TRATTAMENTO DELLA PATOLOGIA APPENDICOLARE ACUTA OSSERVATA PRESSO IL PS-DEA DELL'AZIENDA OSPEDALIERO-UNIVERSITARIA DI CAREGGI: CASISTICA PERSONALE

Dopo una revisione della storia dell'appendicectomia fino allo stato attuale con gli sviluppi della tecnica laparoscopica, la tesi esamina dati epidemiologici, clinici con particolare riferimento agli interventi eseguiti ed alle complicanze precoci e tardive osservate in una casistica clinica composta da 120 pazienti

Flowmeter and Ground Penetrating Radar: comparison between hydrogeological and geophysical methods

We discuss a comparison between saturated hydraulic conductivity calculated with Electromagnetic Borehole Flowmeter (EBF) and water content obtained by Ground Penetrating Radar (GPR) Zero Offset Profile (ZOP

Direct X-ray photoconversion in flexible organic thin film devices operated below 1 v

The application of organic electronic materials for the detection of ionizing radiations is very appealing thanks to their mechanical flexibility, low-cost and simple processing in comparison to their inorganic counterpart. In this work we investigate the direct X-ray photoconversion process in organic thin film photoconductors. The devices are realized by drop casting solution-processed bis-(triisopropylsilylethynyl)pentacene (TIPS-pentacene) onto flexible plastic substrates patterned with metal electrodes; they exhibit a strong sensitivity to X-rays despite the low X-ray photon absorption typical of low-Z organic materials. We propose a model, based on the accumulation of photogenerated charges and photoconductive gain, able to describe the magnitude as well as the dynamics of the X-ray-induced photocurrent. This finding allows us to fabricate and test a flexible 2 × 2 pixelated X-ray detector operating at 0.2 V, with gain and sensitivity up to 4.7 × 10 4 and 77,000 nC mGy 1 cm 3, respectively

Protocol development for pro-active emergency responses by veterinary clinics and hospitals

The Gulf Coast hurricanes of 2005 necessitated the development of a guidance document concerning emergency preparedness and response for veterinary clinics and hospitals. The aftermaths of the largest natural disasters in United States\u27 history, namely Hurricanes Katrina and Rita, brought to light the need for a protocol designed specifically for veterinarians and veterinary practitioners. Disaster management information was synthesized and modified to be subject-specific for the veterinary community. This synthesis resulted in the creation of the Veterinary Emergency Preparedness and Response (VEPR) manual and website. Two types of data were collected to develop the emergency protocol; interviews with veterinarians and staff and site visits to affected clinics and hospitals were conducted to gather primary data for inclusion in the preparedness and response document, and preexisting information concerning disaster management from an array of sources was compiled and reviewed. A preliminary manual was provided to affected individuals for feedback and input and the subsequent comments were formatted and incorporated into a final protocol recommendation. Two deliverables resulted from the current study including a hardcopy VEPR manual and website based on the information from the manual, http://info.envs.lsu.edu/vepr/. The guidance document provides pertinent information for pre-hurricane planning, weathering the physical storm, and post-hurricane recovery. Together the manual and website facilitate the widespread distribution of the emergency recommendations to the veterinary community and are expected to be a comprehensive source for specific disaster management materials. The VEPR manual and website are resources that can be used as tools to mitigate damaging affects, particularly to lessen the post-disaster burden on the staff and operations of veterinary clinics and hospitals. VEPR provides a foundation for the development of viable emergency preparedness and response protocols for other types of natural disasters. Updates of VEPR will be needed so as to assure that the recommended protocol continues to be timely for national and global applications

Fully Textile X-Ray Detectors Based on Fabric-Embedded Perovskite Crystals

The interest and thrust for wearable ionizing radiation dosimeters are rapidly growing, stimulated by a large number of different applications impacting on humankind, spanning from medicine to civil security and space missions. Lead halide perovskites are considered one of the most promising classes of novel materials for X-ray detectors due to their superior electronic and detection performance coupled with compatibility with solution-based printing processes, allowing fabrication onto flexible substrates. It is reported on fully textile perovskite-based direct X-ray detectors, where the photoactive layer is constituted by a silk-satin fabric functionalized with methylammonium lead bromide perovskite crystals embedded in the textile. The reliability of the proposed fabrication process, based on simple and low-tech deposition techniques adaptable to industrial printing technologies for textiles, is assessed by realizing different detector's architectures that exhibit comparable detection performances. Sensitivity values up to (12.2 +/- 0.6) mu C Gy(-1) cm(-2) and a limit of detection down to 3 mu Gy s(-1) are achieved, and low bias operation (down to 1 V) is demonstrated, validating wearable applications. Further, fully textile pixelated matrix X-ray sensors are implemented and tested, providing the proof of principle for large-area scalability

Ultra-Stable and Robust Response to X-Rays in 2D Layered Perovskite Micro-Crystalline Films Directly Deposited on Flexible Substrate

2D layered hybrid perovskites have recently attracted an increasing interest as active layers in LEDs and UV–Vis photodetectors. 2D perovskites crystallize in a natural self-assembled quantum well-like structure and possess several interesting features among which low-temperature (<100 °C) synthesis and low defect density. Here are presented solid-state ionizing radiation direct detectors based on the 2D layered hybrid perovskite PEA2PbBr4 (PEA = C6H5C2H4NH3+) deposited from solution using scalable techniques and directly integrated onto a pre-patterned flexible substrate in the form of micro-crystalline films displaying crystal-like behavior, as evidenced by the ultra-fast (sub-microsecond) and good detection performances under UV light. The effective detection of X-rays (up to 150 kVp) is demonstrated with sensitivity values up to 806 µC Gy−1 cm−2 and Limit of Detection of 42 nGy s−1, thus combining the excellent performance for two relevant figures of merit for solid-state detectors. Additionally, the tested devices exhibit exceptionally stable response under constant irradiation and bias, assessing the material robustness and the intimate electrical contact with the electrodes. PEA2PbBr4 micro-crystalline films directly grown on flexible pre-patterned substrate open the way for large-area solid-state detectors working at low radiation flux for ultra-fast X-ray imaging and dosimetry

Direct X-ray photoconversion in flexible organic thin film devices operated below 1 v

The application of organic electronic materials for the detection of ionizing radiations is very appealing thanks to their mechanical flexibility, low-cost and simple processing in comparison to their inorganic counterpart. In this work we investigate the direct X-ray photoconversion process in organic thin film photoconductors. The devices are realized by drop casting solution-processed bis-(triisopropylsilylethynyl)pentacene (TIPS-pentacene) onto flexible plastic substrates patterned with metal electrodes; they exhibit a strong sensitivity to X-rays despite the low X-ray photon absorption typical of low-Z organic materials. We propose a model, based on the accumulation of photogenerated charges and photoconductive gain, able to describe the magnitude as well as the dynamics of the X-ray-induced photocurrent. This finding allows us to fabricate and test a flexible 2 × 2 pixelated X-ray detector operating at 0.2 V, with gain and sensitivity up to 4.7 × 10^4 and 77,000 nC mGy ^(-1) cm^(-3), respectively

Non-Destructive Techniques in the Consolidation Works of the Church of S.M. of Itria in Piazza Armerina (Italy)

A real case of consolidation works is presented in which only field testing methods can reveal the causes of instability. This paper is an update of the one presented at the SAHC 2018 conference, concerning the study of the partial collapse of the Church of Itria in Piazza Armerina (Sicily, Italy). The previous paper beared hypotheses and design solutions based only on indirect investigations, theoretical formulations and checks with software. The consolidation works, started in November 2018 and still in progress, have made it possible to formulate new and documented hypotheses on the collapse and to integrate and partly modify the solutions hypothesized previously. In particular, the reconstruction techniques of the wall and chains have been confirmed. The new interventions have, instead, concerned the consolidation of the foundation soil which was found to be insubstantial,following electrical tomographic investigations, due to the presence of voids. At the same time, inspections were carried out on an old masonry sewage pipe which revealed several points of discontinuity through which large quantities of water entered under the walls of the church causing the removal of inconsistent elements from the ground. At first, the reconstruction of the collapsed wall was done and the restoration of the existing wall structures, to eliminate the causes of the collapse through the intervention on the sewage pipe and filling the voids under the foundations. The most important intervention, which required the use of innovative materials, forefront equipment and skilled labor, involved the filling the voids under the foundations through perforations every 50 cm, both on the inner and outer wire of the collapsed wall. Clamped canes were set in order to intercept the voids highlighted by the tomography. A 100% expansive mortar was injected at low pressure through the canes, filling one cane at a time and progressively raising the point of exit of the mortar until the higher far end. After this consolidation, the foundation and the wall were rebuilt with local limestone ashlars to have fair faced aspect as the original masonry. At the end of the work, further tomographic tests are planned to verify the validity of the interventions carried out

Trap States Ruling Photoconductive Gain in Tissue-Equivalent, Printed Organic X-Ray Detectors

Organic semiconductors are excellent candidates for X-ray detectors that can adapt to new applications, with unique properties including mechanical flexibility and the ability to cover large surfaces. Their chemical composition, primarily carbon and hydrogen, makes them human tissue equivalent in terms of radiation absorption. This is a highly desirable property for a radiation dosimeter to be employed in medical diagnostics and therapy, however a low-Z composition limits the absorption of ionizing radiation. The detection efficiency can be enhanced by considering the photoconductive gain (PG) effect, a significant contributor to the ionizing radiation detection mechanism in this class of materials. In this work, a process of controlled solution deposition by nozzle printing and crystallization of an organic semiconductor thin film is demonstrated whereby a flexible, arrayed thin-film X-ray detector with record X-ray sensitivities among flexible radiation detectors (S = (9.0 +/- 0.4) x 10(7) mu C Gy(-1) cm(-3)) is developed. The excitonic peaks responsible for the activation of the PG effect are investigated and identified using a novel technique called photocurrent spectroscopy optical quenching, and the analysis of the changes in trap states is further demonstrated

Morphology and mobility as tools to control and unprecedentedly enhance X-ray sensitivity in organic thin-films

Organic semiconductor materials exhibit a great potential for the realization of large-area solution-processed devices able to directly detect high-energy radiation. However, only few works investigated on the mechanism of ionizing radiation detection in this class of materials, so far. In this work we investigate the physical processes behind X-ray photoconversion employing bis-(triisopropylsilylethynyl)-pentacene thin-films deposited by bar-assisted meniscus shearing. The thin film coating speed and the use of bis-(triisopropylsilylethynyl)-pentacene:polystyrene blends are explored as tools to control and enhance the detection capability of the devices, by tuning the thin-film morphology and the carrier mobility. The so-obtained detectors reach a record sensitivity of 1.3 \ub7 104 \ub5C/Gy\ub7cm2, the highest value reported for organic-based direct X-ray detectors and a very low minimum detectable dose rate of 35 \ub5Gy/s. Thus, the employment of organic large-area direct detectors for X-ray radiation in real-life applications can be foreseen