2,516 research outputs found

    Pregnancy and cardiac disease

    Get PDF

    Pregnancy and cardiac disease

    Get PDF

    Raman Spectroscopy Techniques for the Detection and Management of Breast Cancer

    Get PDF
    Breast cancer has recently become the most common cancer worldwide, and with increased incidence, there is increased pressure on health services to diagnose and treat many more patients. Mortality and survival rates for this particular disease are better than other cancer types, and part of this is due to the facilitation of early diagnosis provided by screening programmes, including the National Health Service breast screening programme in the UK. Despite the benefits of the programme, some patients undergo negative experiences in the form of false negative mammograms, overdiagnosis and subsequent overtreatment, and even a small number of cancers are induced by the use of ionising radiation. In addition to this, false positive mammograms cause a large number of unnecessary biopsies, which means significant costs, both financially and in terms of clinicians' time, and discourages patients from attending further screening. Improvement in areas of the treatment pathway is also needed. Surgery is usually the first line of treatment for early breast cancer, with breast conserving surgery being the preferred option compared to mastectomy. This type of operation achieves the same outcome as mastectomy - removal of the tumour - while allowing the patient to retain the majority of their normal breast tissue for improved aesthetic and psychological results. Yet, re-excision operations are often required when clear margins are not achieved, i.e. not all of the tumour is removed. This again has implications on cost and time, and increases the risk to the patient through additional surgery. Currently lacking in both the screening and surgical contexts is the ability to discern specific chemicals present in the breast tissue being assessed/removed. Specifically relevant to mammography is the presence of calcifications, the chemistry of which holds information indicative of pathology that cannot be accessed through x-rays. In addition, the chemical composition of breast tumour tissue has been shown to be different to normal tissue in a variety of ways, with one particular difference being a significant increase in water content. Raman spectroscopy is a rapid, non-ionising, non-destructive technique based on light scattering. It has been proven to discern between chemical types of calcification and subtleties within their spectra that indicate the malignancy status of the surrounding tissue, and differentiate between cancerous and normal breast tissue based on the relative water contents. Furthermore, this thesis presents work aimed at exploring deep Raman techniques to probe breast calcifications at depth within tissue, and using a high wavenumber Raman probe to discriminate tumour from normal tissue predominantly via changes in tissue water content. The ability of transmission Raman spectroscopy to detect different masses and distributions of calcified powder inclusions within tissue phantoms was tested, as well as elucidating a signal profile of a similar inclusion through a tissue phantom of clinically relevant thickness. The technique was then applied to the measurement of clinically active samples of bulk breast tissue from informed and consented patients to try to measure calcifications. Ex vivo specimens were also measured with a high wavenumber Raman probe, which found significant differences between tumour and normal tissue, largely due to water content, resulting in a classification model that achieved 77.1% sensitivity and 90.8% specificity. While calcifications were harder to detect in the ex vivo specimens, promising results were still achieved, potentially indicating a much more widespread influence of calcification in breast tissue, and to obtain useful signal from bulk human tissue is encouraging in itself. Consequently, this work demonstrates the potential value of both deep Raman techniques and high wavenumber Raman for future breast screening and tumour margin assessment methods

    LIPIcs, Volume 251, ITCS 2023, Complete Volume

    Get PDF
    LIPIcs, Volume 251, ITCS 2023, Complete Volum

    Application of Heterojunction Ni-Sb-SnO₂ Anodes for Electrochemical Water Treatment

    Get PDF
    Clean water supply and adequate sanitation services are critical for public health as well as for food production. Small-scale decentralized treatment represents an attractive alternative that can provide necessary water treatment in many parts of the developing world where centralized wastewater treatment facilities are not practical owing to financial, geographical, or political constraints. Electrochemical oxidation (EO) is a suitable technique for decentralized treatment settings since it does not require the addition of auxiliary chemicals and offers fast reaction kinetics and modular treatment capacity. EO is considered a versatile technology since it can degrade a wide array of contaminants and inactivate waterborne pathogens. The chemical composition of the anode, where EO takes place, is a key factor that controls reactive species production and thus treatment efficiency and energy consumption. Ideal anodes for wastewater treatment should have high overpotential for oxygen evolution (“nonactive” anodes) and favor complete organics oxidation through direct electron transfer and/or reactions with potent oxidants such as hydroxyl radical and ozone. Common nonactive anodes including antimony-doped tin oxide (Sb-SnO₂), lead oxide (PbO₂), and boron-doped diamond (BDD) have attracted wide research interests. The work presented in this thesis centered around a newly designed heterojunction Ni-Sb-SnO₂2-based anode (NAT/AT) and its various applications in decentralized water and wastewater treatment. Direct treatment using NAT/AT has proved to be efficient for chemical oxygen demand removal, trace organic compound degradation, and microbial disinfection. Detailed investigation into pharmaceutical degradation kinetics and transformation products further established NAT/AT as a potential treatment alternative for the control of pharmaceuticals and their metabolites in hospital wastewaters. NAT/AT is also capable of synthesizing ferrates (e.g., FeO₄²⁻) in circumneutral conditions, the high oxidation state iron species that represents another group of powerful oxidants well-suited for decentralized treatment purposes. In an additional effort to tackle high concentrations of ammonium often present in latrine wastewaters, functionalized metal-organic framework (MOF), a class of materials featuring high porosity, abundant active sites, and highly tunable physical and chemical properties, was used to recover the ammonium nitrogen. Various modifications of MOF-808, a highly water stable MOF, were designed and synthesized to achieve urea hydrolysis, ammonium capture, and real-time ammonium sensing in sequence. In combination, the described works provide a powerful toolkit that can be used in treating various waste streams before discharge and/or reuse

    A critical review on latest innovations and future challenges of electrochemical technology for the abatement of organics in water

    Get PDF
    Updated water directives and ambitious targets like the United Nations’ Sustainable Development Goals (SDGs) have emerged in the last decade to tackle water scarcity and contamination. Although numerous strategies have been developed to remove water pollutants, it is still necessary to enhance their effectiveness against toxic and biorefractory organic molecules. Comprehensive reviews have highlighted the appealing features of the electrochemical technologies, but much progress has been made in recent years. In this timely review, a critical discussion on latest innovations and perspectives of the most promising electrochemical tools for wastewater treatment is presented. The work describes the performance of electrocatalytic anodes for direct electrochemical oxidation, the oxidation mediated by electrogenerated active chlorine, the electrocatalytic reduction as well as coupled approaches for synchronous anodic and cathodic processes combined with homogeneous and heterogeneous catalysis. The last section is devoted to the assessment of scale-up issues and the increase in the technology readiness level

    Reticular Metal-Organic Frameworks for sustainable applications

    Get PDF
    La presente tesis doctoral se ha realizado mediante compendio de publicaciones en cumplimiento con las normativas establecidas por la Universidad de Valencia, según lo dispuesto en el reglamento ACGUV 266/2011 referente al depósito, evaluación y defensa de tesis doctorales, con la última actualización correspondiente al 31 de Octubre de 2017. El trabajo se encuentra estructurado en tres capitulos principales, seguidos de un capítulo final que engloba las conclusiones obtenidas a partir de los resultados de la investigación, así como los planes y perspectivas para trabajos futuros. El capitulo 1 proporciona un contexto general sobre los materiales abordados en esta tesis: Metal-Organic Frameworks (MOFs) basados en oxamidato. Se presenta una breve revision histórica que abarca desde los orígenes de la química de coordinación hasta los MOFs, destacando la importancia de la química reticular y el creciente interés en el campo de los MOFs. También se describen las metodologías sintéticas y de caracterización más comunes, junto con las propiedades físico-químicas más destacadas de los MOFs. Entre estas propiedades, destacan su alta porosidad y cristalinidad, lo que les permite presentar grandes áreas superficiales y volúmenes de poro, y ser caracterizados mediante técnicas de difracción de rayos X. Además, se resalta la interesante química host-guest de estos materiales, que puede ser controlada a través del tamaño, forma y reactividad de los poros. Esto los convierte en candidatos ideales para preparar materiales multifuncionales con aplicaciones endiversas áreas tecnológicas, como se describe con ejemplos representativos en detalle. En este capitulo se enfatiza especialmente el papel clave de los MOFs Multivariantes (MTV-MOFs) debido a sus propiedades y aplicaciones únicas. Finalmente, se describe el trabajo previo relacionado realizado dentro de mi grupo de investigación, justificando la elección de la estrategia sintética utilizada y demostrando las ventajas que posee el uso de ligandos basados en oxamidato derivados de aminoácidos para obtener nuevos materiales quirales, estables en agua y con una rica diversidad estructural. En los capítulos 2 y 3, se presentan los principales resultados obtenidos de esta tesis, los cuales han sido publicados en importantes revistas científicas. En el capítulo 2, se persiguieron dos objetivos. En primer lugar, se estudió el cambio en la reactividad de los catalizadores organometálicos con el fin de entender la naturaleza de las especies catalíticamente activas y los mecanismos de reacción, aprovechando los efectos de restricción estérica inducidos por el MOF. En segundo lugar, se exploraron los efectos de la funcionalización de los canales con más de un residuo de aminoácido distinto en reacciones catalíticas de relevancia industrial, inspirados en los centros activos de las enzimas, donde diferentes funcionalidades orgánicas pueden actuar sinérgicamente para mejorar la eficiencia catalítica. En el capítulo 3, se aprovechó la rica química host-guest de estos MOFs para la captura eficiente de algunos de los contaminantes orgánicos más comunes encontrados en ambientes acuáticos, como tintes orgánicos e insecticidas neonicotinoides (NEOs). En ambos capítulos se investigó el efecto de diferentes grupos funcionales para introducir nuevas o mejoradas propiedades físicas, así como su uso como catalizadores heterogéneos y para la captura de contaminantes en agua, respectivamente. Se destacó la importancia de la alta cristalinidad de este tipo de materiales para descubrir lo que sucede dentro de los poros a través de la difracción de rayos X de monocristal (SCXRD), ya que las estructuras cristalinas de los agregados host-guest proporcionaron evidencia de las interacciones sinérgicas entre los diferentes grupos funcionales de los MOFs y los huéspedes, permitiéndo comprender las propiedades excepcionales de estos materiales. En general, se llevaron a cabo los siguientes pasos: • Diseño y síntesis de proligandos basados en oxamidato derivados de aminoácidos naturales enantiopuros capaces de coordinar Cu(II) y producir los precursores de dicobre(II) trans-oxamidato. • Síntesis de MOFs y MTV-MOFs utilizando diferentes precursores de oxamidato, tanto en polvo como en monocristales. • Estudio de las propiedades de los MOFs y MTV-MOFs obtenidos, analizando el efecto de la presencia de diferentes grupos funcionales para mejorar sus propiedades físicas o introducir nuevas funcionalidades. • Estudio de su uso para la captura de contaminantes orgánicos en agua y como catalizadores heterogéneos, ya sea mediante la síntesis de MOFs catalíticamente activos que contienen complejos metálicos utilizando Métodos Post-Sintéticos (PSMs) o mediante su uso como plantillas para catalizar reacciones. Los materiales obtenidos se caracterizaron mediante técnicas como espectroscopía infrarroja (IR), resonancia magnética nuclear (RMN), análisis termogravimétrico (TGA), difracción de rayos X de polvo (PXRD), adsorción de N2 y CO2 y microscopía electrónica de barrido (SEM). Sin embargo, la resolución de las estructuras cristalinas mediante SCXRD, así como los estudios de la actividad catalítica y los métodos analíticos de extracción en fase sólida (SPE) fueron realizados por el resto de coautores.The main objective of this thesis is to design and synthesize new multifunctional Metal-Organic Frameworks (MOFs) and multivariate MOFs (MTV-MOFs) for two purposes: first, to reduce the level of pollutants in aquatic ecosystems to meet the acceptable standards set by the World Health Organization (WHO), and second, to use them as heterogeneous catalysts to carry out reactions in a more sustainable way. To achieve this objective, functionalized oxamidato derivatives were used to build high-dimensional MOFs through the metalloligand strategy. In particular, dinuclear CuII complexes were employed as metalloligands to assemble heterobimetallic three- dimensional (3D) MOFs with functional pores decorated with amino acid residues, which provide flexibility to the framework, thereby influencing the properties and potential applications of these materials. In general, the following steps were carried out: • Design and synthesis of oxamidato-based proligands derived from enantiopure natural amino acids that can coordinate Cu(II) to yield trans-oxamidato dicopper(II) precursors. • Synthesis of water-stable oxamidato-based MOFs and MTV-MOFs with different oxamidato precursors, either in polycrystalline powder or in single crystals. • Study the properties of the MOFs and MTV-MOFs obtained. In particular, investigating the effect of different functional groups to introduce new or improved physical properties. • Study of their use for capturing pollutants in water and as heterogeneous catalysts, either by synthesizing catalytically active MOFs containing metal complexes using Post-Synthetic Methodologies (PSMs) or by using them as templates to catalyze reactions. The physical characterization of the obtained materials has been performed using infrared spectroscopy (IR), nuclear magnetic resonance (NMR), termogravimetric analysis (TGA), powder X-ray diffraction (PXRD), N2 and CO2 adsorption, and scanning electron microscopy (SEM). However, the resolution of crystal structures through single cristal X-ray diffraction (SCXRD), as well as studies of catalytic activity and solid-phase extraction (SPE), were carried out in collaboration with other research groups. For clarity, the thesis is divided into the following sections: Chapter 1 provides a general context to the materials developed during this thesis, that is, oxamidato-based MOFs. In this chapter, an overview entitled “From Coordination Chemistry to Reticular Chemistry” is presented, which focuses on the increasing interest in the field of MOFs. The most common synthetic and characterization methodologies are also briefly described, and the most remarkable properties of MOFs are discussed, with representative examples described in more detail. Additionally, a particular and emerging type of MOF, the so-called Multivariate MOFs (MTV-MOFs), is highlighted, as it shows unique properties and applications and has played a key role in this thesis. Finally, the related previous work developed within my research group is also described, emphasizing the advantages of using oxamidato-based ligands derived from amino acids to build up 3D MOFs through the metalloligand approach. Chapters 2 and 3 present the main results obtained during this thesis, which have been collected and published in some important scientific journals. In chapter 2, two objectives were pursued. Firstly, the change in reactivity in organometallic catalysts was studied to reveal the nature of catalytically active species and reaction mechanisms, taking advantage of the steric constraint effects induced by the MOF network. Secondly, drawing inspiration from the active centers of enzymes, where different organic functionalities can act synergetically, the effects on catalytic reactions of industrialrelevance when functional channels are decorated with more than one distinct amino acid residues were explored. In chapter 3, the rich host-guest chemistry of these MOFs was exploited for the efficient capture of some of the most common organic contaminants found in aquatic environments, such as organic dyes and neonicotinoids insecticides (NEOs). The crystal structures of the host-guest aggregates provided evidence of the synergistic interactions between the different functional groups of the MOFs and the guest contaminants, allowing us to understand the exceptional capture properties of these materials. Finally, chapter 4 presents the conclusions, as well as plans for future work and perspectives

    ETHICAL EVALUATION IN WILDLIFE CONSERVATION: ART, ANIMAL-VISITOR INTERACTIONS AND EMERGENCIES IN WILDLIFE MANAGEMENT AND CONSERVATION

    Get PDF
    Nell’attuale crisi globale della biodiversità è sempre più cruciale valutare le questioni eticamente rilevanti e considerare la natura pluralistica della conservazione della biodiversità. L'etica della conservazione fornisce strumenti per eseguire tali valutazioni e assistere nei processi decisionali. La tesi di questo dottorato di ricerca presenta studi in cui vengono utilizzati strumenti per eseguire valutazioni etiche e multidisciplinari per valutare progetti di conservazione e gestione della fauna selvatica. Pertanto, questo lavoro di dottorato mostra tre diverse aree di applicazione dell'etica della conservazione: Conservation ART, le interazioni animale-visitatore e le sfide nella gestione della fauna selvatica durante l'emergenza COVID-19. Nella prima sezione, la valutazione etica è stata applicata nel contesto del progetto BioRescue, in cui le tecnologie di riproduzione assistita (ART) sono utilizzate nello sforzo di salvare il rinoceronte bianco settentrionale (Ceratotherium simum cottoni) dall’estinzione. Le tecnologie di riproduzione assistita possono fare la differenza nella conservazione della biodiversità, ma la loro applicazione può sollevare questioni eticamente rilevanti che necessitano di essere affrontate. Pertanto, in primo luogo, è stata utilizzata la Matrice Etica (EM) per presentare un quadro per l'analisi etica dell'applicazione delle procedure ART nella conservazione. L'EM, anche se specificamente costruita attorno alle procedure di prelievo di ovociti (OPU) effettuate su rinoceronti bianchi, ha permesso di raggruppare i fattori eticamente rilevanti, identificare e valutare complessi scenari morali in cui diversi bisogni, interessi e preoccupazioni etiche possono entrare in conflitto e fornire infine un modello per la valutazione delle procedure ART in progetti che coinvolgono altre specie in via di estinzione. In seguito, viene presentato un nuovo strumento di valutazione etica (ETHAS) specificamente sviluppato per valutare l’applicazione delle procedure ART in conservazione, e vengono illustrati i risultati delle prime applicazioni. ETHAS, con le sue due liste checklist che lo compongono, permette di effettuare un'autovalutazione integrata, multilivello e standardizzata della procedura in esame, generando una classifica di accettabilità etica e consentendo l'attuazione di misure per affrontare o gestire eventuali problemi in anticipo. ETHAS, specificatamente customizzato per l'OPU e le procedure di fecondazione in vitro eseguite sul rinoceronte bianco settentrionale, hanno permesso di garantire un elevato standard delle procedure, migliorare alcuni aspetti della comunicazione tra i partner del progetto e migliorare lo strumento stesso al fine di essere applicato nel prossimo futuro ad altri contesti in cui le ART vengono utilizzate per la conservazione di altre specie di mammiferi. Nell'ultimo studio presentato nella prima sezione, la matrice etica, l'albero decisionale e il cubo di Bateson sono stati adattati per assistere nell'analisi etica di un complesso scenario relativo alla decisione se continuare o meno la raccolta di biomateriale sul più anziano dei due rimanenti rinoceronti bianchi settentrionali, Najin. Strutturando questi strumenti per implementare le diverse dimensioni di valore (ambientale, sociale e benessere animale) coinvolte nell'etica della conservazione, è stato possibile raccogliere pro e contro, confrontare le diverse opzioni e stabilire una soglia di accettabilità etica. L'applicazione degli strumenti è stata fondamentale per strutturare il processo decisionale e aiutare a raggiungere la decisione condivisa, ragionata e trasparente di sospendere Najin da qualsiasi ulteriore procedura di prelievo di ovociti. L'etica della conservazione può anche aiutare ad esplorare le questioni etiche riguardanti la gestione della fauna selvatica durante le interazioni animale-visitatore (AVI) che si svolgono nelle strutture zoologiche. A questo proposito, la Sezione 2In the global biodiversity crisis, it is increasingly crucial to evaluate ethically relevant issues and consider the pluralistic nature of biodiversity conservation. Conservation ethics provides tools to perform such evaluation and assist in the decision-making processes. This Ph.D. thesis presents studies in which ethical tools are used to perform ethical evaluation and multidisciplinary assessments to approach conservation projects and wildlife management. Three different areas of application of conservation ethics are discussed: Conservation ART, animal-visitor interactions, and challenges in wildlife management during the COVID-19 emergency. In the first area, ethical evaluation has been applied in the context of the BioRescue project, an international project in which assisted reproductive technologies (ARTs) are used in the effort to save the endangered northern white rhinoceros (Ceratotherium simum cottoni). Assisted reproductive technologies can make a difference in biodiversity conservation, but their application can raise ethical issues that need to be addressed. Therefore, firstly, an Ethical Matrix (EM) has been used to present a framework for the ethical analysis of the application of ART procedures in conservation. The EM, specifically built around the ovum pick-up (OPU) procedures carried out on white rhinoceros, allowed to collect ethically relevant factors to identify issues and value conflicts, evaluates complex moral scenarios where different needs, interests, and ethical concerns may conflict, and provides a template for the assessment of ART procedures in projects involving endangered species. Therefore, a new ethical evaluation tool (ETHAS) specifically developed to assess ART procedures in conservation is presented, and the first application results are reported. ETHAS, with its two checklists, provides an integrated, multilevel, and standardized self-assessment of the procedure under scrutiny, generating an ethical acceptability ranking and allowing for implementing measures to address or manage issues beforehand. ETHAS customized for OPU and in vitro fertilization procedures performed on the northern white rhinoceros allowed for ensuring a high standard of procedures, improving some aspects of the communication among the projects’ partners, and improving the tool itself, in order to be applied in the near future to other contexts in which ARTs are applied for the conservation of other mammal species. Finally, in the last study presented in the first section, the ethical matrix, decision tree, and Bateson’s cube have been adapted to assist in the ethical analysis of a complex conservation scenarios relative to the decision regarding whether or not to continue collecting biomaterial on the oldest of the two remaining northern white rhinoceroses. By structuring these tools to implement the different value dimensions (environmental, social, and animal welfare) involved in conservation ethics, it has been possible to gather ethical pros and cons, compare the different options at stake, and establish a threshold of ethical acceptability. The application of the tools was pivotal in structuring the decision-making process and helping reach the shared, reasoned, and the transparent decision to discontinue Najin from any further oocyte collection procedures. Conservation ethics can also assist in exploring the ethical issues concerning wildlife management during animal-visitor interactions (AVI). In this regard, Section 2 of this thesis presents studies concerning AVIs. Firstly, a participatory process has been followed with an Ethical Matrix to explore welfare and management issues related to AVIs. The inclusion of the stakeholders' perspectives allowed to record all the value demands concerning AVI and provide a map of the ethically relevant aspects involved. This map shows how the ethical acceptability of AVIs is linked to different relevant issues like animal welfare, education, and biodiversit
    corecore