569 research outputs found

    Screening of AAA

    Get PDF

    MIDAS: Automated Approach to Design Microwave Integrated Inductors and Transformers on Silicon

    Get PDF
    The design of modern radiofrequency integrated circuits on silicon operating at microwave and millimeter-waves requires the integration of several spiral inductors and transformers that are not commonly available in the process design-kits of the technologies. In this work we present an auxiliary CAD tool for Microwave Inductor (and transformer) Design Automation on Silicon (MIDAS) that exploits commercial simulators and allows the implementation of an automatic design flow, including three-dimensional layout editing and electromagnetic simulations. In detail, MIDAS allows the designer to derive a preliminary sizing of the inductor (transformer) on the bases of the design entries (specifications). It draws the inductor (transformer) layers for the specific process design kit, including vias and underpasses, with or without patterned ground shield, and launches the electromagnetic simulations, achieving effective design automation with respect to the traditional design flow for RFICs. With the present software suite the complete design time is reduced significantly (typically 1 hour on a PC based on Intel® Pentium® Dual 1.80GHz CPU with 2-GB RAM). Afterwards both the device equivalent circuit and the layout are ready to be imported in the Cadence environment

    Early appearance and possible functions of non-neuromuscular cholinesterase activities

    Get PDF
    The biological function of the cholinesterase (ChE) enzymes has been studied since the beginning of the twentieth century. Acetylcholinesterase plays a key role in the modulation of neuromuscular impulse transmission in vertebrates, while in invertebrates pseudo cholinesterases are preeminently represented. During the last 40 years, awareness of the role of ChEs role in regulating non-neuromuscular cell-to-cell interactions has been increasing such as the ones occurring during gamete interaction and embryonic development. Moreover, ChE activities are responsible for other relevant biological events, including regulation of the balance between cell proliferation and cell death, as well as the modulation of cell adhesion and cell migration. Understanding the mechanisms of the regulation of these events can help us foresee the possible impact of neurotoxic substances on the environmental and human health

    High-Resolution Radiometer for Remote Sensing of Solar Flare Activity from Low Earth Orbit Satellites

    Get PDF
    This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause.For this Article Withdrawal Statement, please click on: https://ojs.bilpublishing.com/index.php/jasr/article/view/621Abstract: Solar flares, intense bursts of radiation, can disrupt the atmosphere and potentially affect communication, navigation and electrical systems. A newly developed miniaturised microwave radiometer used on a space-borne platform should offer astronomers unprecedented understanding of the largest explosive phenomena in our solar system. In this paper the activity and results of the EU funded research project FLARES are presented. Objective of FLARES has been the study, analysis and design of millimetre-wave (mm-wave) system-on-chip (SoC) radiometer for space-borne detection of solar flares. The proposed approach has contributed to reduce significantly the power consumption and weight with respect to the existing instruments for the observation and study of solar flares. In particular, the proposed SoC Dicke radiometer can achieve one order of magnitude improvement in terms of resolution, so allowing the detection of solar flares with relatively low intensity, i.e. about 100 times lower than those currently detected by the existing systems, owing to space-borne operations and the microchip-level miniaturization through silicon technology under space qualification

    An easy 3D printing approach to manufacture vertical diffusion cells for in vitro release and permeation studies

    Get PDF
    Vertical diffusion cells are commonly used in the pharmaceutical and cosmetic fields to study the release and permeation of active ingredients through synthetic or biological membranes. Nevertheless, the commercially available glass-based systems are expensive and need to be carefully handled due to their fragility. Fused deposition modeling 3D printing is an additive manufacturing technique that allows producing objects layer by layer using different thermoplastic materials. Among them, polypropylene is a robust, flexible, and chemically inert polymer that can resist to many organic solvents. In this work, we designed and printed a vertical diffusion cell following pharmacopeia requirements by using polypropylene in a fused deposition modeling 3D printer. To keep the system thermostated, the developed model fits in a heating block to avoid the use of water recirculating system. The vertical diffusion cells were leak-free and presented chemical resistance and no interaction with model molecules (i.e., caffeine, diclofenac sodium, and glycyrrhetinic acid). The 3D printed cells were compared to commercially available glass cells and then two different types of synthetic membranes (i.e., PDMS and Strat-M®) were used to evaluate the permeation of a caffeine hydrogel. The developed 3D printed testing system could represent an efficient alternative to the glass-based equipment

    Keratin-based Nanofibres

    Get PDF
    Non

    Poly(3-hydroxybutyrate): A potential biodegradable excipient for direct 3D printing of pharmaceuticals

    Get PDF
    During the past decades, 3D printing has revolutionised different areas of research. Despite the considerable progress achieved in 3D printing of pharmaceuticals, the limited choice of suitable materials remains a challenge to overcome. The growing search for sustainable excipients has led to an increasing interest in biopolymers. Poly(3-hydroxybutyrate) (PHB) is a biocompatible and biodegradable biopolymer obtained from bacteria that could be efficiently employed in the pharmaceutical field. Here we aimed to demonstrate its potential application as a thermoplastic material for personalised medicine through 3D printing. More specifically, we processed PHB by using direct powder extrusion, a one-step additive manufacturing technique. To assess and denote the feasibility and versatility of the process, a 3D square model was manufactured in different dimensions (sidexheight: 12x2 mm; 18x2 mm; 24x2 mm) and loaded with increasing percentages of a model drug (up to 30% w/w). The manufacturing process was influenced by the drug content, and indeed, an increase in the amount of the drug determined a reduction in the printing temperature, without affecting the other parameters (such as the layer height). The composition of the model squares was investigated using Fourier-transform infrared spectroscopy, the resulting spectra confirmed that the starting materials were successfully incorporated into the final formulations. The thermal behaviour of the printed systems was characterized by differential scanning calorimetry, and thermal gravimetric analysis. Moreover, the sustained drug release profile of the formulations was performed over 21 days and showed to be dependent on the dimensions of the printed object and on the amount of loaded drug. Indeed, the formulation with 30% w/w in the dimension 24x2 mm released the highest amount of drug. Hence, the results suggested that PHB and direct powder extrusion technique could be promising tools for the manufacturing of prolonged release and personalised drug delivery forms

    Regenerated keratin membrane to match the in vitro drug diffusion through human epidermis

    Get PDF
    AbstractThis work aimed to develop membranes made of regenerated keratin and ceramides (CERs) to match the barrier property of the human stratum corneum in in vitro percutaneous absorption studies. The membrane composition was optimized on the basis of the in vitro drug diffusion profiles of ibuprofen, propranolol and testosterone chosen as model drugs on the basis of their different diffusion and solubility properties. The data were compared to those obtained using human epidermis.The ATR-FTIR and SEM analyses revealed that CERs were suspended into the regenerated keratin matrix, even if a partial solubilization occurred. It resulted in the membranes being physically stable after exposure to aqueous buffer and/or mineral oil and the fluxes of ibuprofen and propranolol from these vehicles through membranes and human skin were of the same order of magnitude. The best relationship with human epidermis data was obtained with 180μm-thick membrane containing 1% ceramide III and 1% ceramide VI. The data on the testosterone diffusion were affected by the exposure of the membrane to a water/ethanol solution over a prolonged period of time, indicating that such an organic solvent was able to modify the supermolecular organization of keratin and CERs.The keratin/CER membranes can represent a simplified model to assay the in vitro skin permeability study of small molecules

    Cholinergic Pesticides

    Get PDF
    Neurotoxicity exerted by organophosphates and carbamate
    corecore