4,141 research outputs found
Investigating The Physics Case of Running a B-Factory at the Y(5S) Resonance
We discuss the physics case of a high luminosity B-Factory running at the
Y(5S) resonance. We show that the coherence of the B meson pairs is preserved
at this resonance, and that Bs can be well distinguished from Bd and charged B
mesons. These facts allow to cover the physics program of a traditional
B-Factory and, at the same time, to perform complementary measurements which
are not accessible at the Y(4S). In particular we show how, despite the
experimental limitations in performing time-dependent measurements of Bs
decays, the same experimental information can be extracted, in several cases,
from the determination of time-integrated observables. In addition, a few
examples of the potentiality in measuring rare Bs decays are given. Finally, we
discuss how the study of Bs meson will improve the constraints on New Physics
parameters in the Bs sector, in the context of the generalized Unitarity
Triangle analysis.Comment: 47 pages, 22 figure
The regulation of exosome function in the CNS: implications for neurodegeneration
Exosomes are nanovesicles that have been shown to regulate neuronal development and regeneration, and modulate synaptic function
Pion Number Fluctuations and Correlations in the Statistical System with Fixed Isospin
The statistical system of pions with zero total isospin is studied. The
suppression effects for the average yields due to isospin conservation are the
same for , and . However, a behavior of the corresponding
particle number fluctuations are different. For neutral pions there is the
enhancement of the fluctuations, whereas for charged pions the isospin
conservation suppresses fluctuations. The correlations between the numbers of
charged and neutral pions are observed for finite systems. This causes a
maximum of the total pion number fluctuations for small systems. The
thermodynamic limit values for the scaled variances of neutral and charged
pions are calculated. The enhancements of the fluctuations due to Bose
statistics are found and discussed
Graphene-based nanomaterials for tissue engineering in the dental field
The world of dentistry is approaching graphene-based nanomaterials as substitutes for tissue engineering. Apart from its exceptional mechanical strength, electrical conductivity and thermal stability, graphene and its derivatives can be functionalized with several bioactive molecules. They can also be incorporated into different scaffolds used in regenerative dentistry, generating nanocomposites with improved characteristics. This review presents the state of the art of graphene-based nanomaterial applications in the dental field. We first discuss the interactions between cells and graphene, summarizing the available in vitro and in vivo studies concerning graphene biocompatibility and cytotoxicity. We then highlight the role of graphene-based nanomaterials in stem cell control, in terms of adhesion, proliferation and differentiation. Particular attention will be given to stem cells of dental origin, such as those isolated from dental pulp, periodontal ligament or dental follicle. The review then discusses the interactions between graphene-based nanomaterials with cells of the immune system; we also focus on the antibacterial activity of graphene nanomaterials. In the last section, we offer our perspectives on the various opportunities facing the use of graphene and its derivatives in associations with titanium dental implants, membranes for bone regeneration, resins, cements and adhesives as well as for tooth-whitening procedure
Optimization of SPME/GC-MS analytical method using Response Surface Methodology for pesticides monitoring in aqueous matrices
Emerging pollutants are a type of contaminants that can occur in water sources. They can be defined as any synthetic or naturally occurring chemical or microorganism that is not
usually monitored or regulated in the environment and have the potential to cause detrimental ecological and human health impacts. These compounds can be found in the
environment in very low concentrations, at scales ranging from nanograms to micrograms per liter.
Pesticides are an important group of emerging pollutants due to the continuous increase in their use in agricultural production process to control diseases, pests and weedsThe authors are grateful to the Foundation for Science and Technology (FCT,
Portugal) for financial support by national funds FCT/MCTES to CIMO
(UIDB/00690/2020).info:eu-repo/semantics/publishedVersio
Interleukin-2 inhalation therapy in renal cell cancer: a case report and review of the literature
Renal cell carcinoma (RCC) is the most common malignancy of the kidney. One third of RCC presents metastatic disease at the time of diagnosis, usually leading to a fatal outcome. Small response rates were seen with most cytotoxic agents including gemcitabine and vinorelbine, whereas systemic therapy with high doses of interleukin 2 (IL-2) has been shown to provide durable complete remissions. However, in consideration of its severe toxicity, IL-2 immunotherapy is restricted to selected patients. Aerosol IL-2 has been introduced as an alternative therapy in cancer patients. However, only very few data are available on its use in patients with pulmonary metastatic RCC. This paper briefly summarizes current clinical experience with the use of inhaled IL-2 therapy, either as a single therapy or in combination with other treatments. In addition, we report on a male patient with pulmonary metastasized RCC who achieved a durable complete response to combined gemcitabine/vinorelbine and interleukin-2 inhalation therapy
Biological effects of a software-controlled voltage pulse generator (PhyBack PBK-2C) on the release of vascular endothelial growth factor (VEGF)
Electrical stimulation (ES) may induce vascular permeability and physiological angiogenesis. ES of rat muscles significantly increases the microvessel density and vascular endothelial growth factor (VEGF) protein levels. Thus, a pilot study was designed to analyze the effects of low-voltage electric impulses on VEGF levels in patients with dystrophic ulcers
Protective effects of exosomes derived from lyophilized porcine liver against acetaminophen damage on HepG2 cells
Background: Recently, extracellular vesicles have come to the fore following their emerging role in cell communication, thanks to their ability to reach cells into the human body without dissipating their cargo, transferring biological active molecules, such as proteins, nucleic acids, lipids, etc. They appear as a promising tool in medicine, because of their capability to modulate cellular response in recipient cells. Moreover, a considerable number of publications suggests that exosome uptake is selective but not specific, and it can cross species and cell-type boundaries. This study aims to explore the potential role of porcine liver derived extracellular vesicles, exosomes in particular, to protect human cells from acute damage induced by acetaminophen. Methods: Extracellular vesicles were isolated from porcine lyophilized liver using polymer-based precipitation and a further enrichment was performed using affinity beads. The effects of obtained fractions, total extracellular vesicles and enriched extracellular vesicles, were assessed on human liver derived HepG2 cells. Cell growth and survival were tested, with MTT and area coverage analysis designed by us, as well as protein expression, with immunofluorescence and Western blot. Oxidative stress in live cells was also measured with fluorogenic probes. Results: After proving that porcine extracellular vesicles did not have a toxic effect on HepG2, quite the contrary total extracellular vesicle fraction improved cell growth, we investigated their protective capability with a preconditioning strategy in APAP-induced damage. EVs displayed not only the ability to strongly modulate cell survival responses, but they also were able to boost cell cycle progression. Conclusions: Extracellular vesicles derived from farm animal food derivatives are able to modulate human hepatic cell metabolism, also improving cell survival in a damaged context
First bolometric measurement of the two neutrino double beta decay of Mo with a ZnMoO crystals array
The large statistics collected during the operation of a ZnMoO array, for
a total exposure of 1.3 kg day of Mo, allowed the first
bolometric observation of the two neutrino double beta decay of Mo. The
observed spectrum of each crystal was reconstructed taking into account the
different background contributions due to environmental radioactivity and
internal contamination. The analysis of coincidences between the crystals
allowed the assignment of constraints to the intensity of the different
background sources, resulting in a reconstruction of the measured spectrum down
to an energy of 300 keV. The half-life extracted from the data is
T= [7.15 0.37 (stat) 0.66 (syst)] 10
y.Comment: 6 pages, 2 figure, Accepted for publication in Journal of Physics G:
Nuclear and Particle Physic
Explorando a construção de identidades nas interações entre professor e aluno na aula de lÃngua estrangeira: reflexões para a prática didática
O presente artigo propõe-se obter informações sobre o estilo pedagógico de um professor em formação a partir do estudo dos atos de identidade, com os quais os falantes, nas trocas comunicativas, revelam sua identidade e o papel social que almejam alcançar e que são produzidos pelos aprendizes de italiano lÃngua estrangeira na aula de lÃngua. Como referência teórica e metodológica, adotaremos uma abordagem interessada na observação do funcionamento interacional como espaço de mobilização e de construção das competências de linguagem em situações pedagógicas. A análise, realizada com base em macrounidade chamadas passos pedagógico-didáticos, nos permitiu identificar algumas necessidades do professor quanto aos aspectos que ele é capaz ou não de explorar em sala de aula e a consequente construção de planos globais de formação.This article studies acts of identity – the linguistic comments with which speakers, in communicative exchanges, reveal their identity and the social role they wish to play – produced in interactions between the teacher and the student, by learners whose mother tongue is typologically similar to the foreign language they are learning. The analysis of the identity roles performed by learners in foreign language classrooms, in relation to the pedagogical approaches, allow us to identify some necessary characteristics of the teacher as to the aspects they are able or unable to explore in the classroom and the consequent construction of global teacher education plans. As the theoretical and methodological framework, we will follow an approach based on references extracted from studies covering the training of foreign language teachers
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