325 research outputs found
Multianalytical approach to characterize composition and degradation processes of synthetic high-fashion textiles from the Nanni Strada Design Studio archives
Synthetic textiles are constituents of heritage objects and garments often displayed in museum collections or preserved in archives, presenting unprecedented and specific conservation challenges. These issues need to be addressed assessing degradation processes, and developing targeted restoration and preventive conservation practices. The present work aims at characterizing the composition of high fashion garments and design textiles by Nanni Strada conserved in the archives of Nanni Strada Design Studio (Milan). To identify the chemical composition of the fibers used for the manufacturing, and to investigate the degradation processes affecting the objects, the materials were investigated by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Evolved Gas Analysis coupled to Mass Spectrometry (EGA-MS), and multi-shot Pyrolysis coupled to Gas Chromatography and Mass Spectrometry (Py-GC/MS). The results will contribute to a better knowledge of the chemical properties of the textiles produced in the 1970s, and to plan conservation and exhibition strategies
Titanium Nitride Coating of RF Ceramic Windows by Reactive DC Magnetron Sputtering
International audienceLAL-Orsay is developing an important effort on R&D and technology studies on RF power couplers for superconductive cavities. These are complex and high technology devices due to their basic functions: vacuum and temperature separation form the environment to the cavity. One of the most critical components of high power couplers is the ceramic RF window that allows the power flux to be injected in the coaxial line. The presence of a dielectric window on a high power RF line has in fact a strong influence on the multipactor phenomena, a resonant electron discharge that is strongly limiting for the RF components performances. The most important method to reduce the multipactor is to decrease the secondary emission yield of the ceramic window. Due to its low secondary electron emission coefficient, TiN thin film is used as a multipactor suppressor coating on RF ceramic coupler windows. In the framework of the EU program FP6 the LAL-Orsay and the LNL-Legnaro establish a collaboration to develop a coating bench that takes into account the different strong constraints on stoechiometry and film coating thickness given by coupler operating conditions. Reactive magnetron sputtering technology was chosen to obtain such deposit. A full description of a sputtering bench recently installed in LAL, and its main characteristics are given. Stoechiometric TiN films are obtained by optimization of reactive gas flow (N2), for a given bias and a given ionisation gas flow (Ar). XRD analysis was performed to control film composition. From the data obtained, lattice parameter is calculated for each deposit and film stoechiometry is determined. XPS analysis of stoechiometric film had shown the existence of oxygen and carbon mainly in the surface. However, it shows also that the ratio Ti/N in atomic percentage is equal to 1
Radioisotopic purity and imaging properties of cyclotron-produced 99mTc using direct 100Mo(p,2n) reaction
Evaluation of the radioisotopic purity of technetium-99m (99mTc) produced in GBq amounts by proton bombardment of enriched molibdenum-100 (100Mo) metallic targets at low proton energies (i.e. within 15\u201320 MeV) is conducted. This energy range was chosen since it is easily achievable by many conventional medical cyclotrons already available in the nuclear medicine departments of hospitals. The main motivation for such a study is in the framework of the research activities at the international level that have been conducted over the last few years to develop alternative production routes for the most widespread radioisotope used in medical imaging. The analysis of technetium isotopes and isomeric states (9xTc) present in the pertechnetate saline Na99mTcO4 solutions, obtained after the extraction/purification procedure, reveals radionuclidic purity levels basically in compliance with the limits recently issued by European Pharmacopoeia 9.3 (2018 Sodium pertechnetate (99mTc) injection 4801\u20133). Moreover, the impact of 9xTc contaminant nuclides on the final image quality is thoroughly evaluated, analyzing the emitted high-energy gamma rays and their influence on the image quality. The spatial resolution of images from cyclotron-produced 99mTc acquired with a mini-gamma camera was determined and compared with that obtained using technetium-99m solutions eluted from standard 99Mo/99mTc generators. The effect of the increased image background contribution due to Compton-scattered higher-energy gamma rays (E \u3b3 \u2009\u2009>\u2009\u2009200\u2009keV), which could cause image-contrast deterioration, was also studied. It is concluded that, due to the high radionuclidic purity of cyclotron-produced 99mTc using 100Mo(p,2n)99mTc reaction at a proton beam energy in the range 15.7\u201319.4 MeV, the resulting image properties are well comparable with those from the generator-eluted 99mTc
ABCD2, ABCD2-I, and OTTAWA scores for stroke risk assessment: a direct retrospective comparison
Transient ischemic attack (TIA) is a neurologic emergency characterized by cerebral ischemia eliciting a temporary focal neurological deficit. Many clinical prediction scores have been proposed to assess the risk of stroke after TIA; however, studies on their clinical validity and comparisons among them are scarce. The objective is to compare the accuracy of ABCD2, ABCD2-I, and OTTAWA scores in the prediction of a stroke at 7, 90 days, and 1 year in patients presenting with TIA. Single-centre, retrospective study including patients with TIA admitted to the Emergency Department of our third-level, University Hospital, between 2018 and 2019. Five hundred three patients were included. Thirty-nine (7.7%) had a stroke within 1 year from the TIA: 9 (1.7%) and 24 (4.7%) within 7 and 90 days, respectively. ABCD2, ABCD2-I, and OTTAWA scores were significantly higher in patients who developed a stroke. AUROCs ranged from 0.66 to 0.75, without statistically significant differences at each time-point. Considering the best cut-off of each score, only ABCD2 > 3 showed a sensitivity of 100% only in the prediction of stroke within 7 days. Among clinical items of each score, duration of symptoms, previous TIA, hemiparesis, speech disturbance, gait disturbance, previous cerebral ischemic lesions, and known carotid artery disease were independent predictors of stroke. Clinical scores have moderate prognostic accuracy for stroke after TIA. Considering the independent predictors for stroke, our study indicates the need to continue research and prompts the development of new tools on predictive scores for TIA
Psychological Treatment for Headache : A Pilot Study on the Efficacy of Joint Psychoeducational Group and Relaxation Training
Headache is a severe and disabling chronic condition. Literature shows that psycho-educational interventions may be useful for several chronic pain disorders. We tested an integrated psycho-educational and relaxation intervention addressed to patients suffering from headache.
The outcome indicators are a direct measure of headache (headache days per month) and two indirect measures (disability due to headache and medications used). At the end of the intervention patients also filled in a satisfaction questionnaire. Forty-seven subjects participated to the study. The treatment significantly reduced frequency of headache attacks (Wilcoxon p<0.01) and disability caused by headache (Wilcoxon p<0.001). There was also a sensible reduction in medication use. Almost all patients judged the intervention positively. An integrated approach may be very useful to ameliorate the burden of headache, to discontinue medication and to improve quality of lif
Características químicas de um latossolo sob diferentes sistemas de produção no noroeste paulista.
Sistemas de manejo conservacionistas que têm o intuito de evitar o desgaste ou a degradação do solo vêm sendo difundidos na agricultura. Este trabalho teve por objetivo avaliar as características químicas de um Latossolo sob sistema plantio direto, integração lavoura-pecuária e integração lavourapecuária- silvicultura, comparados a uma área de cerrado nativo, em Votuporanga, SP. Conclui-se que os sistemas de produção avaliados apresentaram, na fase inicial de implantação, características químicas desfavoráveis ao desenvolvimento das culturas, com baixos teores de fósforo e acidez elevada, semelhante a área de cerrado nativo, sendo necessário a continuidade dos estudos por um período maior
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