814 research outputs found

    Search for fingerprints of disoriented chiral condensates in cosmic ray showers

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    Although the generation of disoriented chiral condensates (DCCs), where the order parameter for chiral symmetry breaking is misaligned with respect to the vacuum direction in isospin state, is quite natural in the theory of strong interactions, they have so far eluded experiments in accelerators and cosmic rays. If DCCs are formed in high-energy nuclear collisions, the relevant outcome are very large event-by-event fluctuations in the neutral-to-charged pion fraction. In this note we search for fingerprints of DCC formation in observables of ultra-high energy cosmic ray showers. We present simulation results for the depth of the maximum (XmaxX_{max}) and number of muons on the ground, evaluating their sensitivity to the neutral-to-charged pion fraction asymmetry produced in the primary interaction.Comment: 7 pages, 4 figure

    Decoherence in trapped ions due to polarization of the residual background gas

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    We investigate the mechanism of damping and heating of trapped ions associated with the polarization of the residual background gas induced by the oscillating ions themselves. Reasoning by analogy with the physics of surface electrons in liquid helium, we demonstrate that the decay of Rabi oscillations observed in experiments on 9Be+ can be attributed to the polarization phenomena investigated here. The measured sensitivity of the damping of Rabi oscillations with respect to the vibrational quantum number of a trapped ion is also predicted in our polarization model.Comment: 26 pdf pages with 5 figures, http://www.df.ufscar.br/~quantum

    Cenário E Perspectiva Da Produção Científica Sobre Competência Em Informação (coinfo) No Brasil: Estudo Da Produção No âmbito Da Ancib

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    Search highlight in the field of Information Science in Brazil, the importance of the publications generated by scientific events, specifically the scope of information literacy (Competência em Informação - CoInfo, in Portuguese), analyzing the work and the production of its main scientific society, the Associação Nacional de Pesquisa e Pós-Graduação em Ciência da Informação - ANCIB. Presents the results of research that involved the document corpus published in the editions of the Encontro Nacional de Pesquisa e Pós-Graduação em Ciência da Informação - Enancib, annual scientific agenda ANCIB, watching literature produced by scientific work on CoInfo presented in all Anais of the Enancib in the period 1994-2015, identifying theme insertion in all of its major working groups. The research used exploratory and descriptive approach, involving documentary and historical research. The search was carried out in the event portal ANCIB-Enancib, from the selection of the works related to the theme CoInfo and seven related terms: information literacy, competência informacional, alfabetização informacional, aprendizagem informacional, alfabetização em informação, letramento informacional, user education. For measurement data we used the Bardin technique. The results show that as of 2009 there is an increase in the production of work on CoInfo presented in Enancib, indicating that the spaces commonly used for the application of methodologies are libraries. These results also show that the document corpus dealing with the subject and the growing interest of researchers for it, coupled with the possibilities of seminars involving this theme in focus in recent programming Post-Enancib's, provides a very promising future vision for the studies, research and the effective consolidation of CoInfo in the field of Information Science in Brazil, and its visibility. In conclusion, presents the efforts made by various institutions for the development of CoInfo in Brazil in international impact event.26315116

    Glucosylpolyphenols as Inhibitors of Aβ-Induced Fyn Kinase Activation and Tau Phosphorylation: Synthesis, Membrane Permeability, and Exploratory Target Assessment within the Scope of Type 2 Diabetes and Alzheimer's Disease

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    Despite the rapidly increasing number of patients suffering from type 2 diabetes, Alzheimer's disease, and diabetes-induced dementia, there are no disease-modifying therapies that are able to prevent or block disease progress. In this work, we investigate the potential of nature-inspired glucosylpolyphenols against relevant targets, including islet amyloid polypeptide, glucosidases, and cholinesterases. Moreover, with the premise of Fyn kinase as a paradigm-shifting target in Alzheimer's drug discovery, we explore glucosylpolyphenols as blockers of Aβ-induced Fyn kinase activation while looking into downstream effects leading to Tau hyperphosphorylation. Several compounds inhibit Aβ-induced Fyn kinase activation and decrease pTau levels at 10 μM concentration, particularly the per-O-methylated glucosylacetophloroglucinol and the 4-glucosylcatechol dibenzoate, the latter inhibiting also butyrylcholinesterase and β-glucosidase. Both compounds are nontoxic with ideal pharmacokinetic properties for further development. This work ultimately highlights the multitarget nature, fine structural tuning capacity, and valuable therapeutic significance of glucosylpolyphenols in the context of these metabolic and neurodegenerative disorders.European Commission GA 612347Fundação para a Ciência e a Tecnologia SFRH/BD/93170/2013, SFRH/BD/116614/2016, PD/BD/142847/2018, SFRH/BD/145600/2019, CEECIND/03414/2018, CEECIND/02300/2017, UIDB/00100/2020, UIDB/04046/2020, UIDB/04378/2020, IF/00780/2015Gobierno de España CTQ2016-78703-PJunta de Andalucía FQM13

    Altered glucose homeostasis and hepatic function in obese mice deficient for both kinin receptor genes

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    The Kallikrein-Kinin System (KKS) has been implicated in several aspects of metabolism, including the regulation of glucose homeostasis and adiposity. Kinins and des-Arg-kinins are the major effectors of this system and promote their effects by binding to two different receptors, the kinin B2 and B1 receptors, respectively. To understand the influence of the KKS on the pathophysiology of obesity and type 2 diabetes (T2DM), we generated an animal model deficient for both kinin receptor genes and leptin (obB1B2KO). Six-month-old obB1B2KO mice showed increased blood glucose levels. Isolated islets of the transgenic animals were more responsive to glucose stimulation releasing greater amounts of insulin, mainly in 3-month-old mice, which was corroborated by elevated serum C-peptide concentrations. Furthermore, they presented hepatomegaly, pronounced steatosis, and increased levels of circulating transaminases. This mouse also demonstrated exacerbated gluconeogenesis during the pyruvate challenge test. The hepatic abnormalities were accompanied by changes in the gene expression of factors linked to glucose and lipid metabolisms in the liver. Thus, we conclude that kinin receptors are important for modulation of insulin secretion and for the preservation of normal glucose levels and hepatic functions in obese mice, suggesting a protective role of the KKS regarding complications associated with obesity and T2DM

    Multicenter, International Study of MIC/ MEC Distributions for definition of epidemiological cutoff values for sporothrix species identified by molecular methods

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    Clinical and Laboratory Standards Institute (CLSI) conditions for testing the susceptibilities of pathogenic Sporothrix species to antifungal agents are based on a collaborative study that evaluated five clinically relevant isolates of Sporothrix schenckii sensu lato and some antifungal agents. With the advent of molecular identification, there are two basic needs: to confirm the suitability of these testing conditions for all agents and Sporothrix species and to establish species-specific epidemiologic cutoff values (ECVs) or breakpoints (BPs) for the species. We collected available CLSI MICs/minimal effective concentrations (MECs) of amphotericin B, five triazoles, terbinafine, flucytosine, and caspofungin for 301 Sporothrix schenckii sensu stricto, 486 S. brasiliensis, 75 S. globosa, and 13 S. mexicana molecularly identified isolates. Data were obtained in 17 independent laboratories (Australia, Europe, India, South Africa, and South and North America) using conidial inoculum suspensions and 48 to 72 h of incubation at 35°C. Sufficient and suitable data (modal MICs within 2-fold concentrations) allowed the proposal of the following ECVs for S. schenckii and S. brasiliensis, respectively: amphotericin B, 4 and 4 /ml; itraconazole, 2 and 2 μg/ml; posaconazole, 2 and 2 μg/ml; and voriconazole, 64 and 32 μg/ml. Ketoconazole and terbinafine ECVs for S. brasiliensis were 2 and 0.12 μg/ml, respectively. Insufficient or unsuitable data precluded the calculation of ketoconazole and terbinafine (or any other antifungal agent) ECVs for S. schenckii, as well as ECVs for S. globosa and S. mexicana. These ECVs could aid the clinician in identifying potentially resistant isolates (non-wild type) less likely to respond to therapy.A. Espinel-Ingroff, D. P. B. Abreu, R. Almeida-Paes, R. S. N. Brilhante, A. Chakrabarti, A. Chowdhary, F. Hagen, S. Córdoba, G. M. Gonzalez, N. P. Govender, J. Guarro, E. M. Johnson, S. E. Kidd, S. A. Pereira, A. M. Rodrigues, S. Rozental, M. W. Szeszs, R. Ballesté Alaniz, A. Bonifaz, L. X. Bonfietti, L. P. Borba-Santos, J. Capilla, A. L. Colombo, M. Dolande, M. G. Isla, M. S. C. Melhem, A. C. Mesa-Arango, M. M. E. Oliveira, M. M. Panizo, Z. Pires de Camargo, R. M. Zancope-Oliveira, J. F. Meis, J. Turnidge
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