8,408 research outputs found

    Blood pressure variability: methodological aspects, clinical relevance and practical indications for management

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    Blood pressure is not a static parameter, but rather undergoes continuous fluctuations over time, as a result of the interaction between environmental and behavioural factors on one side and intrinsic cardiovascular regulatory mechanisms on the other side. Increased blood pressure variability (BPV) may indicate an impaired cardiovascular regulation and may represent a cardiovascular risk factor itself, having been associated with increased all-cause and cardiovascular mortality, stroke, coronary artery disease, heart failure, end-stage renal disease, and dementia incidence. Nonetheless, BPV was considered only a research issue in previous hypertension management guidelines, because the available evidence on its clinical relevance presents several gaps and is based on heterogeneous studies with limited standardization of methods for BPV assessment. The aim of this position paper, with contributions from members of the European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability and from a number of international experts, is to summarize the available evidence in the field of BPV assessment methodology and clinical applications and to provide practical indications on how to measure and interpret BPV in research and clinical settings based on currently available data. Pending issues and clinical and methodological recommendations supported by available evidence are also reported. The information provided by this paper should contribute to a better standardization of future studies on BPV, but should also provide clinicians with some indications on how BPV can be managed based on currently available data

    Servicios avanzados en plantas telef贸nicas VOIP

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    Investigaci贸n e implementaci贸n de m煤ltiples servicios avanzados integrados en una planta telef贸nica bajo protocolo IP (Internet Protocol), tales como telefon铆a (VoIP), call center, servicio de chat (mensajer铆a), correo electr贸nico, servicio de IVR (respuesta de voz interactiva), TTS (Text To Speech). Su dimensionamiento para conexi贸n a PSTN (Red telef贸nica p煤blica conmutada) definiendo requerimientos del hardware necesario para la implementaci贸n. Comparativa acerca de la implementaci贸n de estos servicios a trav茅s de la nube y su implementaci贸n f铆sica al contratar un servicio E1, estudio de costos, ventajas y desventajas de cada uno, teniendo en cuenta todas las variables que incidan directamente en la implementaci贸n, diferenciando la conveniencia seg煤n la circunstanci

    Ultrasonic welding of glass reinforced epoxy composites using thermoplastic hybrid interlayers

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    A glass fiber/polypropylene semi-impregnated lamina was added to an epoxy laminate, prior to the resin infusion, to overcome its limited weldability. Ultrasonic welding of the hybrid composite was conducted by varying welding pressure, time, and vibration amplitude, and using the thermoplastic layer as adjoining surface. Welded joints were analyzed by visual inspection, X-ray tomography, and lap shear testing. Welding time significantly influenced the lap-shear strength, the weld interface quality, and the process stability, promoting the proper intermixing of the thermoplastic layer and the formation of a weld area with strong adhesion. Amplitude and pressure, on the other hand, mostly affected the power absorption. Lower pressure, intermediate amplitude, and longer duration led to an improvement in the lap-shear strength (approximately 5 MPa in the best case). High strength was linked to high exposed-fiber surface area in the fracture surface, while its reduction was attributed to the presence of unwelded areas within the polypropylene interface. X-ray tomography highlighted the correlation between the occurrence of defects in the weld interface and the power profiles, where multiple peaks indicated the material friction and a progressive intermixing of the polymeric interlayer, while flattened profiles and lower peaks are associated to discontinuous and poorly adherent interfaces

    Structural basis of peptidoglycan synthesis by E. coli RodA-PBP2 complex

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    Peptidoglycan (PG) is an essential structural component of the bacterial cell wall that is synthetized during cell division and elongation. PG forms an extracellular polymer crucial for cellular viability, the synthesis of which is the target of many antibiotics. PG assembly requires a glycosyltransferase (GT) to generate a glycan polymer using a Lipid II substrate, which is then crosslinked to the existing PG via a transpeptidase (TP) reaction. A Shape, Elongation, Division and Sporulation (SEDS) GT enzyme and a Class B Penicillin Binding Protein (PBP) form the core of the multi-protein complex required for PG assembly. Here we used single particle cryo-electron microscopy to determine the structure of a cell elongation-specific E. coli RodA-PBP2 complex. We combine this information with biochemical, genetic, spectroscopic, and computational analyses to identify the Lipid II binding sites and propose a mechanism for Lipid II polymerization. Our data suggest a hypothesis for the movement of the glycan strand from the Lipid II polymerization site of RodA towards the TP site of PBP2, functionally linking these two central enzymatic activities required for cell wall peptidoglycan biosynthesis

    Modeling the shape of additive manufactured parts

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    The additive manufactured parts can be made by the use of suitable layer thicknesses of the polymer in order to respect the requirements of a refined geometry and of a surface appearance of the physical object that should be as similar as possible to the original CAD model. An other important variable is the digital datum that can represent a key variable of the realization procedure. The methodology proposed and followed in the present investigation got the objective to get a physical model, through the information obtained by a 3D scanning device, taking into consideration not only the digital treatment but also the building direction to guide the FDM layer deposition in order to realize the required surface appearance. The profiles of the specimen in the digital environment were compared to each other before realizing. The physical object obtained after digital treatment was similar to the one obtained by the original CAD

    Outcomes Following Radiofrequency Renal Denervation According to Antihypertensive Medications: Subgroup Analysis of the Global SYMPLICITY Registry DEFINE

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    BACKGROUND: The Global SYMPLICITY Registry DEFINE investigates radiofrequency renal denervation (RDN) in a broad range of patients with hypertension. We evaluated whether the number or type of antihypertensive medications were associated with increased long-term blood pressure (BP) reductions and cardiovascular outcomes following radiofrequency RDN. METHODS: Patients underwent radiofrequency RDN and were categorized by baseline number (0-3 and 鈮4) and different combinations of medication classes. BP changes were compared between groups through 36 months. Individual and composite major adverse cardiovascular events were analyzed. RESULTS: Of 2746 evaluable patients, 18% were prescribed 0 to 3 and 82% prescribed 鈮4 classes. At 36 months, office systolic BP significantly decreased (P<0.0001) by -19.0卤28.3 and -16.2卤28.6 mm鈥塇g in the 0 to 3 and 鈮4 class groups, respectively. Twenty-four-hour mean systolic BP significantly decreased (P<0.0001) by -10.7卤19.7 and -8.9卤20.5 mm鈥塇g, respectively. BP reduction was similar between the medication subgroups. Antihypertensive medication classes decreased from 4.6卤1.4 to 4.3卤1.5 (P<0.0001). Most decreased (31%) or had no changes (47%) to the number of medications, while 22% increased. The number of baseline antihypertensive medication classes was inversely related to the change in prescribed classes at 36 months (P<0.001). Cardiovascular event rates were generally low. More patients in the 鈮4 compared with 0 to 3 medication classes had myocardial infarction at 36 months (2.8% versus 0.3%; P=0.009). CONCLUSIONS: Radiofrequency RDN reduced BP safely through 36 months, independent of the number and type of baseline antihypertensive medication classes. More patients decreased than increased their number of medications. Radiofrequency RDN is a safe and effective adjunctive therapy regardless of antihypertensive medication regimen. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01534299

    Tensile properties and sustainability assessment of vat photopolymerization 3D printed components with recovered plastic filler

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    Raw material production represents one of the major issues of additive manufacturing as it can be an expensive and environmentally impactful phase. One example is provided by the light-curing resins used in vat photopolymerization processes. To this purpose, this study aims at evaluating the use of recovered polyamide powders as filler for photocurable resins from different perspectives; to this purpose, tensile tests were performed in order to evaluate the effect of recovered powder content as filler on the mechanical properties of the resin. Furthermore, a scanning electron microscopy and computed tomography analyses were carried out to investigate the fracture mechanisms and dispersion of the filler within the resin. Finally, a life cycle assessment analysis was performed to evaluate the effect of different reused power contents as filler on the environmental impact of 3D printed components. Results showed that the use of recovered powder as filler for light-curing resin in vat photopolymerization 3D printing parts allows the obtaining of an improvement in terms of tensile strength and elastic modulus up to 62% and 107%, respectively. In addition, a reduction in environmental impacts up to 48% was obtained. A homogeneous dispersion of the particles within the resin was observed at the different filler contents investigated

    Sorbed environmental contaminants increase the harmful effects of microplastics in adult zebrafish, Danio rerio

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    : Aquatic animals ingest Microplastics (MPs) which have the potential to affect the uptake and bioavailability of sorbed co-contaminants. However, the effects on living organisms still need to be properly understood. The present study was designed to assess the combined effects of MPs and environmental contaminants on zebrafish (Danio rerio) health and behavior. Adult specimens were fed according to three different protocols: 1) untreated food (Control group); 2) food supplemented with 0.4&nbsp;mg/L pristine polyethylene-MPs (PE-MPs; 0.1-0.3&nbsp;mm diameter) (PEv group); 3) food supplemented with 0.4&nbsp;mg/L PE-MPs previously incubated (PEi group) for 2 months in seawater. Analysis of contaminants in PEi detected trace elements, such as lead and copper. After 15 days of exposure, zebrafish underwent behavioral analysis and were then dissected to sample gills and intestine for histology, and the latter also for microbiome analysis. Occurrence of PEv and PEi in the intestine and contaminants in the fish carcass were analyzed. Both PEv- and PEi-administered fish differed from controls in the assays performed, but PEi produced more harmful effects in most instances. Overall, MPs after environmental exposure revealed higher potential to alter fish health through combined effects (e.g. proportion of microplastics, pollutants and/or microorganisms)
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