285 research outputs found

    The potential of Antheraea pernyi silk for spinal cord repair

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    This work was supported by the Institute of Medical Sciences of the University of Aberdeen, Scottish Rugby Union and RS McDonald Charitable Trust. We are grateful to Mr Nicholas Hawkins from Oxford University and Ms Annette Raffan from the University of Aberdeen for assistance with tensile testing. We thank Ms Michelle Gniβ for her help with the microglial response experiments. We also thank Mr Gianluca Limodio for assisting with the MATLAB script for automation of tensile testing’s data analysis.Peer reviewedPublisher PD

    Hacia un modelo de análisis de políticas públicas operativ : Un enfoque basado en los actores, sus recursos y las instituciones

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    Towards an operative analysis of public policies: An approach focused on actors, resources and institutions. This article develops an analytical model which is centred on the individual and collective behaviour of actors involved during different stages of public policy. We postulate that the content and institutional characteristics of public action (dependent variable) are the result of interactions between political-administrative authorities, on the one hand, and, on the other, social groups which cause or suffer the negative effects of a collective problem which public action attempts to resolve (independent variables). The 'game' of the actors depends not only on their particular interests, but also on their resources (money, time, consensus, organization, rights, infrastructure, information, personnel, strength, political support) which they are able to exploit to defend their positions, as well as on the institutional rules which frame these policy games

    Laser pulse effects on plasma-sprayed and bulk tungsten

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    Tungsten (W) is considered a promising plasma-facing material for protecting the divertor of the ITER (International Thermonuclear Experimental Reactor). The effects on W of transient thermal loads of high energy occurring in a tokamak under operative conditions have been simulated through a single laser pulse delivered by an Nd:YAG laser. Bulk and plasma-sprayed (PS) samples have been submitted to tests and successively examined via SEM (scanning electron microscopy) observations. In both types of materials, the laser pulse induces similar effects: (i) a crater forms in the spot central area; (ii) all around the area, the ejection and the movement of molten metal give rise to a ridge; (iii) in a more external area, the surface shows plates with jagged boundaries and cracks induced by thermal stresses; (iv) the pores present in the original material become preferred ablation sites. However, the affected surface area in PS samples is larger and asymmetric if compared to that of bulk material. Such a difference has been explained by considering how microstructural characteristics influence heat propagation from the irradiated spot, and it was found that grain size and shape play a decisive role

    Study of 13CR-4NI-(MO) (F6NM) steel grade heat treatment for maximum hardness control in industrial heats

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    The standard NACE MR0175 (ISO 15156) requires a maximum hardness value of 23 HRC for 13Cr-4Ni-(Mo) steel grade for sour service, requiring a double tempering heat treatment at temperature in the range 648–691°C for the first tempering and 593–621°C for the second tempering. Difficulties in limiting alloy hardness after the tempering of forged mechanical components (F6NM) are often faced. Variables affecting the thermal behavior of 13Cr-4Ni-(Mo) during single and double tempering treatments have been studied by means of transmission electron microscopy (TEM) observations, X-ray diffraction measurements, dilatometry, and thermo-mechanical simulations. It has been found that relatively low Ac1 temperatures in this alloy induce the formation of austenite phase above 600°C during tempering, and that the formed, reverted austenite tends to be unstable upon cooling, thus contributing to the increase of final hardness via transformation to virgin martensite. Therefore, it is necessary to increase the Ac1 temperature as much as possible to allow the tempering of martensite at the temperature range required by NACE without the detrimental formation of virgin martensite upon final cooling. Attempts to do so have been carried out by reducing both carbon (<0.02% C) and nitrogen (<100 ppm) levels. Results obtained herein show final hardness below NACE limits without an unacceptable loss of mechanical strength

    Treating Policy Brokers Seriously: Evidence from the Climate Policy

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    New record in the Hawaiian Islands of Orasema minutissima (Hymenoptera: Eucharitidae), an ant-parasitic wasp and a potential biocontrol agent against the Little Fire Ant, Wasmannia auropunctata (Hymenoptera: Formicidae)

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    Orasema minutissima Howard (Hymenoptera: Eucharitidae) is recorded fromthe Hawaiian Islands for the first time. It has been established on the island of Hawai?isince at least 2019. The wasp is a parasitoid of the immature stages of Pheidole andWasmannia (Formicidae: Myrmicinae), both of which are significant pests on several ofthe Hawaiian Islands. Already found in substantial numbers, the wasp is a potential biological control agent for Wasmannia auropunctata, the Little Fire Ant.Fil: Heraty, John Michael. University of California; Estados UnidosFil: Rogers, Valle D.. University of California; Estados UnidosFil: Johnson, M. Tracy. Institute of Pacific Islands Forestry; Estados UnidosFil: Perreira, Williams D.. No especifíca;Fil: Baker, Austin J.. University of California; Estados UnidosFil: Bitume, Ellyn. Institute of Pacific Islands Forestry; Estados UnidosFil: Murray, Elizabeth. Washington State University; Estados UnidosFil: Varone, Laura. Fundación para el Estudio de Especies Invasivas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Effect of powder recycling on inclusion content and distribution in AISI 316L produced by L-PBF technique

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    AISI 316 L stainless steel is widely used as material to produce components by means of additive manufacturing. To increase the circular economy, the powders are collected and re-used after the printing process, thus the effect of powder recycling on microstructure and properties of printed components is of the utmost importance. This work focused the attention on non-metallic inclusions by examining virgin and recycled powders, and products printed by using both types of powders in a laser powder bed fusion (L-PBF) process. Recycled powders exhibit an irregular shape due to fragmentation, spatters and satellites and, compared to the virgin ones, have a higher gas (O, H and C) content. Both powders contain non-metallic inclusions with a larger quantity in the recycled ones. The printed samples have a similar microstructure, however those produced by using recycled powders exhibit voids of larger size and a little greater amount of inclusions. XRD and EDS examinations of inclusions extracted from the metallic matrix showed that they consist of a mix of amorphous and crystalline silica. Large part of these particles are already present in virgin powders and only a minor part forms during repeated printing operations. Accordingly, the quality of virgin powders is the factor that mainly affects the inclusion content of printed products indicating that the powder production process is the most critical stage of the whole manufacturing process

    The first case of acinic cell carcinoma of the breast within a fibroadenoma: Case report

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    AbstractA case of acinic cell carcinoma of the breast is reported in a 26-year-old woman. She presented a lump in her right breast, that seemed to be a fibroadenoma. The open biopsy revealed a well-bordered fibroadenoma, together with a proliferation of cells characterized by serous acinar differentiation and eosinophilic cytoplasmic granules. Tumor cells stained for amylase, lysozyme, α-1-antichymotripsin, epithelial membrane antigen, S-100 protein, pan-cytokeratin, cytokeratin 7 and E-cadherin. Estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 overexpression, CD10, P63, smooth muscle actin, cytokeratin 5/6 were negative. The sentinel node was negative. 8 months after surgery she is in good clinical conditions without recurrence or metastases

    Patient-reported outcomes and patient-reported outcome measures in interstitial lung disease: Where to go from here?

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    Patient-reported outcome measures (PROMs), tools to assess patient self-report of health status, are now increasingly used in research, care and policymaking. While there are two well-developed disease-specific PROMs for interstitial lung diseases (ILD) and idiopathic pulmonary fibrosis (IPF), many unmet and urgent needs remain. In December 2019, 64 international ILD experts convened in Erice, Italy to deliberate on many topics, including PROMs in ILD. This review summarises the history of PROMs in ILD, shortcomings of the existing tools, challenges of development, validation and implementation of their use in clinical trials, and the discussion held during the meeting. Development of disease-specific PROMs for ILD including IPF with robust methodology and validation in concordance with guidance from regulatory authorities have increased user confidence in PROMs. Minimal clinically important difference for bidirectional changes may need to be developed. Cross-cultural validation and linguistic adaptations are necessary in addition to robust psychometric properties for effective PROM use in multinational clinical trials. PROM burden of use should be reduced through appropriate use of digital technologies and computerised adaptive testing. Active patient engagement in all stages from development, testing, choosing and implementation of PROMs can help improve probability of success and further growth

    Artificial Neural Network-based Model Used to Determine Citric Maturity Level

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    One of the most important tasks in price determination of a product is the classification for its quality, color, maturity, etc. Usually vegetables and fruits are classified manually. This process is complex and usually some errors in the product categorization occur due to the subjectivity of persons with limited skills and long hours’ work. A possible alternative is the automatic selection of products using classifiers based on computer vision systems. These systems capture the image of the product and determine its class in real time. In this paper a model capable of establishing the level of maturity of oranges, using artificial neural networks, is proposed.Sociedad Argentina de Informática e Investigación Operativ
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