87,072 research outputs found
Edifici in acciaio: materiale, calcolo e progetto secondo l'Eurocodice EN-1993-1-1
No full textIl volume costituisce un concreto supporto alla progettazione delle costruzioni in acciaio in accordo all'Eurocodice 3, parte 1.1 - Progettazione delle strutture in acciaio - Regole generali e regole per gli edifici.
Gli argomenti sono trattati proponendo dapprima un inquadramento teorico di carattere generale, mirato a presentare in modo sintetico, ma completo, le principali problematiche e successivamente richiamando le regole e i criteri di verifica dell'Eurocodice. Nel testo sono presenti numerose applicazioni pratiche, sviluppate sulla base dei contenuti riportati: queste applicazioni costituiscono esempi di base utili per per familiarizzare con la normativa di riferimento, oltre che esempi guida su alcuni ricorrenti problemi professionali
A precious metal: iron, an essential nutrient for all cells
No full textIron is an important cofactor required for a no. of essential cell junctions and hence is a vital nutrient. However, iron can also be dangerous as a catalyst of free radical reactions. Accordingly, intracellular iron homeostasis and body iron balance are tightly regulated. In this review, we presented an overview of the remarkable new insights that over the last years have been gained into the multifaceted and sophisticated mol. mechanisms controlling iron acquisition, storage and release. We also reviewed the data about nutrition-related abnormalities of iron metab., such as iron overload and deficiency. Finally, we discussed how pathogenic microorganisms and host cells compete for iron, a battle whose outcome has a relevant role in infection disease
Evaluation of the influence of open and closed-ampoule technologies on particulate matter in small-volume parenterals
No full textSVP in glass ampoules are manufactured using two main different technological production processes: the open-ampoule process (O) and the closed-ampoule process (C). In principle, the open-ampoule production technology should lead to better controlled production process. To test this hypothesis and quantify the possible qualitative differences in the manufactured ampoules, a suitable experimental design was set up. The two ampoule production processes have been compared on the basis of the visible particulate burden. Two batches of ampoules filled with water for injections were produced for each type of process, following conventional industrial procedures. Two samples of 20,000 units were taken from each batch and inspected with different automatic inspection systems: two Brevetti CEA machines (S1, S2-light scattering) and two EISAI machines (S3, S4-light absorbtion). The comparison between the processes was based on the rejection percentage. On both inspection machines the open-ampoule production samples present rejection percentages (ranging from 0.154% to 1.248% rejection percentages) which, on average, are lower than those detected in closed- ampoule production (ranging from 1.434% to 3.86% rejection percentages). The difference between the two processes is even more marked if we also consider the data obtained using inspection machines S3 and S4. The substantial differences in performance of the four inspection machines stress the need to provide for adequate validation procedures
Resilienza, moral distress e benessere psicofisico: uno studio pilota su lavoratori del settore pubblico e privato.
No full textIntroduzione: I cambiamenti che caratterizzano il mondo del lavoro hanno comportato nuovi potenziali fattori di stress per il benessere psico-fisico del lavoratore di oggi e, ancor di più, del futuro.
Obiettivi: Rilevare indici di resilienza e benessere/malessere in varie tipologie di lavoratori, ponendo attenzione al settore e alla posizione ricoperti.
Metodo: É stato somministrato online un questionario anonimo costituito da una parte di dati socio-anagrafici e lavorativi, oltreché da alcune scale per misurare: resilienza (CD-RISC-10), moral distress (questionario ad-hoc), burnout (MBI-GS) e malessere psico-somatico (GHQ-12).
Risultati: 1569 (F= 57.6%, M= 42.4%) lavoratori hanno partecipato allo studio. Di questi, il 72.5% lavora nel privato, mentre l’81.6% riveste una posizione non-dirigenziale. L’1.2% lavora nel settore primario, il 20.5% nel secondario, il 64.9% nel terziario e 13.3% nel quaternario. Per ciò che concerne la posizione ricoperta, i dirigenti si percepiscono maggiormente resilienti rispetto ai non-dirigenti (t(1569)=7.6, p=.000), così come più efficaci professionalmente (t(1569)= 5.78, p=.000). I non-dirigenti riportano punteggi più elevati di cinismo (t(1569)= -4.05, p=.000), disfunzione sociale (t(1569)= -2.01, p=.04) e perdita di fiducia (t(1569)=-3.25, p=.001). Inoltre, i lavoratori del settore secondario riportano maggior moral distress rispetto a chi è impiegato nel settore primario (F(3,1565)=4.5, p=.03). Nel settore pubblico, invece, è riportata maggior perdita di fiducia (t(1569)= 2.02, p=.04). Oltre a ciò, a differenza delle donne, per gli uomini lavorare nel settore pubblico porta a maggior perdita di fiducia rispetto al privato (F(1,1565)=7.33, p=.007). Infine, nel settore privato, la posizione lavorativa non-dirigenziale porta a maggior cinismo rispetto a chi ricopre una posizione dirigenziale (F(1,1565)=23.04, p=.000). Limiti: Modalità di reclutamento (snowball sampling) e utilizzo di misure self-report.
Aspetti innovativi: I risultati pongono l’attenzione sia su nuove possibili forme di stress (es. moral distress) trasversali alle diverse tipologie di lavoratori sia sull’influenza che il settore e la posizione lavorativa possono avere sulla persona
DERRICK CRANE ROBUSTNESS SCENARIOS
No full textThe paper deals with derrick cranes (derricks) that are equipment typically used in the mining industry and focuses on the analysis of few robustness scenarios. Derricks are composed of built-up steel members which are widely and efficiently used in hoisting applications due to their high payloads at relevant outreaches. During the in-service use, local damages might occur and as such, the aim of the paper is to study how such damages influence the overall structural performance. In particular, reference was made to a derrick for which six geometrical configurations and five different damage scenarios have been analysed. Owing it to the extensive use of angles in the built-up compo-nent of each derrick, structural analyses have been carried out by using a commercial refined finite element analysis package (FEAP) offering the warping torsion as an additional degree of freedom for each beam node. Research out-comes allow for a clear identification of the parts of a derrick that should be protected and well-designed to guarantee a robust structure for its entire in-service lif
Cytokines in autoimmune liver diseases
No full textConstitutive production of cytokines is absent or minimal in the normal liver but, in response to various types of injury, hepatocyte and cholangiocyte damage causes the local recruitment of neutrophils and macrophages that produce cytokines and chemokines and the former mediate the inflammatory response that leads to the regeneration of the liver tissue and ultimately, to the deposition of extracellular matrix by activated stellate cells. Cytokine production can have both beneficial and harmful effects, depending on the amount and duration of cytokine release. Within the spectrum of chronic liver diseases, cytokines play a pivotal role in the loss of immune tolerance charachterizing chronic autoimmune hepatitis and primary biliary cirrhosis. This study will provide a general overview on cytokines and focus on their role in initiating and driving the inflammatory infiltrate in autoimmune liver diseases. A better understanding of this process might allow therapeutic interventions to switch off the peculiar inflammatory response wich occurs in these conditions before irreversible damage occurs
I giunti semi-rigidi nelle strutture in profilati a freddo da coils e nelle strutture composte acciaio-calcestruzzo
No full textReactive oxygen species-independent apoptosis in doxorubicin-treated H9c2 cardiomyocytes : role for heme oxygenase-1 down-modulation
No full textIncreased oxidative stress and apoptosis have been implicated in the cardiotoxicity that limits the clinical use of doxorubicin (DOX) as an anti-tumoral drug, but the mechanism of DOX-mediated apoptosis remains unclear. We examined the interplay between oxidative stress and cell death in cardiac-derived H9c2 myocytes exposed to DOX doses in the range of the plasma levels found in patients undergoing chemotherapy. A low DOX concentration (0.25muM) induced apoptosis, whereas the cells treated with the high dose of 2muM also showed necrosis. The production of reactive oxygen species (ROS) and induction of oxidative stress markers was increased in the cells treated with 2muM DOX but not in those treated with the low dose. Surprisingly, heme oxygenase (HO-1) expression was down-modulated in the cells exposed to 0.25muM DOX, and its Bach 1 transcriptional repressor was induced. In line with the role of HO-1 as an anti-apoptotic protein, inhibiting HO-1 activity with SnPPIX was sufficient to induce apoptosis and increased DOX-mediated apoptosis, whereas hemin-induced HO-1 activation prevented DOX-mediated apoptotic cell death. In brief, our findings do not support the hypothesis that oxidative stress plays a role in the apoptotic cell death occurring in cardiomyocytes exposed to low concentrations of DOX, but suggest that DOX may facilitate the apoptosis of cardiomyocytes by inhibiting the anti-apoptotic HO-1
MicroRNAs in autoimmunity and inflammatory bowel disease: Crucial regulators in immune response
No full textMicroRNAs (miRNAs) have recently emerged as a new class of modulators of gene expression at the posttranscriptional level. The function of miRNA is the control of protein production by targeting mRNAs for translational repression or degradation. MiRNAs play a critical role in many biological processes such as cellular proliferation and maturation, apoptosis, regulation of chronic inflammation and development of cancer. It has recently been discovered that miRNAs are differentially expressed in autoimmune diseases (AID) and miRNA regulation may impact in the development or prevention of AID. In this paper we review the importance of miRNAs in AID in particular in inflammatory bowel disease (IBD). IBD is an AID whose pathophysiology remains uncertain. It is generally hypothesized that IBD is caused by the enteric microflora in genetically predisposed patients with an immune dysregulation in the gastrointestinal tract. Knowing the typical miRNA pattern of IBD will improve our knowledge of the pathogenesis of this disease and will lead to future well-focused projects to study the regulatory function of such miRNAs. Furthermore, it is possible that some miRNAs are specific to IBD and could serve as biomarkers with clinical applications for the diagnosis or assessment of disease activity. (C) 2010 Elsevier B.V. All rights reserved
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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