[S,S]-EDDS Ligand as a Soil Solubilizer of Fe, Mn, Zn, and Cu to Improve Plant Nutrition in Deficient Soils

The deficiencies of iron, manganese, zinc, and copper in calcareous soils are a worldwide problem affecting plant growth and fruit quality, usually minimized by the application of recalcitrant synthetic metal chelates. Biodegradable ligand [S,S]- EDDS is an eco-friendly substitute. This study investigates the capacity of [S,S]-EDDS to mobilize micronutrients from agronomic soils and improve plant nutrition. A batch and a plant experiment (Phaseolus vulgaris cv. Black Pole) with three agronomic soils was conducted to monitor the micronutrients solubilized by [S,S]-EDDS, the ligand degradation, and plant uptake. The results demonstrated the high capacity of [S,S]-EDDS to solubilize Fe and other micronutrients related to its chemical behavior and the enhancement of plant nutrition. The best results were shown in sandy-clay soil with low Fe, typically found in the Mediterranean areas. The results support the direct application of the ligand to soils and a possible biotechnological application of the ligandproducer bacteriaAuthors gratefully acknowledge the financial support by Spanish Ministry of Economy and Competitiveness project: RTI2018-096268-B-I00, and the Comunidad de Madrid (Spain) and Structural Funds 2014−2020 (ERDF and ESF) project AGRISOST-CM S2018/BAA-433

Fast determination of a novel iron chelate prototype used as a fertilizer by liquid chromatography coupled to a diode array detector

The environmental risk of the application of synthetic chelates has favored the implementation of new biodegradable ligands to correct Fe-deficient plants. This study developed and validated an analytical method for determination of a new prototype iron chelate-Fe(III)-benzeneacetate, 2-hydroxy-α-[(2-hydroxyethyl)amino]-(BHH/Fe3+) based on liquid chromatography with diode array detection, as a potential sustainable alternative. Chromatographic analysis was performed on a LiChrospher RP-18 in reverse-phase mode, with a mobile phase consisting of a mixture of acetonitrile (solvent A) and sodium borate buffer 0.20 mM at pH = 8 (solvent B) at a flow rate of 1.0 mL/min in isocratic elution mode. This method was fully validated and found to be linear from the limit of quantification (LOQ) to 50 mg/L and precise (standard deviation below 5%). The proposed method was demonstrated to be selective, precise, and robust. The developed methodology indicated that it is suitable for the quantification of iron chelate BHH/Fe3+The authors gratefully acknowledge the financial support by the Spanish Ministry of Economy and Competitiveness Project RTI2018-096268-B-I00, and the Comunidad de Madrid (Spain) and Structural Funds 2014−2020 (ERDF and ESF) project AGRISOST-CM S2018/BAA-433

Plaguicidas organoclorados y organofosforados en aguas y sedimentos del Río San Juan y sus principales sub-cuencas 1992,1993 y 1997

El presente trabajo tiene por objetivo realizar un estudio comparativo sobre los niveles de Plaguicidas organoclorados y organofosforados en aguas y sedimentos en el Río San Juan y el aporte potencial de sus principales sub-cuencas. Este estudio fué realizado en los meses de Julio de 1992, Septiembre de 1993 y Mayo de 1997. De los plaguicidas organoclorados analizados en agua, en el muestreo de 1992, los de mayor incidencia fueron: dieldrín, y lindano en concentraciones máximas de 2.67 ng.L–1 y 0.94 ng.L–1 respectivamente. En el caso de los organofosforados fueron: malatión y terbufos ( 129.2 ng.L–1 y 77.3 ng.L–1 ). En los sedimentos, el plaguicida organoclorado con mayor presencia fue: dieldrín ( 4.51 ng.L–1 ) y de los organofosforados fueron: malatión ( 64,498 ng.L–1 ) y terbufos ( 342 ng.L–1 ). Las concentraciones de plaguicidas organofosforados en agua, del muestreo de 1997 mostraron presencia de fentión y el etil-paratión en concentraciones máximas de 257 ng.L–1 y 126 ng.L–1 respectivamente. Entretanto, en las muestras de sedimentos se detectaron los plaguicidas organoclorados: lindano, pp-DDT, pp-DDE y pp-DDD en concentraciones máximas de 63 pg.g-1; 271.77 pg.g-1; 122.15 pg.g-1; y 124.50 pg.g-1 respectivamente. Son alarmantes las concentraciones de plaguicidas detectadas en el río San Juan y sus principales sub-cuencas, de no tomarse acciones correctivas, las situación futura sería de mayor acumulación en el sedimento causando un impacto negativo en el ecosistema

Adição de OptiLisina® à dieta de juvenis do axolote Ambystoma velasci para o seu crescimento e sobrevivência

The axolotl Ambystoma velasci is an endemic amphibian of Mexico, due to different environmental and anthropogenic pressures the wild populations have decreased, for which it is listed in NOM-059-SEMARNAT-2010 as a species subject to special protection. An important aspect for their well-being, development, and adaptation in captivity is offering a varied diet; however, there are no studies on the nutritional requirements of this genus of salamanders. In captivity, one of the favorite foods of this amphibian is the mudworm Tubifex spp., but live food does not always cover the nutritional requirements, therefore, strategies are sought to improve the quality of the food, one of them is its enrichment, incorporating supplements, such is the case of the OptiLisina® formula, which is an herbal supplement characterized by being a source of lysine, which when added to the diet has a positive influence as a growth promoter. The objective of this study was to evaluate the parameters of growth, food consumption and survival with the addition of OptiLisina® to the diet of A. velasci juveniles under captive conditions. The experimental design consisted of a trial with 120 individuals of 110 days of age distributed in three levels of OptiLisina® (0, 0.5 and 1.0 g/kg) added to the Tubifex spp., with four repetitions each. The growth in weight and height was recorded to calculate the productive parameters and to be analyzed in a Completely Random Design using orthogonal linear and quadratic polynomials to evaluate the effect of the herbal supplement (P<0.05) in the Software, R. The results of the diet did not show linear or quadratic effects on productive parameters (P> 0.05). More studies are needed on the nutritional requirements of this amphibian, in order to carry out better feeding strategies for the species and favor its maintenance in captivity.El ajolote Ambystoma velasci es un anfibio endémico de México, debido a las presiones ambientales y antropogénicas sus poblaciones silvestres han disminuido, por lo cual se encuentra enlistado como especie sujeta a protección especial (NOM-059-SEMARNAT-2010). Un aspecto importante para su bienestar, desarrollo y adaptación en cautiverio es ofrecer una dieta variada; sin embargo, no existen estudios acerca de los requerimientos nutricionales en este género de salamandras. En cautiverio, uno de los alimentos de predilección de este anfibio es el gusano de fango Tubifex spp., aunque no siempre el alimento vivo cubre los requerimientos nutricionales, por ende, se buscan estrategias para mejorar la calidad del alimento, una de ellas es su enriquecimiento, incorporando suplementos, tal es el caso de la fórmula OptiLisina® que es un complemento herbal que se caracteriza por ser fuente de lisina, que adicionado a la dieta influye positivamente como promotor de crecimiento. El objetivo del presente estudio fue evaluar los parámetros de crecimiento, consumo de alimento y supervivencia con la adición de OptiLisina® a la dieta de juveniles de A. velasci en condiciones de cautiverio. El diseño experimental  consistió en un ensayo con 120 individuos de 110 días de edad distribuidos en tres niveles de OptiLisina® (0, 0,5 y 1,0 g/kg) adicionado al Tubifex spp., con cuatro repeticiones cada uno. Se registró el crecimiento en peso y talla para calcular los parámetros productivos y ser analizados en un Diseño Completamente al Azar empleando polinomios lineales y cuadráticos ortogonales para evaluar el efecto del complemento herbal (P<0.05) en el Software, R. Los resultados de la dieta no mostraron efectos lineales ni cuadráticos en los parámetros productivos (P> 0,05). Se necesitan realizar más estudios sobre los requerimientos nutricionales de este anfibio, para así realizar mejores estrategias de alimentación para la especie y favorecer su mantenimiento en cautiverio.O axolote Ambystoma velasci é um anfíbio endêmico do México, devido a diferentes pressões ambientais e antrópicas as populações selvagens diminuíram, pelo que está listado no NOM-059-SEMARNAT-2010 como uma espécie sujeita a proteção especial. Um aspecto importante para seu bem-estar, desenvolvimento e adaptação em cativeiro é oferecer uma dieta variada, porém não existem estudos sobre as exigências nutricionais desse gênero de salamandras. Em cativeiro, um dos alimentos preferidos deste anfíbio é a minhoca Tubifex spp., porém a alimentação viva nem sempre cobre as exigências nutricionais, por isso, buscam-se estratégias para melhorar a qualidade da alimentação, uma delas é o seu enriquecimento, incorporando suplementos, como é o caso da fórmula OptiLisina®, que é um suplemento fitoterápico caracterizado por ser fonte de lisina, que quando adicionado à dieta tem influência positiva como promotor de crescimento. O objetivo deste estudo foi avaliar os parâmetros de crescimento, consumo alimentar e sobrevivência com a adição de OptiLisina® à dieta de juvenis de A. velasci em cativeiro. O delineamento experimental consistiu em um ensaio com 120 indivíduos de 110 dias de idade distribuídos em três níveis de OptiLisina® (0, 0,5 e 1,0 g/kg) adicionado ao Tubifex spp., com quatro repetições cada. O crescimento em peso e altura foi registrado para calcular os parâmetros produtivos e para ser analisado em um Projeto Completamente Aleatório usando polinômios ortogonais lineares e quadráticos para avaliar o efeito do suplemento de ervas (P<0,05) no Software, R. Os resultados de a dieta não apresentou efeitos lineares ou quadráticos nos parâmetros produtivos (P>0,05). Mais estudos são necessários sobre as exigências nutricionais deste anfíbio, a fim de realizar melhores estratégias alimentares para a espécie e favorecer sua manutenção em cativeiro

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Nuevos quelatos de hierro y mezclas de micronutrientes quelados y complejados: caracterización y evaluación para su uso como fertilizantes

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Agrícola. Fecha de lectura: 17-07-201

Zn and Mn o,p-EDDHA chelates for soybean nutrition in hydroponics in high pH conditions

The low solubility of the iron, manganese and zinc oxides in the pH range of calcareous soils contributes, among other factors, to the low availability of these nutrients to plants. The aim of this work was study the efficacy of the application of Fe, Mn, Zn and Cu chelates to correct the deficiencies in soybean in hydroponic solution in the presence of CaCO3. Fe was applied as o,oEDDHA/Fe3+ in all the cases while Mn, Zn and Cu were applied as o,pEDDHA, EDDS, EDTA, HEDTA or DTPA chelates, with the same chelating agent for the three metals in the same treatment and two additional treatments with Mn and Cu chelated by EDTA and Zn chelated by o,pEDDHA or EDDS. Three controls with no Mn, no Zn and no Mn and Zn with the others chelated by EDTA were tested too. Results indicate that the content of Fe in leaf was similar in all the treatments due the same chelated was applied. The treatments that presented the higher levels for Mn and Zn in leaf, especially for Zn, was the one with the application of Mn and Zn as o,pEDDHA. The higher level for Cu was produced in the treatment with EDTA. It seems that the less stable phenolic chelates for Mn and Zn, like o,pEDDHA, are adequate for the nutrition of Mn and Zn in hydroponics due the low competence of this chelating agent with the plant for the metals

Reactivity and effectiveness of traditional and novel ligands for multi-micronutrient fertilization in a calcareous soil

This study compares the effectiveness of multi-micronutrient formulations containing Fe, Mn, and Zn with traditional (EDTA, DTPA, HEEDTA, EDDHAm) or novel chelates (o,p-EDDHA, S,S-EDDS, IDHA) and natural complexing agents (gluconate and lignosulfonate). The stability and reactivity of the formulations were studied on batch experiments with calcareous soil and by speciation modeling. Formulations containing traditional ligands maintained higher Mn but lower Zn concentration in soil solution than the novel ligands. The gluconate and lignosulfonate maintained low concentrations of both Mn and Zn in soil solution. Selected formulations were applied into calcareous soil and their efficacy was evaluated in a pot experiment with soybean. The formulation containing DTPA led to the highest Zn concentration in plants, as well as the formulation containing S,S-EDDS in the short-term, which correlated with its biodegradability. The application of traditional or novel ligands in formulations did not result in sufficient plant Mn concentrations, which was related to the low Mn stability observed for all formulations under moderate oxidation conditions. The results highlight the need to consider the effect of metals and ligands interactions in multi-nutrient fertilization and the potential of S,S-EDDS to be used for Zn fertilization. Furthermore, it is necessary to explore new sources of Mn fertilization for calcareous soils that have greater stability and efficiency, or instead to use foliar fertilization

Thermodynamic Database Update to Model Synthetic Chelating Agents in Soil Systems

Poliaminocarboxylate and polyaminophenolcarboxylate chelating agents, being the most representatives EDTA and o,o-EDDHA, have been profusely studied by our research team during the last 25 years because they are synthetized to be mainly used as micronutrient fertilizers to correct nutritional disorders affecting largely on crop yields placed under Mediterranean conditions. In the last years new chelating agents were designed and synthesized and the most of them were proposed to be included in the current European Directive on Fertilizers. Overall chelating agent properties, including equilibrium in soil by modeling, should be taken in account in order to check the iron chlorosis correction ability. Chemical speciation programs such as MINTEQA2, and most recently VMinteq, are being successfully used as tools to predict the behavior of each novel chelating agent in soil-plant system. Nowadays just one polyaminophenolcarboxylate chelating agent (o,o-EDDHA) is available into a VMinteq-compatible database (Lindsay's database) whereas more than seven of these type of products are authorized by European fertilizers normative to be used as micronutrient fertilizers. Therefore the aim of this work was the database updating to include all chelating agents related to o,o-EDDHA and EDTA whose complete characterization is performed and published elsewhere. Once database is updated, further modelization studies such as equilibrium reactions and adsorption isotherms with solid phase may be readily performed to get fundamental information and understand the reactivity of these recalcitrant polyaminophenolcarboxylates in soils