5,091 research outputs found

    Thermal entanglement witness for materials with variable local spin lengths

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    We show that the thermal entanglement in a spin system using only magnetic susceptibility measurements is restricted to the insulator materials. We develop a generalization of the thermal entanglement witness that allows us to get information about the system entanglement with variable local spin lengths that can be used experimentally in conductor or insulator materials. As an application, we study thermal entanglement for the half-filled Hubbard model for linear, square and cubic clusters. We note that it is the itinerancy of electrons that favors the entanglement. Our results suggest a weak dependence between entanglement and external spin freedom degrees.Comment: 4 pages, 3 figure

    Grande Queimado numa Unidade de Cuidados Intensivos Pediátricos – Experiência de 20 Anos

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    Introdução: A abordagem inicial do grande queimado até à sua estabilização hemodinâmica e hidroeletrolítica é fundamental para diminuir a morbimortalidade. Material e Métodos: Estudo retrospectivo, descritivo e analítico, de todos os internamentos por queimadura numa Unidade de Cuidados Intensivos Pediátricos durante o período de 20 anos (Abril/1991 a Dezembro/2010). Avaliaram -se parâmetros nosodemográficos, agente causal, gravidade e extensão da queimadura, procedimentos, terapêutica, complicações e resultados. Resultados: Ocorreram 137 internamentos por queimadura correspondentes a 123 doentes e a 1,8% do total de internamentos na UCIP. A mediana de idade foi 3,6 anos e 62,4% era do sexo masculino. Verificou -se maior incidência em Agosto (13,0%). Foram agentes da queimadura: líquido fervente (38,1%), fogo (38,1%) e eletricidade (23,9%). A mediana da superfície corporal queimada foi de 30% (0,5 -92,0%), com queimaduras do terceiro grau em 59,0% dos doentes. Necessitaram de ventilação mecânica 45,5% e de cateter venoso central 64,2% dos doentes. As complicações incluíram: sépsis (29,2%), falência respiratória (21,1%), falência cardiovascular (16,5%) e falência multiorgânica (18,8%). Verificou -se melhoria em 88,6% dos casos e ocorreram 10 óbitos (8,1%), nove dos quais nos primeiros 10 anos do estudo e nove devido a causa infeciosa. No entanto, o score avaliador do risco de mortalidade (PRISM), índice de intervenção terapêutica (TISS) e o risco de probabilidade de morte (RPM) foram mais elevados no segundo decénio. Conclusões: Nos últimos anos do estudo, apesar do maior número de admissões e da sua maior gravidade, verificou -se uma diminuição do número de mortes, o que poderá dever-se à melhoria dos cuidados prestados

    Polytopality and Cartesian products of graphs

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    We study the question of polytopality of graphs: when is a given graph the graph of a polytope? We first review the known necessary conditions for a graph to be polytopal, and we provide several families of graphs which satisfy all these conditions, but which nonetheless are not graphs of polytopes. Our main contribution concerns the polytopality of Cartesian products of non-polytopal graphs. On the one hand, we show that products of simple polytopes are the only simple polytopes whose graph is a product. On the other hand, we provide a general method to construct (non-simple) polytopal products whose factors are not polytopal.Comment: 21 pages, 10 figure

    Influenza B-Associated Atypical Hemolytic Uremic Syndrome

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    Introduction: Influenza A infections have been described to cause secondary hemolytic uremic syndrome and to trigger atypical hemolytic uremic syndrome (aHUS) in individuals with an underlying genetic complement dysregulation. To date, Influenza B has only been reported to trigger aHUS in 2 patients. In 61% of aHUS cases, mutations are found in H, B and I factors, membrane cofactor protein (MCP), C3 and thrombomodulin. MCP (CD46) mutations account for 10-15% of cases. Clinical Case: A 13-year-old boy was transferred to a terciary pediatric centre with acute renal lesion in the context of HUS. Evidence was found for Influenza B infection and results for other etiologic agents were negative. He was treated with Oseltamivir for 5 days. Etiologic study revealed decreased C ́3 (0,81 g/L), normal C ́4 (0,27 g/L) and all antibodies were negative: anti-Beta2 GP1 IgG / IgM, anti-cardiolipine IgG / IgM, anti-neutrophil-citoplasm-PR3 and MPO. Alternate complement pathway study (AH 50) were 112 % of normal value (reference value >70%) and ADAMTS 13 activity were 0.79 (values above 0.67 may be found in aSHU as well as other microangiopathic trombopathies). Molecular study of complement including 11 genes (CFH, CD46 (MCP), CFI, C3, THBD, CFB,CFHR5, CFHR1 CFHR3, CFHR4, DGKE) found a pathogenic heterozygotic missense variant on CD46 (MCP) gene, c.554A>G, p.Asp185Gly, associated with aHUS. Conclusions: aHUS patients should be screened for all known disease-associated genes. Screening should not be stopped after finding a mutation to avoid missing other genetic susceptibility factors influencing disease phenotype, particularly in patients with MCP or CFI mutations, because they have a higher probability of also carrying mutation in another gene than patients with CFHor C3 mutations. Influenza B is a trigger for aHUS and might be underreported as such. Influenza vaccination may protect patients at risk.info:eu-repo/semantics/publishedVersio

    Nephrolithiasis in a Portuguese Pediatric Population

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    Introduction and Aims: Nephrolithiasis incidence in children has increased considerably. It is associated with substantial morbidity, recurrence and increased adulthood cardiovascular risk and chronic kidney disease. A thorough investigation is essential, as rare forms of urolithiasis have increased risk of renal failure. We aim to determine the epidemiology and outcomes of a pediatric population with nephrolithiasis presented in a nephrology unit of a tertiary centre. Methods: Retrospective study of the records of all children (<18 years) with nephrolithiasis diagnosis between 2008‑17. Clinical features, etiology, recurrence, treatment, and outcomes were evaluated and compared throughout the study period through two equal periods (2008‑12 versus 2013‑17). Results: We identified 80 cases: isolated nephrolithiasis (86%) and associated with nephrocalcinosis (14%). Mean follow‑up was 36 months (14–120). Median age at presentation was 8.6 years [3 months – 17 years]: 21% < 2 years‑old and 46% ≥ 10 years. The annual ratio of referrals for nephrolithiasis increased on average 1.2% per year [0.3‑11.8%]. Multiple etiological factors were present in 34%. A metabolic abnormality was identified in 54%: hypocitraturia (34%), hypercalcuria (24%), hyperoxaluria (15%), hyperuricosuria (15%) and cystinuria (1%), without age predominance (p=0.2). Urinary tract infection (24%) was the next most significant etiology and was more frequent below 2 years of age (p=0.001) and associated with struvite calculi (p=0.033). Median age at diagnosis was significantly lower in the study’s first half (5 vs 10 years; p=0.019) and an infectious etiology was more frequent (p=0.043). In a logistic‑regression analysis, a family history of nephrolithiasis was associated with a metabolic cause (p<0.01). Sixty‑three percent became stone free and 24% had recurrence. Discussion: Nephrolithiasis new referrals gradually increased throughout the study period. The most common etiology was metabolic, which is usually responsible for nephrolithiasis appearance and its recurrence, emphasizing the need for a complete evaluation.info:eu-repo/semantics/publishedVersio

    Prognostic impact of invasive hemodynamic evaluation in patients with pulmonary arterial hypertension

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    Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: [email protected]: Invasive hemodynamic evaluation is a fundamental diagnostic method in patients with pulmonary hypertension (PH). However, its prognostic value in this group of patients is not fully established. Purpose: To assess the prognostic impact of hemodynamic parameters of right catheterization in patients with PH. Methods: Prospective observational study of patients with PH undergoing right and left catheterization for diagnostic confirmation and functional evaluation during vasoreactivity test. Only patients with mean pulmonary arterial pressure (PAP) >25 mmHg considered not secondary to left heart disease were included. A basal evaluation of the conventional hemodynamic parameters, left and right ventricular function indexes, pulmonary and systemic vascular resistance indexes were performed and they were re-evaluated during vasoreactivity test. The parametres were analysed and related with overall mortality and with cardiac death or hospitalization during clinical follow-up by Multivariate regression analysis of Cox. Results: A total of 68 patients were included (71% females, mean age 53±17 years), 81% of whom were from group 1 (NICE) and 15% from group IV. The mean value of mean pulmonary artery pressure was 47±16mmHg and mean right atrial pressure was 11±7mmHg. During a median follow-up of 34 months, 7 patients (10%) died and 25 (37%) were hospitalized for heart failure. Of all hemodynamic parameters, the only independent predictor of mortality was the mean right atrial pressure, for each 1mmHg rise, mortality risk increased by 12% (hazard ratio (HR): 1, 12; 95% CI 1.02–1.23; p=0.018) and the risk of death or hospitalization for cardiac causes was 17% (HR: 1.17, 95% CI: 1.00–1.37, P=0.050). The prognosis was not influenced by the demonstration of pulmonary arterial vasoreactivity, magnitude of PAP elevation or pulmonary vascular resistance. Conclusion: In patients with PH, invasive hemodynamic evaluation offers an addictional value in prognostic stratification. In particular, measurement of mean right atrial pressure has been shown to be an independent predictor of mortality. On the other hand, other parameters such as pulmonary arterial vasoreactivity, although important in the definition of the therapeutic strategy, did not have an impact on the risk of death or hospitalization.info:eu-repo/semantics/publishedVersio

    Cosmology with a SKA HI intensity mapping survey

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    Advancing Astrophysics with the Square Kilometre Array June 8-13, 2014 Giardini Naxos, ItalyHI intensity mapping (IM) is a novel technique capable of mapping the large-scale structure of the Universe in three dimensions and delivering exquisite constraints on cosmology, by using HI as a biased tracer of the dark matter density field. This is achieved by measuring the intensity of the redshifted 21cm line over the sky in a range of redshifts without the requirement to resolve individual galaxies. In this chapter, we investigate the potential of SKA1 to deliver HI intensity maps over a broad range of frequencies and a substantial fraction of the sky. By pinning down the baryon acoustic oscillation and redshift space distortion features in the matter power spectrum – thus determining the expansion and growth history of the Universe – these surveys can provide powerful tests of dark energy models and modifications to General Relativity. They can also be used to probe physics on extremely large scales, where precise measurements of spatial curvature and primordial non-Gaussianity can be used to test inflation; on small scales, by measuring the sum of neutrino masses; and at high redshifts where non-standard evolution models can be probed. We discuss the impact of foregrounds as well as various instrumental and survey design parameters on the achievable constraints. In particular we analyse the feasibility of using the SKA1 autocorrelations to probe the large-scale signal.Web of Scienc

    Evaluation of the Antimicrobial Activity of the Decoction of Tropidurus hispidus (Spix, 1825) and Tropidurus semitaeniatus (Spix, 1825) Used by the Traditional Medicine

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    Tropidurus hispidus and Tropidurus semitaeniatus are two lizard species utilized in traditional medicine in Northeast Brazil. Their medicinal use includes diseases related with bacterial infections such as tonsillitis and pharyngitis. They are used in the form of teas (decoctions) for the treatment of illnesses. In this work, we evaluated the antimicrobial activity of the decoctions of T. hispidus (DTH) and T. semitaeniatus (DTS) against bacterial strains, namely, standard and multiresistant Escherichia coli, Staphylococus aureus, and Pseudomonas aureuginosa, alone and in combination with aminoglycoside antibiotics. The decoctions were prepared using the whole body of the dried lizards, and the filtrate was frozen and lyophilized. When tested alone, the samples did not demonstrate any substantial inhibition of bacterial growth. However, in combination with antibiotics as aminoglycosides, decoctions reduced the minimal inhibitory concentration (MIC) of the assayed antibiotics against multiresistant strains of S. aureus and P. aureuginosa. Chemical prospecting tests revealed the presence of alkaloids in DTS. This is the first study evaluating the medicinal efficacy of T. hispidus and T. semitaeniatus and contributes to the list of new sources of medicines from natural products of animal origin

    microstructure evolution during heat treatments

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    Funding Information: Authors acknowledge the Portuguese Fundação para a Ciência e a Tecnologia (FCT – MCTES) for its financial support via the project UID/EMS/00667/2019 (UNIDEMI). JPO acknowledges funding by national funds from FCT - Fundação para a Ciência e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020 , UIDP/50025/2020 and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication – i3N. Funding of CENIMAT/i3N by national funds through the FCT-Fundação para a Ciência e a Tecnologia, I.P., within the scope of Multiannual Financing of R&D Units, reference UIDB/50025/2020–2023 is also acknowledge. FWCF acknowledges Fundação para a Ciência e a Tecnologia ( FCT-MCTES ) for funding the Ph.D. Grant 2022.13870. BD. The authors acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Beamtime was allocated for proposal I-20210986 EC. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. This activity has received funding from the European Institute of Innovation and Technology (EIT) Raw Materials through the project Smart WAAM: Microstructural Engineering and Integrated Non-Destructive Testing. YZ acknowledges the National Natural Science Foundation of China ( 51601091 ), the Natural Science Foundation of Jiangsu Province ( BK 20160826 ), the Six Talent Peaks Project of Jiangsu Province ( 2017-XCL-051 ), the Fundamental Research Funds for the Central Universities ( 30917011106 ), and Key Research and Development Plan of Jiangsu Province ( BE 2020085 ). Funding Information: Authors acknowledge the Portuguese Fundação para a Ciência e a Tecnologia (FCT – MCTES) for its financial support via the project UID/EMS/00667/2019 (UNIDEMI). JPO acknowledges funding by national funds from FCT - Fundação para a Ciência e a Tecnologia, I.P. in the scope of the projects LA/P/0037/2020, UIDP/50025/2020 and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication – i3N. Funding of CENIMAT/i3N by national funds through the FCT-Fundação para a Ciência e a Tecnologia, I.P. within the scope of Multiannual Financing of R&D Units, reference UIDB/50025/2020–2023 is also acknowledge. FWCF acknowledges Fundação para a Ciência e a Tecnologia (FCT-MCTES) for funding the Ph.D. Grant 2022.13870. BD. The authors acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Beamtime was allocated for proposal I-20210986 EC. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. This activity has received funding from the European Institute of Innovation and Technology (EIT) Raw Materials through the project Smart WAAM: Microstructural Engineering and Integrated Non-Destructive Testing. YZ acknowledges the National Natural Science Foundation of China (51601091), the Natural Science Foundation of Jiangsu Province (BK 20160826), the Six Talent Peaks Project of Jiangsu Province (2017-XCL-051), the Fundamental Research Funds for the Central Universities (30917011106), and Key Research and Development Plan of Jiangsu Province (BE 2020085). Publisher Copyright: © 2023 The Author(s)The study reports that the combined use of in situ interlayer hot forging and post-deposition heat treatment (PDHT) could alter the typical coarse and oriented microstructure of the Ni-based superalloy 625 obtained by arc plasma directed energy deposition (DED) to a fine and non-oriented condition. In situ synchrotron X-ray diffraction and electron backscatter diffraction showed that the high-temperature (1100 °C/ 1 h) PDHT induced significant recrystallization, leading to grain refinement and low texture index, while partially dissolving deleterious Laves and δ phases. Low-temperature (980 °C/ 1 h) PDHT had a limited effect on the grain size refinement and induced the formation of secondary phases. It is shown that conventional heat treatments applied to Ni-based superalloy 625 obtained by arc plasma DED are not conducive to optimized microstructure features. In situ hot forging induced enough crystal defects to promote static recrystallization during PDHT. Besides, high-temperature PDHT met the AMS 5662 grain size requirements.publishersversionpublishe
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