140 research outputs found

    Special cantilever geometry for the access of higher oscillation modes in atomic force microscopy

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    Employing higher oscillation modes of microcantilevers promises higher sensitivity when applied as sensors, for example, for mass detection or in atomic force microscopy. Introducing a special cantilever geometry, we show that the relation between the resonance frequencies of the first and second resonance modes can be modified to separate them further or to bring them closer together. In atomic force microscopy the latter is of special interest as the photodiode of the beam deflection detection limits the accessible frequency range. Using finite element simulations, we optimized the design of the modified cantilever geometry for a maximum reduction of the frequency of the second oscillation mode with respect to the first mode. Cantilevers were fabricated by silicon micromachining and subsequently utilized in an ultrahigh vacuum Kelvin probe force microscope imaging the surface potential of C60 on graphit

    Multidisciplinary consensus on inhaled therapy in asthma

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    Altres ajuts: Mundipharma Pharmaceuticals SL.Background: Asthma is managed by health professionals from different specialties. We aim to reach a consensus on the optimal use of inhaled therapy and the initial steps of asthma treatment, taking into account the opinions of the involved specialists. Methods: A modified Delphi approach was used. A scientific committee provided 52 controversial statements, which were submitted to primary care physicians, allergists, and pulmonologists. Discrepancies among specialties were evaluated. Results: A total of 209 specialists completed the questionnaire (20.2 ± 9.3 years of asthma management experience). A consensus was reached on 37 statements (71.1%), discrepancies among specialties were found in 14. The most recommended maintenance treatment for mild persistent asthma in adults/adolescents was low-dose-inhaled corticosteroids daily. MART (Maintenance and Reliever Therapy) was recommended as salvage treatment for moderate persistent asthma. Panelists agreed on the most frequent critical errors with pressurized Metered-Dose Inhalers or Dry-Powder Inhalers, and considered that Breath-Actuated Inhalers are a suitable option for all patients with the ability to inhale voluntarily. Conclusions: The experts endorse the main guidelines recommendations; however, do not fully agree on recent GINA recommendations about the treatment of the initial steps of the disease. The experts value positively the differential characteristics of BAI over other devices

    Comparison of Several Algorithms to Estimate Activity Counts with Smartphones as an Indication of Physical Activity Level

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    Background Dedicated devices like GT3X+, Actical or ActivPal have been widely used to measure physical activity (PA) levels by using cut-points on activity counts. However, the calculation of activity counts relies on proprietary software. Since smartphones incorporate accelerometers they are suitable candidates to determine PA levels in a wider population. Objective Our aim was to compare several algorithms so that smartphones can reproduce the results obtained with GT3X+. The influence of smartphone location was also investigated. Methods Volunteers participated in the experiment performing several activities carrying two smartphones (hip and pocket) and one GT3X+ (hip). Four algorithms (A1–A4) were considered to obtain GT3X+ counts from smartphone accelerometer signals. A1 was based on a traditional filtering on temporal domain and a posterior calculation of the area under the curve. A2 was based on computing histograms of acceleration values, which were used as independent variables in a standard linear regression procedure. A3 also used a linear regression, but in this case the independent variables were power spectrum bands, leading to a kind of filtering in the frequency domain. A4 was based on a direct measure of area under the rectified curve of the raw accelerometer signal. Performance was measured in terms of raw activity counts or the corresponding PA level classification. The influence of the algorithm was tested with a Quade test. Multiple comparisons were performed with Wilcoxon test with Bonferroni's correction. Besides, battery consumption was also measured as a secondary parameter. The output of the selected algorithm was compared with GT3X+ counts using correlation (pearson and spearman) and agreement (Intra-Class Coefficient, ICC and Bland–Altmann plots for raw counts, and weighted kappa for activity levels). Several experimental conditions regarding smartphone location were compared with Wilcoxon tests. Results Thirty-two volunteers participated in the experiment. More refined algorithms based on filtering techniques did not prove to achieve better performance than A2 or A4. In terms of classification of PA level, A4 got the lowest error rate, although in some cases the differences with other algorithms were not statistically significant (p-value > 0.05). A4 is also the simplest and the one that implies less battery depletion. The comparison of A4 with GT3X+ gave good agreement () and correlation () for raw counts and good agreement when classifying four or two PA levels ( or 0.923 respectively). Besides, in real situations, activity classification into four levels was significantly improved () if data from several body locations were used to find model parameters. Conclusions Simple algorithms can reproduce the results of GT3X+. Thus, smartphones could be used to control the fulfillment of PA recommendations previously validated with cut-points. However, it must be acknowledged that accelerometers are not the gold standard to measure PA

    Performance of Slow-Growing Chickens Fed with Tenebrio molitor Larval Meal as a Full Replacement for Soybean Meal

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    Insect larval meal is an increasingly common protein source in poultry systems. In this study, the effect of replacing soybean meal with Tenebrio molitor larval meal on the performance of slow-growing chickens was assessed. A total of 128 one-day-old chickens (Colorield) were randomly divided into a control group (C) (n = 64), fed with soybean meal, and an experimental group (TM) (n = 64), fed with T. molitor larvae meal. The chicks were slaughtered after 95 days. Three different isoenergetic and isoproteic diets (F1, F2 and F3) were used for each group. The F1 diet resulted in higher body weight gain and higher feed and water intakes in group C, but a lower feed conversion ratio. Contrarily, diets F2 and F3 did not produce differences in the studied parameters between the two groups, except for body weight gain in the case of diet F2, which was highest in group C. Therefore, weight gain and feed and water intakes were significantly higher in group C, but there were no differences in feed conversion ratio or live weight. In conclusion, the total replacement of soybean meal with T. molitor larvae meal resulted in a reduction in feed intake and a consequent reduction in weight. During this period, partial rather than total substitution may be recommended. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

    High power ultrasounds: A powerful, non-thermal and green technique for improving the phenolic extraction from grapes to must during red wine vinification

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    Wine color is one of the main organoleptic characteristics influencing its quality. It is of especial interest in red vinifications due to the economic resources that wineries have to invest for the extraction of the phenolic compounds. To increase this extraction, some chemical (maceration enzymes) or physical technologies (thermovinification, criomaceration, flash-expansion) can be applied. In this work, the results of the application of high power ultrasounds to the crushed grapes to increase the extraction of phenolic compounds are presented. Crushed grapes (400 kg) from the 2017 harvest were treated with ultrasound, and three different lengths of skin maceration period (2, 3 or 7 days) and the results were compared with a control vinification, where grapes were not subjected to any treatment and were skin macerated during 7 days. The wine chromatic characteristics and the individual phenolic compounds were followed during all the maceration period, at the end of alcoholic fermentation and after bottle storage. The wines made with ultrasound treated grapes presented differences with control wine, especially as regard color and total phenol and tannin content, the wines with three days of maceration time presenting similar chromatic characteristics than control wines with 7 days of maceration time

    Integrating magnetic capabilities to intracellular chips for cell trapping

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    Current microtechnologies have shown plenty of room inside a living cell for silicon chips. Microchips as barcodes, biochemical sensors, mechanical sensors and even electrical devices have been internalized into living cells without interfering their cell viability. However, these technologies lack from the ability to trap and preconcentrate cells in a specific region, which are prerequisites for cell separation, purification and posterior studies with enhanced sensitivity. Magnetic manipulation of microobjects, which allows a non-contacting method, has become an attractive and promising technique at small scales. Here, we show intracellular Ni-based chips with magnetic capabilities to allow cell enrichment. As a proof of concept of the potential to integrate multiple functionalities on a single device of this technique, we combine coding and magnetic manipulation capabilities in a single device. Devices were found to be internalized by HeLa cells without interfering in their viability. We demonstrated the tagging of a subpopulation of cells and their subsequent magnetic trapping with internalized barcodes subjected to a force up to 2.57 pN (for magnet-cells distance of 4.9 mm). The work opens the venue for future intracellular chips that integrate multiple functionalities with the magnetic manipulation of cells

    miR-371a-3p, miR-373-3p and miR-367-3p as Serum Biomarkers in Metastatic Testicular Germ Cell Cancers Before, During and After Chemotherapy

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    Background: LDH (lactate dehydrogenase), AFP (alpha-fetoprotein) and \xce\xb2-HCG (human \nchorionic gonadotropin) are used in diagnosis and follow-up of testicular germ cell cancer (TGCC) \npatients. Our aim was to investigate the association between levels of miR-371a-3p, miR-373-3p \nand miR-367-3p and clinical features in metastatic TGCC. Methods: relative levels of miR-371a-3p, \nmiR-373-3p and miR-367-3p were evaluated in serum of metastatic TGCC patients. A prospectively \nincluded and a retrospectively selected cohort were studied (total patient number = 109). Blood \nsamples were drawn at start of chemotherapy and during follow-up. Serum microRNA (miR) \nlevels were determined using the ampTSmiR test. Results: at start of chemotherapy, miR-371a-3p, \nmiR-373-3p and miR-367-3p levels were positively correlated to LDH. The median level of these miRs \nwas higher in patients who developed a relapse after complete biochemical remission (n = 34) than \nin those who had complete durable remission (n = 60). Higher levels of miR-367-3p were found in \npatients with refractory disease (n = 15) compared to those who had complete response. miR levels \ndecreased during the first week of chemotherapy in patients with complete response and stayed \nbelow threshold after one year of treatment. Conclusion: high miR levels at start of chemotherapy \nare associated with worse clinical outcome and can assist in early diagnosing of relapses

    Arsenic exposure, diabetes-related genes and diabetes prevalence in a general population from Spain

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    Inorganic arsenic exposure may be associated with diabetes, but the evidence at low-moderate levels is not sufficient. Polymorphisms in diabetes-related genes have been involved in diabetes risk. We evaluated the association of inorganic arsenic exposure on diabetes in the Hortega Study, a representative sample of a general population from Valladolid, Spain. Total urine arsenic was measured in 1451 adults. Urine arsenic speciation was available in 295 randomly selected participants. To account for the confounding introduced by non-toxic seafood arsenicals, we designed a multiple imputation model to predict the missing arsenobetaine levels. The prevalence of diabetes was 8.3%. The geometric mean of total arsenic was 66.0 µg/g. The adjusted odds ratios (95% confidence interval) for diabetes comparing the highest with the lowest tertile of total arsenic were 1.76 (1.01, 3.09) and 2.14 (1.47, 3.11) before and after arsenobetaine adjustment, respectively. Polymorphisms in several genes including IL8RA, TXN, NR3C2, COX5A and GCLC showed suggestive differential associations of urine total arsenic with diabetes. The findings support the role of arsenic on diabetes and the importance of controlling for seafood arsenicals in populations with high seafood intake. Suggestive arsenic-gene interactions require confirmation in larger studies
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