positive predictive value for malignancy on surgical excision of breast lesions of uncertain malignant potential b3 diagnosed by stereotactic vacuum assisted needle core biopsy vancb a large multi institutional study in italy

Abstract Percutaneous core biopsy (CB) has been introduced to increase the ability of accurately diagnosing breast malignancies without the need of resorting to surgery. Compared to conventional automated 14 gauge needle core biopsy (NCB), vacuum-assisted needle core biopsy (VANCB) allows obtaining larger specimens and has recognized advantages particularly when the radiological pattern is represented by microcalcifications. Regardless of technical improvements, a small percentage of percutaneous CBs performed to detect breast lesions are still classified, according to European and UK guidelines, in the borderline B3 category, including a group of heterogeneous lesions with uncertain malignant potential. We aimed to assess the prevalence and positive predictive values (PPV) on surgical excision (SE) of B3 category (overall and by sub-categories) in a large series of non-palpable breast lesions assessed through VANCB, also comparison with published data on CB. Overall, 26,165 consecutive stereotactic VANCB were identified in 22 Italian centres: 3107 (11.9%) were classified as B3, of which 1644 (54.2%) proceeded to SE to establish a definitive histological diagnosis of breast pathology. Due to a high proportion of microcalcifications as main radiological pattern, the overall PPV was 21.2% (range 10.6%–27.3% for different B3 subtypes), somewhat lower than the average value (24.5%) from published studies (range 9.9%–35.1%). Our study, to date the largest series of B3 with definitive histological assessment on SE, suggests that B3 lesions should be referred for SE even if VANCB is more accurate than NCB in the diagnostic process of non-palpable, sonographically invisible breast lesions

Alpha-Particle Monitoring Systems Based on a BJT Detector on High-Resistivity Silicon

A battery-powered, wireless alpha-ray sensor has been designed and realized using a high-resistivity-silicon BJT as radiation detector. Thanks to its excellent signal-to-noise ratio and intrinsic amplification, real-time alpha particle detection is possible using simple readout electronics which records alpha particle arrival time and charge spectrum

Numerical Simulation of Efficiency-Droop Mechanisms in InGaN/GaN Blue Light-Emitting Diodes

We will report on a systematic analysis of above aspects carried out by means of numerical device simulations. The aims of this analysis are (i) to improve understanding of droop mechanisms, (ii) to provide guidelines for LED optimization. Specific results will address 1) the suitability of pure droop mechanisms and/or the combination of 2 or more mechanisms to explain the droop, 2) the effects of above technological changes on IQE vs current curve

El abandono universitario: Qu\ue9 motiva a los estudiantes a dejar el Curso de Grado en Enfermer\ueda?

The attrition of nursing students, before the end of the course, is a problem for at least sixty years old, which covers all countries of the world. Many studies have been conducted on this topic, aimed to investigate the reasons for this phenomenon, however, the high dropout rates continue to be a cause for concern, because we are far from finding a solution to the problem. The purpose of this investigation was to analyze the phenomenon of within the two degree courses in Nursing, University of Modena and Reggio Emilia, with the aim to identify the following strategies to counteract the loss of future professionals. Methods: Structured telephone interviews were administered to students who have formally renounced studies between 01/01/2005 and 31/12/2009. The interviews were carried out during the period between July and October 2010 and were conducted according to a questionnaire consisting of 19 closed questions. Results: Out of a total of 94 students contacted, 59 telephone interviews were carried out (62.7%); 6 students (6.3%) refused the interview, while the remaining 31% has proved unreachable. The factors related to the motivation to leave the course, are divided into subjective factors and structural factors, and cover both the theoretical part of the course, the training in addition to environmental elements. Among the structural factors such as motivation of the withdrawal, the 28.8% of respondents claimed to have had learning problems in some aspects, while 23.8% said they had experienced difficulties in the clinical internship. Respondents then indicated as causes of attrition of the study, the disillusionment with the nursing profession (32.8%) and the lack of correspondence between what are the expectations and the reality that a student lives (14%)

Investigation of Efficiency-Droop Mechanisms in Multi-Quantum-Well InGaN/GaN Blue Light-Emitting Diodes

Efficiency-droop mechanisms and related technological remedies are critically analyzed in multi-quantum-well (QW) InGaN/GaN blue light-emitting diodes by means of numerical device simulations and their comparison with experimental data. Auger recombination, electron leakage, and incomplete QW carrier capture can separately produce droop effects in quantitative agreement with experimental data, but "extreme" values, at the limit of or outside their generally accepted range, must be imposed for related droop-controlling parameters. Less stringent conditions are needed if combinations of the aforementioned mechanisms are assumed to act jointly. Applying technological/structural modifications like QW thickness or number increase and barrier p-type doping leads to distinctive effects on droop characteristics depending on the assumed droop mechanism. Increasing the QW number appears, in particular, to be the most effective droop remedy in case the phenomenon is induced by Auger recombination. Possible technology-dependent variation of droop-controlling parameters and/or multiple droop mechanisms can, however, make discrimination of droop origin on the basis of the effects of applied technological remedies very difficult

Design and characterization of current-assisted photonic demodulators in 0.18-um CMOS technology

We report on the design of a Current-Assisted Photonic Demodulator (CAPD) using a standard 0.18-um CMOS technology, and its electro-optical characterization. The device can perform both light detection and demodulation in the charge domain, owing to a drift field generated in the silicon substrate by a majority carrier flow. Minimum-size, 10×10 um2 CAPDs exhibit a DC charge-transfer efficiency larger than 80% (corresponding to a demodulation contrast larger than 40% under sine-wave modulation) at the modest power consumption of 10 uW, and a 3-dB bandwidth > 45 MHz. An excellentlinearity with an error lower than 0.11% is obtained in phasemeasurements. CAPDs with optimized modulation-electrode geometries are finally designed, aiming at improved contrast-vs-power trade-off

Organic light-emitting transistors with voltage-tunable lit area and full channel illumination

Organic light-emitting transistors (OLETs) are multifunctional optoelectronic devices that hold great promise for a variety of applications, including flat panel displays, integrated light sources for sensing and optical communication systems. The narrow illumination area within the device channel is considered intrinsic to the device architecture and is a severe technological drawback for all those applications where a controlled, wide and homogeneous emission area is required. Here it is shown that not only the position but also the extension of the emission area is voltage-tunable, and the entire channel of the transistor can be homogeneously illuminated. The modeling of the exciton distribution within the channel at the different bias conditions coupled to the modeling of the device emission profile highlights that excitons are spread through the entire channel width and across the bulk of the central emission layer of the p-channel/emitter/n-channel trilayer active heterostructure