Estudio de la reactividad de complejos de rodio con un silano funcionalizado.

La reacción de silanos funcionalizados de tipo (piridín-2-iloxi)dialquilsilano con complejos de metales de transición en bajo estado de oxidación da lugar a la formación de especies metálicas con ligandos monoaniónicos bidentados de tipo (piridín-2-iloxi)dialquilsililo que presentan una gran versatilidad electrónica y estérica. La interacción metal-silicio en este tipo de compuestos es de gran interés debido a que se trata de una situación de enlace intermedia entre silileno estabilizado por base y sililo. En este TFG se ha estudiado la reactividad de (4-metilpiridin-2-iloxi)dimetilsilano con complejos de rodio (I), en concreto el rodatioborano de 11 vertices tipo nido [8,8-(PPh3)2-nido-8-Rh(SB9H10)] y el compuesto [RhCl(PPh3)3]. En el primer caso se ha obtenido un nuevo complejo caracterizado como un rodatioborano de 11 vertices [8-(PPh3)-8,8-{κ2-Si,Si-(SiNSi)}-nido-8-Rh-(SB9H11)] que presenta un ligando bis-silileno coordinado al rodio, mientras que en la reacción con el catalizador de Wilkinson se ha formado un complejo que ha sido caracterizado como la especie de rodio (III) [Rh(H)(Cl)(κ2-NSi)(PPh3)]. Este complejo ha demostrado tener un comportamiento interesante en disolución. Resultados preliminares sugieren que la formación del ligando bis-silileno en la reacción con el rodatioborano viene determinada por la acción del ligando tioborano [SB9H10].<br /

Metal bioaccumulation in spontaneously grown aquatic macrophytes in Fe-rich substrates of a passive treatment plant for acid mine drainage

Some plants may thrive in polluted environments, accumulating high concentrations of metal/loids in their organs. This study investigates for the first time the bioaccumulation and translocation of metal/loids in Typha domingensis spontaneously grown in extremely Fe-rich substrates (38–44% of Fe2O3) from different components of an acid mine drainage disperse alkaline substrate passive treatment. Most metal/loids were predominantly accumulated in the roots over the aerial parts of the plant, with concentrations of 0.66–9.5% of Fe, 0.02%–0.18% of Al, 55–2589 mg kg-1 of Mg, 51–116 mg kg-1 of Zn, 17–173 mg kg-1 of Cu, and 5.2–50 mg kg-1 of Pb. Bioconcentration factors were mostly below 1 for metal/loids in the studied aneas (e.g. 0.03–0.47 for Cu, 0.10–0.73 for Zn, 0.04–0.28 for As, 0.07–0.55 for Pb, 0.27–055 for Cd, 0.24–0.80 for Ni), which evidences that T. domingensis behaves as an excluder species in these substrates. Translocation factors were below 1 for most elements (e.g. 0.01–0.42 for As, 0.06–0.50 for Pb, 0.24–0.65 for Cd, and 0.10–0.56 for Sb), except for Mn, Ni and in some cases for Tl, Cu and Zn, which indicates limited transfer of metals between plant tissues. Mineralogical and geochemical substrate properties are pointed out as the main factors responsible for the lower bioconcentration and translocation of potentially toxic elements. In addition, the oxidizing conditions existent in the pore water-root system may also limit the mobility of metals from Fe oxides and hydroxysulfates, the main component of the substrate. The formation of a Fe plaque inside the roots may also limit the transfer of metals to the aerial parts. The spontaneous occurrence of T. domingensis in the substrates of the acid mine drainage passive treatments is an environmental indicator of the efficiency of the system and could be used as a complementary polishing step, given the strong tolerance of this plants to high concentrations of metal/loids.Funding for open access charge: Universidad de Huelva / CBUA M.D. Basallote thanks the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowship granted under application reference IJC2018-035056-I. C.R C´anovas thanks the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowship granted under application reference RYC2019-027949-I

Social Positioning Analysis as a Qualitative Methodology to Study Identity Construction in People Diagnosed With Severe Mental Illnesses

Severe mental illnesses (SMI) in general, and schizophrenia in particular, have been characterized as alterations of the experience of self and identity. When first diagnosed with SMI, the subjective experiences and specific narrative challenges faced by this population are particularly important. Therefore, qualitative approaches which allow to analyze these subjective experiences should be developed. This article presents in detail a specific method, called Social Positioning Analysis, which makes the complexity of narratives and life stories with multiple turning points understandable. To develop this methodological proposal, it has been taken into account the performative aspects of social interaction in which narratives are constructed. The methodology has previously been used in other health contexts and is innovative in the field of mental health. Linguistic criteria, definitions, and multiple examples are included to facilitate its application, as well as some reflections about its potential and possible benefits.Los trastornos mentales graves (TMG) en general, y la esquizofrenia en particular, se han caracterizado como alteraciones de la experiencia del yo y de la identidad. Cuando se diagnostica por primera vez con TMG, las experiencias subjetivas y los desafíos narrativos específicos que enfrenta esta población son particularmente importantes. Por tanto, conviene desarrollar enfoques cualitativos que permitan analizar estas experiencias subjetivas. Este artículo presenta en detalle un método específico, denominado Social Positioning Analysis, que permite comprender la complejidad de las narrativas e historias de vida con múltiples puntos de inflexión. Para desarrollar esta propuesta metodológica se ha tenido en cuenta los aspectos performativos de la interacción social en los que se construyen dichas narrativas. La metodología ha sido utilizada previamente en otros contextos de salud y es innovadora en el campo de la salud mental. Se incluyen criterios lingüísticos, definiciones y múltiples ejemplos para facilitar su aplicación, así como algunas reflexiones sobre sus potenciales y posibles beneficios.Gobierno de España, Ministerio de Ciencia e Innovación PSI2016–80112–

Programa de gestión ambiental para la unidad empresarial de base “Dietéticos”, de la empresa de productos lácteos Bayamo (Original)

An environmental management system gives some guidelines to ensure that an organization or company carries out all its activities in a way that is friendly to the environment. The dairy industry, due to its diversity of processes and products, generates a large amount of solid, liquid and gaseous waste, which can be seenincreased by improving productivity, quality and sanitation of them. The Dairy Products Company of Bayamo considers the development of the environmental management system to be appropriate, taking as reference the ISO 14001, since it is intended to carry out an appropriate handling of materials premiums and inputs of the organization. The Environmental Management was analyzed under the context of the impact that the food industry has on the environment with the aim of diagnosing the main environmental problems in the UEB '' Dieticians '', of the Dairy Products Company of Bayamo. The intention of this research was to propose an Environmental Management program based on what is established in three of the requirements of the NC 14001: 2004; in its sections: 4.2: Environmental policy; 4.3.1: Environmental aspects; 4.3.3: Objectives, goals and programs. It was carried outwithin the months of January 2018 and October 2018. In obtaining the information, theoretical and empirical methods were used, highlighting the survey and two main techniques: scientific observation (direct and indirect), documentary analyzes as well as the semi-standardized interview.Un sistema de gestión ambientalda algunas pautas para lograr que unaorganización o empresa realice todas sus actividades de formaamigable con el medio ambiente.La industria láctea por su diversidad de procesos y productos genera una gran cantidad de residuos sólidos, líquidos y gaseosos los cuales se ven incrementados al mejorar la productividad, calidad y sanidad de los mismos.La Empresa Productos Lácteos Bayamo ha considerado oportuno el desarrollo del sistema de gestión ambiental, tomando como referencia la norma ISO 14001, ya que se pretende llevar a cabo un manejo adecuado de las materias primas e insumos de la organización.La Gestión Ambiental se analizó bajo el contexto del impacto que tiene la industria alimentaria sobre el medio ambiente con el objetivo de diagnosticar los principales problemas ambientales en la UEB ´´Dietéticos´´, de la Empresa Productos Lácteos Bayamo. &nbsp;La intención de esta investigación fue proponer un programa de Gestión Ambiental basado fundamentalmente, en lo establecido en tres de los requisitos de la NC 14001:2004; en sus apartados: 4.2: Política ambiental; 4.3.1: Aspectos ambientales; 4.3.3: Objetivos, metas y programas. Se realizó entre los meses de enero de 2018 a octubre de 2018. En la obtención de la información se emplearon métodos del nivel teórico y empírico, sobresaliendo la encuesta y dos técnicas fundamentales: la observación científica (directa e indirecta), los análisis documentales así como la entrevista semiestandarizada

Soil biodegradation of a benzoxazinone analog proposed as a natural products-based herbicide

Aims Benzoxazinones with the 4-hydroxy-(2H)-1,4- benzoxazin-3(4H)-one skeleton have been proposed as potentially successful models for the development of novel design leads. D-DIBOA has proven to be the most promising base structure in the search for novel herbicide models based on the benzoxazinone skeleton. The biodegradation dynamics of D-DIBOA in soil are therefore relevant and are the subject of this study. Methods A previously optimized methodology for the assessment of biodegradation has been applied for the first time to a synthetic benzoxazinone. Results Biodegradability is a characteristic of natural benzoxazinones and a safety requirement for the development of herbicidal chemicals. The biodegradation phenomenon and its consequences for the development of new herbicide models are discussed. The half-life determined for D-DIBOA was much higher than those previously reported for the natural products DIBOA, DIMBOA and their benzoxazolinone derivatives. Conclusions This finding, together with its previously described potent phytotoxicity, suggests that D-DIBOA is a useful candidate for novel herbicide model development. The lactam D-HBOA, which is slightly less phytotoxic than its precursor, was discovered to be the first and principal metabolite resulting from D-DIBOA degradation

In vitro and in vivo studies of the trypanocidal activity of four terpenoid derivatives against Trypanosoma cruzi.

Four terpenoid derivatives were examined for their activity against Trypanosoma cruzi. Our results show that two compounds were very active in vitro against both extra- and intracellular forms. These compounds, non-toxic for the host cells, are more effective than the reference drug benznidazole. The capacity to infect cells was negatively affected and the number of amastigotes and trypomastigotes was reduced. A wide range of ultrastructural alterations was found in the epimastigote forms treated with these compounds. Some metabolic changes occurred presumably at the level of succinate and acetate production, perhaps caused by the disturbance of the enzymes involved in sugar metabolism inside the mitochondria. In vivo results were consistent with those observed in vitro. The parasitic load was significantly lower than in the control assay with benznidazole. The effects of these products showed the reduction of the anti-T. cruzi antibodies level during the chronic stage

Metal(loid) release from sulfide-rich wastes to the environment: The case of the Iberian Pyrite Belt (SW Spain)

Sulfide-mining wastes may lead to severe environmental and human health risks, especially challenging in abandoned mines without environmental regulation. This work is aimed at discussing the environmental problems associated with this type of wastes, the risks posed by metal(loid) exposure to living organisms, as well as the measures available to mitigate such risks, taking the case of the Iberian Pyrite Belt (SW Iberian Peninsula), as an example, worldwide. The release of metal(loid)s from these wastes upon weathering is strongly controlled by mineral assemblage, processing technique, grain size distribution, and occurrence of highly reactive secondary minerals. Exposure to these wastes may pose a severe risk for humans and animals, and thus, remediation measures must be adopted in abandoned mines. Among these measures, recovery of valuable metals from sulfide wastes could be a promising environmentally friendly solution; however, grade and mineralogical siting of valuable metals, as well as selective recovery methods, must be site-by-site investigated.This work was supported by the Spanish Ministry of Economy and Competitiveness through the research projects SCYRE (CGL2016-78783- C2-1-R) and CAPOTE (CGL2017-86050-R). C.R Ca ́novas and M.D. Basallote thank the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowships granted under application references RYC2019- 027949-I and IJC2018-035056-I, respectively. F. Macı ́as was funded by the R&D FEDER Andalucı ́a 2014e2020 call through the project RENOVAME (FEDER; UHU-1255729). The authors would like to thank to the Guest Editor Dr. Georgios Bartzas and two anonymous reviewers for their helpful comments that notably improved the quality of the original manuscript.Funding for open access charge: Universidad de Huelva / CBU

Thallium in environmental compartments affected by acid mine drainage (AMD) from the Iberian Pyrite Belt (IPB): From rocks to the ocean

This works investigates the origin, behavior and fate of Tl in acid mine drainage (AMD) affected areas at catchment scale, following the path from rocks to the ocean. To address this issue, comprehensive data set of Tl in rocks, waters, secondary minerals, plants and other environmental compartments is presented, using the Iberian Pyrite Belt (SW Spain) as representative example. The content of Tl in host rocks (mean of 0.51 mg/kg) exhibits moderate positive correlations with elements such as K and Rb, whereas no correlations were observed in sulfides (27 mg/kg) between Tl, Fe and other metal/loids commonly found in these minerals, such as As, Pb, Cd, Cu or Zn. During sulfide oxidation processes, Tl is mobilized from sulfides, as evidenced by the depletion of Tl in gossans (1.8 mg/kg), and host rock minerals, leading to a Tl enrichment in AMD leachates (mean of 242 μg/L), with concentrations of up to 8.3 mg/L, several orders of magnitude higher than those reported in natural waters. The precipitation of secondary minerals, with large surface areas, may be a sink for Tl, especially in jarosite minerals (8.4 mg/kg). Thallium can be also removed during the treatment of AMD in alkaline passive treatment systems due mainly to sorption processes onto Fe and Al secondary minerals (i.e., schwertmannite and basaluminite, respectively). Mean Tl contents of 13 mg/kg have been observed in wastes dumped in abandoned mines of the IPB, mainly spoil heaps, slags, roasted pyrite, heap leaching wastes and tailings. However, there is no clear relationship between Tl content and the type of mining wastes. These wastes can suffer weathering, leading to an enrichment of Tl in soils. Previous studies reported that <25% of total Tl is easily extractable, being mainly adsorbed to crystalline Fe oxides in acidic soils and Al oxides in neutral-alkaline soils. Despite this, Tl may be translocated by plants. The translocation of Tl in plants of the IPB has not been properly addressed, however previous studies in other areas showed a low phytoavailability of Tl compared to Cd and Zn, although Tl translocation appears to be strongly controlled by plant species or by differences in Tl speciation. The weathering of rocks, mine wastes and soils may lead to the release of notable amounts of both dissolved and particulate Tl to the hydrosphere. In acidic conditions, Tl seems to be mainly transported by the dissolved phase in AMD-affected streams and rivers, with <15% being transported by the particulate matter. This latter Tl transport may be associated to its incorporation into diatoms and Fe minerals such as jarosite after replacement of Tl+ by H+ in their structure. Subsequent release by desorption processes from jarosite and diatoms in acidic conditions can occur. This process has also been observed in estuaries affected by AMD, thus, Tl transported by jarosite minerals in the particulate matter and diatoms are released back to the estuarine waters across the salinity gradient due to the increasing proportion of unreactive TlCl0 and K+ ions, which compete for adsorption sites in jarosite with Tl+. Thus, enhanced transport of Tl to the oceans is observed in AMD-affected systems.This work was supported by the Spanish Ministry of Economy and Competitiveness under the research project TRAMPA (MINECO; PID2020-119196RB-C21) and the Andalusian Regional Government under the AIHODIEL project (PYC20 RE 032 UHU) within the FEDER program. C.R Canovas thanks the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowship granted under application reference RYC2019-027949-I. M.D. Basallote thanks the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowship granted under application reference IJC2018-035056-I. Funding for open access charge: Universidad de Huelva /CBU