152 research outputs found

    Influence of microwave annealing on GMI response and magnetization of an amorphous Fe73.5Nb3Cu1Si13.5B9 ribbon

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    The resistive and reactive components of magneto-impedance was studied for the as-quenched and microwave annealed amorphous Fe73.5Nb3Cu1Si13.5B9 ribbon as a function of biasing d.c magnetic fields (-60 to +60 Oe) and excitation frequencies (0.1, 1, 10 and 20MHz). The magneto-impedance (both components) response was much reduced for the microwave annealed ribbon and the changes were more discernable at higher excitation frequencies. The imaginary component of magneto-impedance showed maxima at finite (non-zero) d.c magnetic fields for both the as-quenched and microwave annealed ribbons. Magnetization measurements performed for both the as-quenched and microwave annealed ribbons revealed the magnetic hardness of the latter. The initial susceptibility decreases by two orders of magnitude for the microwave-annealed ribbon. XRD measurements indicated the transformation of the surface of the ribbon from the amorphous state to the crystalline one.Comment: 14 pages, 6 figure

    Modeling of torsion stress giant magnetoimpedance in amorphous wires with negative magnetostriction

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    A model describing the influence of torsion stress on the giant magnetoimpedance in amorphous wires with negative magnetostriction is proposed. The wire impedance is found by means of the solution of Maxwell equations together with the Landau-Lifshitz equation, assuming a simplified spatial distribution of the magnetoelastic anisotropy induced by the torsion stress. The impedance is analyzed as a function of the external magnetic field, torsion stress and frequency. It is shown that the magnetoimpedance ratio torsion dependence has an asymmetric shape, with a sharp peak at some value of the torsion stress. The calculated field and stress dependences of the impedance are in qualitative agreement with results of the experimental study of the torsion stress giant magnetoimpedance in Co-based amorphous wires.Comment: 17 pages, 5 figure

    Moisturizing body milk as a reservoir of Burkholderia cepacia: outbreak of nosocomial infection in a multidisciplinary intensive care unit

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    Background: An outbreak of severe nosocomial Burkholderia cepacia infections in patients admitted to intensive care unit (ICU), including investigation of the reservoir, is described. Methods: Over a period of 18 days, isolates of Burkholderia cepacia were recovered from different biological samples from five patients who were admitted to a multidisciplinary 18-bed intensive care unit. Isolation of B. cepacia was associated with bacteraemia in three cases, lower respiratory tract infection in one and urinary tract infection in one. Contact isolation measures were instituted; new samples from the index patients and adjacent patients were collected; and samples of antiseptics, eau de Cologne and moisturizing body milk available in treatment carts at that time were collected and cultured. Results: B. cepacia was isolated from three samples of the moisturizing body milk that had been applied to the patients. Three new hermetically closed units, from three different batches, were sent for culture; two of these were positive as well. All strains recovered from environmental and biological samples were identified as belonging to the same clone by pulsed-field gel electrophoresis. The cream was withdrawn from all hospitalization units and no new cases of B. cepacia infection developed. Conclusion: Moisturizing body milk is a potential source of infection. In severely ill patients, the presence of bacteria in cosmetic products, even within accepted limits, may lead to severe life-threatening infections

    Relació entre el percentatge i número absolut de cèl·lules Natural Killer i de l'expressió dels seus receptors NKG2D i NKp46 i les diferents formes de presentació de la Tuberculosi. Resultats preliminars

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    La tuberculosi pot localitzar-se al pulmó: TB-P o altres òrgans: TB-EP, segons el compromís del sistema immunitari de l'hoste, on hi intervenen les cèl·lules Natural Killer-NK.Tuberculosis is preferably located in the lungs: P-TB or any other organ: EP-TB, depending on the impairment of the immune system of the host that involve Natural Killer cells-NK

    Tuberculosi, infecció i malatia en relació amb nivells de vitamina D

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    La vitamina D té un paper important en patologies infeccioses, entre les quals la tuberculosi. El present estudi pretén avaluar aspectes clínics i epidemiològics de pacients amb infecció tuberculosa en els quals s'han determinat nivells sèrics de vitamina D, i veure si existeix relació entre el dèficit de vitamina D i el risc de desenvolupar malaltia activa, i si aquest dèficit es relaciona més amb malaltia extrapulmonar o greu. És un estudi observacional retrospectiu, en el qual s'han inclós un total de 86 pacients amb malaltia activa i 80 amb infecció latent. No s'objectivà una associació entre major dèficit de vitamina D i malaltia extrapulmonar, ni amb malaltia més greu. En canvi, destacà una associació significativa entre el dèficit greu de vitamina D i la malaltia tuberculosa activa quan es compara amb pacients amb infecció latent

    Factores Asociados a Deficiencia de Vitamina D y a Niveles Elevados de PTH en Pacientes con Infección VIH Atendidos en Barcelona

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    Estudi transversal de pacients VIH en els que es va determinar colecalciferol (25-OH- Vit.D3) i PTH, excloint a pacients amb insuficiència renal, hepàtica i nivells plasmàtics anormals de calci i/o fósfor Es van incloure 566 pacients, amb una exposició a tenofovir del 56,4%. La prevalència de vitamina D insuficient va der del 71,2% i la deficiència del 39,6% . La PTH es va determinar en 228 casos, presentant nivells elevats 86 d'ells (37,7%). Els factors de risc ajustats de deficiència de vitamina D van ser, ésser de raza no blanca i la morbilitat psiquiàtrica, essent la lipoatròfia, un factor protector. Els factors de risc independents de nivells elevats de PTH van ser: Vitamina D 12 ng/ml: OR: 2,14 (IC95%: 1,19-3,82, p: 0,01) i l' exposició a tenofovir: OR: 3,55 (IC95%: 1,62-7,7, p: 0,002).Estudio transversal de pacientes VIH en los que se determinó colecalciferol (25-OH- Vit.D3) y PTH, excluyendo a pacientes con insuficiencia renal, hepática y niveles plasmáticos anormales de calcio y/o fósforo Se incluyeron 566 pacientes, con una exposición a tenofovir del 56,4%. La prevalencia de vitamina D insuficiente fue del 71,2% y la deficiencia del 39,6% . La PTH se determinó en 228 casos, presentando niveles elevados 86 de ellos (37,7%). Los factores de riesgo ajustados de deficiencia de vitamina D fueron ser de raza no blanca y la morbilidad psiquiátrica, siendo la lipoatrofia, un factor protector. Los factores de riesgo independientes de niveles elevados de PTH fueron: Vitamina D 12 ng/ml: OR: 2,14 (IC95%: 1,19-3,82, p: 0,01) y la exposición a tenofovir: OR: 3,55 (IC95%: 1,62-7,7, p: 0,002)

    Tailoring of magnetocaloric response in nanostructured materials: Role of anisotropy

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    The magnetocaloric response of an ensemble of oriented uniaxial magnetic objects, perpendicularly magne- tized to their easy axes, for temperatures close to the blocking temperature is calculated with the aim of demonstrating that the control of the sample’s microstructure makes up an effective way to tailor its magne- tocaloric response. Coexisting positive and negative magnetocaloric effect (MCE) is found for a model mate- rial with a single magnetic phase transition. Both MCE regimes are controlled by the magnitude of the applied magnetic field. As a proof of concept, experimental results for arrays of self-assembled ferromagnetic nano- wires embedded into highly ordered nanoporous anodic alumina templates are shown, suggesting the validity of the numerical calculations

    A web-based and mobile health social support intervention to promote adherence to inhaled asthma medications: randomized controlled trial

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    Background: Online communities hold great potential as interventions for health, particularly for the management of chronic illness. The social support that online communities can provide has been associated with positive treatment outcomes, including medication adherence. There are few studies that have attempted to assess whether membership of an online community improves health outcomes using rigorous designs. Objective: Our objective was to conduct a rigorous proof-of-concept randomized controlled trial of an online community intervention for improving adherence to asthma medicine. Methods: This 9-week intervention included a sample of asthmatic adults from the United Kingdom who were prescribed an inhaled corticosteroid preventer. Participants were recruited via email and randomized to either an “online community” or “no online community” (diary) condition. After each instance of preventer use, participants (N=216) were required to report the number of doses of medication taken in a short post. Those randomized to the online community condition (n=99) could read the posts of other community members, reply, and create their own posts. Participants randomized to the no online community condition (n=117) also posted their medication use, but could not read others’ posts. The main outcome measures were self-reported medication adherence at baseline and follow-up (9 weeks postbaseline) and an objective measure of adherence to the intervention (visits to site). Results: In all, 103 participants completed the study (intervention: 37.8%, 39/99; control: 62.2%, 64/117). MANCOVA of self-reported adherence to asthma preventer medicine at follow-up was not significantly different between conditions in either intention-to-treat (P=.92) or per-protocol (P=.68) analysis. Site use was generally higher in the control compared to intervention conditions. Conclusions: Joining an online community did not improve adherence to preventer medication for asthma patients. Without the encouragement of greater community support or more components to sustain engagement over time, the current findings do not support the use of an online community to improve adherence

    Etravirine Concentrations in Cerebrospinal Fluid in HIV-Infected Patients

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    Cerebrospinal fluid Etravirine concentrations were measured in 12 asymptomatic HIV-infected patients. Median ETR concentration in plasma was 611.5 ng/mL (148-991) and median CSF ETR concentration was 7.24 ng/ml (3.5-17.9). In all cases Etravirine levels were above the IC50 range(0.39-2.4ng/ml) and CSF viral load was 40 copies/ml in all patients with undetectable plasma viral load. Our data suggest that ETR achieves concentrations several times above the IC50 range in CSF. All patients with undetectable plasma viral load were virologically suppressed in CSF while receiving an ETR-containing regimen. ETR may help in controlling HIV-1 in CNS.Les concentracions d'Etravirina (ETR) al liquid cefaloraquidi (LCR) es van mesurar en 12 pacients assimptomàtics infectats de VIH. La concentració mediana d'ETR en plasma va ser de 611,5 ng/mL (148-991) i la concentració mediana d'ETR al LCR va ser de 7.24 ng/mL (3.5-17.9). En tots els casos, els nivells d'Etravirina van estar per damunt de l'interval CI50 (0.39-2.4 ng/ml) i la càrrega viral al LCR va ser 40 còpies/mL en tots els pacients amb càrrega viral plasmàtica indetectable. Aquestes dades suggereixen que l'ETR assoleix concentracions al LCR diverses vegades superiors a l'interval CI50. Tots els pacients amb càrrega viral indetectable van mostrar supressió virològica al LCR mentre van rebre un règim que contenia ETR. L'ETR pot ajudar en el control del HIV-1 al SNC

    Premiar y financiar proyectos de calidad revierte positivamente en el paciente y en el hospital : disminución de la infección causada por catéter venoso central en pacientes no críticos

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    Objectiu: Avaluar una intervenció dirigida a la reducció d'infeccions relacionades amb els catèters venosos centrals (IRC). Mètodes: Estudi pre-postintervenció, 2004-2006. Població d'estudi: pacients portadors de catèter venós central (CVC). La intervenció va consistir en conèixer la situació bassal, identificar factors de risc, i en el segon període realitzar diverses intervencions. Resultats: Es van analitzar 175 i 200 CVC en el període pre i postintervenció, respectivament. Es va observar una incidència de IRC de 20% durant el període preintervenció i de 5,5% en el període post-intervenció (p 0,001). Conclusió: La aplicació de mesures de prevenció ha aconseguit una disminució d'aquestes del 72,5%.Estudio pre-postintervención, 2004-2006. Población de estudio: pacientes portadores de catéter venoso central (CVC). Intervención: conocer la situación basal, identificar factores de riesgo y en un segundo período realizar mejoras. Resultados: Se analizaron 175 y 200 CVC en el periodo pre y postintervención, respectivamente. Se observó IRC de 20% durante el periodo preintervención y de 5,5% post-intervención (p 0,001). Conclusión: La aplicación de medidas de prevención de la IRC ha conseguido una disminución de estas del 72,5 %
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