The role of viral and bacterial infections in the pathogenesis of IPF: a systematic review and meta-analysis

Background: Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease. Several risk factors such as smoking, air pollution, inhaled toxins, high body mass index and infectious agents are involved in the pathogenesis of IPF. In the present study, this meta-analysis study investigates the prevalence of viral and bacterial infections in the IPF patients and any possible association between these infections with pathogenesis of IPF. Methods: The authors carried out this systematic literature review from different reliable databases such as PubMed, ISI Web of Science, Scopus and Google Scholar to December 2020.Keywords used were the following �Idiopathic pulmonary fibrosis�, �Infection�, �Bacterial Infection� and �Viral Infection�, alone or combined together with the Boolean operators "OR�, �AND� and �NOT� in the Title/Abstract/Keywords field. Pooled proportion and its 95 CI were used to assess the prevalence of viral and bacterial infections in the IPF patients. Results: In this systematic review and meta-analyses, 32 studies were selected based on the exclusion/inclusion criteria. Geographical distribution of included studies was: eight studies in American people, 8; in European people, 15 in Asians, and one in Africans. The pooled prevalence for viral and bacterial infections w ere 53.72 (95 CI 38.1�69.1) and 31.21 (95 CI 19.9�43.7), respectively. The highest and lowest prevalence of viral infections was HSV (77.7 95 CI 38.48�99.32), EBV (72.02, 95 CI 44.65�90.79) and Influenza A (7.3, 95 CI 2.66�42.45), respectively. Whereas the highest and lowest prevalence in bacterial infections were related to Streptococcus sp. (99.49, 95 CI 96.44�99.9) and Raoultella (1.2, 95 CI 0.2�3.08), respectively. Conclusions: The results of this review were confirmed that the presence of viral and bacterial infections are the risk factors in the pathogenesis of IPF. In further analyses, which have never been shown in the previous studies, we revealed the geographic variations in the association strengths and emphasized other methodological parameters (e.g., detection method). Also, our study supports the hypothesis that respiratory infection could play a key role in the pathogenesis of IP. © 2021, The Author(s)

Mechanical Properties and Microstructural Characterization of Aged Nickel-based Alloy 625 Weld Metal

The aim of this work was to evaluate the different phases formed during solidification and after thermal aging of the as-welded 625 nickel-based alloy, as well as the influence of microstructural changes on the mechanical properties. The experiments addressed aging temperatures of 650 and 950 A degrees C for 10, 100, and 200 hours. The samples were analyzed by electron microscopy, microanalysis, and X-ray diffraction in order to identify the secondary phases. Mechanical tests such as hardness, microhardness, and Charpy-V impact test were performed. Nondestructive ultrasonic inspection was also conducted to correlate the acquired signals with mechanical and microstructural properties. The results show that the alloy under study experienced microstructural changes when aged at 650 A degrees C. The aging was responsible by the dissolution of the Laves phase formed during the solidification and the appearance of gamma aEuro(3) phase within interdendritic region and fine carbides along the solidification grain boundaries. However, when it was aged at 950 A degrees C, the Laves phase was continuously dissolved and the excess Nb caused the precipitation of the delta-phase (Ni3Nb), which was intensified at 10 hours of aging, with subsequent dissolution for longer periods such as 200 hours. Even when subjected to significant microstructural changes, the mechanical properties, especially toughness, were not sensitive to the dissolution and/or precipitation of the secondary phases

Future of additive manufacturing: Overview of 4D and 3D printed smart and advanced materials and their applications

© 2020 Elsevier B.V. 4D printing is an emerging field in additive manufacturing of time responsive programmable materials. The combination of 3D printing technologies with materials that can transform and possess shape memory and self-healing capabilities means the potential to manufacture dynamic structures readily for a myriad of applications. The benefits of using multifunctional materials in 4D printing create opportunities for solutions in demanding environments including outer space, and extreme weather conditions where human intervention is not possible. The current progress of 4D printable smart materials and their stimuli-responsive capabilities are overviewed in this paper, including the discussion of shape-memory materials, metamaterials, and self-healing materials and their responses to thermal, pH, moisture, light, magnetic and electrical exposures. Potential applications of such systems have been explored to include advancements in health monitoring, electrical devices, deployable structures, soft robotics and tuneable metamaterials

Hybrid Fire Testing for Performance Evaluation of Structures in Fire - Part 2: Application

A hybrid fire testing (HFT) approach was carried out by means of both computer simulation and experimentation using the National Research Council Canada?s (NRC) testing facilities in Ottawa. Fire structural performance of a 3D full-scale 6-storey building structure was tested for a fire compartment scenario in the main floor of the building. The column in the designated fire compartment was exposed to the fire in a column furnace and the rest of the building was simulated using a numerical modeling. The methodology of the HFT and its numerical verifications were developed and described in a previous report. This report includes application of the HFT and its displacement results for fire structural performance of the whole 6-storey building. It also includes results of a separate column tested in fire using the traditional fire resistance standard test method. The second column specimen was identical to that of the column tested using the HFT. A comparison is provided between the results of the standard test and the HFT.Une d\ue9marche d?essai de r\ue9sistance au feu hybride (ERFH) a \ue9t\ue9 r\ue9alis\ue9e, par simulation par ordinateur et parall\ue8lement par exp\ue9rimentation aux installations d?essai du Conseil national de recherches du Canada (CNRC), \ue0 Ottawa. La performance structurale au feu d?une structure de b\ue2timent de six (6) \ue9tages en vraie grandeur en 3 dimensions (3D) a \ue9t\ue9 mise \ue0 l?essai pour un sc\ue9nario d?incendie en compartiment \ue0 l?\ue9preuve du feu, au niveau principal du b\ue2timent. La colonne dans le compartiment \ue0 l?\ue9preuve du feu d\ue9sign\ue9 a \ue9t\ue9 expos\ue9e au feu dans un four \ue0 colonnes, et le reste du b\ue2timent a \ue9t\ue9 simul\ue9 par mod\ue9lisation num\ue9rique. La m\ue9thodologie de l?ERFH et ses v\ue9rifications num\ue9riques ont \ue9t\ue9 mises au point et d\ue9crites dans un rapport ant\ue9rieur. Ce rapport comprend l?application de l?ERFH et ses r\ue9sultats li\ue9s au d\ue9placement pour ce qui est de la performance structurale au feu du b\ue2timent en entier. Il comprend \ue9galement les r\ue9sultats d?un essai de tenue au feu men\ue9 sur une colonne s\ue9par\ue9e au moyen de la m\ue9thode d?essai de r\ue9sistance au feu traditionnelle standard. Le deuxi\ue8me sp\ue9cimen de colonne \ue9tait identique \ue0 celui de la colonne mise \ue0 l?essai selon l?ERFH. Enfin, on \ue9tablit une comparaison entre les r\ue9sultats de l?essai standard et ceux de l?ERFH.Peer reviewed: NoNRC publication: Ye

A low-overhead localized target coverage algorithm in wireless sensor networks

International audienceThe scope of this paper is to present a low-overhead localized algorithm for the target coverage problem in wireless sensor networks. The algorithm divides the sensors into active and sleep mode nodes in order to conserve energy and extend the network lifetime. The set of active mode nodes provide full coverage to a set of targets (points) in the field. The decision of which sensors will remain active at any time is locally taken by the nodes by exchanging messages with each other. This kind of messages add overhead in the network, while high overhead can dramatically decrease the network lifetime especially in case of high node density environments. To tackle this problem we propose two variations of a localized algorithm with low communication complexity. Finally, the operational effectiveness of the proposed approaches is evaluated through simulation, while their superiority against other relevant proposed solutions in the literature is illustrated. The results show a great improvement in terms of communication cost while achieving an adequate network lifetime