483 research outputs found
Recommendation for future actions in research and developments
The Sustainable Chemistry Issue Team has been active within the OECD Environment Health and Safety Programme since 1998 and has held many meetings in Germany and in Italy.
Although Italy has organized two meetings (Venice, 1998 and 2001) and has an excellent scientific and technological background in the field, the coordination among research, academy and industry, necessary to undertake actions among the
leader countries of this area, has not yet been activated. At this end the University Ca’ Foscari of Venice, in collaboration with the Istituto Superiore di Sanità (ISS – Italian Institute for Health) that co-ordinates in Italy the OECD activities in the framework of
the Environment, Health and Safety Programme, has organized this Workshop aimed to the establishment of the Italian network on green and sustainable chemistry.
The connection with EU achievements and with the recently instituted OECD Green Growth Knowledge Platform has been highlighted.
The first part of the Workshop has addressed European activities carried out in this field. OECD, EuCheMS, UNESCO have participated. The second part, organised in collaboration with pertinent Italian ministries, universities, public research institutes and industries has highlighted the different point of views inherent to the sustainable development and in particular the state of art of the green and sustainable chemistry in Italy in connection with its international perspectives
Neurophysiological vigilance characterisation and assessment: Laboratory and realistic validations involving professional air traffic controllers
Vigilance degradation usually causes significant performance decrement. It is also considered the major factor causing the out-of-the-loop phenomenon (OOTL) occurrence. OOTL is strongly related to a high level of automation in operative contexts such as the Air Traffic Management (ATM), and it could lead to a negative impact on the Air Traffic Controllers’ (ATCOs) engagement. As a consequence, being able to monitor the ATCOs’ vigilance would be very important to prevent risky situations. In this context, the present study aimed to characterise and assess the vigilance level by using electroencephalographic (EEG) measures. The first study, involving 13 participants in laboratory settings allowed to find out the neurophysiological features mostly related to vigilance decrements. Those results were also confirmed under realistic ATM settings recruiting 10 professional ATCOs. The results demonstrated that (i) there was a significant performance decrement related to vigilance reduction; (ii) there were no substantial differences between the identified neurophysiological features in controlled and ecological settings, and the EEG-channel configuration defined in laboratory was able to discriminate and classify vigilance changes in ATCOs’ vigilance with high accuracy (up to 84%); (iii) the derived two EEG-channel configuration was able to assess vigilance variations reporting only slight accuracy reduction
Natural cytotoxicity impairment in familial haemophagocytic lymphohistiocytosis.
Ten children with the characteristic clinical and haematological features of haemophagocytic lymphohistiocytosis are reported. Four patients treated with a combination of drugs comprising etoposide, methotrexate, and steroids were in complete remission after 10 to 30 months. Natural cytotoxic mechanisms including natural killer cell activity, antibody dependent cell mediated cytotoxicity, lymphokine activated killer cell activity, and natural killer cell like activity were persistently absent or severely impaired in these four patients despite their clinical remission. Their parents and one healthy sibling also had impaired natural cytotoxic mechanisms. Constitutional impairment of natural cytotoxic mechanisms could be important in the pathogenesis of haemophagocytic lymphohistiocytosis
Recognition of Intentional Violations of Active Constraints in Cooperative Manipulation Tasks
Active Constraints (ACs) are high-level control algorithms deployed to assist a human operator in man-machine cooperative tasks [1], and define regions within which it is safe for the robot to move and cut [2]. To enhance the performance in cooperative surgical tasks,
adaptive constraints have been exploited to optimally adjust the provided level of assistance according to some knowledge of the task, hardware or user. In [3] Hidden Markov Models were used for the run-time detection of the user intention to leave a guidance
constraint to circumvent an obstacle. In this work, we present a novel, Neural Network (NN)-based method for the runtime classification of intentional and unintentional violations of ACs, that is trained on either statistical or frequency features from the enforced
constraint forces. We investigate which set of parameters yield faster and more reliable classification results, both for guidance and regional constraints
Methylation of 2-Naphthol Using Dimethyl Carbonate under Continuous-Flow Gas-Phase Conditions
Durability of a recombination catalyst-based membrane-electrode assembly for electrolysis operation at high current density
Hydrogen production through polymer electrolyte membrane water electrolysis was investigated at high current density (4 A cm-2). A PtCo recombination catalyst-based membrane-electrode assembly (MEA) was assessed in terms of performance, efficiency and durability. The electrolysis cell consisted of a thin (50 µm) perfluorosulfonic acid membrane and low platinum group metals (PGM) catalyst loadings (0.6 mgMEA PGM cm-2). An unsupported PtCo catalyst was successfully integrated in the anode. A composite catalytic layer made of IrRuOx and PtCo assisted both oxygen evolution and oxidation of hydrogen permeated through the membrane. The cell voltage for the recombination catalyst-based MEA was about 30 mV lower than the bare MEA during a 3500 h durability test. The modified MEA showed low performance losses during 3500 hours operation at high current density (4 A cm-2) with low catalyst loadings. A decay rate of 9 µV/h was observed in the last 1000 hours. These results are promising for decreasing the capital costs of polymer electrolyte membrane electrolysers. Moreover, the stable voltage efficiency of about 80% vs. the high heating value (HHV) of hydrogen at 4 A cm-2, here achieved, appears very promising to decrease operating expenditures
Multiphase oxidation of alcohols and sulfides with hydrogen peroxide catalyzedby heteropolyacids
This work describes the application of a multiphase system for the oxidation of alcohols to ketones or
aldehydes, and the selective conversion of sulfides to sulfoxides or sulfones using Keggin-type
heteropolyacids and hydrogen peroxide. Benzylic and secondary alcohols were oxidized to ketones or
aldehydes at 70 °C in good yield and selectivity. Similarly, sulfides were converted to sulfoxides or sulfones at
room temperature with high yields and selectivity
Reaction of dialkyl carbonates with alcohols:Defining a scale of the best leaving and entering groups
A series of dialkyl and methyl alkyl carbonates has been synthesized and their reactivity investigated. The behavior of preferential leaving and entering groups for the newly synthesized carbonates has been accurately investigated. Both experimental and computational studies agreed that the scale of leaving groups follows the trend: PhCH2O–, MeO– ≥ EtO–, CH3(CH2)2O–, CH3(CH2)7O– > (CH3)2CHO– > (CH3)3CO–. Accordingly, the scale of the entering group has the same trend, with t-butoxide being the worst entering group. A preliminary attempt to rationalize the nucleofugality trends, limited to the (CH3)3CO– and CH3O– groups, has indicated that a likely origin of the observed trends lies in the different entropic contributions and solvation effects
NarE: a novel ADP-ribosyltransferase from Neisseria meningitidis.
Mono ADP-ribosyltransferases (ADPRTs) are a class of functionally conserved enzymes present in prokaryotic and eukaryotic organisms. In bacteria, these enzymes often act as potent toxins and play an important role in pathogenesis. Here we report a profile-based computational approach that, assisted by secondary structure predictions, has allowed the identification of a previously undiscovered ADP-ribosyltransferase in Neisseria meningitidis (NarE). NarE shows structural homologies with E. coli heat-labile enterotoxin (LT) and cholera toxin (CT) and possesses ADP-ribosylating and NAD-glycohydrolase activities. As in the case of LT and CT, NarE catalyses the transfer of the ADP-ribose moiety to arginine residues. Despite the absence of a signal peptide, the protein is efficiently exported into the periplasm of Neisseria. The narE gene is present in 25 out of 43 strains analysed, is always present in ET-5 and Lineage 3 but absent in ET-37 and Cluster A4 hypervirulent lineages. When present, the gene is 100% conserved in sequence and is inserted upstream of and co-transcribed with the lipoamide dehydrogenase E3 gene. Possible roles in the pathogenesis of N. meningitidis are discussed
- …