31 research outputs found

    Human Cryptic Host Defence Peptide GVF27 Exhibits Anti-Infective Properties against Biofilm Forming Members of the Burkholderia cepacia Complex

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    Therapeutic solutions to counter Burkholderia cepacia complex (Bcc) bacteria are challenging due to their intrinsically high level of antibiotic resistance. Bcc organisms display a variety of potential virulence factors, have a distinct lipopolysaccharide naturally implicated in antimicrobial resistance. and are able to form biofilms, which may further protect them from both host defence peptides (HDPs) and antibiotics. Here, we report the promising anti-biofilm and immunomodulatory activities of human HDP GVF27 on two of the most clinically relevant Bcc members, Burkholderia multivorans and Burkholderia cenocepacia. The effects of synthetic and labelled GVF27 were tested on B. cenocepacia and B. multivorans biofilms, at three different stages of formation, by confocal laser scanning microscopy (CLSM). Assays on bacterial cultures and on human monocytes challenged with B. cenocepacia LPS were also performed. GVF27 exerts, at different stages of formation, anti-biofilm effects towards both Bcc strains, a significant propensity to function in combination with ciprofloxacin, a relevant affinity for LPSs isolated from B. cenocepacia as well as a good propensity to mitigate the release of pro-inflammatory cytokines in human cells pre-treated with the same endotoxin. Overall, all these findings contribute to the elucidation of the main features that a good therapeutic agent directed against these extremely leathery biofilm-forming bacteria should possess

    Cytotoxicity of an innovative pressurised cyclic solid–liquid (Pcsl) extract from artemisia annua

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    Therapeutic treatments with Artemisia annua have a long-established tradition in various diseases due to its antibacterial, antioxidant, antiviral, anti-malaria and anti-cancer effects. However, in relation to the latter, virtually all reports focused on toxic effects of A. annua extracts were obtained mostly through conventional maceration methods. In the present study, an innovative extraction procedure from A. annua, based on pressurised cyclic solid–liquid (PCSL) extraction, resulted in the production of a new phytocomplex with enhanced anti-cancer properties. This extraction procedure generated a pressure gradient due to compressions and following decompressions, allowing to directly perform the extraction without any maceration. The toxic effects of A. annua PCSL extract were tested on different cells, including three cancer cell lines. The results of this study clearly indicate that the exposure of human, murine and canine cancer cells to serial dilutions of PCSL extract resulted in higher toxicity and stronger propensity to induce apoptosis than that detected by subjecting the same cells to Artemisia extracts obtained through canonical extraction by maceration. Collected data suggest that PCSL extract of A. annua could be a promising and economic new therapeutic tool to treat human and animal tumours

    Address-event imagers for sensor networks: evaluation and modeling

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    Focal-Plane Change Triggered Video Compression for Low-Power Vision Sensor Systems

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    Video sensors with embedded compression offer significant energy savings in transmission but incur energy losses in the complexity of the encoder. Energy efficient video compression architectures for CMOS image sensors with focal-plane change detection are presented and analyzed. The compression architectures use pixel-level computational circuits to minimize energy usage by selectively processing only pixels which generate significant temporal intensity changes. Using the temporal intensity change detection to gate the operation of a differential DCT based encoder achieves nearly identical image quality to traditional systems (4dB decrease in PSNR) while reducing the amount of data that is processed by 67% and reducing overall power consumption reduction of 51%. These typical energy savings, resulting from the sparsity of motion activity in the visual scene, demonstrate the utility of focal-plane change triggered compression to surveillance vision systems

    An address-event fall detector for assisted living applications

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    In this paper, we describe an address-event vision system designed to detect accidental falls in elderly home care applications. The system raises an alarm when a fall hazard is detected. We use an asynchronous temporal contrast vision sensor which features sub-millisecond temporal resolution. The sensor reports a fall at ten times higher temporal resolution than a frame-based camera and shows 84% higher bandwidth efficiency as it transmits fall events. A lightweight algorithm computes an instantaneous motion vector and reports fall events. We are able to distinguish fall events from normal human behavior, such as walking, crouching down, and sitting down. Our system is robust to the monitored person's spatial position in a room and presence of pets

    Continual reinforcement learning in 3D non-stationary environments

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    High-dimensional always-changing environments constitute a hard challenge for current reinforcement learning techniques. Artificial agents, nowadays, are often trained off-line in very static and controlled conditions in simulation such that training observations can be thought as sampled i.i.d. from the entire observations space. However, in real world settings, the environment is often non-stationary and subject to unpredictable, frequent changes. In this paper we propose and openly release CRLMaze, a new benchmark for learning continually through reinforcement in a complex 3D non-stationary task based on ViZDoom and subject to several environmental changes. Then, we introduce an end-to-end model-free continual reinforcement learning strategy showing competitive results with respect to four different baselines and not requiring any access to additional supervised signals, previously encountered environmental conditions or observations

    A 100 Microwatt Ultra Low-Power Contrast-Based Asynchronous Vision Sensor

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    Ribotoxin-like proteins from Boletus edulis: structural properties, cytotoxicity and in vitro digestibility

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    Porcini are edible mushrooms widely used in cooking due to their extraordinary taste. Despite this, cases of food poisoning have been reported in the recent literature also for ingestion of porcini. Here, we report the isolation from Boletus edulis fruiting bodies of two novel ribotoxin-like proteins (RL-Ps), enzymes already studied in other organisms for their toxicity. These RL-Ps, named Edulitin 1 (16-kDa) and Edulitin 2 (14-kDa), show peculiar structural and enzymatic differences, which probably reflect their different bio-activities and a dose/time dependent toxicity (Edulitin 2) on normal and tumoral human cells. Particularly interesting is the resistance to proteolysis of Edulitin 2, for which it was observed that its toxicity was abolished only after heat treatment (90 °C) followed by proteolysis. As mushroom poisoning is a serious food safety issue, data here presented confirm the existence of toxins also in porcini and the importance of a proper cooking before their consumption
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