A study of visible laser ablation of tantalum in vacuum by using 3ns Nd:YAG laser radiation at high pulse energy is reported. Nanosecond pulsed ablation, at an intensity on the order of 109W∕cm2, produces high nonisotropic emission of neutrals and ionic species. Mass quadrupole spectrometry, coupled to electrostatic ion deflection, allows estimation of the energy distributions of the emitted species within the plume as a function of the incident laser energy. Neutrals show typical Boltzmann distributions while ions show Coulomb-Boltzmann-shifted distributions depending on their charge state. Surface profiles of the craters and microscopy investigations permitted to study the ablation threshold, ablation yields, and deposition rates of thin films on silicon substrates. The multicomponent structure of the plume emission is rationalized in terms of charge state, ion and neutral equivalent temperatures, and plasma density. A special regard is given to the ion acceleration process occurring inside the plasma due to the high electrical field generated at the nonequilibrium plasma conditions. The angular distributions of the neutral and ion species are also presented and discussed.

Different multivariate techniques were tested in an attempt to build up a statistical model for predicting the origin of prickly pears (Opuntia ficus-indica L., cv. Muscaredda) from several localities within the Sicilian region. Specifically, two areas known for producing fruits marked respectively by TAP (traditional agri-food product) and PDO (protected designation of origin) brands, and three sites producing non-branded fruits, were considered. A validated inductively coupled plasma mass spectrometry (ICP-MS) method allowed to obtain elemental fingerprints of prickly pears, which were subsequently elaborated by unsupervised tools, such as hierarchical clustering analysis (HCA) and principal component analysis (PCA), and supervised techniques, such as stepwise-canonical discriminant analysis (CDA) and partial least squares-discriminant analysis (PLS-DA). With the exception of HCA, which was not enough powerful to correctly cluster all selected samples, PCA successfully investigated the effect of subregional provenance on prickly pears, thus, differentiating labeled products from the non-labeled counterpart. Also, stepwise CDA and PLS-DA allowed to build up reliable models able to correctly classify 100% of fruits on the basis of the production areas, by exploiting a restricted pool of metals. Both statistical models, including unsupervised (PCA) and supervised techniques (stepwise CDA or PLS-DA), may guarantee the provenance of prickly pears protected by quality labels and safeguard producers and consumers.Practical Application: Based on elemental analysis and chemometrics, the reliable traceability models herein proposed, could be applied to commercial Sicilian prickly pears protected by TAP and PDO logos to guarantee their provenance and, at the same time, to safeguard producers and consumers.

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The aim of this study is to evaluate the difference in the number of endothelial cells after cataract operations with phacoemulsification by using a balanced salt solution (BSS) at standard temperature (about 20 °C) and at 2.7 °C. Two groups, comprising 214 individuals in total, participated in this study; patients were operated on using BSS bottle at about 20 °C and 2.7 °C in the first and second groups, respectively. All operations were conducted by the same surgeon and in similar conditions. One month after the operations, endothelial cells in the two groups were checked. For patients in Group 2, an important reduction in the loss of endothelial cells was observed.