238 research outputs found

    Microwave heating-induced DC magnetic flux penetration in YBa2_{2}Cu3_{3}O7δ_{7-\delta} superconducting thin films

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    The magneto-optical imaging technique is used to visualize the penetration of the magnetic induction in YBa2_{2}Cu3_{3}O7δ_{7-\delta} thin films during surface resistance measurements. The in-situ surface resistance measurements were performed at 7 GHz using the dielectric resonator method. When only the microwave magnetic field HrfH_{rf} is applied to the superconductor, no HrfH_{rf}-induced vortex penetration is observed, even at high rf power. In contrast, in the presence of a constant magnetic field superimposed on HrfH_{rf} we observe a progression of the flux front as HrfH_{rf} is increased. A local thermometry method based on the measurement of the resonant frequency of the dielectric resonator placed on the YBa2_{2}Cu3_{3}O7δ_{7-\delta} thin film shows that the HrfH_{rf}--induced flux penetration is due to the increase of the film temperature.Comment: 6 pages, Journal of Applied Physic

    Quantifying the Relation between Activity Pattern Complexity and Car Use Using a Partial Least Square Structural Equation Model

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    This paper studies the relationship between activity pattern complexity and car use using two multi-day surveys involving the same participants but collected just before and about one year after they relocated their workplace. Measurable characteristics related to two latent variables, namely activity pattern complexity, or trip chaining (e.g., number of activities done within and outside the home–work tour), and to car use (e.g., usage rate, distance travelled by car) were selected. The study shows that the methodology adopted, partial least square structural equation modelling, quantifies the relation between the two variables, and is robust towards changes in important contextual characteristics of the individuals, namely workplace location. The findings indicate that the number of activities chained to commuting travels strongly impact mode choice and, in particular, car use. The paper also shows that chaining non-work-related activities has a stronger impact on car use. The results of this study suggest that planning and management solutions aimed at reducing car use, but focusing only on the commuting trip while neglecting the impact of other daily activities, may be less effective than expected

    A Synopsis of Serum Biomarkers in Cutaneous Melanoma Patients

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    Many serum biomarkers have been evaluated in melanoma but their clinical significance remains a matter of debate. In this paper, a review of the serum biomarkers for melanoma will be detailed and will be discussed from the point of view of their practical usefulness. The expression of biomarkers can be detected intracellularly or on the cell membrane of melanoma cells or noncancer cells in association with the melanoma. Some of these molecules can then be released extracellularly and be found in body fluids such as the serum. Actually, with the emergence of new targeted therapies for cancer and the increasing range of therapeutic options, the challenge for the clinician is to assess the unique risk/response ratio and the prognosis for each patient. New serum biomarkers of melanoma progression and metastatic disease are still awaited in order to provide efficient rationale for followup and treatment choices. LDH as well as S100B levels have been correlated with poor prognosis in AJCC stage III/IV melanoma patients. However, the poor sensitivity and specificity of those markers and many other molecules are serious limitations for their routine use in both early (AJCC stage I and II) and advanced stages of melanoma (AJCC stage III and IV). Microarray technology and proteomic research will surely provide new candidates in the near future allowing more accurate definition of the individual prognosis and prediction of the therapeutic outcome and select patients for early adjuvant strategies

    Silicon accumulation in maize negatively impacts the feeding and life history traits of Spodoptera exigua Hübner

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    Silicon (Si) accumulation in plant tissues helps alleviate abiotic and biotic stresses, including infestation by insect pests. Here, we tested the hypothesis that Si concentration in maize leaves negatively impacts Spodoptera exigua Hübner (Lepidoptera: Noctuidae) with respect to: (i) feeding preferences; (ii) leaf digestion; and (iii) life history traits. We produced three groups of maize plants cultivated in a hydroponic system that had contrasting Si concentrations in their tissues (i.e., 0.21 ± 0.03, 4.45 ± 0.50 and 8.46 ± 0.61 g Si Kg-1 DW). In choice assays, fifth instars preferentially consumed leaves containing lower Si concentrations. In no choice-assays, we found that the approximate digestibility (AD) of larvae feeding on Si-enriched leaves was not affected. However, these larvae exhibited a 32% reduction in relative growth rates. Higher Si concentration in maize leaves extended larval development by three days; from 18.07 ± 0.29 when feeding on Si- diet to 21.39 ± 0.21 days on the Si++ enriched diet. Silicon also reduced larval survival by 18% and pupal weight by 20%. Our results confirm that Si supplementation in soil enhances the ability of plants to resist infestation with chewing insects, and should be considered as a viable option in the existing range of sustainable management practices

    Exposure assessment of foodborne pathogens in pork in Belgium

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    The aim of this study was to assess the exposure of the most incident foodborne pathogens in the Belgian meat production chain. The prevalence of Salmonella, Campylobacter and Listeria monocytogenes were evaluated in carcasses (swabs), retail cuts, minced meat and meat products of pork. The investigation was made each year since 1997, using official methods from the Ministry of Public Health for Salmonella and Campylobacter and the Vidas Listeria monocytogenes method. More than 10 % of each matrix were contaminated with Salmonella. For minced meat and meat products, the contamination rate were respectively round 20 % and 3 – 6 % for Listeria monocytogenes. Under 5 % of minced meat samples were positive for Campylobacter. For minced meat, the contamination has also been assessed according to the location of sampling (agreed, low capacity establishments or retail level). The characterisation of bacterial species allows the comparison between meat and human isolates

    Regulation of IFN response gene activity during infliximab treatment in rheumatoid arthritis is associated with clinical response to treatment

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    ABSTRACT: INTRODUCTION: Cross-regulation between tumor necrosis factor (TNF) and type I interferon (IFN) has been postulated to play an important role in autoimmune diseases. Therefore we determined the effect of TNF-blockade in rheumatoid arthritis (RA) on the type I IFN-response gene activity in relation to clinical response. METHODS: Peripheral blood from 33 RA patients was collected in PAXgene tubes before and after the start of infliximab treatment. In a first group of 15 patients the baseline expression of type I IFN-regulated genes was determined using cDNA-microarrays and compared to levels one month after treatment. The remaining 18 patients were studied as an independent group for validation using quantitative (q)PCR. RESULTS: Gene expression analysis revealed that anti-TNF antibody treatment induced a significant increase in type I IFN-response activity in a subset of RA patients, whereas expression levels remained similar or were slightly decreased in others. The findings appear clinically relevant since patients with an increased IFN-response gene activity after anti-TNF therapy had a poor clinical outcome. This association was confirmed and extended for an IFN-response gene set consisting of OAS1, LGALS3BP, Mx2, OAS2 and SERPING1 in five EULAR good and five EULAR poor responders, by qPCR. CONCLUSIONS: Regulation of IFN-response gene activity upon TNF-blockade in RA is not as consistent as previously described, but varies between patients. The differential changes in IFN-response gene activity appear relevant to the clinical outcome of TNF-blockade in R

    Genotypic and phenotypic spectrum of pyridoxine-dependent epilepsy (ALDH7A1 deficiency)

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    Pyridoxine-dependent epilepsy was recently shown to be due to mutations in the ALDH7A1 gene, which encodes antiquitin, an enzyme that catalyses the nicotinamide adenine dinucleotide-dependent dehydrogenation of L-{alpha}-aminoadipic semialdehyde/L-{Delta}1-piperideine 6-carboxylate. However, whilst this is a highly treatable disorder, there is general uncertainty about when to consider this diagnosis and how to test for it. This study aimed to evaluate the use of measurement of urine L-{alpha}-aminoadipic semialdehyde/creatinine ratio and mutation analysis of ALDH7A1 (antiquitin) in investigation of patients with suspected or clinically proven pyridoxine-dependent epilepsy and to characterize further the phenotypic spectrum of antiquitin deficiency. Urinary L-{alpha}-aminoadipic semialdehyde concentration was determined by liquid chromatography tandem mass spectrometry. When this was above the normal range, DNA sequencing of the ALDH7A1 gene was performed. Clinicians were asked to complete questionnaires on clinical, biochemical, magnetic resonance imaging and electroencephalography features of patients. The clinical spectrum of antiquitin deficiency extended from ventriculomegaly detected on foetal ultrasound, through abnormal foetal movements and a multisystem neonatal disorder, to the onset of seizures and autistic features after the first year of life. Our relatively large series suggested that clinical diagnosis of pyridoxine dependent epilepsy can be challenging because: (i) there may be some response to antiepileptic drugs; (ii) in infants with multisystem pathology, the response to pyridoxine may not be instant and obvious; and (iii) structural brain abnormalities may co-exist and be considered sufficient cause of epilepsy, whereas the fits may be a consequence of antiquitin deficiency and are then responsive to pyridoxine. These findings support the use of biochemical and DNA tests for antiquitin deficiency and a clinical trial of pyridoxine in infants and children with epilepsy across a broad range of clinical scenarios
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