1,173 research outputs found

    experimental characterization of the 3d linear viscoelastic behavior of cold recycled bitumen emulsion mixtures

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    Cold mixtures with bitumen emulsion are produced at ambient temperature, leading to substantial reductions of energy consumption and atmospheric emissions. In cold recycling applications, cement is normally used to improve the mixture performance. Thus, the rheological behavior of cold recycled mixtures is different from that of conventional hot mixtures because it is due to the interaction of fresh bitumen, aged bitumen and cementitious bonds. In this study, we investigated the three-dimensional (3D) linear viscoelastic (LVE) behavior of a cement-bitumen treated material (CBTM) mixture fabricated using bitumen emulsion and cement. For comparison, we also investigated the 3D LVE behavior of hot-mix asphalt containing 25% of reclaimed asphalt and fabricated using polymer-modified binder. Sinusoidal axial tests on cylindrical specimens, were carried out at various temperatures (from 0 °C to 50 °C) and frequencies (from 0.1 to 12 Hz). The complex Young's modulus E∗ and the complex Poisson's ratio v∗ were determined through the measurement of axial and transverse strain. We show that when considering E∗, CBTM mixtures may be considered thermo-rheologically simple and the Huet-Sayegh model can be used to simulate the frequency–temperature dependence. On the other hand, when considering v∗ the behavior of CBTM mixtures is very different from that of hot mix asphalt. In particular, its absolute value is almost constant and very close to 0.15. Keywords: Bitumen emulsion, Cold recycling, Complex modulus, Complex Poisson's ratio, Huet-Sayegh mode

    Pulmonary artery thrombosis in home patient with a mild COVID-19 disease

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    Abstract COVID-19 has been described as the cause for a proinflammatory and hypercoagulable state that induces thrombotic vascular lesions and, in more severe cases, disseminated intravascular coagulation. Increased values of d-dimers are related to the severity of the disease and are associated with worst prognosis. Intensive care studies reported an increased risk of pulmonary embolism and venous thrombosis diseases in COVID-19 compared with the historical control group even in patients who underwent the low-molecular-weight heparin (LWMH) prophylaxis. Patients with COVID-19 who have a stable clinical condition do not require hospitalisation and are treated at home with symptomatic therapy. LWMH is reserved for those with reduced mobility. In this case report, we describe a COVID-19 patient with pulmonary artery thrombosis treated at home

    El sistema logístico y el proceso de almacenamiento en la empresa Sodimac Chiclayo 2021

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    El propósito consistió determinar la relación que existe entre el sistema logístico y el proceso de almacenamiento en la empresa Sodimac Chiclayo 2021, mediante el empleo de una estructura metodológica cuantitativa, de nivel correlacional– descriptivo y de diseño transversal–no experimental; asimismo, se aplicó a la encuesta como técnica mediante el instrumento del cuestionario, ello a una muestra de 36 colaboradores pertenecientes a las áreas de recepción, despacho, reposición, compras e inventario de la empresa Sodimac Chiclayo. En hallazgos principales se evidenciaron que a partir de los resultados descriptivos el nivel de la variable sistema logístico fue alto de acuerdo a la opinión del 61.1%; de igual manera la variable proceso de almacenamiento fue un nivel alto, de acuerdo a la opinión del 69.4%; en cuanto al análisis inferenciales, estos demostraron que hubo una relación significativa y positiva acerca del sistema logístico y proceso de almacenamiento, al encontrarse una significancia inferior al .05, y un coeficiente de correlación del .718. En conclusión, hubo una relación significativa y positiva, entre el sistema logístico y el proceso de almacenamiento en la empresa Sodimac Chiclayo 2021.TesisGestión empresarial y emprendimient

    The in vitro effect of different PRP concentrations on osteoblasts and fibroblasts

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    Objectives:The aim of this study was to assess the biological rationale for the use of platelet-rich plasma (PRP) by evaluating the effect of different concentrations of PRP on osteoblasts (OB) and fibroblasts (FB) function in vitro. Materials and methods:PRP was obtained from volunteer donors using standard protocols. Primary human cultures of oral FBs and OBs were exposed to both activated and non-activated plasma as well as various concentrations of PRP (2.5 x, 3.5 x and max (4.2-5.5 x)). Cell proliferation was evaluated after 24 and 72 h using an MTT proliferation assay. Production of osteocalcin (OCN), osteoprotegerin (OPG) and transforming growth factor beta 1 (TGF-beta 1) was evaluated in OB after 24 and 72 h. Statistical analysis was performed using one-way ANOVA. Results:PRP-stimulated cell proliferation in both OBs and FBs. The effect of different PRP concentrations on cell proliferation was most notable at 72 h. The maximum effect was achieved with a concentration of 2.5 x, with higher concentrations resulting in a reduction of cell proliferation. Upregulation of OCN levels and downregulation of OPG levels were noted with increasing PRP concentrations at both 24 and 72 h. TGF-beta 1 levels were stimulated by increasing concentrations of PRP, with the increased levels being maintained at 72 h. Conclusions:PRP preparations exert a dose-specific effect on oral FBs and OBs. Optimal results were observed at a platelet concentration of 2.5 x, which was approximately half of the maximal concentrate that could be obtained. Increased concentrations resulted in a reduction in proliferation and a suboptimal effect on OB function. Hence, different PRP concentrations may have an impact on the results that can be obtained in vivo

    Enhancing Embedding Representations of Biomedical Data using Logic Knowledge

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    Knowledge Graph Embeddings (KGE) have become a quite popular class of models specifically devised to deal with ontologies and graph structure data, as they can implicitly encode statistical dependencies between entities and relations in a latent space. KGE techniques are particularly effective for the biomedical domain, where it is quite common to deal with large knowledge graphs underlying complex interactions between biological and chemical objects. Recently in the literature, the PharmKG dataset has been proposed as one of the most challenging knowledge graph biomedical benchmark, with hundreds of thousands of relational facts between genes, diseases and chemicals. Despite KGEs can scale to very large relational domains, they generally fail at representing more complex relational dependencies between facts, like logic rules, which may be fundamental in complex experimental settings. In this paper, we exploit logic rules to enhance the embedding representations of KGEs on the PharmKG dataset. To this end, we adopt Relational Reasoning Network (R2N), a recently proposed neural-symbolic approach showing promising results on knowledge graph completion tasks. An R2N uses the available logic rules to build a neural architecture that reasons over KGE latent representations. In the experiments, we show that our approach is able to significantly improve the current state-of-the-art on the PharmKG dataset. Finally, we provide an ablation study to experimentally compare the effect of alternative sets of rules according to different selection criteria and varying the number of considered rules

    Black hole scaling relations of active and quiescent galaxies: Addressing selection effects and constraining virial factors

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    Local samples of quiescent galaxies with dynamically measured black hole masses (Mbh) may suffer from an angular resolution-related selection effect, which could bias the observed scaling relations between Mbh and host galaxy properties away from the intrinsic relations. In particular, previous work has shown that the observed Mbh-Mstar (stellar mass) relation is more strongly biased than the Mbh-sigma (velocity dispersion) relation. Local samples of active galactic nuclei (AGN) do not suffer from this selection effect, as in these samples Mbh is estimated from megamasers and/or reverberation mapping-based techniques. With the exception of megamasers, Mbh-estimates in these AGN samples are proportional to a virial coefficient fvir. Direct modelling of the broad line region suggests that fvir~3.5. However, this results in a Mbh-Mstar relation for AGN which lies below and is steeper than the one observed for quiescent black hole samples. A similar though milder trend is seen for the Mbh-sigma relation. Matching the high-mass end of the Mbh-Mstar and Mbh-sigma relations observed in quiescent samples requires fvir~15 and fvir~7, respectively. On the other hand, fvir~3.5 yields Mbh-sigma and Mbh-Mstar relations for AGN which are remarkably consistent with the expected `intrinsic' correlations for quiescent samples (i.e., once account has been made of the angular resolution-related selection effect), providing additional evidence that the sample of local quiescent black holes is biased. We also show that, as is the case for quiescent black holes, the Mbh-Mstar scaling relation of AGN is driven by velocity dispersion, thus providing additional key constraints to black hole-galaxy co-evolution models.Comment: 15 pages, 5 Figures. MNRAS, accepte

    An Environmentally Friendly Practice Used in Olive Cultivation Capable of Increasing Commercial Interest in Waste Products from Oil Processing

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    In the Rural Development Plan (2014–2020), the European Commission encouraged the conversion and supported the maintenance of organic farming. Organic olive oil (bioEVOO) production involves the use of environmentally sustainable fertilizers and the recycling of olive pomace (Pom) and olive vegetation waters (VW) to reduce the environmental impact of these wastes. An ecofriendly way to recycle olive wastes is to reuse them to extract bioactive compounds. In this study, the total phenolic compounds content, their profile and dosage, the antioxidant action in oil, pomace, and vegetation water was evaluated when the Trichoderma harzianum M10 was used as a biostimulant in agriculture. Two spectrophotometric tests (2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2′‐azinobis (3‐ethylbenzothiazoline‐6‐sulfonic) acid (ABTS)) evaluated the antioxidant potential of samples, a spectrophotometric method estimated total phenolic content, and an Ultra‐High‐Performance Liquid Chromatography (UHPLC)–Orbitrap method evaluated the phenolics profile. Our results showed that the biostimulation improved the antioxidant potential and the total concentration of phenolics in the bioEVOO and bio‐pomace (bioPom) samples and mainly enhanced, among all classes of phenolic compounds, the production of the flavonoids and the secoiridoids. Moreover, they demonstrated the Trichoderma action in the mevalonate pathway to produce phenols for the first time. The decisive action of the Thricoderma on the production of phenolic compounds increases the economic value of the waste materials as a source of bioactive compounds useful for the pharmaceutical, cosmetic, and food industries

    The HIV-1 Nef Protein Interferes with Phosphatidylinositol 3-Kinase Activation 1

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    nef is a human immunodeficiency virus (HIV) gene encoding a 27-kDa myristoylated protein with structural features of a signal transducing molecule, but whose functions are largely unknown. We studied the interactions of Nef with the signal transduction pathways triggered by the platelet-derived growth factor (PDGF) receptor. The association of phosphatidylinositol (PI) 3-kinase with the activated receptor was severely impaired by nef expression. Conversely, PDGF-induced receptor tyrosine phosphorylation, binding to phospholipase C-gamma and to Ras-GAP were not modified. Microtubule-associated protein kinase activation and intracellular calcium influx in response to PDGF were either unaffected or only slightly enhanced. Nef significantly reduced the proliferative response to the growth factor, while the chemotactic response was unchanged. These data show that Nef affects selectively the PI 3-kinase signaling pathway and suggest that this interference results in some of the HIV adverse effects on host cell functions

    Aesthetic- And patient- related outcomes following root coverage procedures: A systematic review and network meta- analysis

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    BackgroundAim of this systematic review (SR) of randomized controlled trials (RCTs) was to evaluate effect of different flap designs and graft materials for root coverage, in terms of aesthetics, patient satisfaction and self- reported morbidity (post- operative pain/discomfort).Material and MethodsA comprehensive literature search was performed. A mixed- modelling approach to network meta- analysis was utilized to formulate direct and indirect comparisons among treatments for Root Coverage Esthetic Score (RES), with its individual components, and for subjective patient- reported satisfaction and post- operative pain/discomfort (visual analogue scale (VAS) of 100).ResultsTwenty- six RCTs with a total of 867 treated patients (1708 recessions) were included. Coronally Advanced Flap (CAF) + Connective Tissue Graft (CTG) (0.74 (95% CI [0.24, 1.26], p = .005)), Tunnel (TUN) + CTG (0.84 (95% CI [0.15, 1.53]), p = .01) and CAF + Graft substitutes (GS) (0.55 (95% CI [0.006, 1.094], p = .04)) were significantly associated with higher RES than CAF. No significant difference between CAF + CTG and TUN + CTG was detected (0.09 (95% CI [- 0.54, 0.72], p = .77)). Addition of CTG resulted in less natural tissue texture (- 0.21 (95% CI [- 0.34, - 0.08]), p = .003) and gingival colour (- 0.06 (95% CI [- 0.12, - 0.03], p = .03)) than CAF. CTG techniques were associated with increased morbidity.ConclusionsConnective tissue graft procedures showed highest overall aesthetic performance for root coverage, although graft integration might impair soft tissue colour and appearance. Additionally, CTG- based techniques were also correlated with a greater patient satisfaction and morbidity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163404/2/jcpe13346.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163404/1/jcpe13346_am.pd

    Customized biofilm device for antibiofilm and antibacterial screening of newly developed nanostructured silver and zinc coatings

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    Background Bacterial colonisation on implantable device surfaces is estimated to cause more than half of healthcare-associated infections. The application of inorganic coatings onto implantable devices limits/prevents microbial contaminations. However, reliable and high-throughput deposition technologies and experimental trials of metal coatings for biomedical applications are missing. Here, we propose the combination of the Ionized Jet Deposition (IJD) technology for metal-coating application, with the Calgary Biofilm Device (CBD) for high-throughput antibacterial and antibiofilm screening, to develop and screen novel metal-based coatings. Results The films are composed of nanosized spherical aggregates of metallic silver or zinc oxide with a homogeneous and highly rough surface topography. The antibacterial and antibiofilm activity of the coatings is related with the Gram staining, being Ag and Zn coatings more effective against gram-negative and gram-positive bacteria, respectively. The antibacterial/antibiofilm effect is proportional to the amount of metal deposited that influences the amount of metal ions released. The roughness also impacts the activity, mostly for Zn coatings. Antibiofilm properties are stronger on biofilms developing on the coating than on biofilms formed on uncoated substrates. This suggests a higher antibiofilm effect arising from the direct contact bacteria-coating than that associated with the metal ions release. Proof-of-concept of application to titanium alloys, representative of orthopaedic prostheses, confirmed the antibiofilm results, validating the approach. In addition, MTT tests show that the coatings are non-cytotoxic and ICP demonstrates that they have suitable release duration (> 7 days), suggesting the applicability of these new generation metal-based coatings for the functionalization of biomedical devices.Conclusions The combination of the Calgary Biofilm Device with the Ionized Jet Deposition technology proved to be an innovative and powerful tool that allows to monitor both the metal ions release and the surface topography of the films, which makes it suitable for the study of the antibacterial and antibiofilm activity of nanostructured materials. The results obtained with the CBD were validated with coatings on titanium alloys and extended by also considering the anti-adhesion properties and biocompatibility. In view of upcoming application in orthopaedics, these evaluations would be useful for the development of materials with pleiotropic antimicrobial mechanisms
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