112 research outputs found
Convolutional Autoencoder for Landmine Detection on GPR Scans
Buried unexploded landmines are a serious threat in many countries all over the World. As many landmines are nowadays mostly plastic made, the use of ground penetrating radar (GPR) systems for their detection is gaining the trend. However, despite several techniques have been proposed, a safe automatic solution is far from being at hand. In this paper, we propose a landmine detection method based on convolutional autoencoder applied to B-scans acquired with a GPR. The proposed system leverages an anomaly detection pipeline: the autoencoder learns a description of B-scans clear of landmines, and detects landmine traces as anomalies. In doing so, the autoencoder never uses data containing landmine traces at training time. This allows to avoid making strong assumptions on the kind of landmines to detect, thus paving the way to detection of novel landmine models
A new class of glycomimetic drugs to prevent free fatty acid-induced endothelial dysfunction
Background: Carbohydrates play a major role in cell signaling in many biological processes. We have developed a set of glycomimetic drugs that mimic the structure of carbohydrates and represent a novel source of therapeutics for endothelial dysfunction, a key initiating factor in cardiovascular complications. Purpose: Our objective was to determine the protective effects of small molecule glycomimetics against free fatty acidinduced endothelial dysfunction, focusing on nitric oxide (NO) and oxidative stress pathways. Methods: Four glycomimetics were synthesized by the stepwise transformation of 2,5dihydroxybenzoic acid to a range of 2,5substituted benzoic acid derivatives, incorporating the key sulfate groups to mimic the interactions of heparan sulfate. Endothelial function was assessed using acetylcholineinduced, endotheliumdependent relaxation in mouse thoracic aortic rings using wire myography. Human umbilical vein endothelial cell (HUVEC) behavior was evaluated in the presence or absence of the free fatty acid, palmitate, with or without glycomimetics (1µM). DAF2 and H2DCFDA assays were used to determine nitric oxide (NO) and reactive oxygen species (ROS) production, respectively. Lipid peroxidation colorimetric and antioxidant enzyme activity assays were also carried out. RTPCR and western blotting were utilized to measure Akt, eNOS, Nrf2, NQO1 and HO1 expression. Results: Ex vivo endotheliumdependent relaxation was significantly improved by the glycomimetics under palmitateinduced oxidative stress. In vitro studies showed that the glycomimetics protected HUVECs against the palmitateinduced oxidative stress and enhanced NO production. We demonstrate that the protective effects of preincubation with glycomimetics occurred via upregulation of Akt/eNOS signaling, activation of the Nrf2/ARE pathway, and suppression of ROSinduced lipid peroxidation. Conclusion: We have developed a novel set of small molecule glycomimetics that protect against free fatty acidinduced endothelial dysfunction and thus, represent a new category of therapeutic drugs to target endothelial damage, the first line of defense against cardiovascular disease
Lessons from non-canonical splicing
Recent improvements in experimental and computational techniques that are used to study the transcriptome have enabled an unprecedented view of RNA processing, revealing many previously unknown non-canonical splicing events. This includes cryptic events located far from the currently annotated exons and unconventional splicing mechanisms that have important roles in regulating gene expression. These non-canonical splicing events are a major source of newly emerging transcripts during evolution, especially when they involve sequences derived from transposable elements. They are therefore under precise regulation and quality control, which minimizes their potential to disrupt gene expression. We explain how non-canonical splicing can lead to aberrant transcripts that cause many diseases, and also how it can be exploited for new therapeutic strategies
Indagini non distruttive per la diagnostica delle vie d’acqua in esercizio. Possibili sviluppi sperimentali con tecniche di telerilevamento da aereo e georadar.
L’importanza della risorsa acqua richiede reti di distribuzione sempre più efficienti e moderne per garantirne un utilizzo razionale. Le condizioni operative attuali impongono spesso di realizzare la manutenzione dei canali irrigui in condizioni di esercizio o di realizzare interventi in periodi durante i quali non è possibile interrompere l’erogazione: in queste condizioni la diagnostica delle reti irrigue assume sempre più importanza per garantire un servizio continuo. Le indagini diagnostiche non distruttive si presentano come gli strumenti più idonei per raggiungere questo scopo: in particolare le tecniche di Telerilevamento iperspettrale e di termografia (da aereo e da terra) e le prospezioni Georadar. L’unicità di queste metodologie risiede nel fatto che le misure non sono di tipo puntuale ma distribuite nello spazio (areali) e, inoltre, hanno un utilizzo polivalente. Alla luce di queste considerazioni, ci si propone di analizzare i limiti, le potenzialità e la complementarietà delle due tecniche d’indagine, rispetto alle diverse condizioni ambientali nelle quali ci si trova a operare e al grado di risoluzione richiesto dal problema. Scopo di questa analisi è la valutazione della fattibilità di un sistema integrato di diagnostica non distruttiva dei canali irrigui, che ne permetta un uso estensivo su lunghe tratte di canali
Sviluppi sperimentali con tecniche di prospezione georadar e telerilevamento iperspettrale da aereo per la diagnostica non distruttiva delle vie d’acqua.
L’importanza della risorsa acqua richiede reti di distribuzione sempre più efficienti e moderne per garantirne un utilizzo razionale. Le condizioni operative attuali impongono spesso di realizzarne la manutenzione in condizioni di esercizio o di realizzare interventi in periodi durante i quali non è possibile interrompere l’erogazione e in queste condizioni la diagnostica dei canali assume sempre più importanza per garantire un servizio continuo. Le indagini diagnostiche non distruttive si presentano come gli strumenti più idonei per raggiungere questo scopo; in particolare le prospezioni Georadar e le tecniche di Telerilevamento iperspettrale da aereo. L’unicità di queste metodologie risiede nel fatto che le misure non sono di tipo puntuale, ma distribuite nello spazio (areali) e questo ne permette un uso estensivo su lunghe tratte di canali. Alla luce di queste considerazioni, ci si propone di analizzare i limiti, le potenzialità e la complementarietà delle due metodologie d’indagine, rispetto alle diverse condizioni ambientali nelle quali ci si trova a operare e al grado di risoluzione richiesto dal problema, presentando due esempi applicativi di queste tecniche d’indagine
Design of cobalt nanoparticles with tailored structural and morphological properties via O/W and W/O microemulsions and their deposition onto silica
© 2015 by the authors Cobalt nanostructures with different size and morphology, i.e., spherical nanoparticles, nanorods, and particles arranged into elongated structures, were prepared using micelles and microemulsions as confined reaction media. The syntheses were carried out using three types of systems: aqueous surfactant solutions, oil-in water (O/W), and water-in-oil (W/O) microemulsions. The influence of the surfactant and the precipitating agent used for synthesis was also investigated. For this purpose, cobalt nanostructures were prepared using different non-ionic surfactants, namely Synperonic® 10/6, Pluronic® P123 10.3390/catal5010442 and a mixture of SPAN 20–TWEEN 80. Three different precipitating agents were used: sodium borohydride, sodium hydroxide, and oxalic acid. Our findings revealed that by changing the type of reaction media as well as the precipitating agent it is possible to modify the shape and size of the cobalt nanostructures. Moreover, the use of O/W microemulsion generates better results in terms of colloidal stability and uniformity of particle size with respect to W/O microemulsion. The different cobalt nanostructures were supported on commercial and mesoporous silica; transmission electron microscopy (TEM) images showed that after deposition the Co nanocrystals remain well dispersed on the silica supports. This behavior suggests their great potential in catalytic applications
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