459 research outputs found

    Takeoff and landing on slopes via inclined hovering with a tethered aerial robot

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    In this paper we face the challenging problem of takeoff and landing on sloped surfaces for a VTOL aerial vehicle. We define the general conditions for a safe and robust maneuver and we analyze and compare two classes of methods to fulfill these conditions: free-flight vs. passivelytethered. Focusing on the less studied tethered method, we show its advantages w.r.t. the free-flight method thanks to the possibility of inclined hovering equilibria. We prove that the tether configuration and the inclination of the aerial vehicle w.r.t. the slope are flat outputs of the system and we design a hierarchical nonlinear controller based on this property. We then show how this controller can be used to land and takeoff in a robust way without the need of either a planner or a perfect tracking. The validity and applicability of the method in the real world is shown by experiments with a quadrotor that is able to perform a safe landing and takeoff on a sloped surface

    Investigation of the prevalence of antibodies against neurotropic polyomaviruses BK, JC and SV40 in sera from patients affected by multiple sclerosis.

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    Viral agents seem to be linked to multiple sclerosis (MS). This association is based on evidence of (1) early exposure to viruses and MS onset; (2) increased prevalence of MS disease in specific geographic regions; (3) likelihood of developing MS being more prevalent in high-risk areas; (4) altered immune responses to different viruses. In this study, sera from patients affected by MS and controls, represented by sera from patients with other neurologic diseases, both inflammatory and non-inflammatory, and from healthy donors, were investigated for the presence of antibodies against neurotropic polyomaviruses BKV, JCV and SV40 in their sera. Our study has indicated that the prevalence of BKV antibodies in sera from MS patients is higher than that detected in normal individuals, while levels of antibodies against BKV and JCV are lower in MS patients compared to those of normal subjects

    Enhancement of the Biological and Mechanical Performances of Sintered Hydroxyapatite by Multiple Ions Doping

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    In the present work, hydroxyapatite (HA) nanoparticles doped with Mg2+, Sr2+, and Zn2+ ions are developed by wet neutralization method and then sintered at 1,250°C to obtain bulk consolidated materials. Physicochemical and microstructural analyses show that the presence of doping ions in the HA structure induced the formation of βTCP as secondary phase, during the sintering process, and we found that this effect is depending on the stability of the various doping ions in the hydroxyapatite lattice itself. We also found that the formation of βTCP as secondary phase, in turn, confines the grain growth of HA induced by the high-temperature sintering process, thus leading to a strong increase of the flexural strength of the bulk materials, according to Hall-Petch-like law. Furthermore, we found that the doping ions enter also in the structure of the βTCP phase; besides the grain growth confinement, also the solubility and ion release ability of the final materials were enhanced. In addition to ameliorate the mechanical performance, the described phenomena also activate multiple biofunctionalities: (i) ability to upregulate various genes involved in the osteogenesis, as obtained by human adipose stem cells culture and evaluated by array technology; (ii) enhanced resistance to the adhesion and proliferation of Gram+ and Gram– bacterial strains. Hence, our results open a perspective for the use of sintered multiple ion-doped HA to develop ceramic biodevices, such as plates, screws, or other osteosynthesis media, with enhanced strength, osteointegrability, and the ability to prevent post-surgical infections

    Unique features of the mode of action of ET-743

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    This paper describes the current knowledge of the primary mode of action of a natural product, ecteinascidin 743 (ET-743), derived from the marine tunicate Ecteinascidia turbinata. ET-743 was initially selected for preclinical development because of its potent antitumor activity observed against several human solid tumor types. In vitro, the drug is cytotoxic in the nanomolar range, and in the case of some very sensitive cell lines, in the picomolar range. The large potency differences observed among several solid tumor types indicate that this compound possesses some tumor selectivity, but the molecular basis of these differential effects remains to be elucidated. The present studies were undertaken to evaluate the mechanism of action of ET-743 in this context. The available information on ET-743 binding to DNA and its effects on transcriptional regulation point to a unique behavior of this drug, as it independently affects specific gene transcription in a promoter-dependent way. In addition, ET-743 shows a peculiar pattern of selectivity in cells with different defects in their DNA-repair pathways. These results highlight a unique property of ET-743, possibly explaining why it possesses antitumor activity against tumors that are refractory to standard anticancer drugs, all of which certainly act by mechanisms that are different from that of ET-743

    Methylglyoxal, Glycated Albumin, PAF, and TNF-α: Possible Inflammatory and Metabolic Biomarkers for Management of Gestational Diabetes

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    Background: In gestational diabetes mellitus (GDM), pancreatic \u3b2-cell breakdown can result from a proinflammatory imbalance created by a sustained level of cytokines. In this study, we investigated the role of specific cytokines, such as B-cell activating factor (BAFF), tumor necrosis factor \u3b1 (TNF-\u3b1), and platelet-activating factor (PAF), together with methylglyoxal (MGO) and glycated albumin (GA) in pregnant women affected by GDM. Methods: We enrolled 30 women whose inflammation and metabolic markers were measured at recruitment and after 12 weeks of strict dietetic therapy. We compared these data to the data obtained from 53 randomly selected healthy nonpregnant subjects without diabetes, hyperglycemia, or any condition that can affect glycemic metabolism. Results: In pregnant women affected by GDM, PAF levels increased from 26.3 (17.4-47.5) ng/mL to 40.1 (30.5-80.5) ng/mL (p < 0.001). Their TNF-\u3b1 levels increased from 3.0 (2.8-3.5) pg/mL to 3.4 (3.1-5.8) pg/mL (p < 0.001). The levels of methylglyoxal were significantly higher in the women with GDM (p < 0.001), both at diagnosis and after 12 weeks (0.64 (0.46-0.90) \u3bcg/mL; 0.71 (0.47-0.93) \u3bcg/mL, respectively) compared to general population (0.25 (0.19-0.28) \u3bcg/mL). Levels of glycated albumin were significantly higher in women with GDM (p < 0.001) only after 12 weeks from diagnosis (1.51 (0.88-2.03) nmol/mL) compared to general population (0.95 (0.63-1.4) nmol/mL). Conclusion: These findings support the involvement of new inflammatory and metabolic biomarkers in the mechanisms related to GDM complications and prompt deeper exploration into the vicious cycle connecting inflammation, oxidative stress, and metabolic results

    Adherence to a Mediterranean-like dietary pattern in children from eight European countries : the IDEFICS study

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    BACKGROUND: Despite documented benefits of a Mediterranean-like dietary pattern, there is a lack of knowledge about how children from different European countries compare with each other in relation to the adherence to this pattern. In response to this need, we calculated the Mediterranean diet score (MDS) in 2-9-year-old children from the Identification and prevention of dietary-and lifestyle-induced health effects in children and infants (IDEFICS) eight-country study. SUBJECTS AND METHODS: Using 24 h dietary recall data obtained during the IDEFICS study (n = 7940), an MDS score was calculated based on the age- and sex-specific population median intakes of six food groups (vegetables and legumes, fruit and nuts, cereal grains and potatoes, meat products and dairy products) and the ratio of unsaturated to saturated fats. For fish and seafood, which was consumed by 10% of the population, one point was given to consumers. The percentages of children with high MDS levels (43) were calculated and stratified by sex, age and by having at least one migrant parent or both native parents. Demographic (sex and age) and socioeconomic characteristics (parental education and income) of children showing high (43) vs low (<= 3) MDS levels were examined. RESULTS: The highest prevalence of children with MDS 43 was found among the Italian pre-school boys (55.9%) and the lowest among the Spanish school-aged girls (26.0%). Higher adherence to a Mediterranean-like dietary pattern was not associated with living in a Mediterranean country or in a highly educated or high-income family, although with some exceptions. Differences in adherence between boys and girls or age groups varied between countries without any general pattern. CONCLUSIONS: With the exception of Italian pre-schoolers, similar adherence levels to a Mediterranean-like dietary pattern have been observed among European children

    Associations between energy intake, daily food intake and energy density of foods and BMI z-score in 2-9-year-old European children

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    The aim of this study was to investigate the associations between proxy-reported energy intake, daily food intake and energy density of foods and body mass index (BMI) z-score in 2-9-year-old European children. From 16,225 children who participated in the identification and prevention of dietary- and lifestyle-induced health effects in children and infants (IDEFICS) baseline examination, 9,782 children with 24-h proxy dietary information and complete covariate information were included in the analysis. Participating children were classified according to adapted Goldberg cutoffs: underreports, plausible energy reports and overreports. Energy intake, daily food intake and energy density of foods excluding noncaloric beverages were calculated for all eating occasions. Effect of energy intake, daily food intake and energy density of foods on BMI z-score was investigated using multilevel regression models in the full sample and subsample of plausible energy reports. Exposure variables were included separately; daily food intake and energy intake were addressed in a combined model to check for interactions. In the group of plausible energy reports (N = 8,544), energy intake and daily food intake were significantly positively associated with BMI z-score. Energy density of foods was not associated with BMI z-score. In the model including energy intake, food intake and an interaction term, only energy intake showed a significantly positive effect on BMI z-score. In the full sample (N = 9,782), only energy intake was significantly but negatively associated with BMI z-score. Proxy-reporters are subject to misreporting, especially for children in the higher BMI levels. Energy intake is a more important predictor of unhealthy weight development in children than daily food intake

    Smart nanofibers with natural extracts prevent senescence patterning in a dynamic cell culture model of human skin

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    Natural cosmetic products have recently re-emerged as a novel tool able to counteract skin aging and skin related damages. In addition, recently achieved progress in nanomedicine opens a novel approach yielding from combination of modern nanotechnology with traditional treatment for innovative pharmacotherapeutics. In the present study, we investigated the antiaging effect of a pretreatment with Myrtus communis natural extract combined with a polycaprolactone nanofibrous scaffold (NanoPCL-M) on skin cell populations exposed to UV. We set up a novel model of skin on a bioreactor mimicking a crosstalk between keratinocytes, stem cells and fibroblasts, as in skin. Beta-galactosidase assay, indicating the amount of senescent cells, and viability assay, revealed that fibroblasts and stem cells pretreated with NanoPCL-M and then exposed to UV are superimposable to control cells, untreated and unexposed to UV damage. On the other hand, cells only exposed to UV stress, without NanoPCL-M pretreatment, exhibited a significantly higher yield of senescent elements. Keratinocyte-based 3D structures appeared disjointed after UV-stress, as compared to NanoPCL-M pretreated samples. Gene expression analysis performed on different senescence associated genes, revealed the activation of a molecular program of rejuvenation in stem cells pretreated with NanoPCL-M and then exposed to UV. Altogether, our results highlight a future translational application of NanoPCL-M to prevent skin aging

    Mortalité des Patients Hémodialysés Chroniques au Bénin : Une Etude Rétrospective sur 6 Ans

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    Introduction: La dialyse est l’une des dernières alternatives dans l’arsenal thérapeutique, capable de maintenir en vie un patient insuffisant rénale chronique terminale. Avant la mise en place de la dialyse au Benin l’insuffisance rénale chronique terminale était systématiquement mortelle. Cette étude avait pour objectif de mettre à jour les données épidémiologiques sur les hémodialysés, la mortalité due à l’insuffisance rénale chronique terminale au CHUD du Borgou Alibori et les facteurs associés à la mortalité due hémodialysés. Cadre et méthodes d’étude : Elle a été réalisée dans le service de néphrologie dudit hôpital. Il s’agissait d’une étude transversale, descriptive à visée analytique qui s’est déroulé du 25 décembre 2022 au 15 mars 2023 et a porté sur les données de 2017 à 2022. Elle a concerné 95 dossiers de patients hémodialysés recruté par commodité et répondant aux critères d’inclusion. Le traitement et l’analyse des données a été faite avec le logiciel SPSS 26. Résultats: Le taux de mortalité était de 80% des hémodialysés. L’âge médian des patients était de 44 ans. Les prédicteurs potentiel de la mortalité des hémodialysés du service de néphrologie du CHUD/B-A étaient le travail en indépendant et secteur informel (p=0,004), le faible revenu mensuel (p=0,017), l’hypoglycémie (p=0,011), un nombre élevé de médicament (p=0,004), la mauvaise observance thérapeutique (p=0,003) et un court séjour en dialyse (p&lt;0,000). Conclusión: Le projet d’assurance pour le renforcement du capital humain est une porte de sortie pour diminuer la mortalité de l’hémodialyse ainsi que le renforcement de la lutte contre les MNT. &nbsp; Introduction: Dialysis is one of the last alternatives in the therapeutic arsenal, capable of keeping a patient with chronic end-stage renal disease alive. Before the introduction of dialysis in Benin, end-stage renal disease was systematically fatal. The aim of this study was to update epidemiological data on hemodialysis patients, mortality due to end-stage renal failure at the CHUD du Borgou Alibori, and factors associated with mortality due to hemodialysis. Study setting and methods: The study was carried out in the hospital's nephrology department. It was a cross-sectional, descriptive study with analytical aims that ran from December 25, 2022 to March 15, 2023 and covered data from 2017 to 2022. It involved 95 hemodialysis patient records recruited by convenience and meeting the inclusion criteria. Data processing and analysis was performed using SPSS 26 software. Results: The mortality rate was 80% for hemodialysis patients. The median age of patients was 44 years. Potential predictors of mortality in hemodialysis patients at the CHUD/B-A nephrology department were self-employment and informal sector (p=0.004), low monthly income (p=0.017), hypoglycemia (p=0.011), high number of medications (p=0.004), poor compliance (p=0.003) and short dialysis stay (p&lt;0.000). Conclusion: The insurance project for strengthening human capital is a way out to reduce hemodialysis mortality and strengthen the fight against NCDs
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