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INTRODUCTION/OBJECTIVES: Several reports have assessed clinical significance of diminutive (1-5 mm) polyps; here we report on the prevalence of advanced histology in patient with "isolated" diminutive polyps, i.e. without associated polyps of larger size. AIMS & METHODS: Retrospective examination of endoscopy records and of histopathology records of patients with polyps of any size. Advanced histology was defined as the presence of high grade dysplasia (HGD) or in situ carcinoma. Polyps were categorized into three groups: diminutive (1-5 mm); small (6-10 mm) and large (11 mm or more). Diminutive Small Large Advanced Carcinoma Number 315 89 67 84 Male (%) 205 (62) 57 (64) 46 (68) 52 (62) Mean age 62.0 67.2 68.7 70.1 % HGD 0.9 11.2 32.8 Not appropriated RESULTS: Data on 2176 consecutive colonoscopies were evaluated; biopsies were performed in 895 (41%); 555 (61%) biopsies evaluated polyps of various size; 315 patients (61%) showed "isolated" diminutive polyps, 89 (16%) patients had small polyps and 67 (12%) had large polyps. Advanced carcinoma was present in 84 (15%) patients. Mean age and prevalence of high grade dysplasia are shown in the table. CONCLUSION: "Isolated" diminutive polyps are at very low risk of advanced histology; small polyps carry a significant risk of advanced histological features. Difference in mean age between groups at different risk of HGD and with patients with advanced carcinoma suggests that progression from diminutive polyps to polyps of larger size and with significant HGD risk might need several (5 or 6) years.

INTRODUCTION/OBJECTIVES: Current recommendations on post-polypectomy surveillance recommend shorter intervals in case of 3 or more polyps, irrespectively of histological findings (see reference below). These recommendations doesn't differentiate between diminutive (1-5 mm) polyps and polyps of larger size (>5 mm). AIMS & METHODS: Aim of the present study was to assess, in a group of patients with "isolated" diminutive polyps, i.e. without associated polyps of larger size, if the presence of 3 or more diminutive polyps is associated with higher number of polyps with villous histology (VH) or high grade dysplasia (HGD). Retrospective examination of endoscopical records and of histopathological records of patients with diminutive polyps. RESULTS: 315 patients with "isolated" diminutive polyps were identified; 171 patients showed neoplastic (i.e.adenomatous) histology, while remaining showed hyperplastic histology or absence of polypoid features at histology. Data on prevalence of villous component at histology according to number of polyps detected are shown in the table. N° of patients VH HGD TOT N° of polyps (%) 1 polyp 97 6 1 7 (7.2) 97 2 polyps 43 9 0 9 (20.5) 86 >2 polyps 31 1 0 1 (3.0) 112 Prevalence of villous histology or HGD according to number of diminutive polyps was 16/140 (11.4%) in patients with one or two diminutive polyps and 1 /112 (0.8%) in patients with 3 or more polyps. CONCLUSION: Number of diminutive polyps found in a single patient does not seem to affect risk of villous histology or high grade dysplasia in diminutive polyps. Further studies are needed to assess if current recommendations on 3-year intervals of surveillance for patients with 3 or more polyps can apply to patients with "isolated" diminutive polyps.

Espoo-Helsinki (Finland)

26th European Photovoltaic Solar Energy Conference and Exhibition; 681-685, In this paper the designs, realization and indoor and outdoor experimental results of a laboratory test facility system for Concentrator Photovoltaic Receivers (CPR) characterization are reported. In particular, the proposed system has been developed in order to perform tests on CPRs characterized by high geometrical concentration factor (Cgeo). The test facility system is devoted to verify and qualify the behavior of CPR from different points of view. The system design has been developed paying particular attention to the test bench used for the evaluation of I-V characteristics of concentrator solar cells under high geometrical concentration factors. The preliminary study activity has been focused on the irradiance level, light source spectral composition, exposition time and operation temperature dependences of CPR characterization process. The main purpose of this research is to propose in the next future novel tests to qualify the CPR system for a long-time operation (Light-Soaking and/or Hot-spot endurance tests). To execute measurements in a wide range of concentration, an opto-mechanical system for continuous light solar simulator coupling has been designed. The realized prototype produces a maximal geometrical concentration factor equal or less than 900x for testing Solar cells of an active area of 1 cm².

In the paper an interleaved soft switching dc-dc converter for applications in electric vehicle is proposed. The used topology raises the efficiency and the power density of the dc/dc converter minimizing switching losses by adopting a simple auxiliary active clamping circuit. Such auxiliary circuit is operational regardless of boost or buck mode of operation. The configuration guarantees fixed switching frequency, active clamped zero voltage switching operations of the main switches and bidirectional power flow. ZVS operations are guaranteed with wide load range. In the paper the operating principle, soft-switching conditions and steady state analysis are presented. A 27 kW prototype is designed and simulation results to verify the theoretical analysis are provided.

25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 906-909, In this paper we present our first results regarding the development of a Concentrating Photovoltaic (CPV) systems based on a classical Cassegrain optical design and a beam homogenizer. The system is characterized by a geometrical concentration factor (Cgeo) of around 500X. The optical design has been developed in order to obtain a 10 mm wide square image. Particular attention has been devoted to the homogenizer and to its building materials in order to reduce the cost and the thermal effects caused by concentrated radiation. Moreover the optical design has been specifically chosen to produce a Sun square image that optimizes the pv cell coupling. The field of view (FOV) of the designed concentrator is of +/- 0.5 degrees. The primary mirror has a 220 mm wide square aperture and a focal length of 80 mm (f/0.4). The secondary mirror is hyperbolic with a magnification of 6X that lead to a 4 mm diameter Sun image. In order to obtain a 10 mm wide square image, we used a total internal reflection (TIR) homogenizer. In this way the focal plane may host a typical commercial triple junction PV receiver assembly with a 10 mm squared active area. Cells of different sizes may be easily fitted by changing the exit side dimension of the homogenizer. The optical design has been optimized and it is ready for the test and optical characterization.

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During summer 2006 a fraction of the CMS silicon strip tracker was operated in a comprehensive slice test called the Magnet Test and Cosmic Challenge (MTCC). At the MTCC, cosmic rays detected in the muon chambers were used to trigger the readout of all CMS sub-detectors in the general data acquisition system and in the presence of the 4 T magnetic field produced by the CMS superconducting solenoid. This document describes the operation of the Tracker hardware and software prior, during and after data taking. The performance of the detector as resulting from the MTCC data analysis is also presented.

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