4,610 research outputs found
Scalar QED in AdS
We consider scalar QED with Nf flavors in AdSD. For D<4 the theory is strongly-coupled in the IR. We use the spin 1 spectral representation to compute and efficiently resum the bubble diagram in AdS, in order to obtain the exact propagator of the photon at large Nf. We then apply this result to compute the boundary four-point function of the charged operators at leading order in 1/Nf and exactly in the coupling, both in the Coulomb and in the Higgs phase. In the first case a conserved current is exchanged in the four-point function, while in the second case the current is absent and there is a pattern of double-trace scaling dimension analogous to a resonance in flat space. We also consider the BCFT data associated to the critical point with bulk conformal symmetry separating the two phases. Both in ordinary perturbation theory and at large Nf, in integer dimension D= 3 an IR divergence breaks the conformal symmetry on the boundary by inducing a boundary RG flow in a current-current operator
Olea europaea L-derived secoiridoids: Beneficial health effects and potential therapeutic approaches
Over the years, health challenges have become increasingly complex and global and, at the beginning of the 21st century, chronic diseases, including cardiovascular, neurological, and chronic respiratory diseases, as well as cancer and diabetes, have been identified by World Health Organization as one of the biggest threats to human health. Recently, antimicrobial resistance has also emerged as a growing problem of public health for the management of infectious diseases. In this scenario, the exploration of natural products as supplementation or alternative therapeutic options is acquiring great importance, and, among them, the olive tree, Olea europaea L, specifically leaves, fruits, and oil, has been increasingly investigated for its health promoting properties. Traditionally, these properties have been largely attributed to the high concentration of monounsaturated fatty acids, although, in recent years, beneficial effects have also been associated to other components, particularly polyphenols. Among them, the most interesting group is represented by Olea europaea L secoiridoids, comprising oleuropein, oleocanthal, oleacein, and ligstroside, which display anti-inflammatory, antioxidant, cardioprotective, neuroprotective and anticancer activities. This review provides an overview of the multiple health beneficial effects, the molecular mechanisms, and the potential applications of secoiridoids from Olea europaea L
A revised phytosociological nomenclature for the Italian Quercus cerris woods
This paper aims to revise the phytosociological nomenclature of the Quercus cerris woods occurring in Italy with particular attention to associations, subassociations, and suballiances. The syntaxa included in this revision were selected based on a physiognomical criterion, i.e., woods with dominance or codominance of Quercus cerris. The nomenclatural revision complied with the International Code of Phytosociological Nomenclature. Correct names and Authors' citations were considered for all the syntaxa analyzed (121), and, in most cases, other information about nomenclatural types, localities, synonyms, classification, and other notes was reported. As regards the alliance level, the correct application of the name Melittio albidae-Quercion frainetto ―whose original diagnosis and type-association occur in Italy― was discussed. In all, 31 syntaxon names were validated or described: two suballiances (Campanulo medii-Ostryenion carpinifoliae and Pulmonario apenninae-Carpinenion betuli), nine associations and 20 subassociations. Five lectotypes were also designated
New syntaxon names for the Italian Quercus cerris woods
Based on the results of a previous nomenclatural revision of the Italian Quercus cerris forests, 31 syntaxon names are here validated or described as new and 5 lectotypes are designated
Differential response to hepatic differentiation stimuli of amniotic epithelial cells isolated from four regions of the amniotic membrane
Human Amniotic Epithelial Cells (hAEC) isolated from term placenta are a promising source for regenerative medicine. However, it has long been debated whether the hAEC population consists of heterogeneous or homogeneous cells. In a previous study, we investigated the characteristics of hAEC isolated from four different regions of the amniotic membrane finding significant heterogeneity. The aim of this study was to evaluate the hepatic differentiation capability of hAEC isolated from these four regions. Human term placentae were collected after caesarean section and hAEC were isolated from four regions of the amniotic membrane (R1-R4, according to their relative distance from the umbilical cord) and treated in hepatic differentiation conditions for 14 days. hAEC-derived hepatocyte-like cells showed marked differences in the expression of hepatic markers: R4 showed higher levels of Albumin and Hepatocyte Nuclear Factor (HNF) 4α whereas R1 expressed higher Cytochrome P450 enzymes, both at the gene and protein level. These preliminary results suggest that hAEC isolated from R1 and R4 of the amniotic membrane are more prone to hepatic differentiation. Therefore, the use of hAEC from a specific region of the amniotic membrane should be taken into consideration as it could have an impact on the outcome of therapeutic applications
Hamiltonian study of the Generalized scalar-tensor theory with potential in a Bianchi type I model
We study the generalized scalar tensor theory with a potential in the Bianchi
type I model by using the ADM formalism. We examine the conditions for the
Universe to be in expansion, isotropic and with a positive potential at late
time in the Brans-Dicke and Einstein frames. In particular, we analyse the two
important cases where metric functions tend, in an asymptotic way, toward power
or exponential laws in the Einstein frame.Comment: 15 page
A comprehensive model integrating UTAUT and ECM with espoused cultural values for investigating users' continuance intention of using mobile payment
Zhao, Y., & Bacao, F. (2020). A comprehensive model integrating UTAUT and ECM with espoused cultural values for investigating users' continuance intention of using mobile payment. In Proceedings of the 2020 3rd International Conference on Big Data Technologies, ICBDT 2020 (pp. 155-161). (ACM International Conference Proceeding Series). Association for Computing Machinery. https://doi.org/10.1145/3422713.3422754Mobile payment (M-payment), as an emerging financial transaction method has been widely adopted in various contexts. In order to investigate the significance factors and espoused cultural moderators impacting users' M-payment continuance usage intention in China, this study proposes a comprehensive model integrating Unified Theory of Acceptance and Use of Technology (UTAUT) and Expectancy Confirmation Model (ECM) with trust variable espoused by Hofstede's cultural value to investigate factors affecting users' continuance intention of using M-payment. In addition, based on the proposed model, researchers can more accurately explain user' behavior not only corresponding technological perceptions, but also mental expectations and espoused cultural values for various technology continuance acceptance under different cultural background.publishersversionpublishe
On the semiclassical treatment of Hawking radiation
In the context of the semiclassical treatment of Hawking radiation we prove
the universality of the reduced canonical momentum for the system of a massive
shell self gravitating in a spherical gravitational field within the Painlev\'e
family of gauges. We show that one can construct modes which are regular on the
horizon both by considering as hamiltonian the exterior boundary term and by
using as hamiltonian the interior boundary term. The late time expansion is
given in both approaches and their time Fourier expansion computed to reproduce
the self reaction correction to the Hawking spectrum.Comment: 18 pages, LaTeX, Corrected typo
Pain associated with COVID-19 vaccination is unrelated to skin biopsy abnormalities
Previous clinical observations raised the possibility that COVID-19 vaccination might trigger a small-fibre neuropathy.Objectives:In this uncontrolled observational study, we aimed to identify small fibre damage in patients complaining of generalized sensory symptoms and pain after COVID-19 vaccination.Methods:We collected clinical data, including a questionnaire for assessing autonomic symptoms (Composite Autonomic Symptom Score-31), and investigated quantitative sensory testing (QST) and skin biopsy in 15 prospectively enrolled patients with generalized sensory symptoms and pain after COVID-19 vaccination. Nine patients complaining of orthostatic intolerance also underwent cardiovascular autonomic tests.Results:We found that all patients experienced widespread pain, and most of them (11 of 15) had a fibromyalgia syndrome. All patients had normal skin biopsy findings, and in the 9 patients with orthostatic intolerance, cardiovascular autonomic tests showed normal findings. Nevertheless, 5 patients had cold and warm detection abnormalities at the QST investigation.Conclusions:In our study, most patients complaining of generalized sensory symptoms and pain after COVID-19 vaccination had clinical and diagnostic test findings compatible with a fibromyalgia syndrome. Although the abnormal QST findings we found in 5 patients might be compatible with a small-fibre neuropathy, they should be cautiously interpreted given the psychophysical characteristics of this diagnostic test. Further larger controlled studies are needed to define precisely the association between small fibre damage and COVID-19 vaccination
Finite element and in vitro study on biomechanics behavior of endodontically treated premolars restored with direct or indirect composite restorations
Objectives of the study were to investigate biomechanical properties of severely compromised premolars restored with composite restorations using finite element analysis (FEA), and in vitro fracture resistance test. A 3-D model of an endodontically treated premolar was created in Solidworks. Different composite restorations were modelled (direct restoration-DR; endo-crown-EC; post, core, and crown-C) with two different supporting tissues: periodontal ligament/alveolar bone (B), and polymethyl methacrylate (PMMA). Models were two-point axially loaded occlusally (850 N). Von Mises stresses and strains were calculated. The same groups were further tested for static fracture resistance in vitro (n = 5, 6.0 mm-diameter ball indenter, vertical load). Fracture resistance data were statistically analyzed (p < 0.050). The highest stresses and strains in all FEA models were observed on occlusal and vestibular cervical surfaces, corresponding to fracture propagation demonstrated in vitro. C showed the lowest stress in dentin, while EC showed lower stresses and strains in crown cement. B models demonstrated larger high stress areas in the root than PMMA models. No significant differences
in fracture resistance (N) were observed between groups (DR: 747.7 ± 164.0, EC: 867.3 ± 108.1, C: 866.9 ± 126.3; p = 0.307). More conservative restorations seem a feasible alternative for endodontically treated premolars to conventional post-core-crown
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