947 resultados para New products
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The purine ring system is one of the most widely distributed N-heterocycles in Nature [1] and many structurally modified purine nucleosides and nucleotides have activities ranging from antineoplastic and antiviral to antihypertensive, antiasthmatic, antituberculosis, etc [2]. Among the purine derivatives, we have put our attention on natural N-alkylpurines such as the asmarines or agelasimines, a group of secondary metabolites isolated from marine sponges with very interesting biological properties [3]. They have a diterpenoid moiety attached to the N-7 nitrogen atom of an adenine and are usually isolated in very small quantities, which limited their structure-activity relationship studies. Our research group has been involved for years in the design, synthesis and biological evaluation of cytotoxic compounds related to natural products, including the chemoinduction of bioactivity on inactive terpenoids [4]. These diterpenoid include compounds such as communic or cupressic acids that bear decaline moieties very close to those present in the above-mentioned marine natural products. These facts prompted us to design and prepare new terpenylpurine derivatives starting from natural monoterpenoids and diterpenoids, commercially available or isolated from their natural sources and transformed into appropriate alkylated agents. Thus, we have prepared purines alkylated at N-7 and N-9 positions with isoprenoids, monoterpenoids and diterpenoids, using two different synthetic approaches: from 6-chloropurine or from 4,5-diamine-6-chloropyrimidine. The structure of the synthesized purines are shown in the following figure. The purine analogues synthesized have been evaluated for their cytotoxicity against four tumour human cell lines (breast, non-small lung, cervical and hepatocellular carcinoma) and non-tumour cells (porcine liver primary cells). The most cytotoxic derivatives were those with a diterpenoid rest on the purine. The results obtained allowed to draw conclusions on the structure-activity relationship of the compounds in order to evaluate the influence of the terpenyl size on their cytotoxic properties.
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Is a radical nanotechnology involving the construction of macroscopic products via software-directed manipulation of single molecules possible? Are we only a few decades away from a technological utopia where virtually any product may be constructed via molecular manufacturing? These and other similarly provocative questions formed the backdrop for a well-attended debate on nanotechnology held in the University of Nottingham last year (26 August 2005).
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Directed internship
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Terephthalic acid (PTA) is one of the monomers used for the synthesis of the polyester, polyethylene terephthalate (PET), that is used for the large-scale manufacture of synthetic fibers and plastic bottles. PTA is largely produced from the liquid-phase oxidation of petroleum-derived p-xylene (PX). However, there are now ongoing worldwide efforts exploring alternative routes for producing PTA from renewable, biomass resources.
In this thesis, I present a new route to PTA starting from the biomass-derived platform chemical, 5-hydroxymethylfurfural (HMF). This route utilizes new, selective Diels-Alder-dehydration reactions involving ethylene and is advantageous over the previously proposed Diels-Alder-dehydration route to PTA from HMF via 2,5-dimethylfuran (DMF) since the H2 reduction of HMF to DMF is avoided. Specifically, oxidized derivatives of HMF are reacted as is, or after etherification-esterification with methanol, with ethylene over solid Lewis acid catalysts that do not contain strong Brønsted acids in order to synthesize intermediates of PTA and its equally important diester, dimethyl terephthalate (DMT). The partially oxidized HMF, 5-(hydroxymethyl)furoic acid (HMFA) is reacted with high pressure ethylene over a pure-silica molecular sieve catalyst containing framework tin (Sn-Beta) to produce the Diels-Alder-dehydration product, 4-(hydroxymethyl)benzoic acid (HMBA), with ~30% selectivity at ~20% yield. If HMFA is protected with methanol to form methyl 5-(methoxymethyl)furan-2-carboxylate (MMFC), MMFC can react with ethylene in the presence of a pure-silica molecular sieve containing framework zirconium (Zr-Beta) to produce methyl 4-(methoxymethyl)benzenecarboxylate (MMBC) with >70% selectivity at >20% yield. HMBA and MMBC can then be oxidized to produce PTA and DMT, respectively. When Lewis acid containing mesoporous silica (MCM-41) and amorphous silica, or Brønsted acid containing zeolites (Al-Beta), are used as catalysts, a significant decrease in selectivity/yield of the Diels-Alder-dehydration product is observed.
An investigation to elucidate the reaction network and side products in the conversion of MMFC to MMBC was performed, and the main side products are found to be methyl 4-formylcyclohexa-1,3-diene-1-carboxylate and the ethylene Diels-Alder adduct of this cyclohexadiene. These products presumably form by a different dehydration pathway of the MMFC/ethylene Diels-Alder adduct and should be included when determining the overall selectivity to PTA or DMT since, like MMBC, these compounds are precursors to PTA or DMT.
Fundamental physical and chemical information on the ethylene Diels-Alder-dehydration reactions catalyzed by the Lewis acid-containing molecular sieves was obtained. Madon-Boudart experiments using Zr-Beta as catalyst show that the reaction rates are limited by chemical kinetics only (physical transport limitations are not present), all the Zr4+ centers are incorporated into the framework of the molecular sieve, and the whole molecular sieve crystal is accessible for catalysis. Apparent activation energies using Zr-Beta are low, suggesting that the overall activation energy of the system may be determined by a collection of terms and is not the true activation energy of a single chemical step.
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The Orthodox church(es) share a common commitment to the unity of dogma and spirituality. There is, however, no doctrinal formulation that comes close to a form of political theology at a pan-Orthodox level. This means that the Orthodox churches’ attitude towards the European Union (EU) is driven by their ecclesial diversity and by complex inter-ecclesial relations. More fundamentally they share a fragmented and plural, theological objection to the very ideas of Europe and the West. This has been further complicated by the emergence of a substantial Orthodox diaspora from Eastern Europe, Russia, and the Middle East living across the breadth of the European continent. Consequently the ecclesial identity and self-perception of the autocephalous Orthodox churches is changing. These churches are becoming increasingly transnational and extra-territorial. With this, their perception of Europe and the West, as seen through the eyes of their diaspora communities, is altering from “threat” to “home” (Makrides and Uffelmann, 2003). The growing diaspora will not only impact the Christian demographics of Europe but will also transform the Eastern Churches’ view of Europe and the EU (Leustean, 2009; 2011; 2013; 2014a; 2014b).
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Poster presented at the 7th European Academy of Forensic Science Conference. Prague, 6-11 September 2015
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Freeze drying technology can give good quality attributes of vegetables and fruits in terms of color, nutrition, volume, rehydration kinetics, stability during storage, among others, when compared with solely air dried ones. However, published scientific works showed that treatments applied before and after air dehydration are effective in food attributes, improving its quality. Therefore, the hypothesis of the present thesis was focus in a vast research of scientific work that showed the possibility to apply a pre-treatment and a post-treatment to food products combined with conventional air drying aiming being close, or even better, to the quality that a freeze dried product can give. Such attributes are the enzymatic inactivation, stability during storage, drying and rehydration kinetics, color, nutrition, volume and texture/structure. With regard to pre-treatments, the ones studied along the present work were: water blanching, steam blanching, ultrasound, freezing, high pressure and osmotic dehydration. High electric pulsed field was also studied but the food attributes were not explained on detailed. Basically, water and steam blanching showed to be adequate to inactivate enzymes in order to prevent enzymatic browning and preserve the product quality during long storage periods. With regard to ultrasound pre-treatment the published results pointed that ultrasound is an effective pre-treatment to reduce further drying times, improve rehydration kinetics and color retention. On the other hand, studies showed that ultrasound allow sugars losses and, in some cases, can lead to cell disruption. For freezing pre-treatment an overall conclusion was difficult to draw for some food attributes, since, each fruit or vegetable is unique and freezing comprises a lot of variables. However, for the studied cases, freezing showed to be a pre-treatment able to enhance rehydration kinetics and color attributes. High pressure pre-treatment showed to inactivate enzymes improving storage stability of food and showed to have a positive performance in terms of rehydration. For other attributes, when high pressure technology was applied, the literature showed divergent results according with the crops used. Finally, osmotic dehydration has been widely used in food processing to incorporate a desired salt or sugar present in aqueous solution into the cellular structure of food matrix (improvement of nutrition attribute). Moreover, osmotic dehydration lead to shorter drying times and the impregnation of solutes during osmose allow cellular strengthens of food. In case of post-treatments, puffing and a new technology denominated as instant controlled pressure drop (DIC) were reported in the literature as treatments able to improve diverse Abstract Effect of Pre-treatments and Post-treatments on Drying Products x food attributes. Basically, both technologies are similar where the product is submitted to a high pressure step and the process can make use of different heating mediums such as CO2, steam, air and N2. However, there exist a significant difference related with the final stage of both which can comprise the quality of the final product. On the other hand, puffing and DIC are used to expand cellular tissues improving the volume of food samples, helping in rehydration kinetics as posterior procedure, among others. The effectiveness of such pre and/or post-treatments is dependent on the state of the vegetables and fruits used which are also dependent of its cellular structure, variety, origin, state (fresh, ripe, raw), harvesting conditions, etc. In conclusion, as it was seen in the open literature, the application of pre-treatments and post-treatments coupled with a conventional air dehydration aim to give dehydrated food products with similar quality of freeze dried ones. Along the present Master thesis the experimental data was removed due to confidential reasons of the company Unilever R&D Vlaardingen
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Transboundary animal diseases can have very severe socio-economic impacts when introduced into new regions. The history of disease incursions into the European Union suggests that initial outbreaks were often initiated by illegal importation of meat and derived products. The European Union would benefit from decision-support tools to evaluate the risk of disease introduction caused by illegal imports in order to inform its surveillance strategy. However, due to the difficulty in quantifying illegal movements of animal products, very few studies of this type have been conducted. Using African swine fever as an example, this work presents a novel risk assessment framework for disease introduction into the European Union through illegal importation of meat and products. It uses a semi-quantitative approach based on factors that likely influence the likelihood of release of contaminated smuggled meat and products, and subsequent exposure of the susceptible population. The results suggest that the European Union is at non-negligible risk of African swine fever.
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The cemeterial units, are places of social practices of everyday life and worship and the tomb where nostalgia can be externalized and the memory of the deceased revered. In Western societies we can find a category of artifacts meant to evoke the memory or honor the dead. In this paper we we mention three examples of products that enabled a reflection on the concepts that gave rise to their ways, and that risks to fit them into a new "material culture", in that it may have created a break with the traditional system codes and standards shared by companies, and its manifestations in relation to the physical creation of this category of products. This work offers a reflection on the Design Products.What probably makes it special is the field where it is located: the design of products in one post mortem memory. Usually made of granite rock or marble, have the form of plate or tablet, open book or rolled sheet. On one side have a photograph of the person who intend to honor and inscriptions. The thought of inherent design of this work put on one side the intricate set of emotions that this type of product can generate, and other components more affordable, and concerning the form, function and object interactions with users and with use environments. In the definition of the problem it was regarded as mandatory requirements: differentiation, added value and durability as key objectives.The first two should be manifested in the various components / product attributes. The aesthetic and material/structural durability of product necessarily imply the introduction of qualifying terms and quantitative weights, which positively influence the generation and evaluation of concepts based on the set of 10 principles for the project that originated a matrix as a tool to aid designing products. The concrete definition of a target audience was equally important. At this stage, the collaboration of other experts in the fields of psychology and sociology as disciplines with particular ability to understand individuals and social phenomena respectively was crucial. It was concluded that a product design to honor someone post mortem, should abandon the more traditional habits and customs to focus on identifying new audiences. Although at present it can be considered a niche market, it is believed that in the future may grow as well as their interest in this type of products.
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Biofilms are microbial communities characterized by their adhesion to solid surfaces and the production of a matrix of exopolymeric substances, consisting of polysaccharides, proteins, DNA and lipids, which surround the microorganisms lending structural integrity and a unique biochemical profile to the biofilm. Biofilm formation enhances the ability of the producer/s to persist in a given environment. Pathogenic and spoilage bacterial species capable of forming biofilms are a significant problem for the healthcare and food industries, as their biofilm-forming ability protects them from common cleaning processes and allows them to remain in the environment post-sanitation. In the food industry, persistent bacteria colonize the inside of mixing tanks, vats and tubing, compromising food safety and quality. Strategies to overcome bacterial persistence through inhibition of biofilm formation or removal of mature biofilms are therefore necessary. Current biofilm control strategies employed in the food industry (cleaning and disinfection, material selection and surface preconditioning, plasma treatment, ultrasonication, etc.), although effective to a certain point, fall short of biofilm control. Efforts have been explored, mainly with a view to their application in pharmaceutical and healthcare settings, which focus on targeting molecular determinants regulating biofilm formation. Their application to the food industry would greatly aid efforts to eradicate undesirable bacteria from food processing environments and, ultimately, from food products. These approaches, in contrast to bactericidal approaches, exert less selective pressure which in turn would reduce the likelihood of resistance development. A particularly interesting strategy targets quorum sensing systems, which regulate gene expression in response to fluctuations in cell-population density governing essential cellular processes including biofilm formation. This review article discusses the problems associated with bacterial biofilms in the food industry and summarizes the recent strategies explored to inhibit biofilm formation, with special focus on those targeting quorum sensing.
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In the last decades, global food supply chains had to deal with the increasing awareness of the stakeholders and consumers about safety, quality, and sustainability. In order to address these new challenges for food supply chain systems, an integrated approach to design, control, and optimize product life cycle is required. Therefore, it is essential to introduce new models, methods, and decision-support platforms tailored to perishable products. This thesis aims to provide novel practice-ready decision-support models and methods to optimize the logistics of food items with an integrated and interdisciplinary approach. It proposes a comprehensive review of the main peculiarities of perishable products and the environmental stresses accelerating their quality decay. Then, it focuses on top-down strategies to optimize the supply chain system from the strategical to the operational decision level. Based on the criticality of the environmental conditions, the dissertation evaluates the main long-term logistics investment strategies to preserve products quality. Several models and methods are proposed to optimize the logistics decisions to enhance the sustainability of the supply chain system while guaranteeing adequate food preservation. The models and methods proposed in this dissertation promote a climate-driven approach integrating climate conditions and their consequences on the quality decay of products in innovative models supporting the logistics decisions. Given the uncertain nature of the environmental stresses affecting the product life cycle, an original stochastic model and solving method are proposed to support practitioners in controlling and optimizing the supply chain systems when facing uncertain scenarios. The application of the proposed decision-support methods to real case studies proved their effectiveness in increasing the sustainability of the perishable product life cycle. The dissertation also presents an industry application of a global food supply chain system, further demonstrating how the proposed models and tools can be integrated to provide significant savings and sustainability improvements.
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The increasing attention to environmental issues of recent times encourages us to find new methods for the production of energy from renewable sources, and to improve existing ones, increasing their energy yield. Most of the waste and agricultural residues, with a high content of lignin and non-hydrolysable polymers, cannot be effectively transformed into biofuels with existing technology. The purpose of the study was to develop a new thermochemical/ biological process (named Py-AD) for the valorization of scarcely biodegradable substances. A complete continuous prototype was design built and run for 1 year. This consists into a slow pyrolysis system coupled with two sequential digesters and showed to produce a clean pyrobiogas (a biogas with significant amount of C2-C3 hydrocarbons and residual CO/H2), biochar and bio-oil. Py-AD yielded 31.7% w/w biochar 32.5% w/w oil and 24.8% w/w pyrobiogas. The oil condensate obtained was fractionated in its aqueous and organic fraction (87% and 13% respectively). Subsequently, the anaerobic digestion of aqueous fraction was tested in a UASB reactor, for 180 days, in increasing organic loading rate (OLR). The maximum convertible concentration without undergoing instability phenomena and with complete degradation of pyrogenic chemicals was 1.25 gCOD L digester-1 d-1. The final yield of biomethane was equal to 40% of the theoretical yield and with a noticeable additional production equal to 20% of volatile fatty acids. The final results confirm that anaerobic digestion can be used as a useful tool for cleaning of slow pyrolysis products (both gas and condensable fraction) and the obtaining of relatively clean pyrobiogas that could be directly used in internal combustion engine.
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The purpose of this thesis work was the valorization of the main by-products obtained from olive oil production chain (wastewater and pomace) and their utilization in innovative food formulation. In the first part of the thesis, an olive mill wastewater extract rich in phenols were used in the formulation of 3 innovative meat products: beef hamburgers, cooked ham and würstels. These studies confirms that olive mill wastewaters extract rich in phenols could be an alternative for the reduction/total replacement of additives (i.e., nitrites) in ground and cooked meat preparations, which would promote the formulation of healthier clean label products and improve the sustainability of the olive oil industry with a circular economy approach, by further valorizing this olive by-product. In the second part of the thesis, the lipid composition and oxidative stability of a spreadable product obtained from a fermented and biologically de-bittered olive pomace, was assessed during a shelf-life study. This study confirmed that olive pomace represents an excellent ingredient for the formulation of functional foods In the third and last part of the thesis, carried out at the Universidad de Navarra (Pamplona, Spain), during a period abroad (3 months), three extracts obtained from purification of olive mill wastewaters, were subjected to in-vitro digestion and characterized. From the analysis of the three phenolic extracts, it emerged that the most promising extract to be used in the food field is the spry-dried one. Thanks to its formulation containing maltodextrins it manages to maintain its antioxidant capacity even after being underwent to in-vitro digestion. This thesis work is a part of the PRIN 2015 project (PROT: 20152LFKAT) "Olive phenols as multifunctional bioactives for healthier food: evaluation of simplified formulation to obtain safe meat products and new foods with higher functionality", coordinated by University of Perugia.
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Pathogenic fungi are responsible for vine diseases affecting the grapevine yield and the organoleptic quality of the final wine products. Using of biocontrol agents can represent a sustainable alternative to the use of synthetic fungicides whose intense use can have negative effects on the ecosystem and cause increase resistant pathogen population to synthetic agents. The principal aim of my PhD thesis was the isolation and characterization of new yeast strains and Bacillus subtilis SV108 as biocontrol agent and the comprehension of the mechanism of their antimicrobial action. Accordingly, twenty wild yeast and one selected bacterium isolated among 62 samples, isolated from different Italian and Malaysian regions and molecularly identified, were evaluated in a preliminary screening test on agar. Results showed the highest effects on inhibiting mycelial growth by Starmerella bacillaris FE08.05, Metschnikowia pulcherrima GP8 and Hanseniaspora uvarum GM19. On the other side, Bacillus subtilis SV108 showed the ability of inhibit the mycelial growth of selected fungi by producing antimicrobial compounds on Malt Extract Broth medium recovered by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and identified by electrospray ionization (ESI) tandem mass spectrometer Triple TOF 5600. Moreover, in order to analyze the volatile fraction of compounds, the quantitative analysis of the VOCs profiles was performed by GC/MS/SPME. The analysis highlighted the presence of isoamyl and phenylethyl alcohols and an overall higher presence of low-chain fatty acids and volatile ethyl esters. All the data collected suggest that the tested yeasts, found among the epiphytic microbiota associated with grape berries, can be potentially effective for the biological control of pathogenic moulds. On the other hand, the proteomic study conducted on B. subtilis SV108 revealed that there are two cyclic antifungal peptides which can explain the antimicrobial effect of Bacillus subtilis SV108 acting as biocontrol agent against fungal pathogens in grapevine.
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Società Azionaria Prodotti Asfaltico Bituminosi Affini (S.A.P.A.B.A. s.r.l.) is an asphalt/aggregate production plant located in Bologna, Italy. The resulting dirt and mud from the washing process is stored at specific sedimentation lakes close to the plant and are referred to as waste silt. The initiative and motivation of the current research follows the 12th objective of the sustainable development goals proposed by the United Nations. As a result, the overall aim of the current study was to reduce the impact of waste mineral fillers through recycling in new paving solutions. Considering three paving types of cement-bound, geopolymer-bound and asphalt pavements the following objectives were set: 1) To investigate the possibility of recycling waste silt in cement-bound paving solution; 2) To explore the feasibility of producing geopolymer-bound paving solutions containing waste silt; 3) To study the potential of using waste silt as fillers in different asphalt pavements. The first objective was achieved by utilizing waste silt into cement-bound materials. For this purpose, the by-product was introduced to cement mortars and was partially replaced (20%) with the natural sand. Moreover, statistical models were used to produce concrete paving blocks. The second objective was pursued by studying the feasibility of using the waste silt as a filler in geopolymer cement products. Following a comprehensive review, the silt was thermally calcined and used as filler in geopolymer cement and paving blocks. The third objective was achieved by evaluating the rheological and mechanical performance of hot mix, porous and semi-flexible asphalt containing waste silt. The limestone filler of a hot mix asphalt was replaced with thermally and untreated waste silt. To sum up, different paving blocks and asphalt pavements mixtures containing waste silt were proposed that presented acceptable performance when compared to different national and European standards.