868 research outputs found
Brainâcomputer interfaces: Toward a daily life employment
Recent publications in the Electroencephalogram (EEG)-based brainâcomputer interface field suggest that this technology could be ready to go outside the research labs and enter the market as a new consumer product. This assumption is supported by the recent advantages obtained in terms of front-end graphical user interfaces, back-end classification algorithms, and technology improvement in terms of wearable devices and dry EEG sensors. This editorial paper aims at mentioning these aspects, starting from the review paper âBrainâComputer Interface Spellers: A Reviewâ (Rezeika et al., 2018), published within the Brain Sciences journal, and citing other relevant review papers that discussed these points
Acid catalyzed synthesis of dimethyl isosorbide via dimethyl carbonate chemistry
Dimethyl isosorbide (DMI) is a bio-based solvent that can be used as green alternative for conventional dipolar
media (dimethyl sulfoxide, dimethylformamide, and dimethylacetamide). The main synthetic procedures to DMI
reported in the literature are based on the methylation of isosorbide employing different alkylating agents
including toxic halogen compounds such as alkyl halides. A more sustainable alternative would be to employ
dimethyl carbonate (DMC), a well-known green reagent and solvent, considered one of the most promising
methylating agents for its good biodegradability and low toxicity. Indeed, in recent years, DMC-promoted
methylation of isosorbide has been extensively exploited although mostly in the presence of a base or an
amphoteric catalyst. In this work, we report for the first time a comprehensive investigation on the synthesis of
DMI via DMC chemistry promoted by heterogeneous acid catalyst (Amberlyst-36 and Purolite CT275DR). Re-
action conditions were optimized and then applied for the methylation of isosorbide and its epimers, isoidide and
isomannide. Considerations on the related reaction mechanism were reported highlighting the difference in the
preferred reaction pathways among this new synthetic approach and the previously reported base-catalyzed
procedures
Lessons in learning gain: insights from a pilot project
âLearning gainâ has become an increasingly prominent concept in debates about the effectiveness of higher education across OECD countries. In England, interest has been heightened by the Higher Education Funding Council for England (HEFCE)âs major research initiative on learning gain, launched in 2015, and by the new Teaching Excellence Framework which assesses learning and teaching and student outcomes. HEFCEâs novel research initiative has funded a set of experimental projects across the English higher education sector for the first time. This paper presents preliminary findings from one such project at the University of East Anglia (UEA). The project trials and evaluates three approaches to identifying and measuring learning gain using data from cohorts of students across different discipline areas during 2015â2016 and 2016â2017. It builds upon previous work carried out at UEA in developing self-efficacy assessments and applying concept inventories. Student marks provide a simple comparator as a third approach to measuring learning gain
Joint analysis of eye blinks and brain activity to investigate attentional demand during a visual search task
In several fields, the need for a joint analysis of brain activity and eye activity to investigate the association between brain mechanisms and manifest behavior has been felt. In this work, two levels of attentional demand, elicited through a conjunction search task, have been modelled in terms of eye blinks, brain activity, and brain network features. Moreover, the association between endogenous neural mechanisms underlying attentional demand and eye blinks, without imposing a time-locked structure to the analysis, has been investigated. The analysis revealed statistically significant spatial and spectral modulations of the recorded brain activity according to the different levels of attentional demand, and a significant reduction in the number of eye blinks when a higher amount of attentional investment was required. Besides, the integration of information coming from high-density electroencephalography (EEG), brain source localization, and connectivity estimation allowed us to merge spectral and causal information between brain areas, characterizing a comprehensive model of neurophysiological processes behind attentional demand. The analysis of the association between eye and brain-related parameters revealed a statistically significant high correlation (R > 0.7) of eye blink rate with anterofrontal brain activity at 8 Hz, centroparietal brain activity at 12 Hz, and a significant moderate correlation with the participation of right Intra Parietal Sulcus in alpha band (R = -0.62). Due to these findings, this work suggests the possibility of using eye blinks measured from one sensor placed on the forehead as an unobtrusive measure correlating with neural mechanisms underpinning attentional demand
Feasibility of Screening Programs for Domestic Violence in Pediatric and Child and Adolescent Mental Health Services: A Literature Review
Each year, 275 million children worldwide are exposed to domestic violence (DV) and suffer negative mental and physical health consequences; however, only a small proportion receive assistance. Pediatricians and child psychiatrists can play a central role in identifying threatened children. We reviewed experiences of DV screening in pediatric and child and adolescent mental health services (CAMHS) to understand its feasibility and provide clues for its implementation. We performed bibliographic research using the Sapienza Library System, PubMed, and the following databases: MEDLINE, American Psychological Association PsycArticles, American Psychological Association PsycInfo, ScienceDirect, and Scopus. We considered a 20-year interval when selecting the articles and we included studies published in English between January 2000 and March 2021. A total of 23 out of 2335 studies satisfied the inclusion criteria. We found that the prevalence of disclosed DV ranged from 4.2% to 48%, with most prevalence estimates between 10% and 20%. Disclosure increases with a detection plan, which is mostly welcomed by mothers (70-80% acceptance rates). Written tools were used in 55% of studies, oral interviews in 40%, and computer instruments in 20%. Mixed forms were used in three studies (15%). The most used and effective tool appeared to be the Conflict Tactics Scale (CTS) (30% of studies). For young children, parental reports are advisable and written instruments are the first preference; interviews can be conducted with older children. Our research pointed out that the current literature does not provide practical clinical clues on facilitating the disclosure in pediatric clinics and CAMHS. Further studies are needed on the inpatient population and in the field of children psychiatry
Reaction of the Ambident Electrophile Dimethyl Carbonate with the Ambident Nucleophile Phenylhydrazine
To explore the ambident electrophilic reactivity of dimethyl carbonate (DMC), reactions with the ambident nucleophile phenylhydrazine were investigated. When a Brönsted base was used, selective carboxymethylation occurred at N-1, after that several other compounds were produced selectively utilizing various conditions. Formation of these compounds was explained by using the HardâSoft AcidâBase (HSAB) theory. Catalysis by some metal salts altered the reactivity of phenylhydrazine, which effected selective carboxymethylation at N-2 of phenylhydrazine instead
Phosgene-free carbamoylation of aniline via dimethyl carbonate
The synthesis of N-phenylcarbamate from aniline and dimethyl carbonate (DMC) in the presence of homogeneous, supported heterogeneous, and heterogeneous catalysts was investigated in batch conditions. First, a selection of homogeneous catalysts was studied and their reactivity in the same reaction conditions was compared to zinc acetate, a catalyst extensively used for this reaction. Then the best homogeneous catalysts were supported on silica or alumina, and the resulting heterogeneous supported catalysts were tested for the carbamoylation of aniline.
Finally, several heterogeneous catalysts were investigated. Zinc carbonate basic was shown to be the best catalyst, giving quantitative conversion and selectivity for the N-phenylcarbamate. Its catalytic activity was fully investigated taking into account substrate concentration, amount of catalysts, and temperature influence. Zinc carbonate was also shown to be recyclable, once it was recovered from the reaction mixture and calcinated
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