Sulla misura delle tensioni residue con il metodo del foro: metodi di calcolo per le tecniche sperimentali a campo intero

The hole drilling technique is a well known experimental method for residual stress investigation. This technique is usually used in combination with electrical strain gages but there is no reason to enforce this choice and other approach are possible. In particular some optical measurement techniques (grating interferometry, speckle interferometry, holographic interferometry, shearography) can be advantageously used. Since all these optical techniques give a full field information, it becomes important to properly use their data to increase the robustness and reliability of the analysis. In this work, various well known approaches to this problem will be investigated using a known displacement field as a reference. In this way it will be possible to discover the best performing algorithm in terms of robustness and reliability

Un nuovo algoritmo di Phase Unwrapping basato sulla crescita competitiva di regioni

The phase unwrapping problem arises every time one has to analyse experimental data acquired by means of techniques based on periodical phenomena, from the opto-interferometric ones to some geologycal or medical techniques. This paper presents a new phase unwrapping algorithm based on the competitive region growing: starting from an equipotential condition, it makes an area to absorb its neighbours by mean of a quality parameter based on the extension and the coherency of the regions. After a short description of the phase unwrapping problem and of some of the most used techniques, this paper describes the working principle of the algorithm and the implementation details. The paper ends with some examples of applications of the algorithm on synthetic images

Sviluppo di un sensore interferometrico per il controllo del posizionamento di un rugosimetro ottico

The optical profilometer that is under development at the Mechanical Engineering Department of the University of Cagliari (DiMeCa) requires a translation stage able to displace part of the optical system with sub-micrometric resolution. This work describes the development of an interferometric displacement sensor which enables, by its feedback, to accurately control an otherwise open loop controlled electrostrictive translation stage. After a short description of the optical system, the mechanical assembly, the electronic module and the software interface will be described. At the end some experimental result, showing the performances of the sensor will be illustrated

Sulla interferometria olografica digitale

The holographic interferometry is a well-known experimental technique which allows for measuring the displacements field of a sample in a relatively simple way. In its classical implementation, this technique uses high sensitivity photographic plates as recording media; nevertheless there is no reason why a different recording support, for example a CCD camera, can not be used (obviously in this case the reconstruction step has to be performed in numerical form). Since most of the industries producing holographic plates have stopped their lines, the digital version of holographic interferometry is becoming more than an option: this work aims to establish the limitation and the technical aspects that have to be taken into account when using a camera as the recording media. In fact, the low spatial resolution of the hardware requires special precaution to be taken both while building the setup and while performing the measurement

Sull'uso del phase shifting spaziale nella ricostruzione di campi di spostamento con tecniche ottiche

The Spatial Phase Shifting technique makes possible to reconstruct the displacement field using the Fourier analysis of a single image. However, in its “classical” version it presents various problems—first of all the residual component of the carrier fringe field—which seriously limits its usability. This work proposes to combine some techniques, either well known, either new, with the classical spatial phase shifting algorithm so as to enlarge its working field. After illustrating these techniques and their synergic effect, a series of test problems are analyzed showing the reliability of the proposed methodology

Cytological and histological diagnosis of lung cancer in Sardinia and Italy in the 1990s

Background. Up to 30-50% of all lung cancer cases remain without cyto-histological characterisation. The aim of our study was to evaluate retrospectively the proportion of histological and/or cytological diagnosis in patients with lung cancer in Sardinia. Methods. Data was gathered by consulting the hospital registers and case notes of individual patients released from hospital with a diagnosis of Lung Cancer at all medical centres throughout Sardinia. In gathering patients' data, we focused our attention on cytological and histological procedures through which allowed the lung cancer was diagnosed. Cancer Registries data was utilised to compare our data with national and Sassari province data. Results. From 1991 to 1996 there was a total of 3146 lung cancer patients registered in Sardinia. 1902 patients (60.5%) had a histological diagnosis, 142 patients (4.5%) a cytological diagnosis while in 1102 patients (35%) the diagnosis was performed without any pathological validation. Conclusions. Our study has shown that lung cancer diagnosis is supported by pathological verification in 65% of cases while in remaining 35% of patients the diagnosis is based only on clinical and radiological reports. In Italy data from Cancer Registries report the percentage of cyto- histological diagnosis to be 70% with the percentage of cytological diagnosis being higher than in Sardinia

Deciduoid mesothelioma of the thorax: A comprehensive review of the scientific literature.

AbstractObjectiveDeciduoid mesothelioma is a rare variant of malignant epithelioid mesothelioma. It often involves the peritoneum, but also thoracic cases have been reported. The aim of the present review is to describe the demographic, clinical, radiological, and pathological features of such a rare variant of thoracic mesothelioma, and the state of the art regarding the therapeutic approaches currently available.Data sourceEnglish‐language articles published from 1985 to June 2016, and related to thoracic deciduoid mesothelioma cases were retrieved using the Pubmed database.Study selectionThe search terms were "mesothelioma," "thoracic mesothelioma," "epithelial mesothelioma," "pleural mesothelioma," and "deciduoid mesothelioma."ResultsForty‐four cases included in 16 articles, published in the period under investigation, were analyzed in detail.ConclusionsThe mean age of the patients was 63 years, and the male to female ratio 1.7:1. Approximately 58% had exposure to asbestos, and 73% had a smoking history; familiarity was rarely reported. The most common anatomical site of origin was the right pleura, and the most frequent clinical manifestations were chest pain, dyspnea, cough, and weight loss. Thoracic X‐ray and computed tomography were the imaging techniques most employed for diagnosis and surgical planning. The pathological diagnosis was obtained by examination of surgical or biopsy specimens in most cases. The best treatment strategy of deciduoid mesothelioma is a matter of debate; nevertheless a multidisciplinary approach is currently the best option for the choice of the adequate therapeutic scheme

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks