28 research outputs found

    Dialkyl carbonates: scale-up synthesis and application as green solvents for PVDF membranes preparation

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    Dialkyl carbonates (DACs) are well-known green solvents and reagents that have been extensively investigated as safe alternatives to chlorine-based compounds. In fact, they can replace alkyl halides and dimethyl sulfate in alkylation and carbonylation reactions as well as phosgene and its derivatives in alkoxycarbonylation ones. Recently we have developed a high yielding scale-up synthesis of non-commercially available or expensive DACs via transcarbonylation reactions of an alcohol with dimethyl carbonate (DMC) promoted by the nitrogen-based organocatalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene TBD. Compared to previously published works, the proposed procedure has been customized for DACs large scale production (up to 100 mL of product obtained). Purification of these compounds has been achieved by fractional distillation and the exceeding reagents have been recovered and recycled. Selected DACs for this study include both symmetrical and unsymmetrical compounds, incorporating several alkyl, alkoxyalkyl, alkylamino and alkylthio functional groups. Chemical-physical properties of the new DACs have been also evaluated, as well as their water solubility. Furthermore, biodegradability and cytotoxicity tests have been carried out to investigate the effects of the different substituents on the greenness of these potential solvents and reagents. DACs application as green solvents for membrane preparation was next investigated, using non-solvent induced phase separation (NIPS) and vapor induced phase separation (VIPS) techniques, achieving both porous and plain membranes [4]. Morphology, additives effect, physical-chemical and mechanical proprieties as well as their performances in terms of water permeability and rejection were evaluated and compared to membranes obtained using commercially available cyclic carbonates (namely ethylene carbonate – EC and propylene carbonate – PC)

    Local environment of Barium, Cerium and Yttrium in BaCe1-xYxO3-d ceramic protonic conductors

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    Y-doped barium cerate protonic conductors with composition BaCe1 − xYxO3 − δ (x=0.02, 0.1, 0.2, 0.3) have been synthesized by sol–gel route, giving by X-ray diffraction tests a homogeneous crystalline phase. A commercial sample BaCe0.8Y0.2O3 − δ produced by combustion spray pyrolysis was also provided for comparison aim. The local structure around the cations was studied by X-ray absorption spectroscopy at the K-edges of Ba, Ce and Y. It is demonstrated that the insertion of yttrium in the site of cerium produces a remarkable local distortion of the dopant first-shell octahedral environment that affects also the next coordination shells by a static disorder increasing with dopant amount. For a dopant concentration estimated as x N 0.17, a poorly crystallized yttrium oxide phase that cannot be detected by X-ray diffraction is segregated. The static disorder around Y noticeably increases in the protonated samples and can be related to a preferential location of protons near the dopant

    Female sex and the risk of liver cirrhosis

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    Background: Evidence on gender-related differences in susceptibility to alcohol-induced liver diseases is questionable with regard to both methodologic and clinical aspects. With the aim to assess the role of gender in the risk of liver cirrhosis, independently and in combination with known risk factors, data from three case-control studies performed in various Italian areas were analysed. Methods: The cases were 462 cirrhotic patients (300 men and 162 women) admitted for the first time to hospital for liver decompensation. Controls were 651 patients (355 men and 296 women) admitted to the same hospitals during the same period as the cases, for acute diseases unrelated to alcohol. Alcohol consumption was expressed as lifetime daily alcohol intake. Results: A significant and independent associations between alcohol intake, chronic hepatitis B and C virus infections, and the risk of liver cirrhosis was observed. The effect of alcohol intake was multiplicatively increased in women. The odds ratio (OR) increased from 1.0 (reference category: men, lifetime abstainers) to 31.4 (95% confidence interval (CI), 10.3-95.8) in men drinking more than 100 g/day of alcohol, and from 2.2 (95% CI, 1.0-7.1) in abstaining women to 44.8 (95% CI, 8.2-224.0) in women drinking more than 100 g/day of alcohol. An increased risk of liver cirrhosis associated with female gender independently of alcohol consumption and virus infection was also observed. Conclusions: A higher susceptibility to alcohol-induced liver diseases was confirmed for women, and an independent effect of female sex on the risk of cirrhosis was observed. Besides alcohol and viruses, some unknown gender-related factor might then be involved in the occurrence of the disease

    Book of Abstracts ITM SEMINAR DAY 2021

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    Dialkyl carbonates (DACs) are well-known green solvents and reagents that are extensively investigated as safe alternatives to chlorine reagents. In fact, they can replace alkyl halides and dimethyl sulfate in alkylation and carbonylation reactions as well as phosgene and its derivatives in the alkoxycarbonylation ones [1,2]. In this talk, I will be presenting our latest results in the high yielding scale-up synthesis of non-commercially available or expensive DACs via transcarbonylation reactions of an alcohol with DMC promoted by the nitrogen-based organocatalyst, 1,5,7- triazabicyclo[4.4.0]dec-5-ene (TBD). Compared to previously published works [3,4], the proposed procedure has been customized for DACs large scale production (up to 100 mL of product obtained). Purification of these compounds has been achieved by fractional distillation and the exceeding reagents have been recovered and recycled. The selected DACs for this study include both symmetrical and unsymmetrical compounds, incorporating several alkyl, alkoxyalkyl, alkylamino and alkylthio functional groups. Chemical-physical properties of the new DACs have been also evaluated, as well as their water solubility. Furthermore, biodegradability and cytotoxicity tests have been carried out to investigate the effects of the different substituents on the greenness of these potential solvents and reagents. Finally, both commercially available cyclic carbonates (namely ethylene carbonate – EC and propylene carbonate – PC) and selected samples of the newly synthetized DACs, have been investigated as green solvents for membrane preparation, using nonsolvent induced phase separation (NIPS) and vapor induced inverse phase separation (VIPS) techniques, achieving both porous and plain membranes. Physical-chemical, morphology, mechanical proprieties and the performance in terms of water permeability and rejection of these new membranes have been also evaluated

    Is alcohol a risk factor for liver cirrhosis in HBsAg and anti-HCV negative subjects?

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    Abstract: Background/Aims: in order to evaluate the association between alcohol intake and the risk of liver cirrhosis in the absence of B and C hepatitis viruses, we analyzed data from three hospital-based case-control studies performed in various Italian areas. Methods: From the case and control series we excluded HBsAg and/or anti-HCV positive patients. eases were 221 cirrhotic patients admitted for the first time to hospital for liver decompensation. Controls were 614 patients admitted to the same hospitals during the same period as the cases for acute diseases unrelated to alcohol. Alcohol consumption was expressed as lifetime daily alcohol intake (LDAI). Results: We found a dose-effect relationship between LDAI and the risk of liver cirrhosis (LC). Considering the extreme LDAI categories (LDAI=0 g: lifetime teetotallers and LDAI greater than or equal to 100 g), the EC odds ratio (OR) increased from 1.0 (reference category) to 44.7 (95% confidence interval: 95% CI: 20.0-99.9). An increased risk of LC associated with the female gender independent of alcohol consumption was also observed (OR=2.9; 95% CI: 1.8-4.6). Conclusions: Alcohol intake acts as a risk factor for symptomatic liver cirrhosis also in the absence of HBV and/or MCV infection. Besides alcohol and viruses, some unknown gender-related factors might he involved in the occurrence of the diseas

    Interaction between dietary pattern and alcohol intake on the risk of liver cirrhosis. The Provincial Group for the Study of Chronic Liver Disease.

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    In order to assess the inter-relationship between nutritional intake and alcohol consumption on the risk of liver cirrhosis we performed a hospital-based retrospective case-control study. We enrolled 115 cases admitted to hospital for liver decompensation at their first diagnosis of liver cirrhosis and 167 hospital controls without evidence of liver disease admitted for acute diseases unrelated to alcohol intake. Daily alcohol intake and average nutrient intake were measured throughout the patient's life, using a reproducible questionnaire. No dose-effect relationship was found between nutrient intake and risk of cirrhosis using classical association statistical methods. We then corrected the intake of each nutrient for the total caloric intake and this energy-adjusted nutrient intake was used in a logistic regression model together with alcohol intake, viral B and C hepatitis markers, age and gender. Using this approach, carbohydrates intake were shown to have a protective effect on the risk of cirrhosis, whereas saturated lipid intake had a significant multiplicative effect on the risk associated with alcohol consumption. By comparison with the teetotalers category who had an average daily intake of saturated fatty acids lower than 40.3 g (reference category; OR = 1), drinkers of more than 100 g ethanol per day showed ORs ranging from 14.2 (95% confidence interval 2.0-101.0) for consumers of less than 40.3 g fatty acid per day, to 39.0 (95% confidence interval 5.0-305.1) for consumers of more than 40.4 g fatty acid per day. In conclusion we give additional evidence on the relationship between diet and risk of cirrhosis, whereby saturated lipid intake multiplies the risk associated with alcohol intake. However, caution should be used to interpret such results, since they seem to suggest that diet but not a particular nutrient can modify the effect of alcohol on the risk of cirrhosis. The present lack of agreement on the mechanisms and the nutrients involved in the pathogenesis of alcoholic liver injury should stimulate wider epidemiological studies using modern nutritional techniques

    EEG-based brain-computer interface to support post-stroke motor rehabilitation of the upper limb

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    Brain-Computer Interfaces (BCIs) process brain activity in real time, and mediate non-muscular interaction between and individual and the environment. The subserving algorithms can be used to provide a quantitative measurement of physiological or pathological cognitive processes - such as Motor Imagery (MI) - and feed it back the user
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