6 research outputs found

    New Metal Complexes and Metal-Organic Frameworks (MOFs) with Potential Biological Applications.

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    As a cornerstone of synthetic chemistry, the coordination of organic ligands to ions/clusters has been used to prepare many types of materials, including metal complexes, metal–organic polyhedral, porous coordination polymers, porous coordination networks, and metal–organic frameworks (MOFs) [1]. These metal–organic materials are assembled by metal coordination, hydrogen bonding, electrostatic interactions or – stacking [2], exhibiting tunable structures, compositions and properties. Therefore, they are considered as promising candidates in the fields of catalysis, gas adsorption and separation, sensors, functional devices, etc [3]. Notably, biomedical applications have greatly benefited from the progress made by these metal–organic materials in the fields of diagnosis, monitoring, and therapy. Some of the biomedical applications of metal–organic materials include biosensors, biocatalysis, bioimaging, drug delivery, anticancer, antibacterial, and wound healing. This part mainly focuses on different types of metal complexes and MOFs for biomedical applications, specifically, for antibacterial and biosensing applications

    Élaboration de quarts de travail robustes aux perturbations de courte durĂ©e

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    RÉSUMÉ : Le problĂšme de la conception d’horaires d’employĂ©s est capital dans de nombreuses structures : dans les grandes surfaces, dans les hĂŽpitaux, dans la vente au dĂ©tail en gĂ©nĂ©ral par exemple. De nombreuses Ă©tudes ont portĂ© sur ce sujet. Nous nous intĂ©ressons ici plus prĂ©cisĂ©ment au caractĂšre robuste des solutions par rapport aux perturbations de petite envergure. Nous souhaitons que lors d’un imprĂ©vu de la demande de petite durĂ©e, ou lors d’un retard d’employĂ©, il soit plus facile de s’adapter grĂące Ă  des horaires plus flexibles. Nous nous intĂ©ressons en particulier Ă  deux types de perturbations diffĂ©rentes : des augmentations de la demande sur des durĂ©es variant de quinze minutes Ă  une heure, et des retards d’employĂ©s de l’ordre de la demie heure. Au cours de notre Ă©tude, nous utilisons des donnĂ©es oĂč nous sont fournies les courbes de demande selon les diffĂ©rentes activitĂ©s considĂ©rĂ©es ainsi qu’un nombre Ă©levĂ© de quarts potentiels pour chacun des employĂ©s. Plusieurs modĂšles basĂ©s sur des programmes mathĂ©matiques linĂ©aires en nombres entiers de sĂ©lection de quarts sont mis en avant, et nous effectuons des simulations sur trois de ces modĂšles. Nous travaillons sur un horizon d’une semaine, en dĂ©composant le temps en pĂ©riodes d’une quinzaine de minutes, en considĂ©rant des employĂ©s avec des qualifications qui doivent satisfaire les courbes de demande des diffĂ©rentes activitĂ©s considĂ©rĂ©es. Les deux premiers modĂšles testĂ©s portent sur la robustesse face aux perturbations de la demande. L’un d’entre eux consiste Ă  diminuer artificiellement le coĂ»t des quarts pouvant ĂȘtre utilisĂ©s pour absorber certaines perturbations prĂ©vues, tandis que l’autre prĂ©sente une approche basĂ©e sur des sous-couvertures potentielles : on considĂšre les perturbations comme une demande potentielle et chacun des quarts comprend - ou non - un travail potentiel, c’est-Ă - dire un ensemble de pĂ©riodes oĂč l’employĂ© peut rester en plus de son quart si la nĂ©cessitĂ© se prĂ©sente. On constate que ces deux mĂ©thodes ont des rĂ©sultats relativement similaires, mais chacune est plus efficace dans certaines situations. Dans un second temps, nous Ă©tudions une modĂ©lisation permettant de minimiser le coĂ»t espĂ©rĂ© des perturbations liĂ©es au retard des employĂ©s. Pour ce faire, nous favorisons le dĂ©but de quarts aux endroits oĂč un autre quart finit. Cette mĂ©thode ne prĂ©sente cependant que de petites amĂ©liorations au niveau du coĂ»t final sur un nombre limitĂ© d’instances. Ces mĂ©thodes prĂ©sentent donc dans leur ensemble des rĂ©sultats plutĂŽt prometteurs qui mĂ©riteraient d’ĂȘtre Ă©tudiĂ©s plus en profondeur avec une Ă©tude complĂ©mentaire sur la construction des quarts elle-mĂȘme. Cela permettrait d’avoir un impact plus consĂ©quent sur la flexibilitĂ© des horaires choisis.----------ABSTRACT : Staff scheduling has become more and more important in today’s industries, where the priorities are more cost-oriented than before and where customer service is more predominant than ever. A lot of studies have been about improving performance in that area. This paper, on staff-scheduling, focuses on robustness to small perturbations. Our aim is to create flexibility in the schedules to allow us to adapt to perturbations, whether it be a demand perturbation or a late employee. The two types of perturbations we take into account are unpredicted spikes in the demand of a duration between fifteen minutes and one hour, and employees being late, typically by thirty minutes. The data we are given are the demand curves of possibly several activities, and the many potential shifts for each employee. We study several ways of selecting shifts amongst the ones that we are given, all of them based on integer linear programming, and test three of those through simulations. In the first method, we artificially lower the cost of shifts that might allow us to adapt to some perturbations. In the second, we use potential demand to model the perturbations, potential working for when an employee working a shift can fill in for an activity and potential undercover to take the costs into account. These two methods have quite similar satisfying results, even though each is more effective in some cases. After dwelling on how to adapt to perturbations linked to the demand, we study employee lateness. To reduce its cost, we try to favour groups of shifts where several start at the same time index as another shift ends. That way, if an employee is late, it is easy to ask overtime of an employee that was about to leave. This approach only allows some small improvement on the overall cost, and solely on a limited number of instances. Overall, these different methods show interesting results, that might improve significantly with a study that delves into adapting shift generation. It may improve significantly the flexibility of staff schedules

    A critical evaluation of the use of the moss technique to monitor air pollution

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    Passive biomonitoring with terrestrial mosses, i.e. the “moss biomonitoring technique”, constitutes a useful tool for the study of the atmospheric deposition of heavy metals. However, it has limitations, some of which have been deeply assessed in this doctoral thesis. Thus, the temporal variability of the concentrations of several nutrients and pollutants in Pseudoscleropodium purum and the effect of growth on the concentrations of elements in segments of different ages of P. purum have been assessed (Chapters I and II respectively). Besides, the possible development of differences in the accumulation capacities of mosses that have grown in environments under different levels of pollution (Chapter III), and the relationship between the concentrations of several heavy metals in mosses and in bulk deposition (Chapters IV, V and VI), have also been discussed. Finally, despite the limitations found in the first part of this thesis (Chapters I to VI), it has been demonstrated that the technique enables researchers to distinguish between contaminated and uncontaminated sites, to identify small scale pollution sources, and to map spatial and temporal patterns of the atmospheric heavy metal deposition However, its application in environmental policy making is still limited due to the lack of a reliable, scientifically rigorous and homogenized protocol for the technique. Therefore a critical review of the available literature on passive biomonitoring with terrestrial mosses has been made (Chapter VII) in order to propose a protocol, as harmonised as possible, based on the results of the methodological studies published to date. Therefore, it can be concluded in the basis of all the results presented in this thesis, together with previously reported findings, that passive biomonitoring studies with terrestrial mosses provide qualitative and/or semi-quantitative rather than quantitative information. Interpretation of the results of this type of study must therefore be reconsidered; however, this does not mean that the information obtained is not useful. Such reconsideration, together with true harmonization of the technique (by publication of a protocol exclusively based on scientific criteria), should bridge the gap between the scientific application of the technique and its application in environmental policy making

    EVALUATION OF EFFECTS OF NEW ANTIFOULING SYSTEMS, ALTERNATIVE TO ORGANOTIN COMPOUNDS, ON BENTHIC MARINE INVERTEBRATES AT ECOSYSTEM, ORGANISMAL AND CELLULAR LEVEL

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    Marine biofouling on anthropic submerged substrata is associated with major ecological and socioeconomic impacts worldwide. The most widely used antifouling systems are chemical ones represented by paints with a biocide, to which booster substances can be added. The latter are highly toxic chemical substances from agriculture (herbicides, fungicides, acaricides, wood preservatives) and pharmaceutical industry (bactericides, fungicides), these cause various ecological problems due to disruptive effects provoked on non-target organisms and depletion of coastal biocoenoses. From 2001, the paints including organotin compounds (TBT and TPT), which had the best performance and were used worldwide for decades, were banned by International Maritime Organization (IMO) after the discovery of their severe impact on the oyster farms. As a consequence of the restrictions on the use of organotin-based paints, finding new antifouling systems has become a primary necessity. Therefore, the research was devoted to new eco-friendly formulations. Regarding Physical antifouling systems have been recently introduced in relation to the development of a more environmentally friendly approach rather than the chemical systems. My scholarship has been entirely financed by RESIMIX s.r.l of Brendola, Vicenza (Italy). The university-enterprise collaboration aimed to develop a new eco-friendly paint. More in general, the research program of my PhD thesis focused on the implementation of new antifouling systems with low effects on benthic marine invertebrates. My PhD activity it was been divided in 2 tasks, i.e., chemical antifouling systems and physical antifouling systems. To determine and compare the effects of these new antifouling systems on both target species (ascidians and mussels) and non-target species (clams) the tasks have been developed at three study levels, i.e., ecosystem, individuals, and cells. As regards of chemical antifouling systems I have been investigated the significant differences in the ecological succession of hard-substratum community, by means of a series of biodiversity indexes, during at least one-year exposure to various RESIMIX paints and trade copper-based paints. In addition, a comparative monitoring with trade antifouling paints has been considered together with the effects on settlement and metamorphosis of ascidian larvae and finally, the observation of the mechanisms of action in in vitro immunotoxicity assays on dominant bioindicators in benthic biocoenoses like tunicates, clams and mussels. From these preliminary but significant results about chemical antifouling systems, crucial questions have arisen regarding the continuous indiscriminate introduction of such biocides into the environment. As regards physical antifouling systems I have been considered geotextiles (for protection from coastal erosion), and ultrasound (to prevent biofilm and disturb the larval settlement) reaching interesting results in both the field and the lab, which revealed the till now hidden downside of these systems.Marine biofouling on anthropic submerged substrata is associated with major ecological and socioeconomic impacts worldwide. The most widely used antifouling systems are chemical ones represented by paints with a biocide, to which booster substances can be added. The latter are highly toxic chemical substances from agriculture (herbicides, fungicides, acaricides, wood preservatives) and pharmaceutical industry (bactericides, fungicides), these cause various ecological problems due to disruptive effects provoked on non-target organisms and depletion of coastal biocoenoses. From 2001, the paints including organotin compounds (TBT and TPT), which had the best performance and were used worldwide for decades, were banned by International Maritime Organization (IMO) after the discovery of their severe impact on the oyster farms. As a consequence of the restrictions on the use of organotin-based paints, finding new antifouling systems has become a primary necessity. Therefore, the research was devoted to new eco-friendly formulations. Regarding Physical antifouling systems have been recently introduced in relation to the development of a more environmentally friendly approach rather than the chemical systems. My scholarship has been entirely financed by RESIMIX s.r.l of Brendola, Vicenza (Italy). The university-enterprise collaboration aimed to develop a new eco-friendly paint. More in general, the research program of my PhD thesis focused on the implementation of new antifouling systems with low effects on benthic marine invertebrates. My PhD activity it was been divided in 2 tasks, i.e., chemical antifouling systems and physical antifouling systems. To determine and compare the effects of these new antifouling systems on both target species (ascidians and mussels) and non-target species (clams) the tasks have been developed at three study levels, i.e., ecosystem, individuals, and cells. As regards of chemical antifouling systems I have been investigated the significant differences in the ecological succession of hard-substratum community, by means of a series of biodiversity indexes, during at least one-year exposure to various RESIMIX paints and trade copper-based paints. In addition, a comparative monitoring with trade antifouling paints has been considered together with the effects on settlement and metamorphosis of ascidian larvae and finally, the observation of the mechanisms of action in in vitro immunotoxicity assays on dominant bioindicators in benthic biocoenoses like tunicates, clams and mussels. From these preliminary but significant results about chemical antifouling systems, crucial questions have arisen regarding the continuous indiscriminate introduction of such biocides into the environment. As regards physical antifouling systems I have been considered geotextiles (for protection from coastal erosion), and ultrasound (to prevent biofilm and disturb the larval settlement) reaching interesting results in both the field and the lab, which revealed the till now hidden downside of these systems

    Pollutant Loadings and Impacts from Highway Stormwater Runoff. Volume III: Analytical Investigation and Research Report

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    DTFH61-84-C-00120This is one of four final documents of an investigation dealing with the characterization of stormwater runoff pollutant loads from highways, and the prediction of water quality impacts they cause. Study results are based on monitoring data from 993 individual storm events at 31 highway runoff sites in 11 States. Impact prediction is based on a methodology previously developed and applied to urban runoff and adapted for highway runoff applications. This document describes the procedures used to assemble and analyze the data base and reports the results of these analyses. Included in this document are statistical summaries of the data base, along with a description of procedures to use to predict pollutant discharges from highway sites and the impacts that they will cause to receiving waters

    Selective Ion Exchange Governed by the Irving–Williams Series in K<sub>2</sub>Zn<sub>3</sub>[Fe(CN)<sub>6</sub>]<sub>2</sub> Nanoparticles: Toward a Designer Prodrug for Wilson’s Disease

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    The principle of the Irving–Williams series is applied to the design of a novel prodrug based on K<sub>2</sub>Zn<sub>3</sub>[Fe­(CN)<sub>6</sub>]<sub>2</sub> nanoparticles (ZnPB NPs) for Wilson’s disease (WD), a rare but fatal genetic disorder characterized by the accumulation of excess copper in the liver and other vital organs. The predetermined ion-exchange reaction rather than chelation between ZnPB NPs and copper ions leads to high selectivity of such NPs for copper in the presence of the other endogenous metal ions. Furthermore, ZnPB NPs are highly water-dispersible and noncytotoxic and can be readily internalized by cells to target intracellular copper ions for selective copper detoxification, suggesting their potential application as a new-generation treatment for WD
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