586 research outputs found

    Seismic retrofit of an existing reinforced concrete building with buckling-restrained braces

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    Background: The seismic retrofitting of frame structures using hysteretic dampers is a very effective strategy to mitigate earthquake-induced risks. However, its application in current practice is rather limited since simple and efficient design methods are still lacking, and the more accurate time-history analysis is time-consuming and computationally demanding. Aims: This paper develops and applies a seismic retrofit design method to a complex real case study: An eight-story reinforced concrete residential building equipped with buckling-restrained braces. Methods: The design method permits the peak seismic response to be predicted, as well as the dampers to be added in the structure to obtain a uniform distribution of the ductility demand. For that purpose, a pushover analysis with the first mode load pattern is carried out. The corresponding story pushover curves are first idealized using a degrading trilinear model and then used to define the SDOF (Single Degree-of-Freedom) system equivalent to the RC frame. The SDOF system, equivalent to the damped braces, is designed to meet performance criteria based on a target drift angle. An optimal damper distribution rule is used to distribute the damped braces along the elevation to maximize the use of all dampers and obtain a uniform distribution of the ductility demand. Results: The effectiveness of the seismic retrofit is finally demonstrated by non-linear time-history analysis using a set of earthquake ground motions with various hazard levels. Conclusion: The results proved the design procedure is feasible and effective since it achieves the performance objectives of damage control in structural members and uniform ductility demand in dampers

    The ethics of people analytics: risks, opportunities and recommendations

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    Purpose: This research analyzed the existing academic and grey literature concerning the technologies and practices of people analytics (PA), to understand how ethical considerations are being discussed by researchers, industry experts and practitioners, and to identify gaps, priorities and recommendations for ethical practice. Design/methodology/approach: An iterative “scoping review” method was used to capture and synthesize relevant academic and grey literature. This is suited to emerging areas of innovation where formal research lags behind evidence from professional or technical sources. Findings: Although the grey literature contains a growing stream of publications aimed at helping PA practitioners to “be ethical,” overall, research on ethical issues in PA is still at an early stage. Optimistic and technocentric perspectives dominate the PA discourse, although key themes seen in the wider literature on digital/data ethics are also evident. Risks and recommendations for PA projects concerned transparency and diverse stakeholder inclusion, respecting privacy rights, fair and proportionate use of data, fostering a systemic culture of ethical practice, delivering benefits for employees, including ethical outcomes in business models, ensuring legal compliance and using ethical charters. Research limitations/implications: This research adds to current debates over the future of work and employment in a digitized, algorithm-driven society. Practical implications: The research provides an accessible summary of the risks, opportunities, trade-offs and regulatory issues for PA, as well as a framework for integrating ethical strategies and practices. Originality/value: By using a scoping methodology to surface and analyze diverse literatures, this study fills a gap in existing knowledge on ethical aspects of PA. The findings can inform future academic research, organizations using or considering PA products, professional associations developing relevant guidelines and policymakers adapting regulations. It is also timely, given the increase in digital monitoring of employees working from home during the Covid-19 pandemic

    The IkB kinase inhibitor nuclear factor-kB essential modulator–binding domain peptide for inhibition of balloon injury-induced neointimal formation

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    Objective—The activation of nuclear factor-kB (NF-kB) is a crucial step in the arterial wall’s response to injury. The identification and characterization of the NF-kB essential modulator– binding domain (NBD) peptide, which can block the activation of the IkB kinase complex, have provided an opportunity to selectively abrogate the inflammation-induced activation of NF-kB. The aim of the present study was to evaluate the effect of the NBD peptide on neointimal formation.<br></br> Methods and Results—In the rat carotid artery balloon angioplasty model, local treatment with the NBD peptide (300 microg/site) significantly reduced the number of proliferating cells at day 7 (by 40%; P<0.01) and reduced injury-induced neointimal formation (by 50%; P<0.001) at day 14. These effects were associated with a significant reduction of NF-kB activation and monocyte chemotactic protein-1 expression in the carotid arteries of rats treated with the peptide. In addition, the NBD peptide (0.01 to 1 micromol/L) reduced rat smooth muscle cell proliferation, migration, and invasion in vitro. Similar results were observed in apolipoprotein E-/-, mice in which the NBD peptide (150 microg/site) reduced wire-induced neointimal formation at day 28 (by 47%; P<0.01).<br></br> Conclusion—The NBD peptide reduces neointimal formation and smooth muscle cell proliferation/migration, both effects associated with the inhibition of NF-kB activation

    MicroRNA deregulation in thyroid cancer

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    In cancer microRNAs are often dysregulated with their expression patterns being correlated with clinically relevant tumor characteristics. Recently, microRNAs were shown to be directly involved in cancer initiation and progression. Despite the large amount of data showing strong correlations between cancer phenotype and microRNAs aberrant expression, very little is known about the molecular mechanisms inducing such deregulation. Thyroid carcinomas comprise a heterogeneous group of neoplasms with distinctive clinical and pathological characteristics. Activating mutations in Ras genes are frequently found in poorly differentiated and in anaplastic thyroid carcinomas. We have recently shown that oncogenic activation of Ras is able to change the expression of several microRNAs in thyroid epithelial cells. One of the top aberrantly expressed ones is miR-21, a microRNA prevoiusly reported overexpressed in a wide variety of cancers and causally linked to cellular proliferation, survival and migration. By using an inducible Ras oncogene we demonstrated that constitutively active Ras induce overexpression of miR-21 at very early times after its activation, and that such overexpression is maintained at later times as well as in chronically Ras-transformed cells. Analysis of a panel of thyroid tumors with different hystotypes revealed that miR-21 is overexpressed mainly in anaplastic carcinomas, thus correlating with the most aggressive phenotype. Interestingly, this induction seems to be cell-type specific, since the inducible Ras oncogene is unable to increase miR-21 levels in cultured fibroblasts. Moreover, our data show that at least two different Ras downstream pathways are necessary to induce miR-21 expression. We then asked if the ability of Ras in inducing miR-21 overexpression is verified in vivo. To answer this question we analyzed the expression of this microRNA in a mouse model of Ras-induced lung tumorigenesis, showing that Ras constitutive activation is able to increase miR-21 levels in normal lung and that the Ras-initiated lung cancer progression is accompained by a further increase in miR-21 expression. Taken together, our data strongly suggest that the oncogenic activation of Ras could be responsible for the increased expression of miR-21 frequently observed in human cancers

    Thermal Conductivity Enhancement of Al2O3 Nanofluid in Ethylene Glycol and Water Mixture

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    AbstractThe ability of nanofluids that exhibits enhanced thermal performance is acknowledged by researchers through studies since decades ago. However, the observation of thermal properties for nanofluids in water and ethylene glycol based is not fully explored yet. Hence, this paper presents the thermal conductivity of water and ethylene glycol (EG) based Al2O3 nanofluid. The 13 nm sized Al2O3 nanoparticles were dispersed into three different volume ratio of water: EG such as 40:60, 50:50 and 60:40 using a two-step method. The measurement of thermal conductivity was performed using KD2 Pro Thermal Properties Analyzer at working temperatures of 30 to 70 ĚŠC for volume concentration of 0.5 to 2.0%. The results indicate that the thermal conductivity increases with the increase of nanofluid concentration and temperature. While the percentage of ethylene glycol increase, the range of thermal conductivity decreases due to ethylene glycol properties. The measurement data of the nanofluids give maximum enhancement of thermal conductivity at condition 2.0% volume concentration, temperature of 70 ĚŠC and for all base fluid

    Acne radar: A new intuitive graphic visualization of quality of life in acne patients

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    Background: There are many instruments available in literature to evaluate the influence of acne on Qualify of Life (QoL), but many of these questionnaires rarely are performed in daily clinical practice. Many of these instruments require a long time for the compilation, and often they are not self completed. There are no simple and intuitive instrument that can be completed by patients alone, with a graphical representation of the results. Objective: To develop a new, rapid and intuitive graphic instrument to a questionnaire allowing both a quick assessment of the impact of acne on patients and, at the same time, increase patient's compliance and self-esteem. Methods: In our study 50 patients were recruited and questionnaire was administered following the main items evaluated in the validated index of QoL from previous studies for acne patients. We have applied an intuitive graph representation, the "Radar Graph", and other statistical methods like the Decisional Map and the Principal Component Analysis, to this questionnaire allowing a quick assessment of the impact of acne on patients. Results: The questionnaire evaluated have 10 items regarding 3 different area: the objective symptoms such as negative perception of their image (imperfection), sting and insomnia; the subjective symptoms such as depression, perception of illness, lack of serenity and shame; and the relational difficulties such as social relationships, working relationships, and intimate relations. The answers are given on a 10-point visual analogue scale. Conclusion: Our survey can be a new, rapid and intuitive graphic instrument to use in clinical practice

    Advanced platelet-rich fibrin as a therapeutic option in the treatment of dry socket: Literature review and case series

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    Alveolar osteitis (AO) is one of the complications that occur after tooth extraction. The aim of this study has been to evaluate the efficacy of Advanced Platelet-rich Fibrin (A-PRF) in the management of pain and the acceleration of wound healing in the treatment of AO. Consecutive patients who were diagnosed with AO, recruited from patients referred to the Oral Surgery Department of the University of Naples Federico II, were enrolled. After local anesthesia, the dry socket was curetted and irrigated with saline. The Platelet-rich Fibrin (PRF) clot was placed in the socket and then covered with an A-PRF membrane. Clinical parameters, such as the degree of pain and rate of granulation tissue (GT) formation, were measured before treatment and after 1, 3, 7, 14, and 21 days. The Friedman test for dependent samples was used to detect the treatment and time effect. Four patients with established AO were included. On all the examination days, the post-operative recovery was uneventful. The pain scores progressively reduced, from an average of 8.5 before treatment to 0.25 on the third day, and the GT formation improved over time. The use of A-PRF in the treatment of AO significantly reduced the pain level and enhanced the wound-healing process
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