259 research outputs found

    The influence of graphitization catalyst electrode in electrical discharge machining of polycrystalline diamond-finishing condition

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    Electrical Discharge Machining (EDM) is a non-contact machining process that becomes famous in machining of Polycrystalline Diamond (PCD). The material is typically used as the cutting tools for aerospace and automotive industries. However, low electrical conductivity and high melting temperature of PCD has caused slower EDM process. This investigation purposely designed to investigate the influence of different types of electrode which are Copper (ordinary electrode) and Copper-Nickel (newly proposed graphitization catalyst electrode) on EDM performance of MRR and Ra. Interestingly the newly proposed electrode gave positive impact to the investigated performance indication. Cu-Ni electrode recorded 35% better in MRR than the Cu electrode, though with higher short-circuiting rate. Cu-Ni also provided the lowest Ra value with 10% better than the best Ra produced by Cu electrode. This phenomenon occurred as due to the high interaction between the catalyst materials of nickel and diamond which supported by the qualification data provided in this investigation

    leveraging artificial intelligence to improve voice disorder identification through the use of a reliable mobile app

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    The evolution of the Internet of Things, cloud computing and wireless communication has contributed to an advance in the interconnectivity, efficiency and data accessibility in smart cities, improving environmental sustainability, quality of life and well-being, knowledge and intellectual capital. In this scenario, the satisfaction of security and privacy requirements to preserve data integrity, confidentiality and authentication is of fundamental importance. In particular, this is essential in the healthcare sector, where health-related data are considered sensitive information able to reveal confidential details about the subject. In this regard, to limit the possibility of security attacks or privacy violations, we present a reliable mobile voice disorder detection system capable of distinguishing between healthy and pathological voices by using a machine learning algorithm. This latter is totally embedded in the mobile application, so it is able to classify the voice without the necessity of transmitting user data to or storing user data on any server. A Boosted Trees algorithm was used as the classifier, opportunely trained and validated on a dataset composed of 2003 voices. The most frequently considered acoustic parameters constituted the inputs of the classifier, estimated and analyzed in real time by the mobile application

    Dysphonia Detection Index (DDI): A New Multi-Parametric Marker to Evaluate Voice Quality

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    The rapid diffusion of voice disorders and the lack of appropriate knowledge about the problem have prompted the search for novel and reliable approaches to detect dysphonia, through easy and accessible instruments such as mobile devices. These systems represent, in fact, valid instruments to improve the patient care not only to facilitate the monitoring of symptoms of any diseases but also supporting the correct diagnosis of pathology, such as the dysphonia. In this paper, we propose a new marker, namely the dysphonia detection index, able to support the evaluation of voice disorders, which can be embedded in a mobile health solution. Four acoustic parameters are combined in a single marker to globally evaluate the state of the health of the voice and to assess the presence or not of a voice disorder. A model tree regression algorithm has been applied to define the relationship between these parameters, and the Youden analysis has been used to define the threshold value to distinguish a pathological from a healthy voice. The reliability of the proposed index has been tested in terms of correct classification of accuracy, sensitivity, and specificity. A dataset of 2003 voices has been used to evaluate the performance of our proposed index, composed of samples selected from three different databases: the Massachusetts Eye and Ear Infirmary, the Saarbruecken Voice, and the VOice ICar fEDerico II databases. Our approach achieved the best performances in comparison with other algorithms, and accuracy equals to 82.2%, while sensitivity and specificity are 82% and 82.6%, respectively

    The Subtype of GluN2 C-terminal Domain Determines the Response to Excitotoxic Insults

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    It is currently unclear whether the GluN2 subtype influences NMDA receptor (NMDAR) excitotoxicity. We report that the toxicity of NMDAR-mediated Ca(2+) influx is differentially controlled by the cytoplasmic C-terminal domains of GluN2B (CTD(2B)) and GluN2A (CTD(2A)). Studying the effects of acute expression of GluN2A/2B-based chimeric subunits with reciprocal exchanges of their CTDs revealed that CTD(2B) enhances NMDAR toxicity, compared to CTD(2A). Furthermore, the vulnerability of forebrain neurons in vitro and in vivo to NMDAR-dependent Ca(2+) influx is lowered by replacing the CTD of GluN2B with that of GluN2A by targeted exon exchange in a mouse knockin model. Mechanistically, CTD(2B) exhibits stronger physical/functional coupling to the PSD-95-nNOS pathway, which suppresses protective CREB activation. Dependence of NMDAR excitotoxicity on the GluN2 CTD subtype can be overcome by inducing high levels of NMDAR activity. Thus, the identity (2A versus 2B) of the GluN2 CTD controls the toxicity dose-response to episodes of NMDAR activity

    Role of Interventional Radiology in Management of Gastrointestinal Bleeding

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    Gastrointestinal bleeding is a common and potentially life-threatening condition that requires prompt and effective management. Interventional radiology has emerged as a valuable tool in the management of gastrointestinal bleeding, offering minimally invasive techniques that can rapidly control bleeding and improve patient outcomes. This review aims to provide an overview of the role of interventional radiology in the management of gastrointestinal bleeding, including its various techniques and their efficacy. The review discusses the different interventional radiology procedures that can be used to diagnose and treat gastrointestinal bleeding. It also highlights the advantages of techniques used in evaluation and management, including their ability to localize and control bleeding, as well as their low complication rates and shorter recovery times compared to traditional surgical approaches. Furthermore, the review addresses the specific indications for interventional radiology in the management of gastrointestinal bleeding, as well as the role of interventional radiology in the setting of underlying conditions. Overall, this review provides a comprehensive overview of the role of interventional radiology in the management of gastrointestinal bleeding, highlighting its effectiveness and potential benefits for patients. It also emphasizes the need for further research and collaboration between interventional radiologists and gastroenterologists to optimize the use of these techniques in clinical practice

    Islamism and the state after the Arab uprisings: Between people power and state power

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    The authors would like to thank the Arts and Humanities Research Council for facilitating the research for this article through their support of the research network People Power versus State Power of the Centre for the Advanced Study of the Arab World.This paper examines the trajectories of different Islamist trends in the light of the Arab uprisings. It proposes a distinction between statist and non-statist Islamism to help understand the multiplicity of interactions between Islamists and the state, particularly after 2011. It is outlined how statist Islamists (Islamist parties principally) can contribute to the stabilization and democratization of the state when their interactions with other social and political actors facilitate consensus building in national politics. By contrast when these interactions are conflictual, it has a detrimental impact on both the statist Islamists, and the possibility of democratic politics at the national level. Non statist-Islamists (from quietist salafi to armed jihadi) who prioritize the religious community over national politics are directly impacted by the interactions between statist Islamists and the state, and generally tend to benefit from the failure to build a consensus over democratic national politics. Far more than nationally-grounded statist Islamists, non-statist Islamists shape and are shaped by the regional dynamics on the Arab uprisings and the international and transnational relations between the different countries and conflict areas of the Middle East. The Arab uprisings and their aftermath reshaped pre-existing national and international dynamics of confrontation and collaboration between Islamists and the state, and between statist and non-statists Islamists, for better (Tunisia) and for worse (Egypt).PostprintPeer reviewe

    Inhibition of TXNIP expression in vivo blocks early pathologies of diabetic retinopathy

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    Evidence is mounting that proinflammatory and proapoptotic thioredoxin-interacting protein (TXNIP) has a causative role in the development of diabetes. However, there are no studies investigating the role of TXNIP in diabetic retinopathy (DR). Here, we show that, in diabetic rats, TXNIP expression and hexosamine biosynthesis pathway (HBP) flux, which regulates TXNIP, are elevated in the retina and correlates well with the induction of inflammatory cyclooxygenase 2 (Cox-2) and sclerotic fibronectin (FN). We blocked the expression of TXNIP in diabetic rat retinas by: (i) inhibiting HBP flux; (ii) inducing post-transcriptional gene silencing (PTGS) for TXNIP mRNA; and (iii) performing an in vivo transcriptional gene silencing (TGS) approach for TXNIP knockdown by promoter-targeted small interfering RNAs and cell-penetrating peptides as RNA interference (RNAi) transducers. Each of these methods is efficient in downregulating TXNIP expression, resulting in blockade of its target genes, Cox-2 and FN, demonstrating that TXNIP has a causative role in aberrant gene induction in early DR. RNAi TGS of TXNIP abolishes diabetes-induced retinal gliosis and ganglion injury. Thus, TXNIP has a critical role in inflammation and retinal injury in early stages of DR. The successful employment of TXNIP TGS and amelioration of its pathological effects open the way for novel therapeutic strategies aimed to block disease onset and progression of DR

    Fabrication and in vitro deployment of a laser-activated shape memory polymer vascular stent

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    <p>Abstract</p> <p>Background</p> <p>Vascular stents are small tubular scaffolds used in the treatment of arterial stenosis (narrowing of the vessel). Most vascular stents are metallic and are deployed either by balloon expansion or by self-expansion. A shape memory polymer (SMP) stent may enhance flexibility, compliance, and drug elution compared to its current metallic counterparts. The purpose of this study was to describe the fabrication of a laser-activated SMP stent and demonstrate photothermal expansion of the stent in an <it>in vitro </it>artery model.</p> <p>Methods</p> <p>A novel SMP stent was fabricated from thermoplastic polyurethane. A solid SMP tube formed by dip coating a stainless steel pin was laser-etched to create the mesh pattern of the finished stent. The stent was crimped over a fiber-optic cylindrical light diffuser coupled to an infrared diode laser. Photothermal actuation of the stent was performed in a water-filled mock artery.</p> <p>Results</p> <p>At a physiological flow rate, the stent did not fully expand at the maximum laser power (8.6 W) due to convective cooling. However, under zero flow, simulating the technique of endovascular flow occlusion, complete laser actuation was achieved in the mock artery at a laser power of ~8 W.</p> <p>Conclusion</p> <p>We have shown the design and fabrication of an SMP stent and a means of light delivery for photothermal actuation. Though further studies are required to optimize the device and assess thermal tissue damage, photothermal actuation of the SMP stent was demonstrated.</p
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