonly employed in frequency-resolved coherent anti-Stokes Raman scattering. More remarkably, the analysis suggests an effect of line narrowing in comparison to the customary approach, based primarily on the Voigt lineshape.Comment: 8 pages, 3 short sections, 4 figure

Hybrid P2P Architecture for Transaction Management

In contrast with many centralised schemes P2P systems are flexible, scalable and highly dynamic. They offer an attractive distributed platform despite concerns over security. This work is motivated by the need to address explicitly the main issues that arise in the deployment of P2P systems in a business environment. A systematic approach is proposed in the development of a secure and trusted system to support authentication, non-repudiation and trust in business transactions. This involves two stages. Firstly, the identification of the functional components designed to facilitate security through authentication and nonrepudiation, and those aimed at insuring trust; secondly, their implementation and integration into a hybrid P2P architecture, where the entry point server plays a central role. This integration is facilitated by the layering of functional components. Secure and trusted file transactions are further enhanced by a community management layer

Measurement and clinical significance of biomarkers of oxidative stress in humans

Oxidative stress is the result of the imbalance between reactive oxygen species (ROS) formation and enzymatic and nonenzymatic antioxidants. Biomarkers of oxidative stress are relevant in the evaluation of the disease status and of the health-enhancing effects of antioxidants. We aim to discuss the major methodological bias of methods used for the evaluation of oxidative stress in humans. There is a lack of consensus concerning the validation, standardization, and reproducibility of methods for the measurement of the following: (1) ROS in leukocytes and platelets by flow cytometry, (2) markers based on ROS-induced modifications of lipids, DNA, and proteins, (3) enzymatic players of redox status, and (4) total antioxidant capacity of human body fluids. It has been suggested that the bias of each method could be overcome by using indexes of oxidative stress that include more than one marker. However, the choice of the markers considered in the global index should be dictated by the aim of the study and its design, as well as by the clinical relevance in the selected subjects. In conclusion, the clinical significance of biomarkers of oxidative stress in humans must come from a critical analysis of the markers that should give an overall index of redox status in particular conditions

Ancient Schwannoma of the Cauda Equina: our experience and review of the literature

Ancient schwannomas (AS) are exceedingly rare variant of common schwannomas (CS). Only two cases involving the cauda equina region have been previously reported in literature. AS are typically associated with a higher histological degree of degenerative changes (Antoni B areas). It is of peculiar importance, according to our opinion, to outline that, because of their extremely slow growth (which explains the increase of the degenerative changes in respect to the CS) and their typical soft consistency in respect to their standard counterparts, AS usually imply an even better prognosis

Meandered-slot antennas for sensor-RFID tags

This letter introduces a planar antenna layout suited to Sensor-RFID fabrication. The geometry is based on a meandered-slot profile on a suspended patch and permits to host sensors and electronics in a small space. The available geometrical parameters are optimized by means of a Genetic Algorithm (GA) procedure aimed to maximize the antenna realized gain. The antenna performances are discussed through examples and prototypes