Abstract Objective: The aim of this study was to estimate whether the consumption of anticoagulants was associated with a difference in the frequency of thrombosis of any site, major bleeding and mortality, in adults with both diseases. Method: A retrospective cohort study was carried out in four high complexity centers. Patients older than 18 years with CKD on hemodialysis and non-valvular AF, with an indication for anticoagulation (CHA2DS2VASc ≥ 2), were included. The primary outcome was the occurrence of: major bleeding, thrombotic event (cerebrovascular accident, acute myocardial infarction or venous thromboembolic disease) or death. Adjustment for confounding variables was performed using logistic regression. Results: From 158 patients included, 61% (n = 97) received an anticoagulant. The main outcome was found in 84% of those who received anticoagulation and 70% of those who did not (OR: 2.12, 95%CI: 0.98-4.57; after the adjusted analysis OR: 2.13, 95%CI: 1.04-4.36). Separate outcomes were bleeding in 52% vs. 34% (OR: 2.03; 95%CI: 1.05-3.93), thrombosis in 35% vs. 34% (OR: 1.03; 95%CI: 0.52-2-01) and death in 46% vs. 41% (OR: 1.25; 95%CI: 0.65-2.38). Conclusions: The results of this study suggest an increased risk of bleeding in patients with AF and CKD on hemodialysis receiving anticoagulation, without a decrease in the risk of thrombotic events or all-cause mortality.

Resumen Objetivo: El objetivo de este estudio fue estimar si el uso de anticoagulantes se asociaba con una diferencia en la frecuencia de trombosis de cualquier sitio, hemorragia mayor y mortalidad en adultos con coexistencia de ambas patologías. Método: Se realizó un estudio de cohorte retrospectivo en cuatro centros de alta complejidad. Se incluyeron mayores de 18 años con ERC en hemodiálisis y FA no valvular, con indicación de anticoagulación (CHA2DS2VASc ≥ 2). El desenlace primario fue la ocurrencia de sangrado mayor, evento trombótico (accidente vascular cerebral, infarto agudo al miocardio o enfermedad tromboembólica venosa) o muerte. Se realizó ajuste por variables de confusión por regresión logística. Resultados: De los 158 pacientes incluidos, el 61% (n = 97) recibieron anticoagulante. El desenlace principal se encontró en el 84% de quienes recibieron anticoagulación y en el 70% de quienes no la recibieron (OR: 2.12, IC95%: 0.98-4.57; luego del ajuste OR: 2.13, IC95%: 1.04-4.36). De los desenlaces mayores se presentaron sangrado en el 52% vs. el 34% (OR: 2.03; IC95%: 1.05-3.93), trombosis en el 35% vs. el 34% (OR: 1.03; IC95%: 0.52-2.01) y muerte en el 46% vs. el 41% (OR: 1.25; IC95%: 0.65-2.38). Conclusiones: Los resultados de este estudio sugieren un incremento en el riesgo de sangrado en los pacientes con FA y ERC en hemodiálisis que reciben anticoagulación, sin disminución del riesgo de eventos trombóticos ni de muerte.

Abstract Objective: Analyze sex hormone's influence during Chagas disease. Methods: Male and female BALB/c mice were divided into six groups, four experimental (sham, orchiectomized, orchiectomized and supplemented with estradiol, orchiectomized supplemented with testosterone, oophorectomized, oophorectomized and supplemented with estradiol, and oophorectomized and supplemented with testosterone), and two control (healthy and intraperitoneally with T. cruzi strain NINOA infected). Clinical data were recorded daily, parasitemia was evaluated using a Neubauer chamber during the infection, and heart histopathological analysis was performed using the paraffin embedding technique. To analyze parasitemia curves and the area under the parametric curves, two-way ANOVA test was performed to correlate groups' data. P-values < 0.05 were considered statistically significant. Results: Higher mortality rates, cardiomegaly, hepatomegaly, ascites, edema, higher parasitemia levels, more amastigote nests, and more severe inflammatory infiltrate were found in higher testosterone concentration mice, whereas in higher estradiol concentration groups, paresia, prostration, edema, and necrosis were found. Conclusions: Our results showed that testosterone increased infection severity, whereas estradiol had the opposite effect. This research improves the understanding of sex hormones´ infuence upon this infection to contribute with the handling of Chagas´ disease.

Resumen Objetivo: Analizar la influencia de las hormonas durante la enfermedad de Chagas. Métodos: Se separaron grupos de ratones macho y hembras BALB/c, todos infectados con T. cruzi (cepa NINOA), 4 grupos experimentales de machos (Sham, orquidectamizados, orquidectimezados y suplementados con estradiol, orquidectamizaos y suplementados con testosterona). 4 grupos experimentales de hembras (oforectomizadas, oforectomizadas y suplementadas con estradiol, oforectomizadas y suplementadas con testosterona y sham), and y dos grupos control para cada sexo (sin infección e infectados intraperitonealmente con T. cruzi (cepa NINOA). Los datos clínicos fueron registrados diariamente, la parasitemia fue evaluada durante toda la infección utilizando una cámara de Neubauer y el análisis histopatológico del corazón fue realizada con la técnica de inclusión en parafina. Para el análisis de las curvas de parasitemia y el área bajo la curva, se realizó una prueba de ANOVA de dos vías, p < 0.05 fueron considerados estadísticamente diferentes. Resultados: Las mayores tasas de mortalidad, cardiomegalia, hepatomegalia y mayor infiltrado inflamatorio, se encontró en los ratones con una mayor concentración de testosterona. En contraste los ratones con mayor concentración de estradiol presentaron paresia, postración edema y necrosis. Conclusiones: Nuestros resultados ponen en manifiesto que la testosterona incrementa la severidad del curso de la enfermedad de Chagas, mientras que el estradiol tuvo el efecto opuesto. Este trabajo mejora el entendimiento del rol que juegan las hormonas sexuales en esta infección para contribuir en un mejor manejo de la enfermedad de Chagas.

ABSTRACT • Azadirachta indica A. Juss (Neem) is a tree native to India that, due to its multiple properties, is currently widely distributed throughout the world, mainly in tropical and semi-arid areas, being able to withstand adverse conditions such as high temperatures and soils. arid, infertile, stony or acid. Insect repellents and insecticides, fungicides and fertilizers of extraordinary value for integrated or organic agriculture are made from this plant. The objective of this research is the determination of quality parameters of the physical-chemical variables of the oil from the seeds of Azadirachta indica A. Juss (neem). The oil was extracted, by artisanal cold pressing, from the seeds of fruits collected from specimens cultivated in the San Antonio del Sur municipality of the Guantánamo province. The quality parameters were determined: density, acidity index, pH, refractive, iodine and saponification indices. The values of the oil quality parameters of the neem seeds were shown to be similar to the results of other researchers and to be within the ranges required by the Codex. Of all the parameters, the only one that is above the required values is the acidity index. The Neem oil from trees located in Guantánamo could be an alternative to replace imported vegetable oils for industrial use, although with previous refining processes

RESUMEN • Azadirachta indica A. Juss (Neem) es un árbol originario de la India que, por sus múltiples propiedades, se encuentra en la actualidad distribuido ampliamente en el mundo, principalmente en zonas tropicales y semiáridas, pudiendo soportar condiciones adversas tales como: altas temperaturas y suelos áridos, no fértiles, pedregosos o ácidos. A partir de esta planta se elaboran repelentes de insectos e insecticidas, fungicidas y fertilizantes de extraordinario valor para la agricultura integral o biológica. El objetivo de esta investigación es la determinación de parámetros de calidad de las variables físico-químicas del aceite de las semillas de Azadirachta indica A. Juss (Neem). El aceite se extrajo, mediante prensado al frío artesanal, de las semillas de frutos recolectados de especímenes cultivados en el municipio San Antonio del Sur de la provincia de Guantánamo. Se determinaron los parámetros de calidad: densidad, índice de acidez, pH, índices de refracción, de yodo y de saponificación. Los valores de los parámetros de calidad del aceite de las semillas de Neem mostraron ser similares a los resultados de otros investigadores y que se encuentran dentro los rangos exigidos por el Códex. De todos los parámetros el único que está por encima de los valores exigidos es el índice de acidez. El aceite de neem de árboles localizados en Guantánamo podría constituir una alternativa en la sustitución de aceites vegetales importados de uso industrial, aunque con previos procesos de refinación.

ABSTRACT The application of leaf area index (LAI) in coffee crop management depends on the availability of methodologies for proper estimation. The objective of this study was to develop a methodology for the visual assessment of LAI in coffee fields and to establish a protocol for training, evaluation, and feedback for evaluators. Four rounds of LAI measurements were conducted using visual estimates, two instruments (LAI 2200-C and AccuPAR LP-80), and defoliation of coffee hedgerows in Poás, Costa Rica. In each round, five workers visually estimated the LAI values on two occasions separated by 15 days, and feedback reinforcement was provided to each worker at the end of each round. Visual assessments showed high repeatability and reproducibility and the estimates were adjusted to the linear regression model in most cases. Evaluators improved their capacity to visually assess the LAI throughout the rounds, as the value of R2increased consistently for most workers, with values as high as 0.87. Instrumentation evaluation of LAI produced R2values of 0.5-0.6, with significant underestimation bias. The performance of the different methods is discussed in the context of widely spaced hedgerows. The proposed visual methodology constitutes a statistically sound, rapid, simple, and reliable method for determining the LAI of coffee fields to aid in decision-making for crop management.

RESUMO A aplicação do índice de área foliar (IAF) na gestão da cultura do cafeeiro depende da disponibilidade de metodologias para sua estimativa correta. É proposta aqui uma metodologia para a avaliação visual do IAF em plantas de café, por tanto se estabelece um protocolo para o treinamento dos avaliadores. Foram feitas quatro rodadas de medições do IAF utilizando estimativas visuais, dois instrumentos (LAI 2200-C e AccuPAR LP-80), e desfolhações de sebes de café na Costa Rica. A cada rodada, cinco trabalhadores estimaram visualmente os valores do IAF em duas ocasiões e separados por 15 dias. Ao final de cada rodada, foi dada uma retroalimentação a cada trabalhador. A avaliação visual mostrou alta repetibilidade e reprodutibilidade, e as estimativas foram ajustadas para o modelo de regressão linear na maioria dos casos. Os avaliadores melhoraram sua capacidade de avaliar visualmente o IAF ao longo das rodadas, e o valor de R2 aumentou consistentemente para a maioria dos trabalhadores, com valores tão altos quanto 0,87. A avaliação do IAF por instrumentos produziu valores de R2 de 0,5-0,6, com significativa tendência de subestimação, e não se ajustou ao modelo de regressão linear. O desempenho dos diferentes métodos é discutido no contexto de coberturas com amplo espaço. A metodologia visual proposta constitui uma determinação sólida, rápida, simples e confiável do IAF na lavoura do café e considera-se uma ajuda na tomada de decisões para a gestão da safra.

Abstract Background: Medial arterial calcification (MAC) of the foot is a predictor of cardiovascular morbidity and mortality in diabetics. The MAC score is a tool to describe with plain radiographs the burden of inframalleolar arterial calcification. Objective: To determine the degree of association between MAC and the risk of major amputation. Methods: Retrospective longitudinal cohort study analyzing radiographs of extremities with diabetic foot from March 1, 2021 to July 31, 2022. They were classified according to their MAC score and interventions performed at 6 months were recorded; chi-square test and relative risk test were performed to determine significant association between severe MAC and major amputation. Results: Out of 102 extremities studied, 37 patients (35.9%) had severe MAC; 28 suffered major amputation, with a significant risk estimation (RR: 3.28, CI: 95% 1.985-5.428). Conclusion: Severe MAC in patients with diabetic foot increases 3.2 times the risk of a major amputation during the 6 months following the appearance of an ulcer.

Resumen Antecedentes: La calcificación arterial de la capa media en el pie (CAMP) es un factor predictivo de morbilidad y mortalidad cardiovascular en diabéticos. La puntuación de CAMP es una herramienta para describir con radiografías simples la carga de calcificación arterial infra maleolar. Objetivo: Determinar el grado de asociación entre CAMP con el riesgo de amputación mayor. Métodos: Estudio longitudinal retrospectivo de cohortes analizando radiografías de extremidades con pie diabético del 1 marzo de 2021 al 31 julio de 2022. Se clasificaron según su puntuación CAMP y se registraron las intervenciones realizadas a 6 meses; se realizó prueba de chi cuadrada y riesgo relativo para determinar asociación significativa entre CAMP grave y amputación mayor. Resultados: De 102 extremidades estudiadas, se encontró CAMP grave en 37 pacientes (35.9%); 28 sufrieron amputación mayor, con una estimación de riesgo significativa (RR: 3.28, IC: 95% 1.985-5.428). Conclusión: CAMP grave en paciente con pie diabético aumenta 3.2 veces el riesgo de una amputación mayor durante los 6 meses posteriores a la aparición de una úlcera.

Abstract Background: ST-elevation myocardial infarction (STEMI) systems of care have reduced inter-hospital transfer times and facilitated timely reperfusion goals. Helicopters may be an option when land transportation is not feasible; however, the safety of air transport in patients with acute coronary syndrome (ACS) is a factor to consider. Objetives: The aim of this study was to evaluate the safety of helicopter transport for patients with ACS. Methods: Prospective, observational, and descriptive study including patients diagnosed with ACS within the STEMI network of a metropolitan city transferred by helicopter to a large cardiovascular center to undergo percutaneous coronary intervention. The primary outcome of the study was the incidence of air-travel-related complications defined as IV dislodgement, hypoxia, arrhythmia, angina, anxiety, bleeding, and hypothermia. Secondary outcomes included the individual components of the primary outcome. Results: A total of 106 patients were included in the study; the mean age was 54 years and 84.9% were male. The most frequent diagnosis was STEMI after successful fibrinolysis (51.8%), followed by STEMI with failed fibrinolysis (23.7%) and non-reperfused STEMI (9.4%). Five patients (4.7%) developed at least one complication: IV dislodgement (1.8%) and hypoxemia (1.8%) in two patients and an episode of angina during flight (0.9%). A flight altitude of > 10,000 ft was not associated with complications. Conclusions: The results of this study suggest that helicopter transportation is safe in patients undergoing acute coronary syndrome, despite the altitude of a metropolitan area.

Resumen Antecedentes: Los sistemas de atención de IAMCEST han reducido los tiempos de transferencia interhospitalaria y han facilitado las metas de reperfusión oportuna. Los helicópteros pueden ser una opción cuando el transporte terrestre no es factible; sin embargo, la seguridad del transporte aéreo en pacientes con síndrome coronario agudo (SICA) es un factor a considerar. Objetivos: Evaluar la seguridad del transporte en helicóptero para pacientes con SICA. Métodos: Estudio prospectivo, observacional, descriptivo. Se incluyeron pacientes con diagnóstico de SICA dentro de la red IAMCEST en metrópolis extensa, trasladados en helicóptero a un centro cardiovascular. El resultado primario del estudio fue la incidencia de complicaciones relacionadas con los viajes aéreos definidas cómo desalojo de catéter intravenoso, hipoxia, arritmia, angina, ansiedad, sangrado e hipotermia. Resultados: Total de 106 pacientes; la edad media fue de 54 años y 84,9% eran hombres. La altitud media de vuelo fue de 10,100 pies y la distancia media de vuelo fue de 50,0 km. El diagnóstico más frecuente fue IAMCEST tras fibrinolisis exitosa (51,8%), seguido de IAMCEST con fibrinolisis fallida (23,7%). Cinco pacientes (4,7%) desarrollaron una complicación: desalojo IV (1,8%) e hipoxemia (1,8%) en dos pacientes y un episodio de angina durante el vuelo (0,9%). Una altitud de vuelo mayor de 10,000 pies no se asoció a complicaciones. Conclusiones: Los resultados de este estudio sugieren que el transporte en helicóptero es seguro en pacientes con SICA, incluso en altitudes > 10,000 pies.

ABSTRACT Background: Osteoarthritis is a frequent rheumatic disease. Some single-nucleotide polymorphisms of the gene associated with fat mass and obesity are associated with increased body mass index and knee osteoarthritis. Objective: The objective of this study was to analyze the association of single nucleotide polymorphism rs1477196 of the fat mass and obesity gene with primary knee osteoarthritis. Methods: This observational and cross-sectional study included 347 Mexican participants. We performed the genotypification analysis with TaqMan® probe C_2031262_10 for rs1477196 (Thermo Fisher Scientific). Multivariate analysis included covariables such as age, type 2 diabetes, obesity, and postmenopause. Results: Type 2 diabetes, obesity, and postmenopause were associated with primary knee osteoarthritis in female participants. We did not find an association between rs1477196 and obesity. In the codominant and dominant genetic models, rs1477196 was significantly associated with primary knee osteoarthritis only in the female group, including in the model adjusted by other covariables (odds ratio = 2.517; 1.035-6.123; p = 0.042 and odds ratio = 2.387; 1.054-5.407; p = 0.037, respectively). The interaction between rs1477196 and obesity was significantly associated with primary knee osteoarthritis in female participants (p = 0.039 and p = 0.043). Conclusions: Our findings suggest that the rs1477196 variant of the fat and obesity mass gene may be associated with the risk of primary knee osteoarthritis in women.

Abstract This work aimed to show which treatments showed efficacy against coronavirus disease 2019 (COVID-19); therefore, the results of 37 clinical trials started in 2020 and completed in 2021 are reviewed and discussed here. These were selected from databases, excluding vaccines, computational studies, in silico, in vitro, and those with hyperimmune sera from recovered patients. We found 34 drugs, one vitamin, and one herbal remedy with pharmacological activity against symptomatic COVID-19. They reduced mortality, disease progression, or recovery time. For each treatment, the identifier and type of trial, the severity of the disease, the sponsor, the country where the trial was conducted, and the trial results are presented. The drugs were classified according to their mechanism of action. Several drugs that reduced mortality also reduced inflammation in the most severe cases. These include some that are not considered anti-inflammatory, such as Aviptadil, pyridostigmine bromide, anakinra, imatinib, baricitinib, and bevacizumab, as well as the combination of ivermectin, aspirin, dexamethasone, and enoxaparin. Nigella sativa seeds with honey have also been reported to have therapeutic activity. On the other hand, tofacitinib, novaferon with ritonavir, and lopinavir were also effective, as well as in combination with antiviral therapies such as danoprevir with ritonavir. The natural products colchicine and Vitamin D3 were only effective in patients with mild-to-moderate COVID-19, as was hydroxychloroquine. Drug repositioning has been the main tool in the search for effective therapies by expanding the pharmacological options available to patients.

Resumen El objetivo del presente trabajo fue conocer qué tratamientos mostraron efectividad contra COVID-19, para lo cual se revisan y discuten los resultados de 37 estudios clínicos iniciados durante 2020 y concluidos en 2021. Estos fueron seleccionados de bases de datos, excluyendo vacunas, estudios computacionales, in silico, in vitro y con sueros hiperinmunes de pacientes recuperados. Se documentaron 34 fármacos, una vitamina y un remedio herbolario, con actividad farmacológica ante COVID-19 sintomático. Estos redujeron la mortalidad, el progreso de la enfermedad, o el tiempo de recuperación. Para cada tratamiento se presenta identificador y tipo de estudio, la gravedad de la enfermedad, patrocinador, país donde se realizó, así como sus resultados. Los fármacos se clasificaron de acuerdo con su mecanismo de acción. Varios fármacos que redujeron la mortalidad también disminuyeron la inflamación en los casos más graves. Esto incluyendo algunos no considerados antiinflamatorios, como el aviptadil, el bromuro de piridostigmina, el anakinra, el imatinib, el baricitinib y el bevacizumab, así como la combinación de ivermectina, aspirina, dexametasona y enoxaparina. También se reportaron con actividad terapéutica las semillas de Nigella sativa con miel. Además, resultaron efectivos el tofacitinib, el novaferón con ritonavir y lopinavir, así como los antivirales en terapias combinadas como el danoprevir con ritonavir. Los productos naturales colchicina y vitamina D3, solo tuvieron actividad en los pacientes en estado leve a moderado de la COVID-19, así como la hidroxicloroquina. El reposicionamiento de fármacos fue la principal herramienta para buscar terapias efectivas ampliando las opciones farmacológicas accesibles a los pacientes.

Abstract The gold standard for bariatric surgery is the laparoscopic gastric bypass, which consists in forming a small gastric pouch and a Roux-en-Y anastomosis. We present the case of a 41-year-old female who underwent a laparoscopic gastric bypass 8 years prior to her admission to the emergency room, where she arrived complaining of severe and colicky epigastric abdominal pain. The abdominal computed tomography showed a jejuno-jejunal intussusception, for which the patient underwent urgent exploratory laparotomy with intussusception reduction. Intestinal intussusception is a possible postoperative complication of a Roux-en-Y gastric bypass.

Resumen El método de referencia en la cirugía bariátrica es el bypass gástrico laparoscópico, que consiste en la creación de una bolsa gástrica pequeña, anastomosada al tracto digestivo mediante una Y de Roux. Presentamos el caso de una mujer de 41 años con el antecedente de un bypass gástrico laparoscópico realizado 8 años antes, quien ingresó al servicio de urgencias refiriendo dolor abdominal grave. La tomografía computarizada abdominal evidenció una intususcepción a nivel de la anastomosis yeyuno-yeyuno, por lo que se realizó una laparotomía exploradora con reducción de la intususcepción. Se debe considerar la intususcepción intestinal como complicación posoperatoria de bypass gástrico.

Resumo A presente pesquisa foi feita para determinar a capacidade micronuclei e citotóxica do antidepressivo venlafaxina em ensaios agudos e subcrônicos in vivo em camundongos. No primeiro estudo, administramos uma vez 5, 50 e 250 mg/kg do medicamento e incluímos um grupo negativo e um grupo tratado com daunorubicina. As observações foram feitas diariamente durante quatro dias. O ensaio subcrônico durou cinco semanas com administração diária de venlafaxina (1, 5, e 10 mg/kg) mais um grupo negativo e um grupo administrado de imipramina. As observações foram feitas a cada semana. No primeiro ensaio, os resultados não mostraram aumento de eritrócitos policromáticos micronucleados (MNPE), exceto com a dose elevada a 72 h. O efeito citotóxico mais forte foi encontrado com 250 mg/kg a 72 h (um efeito citotóxico de 51% em comparação com o nível médio de controle). No ensaio subcrônico não foi encontrado aumento de MNPE; entretanto, com a dose mais alta, um aumento significativo de eritrócitos normocromáticos micronucleados foi observado nas últimas três semanas (média de 51% em relação ao valor médio de controle). Foi observado um efeito citotóxico com as duas altas doses nas últimas duas semanas (uma diminuição média de 52% em relação ao valor médio de controle dos eritrócitos policromáticos). Os resultados sugerem cautela com a venlafaxina.

Abstract The present research was made to determine the micronuclei and cytotoxic capacity of the antidepressant venlafaxine in an in vivo acute and subchronic assays in mouse. In the first study, we administered once 5, 50, and 250 mg/kg of the drug, and included a negative and a daunorubicin treated group. Observations were daily made during four days. The subchronic assay lasted 5 weeks with daily administration of venlafaxine (1, 5, and 10 mg/kg) plus a negative and an imipramine administered groups. Observations were made each week. In the first assay results showed no micronucleated polychromatic erythrocytes (MNPE) increase, except with the high dose at 72 h. The strongest cytotoxic effect was found with 250 mg/kg at 72 h (a 51% cytotoxic effect in comparison with the mean control level). In the subchronic assay no MNPE increase was found; however, with the highest dose a significant increase of micronucleated normochromatic erythrocytes was observed in the last three weeks (a mean of 51% respect to the mean control value). A cytotoxic effect with the two high doses in the last two weeks was observed (a polychromatic erythrocyte mean decrease of 52% respect to the mean control value). Results suggest caution with venlafaxine.

Abstract The aim of this study was to assess the in vitro ovicidal activity of an ethyl acetate extract from Arceuthobium vaginatum (EtOAc-E) and their subfractions (AvR5-AvR14) against Haemonchus contortus using the egg hatching inhibition (EHI) test. The EtOAc-E and subfractions were tested at 0.12-2.00 and at 0.015-2.0 mg/mL, respectively. Distilled water and methanol (2%) were used as negative controls and Thiabendazole (0.10 mg/mL) as a positive control. Treatments with a dependent effect on concentration were subjected to regression analysis to determine the effective concentrations (EC50 and EC90). The major secondary compounds present in the extract and subfractions were identified by high performance liquid chromatography (HPLC). The EtOAc-E and AvR9 exhibited the best ovicidal effect recording 97.5 and 100% of EHI at 0.25 mg/mL, respectively. The EtOAc-E and AvR9 displayed an EC50= 0.12 and 0.08 mg/mL, respectively. The HPLC analysis in the EtOAc-E and bioactive fractions indicated the presence of a polyphenol, glycosylated flavanones, quercetin glucoside, cinnamates, coumarin, cinnamic acid derivative, ferulic acid, coumarate, naringenin, protocatechuic acid and naringin. Results demonstrated that A. vaginatum extract and fraction is able to inhibit the egg hatch process of H. contortus and could be a viable option for the control of small ruminant haemonchosis.

Resumo O objetivo deste estudo foi avaliar a atividade ovicida in vitro de um extrato de acetato de etila de Arceuthobium vaginatum (EtOAc-E) e suas subfrações (AvR5-AvR14) contra Haemonchus contortus, utilizando-se o teste de inibição da eclosão de ovos (EHI). O extrato foi testado em 0.12-2.00 mg/mL, e as subfrações foram testadas em 0.15-2.0 mg/mL. Água destilada e metanol (2%) foram utilizados como controles negativos e Tiabendazol (0.10 mg/mL) como controle positivo. Os tratamentos com efeito concentração dependente foram submetidos à análise de regressão para determinação das concentrações efetivas (CE50 e CE90). Os principais compostos secundários, presentes no extrato e nas subfrações, foram identificados por cromatografia líquida de alta eficiência (HPLC). EtOAc-E e subfração AvR9 exibiram o melhor efeito ovicida, registrando-se 97.5 e 100% do EHI a 0.25 mg/mL, respectivamente. O EtOAc-E e AvR9 apresentaram CE50= 0,12 e 0,08 mg/mL, respectivamente. A análise por HPLC nas frações EtOAc-E e bioativas indicou a presença de um polifenol, flavanonas glicosiladas, glicosídeo de quercetina, cinamatos, cumarina, derivado de ácido cinâmico, ácido ferúlico, cumarato, naringenina, ácido protocatecuico e naringina. Os resultados demonstraram que extrato e frações de A. vaginatum são capazes de inibir o processo de eclosão dos ovos de H. contortus, podendo ser uma opção viável para o controle da hemoncose em pequenos ruminantes.

Summary: The species richness-area relationship is considered one of the general laws in ecology. Through the richness of functional types, the scope of species richness is extended toward approaches to assess the functional redundancy of vegetation in vascular plants. The objective of the research was to develop and evaluate a model of the relationship richness-area and richness-species and functional types. For the richness-area relationship, many empirical models have been proposed in the literature, where the potential and the logarithmic stand out. These models, in addition to a second-order polynomial model, can be used to define the species (S) and functional types (Sg) richness relationship. The authors proposed model is based on the kinetics of order n, where the logarithmic and potential models are particular cases. To analyze the statistical adjustments of the considered models, a database of the related species richness and functional types richness was used in relation to the sampling area (A). The results of the application of non-linear regressions show that the kinetic model of order n has the best statistical adjustment, although the potential and logarithmic models are considered viable.

Resumen: La relación riqueza de especies - área es considerada una de leyes generales en ecología. A través de la riqueza de tipos funcionales se amplía el alcance de la riqueza de especies hacia enfoques de evaluación de la redundancia funcional de la vegetación en plantas vasculares. El objetivo de la investigación fue desarrollar y evaluar de un modelo de la relación riqueza-área y riqueza-especies y tipos funcionales. Para la relación riqueza-área en la literatura abundan los modelos empíricos, donde sobresalen el potencial y el logarítmico. Estos modelos, además de un modelo polinómico de segundo orden, pueden ser utilizados para definir la relación riqueza de especies (S) y de tipos funcionales (Sg). Un modelo propuesto por los autores se basa en la cinética de orden n, en el cual el modelo logarítmico y el potencial son casos particulares. En el análisis de los ajustes estadísticos de los modelos considerados, se utilizó una base de datos de la relación riqueza de especies y de tipos funcionales con relación al área de muestreo (A). Los resultados de la aplicación de regresiones no lineales muestran que el modelo de cinética de orden n resultó ser el modelo con mejor ajuste experimental, aunque los modelos potencial y logarítmico se consideran viables.

RESUMEN El presente trabajo tiene la finalidad de dar a conocer el desarrollo de un prototipo de sensor para la medición de mercurio (Hg2+) en solución acuosa sobre una plataforma electroquímica basada en electrodos serigrafiados de nanotubos de carbonos (CNT-SPE) en conjunto con nanopartículas de oro (NPs-Au) realizadas a través de síntesis verde, utilizando extracto acuoso de Sargassum spp. Para esto, se realizó la caracterización de las NPs-Au por espectroscopía ultravioleta-visible (UV-Vis), infrarrojo (TF-IR), difracción de rayos X (DRX) y microscopía electrónica de barrido (SEM); obteniendo nanopartículas entre 80-100 nm las cuales poseen un recubrimiento orgánico que les confiere una sinergia al momento de ser conjugadas con CNT-SPE oxidadas/activadas. Posteriormente, las NPs-Au se utilizaron para modificar el CNT-SPE a través del método drop-casting y así ensamblar un novedoso sensor electroquímico para la medición de Hg2+, cuya validación y habilidad para medir fue demostrada utilizando voltametría diferencial de pulso (DPV). Se obtuvieron límites de detección de 2.38 𝜇M y cuantificación de 3 𝜇M. Los resultados demuestran que la plataforma desarrollada es una alternativa, rápida, eficiente y portátil para la medición de Hg2+.

ABSTRACT The present manuscript’s objective is to develop a sensor prototype for measuring mercury (Hg2+) in an aqueous solution. An electrochemical platform based on screen-printed carbon nanotube electrodes (CNT-SPE) and gold nanoparticles (NPs-Au) synthesized using a green synthesis method with an aqueous extract of Sargassum spp. For this, the characterization of the NPs-Au was carried out by ultraviolet-visible (UV-Vis), infrared (TF-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) spectroscopy. The nanoparticles have sizes between 80-100 nm and an organic coating that allows them a synergy when conjugated with oxidized/activated CNT-SPE. Subsequently, the NPs-Au were used to modify the CNT-SPE through the drop-casting method and thus assemble a novel electrochemical sensor for the measurement of Hg2+, whose validation and ability to measure was demonstrated using differential pulse voltammetry (DPV). Detection limits of 2.38 𝜇M and quantification of 3 𝜇M were obtained. The results show that the developed platform is a fast, efficient and portable alternative for the measurement of Hg2+.

RESUMEN En el comienzo de la historia del grafeno, el óxido de grafeno representaba únicamente un paso intermedio en la metodología para la obtención de láminas de grafeno. Sin embargo, resultados posteriores en la investigación de este material mostraron que el óxido de grafeno exhibe una estructura con defectos y grupos funcionales que le confieren propiedades únicas. Dada la versatilidad de su superficie, se han propuesto distintas vías de funcionalización que han resultado en la obtención de gran variedad de materiales híbridos. En este trabajo, presentamos la obtención y caracterización de tres materiales funcionalizados basados en láminas de óxido de grafeno decoradas con nanopartículas de plata, dióxido de titanio e hidroxiapatita. Estas nanoestructuras fueron caracterizadas mediante difracción de rayos X, espectroscopía Raman y microscopía electrónica de transmisión. De forma particular se estudió la mejora en las propiedades térmicas del grafeno oxidadonanopartículas de plata mediante análisis termogravimétrico (TGA), la mejora de las señales Raman mediante el mecanismo químico de SERS en el material decorado con dióxido de titanio y se realizó un ensayo de viabilidad celular MTT, en el que se observó que no presentaba citotoxicidad el grafeno oxidado decorado con hidroxiapatita obtenido al usar urea para la precipitación del biocerámico.

ABSTRACT In the early history of graphene, graphene oxide represented only an intermediate step in the methodology for obtaining graphene sheets. However, subsequent results of the investigation of this material showed that graphene oxide exhibits a structure with defects and functional groups that give it unique properties. Given the versatility of its surface, different functionalization routes have been proposed that have resulted in obtaining a wide variety of hybrid materials. In this work, we present the obtaining and characterization of three functionalized materials based on graphene oxide sheets decorated with nanoparticles of silver, titanium dioxide and hydroxyapatite. These nanostructures were characterized by X-ray diffraction, Raman spectroscopy and transmission electron microscopy. In particular, the improvement in the thermal properties of oxidized graphene-silver nanoparticles was studied through thermogravimetric analysis (TGA), the improvement of Raman signals through the chemical mechanism of SERS in the material decorated with titanium dioxide and a MTT cell viability assay, in which it was observed that the oxidized graphene decorated with hydroxyapatite obtained using urea did not present cytotoxicity.