27 research outputs found

    Titanium and Ruthenium Phthalocyanines for NO2 Sensors: A Mini-Review

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    This review presents studies devoted to the description and comprehension of phenomena connected with the sensing behaviour towards NO2 of films of two phthalocyanines, titanium bis-phthalocyanine and ruthenium phthalocyanine. Spectroscopic, conductometric, and morphological features recorded during exposure to the gas are explained and the mechanisms of gas-molecule interaction are also elucidated. The review also shows how X-ray reflectivity can be a useful tool for monitoring morphological parameters such as thickness and roughness that are demonstrated to be sensitive variables for monitoring the exposure of thin films of sensor materials to NO2 gas

    Remote Laboratory System: A Model Proposal and Implementation on X-Ray Laboratory Machines

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    This work presents the development and implementation of a remote X-ray laboratory, located at CNR – ISM, Rome, Italy. The remote laboratory model is based on a innovative, flexible and scalable modular architecture which makes it easier to update, expand or deal with problems. The developed system, accessible for control only to authenticated users, provides a remote control of the laboratory equipment, a real time visual feedback of the machinery and the opportunity to retrieve and make a preliminary analysis of stored data. These features offer the possibility to researchers of carrying out real research experiments remotely, avoid the exposure to ionizing radiation produced by the X-Ray equipment. The system also provides the opportunity of carrying out experiments programmatically, optimizing the use of available machine time and providing the possibility of running experiments in special environment-dependent conditions. Eventually, the system allows researchers located outside of laboratory site to run experiments in a collaborative way

    Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

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    IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

    Applicazione della diffrazione a dispersione di energia allo studio della cinetica di transizione di fase in campioni polimerici

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    Dottorato di ricerca in scienza dei materiali. 8. ciclo. A.a. 1994-95. Coordinatore A. Frova. Relatore R. CaminitiConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

    Angular calibration in energy dispersive X-Ray diffraction by using genetic algorithms

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    In Energy Dispersive X-Ray diffraction measurements, the estimate of momentum transfer q, on which the diffracted intensity depends, should be as accurate as possible. Since q, in turn, depends on both the energy and the scattering angle, an error on the latter due to an incorrect positioning of the sample, to the asymmetric angular spread induced by the collimation slits or, in general, to any uncertainty on the geometric setup, results in an uncertainty on the q value. Here, a new self calibration method to correct such errors, based on a genetic algorithm is presented. It is robust, fast and completely automatic. Results obtained by carrying out Energy Dispersive X-Ray Diffraction measurements on reference samples are reported and discussed. They show how the application of such genetic algorithm may provide a fast esteem of the two parameters required when multiple angle pattern collection is performed, namely the effective starting angle and the angular step. In this way, reliable q-values of all the diffraction pattern features (Bragg peaks for crystalline, and diffused bumps for non-crystalline samples) are obtained

    First measurements by the EDXD-PT technique of the effect of the melting time on polymer crystallisation kinetics

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    A nonconventional energy-dispersive X-ray diffraction method applied to phase transitions (EDXD-PT) was used to measure polymer crystallization rates. It enables one to follow the kinetics of phase transitions by a direct comparison of diffraction patterns collected during the process and suitably normalized with respect to X-ray absorption spectra taken with the same time scan. With this technique, the memory that a polymer retains of its thermal history is investigated by correlating the crystallization rates to the residence time in the melt

    Effect of disturbance induced by the electronic noise on the Energy Dispersive X-ray Diffraction patterns collection

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    The Energy Dispersive X-ray Diffraction (EDXD) proved to be an interesting alternative to its conventional Angular Dispersive counterpart (ADXD) each time the in situ measurements are of concern. Indeed, although its resolution is lower than that of ADXD, nevertheless it may allow a very accurate determination of even minimal changes of crystalline powders lattice parameters, thanks to several advantages it exhibits with respect to ADXD. Among these advantages, discussed in the paper, the main is that no motion is required upon diffraction pattern collection. However, the reliability of EDXD results may be compromised by the presence of an electronic noise that, along with a broadening of the Bragg peaks, may induce a shift of their positions. To evaluate the magnitude of such shift and, therefore, the level of confidence in determining the lattice parameters, a systematic study of the disturbance due to the electronic noise is reported
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