Charge ordering and dielectric properties in the near half-doped Pr0.79Na0.21MnO3 perovskite

[Abstract] The Pr0.79Na0.21MnO3 perovskite has been prepared in polycrystalline form by a ceramic method. We have carried out its structural characterization by synchrotron X-ray powder diffraction (SXRPD) at room temperature and at 150 K (T<TCO). In the charge ordering (CO) state, the SXRPD data can be refined both on the basis of the site-centred model and the bond-centred model proposed for half-doped manganites, without a clear advantage of one model over the other. From the dielectric point of view, at the CO temperature this manganite shows a maximum in the dielectric constant whose origin is intrinsic, and cannot be attributed to the presence of extrinsic factors. We relate this dielectric behaviour to the formation of polar entities at the temperature of charge condensation, due to an asymmetric charge distribution intermediate between site-centred and bond-centred type.Xunta de Galicia; PGIDIT06PXB103298PRMinisterio de Educación y Ciencia; Project FEDER MAT 2004-0513

Utilización de la densidad de incidencia, en la valoración de faciores de riesgo de la infección nosocomial

ResumenEn la literatura se han propuesto las medidas de densidad de incidencia para la valoración de la infección nosocomial. A través de una cohorte retrospectiva de 843 pacientes se realiza una comparación entre la razón de densidades de incidencia (RDI) y el cociente de incidencias acumuladas o riesgo relativo (RR) en la cuantificación de factores de riesgo de la infección hospitalaria. Las variables que se analizaron fueron la intervención quirúrgica, su duración, el tipo de cirugía, la gravedad de la enfermedad subyacente y la edad. En todas las situaciones la RDI fue inferior al RR, al eliminar la prolongación de estancia producida por los distintos factores de riesgo. Ejemplos de ello fueron el que la RDI para la operación fue de 2,78, mientras que el RR ofreció valores de 6,46, o en la edad, donde los mayores de 60 años presentaron un RR significativo de 1,67, mientras que la RDI fue de 0,96. Esto sugiere que el empleo de la RDI facilitaría la comparabilidad de los resultados entre diferentes centros en la cuantificación de factores de riesgo para la infección nosocomial, aparte de cuantificar con más exactitud los distintos factores de riesgo, lo que tiene importancia a la hora de establecer las medidas de control.SummarySeveral authors have suggested that incidence density should be used in studying nosocomial infection. We assess several risk factors for hospital infection by two ratios, the incidence density ratio (IDR) and the relative risk (RR), in an historical cohort of 843 patients. The variables analyzed were: operation, its length, type of surgical wound, severity of underlying disease, and age. The IDR figures were always lower than those yielded by the RR. For example, the IDR for operated patients was 2.78, whereas RR yielded a figure of 6.46, or the IDR for patients >60 years old was 0.96, whereas the RR achieved a significant value of 1.67. This suggests that the use of IDR lo analyze risk factors for nosocomial infection improves comparability of results obtained in different hospital settings. Also, it may allow a more exact quantification of an effect. These facts influence implementation of nosocomial infection control measures

Exploiting the potential of bioactive molecules extracted by ultrasounds from avocado peelsfood and nutraceutical applications

Natural bioactive compounds from food waste have fomented interest in food and pharmaceutical industries for the past decade. In this work, it purposed the recovery of bioactive avocado peel extract using an environmentally friendly technique: the ultrasound assisted extraction. The response surface methodology was applied in order to optimize the conditions of the extraction, ethanol-water mixtures and time. The optimized extracts (ethanol 38.46%, 44.06 min, and 50 °C) were chemically characterized by HPLC-ESI-MS and FTIR. Its antioxidant ability, as well as, its effect on cell metabolic activity of normal (L929) and cancer (Caco-2, A549 and HeLa) cell lines were assessed. Aqueous ethanol extracts presented a high content in bioactive compounds with high antioxidant potential. The most representative class of the phenolic compounds found in the avocado peel extract were phenolic acids, such as hydroxybenzoic and hydroxycinnamic acids. Another important chemical group detected were the flavonoids, such as flavanols, flavanonols, flavones, flavanones and chalcone, phenylethanoids and lignans. In terms of its influence on the metabolic activity of normal and cancer cell lines, the extract does not significantly affect normal cells. On the other hand, it can negatively affect cancer cells, particularly HeLa cells. These results clearly demonstrated that ultrasound is a sustainable extraction technique, resulting in extracts with low toxicity in normal cells and with potential application in food, pharmaceutical or nutraceutical sectors.The authors acknowledge the financial support received from “Xunta de Galicia” (GRC ED431C 2017/62-GRC, and Project ED431F 2020/03). These projects are partially funded by the FEDER Program of the European Union (“Unha maneira de facer Europa”). This research was also funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit. Beatriz Gullón would like to express her gratitude to the Spanish Ministry of Economy and Competitiveness for her postdoctoral grant (Reference RYC2018-026177-I).info:eu-repo/semantics/publishedVersio

Characterization of a clinical olfactory test with an artificial nose

Clinical olfactory tests are used to address hyposmia/anosmia levels in patients with different types of olfactory impairments. Typically, a given test is employed clinically and then replaced by a new one after a certain period of use which can range from days to several months. There is a need to assess control quality of these tests and also for a procedure to quantify their degradation over time. In this paper we propose a protocol to employ low-cost artificial noses for the quantitative characterization of olfactory tests used in clinical studies. In particular, we discuss a preliminary study on the Connecticut Chemosensorial Clinical Research Center Test kit which shows that some odorants, as sensed by an artificial nose, seem to degrade while others are potentiated as the test ages. We also discuss the need to establish a map of correspondence between human and machine olfaction when artificial noses are used to characterize or compare human smell performance in research and clinical studies

Optimization of ultrasound-assisted extraction of phenolic compoundsfrom avocado peels

Avocado (Persea americana Mill.), a fruit native to Central America and Mexico, is one of the most consumed fruits in the world, with a global production of approximately 6.3 million tonnes in 2018. Its industrial processing generates significant amounts of by-products, mainly peels, seeds, or exhausted pulp, which disposal causes important environmental and economic problems. Nevertheless, these by-products present a high content of bioactive molecules with many human health benefits, which could be used for the formulation of functional foods or cosmetic products (Del Castillo-Llamosas et al., 2021; Rodríguez-Martínez et al., 2021). One of the important challenges for the recovery of added-value molecules from agro-industrial wastes is the selection of extraction technologies leading to high extraction efficiency and helping to preserve the quality of the recovered molecules. In this framework, ultrasound-assisted extraction (UAE) has been considered a green technology for the isolation of bioactive compounds from several natural sources. The purpose of the present study was to optimize the extraction of antioxidants from avocado peel (AP) using ultrasounds. The influence of ethanol/water ratio and time was evaluated using response Surface methodology (RSM). Under selected operational conditions (38.46% ethanol and 44.06 min), the response values were 45.34 mg GAE/g dried AP and 87.56 mg RE/g dried AP for TPC and TFC, respectively, with antioxidant levels of 73.25, 160.34 and 44.65 mg TE/g dried AP as determined by the DPPH, ABTS and FRAP methods, respectively. In addition, the optimized extracts were chemically characterized by HPLC-ESI-MS and FTIR. The main the phenolic compounds found in the avocado peel extract were phenolic acids, such as hydroxybenzoic and hydroxycinnamic acids.The authors acknowledge the financial support received from “Xunta de Galicia” (GRC ED431C 2017/62-GRC, and Project ED431F 2020/03). These projects are partially funded by the FEDER Program of the European Union (“Unha maneira de facer Europa”). Beatriz Gullón would like to express her gratitude to the Spanish Ministry of Economy and Competitiveness for her postdoctoral grant (Reference RYC2018-026177-I).info:eu-repo/semantics/publishedVersio

Multiferroic behavior in the new double-perovskite Lu2_2MnCoO6_6

We present a new member of the multiferroic oxides, Lu$_2$MnCoO$_6$, which we have investigated using X-ray diffraction, neutron diffraction, specific heat, magnetization, electric polarization, and dielectric constant measurements. This material possesses an electric polarization strongly coupled to a net magnetization below 35 K, despite the antiferromagnetic ordering of the $S = 3/2$ Mn$^{4+}$ and Co$^{2+}$ spins in an $\uparrow \uparrow \downarrow \downarrow$ configuration along the c-direction. We discuss the magnetic order in terms of a condensation of domain boundaries between $\uparrow \uparrow$ and $\downarrow \downarrow$ ferromagnetic domains, with each domain boundary producing a net electric polarization due to spatial inversion symmetry breaking. In an applied magnetic field the domain boundaries slide, controlling the size of the net magnetization, electric polarization, and magnetoelectric coupling

About the origin of the Mediterranean Waters warming during the twentieth century

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Genome-Wide Association Analysis for Resistance to Infectious Pancreatic Necrosis Virus Identifies Candidate Genes Involved in Viral Replication and Immune Response in Rainbow Trout (Oncorhynchus mykiss)

Infectious pancreatic necrosis (IPN) is a viral disease with considerable negative impact on the rainbow trout (Oncorhynchus mykiss) aquaculture industry. The aim of the present work was to detect genomic regions that explain resistance to infectious pancreatic necrosis virus (IPNV) in rainbow trout. A total of 2,278 fish from 58 full-sib families were challenged with IPNV and 768 individuals were genotyped (488 resistant and 280 susceptible), using a 57K SNP panel Axiom, Affymetrix. A genome-wide association study (GWAS) was performed using the phenotypes time to death (TD) and binary survival (BS), along with the genotypes of the challenged fish using a Bayesian model (Bayes C). Heritabilities for resistance to IPNV estimated using genomic information, were 0.53 and 0.82 for TD and BS, respectively. The Bayesian GWAS detected a SNP located on chromosome 5 explaining 19% of the genetic variance for TD. The proximity of Sentrin-specific protease 5 (SENP5) to this SNP makes it a candidate gene for resistance against IPNV. In case of BS, a SNP located on chromosome 23 was detected explaining 9% of the genetic variance. However, the moderate-low proportion of variance explained by the detected marker leads to the conclusion that the incorporation of all genomic information, through genomic selection, would be the most appropriate approach to accelerate genetic progress for the improvement of resistance against IPNV in rainbow trout