Abstract

Abstract
Optical coherence tomography is nowadays an established imaging technique in Ophthalmology, with a key role on early detection of macular diseases, benefiting from the tremendous evolution in principles and technological developments of the last 20 years. In this paper the most important physical principles behind time-domain, spectral-domain and Fourier-domain OCT will be presented, along with examples of applications in different imaging fields, emphasizing the limitations of current systems, their performance parameters, as well as the challenges for the future within this field of development.

Abstract
We discuss a mechanism of generating two separable beams of light with a high degree of entanglement in momentum using a fast and sharp optical boundary. Three regimes of light generation are identified depending on the number of resonant interactions between the optical perturbation and the electromagnetic field. The intensity of the process is discussed in terms of the relevant physical parameters: variation of refractive index and apparent velocity of the optical boundary. Our results suggest a different class of generation entangled light that is robust against thermal degradation by exciting zero point fluctuations using parametric resonant optical modulations.

Abstract
We report results of a search for light (less than or similar to 10 GeV) particle dark matter with the XENON10 detector. The event trigger was sensitive to a single electron, with the analysis threshold of 5 electrons corresponding to 1.4 keV nuclear recoil energy. Considering spin-independent dark matter-nucleon scattering, we exclude cross sections sigma(n) > 7 x 10(-42) cm(2), for a dark matter particle mass m(chi) = 7 GeV. We find that our data strongly constrain recent elastic dark matter interpretations of excess low-energy events observed by CoGeNT and CRESST-II, as well as the DAMA annual modulation signal.

Abstract
XENON10 is the first two-phase xenon time projection chamber (TPC) developed within the XENON dark matter search program. The TPC, with an active liquid xenon (LXe) mass of about 14 kg, was installed at the Gran Sasso Underground Laboratory (LNGS) in Italy, and operated for more than one year, with excellent stability and performance. Results from a dark matter search with XENON10 have been published elsewhere. In this paper, we summarize the design and performance of the detector and its subsystems, based on calibration data using sources of gamma-rays and neutrons as well as background and Monte Carlo simulation data. The results on the detector's energy threshold, position resolution, and overall efficiency show a performance that exceeds design specifications, in view of the very low energy threshold achieved (< 10 keVr) and low background rate achieved.

Abstract
An ultrasonic assisted solid-liquid extraction method was developed to determine the level of lead in the brain and urine of rats. Lead was determined by electrothermal atomic absorption spectrometry with longitudinal-Zeeman background correction. Several analytical drawbacks were addressed and overcome, namely small brain sample mass and the formation of precipitate in the urine samples. Utrasonication provided by an ultrasonic probe succeeded in extracting lead from brain samples. Furthermore, it was demonstrated that the formation of a precipitate lowered the lead content in the liquid phase of the urine. Lead was back extracted from the precipitate to the liquid phase with the aid of ultrasonic energy and acidifying the urine with 10% v/v nitric acid. A microwave-assisted acid digestion protocol was used to check the completeness of the lead extraction. The within bath and between bath precision was 5% (n = 9) and 7% (n = 3) respectively. The limit of quantification was 1.05 mu g g(-1) for brain samples and 2.1 mu g L(-1) for urine samples. A total of 6 samples of urine and 12 samples of brain from control rats and another 6 samples of urine and 12 samples of brain from rats fed with tap water rich in lead acetate were used in this research. Lead levels in brain and urine from exposed rats ranged from 1.9 +/- 0.2 mu g g(-1) to 3.5 +/- 0.2 mu g g(-1) and from 752 +/- 56 mu g L(-1) to 60.9 +/- 1.2 mg L(-1) respectively. Statistically significant differences of levels of lead in brain and urine were found between exposed and non exposed rats.