250 research outputs found

    Efficient high-resolution 3-D interpolation of meteorological variables for operational use

    Get PDF
    Abstract. In recent years, the use of mesoscale meteorological network data has been growing. An Optimal Interpolation (OI) method is used to interpolate on a regular grid the hourly averaged values of temperature, relative humidity, wind vector, atmospheric pressure, and hourly cumulated precipitation. For all variables, except precipitation, the background (i.e. first guess) information is obtained by detrending the observations using the geographical parameters. For precipitation, the M. Lema radar-derived best estimate of precipitation rate at the ground is used. The characteristics of the OI schemes are shown in several test cases using data from ARPA Lombardia's mesoscale meteorological network. Finally, a quantitative diagnostics for temperature and relative humidity is carried out by using Cross Validation (CV) scores computed with large sets of data

    Localization of apolipoprotein A-I epitopes involved in the activation of lecithin: Cholesterol acyltransferase

    Get PDF
    Eight murine monoclonal antibodies (Mab) to apolipoprotein A-I were characterized for their epitopes and for their ability to interfere with lecithin:cholesterol acyltransferase (LCAT) activation mediated by apo apoA-I using a synthetic substrate. Using overlapping synthetic peptides we have identified six continuous epitopes that span amino acids 1-10 (Mab A-I-19), 96-101 (Mab A-I-15), 133-141 (Mab A-I-5), 140-145 (Mab A-I-9), 144-148 (Mab A-I-8), and 167-174 (Mab A-I-57). Furthermore, antibodies A-I-11 and A-I-16 recognized discontinuous epitopes, namely amino acids 124-128 and 144-148. When antibodies were tested for their ability to inhibit LCAT activation, an inhibitory effect was observed with those whose epitopes covered the area of apoA-I encompassing amino acids 96-174. From these data we conclude that several areas of apoA-I spanning the middle region of the apolipoprotein act in concert to stimulate LCAT activity, possibly by cooperative interaction with the enzyme

    Gold nanoparticles induce cytotoxicity in the alveolar type-II cell lines A549 and NCIH441.

    Get PDF
    International audienceBackground: During the last years engineered nanoparticles (NPs) have been extensively used in different technologies and consequently many questions have arisen about the risk and the impact on human health following exposure to nanoparticles. Nevertheless, at present knowledge about the cytotoxicity induced by NPs is still largely incomplete. In this context, we have investigated the cytotoxicity induced by gold nanoparticles (AuNPs), which differed in size and purification grade (presence or absence of sodium citrate residues on the particle surface) in vitro, in the human alveolar type-II (ATII)-like cell lines A549 and NCIH441

    Treatment of primary shoulder stiffness: Results of a survey on surgeon practice patterns in Italy

    Get PDF
    Objectives Shoulder stiffness is a condition of restricted glenohumeral range of motion (ROM), which can arise spontaneously or as consequence of a known cause. Several treatment options are available and currently no consensus has been obtained on which treatment algorithm represents the best choice for the patient. The aim of this study was to investigate surgeon practice patterns in Italy regarding treatment of primary shoulder stiffness. Methods A literature review was performed to identify randomized controlled trials reporting results of shoulder stiffness treatment. The following controversial or critical points in the treatment of primary shoulder stiffness were identified: modalities of physical therapy; indication for oral corticosteroid; indication and frequency for injective corticosteroid; technique and site of injection; and indication, timing, and technique for surgery. A survey composed by 14 questions was created and adminis-trated to the members of a national association specialized in orthopaedics and sports traumatology (SIGASCOT at the time of survey completion, recently renamed SIA-GASCOT after the fusion of the societies SIGASCOT and SIA). Results A total of 204 completed questionnaires were collected. Physical therapy was recommended by 98% of the interviewed. The use of oral corticosteroids was considered by 51%, and injections of corticosteroids by 72%. The posterior injection approach was the one preferred and a number of three was considered the upper limit for repeated injections. Injective therapy with local anesthetics and hyaluronic acid was considered by more than 20% of the interviewed. Thirty percent of the interviewed did not treat shoulder stiffness surgically. Conclusion Several approaches to shoulder stiffness have been proposed and high-level evidence is available to analyze and discuss their results. Several controversial points emerged both from a literature review and from this national survey. Treatment of shoulder stiffness should be tailored to the patient’s clinical situation and the stage of its pathology and should aim at pain reduction, ROM restoration, functional regain, and shortening of symptoms duration, with conservative therapy remaining the mainstay of treatment

    Retentive device for intravesical drug delivery based on water-induced shape memory response of poly(vinyl alcohol): design concept and 4D printing feasibility

    Get PDF
    The use of shape memory polymers exhibiting water-induced shape recovery at body temperature and water solubility was proposed for the development of indwelling devices for intravesical drug delivery. These could be administered via catheter in a suitable temporary shape, retained in the bladder for a programmed period of time by recovery of the original shape and eliminated with urine following dissolution/erosion. Hot melt extrusion and fused deposition modeling 3D printing were employed as the manufacturing techniques, the latter resulting in 4D printing because of the shape modifications undergone by the printed item over time. Pharmaceutical-grade poly(vinyl alcohol) was selected based on its hot-processability, availability in different molecular weights and on preliminary data showing water-induced shape memory behavior. Specimens having various original and temporary geometries as well as compositions, successfully obtained, were characterized by differential scanning calorimetry and dynamic-mechanical thermal analysis as well as for fluid uptake, mass loss, shape recovery and release behavior. The samples exhibited the desired ability to recover the original shape, consistent in kinetics with the relevant thermo-mechanical properties, and concomitant prolonged release of a tracer. Although preliminary in scope, this study indicated the viability of the proposed approach to the design of retentive intravesical delivery systems

    Interaction of magnetic nanoparticles with U87MG cells studied by synchrotron radiation X-ray fluorescence techniques

    Get PDF
    International audienceSynchrotron radiation (SR) X-ray microscopy combined with X-ray fluorescence (XRF) microspectroscopy provides unique information that have pushed the frontiers of biological research, particularly when investigating intracellular mechanisms. This work reports an SR-XRF microspectroscopy investigation on the distribution and the potential toxicity of Fe 2 O 3 and CoFe 2 O 4 nanoparticles (NPs) in U87MG glioblastoma-astrocytoma cells. The U87MG cells exposed to NPs concentrations ranging from 5 to 250 mg/ml for 24 h were analyzed in order to monitor both morphological and chemical changes. The SR-XRF maps complemented with XRM absorption and phase contrast images have revealed different intracellular distribution patterns for the two nanoparticles types allowing different mechanism of toxicity to be deduced

    Acute Morphological and Toxicological Effects in a Human Bronchial Coculture Model after Sulfur Mustard Exposure.

    Get PDF
    International audienceSulfur mustard (SM) is a strong alkylating agent. Inhalation of SM causes acute lung injury accompanied by severe disruption of the airway barrier. In our study, we tested the acute effects after mustard exposure in an in vitro coculture bronchial model of the proximal barrier. To achieve this, we seeded normal human bronchial epithelial explant-outgrowth cells (HBEC) together with lung fibroblasts as a bilayer on filter plates and exposed the bronchial model after 31 days of differentiation to various concentrations of SM (30, 100, 300, and 500mM). The HBEC formed confluent layers, expressing functional tight junctions as measured by transepithelial electrical resistance (TER). Mucus production and cilia formation reappeared in the coculture model. TER was measured after 2 and 24 h following treatment. Depending on the different concentrations , TER decreased in the first 2 h up to 55% of the control at the highest concentration. After 24 h, TER seemed to recover because at concentrations up to 300mM values were equal to the control. SM induced a widening of intercellular spaces and a loss in cell-matrix adhesion. Mucus production increased with the result that cilia ceased to beat. Changes in the proinflammatory cytokines in-terleukin (IL)-6 and IL-8 were also observed. Apoptotic markers such as cytochrome c, p53, Fas-associated protein with death domain, and procaspase-3 were significantly induced at concentrations of less than 100mM. In summary, SM induces morphological and biochemical changes that reflect pathological effects of SM injury in vivo. It is hoped to use this coculture model to understand further the pathogenesis of SM-induced barrier injury and to search for novel approaches in SM therapy

    Effect of Polyethylene Glycol Content and Molar Mass on Injection Molding of Hydroxypropyl Methylcellulose Acetate Succinate-Based Gastroresistant Capsular Devices for Oral Drug Delivery

    Get PDF
    Capsular devices for oral drug delivery were recently proposed and manufactured by injection molding (IM) as an evolution of traditional reservoir systems comprising a core and a functional coating. IM allowed the fabrication of capsule shells with release-controlling features based on the employed materials and the design characteristics. These features are independent of the drug, with significant savings in development time and costs. In previous work, IM was used to produce enteric-soluble capsules from blends of hydroxypropyl methylcellulose acetate succinate, with polyethylene glycol (PEG) as the plasticizer. In this work, the range of plasticizer concentrations and molar mass was broadened to evaluate in-depth how those parameters affect material processability and capsule performance over time. As expected, increasing the amount of the low molar mass plasticizer decreased the viscosity and modulus of the material. This simplified the molding process and enhanced the mechanical resistance of the shell, as observed during assembly. However, some samples turned out translucent, depending on several factors including storage conditions. This was attributed to plasticizer migration issues. Such results indicate that higher molar mass PEGs, while not significantly impacting on processability, lead to capsular devices with consistent performance in the investigated time lapse

    PCSK9 deficiency reduces insulin secretion and promotes glucose intolerance: the role of the low-density lipoprotein receptor

    Get PDF
    Aims PCSK9 loss of function genetic variants are associated with lower low-density lipoprotein cholesterol but also with higher plasma glucose levels and increased risk of Type 2 diabetes mellitus. Here, we investigated the molecular mechanisms underlying this association. Methods and results Pcsk9 KO, WT, Pcsk9/Ldlr double KO (DKO), Ldlr KO, albumin AlbCre+/Pcsk9LoxP/LoxP (liver-selective Pcsk9 knock-out mice), and AlbCre-/Pcsk9LoxP/LoxP mice were used. GTT, ITT, insulin and C-peptide plasma levels, pancreas morphology, and cholesterol accumulation in pancreatic islets were studied in the different animal models. Glucose clearance was significantly impaired in Pcsk9 KO mice fed with a standard or a high-fat diet for 20\u2009weeks compared with WT animals; insulin sensitivity, however, was not affected. A detailed analysis of pancreas morphology of Pcsk9 KO mice vs. controls revealed larger islets with increased accumulation of cholesteryl esters, paralleled by increased insulin intracellular levels and decreased plasma insulin, and C-peptide levels. This phenotype was completely reverted in Pcsk9/Ldlr DKO mice implying the low-density lipoprotein receptor (LDLR) as the proprotein convertase subtilisin/kexin Type 9 (PCSK9) target responsible for the phenotype observed. Further studies in albumin AlbCre+/Pcsk9LoxP/LoxP mice, which lack detectable circulating PCSK9, also showed a complete recovery of the phenotype, thus indicating that circulating, liver-derived PCSK9, the principal target of monoclonal antibodies, does not impact beta-cell function and insulin secretion. Conclusion PCSK9 critically controls LDLR expression in pancreas perhaps contributing to the maintenance of a proper physiological balance to limit cholesterol overload in beta cells. This effect is independent of circulating PCSK9 and is probably related to locally produced PCSK9
    • …
    corecore