726 research outputs found

    Superconductivity as a probe of magnetic switching and ferromagnetic stability in Nb/Ni multilayers

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    The temperature and field dependences of the AC and DC magnetic moment of superconducting and ferromagnetic Nb/Ni multilayers were measured using a SQUID magnetometer with magnetic field applied parallel to the multilayer plane. Periodic kinks in the superconducting upper critical field are evidence for nucleation of a hierarchy of Abrikosov vortex lattices aligned parallel to the multilayer. Small cusps in the low-field, isothermal DC magnetization are evidence that supercurrents are sensitive to extremely small changes in the Ni layer magnetization. Smooth ferromagnetic hysteresis is observed in the normal state, but is supplanted below the superconducting transition by two reproducible discontinuities that indicate magnetic switching of the Ni layers is tightly coupled to the supercurrents. The discontinuities are attributed to the non-dipole character of the moment near switching fields and, therefore, cannot be analyzed by standard magnetometer software. Ferromagnetic resonance spectra were measured in parallel and perpendicular DC magnetic fields at room temperature and 4.2 K, and resulting data suggest that Ni layers interact magnetically in the superconducting state

    GLUCONATO CÁLCICO 10% ENDOVENOSO: CUIDADOS DE LAS VÍAS DE INFUSIÓN EN PREMATUROS

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    Administration of 10% calcium gluconate in premature neonates and at due time is a habitual technique, which takes place in neonatal and neonatology ICUs as a complement of the parenteral nutrition administration and when dealing with certain pathologies. In spite of being a usual technique, it can lead to a series of complications which must be controlled. The creation of this protocol allows us to administrate 10% calcium gluconate in a safe way and to try to control the complications that can be associated with it such as extravasation and later calcification.La administración de gluconato cálcico al 10% en neonatos prematuros y a término es una técnica habitual que se desarrolla en las unidades de UCI neonatal y neonatología como complemento a la administración de nutriciones parenterales y ante algunas patologías. A pesar de ser una técnica habitual, puede llevar asociada una serie de complicaciones que debemos controlar. La creación de este protocolo nos permite administrar el gluconato cálcico 10% de forma segura y tratar de controlar las complicaciones que pueden asociarse como la extravasación y posterior calcificación

    Cognitive impairment induced by delta9-tetrahydrocannabinol occurs through heteromers between cannabinoid CB1 and serotonin 5-HT2A receptors

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    Delta-9-tetrahydrocannabinol (THC), the main psychoactive compound of marijuana, induces numerous undesirable effects, including memory impairments, anxiety, and dependence. Conversely, THC also has potentially therapeutic effects, including analgesia, muscle relaxation, and neuroprotection. However, the mechanisms that dissociate these responses are still not known. Using mice lacking the serotonin receptor 5-HT2A, we revealed that the analgesic and amnesic effects of THC are independent of each other: while amnesia induced by THC disappears in the mutant mice, THC can still promote analgesia in these animals. In subsequent molecular studies, we showed that in specific brain regions involved in memory formation, the receptors for THC and the 5-HT2A receptors work together by physically interacting with each other. Experimentally interfering with this interaction prevented the memory deficits induced by THC, but not its analgesic properties. Our results highlight a novel mechanism by which the beneficial analgesic properties of THC can be dissociated from its cognitive side effects

    Comparative Analysis of the Volatile Fraction of Fruit Juice from Different Citrus Species

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    The volatile composition of fruit from four Citrus varieties (Powell Navel orange, Clemenules mandarine, and Fortune mandarine and Chandler pummelo) covering four different species has been studied. Over one hundred compounds were profiled after HS-SPME-GC-MS analysis, including 27 esters, 23 aldehydes, 21 alcohols, 13 monoterpene hydrocarbons, 10 ketones, 5 sesquiterpene hydrocarbons, 4 monoterpene cyclic ethers, 4 furans, and 2 aromatic hydrocarbons, which were all confirmed with standards. The differences in the volatile profile among juices of these varieties were essentially quantitative and only a few compounds were found exclusively in a single variety, mainly in Chandler. The volatile profile however was able to differentiate all four varieties and revealed complex interactions between them including the participation in the same biosynthetic pathway. Some compounds (6 esters, 2 ketones, 1 furan and 2 aromatic hydrocarbons) had never been reported earlier in Citrus juices. This volatile profiling platform for Citrus juice by HS-SPME-GC-MS and the interrelationship detected among the volatiles can be used as a roadmap for future breeding or biotechnological applications

    HDL cholesterol efflux capacity in rheumatoid arthritis patients: contributing factors and relationship with subclinical atherosclerosis

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    Background: Lipid profiles appear to be altered in rheumatoid arthritis (RA) patients because of disease activity and inflammation. Cholesterol efflux capacity (CEC), which is the ability of high-density lipoprotein cholesterol to accept cholesterol from macrophages, has been linked not only to cardiovascular events in the general population but also to being impaired in patients with RA. The aim of this study was to establish whether CEC is related to subclinical carotid atherosclerosis in patients with RA. Methods: We conducted a cross-sectional study that encompassed 401 individuals, including 178 patients with RA and 223 sex-matched control subjects. CEC, using an in vitro assay, lipoprotein serum concentrations, and standard lipid profile, was assessed in patients and control subjects. Carotid intima-media thickness (CIMT) and carotid plaques were assessed in patients with RA. A multivariable analysis was performed to evaluate the relationship of CEC with RA-related data, lipid profile, and subclinical carotid atherosclerosis. Results: Mean (SD) CEC was not significantly different between patients with RA (18.9 ± 9.0%) and control subjects (16.9 ± 10.4%) (p = 0.11). Patients with RA with low (? coefficient ?5.2 [?10.0 to 0.3]%, p = 0.039) and moderate disease activity (? coefficient ?4.6 [?8.5 to 0.7]%, p = 0.020) were associated with lower levels of CEC than patients in remission. Although no association with CIMT was found, higher CEC was independently associated with a lower risk for the presence of carotid plaque in patients with RA (odds ratio 0.94 [95% CI 0.89?0.98], p = 0.015). Conclusions: CEC is independently associated with carotid plaque in patients with RA

    Factors driving patterns and trends in strandings of small cetaceans

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    The incidence of cetacean strandings is expected to depend on a combination of factors, including the dis- tribution and abundance of the cetaceans, their prey, and causes of mortality (e.g. natural, fishery bycatch), as well as currents and winds which affect whether carcasses reach the shore. We investigated spatiotemporal patterns and trends in the numbers of strandings of three species of small cetacean in Galicia (NW Spain) and their relationships with meteoro- logical, oceanographic, prey abundance and fishing-related variables, aiming to disentangle the relationship that may exist between these factors, cetacean abundance and mor- tality off the coast. Strandings of 1166 common dolphins (Delphinus delphis), 118 bottlenose dolphins (Tursiops truncatus) and 90 harbour porpoises (Phocoena phocoena) during 2000–2013 were analysed. Generalised additive and generalised additive-mixed model results showed that the variables which best explained the pattern of strandings of the three cetacean species were those related with local ocean meteorology (strength and direction of the North– South component of the winds and the number of days with South-West winds) and the winter North Atlantic Oscil- lation Index. There were no significant relationships with indices of fishing effort or landings. Only bottlenose dolphin showed possible fluctuations in local abundance over the study period. There was no evidence of long-term trends in number of strandings in any of the species and their abun- dances were, therefore, considered to have been relatively stable during the study period.Versión del editor2,01

    Towards the Physical Map of the Trypanosoma cruzi Nuclear Genome: Construction of YAC and BAC Libraries of the Reference Clone T. cruzi CL-Brener

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    Strategies to construct the physical map of the Trypanosoma cruzi nuclear genome have to capitalize on three main advantages of the parasite genome, namely (a) its small size, (b) the fact that all chromosomes can be defined, and many of them can be isolated by pulse field gel electrophoresis, and (c) the fact that simple Southern blots of electrophoretic karyotypes can be used to map sequence tagged sites and expressed sequence tags to chromosomal bands. A major drawback to cope with is the complexity of T. cruzi genetics, that hinders the construction of a comprehensive genetic map. As a first step towards physical mapping, we report the construction and partial characterization of a T. cruzi CL-Brener genomic library in yeast artificial chromosomes (YACs) that consists of 2,770 individual YACs with a mean insert size of 365 kb encompassing around 10 genomic equivalents. Two libraries in bacterial artificial chromosomes (BACs) have been constructed, BACI and BACII. Both libraries represent about three genome equivalents. A third BAC library (BAC III) is being constructed. YACs and BACs are invaluable tools for physical mapping. More generally, they have to be considered as a common resource for research in Chagas diseaseInstituto de Investigaciones en Ingeniería Genética y Biología MolecularEscola Paulista de MedicinaCBMUniversidade de São PauloUniversidade Federal do Rio de JaneiroIPBUniversidad Central de VenezuelaUSBInstituto Oswaldo CruzCEPHUNIFESP, EPMSciEL
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