534 research outputs found
Toward a linguistically grounded dialog model for chatbot design
The increasing interest in various types of conversational interfaces has been supported by a progressive standardization of the technological frameworks used to build them. However, the landscape of available methodological frameworks for designing conversations is much more fragmented. We propose a highly generalizable methodology for designing conversational flows rooted in a functionalist-pragmatics perspective, with an explicit adherence to a conversationalist approach. In parallel, we elaborate a practical-procedural workflow for undertaking chatbots projects in which we situate the theoretical starting point. At last, we elaborate a general case- study on which we transpose the identified approach in Italian language and using one of the most authoritative NLU platforms
Unique Solutions to Hartree-Fock Equations for Closed Shell Atoms
In this paper we study the problem of uniqueness of solutions to the Hartree
and Hartree-Fock equations of atoms. We show, for example, that the
Hartree-Fock ground state of a closed shell atom is unique provided the atomic
number is sufficiently large compared to the number of electrons. More
specifically, a two-electron atom with atomic number has a unique
Hartree-Fock ground state given by two orbitals with opposite spins and
identical spatial wave functions. This statement is wrong for some , which
exhibits a phase segregation.Comment: 18 page
Structural characterization of a human Fc fragment engineered for lack of effector functions
Human Fc fragments containing the L234F/L235E/P331S triple mutation exhibit a dramatic decrease in their binding to several effector molecules (CD64, CD32A, CD16 and C1q). The three-dimensional structure of such a mutated fragment reveals that these broad-ranging functional effects are not caused by major structural rearrangements in the Fc moiety
Chemical Characterization and Cytotoxic and Antioxidant Activity Evaluation of the Ethanol Extract from the Bulbs of Pancratium maritimun Collected in Sicily
P. maritimum L., belonging to the Amaryllidaceae family, is a species that grows on beaches and coastal sand dunes mainly on both sides of the Mediterranean Sea and Black Sea, the Middle East, and up to the Caucasus region. It has been largely investigated due to its several interesting biological properties. With the aim of providing new insights into the phytochemistry and pharmacology of this species, the ethanolic extract of the bulbs from a local accession, not previously studied, growing in Sicily (Italy), was investigated. This chemical analysis, performed by mono- and bi-dimensional NMR spectroscopy, as well as LC-DAD-MSn, allowed to identify several alkaloids, three of which were never detected in the genus Pancratium. Furthermore, the cytotoxicity of the preparation was assessed in differentiated human Caco-2 intestinal cells by trypan blue exclusion assay, and its antioxidant potential was evaluated using the DCFH-DA radical scavenging method. The results obtained demonstrate that P. maritimum bulbs’ extract exerts no cytotoxic effect and is able to remove free radicals at all the concentrations tested
Crystallization and preliminary X-ray diffraction analysis of the complex between a human anti-interferon antibody fragment and human interferon α-2A
Crystals of the complex between the Fab fragment of a human anti-interferon α therapeutic antibody and human interferon α-2A have been obtained and diffracted to 3.0 Å resolution
Phytochemical investigations on Artemisia alba Turra growing in the North-East of Italy
Artemisia alba Turra (Asteraceae) is an Euro-Mediterranean plant used in Veneto (North-East of Italy) as traditional medicine for the treatment of various diseases. A. alba is a taxonomically problematic species, characterized by common polymorphism leading to a quite high variability in secondary metabolites content. Nonetheless, the phytochemical knowledge on its phytoconstituents, especially non-volatile components, is limited. In the present paper, the phytochemical composition of a tincture obtained from the aerial parts of A. alba growing in Veneto is presented. Extensive chromatographic separations led to the isolation of three new sesquiterpene derivatives, whose structures were elucidated by 1D and 2D NMR experiments and mass spectrometry. Furthermore, flavonoid composition and volatile constituents of the tincture of A. alba were preliminary studied by HPLC-MSn and GC-MS, respectivel
Insights into the 3D In Vitro Permeability and In Vivo Antioxidant Protective Effects of Kiwiberry Leaf Extract: A Step Forward to Human Nutraceutical Use
Actinidia arguta (Siebold & Zucc.) Planch. ex Miq. (kiwiberry) leaves are a source of phenolic compounds with pro-health biological effects, such as antioxidant and anti-inflammatory activities. Despite the huge number of studies reporting the composition of A. arguta leaves, no in vitro or in vivo studies explore its potential use as nutraceutical ingredient based on these activities. Therefore, this study aims to characterize the safety profile of kiwiberry leaf extracts using in vitro and in vivo approaches through the assessment of intestinal cell viability (Caco-2 and HT29-MTX), 3D intestinal permeation, and, most important, the redox markers, biochemical profile and liver and kidney function effects after the animal assays. Briefly, wistar rats were orally treated for 7 days with kiwiberry leaf extracts (50 and 75 mg/kg bw), water (negative control), or vitamin C (positive control). The cell viability was above 90% at 1000 μg/mL for both cells. Coumaroyl quinic acid and rutin achieved a permeation higher than 25% in the 3D intestinal model. The animal studies confirmed the extracts’ ability to increase superoxide dismutase, glutathione peroxidase, and catalase content in animals’ livers and kidneys while simultaneously decreasing the triglycerides content. This study highlighted the antioxidant capacity of kiwiberry leaf extracts, ensuring their efficacy and safety as a nutraceutical ingredientThis research was funded by project EXPL/BAA-GR/0663/2021—Kiwi4Health—Exploring
the Eco-Innovative Re-Use of Kiwiberry, supported by national funds by FCT/MCTES and by the
projects UIDB/50006/2020 and UIDP/50006/2020 through national funds. This work was also
financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of
the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular
Biosciences—UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for
Health and Bioeconomy—i4HB. The authors are thankful to Minikiwi Land for the samples and all availability
during this work. Ana Margarida Silva is thankful for the Ph.D. grant (SFRH/BD/144994/2019)
financed by POPH-QREN and subsidized by the European Science Foundation and Ministério da
CiĂŞncia, Tecnologia e Ensino Superior. Francisca Rodrigues (CEECIND/01886/2020) is thankful for
her contract financed by FCT/MCTES—CEEC Individual Program Contract.info:eu-repo/semantics/publishedVersio
A threshold phenomenon for embeddings of into Orlicz spaces
We consider a sequence of positive smooth critical points of the
Adams-Moser-Trudinger embedding of into Orlicz spaces. We study its
concentration-compactness behavior and show that if the sequence is not
precompact, then the liminf of the -norms of the functions is greater
than or equal to a positive geometric constant.Comment: 14 Page
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