3,427 research outputs found
Short-range charge-order in NiO perovskites (=Pr,Nd,Eu) probed by X-ray absorption spectroscopy
The short-range organization around Ni atoms in orthorhombic NiO
(=Pr,Nd,Eu) perovskites has been studied over a wide temperature range by Ni
K-edge x-ray absorption spectroscopy. Our results demonstrate that two
different Ni sites, with different average Ni-O bond lengths, coexist in those
orthorhombic compounds and that important modifications in the Ni nearest
neighbors environment take place across the metal-insulator transition. We
report evidences for the existence of short-range charge-order in the
insulating state, as found in the monoclinic compounds. Moreover, our results
suggest that the two different Ni sites coexists even in the metallic state.
The coexistence of two different Ni sites, independently on the ion,
provides a common ground to describe these compounds and shed new light in the
understanding of the phonon-assisted conduction mechanism and unusual
antiferromagnetism present in all NiO compounds.Comment: 4 pages, 3 figures, accepted PRB - Brief Report Dec.200
Release of polyphenols from starch-chitosan based films containing thyme extract
[EN] The release kinetics of thyme extract polyphenols (TE) from chitosan (CH), pea starch (S) and CH:S blend films in different solvents was evaluated, as well as their antioxidant activity in each release media. Pure starch films showed the fastest delivery rate and the highest delivery ratio of polyphenols, although the corresponding release media exhibited the lowest antioxidant capacity. TE provided CH based films with remarkable antioxidant activity, despite the lower polyphenol release obtained in all solvents, due to the strong polyphenols-chitosan interactions. The maximum amount of polyphenols delivered was found in the acetic acid solution, due to the high solubility of CH. The incorporation of tannic acid (TA) into CH films promoted cross-linking effect, which delays the TE release rate in water and ethanol aqueous solutions, except for CH:S:TA films. Thus, the polarity of the solvents and the polyphenols-matrix interactions markedly affected the polyphenol release and the antioxidant activity of the films.The authors acknowledge the financial support provided by the Spanish Ministerio de Economía y Competividad (Projects AGL2013-42989-R and AGL2016-76699-R). Author Emma Talón thanks Universitat Politècnica València for a FPI Grant (99/2011).Talón-Argente, E.; Trifkovic, KT.; Vargas, M.; Chiralt, A.; González Martínez, MC. (2017). Release of polyphenols from starch-chitosan based films containing thyme extract. Carbohydrate Polymers. 175:122-130. https://doi.org/10.1016/j.carbpol.2017.07.067S12213017
Magneto-Fluorescent Mesoporous Nanocarriers for the Dual-Delivery of Ofloxacin and Doxorubicin to Tackle Opportunistic Bacterial Infections in Colorectal Cancer
Funding Information: This work was funded by the Associate Laboratory for Green Chemistry—LAQV which is financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020) as well as the Scientific Society PROTEOMASS (Portugal) for funding support (General Funding Grant 2021). G.M thanks to FCT/MEC (Portugal) for his doctoral grant PD/BD/142865/2018. E.O thanks FCT/MEC (Portugal) for the individual contract, CEECIND/00648/2017. This work was also funded by FCT—Foundation for Science and Technology, I.P., through projects UIDB/04077/2020, UIDP/04077/2020, OrMagNa—PTDC/NAN-MAT/28785/2017, BioISI—UID/Multi/04046/2019, UIDB/04046/2020 and UIDP/04046/2020 Centre grants (BioISI) and NECL infrastructure. Publisher Copyright: © 2022 by the authors.Cancer-related opportunistic bacterial infections are one major barrier for successful clinical therapies, often correlated to the production of genotoxic factors and higher cancer incidence. Although dual anticancer and antimicrobial therapies are a growing therapeutic fashion, they still fall short when it comes to specific delivery and local action in in vivo systems. Nanoparticles are seen as potential therapeutic vectors, be it by means of their intrinsic antibacterial properties and effective delivery capacity, or by means of their repeatedly reported modulation and maneuverability. Herein we report on the production of a biocompatible, antimicrobial magneto-fluorescent nanosystem (NANO3) for the delivery of a dual doxorubicin–ofloxacin formulation against cancer-related bacterial infections. The drug delivery capacity, rendered by its mesoporous silica matrix, is confirmed by the high loading capacity and stimuli-driven release of both drugs, with preference for tumor-like acidic media. The pH-dependent emission of its surface fluorescent SiQDs, provides an insight into NANO3 surface behavior and pore availability, with the SiQDs working as pore gates. Hyperthermia induces heat generation to febrile temperatures, doubling drug release. NANO3-loaded systems demonstrate significant antimicrobial activity, specifically after the application of hyperthermia conditions. NANO3 structure and antimicrobial properties confirm their potential use in a future dual anticancer and antimicrobial therapeutical vector, due to their drug loading capacity and their surface availability for further modification with bioactive, targeting species.publishersversionpublishe
Physical and chemical nature of the scaling relations between adsorption energies of atoms on metal surfaces
Umbrales económicos para la araña roja Tetranychus urticae (acari: Tetranychidae) en mandarino
Tetranychus urticae es una plaga clave en cítricos, especialmente en mandarina clementina. Se evaluó el daño de este ácaro sobre la producción de 24 árboles de clementino durante tres años consecutivos. Los árboles fueron visitados semanalmente, y se estimó tanto la población de araña roja como la de ácaros fitoseidos, así como la brotación. Al final de cada temporada, se recolectaron las clementinas, se pesaron, y se evaluó el daño ocasionado por T. urticae en fruto. Se encontró una relación negativa entre la densidad de la araña roja y el rendimiento (kg/árbol). Sin embargo, las correlaciones entre el daño en fruto y los diferentes estimadores de araña roja fueron más fuertes. Las regresiones multivariantes destacaron el papel clave que juegan tanto los ácaros fitoseidos como la brotación, que se correlacionaron negativamente con el daño en fruto. El período más corto de muestreo que predijo satisfactoriamente el daño en fruto en la recolección, se extendió desde el 1 agosto hasta mediados de octubre. A efectos de Gestión Integrada de Plagas, se estimó un umbral económico de daños de 31,14 hembras adultas de araña roja en hoja sintomática por m2. Teniendo en cuenta la dinámica poblacional de T. urticae, el umbral de intervención varió de 10 a 15 hembras adultas de araña roja en hoja sintomática por m2 . Cuando se supera este umbral, los agricultores tendrían una ventana de una semana para aplicar cualquiera de las medidas (biológicas o químicas) que disponen contra T. urticae.Este trabajo fue parcialmente finan- ciado por el Ministerio de Ciencia e Innovación (proyectos AGL2011- 30538-C03-01-07464 AGL2004-C03- 01, AGL2005-07155-C03, y AGL2008- 05287-C04-03/AGR). S.P.R. y E.A.F. fueron beneficiarias de una beca pre- doctoral del MICINN y de la UJI, respectivamente
Mediterranean Landscape Re-Greening at the Expense of South American Agricultural Expansion
The stabling of livestock farming implies changes in both local ecosystems (regeneration of forest stands via reduced grazing) and those located thousands of kilometers away (deforestation to produce grain for feeding livestock). Despite their importance, these externalities are poorly known. Here we evaluated how the intensification and confinement of livestock in Spain has affected forest surface changes there and in South America, the largest provider of soybeans for animal feed to the European Union. For this purpose, we have used Spanish soybean import data from Brazil, Paraguay and Argentina and a land condition map of Spain. The area of secondary forest in Spain that has regenerated as a result of livestock stabling has been ~7000 kha for the decade 2000–2010. In the same period, 1220 kha of high value South American ecosystems (e.g. Chaco dry Forest, Amazonian rainforest or Cerrado) have been deforested. While these figures may offer a favorable interpretation of the current industrial livestock production, it is not possible to speak of compensation when comparing the destruction of well-structured ecosystems, such as primary South American forests, with the creation of secondary forest landscapes in Spain, which are also prone to wildfires. Our results highlight how evaluating land use change policies at a national or regional level is an incomplete exercise in our highly telecoupled and globalized world.This study was funded by the European Research Council grant agreement nº 647038 (BIODESERT). FTM acknowledges support from Generalitat Valenciana (CIDEGENT/2018/041)
Effects of ezetimibe on cholesterol metabolism in HIV-infected patients with protease inhibitor-associated dyslipidemia: a single-arm intervention trial
BACKGROUND: The effects of ezetimibe on cholesterol metabolism in HIV-infected patients receiving boosted protease inhibitors have not been thoroughly assessed. The aim of this study was to assess cholesterol homeostasis in patients with PI associated dyslipidemia and its relationship with the response to treatment with the cholesterol-absorption inhibitor ezetimibe. METHODS: Fifteen patients with ritonavir-boosted PI-containig therapy and LDL-cholesterol > 3.36 mmol/L (>130 mg/dL) were assessed at baseline and after an 8-week course of ezetimibe 10 mg/d. Serum non-cholesterol sterols were measured at each visit as markers of cholesterol synthesis and absorption. Total-, LDL-, and HDL-cholesterol triglycerides, apolipoproteins A1 and B, high sensitivity C-reactive protein, CD4 cells and HIV-1 RNA were also measured. RESULTS: Ezetimibe treatment was well tolerated in all patients and resulted in significant reductions in total cholesterol (-11.4%, p = .002), LDL-cholesterol (-20.4%, p = .003), non-HDL-cholesterol (-13.4%, p = .002) and apolipoprotein B (-9.1%, p = .021). Treatment with ezetimibe was associated with decreased cholesterol absorption markers (campesterol-to-cholesterol ratio -43.0%, p = .001; sitosterol-to-cholesterol ratio -41.9%, p = .001) and increased synthesis markers (lathosterol-to-cholesterol ratio 53.2%, p = .005). Baseline absorption or synthesis markers were unrelated to the response to treatment. CD4 cell count and plasma HIV-1 RNA remained unchanged. CONCLUSIONS: The level of cholesterol absorption or synthesis does not appear to be a major determinant of the responsiveness to ezetimibe in patients on ritonavir-boosted PI-containing therapy
A Conserved GPG-Motif in the HIV-1 Nef Core Is required for principal nef-activities
© 2015 Martínez-Bonet et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedTo find out new determinants required for Nef activity we performed a functional alanine scanning analysis along a discrete but highly conserved region at the core of HIV-1 Nef. We identified the GPG-motif, located at the 121–137 region of HIV-1 NL4.3 Nef, as a novel protein signature strictly required for the p56Lck dependent Nef-induced CD4-downregulation in T-cells. Since the Nef-GPG motif was dispensable for CD4-downregulation in HeLa-CD4 cells, Nef/AP-1 interaction and Nef-dependent effects on Tf-R trafficking, the observed effects on CD4 downregulation cannot be attributed to structure constraints or to alterations on general protein trafficking. Besides, we found that the GPG-motif was also required for Nef-dependent inhibition of ring actin re-organization upon TCR triggering and MHCI downregulation, suggesting that the GPG-motif could actively cooperate with the Nef PxxP motif for these HIV-1 Nef-related effects. Finally, we observed that the Nef-GPG motif was required for optimal infectivity of those viruses produced in T-cells. According to these findings, we propose the conserved GPG-motif in HIV-1 Nef as functional region required for HIV-1 infectivity and therefore with a potential interest for the interference of Nef activity during HIV-1 infection.This work was supported by the Ramon y Cajal research program (MICIIN-RYC-2005-002174; http://www.mineco.gob.es/portal/site/mineco/idi), Fondo de Investigación Sanitaria en España (FIS-PS09/01386; http://www.isciii.es/) to RM, and Comunidad de Madrid (S-2010/BMD-2332; http://www.madrimasd.org/) to MAM-F, and the Deutsche Forschungsgemeinschaft (TRR83, project 15 to OTF). MM-B, CP and VB hold a fellowship from the Fondo de Investigación Sanitaria en España (FIS, http://www.isciii.es/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio
A Conserved GPG-Motif in the HIV-1 Nef Core Is Required for Principal Nef-Activities.
To find out new determinants required for Nef activity we performed a functional alanine scanning analysis along a discrete but highly conserved region at the core of HIV-1 Nef. We identified the GPG-motif, located at the 121-137 region of HIV-1 NL4.3 Nef, as a novel protein signature strictly required for the p56Lck dependent Nef-induced CD4-downregulation in T-cells. Since the Nef-GPG motif was dispensable for CD4-downregulation in HeLa-CD4 cells, Nef/AP-1 interaction and Nef-dependent effects on Tf-R trafficking, the observed effects on CD4 downregulation cannot be attributed to structure constraints or to alterations on general protein trafficking. Besides, we found that the GPG-motif was also required for Nef-dependent inhibition of ring actin re-organization upon TCR triggering and MHCI downregulation, suggesting that the GPG-motif could actively cooperate with the Nef PxxP motif for these HIV-1 Nef-related effects. Finally, we observed that the Nef-GPG motif was required for optimal infectivity of those viruses produced in T-cells. According to these findings, we propose the conserved GPG-motif in HIV-1 Nef as functional region required for HIV-1 infectivity and therefore with a potential interest for the interference of Nef activity during HIV-1 infection.This work was supported by the Ramon y Cajal research program (MICIIN-RYC-2005-002174; http://www.mineco.gob.es/portal/site/mineco/idi), Fondo de Investigación Sanitaria en España (FIS-PS09/01386; http://www.isciii.es/) to RM, and Comunidad de Madrid (S-2010/BMD-2332; http://www.madrimasd.org/) to MAM-F, and the Deutsche Forschungsgemeinschaft (TRR83, project 15 to OTF). MM-B, CP and VB hold a fellowship from the Fondo de Investigación Sanitaria en España (FIS, http://www.isciii.es/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S
Relación entre las variables asociadas al trauma (disociación, culpa, evitación experiencial y síntomas de estrés postraumático) y su influencia en la salud percibida.
Introducción: Una experiencia traumática se define como un evento que supera la capacidad de una persona para responder a él. El trauma se ha asociado con una variedad de problemas psicológicos, entre los que destacan los síntomas de estrés postraumático, problemas de salud y una falta de bienestar percibido. Además, varios estudios han demostrado que otras variables están asociadas con la exposición al trauma y pueden tener un papel importante para explicar el desarrollo y el mantenimiento de los síntomas postraumáticos. Estas son: disociación, culpa y evitación experiencial. Conjuntamente, se han establecido diferencias de género en cada una de ellas. Sin embargo, no existen estudios que hayan considerado todas estas variables simultáneamente.
Objetivos: Examinar la relación entre disociación, culpa, evitación experiencial y síntomas de estrés postraumático en un grupo de personas con historia de trauma y su influencia sobre su salud percibida. Además, comprobar si tales relaciones se modifican a través del género.
Método: Se incluyó a un total de 903 participantes. La edad media fue de 22.25 (DT= 5.17) para la muestra total, 21.9 (DT= 4.5) para la muestra de la mujer y de 23.50 (DT= 6.92) para la muestra de los hombres. Se empleó un modelo de ecuaciones estructurales para poner a prueba las relaciones postuladas en el modelo hipotético, y se analizó este a través de un análisis multi-grupo (hombres y mujeres).
Resultados: Los resultados dieron apoyo empírico al modelo hipotético, mostrando relaciones significativas entre las variables en ambos sexos. Sólo en los hombres, la asociación entre evitación experiencial y los síntomas postraumáticos no es significativa, pero el modelo final es significativamente equivalente entre género.
Conclusiones: En conjunto, estos hallazgos arrojan luz sobre los factores que deben ser considerados cuando se desarrollan estrategias tanto preventivas como de tratamiento de personas que han vivido algún tipo de trauma.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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