Wood pre-treatments a short review

Pre-treatments to improve wood durability, as well as their impact on Life Cycle Assessment (LCA) are important aspects to take into account in the first phase of a project. The objective of this paper is to study the effects pre-treatments have on durability of wood when compared with the possibility of reusing wood components over their entire life cycle. Studies on how artificial/natural processes change the mechanical, physical and chemical properties of wood are undertaken in different scientific fields. The biology of wood studies the chemical and natural processes that affect it. The study is often focussed on the biochemistry and molecular composition of wood, and analyses how the various chemical processes (both natural and otherwise) affect the characteristics of the material, determining the decay of performance and the deterioration of the components. Material engineering studies the mechanical modifications of parameters (e.g. modulus of elasticity, modulus of rupture) without considering the implication that pre-treatment choices have in the building process. In this article we provide a review of the most important pre-treatments for improving wood properties (e.g. strength, water absorption, etc.) compared with processing times and LCA parameters. In particular, we started with a literature review to gather an overall understanding about the different processes that can be applied to improve material durability, and propose a preliminary pre-treatment classification. Durability can be defined as the material’s capability to ensure adequate values of performance and functional levels over its entire lifetime. As known, wood has undesirable reactions to atmospheric agents if it’s not sufficiently protected. There are different pre-treatments that can change its physical, chemical, or mechanical properties. These processes can be applied alone or in combination [1] and are subdivided into: Thermal pre-treatments Chemical pre-treatments Mechanical pre-treatments Thermal pre-treatments use high temperature steam (up to 230 °C) or hot water (up to 180 °C) [5]. Laboratory tests show that these processes increase the dimensional stability of wood and resistance to moisture variations. In particular, these results were widely observed in wood panels (OSB, MDF, WPC). It is also observed that these wood preservation techniques prevent or at least reduce the possibility of attacks by biological agents such as insects and fungi [3]. A drawback of this process is a decrease in the mechanical properties of wood. Different laboratory tests have shown how both the modulus of elasticity (MOE) and modulus of rupture (MOR) steadily decrease after the thermal pre-treatment. Chemical pre-treatments can be applied on the external layer of the material, or by means of long lasting impregnation of the components. Chemical treatments are usually administered on wood to prevent performance reduction, improve water resistance, reduce the effects of ultraviolet radiation, or decrease flammability [6][7].The property of the material to absorb chemical treatments is related to material’s hydrophilicity. Treated wood must be non-toxic and recyclable at the end of its service-life [3]and this property is not always guaranteed with all chemical treatments. Mechanical pre-treatments are used to reduce the internal moisture. Different tests were performed in China and Japan, to investigate the relation between compression rate and moisture content. There is no clear evidence of how the compression ratio, compression direction, and compression speed affect the decrease of moisture content and mechanical properties. The speed of compression should influence the efficiency of processing, and the final moisture content [8].The tests show that the material undergoes no substantial decrease of both MOE and MOR parameters. In conclusion, besides providing indications about the different pre-treatment methods, this paper will also assess their impact on the environment. In this study we want to propose an innovative approach to understand both the advantages and disadvantages of the described treatment procedures, thus providing a novel contribution in the field of construction and wood design

VALORIZZAZIONE DEI COMPONENTI FENOLICI E POLIFENOLICI NUTRACEUTICI DELL'OLIO D'OLIVA: ESTRAZIONE, PURIFICAZIONE E SVILUPPO DI UN METODO ANALITICO PER L'OLEACEINA

L’importanza dell’olio extravergine di oliva sulla salute e sullo stato di benessere generale è nota fin dai tempi antichi e proprio per questo motivo esso fu tradizionalmente considerato come una sostanza a metà strada tra l’alimento ed il medicinale. Grazie al suo contenuto ricco di acidi grassi monoinsaturi, in particolare di acido oleico, l’olio extravergine di oliva è in grado di proteggere la mucosa gastrica, in quanto diminuisce la secrezione di acido cloridrico , e di inibire la secrezione della bile. Inoltre è stata dimostrata la sua capacità di ridurre l’incidenza di alcune malattie autoimmuni e del tumore al seno e al colon-retto. L’olio extravergine d’oliva, è costituito in minima parte anche da una porzione più polare nella quale si può distinguere la frazione dei composti fenolici e polifenolici che è risultata fondamentale per le proprietà salutistiche dell’olio extravergine di oliva. La frazione dei composti fenolici e polifenolici comprende: alcoli fenolici, come il tirosolo e l’idrossitirosolo, derivati secoiridoidi, lignani e flavonoidi. I derivati secoiridoidi a loro volta comprendono l’oleuropeina aglicone (presente soltanto nelle foglie e nelle olive) e l’oleaceina, quali derivati dell’idrossitirosolo , l’oleocantale e il ligostroside aglicone, quali derivati del tirosolo. Essi riducono lo stress ossidativo e sono noti svolgere un’azione vasoprotettiva, antinfiammatoria, anticoagulante e antitumorale. In particolare studi recenti hanno focalizzato la loro attenzione sugli effetti salutistici dell'oleaceina. Venne identificata per la prima volta nelle foglie dell'olivo nel 1996 da K.Hansen, in seguito ad uno studio sulle proprietà ipotensive delle foglie di olivo (Olea europaea L.), quindi dei principi attivi in esse contenuti. Nello specifico, Hansen e colleghi osservarono che l’oleaceina agiva sul sistema Renina-Angiontensina- Aldosterone e, in particolare, aveva dimostrato attività inibitoria nei confronti dell’enzima ACE. Da questa sua attività ne derivò il suo nome, infatti “Ole-“da “oleo, olio” e “ace-in” da ACE inibitore. Negli ultimi anni sono stati pubblicati diversi lavori di ricerca che si sono concentrati sul ruolo dell'oleaceina come antiossidante e nella prevenzione dei danni cardiovascolari essendo essa un inibitore dell’endopeptidasi neutra (NEP). Il lavoro sperimentale di questa tesi si inserisce in un ampio progetto multidisciplinare che si propone di studiare le proprietà nutraceutiche dell’olio extravergine d’oliva e dei suoi componenti fenolici e polifenolici, in particolare dei composti secoiridoidi, oleocantale e oleaceina. Nel laboratorio di ricerca in cui ho svolto il mio lavoro di tesi, è stato già messo a punto un metodo di estrazione e purificazione dell' oleocantale dall'olio extravergine d'oliva. Lo scopo di questa tesi è stato quello di mettere a punto un metodo di estrazione e purificazione dell’oleaceina dalle foglie di olivo, dalle olive e dall’olio di oliva. Sulla base del metodo utilizzato in precedenza per l'estrazione e purificazione dell'oleocantale e apportando delle modifiche per quanto riguarda la purificazione, è stato possibile mettere a punto un metodo per l'ottenimento di campioni di oleaceina pura. Tale metodo consta principalmente di una fase di estrazione e di una fase di purificazione. Nella fase di estrazione i solventi utilizzati sono diversi a seconda che si tratti di foglie/olive oppure olio di oliva. La fase di purificazione avviene per Flash cromatografia seguita da una lastra preparativa. Con l’obiettivo di sviluppare metodiche analitiche per determinare il contenuto di polifenoli in un campione di olio extravergine d'oliva, la seconda parte di questa tesi è stata dedicata alla messa a punto di una metodica analitica mediante HPLC che ha permesso di evidenziare la presenza di tirosolo e idrossitirosolo, oleocantale e oleaceina nell'olio extravergine di oliva. La possibilità di avere a disposizione gli standard di riferimento di idrossitirosolo e tirosolo (in commercio) e oleocantale e oleaceina da noi purificati, ha permesso di ottenere le rette di taratura dei singoli composti che sono state utilizzate per la loro determinazione quantitativa in campioni di olio extravergine di oliva

Les émotions au travail (scientifique): enjeux éthiques et stratégies méthodologiques d'une enquête en terrain intime

Based on a qualitative approach, the article proposes to illustrate the different stages of the elaboration of a methodological package, focusing on emotions that are actively put at work. The investigation was conducted on an intimate field, as it deals with themes such sexuality and HIV. The principal aim of the study is to understand how immigrant women of sub-Saharan origin living in Switzerland manage the secret of their HIV / AIDS positive status. Facing multiple vulnerabilities, the studied population is particularly precarious. This raises several ethical questions that are explored in the text. In particular, the emotional implications for the investigators and the impact of the research on the interviewee’s life are questioned. Reflecting on the mobilization of emotions in the process of research, one epistemological question emerges: could knowing subjects be emotional subjects and vice versa? Finally, the emotions mobilized both by the investigators and the interviewees constitute the raw material on which a situated, felt and committed methodology take place

Artificial intelligence in clinical endoscopy: Insights in the field of videomics

Artificial intelligence is being increasingly seen as a useful tool in medicine. Specifically, these technologies have the objective to extract insights from complex datasets that cannot easily be analyzed by conventional statistical methods. While promising results have been obtained for various -omics datasets, radiological images, and histopathologic slides, analysis of videoendoscopic frames still represents a major challenge. In this context, videomics represents a burgeoning field wherein several methods of computer vision are systematically used to organize unstructured data from frames obtained during diagnostic videoendoscopy. Recent studies have focused on five broad tasks with increasing complexity: quality assessment of endoscopic images, classification of pathologic and nonpathologic frames, detection of lesions inside frames, segmentation of pathologic lesions, and in-depth characterization of neoplastic lesions. Herein, we present a broad overview of the field, with a focus on conceptual key points and future perspectives

Evapotranspiration simulated by CRITERIA and AquaCrop models in stony soils

The performance of a water balance model is also based on the ability to correctly perform simulations in heterogeneous soils. The objective of this paper is to test CRITERIA and AquaCrop models in order to evaluate their suitability in estimating evapotranspiration at the field scale in two types of soil in the Mediterranean region: non-stony and stony soil. The first step of the work was to calibrate both models under the non-stony conditions. The models were calibrated by using observations on wheat crop (leaf area index or canopy cover, and phenological stages as a function of degree days) and pedo-climatic measurements. The second step consisted in the analysing the impact of the soil type on the models performances by comparing simulated and measured values. The outputs retained in the analysis were soil water content (at the daily scale) and crop evapotranspiration (at two time scales: daily and crop season). The model performances were evaluated through four statistical tests: normalised difference (D%) at the seasonal time scale; and relative root mean square error (RRMSE), efficiency index (EF), coefficient of determination (r2) at the daily scale. At the seasonal scale, values of D% were less than 15% in stony and on-stony soils, indicating a good performance attained by both models. At the daily scale, the RRMSE values (2) indicate the inadequacy of AquaCrop to simulate correctly daily evapotranspiration. The higher performance of CRITERIA model to simulate daily evapotranspiration in stony soils, is due to the soil submodel, which requires the percentage skeleton as an input, while AquaCrop model takes into account the presence of skeleton by reducing the soil volume

A role for the centrosome in regulating the rate of neuronal efferocytosis by microglia in vivo

During brain development, many newborn neurons undergo apoptosis and are engulfed by microglia, the tissue-resident phagocytes of the brain, in a process known as efferocytosis. A hallmark of microglia is their highly branched morphology characterized by the presence of numerous dynamic extensions that these cells use for scanning the brain parenchyma and engulfing unwanted material. The mechanisms driving branch formation and apoptotic cell engulfment in microglia are unclear. By taking a live-imaging approach in zebrafish, we show that while microglia generate multiple microtubule-based branches, they only successfully engulf one apoptotic neuron at a time. Further investigation into the mechanism underlying this sequential engulfment revealed that targeted migration of the centrosome into one branch is predictive of phagosome formation and polarized vesicular trafficking. Moreover, experimentally doubling centrosomal numbers in microglia increases the rate of engulfment and even allows microglia to remove two neurons simultaneously, providing direct supporting evidence for a model where centrosomal migration is a rate-limiting step in branch-mediated efferocytosis. Conversely, light-mediated depolymerization of microtubules causes microglia to lose their typical branched morphology and switch to an alternative mode of engulfment, characterized by directed migration towards target neurons, revealing unexpected plasticity in their phagocytic ability. Finally, building on work focusing on the establishment of the immunological synapse, we identified a conserved signalling pathway underlying centrosomal movement in engulfing microglia

Best practices, challenges and innovations in pediatrics in 2019

This paper runs through key progresses in epidemiology, pathomechanisms and therapy of various diseases in children that were issued in the Italian Journal of Pediatrics at the end of last year. Novel research and documents that explore areas such as allergy, critical care, endocrinology, gastroenterology, infectious diseases, neonatology, neurology, nutrition, and respiratory tract illnesses in children have been reported. These observations will help to control childhood illnesses

Design of bioactive biopolymer coating based on Latilactobacillus curvatus 54M16 producer of bacteriocins to preserve the safety of minimally processed fennel

In this study Latilactobacillus curvatus 54M16 (LAB) producing bacteriocins has been incorporated into a sodium caseinate (SC)/guar gum (GG)/beeswax (BW) blend to develop a bioactive film/coating. Moreover, the coating capacity of preserving the safety and quality of minimally processed fennel has been investigated. Results showed significant antimicrobial activity of the bioactive film against L. innocua C6 during 28 days of storage at 4 ◦C, 10 ◦C, 20 ◦C and 30 ◦C. The presence of LAB did not affect the moisture content, thickness, color, and solubility of the SC/GG/BW films, whereas caused a reduction of the film’s stiffness and water vapor permeability. Counts of L. innocua on fennels processed with the active coating showed a significant reduction of about 2 log cycles at the end of storage with respect to the control samples for which L. innocua ranged from 3.42 to 4.13 log CFU/cm2 . Moreover, microbial diversity dramatically decreased in samples coated with antimicrobial film, that were dominated by Lactobacillus sp. In conclusion, the developed bioactive coating can be used as an antimicrobial coating to improve minimally processed fennel safet