1,040 research outputs found

    Fourier-space generalized magneto-optical ellipsometry

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    The magneto-optical Kerr effect (MOKE) is widely exploited in laboratory-based setups for the study of thin films and nanostructures, providing magnetic characterization with good spatial and temporal resolutions. Due to the complex coupling of light with a magnetic sample, conventional MOKE magnetometers normally work by selecting a small range of incident wave-vector values, focusing the incident light beam to a small spot, and recording the reflected intensity at that angular range by means of photodetectors. Using this approach, additional methodologies and measurements are required for full vectorial magnetic characterization. Here, we computationally investigate a Fourier-space MOKE setup, where a focused beam ellipsometer using high numerical aperture optics and a camera detector is employed to simultaneously map the intensity distribution for a wide range of incident and reflected wave vectors. We employ circularly incident polarized light and no analyzing optics, in combination with a fitting procedure of the light intensity maps to the analytical expression of the Kerr effect under linear approximation. In this way, we are able to retrieve the three unknown components of the magnetization vector as well as the material' s optical and magneto-optical constants with high accuracy and short acquisition times, with the possibility of single-shot measurements. Fourier MOKE is thus proposed as a powerful method to perform generalized magneto-optical ellipsometry for a wide range of magnetic materials and devices

    Extraction and characterization of mucilage from Opuntia ficus-indica cultivated on hydroponic system

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    An interesting component of Opuntia ficus-indica is the mucilage for its properties and industrial uses. However, the great variability of its quantity and quality caused by different growing conditions, the hydroponic system is an alternative. The objective of the present study was cultivating 4 species of Mexican Nopal in a hydroponic system, extract and characterize the mucilage. The characterization consists of pH, ºBrix, colour, proximal analysis, phenols, antioxidant activity, crystallinity, and chemical bonding constituents. ‘Copena F1’ is the best alternative for production of biomass and mucilage. ‘Villanueva’ had high levels of phenols (1,311.83 mg GAE g-1), antioxidant capacity ABTS·+ (6,301.12 mg TE g-1) and FRAP (536.26 mg GAE g-1). A large amount of lipids (1.39%), and nitrogen-free extract (49.27%). The functional groups of the mucilage were identified (-OH, -CH, -CH2, -CH3, C=C, HCH, -CHO) and gypsum, cellulose, SiO2 CaSO4, C2H2K2O5, CaCO3 and CaH2 by X-ray diffraction. The hydroponic system is a viable alternative for production of nopal and mucilage of high-quality mucilage that can be used in several sectors of the industry

    Haloalkalitolerant Actinobacteria with capacity for anthracene degradation isolated from soils close to areas with oil activity in the State of Veracruz, Mexico

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    The use of native strains of microorganisms from soils is an excellent option for bioremediation. To our knowledge, until now there has been no other group working on the isolation of Actinobacteria from contaminated soils in Mexico. In this study, samples of soils close to areas with oil activity in the State of Veracruz, Mexico, were inoculated for the isolation of Actinobacteria. The strains isolated were characterized morphologically, and the concentrations of NaCl and pH were determined for optimal growth. Strain selection was performed by the detection of a phylogenetic marker for Actinobacteria located at the 23S rRNA gene, followed by species identification by sequencing the 16S rRNA gene. Several haloalkalitolerant Actinobacteria were isolated and identified as: Kocuria rosea, K. palustris, Microbacterium testaceum, Nocardia farcinica and Cellulomonas denverensis. Except for C. denverensis, the biomass of all strains increased in the presence of anthracene. The strains capacity to metabolize anthracene (at 48 h), determined by fluorescence emission, was in the range of 46–54%. During this time, dihydroxy aromatic compounds formed, characterized by attenuated total reflectance Fourier transform infrared spectroscopy bands of 1205 cm–1 and 1217 cm–1. Those Actinobacteria are potentially useful for the bioremediation of saline and alkaline environments contaminated with polycyclic aromatic hydrocarbon compounds. [Int Microbiol 2016; 19(1):15-26]Keywords: Kocuria · Microbacterium · haloalkalitolerant Actinobacteria · anthracene degradation · State of Veracruz, Mexic

    Detección y expresión de los receptores X retinoicos (RXR) en la mucosa yeyunal de crías de alpacas (Vicugna pacos)

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    The present study determined the presence of retinoic X receptor isoforms (RXR) genes in the genome of adult alpacas and their expression in the jejunal mucosa of alpaca offspring. Blood leukocyte samples from five adult alpacas were used to detect the genes of the RXRbeta and RXRgamma isoforms by PCR using specific primers, and to determine the expression of the RXR gene isoforms, 35 jejunum samples from young alpacas were used (1-50 days old), to which the real-time RT-PCR test was performed. The results indicate that the alpacas have encoded the RXRbeta and RXRgamma isoforms in their genome and that they have different levels of expression in the jejunal mucosa of baby alpacas. High expression of RXRgamma and RXRbeta was detected. These results indicate that the RXRgamma and RXRbeta receptors are being expressed in the mucosa of the jejunum of baby alpacas.El presente estudio determinó la presencia de los genes de las isoformas de los receptores X retinoicos (RXR) en el genoma de alpacas adultas y su expresión en la mucosa yeyunal de las crías de alpaca. Se utilizaron muestras de leucocitos sanguíneos de cinco alpacas adultas para detectar los genes de las isoformas RXRbeta y RXRgamma por PCR utilizando cebadores específicos, y para determinar la expresión de las isoformas de los genes RXR se utilizaron 35 muestras de yeyuno de crías de alpacas (1-50 días), a las cuales se les realizó la prueba de RT-PCR tiempo real. Los resultados indican que las alpacas tienen codificadas las isoformas de RXRbeta y RXRgamma en su genoma y que tienen distintos niveles de expresión en la mucosa yeyunal de las crías. Se detectó una alta expresión de RXRgamma y RXRbeta. Estos resultados indican que los receptores RXRgamma y RXRbeta se están expresando en la mucosa del yeyuno de crías de alpacas

    Caracterización físico-química y microbiológica del lactosuero del queso Paipa

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    El queso Paipa es el único queso madurado que se produce en Colombia; su lactosuero, al ser desechado de manera inadecuada, genera un problema ambiental, por lo que es necesario plantear opciones para industrializarlo y evitar así esta situación; adelantar su caracterización físico-química y microbiológica contribuye a este propósito. Se analizaron muestras de lactosuero de tres plantas representativas de queso Paipa; los promedios evaluados presentaron diferencias estadísticas significativas (P≤0,01) en los parámetros de calorías, carbohidratos, humedad, grasa, proteína, aerobios mesófilos, mohos, bacterias ácido lácticas (BAL) y levaduras. Los resultados promedios de las muestras analizadas tienen valores en el rango de clasificación como suero dulce, con un pH promedio de 5,7, y lactosa de 5,1 %; sin embargo, estos no presentaron buena calidad sanitaria. Las bondades del lactosuero del queso Paipa en su composición, en lo referente a los promedios en proteína (0,71 ± 0,12), cenizas (0,42), grasa (0,5 ± 0,14) y sus recuentos en levaduras en promedio de 38 x 102 y de BAL de 10,7 x 104, lo posicionan como alternativa para su uso como medio de cultivo y materia prima de procesos biotecnológicos en la elaboración de distintos productos en la industria alimentaria

    SEROPREVALENCIA DE ANTICUERPOS CONTRA SEROVARES DE Leptospira spp EN YEGUAS DE UN HARAS DE LA CIUDAD DE LIMA.

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    The seroprevalence of Leptospira spp in mares with abortion problems in a stud in Lima was determined. Two blood samples were collected from each mare within a 2-month period for the detection of antibodies against 12 Leptospira serovars using the microaglutination test. The serovars included in the study were icterohaemorraghiae, canicola, pomona, bratislava, georgia, tarassovi, autumnalis, pyrogenes, hardjo, ballum, australis and gryppotyphosa. Total prevalence of Leptospira spp was 96 and 100% in the first and second sampling respectively. Antibodies against serovars canicola, icterohaemorraghiae, pomona and georgia were more frequently detected during both period of sampling. No antibodies were found against serovars bratislava, tarassovi, autumnalis, hardjo, australis or gryppotyphosa. Sixty five percent of the animals were positive for three serovars simultaneously. The most frequent serovar was georgia (100%), which has not been reported as a pathogen for horses. The study showed the wide distribution of various Leptospira serovars in horses.Se determinó la prevalencia de Leptospira spp en yeguas de un haras de la ciudad de Lima con historial de aborto. Se tomaron 2 muestras de suero de todas las yeguas (n= 48) con un intervalo de 2 meses para la detección de anticuerpos contra 12 serovares de Leptospira mediante la prueba de microaglutinación. Los serovares fueron icterohaemorraghiae, canicola, pomona, bratislava, georgia, tarassovi, autumnalis, pyrogenes, hardjo, ballum, australis y gryppotyphosa. La prevalencia total de Leptospira spp fue de 96 y 100% en el primer y segundo muestreo, respectivamente. Anticuerpos contra los serovares canicola, icterohaemorraghiae, pomona y georgia fueron los más frecuentemente detectados durante los dos periodos de muestreos. No se encontró anticuerpos contra los serovares bratislava, tarassovi, autumnalis, hardjo, australis y gryppotyphosa. El 65% de los equinos fue positivo a anticuerpos contra tres serovares a la vez. El serovar de Leptospira con mayor frecuencia en el estudio fue georgia (100%), el cual no ha sido descrito en la literatura para equinos. El estudio demuestra la presencia ubicua y simultánea de distintos serovares de Leptospira en equinos

    Toxicidad hematológica asociada al tratamiento con sulfonamidas y pirimetamina en pacientes VIH positivos y toxoplasmosis cerebral en un hospital de tercer nivel en Colombia

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    Objective. To determine the frequency of hematologic adverse effects associated with treatment for cerebral toxoplasmosis in HIV / AIDS patients. Design: Retrospective case series. Location: University Hospital Hernando Moncaleano Perdomo (HMP), Neiva, Colombia. Population. Patients with cerebral toxoplasmosis and HIV / AIDS treated at the infection service unit between 2006 and 2009. Población. Pacientes con toxoplasmosis cerebral y VIH/SIDA atendidos en el servicio de infectología entre 2006-2009. Results. 51 patients were evaluated during the study period. 40 (78%) were men. The average age was 33 years. 25 patients had cerebral toxoplasmosis as the first marker of HIV infection. 60.7% of cases had hematologic toxicity. 42% of patients had anemia before treatment. The peak onset of bone marrow toxicity was the sixth day of the start of treatment schedule. The anti-toxoplasma scheme that was most commonly associated with myelotoxicity was the combination of pyrimethamine/sulfadoxine, trimethoprim-sulfamethoxazole and clindamycin in 48% of cases. Objetivo. Determinar la frecuencia efectos adversos hematológicos asociados al tratamiento para toxoplasmosis cerebral en pacientes VIH/SIDA. Diseño. Serie de casos retrospectiva. Lugar. Hospital Universitario Hernando Moncaleano Perdomo (HMP), Neiva- Colombia. Población. Pacientes con toxoplasmosis cerebral y VIH/SIDA atendidos en el servicio de Infectología entre 2006-2009. Resultados. 51 pacientes fueron evaluados durante el periodo de estudio. 40 (78%) fueron hombres. El promedio de edad fue 33 años. 25 pacientes presentaban toxoplasmosis cerebral como primer marcador de Infección VIH. El 60,7% de los casos presentaron toxicidad hematológica. 42% de los pacientes presentaron anemia previa al tratamiento. El pico de aparición de toxicidad medular fue al sexto día de inicio del esquema de tratamiento. El esquema antitoxoplasma que más comúnmente fue asociado a mielotoxicidad fue la combinación de pirimetamina/sulfadoxina, trimetoprimsulfametoxazol y clindamicina en 48% de los casos

    Abatacept in patients with rheumatoid arthritis and interstitial lung disease: A national multicenter study of 63 patients

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    OBJECTIVE: Interstitial lung disease (ILD) is one of the most serious complications of rheumatoid arthritis (RA). In the present study, we aimed to assess the efficacy of abatacept (ABA) in patients with ILD associated to RA. METHODS: National multicenter, non-controlled, open-label registry study of RA patients with ILD treated with ABA. RESULTS: 63 patients (36 women) with RA-associated ILD undergoing ABA therapy were studied. The mean ± standard deviation age at the time of the study was 63.2 ± 9.8 years. The median duration of RA and ILD from diagnosis were 6.8 and 1 year, respectively. RA was seropositive in 55 patients (87.3%). In 15 (23.8%) of 63 patients the development of ILD was closely related to the administration of synthetic or biologic disease modifying anti-rheumatic drugs. After a follow-up of 9.4 ± 3.2 months, two-thirds of patients remained stable whereas one-quarter experienced improvement in the Modified Medical Research Council scale. At that time forced vital capacity remained stable in almost two-thirds of patents and improved in one out of five patients assessed. Also, diffusing capacity of the lung for carbon monoxide remained stable in almost two-thirds and showed improvement in a quarter of the patients assessed. At 12 months, 50% of the 22 patients in whom chest HRCT scan was performed due persistence of respiratory symptoms showed stabilization, 8 (36.4%) improvement and 3 worsening of the HRCT scan pattern. Eleven of 63 patients had to discontinue ABA, mainly due to adverse events. CONCLUSION: ABA appears to be an effective in RA-associated ILD.Funding: This work was partially supported by RETICS Programs, RD08/0075 (RIER) and RD12/0009/0013 from ‘‘Instituto de Salud Carlos III’’ (ISCIII), Spain

    A DERL3-associated defect in the degradation of SLC2A1 mediates the Warburg effect

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    Cancer cells possess aberrant proteomes that can arise by the disruption of genes involved in physiological protein degradation. Here we demonstrate the presence of promoter CpG island hypermethylation-linked inactivation of DERL3 (Derlin-3), a key gene in the endoplasmic reticulum-associated protein degradation pathway, in human tumours. The restoration of in vitro and in vivo DERL3 activity highlights the tumour suppressor features of the gene. Using the stable isotopic labelling of amino acids in cell culture workflow for differential proteome analysis, we identify SLC2A1 (glucose transporter 1, GLUT1) as a downstream target of DERL3. Most importantly, SLC2A1 overexpression mediated by DERL3 epigenetic loss contributes to the Warburg effect in the studied cells and pinpoints a subset of human tumours with greater vulnerability to drugs targeting glycolysis.Seventh Framework Programme (European Commission) (Grant HEALTH-F5-2010-258236-SYSCOL)Seventh Framework Programme (European Commission) (Grant HEALTH-F2-2011-259015-COLTHERES)Cellex FoundationOlga Torres FoundationEuropean Research Council (EPINORC Project Grant Agreement 268626)Spain. Ministerio de Economia y Competividad (MINECO Project SAF2011-22803)Institute of Health Carlos III (RTICC Grant RD12/0036/0039

    Observation and formation mechanism of 360° domain wall rings in synthetic anti-ferromagnets with interlayer chiral interactions

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    The interlayer Dzyaloshinskii–Moriya interaction (IL-DMI) chirally couples spins in different ferromagnetic layers of multilayer heterostructures. So far, samples with IL-DMI have been investigated utilizing magnetometry and magnetotransport techniques, where the interaction manifests as a tunable chiral exchange bias field. Here, we investigate the nanoscale configuration of the magnetization vector in a synthetic anti-ferromagnet (SAF) with IL-DMI, after applying demagnetizing field sequences. We add different global magnetic field offsets to the demagnetizing sequence in order to investigate the states that form when the IL-DMI exchange bias field is fully or partially compensated. For magnetic imaging and vector reconstruction of the remanent magnetic states, we utilize x-ray magnetic circular dichroism photoemission electron microscopy, evidencing the formation of 360° domain wall rings of typically 0.5–3.0 μm in diameter. These spin textures are only observed when the exchange bias field due to the IL-DMI is not perfectly compensated by the magnetic field offset. From a combination of micromagnetic simulations, magnetic charge distribution, and topology arguments, we conclude that a non-zero remanent effective field with components both parallel and perpendicular to the anisotropy axis of the SAF is necessary to observe the rings. This work shows how the exchange bias field due to IL-DMI can lead to complex metastable spin states during reversal, important for the development of future spintronic devices
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