878 research outputs found

    Multiferroic behavior in the new double-perovskite Lu2_2MnCoO6_6

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    We present a new member of the multiferroic oxides, Lu2_2MnCoO6_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=3/2S = 3/2 Mn4+^{4+} and Co2+^{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

    A Cremophor-Free Formulation for Tanespimycin (17-AAG) using PEO-b-PDLLA Micelles: Characterization and Pharmacokinetics in Rats

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    Tanespimycin (17-allylamino-17-demethoxygeldanamycin or 17-AAG) is a promising heat shock protein 90 inhibitor currently undergoing clinical trials for the treatment of cancer. Despite its selective mechanism of action on cancer cells, 17-AAG faces challenging issues due to its poor aqueous solubility, requiring formulation with Cremophor EL (CrEL) or ethanol (EtOH). Therefore, a CrEL-free formulation of 17-AAG was prepared using amphiphilic diblock micelles of poly(ethylene oxide)-b-poly(D,L-lactide) (PEO-b-PDLLA). Dynamic light scattering revealed PEO-b-PDLLA (12:6 kDa) micelles with average sizes of 257 nm and critical micelle concentrations of 350 nM, solubilizing up to 1.5 mg/mL of 17-AAG. The area under the curve (AUC) of PEO-b-PDLLA micelles was 1.3-fold that of the standard formulation. The renal clearance (CLrenal) increased and the hepatic clearance (CLhepatic) decreased with the micelle formulation, as compared to the standard vehicle. The micellar formulation showed a 1.3-fold increase in the half-life (t1/2) of the drug in serum and 1.2-fold increase in t1/2 of urine. As expected, because it circulated longer in the blood, we also observed a 1.7-fold increase in the volume of distribution (Vd) with this micelle formulation compared to the standard formulation. Overall, the new formulation of 17-AAG in PEO-b-PDLLA (12:6 kDa) micelles resulted in a favorable 150-fold increase in solubility over 17-AAG alone, while retaining similar properties to the standard formulation. Our data indicates that the nanocarrier system can retain the pharmacokinetic disposition of 17-AAG without the need for toxic agents such as CrEL and EtOH

    Preliminary study on the use of the 137 Cs method for soil erosion investigation in the pampean region of Argentina

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    Soil erosion is the most important degradation process in A rgentine. According to the estimation of 4.9 millon ha in Pampa Ondulada Region, 1.600.000 ha (36% of agricultural soils) are affected by the erosion. Field measurements of soil erosion and sediment deposition using classical techniques are difficult, time consuming, and expensive but indispensable to feed the prediction models for conservation practices design and fa rm planning. Many authors have reported that the measurement of fallout nuclides is useful tool to characterize geomorphical processes. Walling and He proposes models for conve rting 137Cs depletion/enrichment amounts to net soil loss/deposition. These models are based in the comparison between a reference 137Cs profile in a long term undisturbed site (control site) and the 137Cs profiles in the suspected eroded or deposited sites in the landscape. The aim of this study is to provide a complete and well representative set of data on the erosion intensity in topographical conditions for the Pampa Ondulada Region in A rgentine by using a tracer technique. The study area is a small watershed (about 300 ha), located in Arroyo del Tala medium basin, within Partido of San Pedro in Buenos Aires Province, Argentine. This paper presents a group of results from a detailed investigation of erosion and sediment delivery, within a 49 ha cultivated field study site in this watershed. The base of sampling strategy is the grid approach. A reference inventory, representing the local fallout input, was searched for at a site experiencing neither erosion nor deposition. Radiocaesium analyses were made at the Nuclear Regulatory Authority Laboratory by a GE Hp detector. To make an interpretation of 137Cs distribution of soil losses and sedimentation, the Mass Balance Model 2 was used (Walling and He 1997). The erosion/deposition rates from Mass Balance Model 2 are in the range of 0 to -30 t·ha-1·y-1 for erosion, and 0 to 19 t·ha-1·y-1 for deposition, and these values matched well, with the rates of erosion obtained by classical methods. The 137Cs spatial and depth distribution are showed in a map, and enabled to study the relationship of the erosion to the topography, and a good discrimination in subclasses within moderate erosion class and sedimentation class

    Potential of genomic technologies to improve disease resistance in molluscan aquaculture

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    Molluscan aquaculture is a major contributor to global seafood production, but is hampered by infectious disease outbreaks that can cause serious economic losses. Selective breeding has been widely used to improve disease resistance in major agricultural and aquaculture species, and has clear potential in molluscs, albeit its commercial application remains at a formative stage. Advances in genomic technologies, especially the development of cost-efficient genomic selection, have the potential to accelerate genetic improvement. However, tailored approaches are required owing to the distinctive reproductive and life cycle characteristics of molluscan species. Transgenesis and genome editing, in particular CRISPR/Cas systems, have been successfully trialled in molluscs and may further understanding and improvement of genetic resistance to disease through targeted changes to the host genome. Whole-organism genome editing is achievable on a much greater scale compared to other farmed species, making genome-wide CRISPR screening approaches plausible. This review discusses the current state and future potential of selective breeding, genomic tools and genome editing approaches to understand and improve host resistance to infectious disease in molluscs. This article is part of the Theo Murphy meeting issue ‘Molluscan genomics: broad insights and future directions for a neglected phylum’

    Atmospheric mixing ratios of methyl ethyl ketone (2-butanone) in tropical, boreal, temperate and marine environments

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    Methyl ethyl ketone (MEK) enters the atmosphere following direct emission from vegetation and anthropogenic activities, as well as being produced by the gas-phase oxidation of volatile organic compounds (VOCs) such as n-butane. This study presents the first overview of ambient MEK measurements at six different locations, characteristic of forested, urban and marine environments. In order to understand better the occurrence and behaviour of MEK in the atmosphere, we analyse diel cycles of MEK mixing ratios, vertical profiles, ecosystem flux data, and HYSPLIT back trajectories, and compare with co-measured VOCs. MEK measurements were primarily conducted with proton-transfer-reaction mass spectrometer (PTR-MS) instruments. Results from the sites under biogenic influence demonstrate that vegetation is an important source of MEK. The diel cycle of MEK follows that of ambient temperature and the forest structure plays an important role in air mixing. At such sites, a high correlation of MEK with acetone was observed (e.g. r2 = 0.96 for the SMEAR Estonia site in a remote hemiboreal forest in Tartumaa, Estonia, and r2 = 0.89 at the ATTO pristine tropical rainforest site in central Amazonia). Under polluted conditions, we observed strongly enhanced MEK mixing ratios. Overall, the MEK mixing ratios and flux data presented here indicate that both biogenic and anthropogenic sources contribute to its occurrence in the global atmosphere

    Ensayos de dinteles de fábrica de ladrillo atirantada sobre los nuevos Apoyos Pi, distanciados 6m entre sí

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    Comunicación presentada en las II Jornadas de Investigación en Construcción: "60 años de Informes de la Construcción", celebradas los pasados 22, 23 y 24 de mayo de 2008 en el Instituto "Eduardo Torroja" de Ciencias de la Construcción (IETCC-CSIC) de Madrid.Comparando la Arquitectura de Ladrillos del s.XIX con el empleo del ladrillo en la Arquitectura del s.XX, se puede observar que abunda mayor patología en las fábricas de ladrillo cara vista recientes que en las más antiguas. El primer paso para prevenir la abundante fisuración de la albañilería apreciada en España a finales del siglo pasado, se dio en 1992, con la realización del "Manual Murfor: La fábrica armada", estableciéndose en él los criterios posteriormente contemplados en el "Eurocódigo 6: Estructuras de Fábrica", de recomendar armar con el 0,03% de la sección del muro, y a distancias verticales no mayores de 600mm. Las primeras aplicaciones arquitectónicas de la fábrica armada en España, fueron realizadas por este Arquitecto en sus obras de la Plaza de la Remonta y de El Espinillo, divulgándose por su potencial arquitectónico, tanto en Europa como en América.En este artículo se retoman las posibilidades del incremento de prestaciones de la fábrica armada Murfor con "arcos atirantados ciegos de gran luz", establecidas por primera vez en el Manual español, lo que permite salvar 6m de luz con solamente 2 armaduras Murfor de 5mm de diámetro en la parte inferior de los dinteles.Los autores agradecen la inestimable colaboración de los Institutos de Investigación IBAC de Aachen (Alemania) y el I.E. Torroja de Madrid (España), por haber hecho posible esta interesante colaboración investigadora europea de valor internacional.Peer reviewe

    Customized Smart Andon System to Improve the Efficiency of Industrial Departments

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    35-37A customized industrial system to realize the supporting requests in manufacturing lines with detailed statistical information is presented. Also called customized smart Andon system. The system is based on a software and hardware design customized for particular industry needs according to the internal organizational structure. The results of the projection are that Andon system permits an important reduction of the time required for attending and finishing whatever problem in the manufacturing line

    Efficient Expression of <i style="box-sizing: border-box;">Igf-1</i> from Lentiviral Vectors Protects <i style="box-sizing: border-box;">In Vitro</i> but Does Not Mediate Behavioral Recovery of a Parkinsonian Lesion in Rats

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    Gene therapy approaches delivering neurotrophic factors have offered promising results in both preclinical and clinical trials of Parkinson's disease (PD). However, failure of glial cell line-derived neurotrophic factor in phase 2 clinical trials has sparked a search for other trophic factors that may retain efficacy in the clinic. Direct protein injections of one such factor, insulin-like growth factor (IGF)-1, in a rodent model of PD has demonstrated impressive protection of dopaminergic neurons against 6-hydroxydopamine (6-OHDA) toxicity. However, protein infusion is associated with surgical risks, pump failure, and significant costs. We therefore used lentiviral vectors to deliver Igf-1, with a particular focus on the novel integration-deficient lentiviral vectors (IDLVs). A neuron-specific promoter, from the human synapsin 1 gene, excellent for gene expression from IDLVs, was additionally used to enhance Igf-1 expression. An investigation of neurotrophic effects on primary rat neuronal cultures demonstrated that neurons transduced with IDLV-Igf-1 vectors had complete protection on withdrawal of exogenous trophic support. Striatal transduction of such vectors into 6-OHDA-lesioned rats, however, provided neither protection of dopaminergic substantia nigra neurons nor improvement of animal behavior

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

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    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
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