This paper presents an analytical multiresidue method for the quantification of 7 nitroimidazoles, 19 anthelmintics, 3 amphenicols, and 4 dyes in poultry, pork, beef, horse, shrimp, and fish samples by isotope dilution ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) in a single 6 min run. Samples were prepared using a modified quick, easy, cheap, effective, rugged and safe (QuEChERS)-type extraction with ethyl acetate and Na2SO4-NaCl (2:1), concentration into dimethyl sulfoxide (DMSO), and defatting by liquid-liquid extraction (LLE) with n-hexane. No clean-up using solid-phase extraction (SPE) cartridges or dispersive solid-phase extraction (DSPE) was necessary. The linearity ranges (in μg kg-1) were 0.10-0.60 for chloramphenicol, 0.50-3.0 for dyes, 1.5-9.0 for nitroimidazoles, and 5.0-30.0 for the other drugs. The limits of quantitation (LOQ) were established at the lowest calibration curve levels. Except for chloramphenicol in the horse matrix, analyte recovery and reproducibility were satisfactory (recovery (fREC): 75.0 to 116.6%; coefficient of variation (CV): 1.2 to 29.9%). For the unapproved substances and the substances with a maximum residue level (MRL), respectively, the decision limits (CCα) were 0.14-4.10 and 5.28-1003.60 μg kg-1, while the detection capabilities (CCβ) were 0.13-3.33 and 5.46-11.56 μg kg-1.

Molecular and periodic allotropes based on cyclo[18]carbon, known as archicarbons, were investigated using density functional theory (DFT) in both molecular and periodic models. This study explores the physicochemical characteristics of these exquisite carbon allotropes, including various molecular archicarbons (spiro[18]carbon, bicyclo[8]carbon, 0-tricyclo[8] carbon, 0-bi(cyclo[19]carbon), l-bi(cyclo[19]carbon), and 0-fused[18]carbon) and periodic archicarbons (poly-spiro[8]carbon, poly-0-bi(cyclo[8]carbon), poly-l-bi(cyclo[8]carbon)). Most proposed molecular archicarbons showed higher cohesive energy than cyclo[18]carbon, except for bicyclo[8]carbon, which suggests that those may be experimentally observable. Proposed synthetic routes for both molecular and periodic archicarbons are suggested, highlighting their potential, particularly in semiconductor applications, and paving the way for further exploration of their distinct electronic properties.

In the present work, we developed an experimental class for undergraduate students concerning the linear synthesis of 2-phenylimidazo[1,2-α]pyridine through mechanochemical techniques. This approach aims to conceptualize the green chemistry principles through a safe, robust, atom-economic, energy-efficient, and solvent-free method for preparing these classes of compounds by manual grinding and vortex mixing. The methodology was easily applied in experimental classes for chemistry students and could be easily expanded to other courses such as pharmacy and biotechnology.

It is essential to diversity energy sources for ensuring sustainability. While hydrogen is considered a promising energy storage medium, its potential hinges on the development of efficient photocatalysts for green production. In addressing this challenge, we evaluated the performance of a heterojunction system composed of non-stoichiometric molybdenum oxides (MoO3−x) and cadmium sulfide (CdS) quantum dots (QDs) for water splitting. MoO3−x were synthesized via gamma irradiation of the MoO3 in the presence of formic acid (FA), while CdS-MPA QDs were electrosynthesized. The heterojunction was formed through adsorption. The structural and electronic characterization revealed a progressive transformation from MoO3 to MoO3−x and MoO3−x/CdS-MPA QDs, demonstrating enhanced water-splitting performance. Upon evaluation, the study revealed a charge transfer mechanism, highlighting the significance of relative band positions between MoO3−x and CdS-MPA QDs in promoting eco-friendly hydrogen evolution and methanol processing. Thus, we suggest that the synergism between MoO3−x and CdS-MPA QDs semiconductors makes the heterojunction system a promising solution for photocatalytic production of hydrogen and oxygen.

RESUMO Mundialmente o consumo de morangos é bastante apreciado, tanto na forma in natura ou industrializada. A produção brasileira depende da importação de mudas de morangueiro de países como Espanha, Chile e Argentina, as quais são cultivares melhoradas em climas temperados, e, consequentemente, não se adaptam bem às condições tropicais brasileiras. Assim, programas de melhoramento genético são fundamentais para geração de cultivares mais adaptadas. Objetivou-se avaliar e caracterizar o desempenho de genótipos experimentais de morangueiro. O delineamento experimental adotado foi em blocos cazualizados, com 12 tratamentos e 3 repetições, sendo os tratamentos constituídos de sete genótipos experimentais e cinco cultivares comerciais. Avaliou-se os parâmetros: produção total por planta (g/planta), peso médio de frutos por planta (g/fruto), % de frutos comerciais por planta, e caracterização morfológica. Os genótipos experimentais MFA12-443, MCA94, MDA23, MDA06 e MCA89 apresentaram as maiores produções de frutos por planta, respectivamente de 285 g, 254 g, 298 g, 295 g e 290 g, com destaque para o genótipo MFA12-443, que também apresentou maior peso médio de frutos (20,35 g) e porcentagem de frutos comerciais (81%). apreciado industrializada Espanha Argentina temperados consequentemente brasileiras Assim adaptadas Objetivouse Objetivou cazualizados 1 repetições Avaliouse Avaliou parâmetros g/planta, gplanta g/planta , (g/planta) g/fruto, gfruto g/fruto fruto (g/fruto) morfológica MFA12443, MFA12443 MFA MFA12 443, 443 MFA12-443 MCA94 MCA MDA23 MDA MDA0 MCA8 28 25 29 20,35 2035 20 35 (20,3 81%. 81 81% . (81%) (g/planta (g/fruto MFA1244 MFA1 44 MFA12-44 MCA9 MDA2 2 20,3 203 (20, 8 (81% MFA124 4 MFA12-4 20, (20 (81 MFA12- (2 (8 (

ABSTRACT In the world the consumption of strawberries is very appreciated, both in natura or industrialized form. Brazilian production depends on the importation of strawberry seedlings from countries such as Spain, Chile and Argentina, which are cultivars improved in temperate climates and, consequently, not well adapted to the Brazilian tropical conditions. Thus, genetic breeding programs are essential for the generation of more adapted cultivars. The objective was to evaluate and characterize the performance of experimental strawberry genotypes. The statistical design adopted was in randomized blocks, with 12 treatments and 3 replications, the treatments consisting of seven experimental genotypes and five commercial cultivars. We evaluated the total production per plant (g/plant), average weight of fruits per plant (g/fruit), % of commercial fruits per plant, and morphological characterization. The experimental genotypes MFA443, MCA94, MDA23, MDA06 and MCA89 showed the highest strawberry yields per plant, respectively, 285 g, 254 g, 298 g, 295 g and 290 g, with emphasis on the genotype MFA12-443, which also presented the highest average weight of fruits (20.35 g) and percentage of commercial fruits (81%). appreciated form Spain Argentina consequently conditions Thus blocks 1 replications g/plant, gplant g/plant , (g/plant) g/fruit, gfruit g/fruit fruit (g/fruit) characterization MFA443 MFA MCA94 MCA MDA23 MDA MDA0 MCA8 respectively 28 25 29 MFA12443, MFA12443 MFA12 443, 443 MFA12-443 20.35 2035 20 35 (20.3 81%. 81 81% . (81%) (g/plant (g/fruit MFA44 MCA9 MDA2 2 MFA1244 MFA1 44 MFA12-44 20.3 203 (20. 8 (81% MFA4 MFA124 4 MFA12-4 20. (20 (81 MFA12- (2 (8 (

RESUMEN Objetivo: Determinar las características clínicoecográficas pre y postquirùrgicas de niños intervenidos por criptorquidia. Material y métodos: Estudio descriptivo y longitudinal, los datos recolectados de historias clínicas del Hospital Sabogal, las variables fueron edad del diagnóstico, tiempo de espera de orquidopexia, testículo afectado, ubicación del testículo y volumen testicular. Resultados: Se incluyeron 34 niños menores de 14 años con criptorquidia, la edad del diagnóstico fue 44 meses y de la orquidopexia 49 meses. El tiempo de espera para la orquidopexia fue 4,72 meses, el testículo más afectado fue el derecho (58,82%). Se incluyeron 39 testículos, la ubicación primaria canalicular (71,79 %), la ubicación final escrotal (50,0%), la técnica operatoria fue inguinal (91,18%). El incremento de volumen testicular fue de 0,39 cm3, p = 0,0006, IC 95% (-0,62, -0,17). Conclusiones: La edad de la orquidopexia fue 49 meses y el volumen testicular aumentó en 0,39 cm3 después de la orquidopexia.

ABSTRACT Objective: To determine the preand post-surgical clinical-ultrasound characteristics of children operated on for cryptorchidism. Material and methods: Descriptive and longitudinal study, data collected from medical records of the Hospital Sabogal, the variables were age at diagnosis, waiting time for orchidopexy, affected testicle, location of the testicle and testicular volume. Results: We included 34 children under 14 years with cryptorchidism, the age of diagnosis was 44 months and orchidopexy 49 months. The waiting time for orchidopexy was 4.72 months, the most affected testicle was the right (58.82%). 39 testicles were included, the primary canalith location (71.79 %), the final scrotal location (50.0%), the operative technique was inguinal (91.18%). The increase in testicular volume was 0.39 cm3, p = 0.0006, 95% CI (-0.62, -0.17). Conclusions: The age of orchidopexy was 49 months and testicular volume increased by 0.39 cm3 after orchidopexy.

RESUMO Há grande demanda de novas cultivares adaptadas para a produção em clima nacional, o que cria certa dependência dos produtores de morango nacionais às cultivares importadas. Com isso, o objetivo do trabalho foi avaliar características de qualidade e morfológicas de frutas provenientes de genótipos de morangueiro. Os acessos de morangueiro foram cedidos pelo Banco de Germoplasma da Universidade Federal de Lavras. O experimento foi implantado no setor de Experimentação e de Olericultura da Universidade José do Rosário Vellano (UNIFENAS). O delineamento experimental utilizado foi em blocos casualizados, com 12 tratamentos e 3 repetições, totalizando 36 unidades experimentais. Os 12 tratamentos foram constituídos de sete genótipos e cinco cultivares comerciais posicionadas em 29 slabs, em cultivo protegido. Os genótipos MFA12-443 e MCA12-89 destacaram-se no tamanho de seus frutos (p<0,000), apresentando os maiores valores de comprimento (41,06 mm), largura (32,60 mm) e espessura (27,84 mm), enquanto não se diferenciaram entre si para estes valores. Estes genótipos apresentam melhor aptidão para o mercado in natura, com características de qualidade mais apreciadas pelos consumidores. Todos os genótipos apresentaram níveis maiores que 7ºBrix (p= 0,000) indicados para a comercialização no mercado. Os acessos testados apresentaram qualidade e aptidão para a produção na região do sul de Minas Gerais.

ABSTRACT There is great demand for new cultivars adapted for production in a national climate, which creates a certain dependence of national strawberry growers on imported cultivars. Thus, the objective of this work was to evaluate quality and morphological characteristics of fruits from strawberry genotypes. Strawberry accessions were provided by the Germplasm Bank of the Federal University of Lavras. The experiment was implemented in the Experimentation and Olericulture sector of the José do Rosário Vellano University (UNIFENAS). The experimental design used was in randomized blocks, with 12 treatments and 3 replications, totaling 36 experimental units. The 12 treatments consisted of seven genotypes and five commercial cultivars positioned in 29 slabs, in protected cultivation. The genotypes MFA12-443 and MCA12-89 stood out in terms of fruit size (p<0.000), presenting the highest values for length (41.06 mm), width (32.60 mm) and thickness (27.84 mm), while not differed from each other for these values. These genotypes are better suited for the fresh market, with quality characteristics that are more appreciated by consumers. All genotypes presented higher levels than 7ºBrix (p= 0.000) indicated for commercialization in the market. The tested accessions showed quality and aptitude for production in the southern region of Minas Gerais.

RESUMEN Objetivo: Investigaciones anteriores coinciden en que el enriquecimiento de alimentos es la mejor estrategia a largo plazo en la prevención de la deficiencia de hierro. Nuestro objetivo es evaluar el efecto de una mezcla láctea fortificada con hierro y zinc sobre los niveles de hemoglobina en niños de 2 a 10 años. Material y métodos: Se realizó un ensayo clínico aleatorizado, doble ciego, controlado con en una comunidad ubicada a 2.590 metros sobre el nivel del mar. Se incluyeron niños con niveles normales de hemoglobina o anemia leve. Asignamos a los participantes que recibieran la mezcla láctea fortificada con hierro y zinc o una mezcla láctea no fortificada. El suplemento se administró cinco días a la semana durante 24 semanas. Nuestro resultado principal fue el nivel de hemoglobina corregida tomando en cuenta la altura sobre el nivel del mar y los índices antropométricos se evaluaron como resultado secundario. La magnitud de la diferencia observada entre los grupos se estimó mediante la prueba t de Student. Todos los análisis se realizaron por intención de tratar. Resultados: Se asignaron al azar 67 niños, intervención: n=32 y control: n=35. La edad media fue de 5,8 años; 30 eran mujeres. La hemoglobina al final del seguimiento fue 13,1 gr/dL (0,9) en el grupo experimental mientras que, en el grupo control, fue de 12,1 gr/dL (0,8); p <0,001. Asimismo, se evidenció una diferencia positiva en los indicadores antropométricos en el grupo experimental. Conclusión: La mezcla láctea fortificada con hierro y zinc aumenta los niveles de hemoglobina y los índices antropométricos en niños de 2 a 10 años.

ABSTRACT Objective: Previous research agrees that food fortification is the best long-term strategy for preventing iron deficiency. Our goal is to evaluate the effect of a dairy mixture fortified with iron and zinc on hemoglobin levels in children aged 2 to 10 years. Material and methods: A randomized, double-blind, controlled clinical trial was conducted in a community located 2,590 meters above sea level. Children with normal levels of hemoglobin or mild anemia were included. We assign participants to receive the iron-zinc-fortified dairy mixture or an unfortified dairy mixture. The supplement was administered five days a week for 24 weeks. Our main result was the corrected hemoglobin level taking into account the height above sea level and anthropometric indices were evaluated as a secondary result. The magnitude of the difference observed between the groups was estimated by the Student t-test. All analyzes were done with the intention to treat. Results: 67 children were randomly assigned, intervention: n=32 and control: n=35. The mean age was 5.8 years; 30 were women. Hemoglobin at the end of the follow-up was 13.1 g/dL (0.9) in the experimental group, while, in the control group, it was 12.1 g/dL (0.8); p <0.001. Likewise, a positive difference was evidenced in the anthropometric indicators in the experimental group. Conclusion: Dairy mixture fortified with iron and zinc increases hemoglobin levels and anthropometric indices in children from 2 to 10 years old.

Abstract: Introduction: Intrathyroidal ectopic thymus (IET) is a rare benign condition caused by the aberrant thymic migra tion during embryogenesis. It is usually incidentally diagnosed as a thyroid nodule. Objective: To report the intrathyroidal location of ectopic thymic tissue and to describe the ultrasound findings in children. Patients and Method: Retrospective descriptive review of the medical charts and thyroid ultrasound studies of children with nodular images in the thyroid gland, in a third level national pediatric hospital, from January 2010 to August 2017. Solid hypoecogenic intrathyroid lesions with multiple linear tracts or hyperechogenic points that did not change their characteristics during fo llow-up were considered intrathyroidal thymos. The ultrasound follow-up was performed every 4-6 months. The ultrasound characteristics of the lesions (location, laterality, size and shape), the indi cation of the ultrasound scan and the follow-up time were analyzed. Results: Of 147 patients with thyroid nodules, we identified 12 children with lesions suggestive of an IET (8.1%). The mean age at diagnosis was 3.9 years (range 0-8). It was an incidental finding in all cases. Imaging findings were unilateral in eight patients and bilateral in four patients. All lesions were located in the mid and/or posterior portion of the gland. We adopted a watch-and-wait approach with ultrasound follow-up (mean 2.2 years; range 0.83-4) in all patients except in a 7-year-old boy who presented uncertain findings and underwent surgery, confirming IET in the pathological study. Conclusions: Thymic inclu sions in the thyroid gland are a rare but increasingly frequent finding, possibly related to the increased use of ultrasound studies. Pediatricians and radiologists should be aware of this entity to differentiate it from other thyroid lesions, avoiding unnecessary studies and/or treatments in these patients.

Resumen: Introducción: El timo ectópico intratiroideo (TEI) es una condición benigna poco frecuente, causada por la mi gración aberrante del timo durante la embriogénesis. Por lo general, se diagnostica incidentalmente como un nódulo tiroideo. Objetivo: Reportar la localización intratiroidea del tejido tímico ectópico y describir los hallazgos ecográficos en niños. Pacientes y Método: Revisamos retrospectivamente los datos clínicos y ecografías de tiroides realizadas en niños con nódulo tiroideo desde enero de 2010 a agosto de 2017 en un hospital nacional pediátrico de tercer nivel. Fueron considerados timos intratiroideos las lesiones intratiroideas hipoecogénicas sólidas con múltiples tractos lineales o pun- tiformes hiperecogénicos que no modificaron sus características en el seguimiento. El seguimiento ecográfico fue realizado cada 4 - 6 meses. Se analizaron las características ecográficas de las lesiones (localización, lateralidad, tamaño y forma), la indicación de la ecografía y el tiempo de seguimiento. Resultados: De un total de 147 pacientes con nódulos tiroideos, identificamos 12 niños con lesiones sugestivas de TEI (8,1%). Edad media al diagnóstico: 3,9 años (rango 0-8). En todos los casos fue un hallazgo incidental. Las imágenes fueron unilaterales en ocho y bilaterales en cuatro pacientes. Todas las lesiones se ubicaron en la porción media y/o posterior de la glándula. Se adoptó una conducta expectante con seguimiento ecográfico (media 2,2 años; rango 0,83-4), excepto en un niño de 7 años con hallazgos inciertos, que fue operado, confirmándose TEI en el estudio anatomopatológico. Con clusiones: Las inclusiones tímicas intratiroideas son un hallazgo raro pero cada vez más frecuente, posiblemente relacionado con el mayor uso de la ultrasonografía. Los pediatras y especialistas en imágenes deben conocer esta entidad para diferenciarla de otras lesiones tiroideas, evitando estudios diagnósticos y/o tratamientos innecesarios en estos pacientes.

Carbon is an extremely versatile element and can generate a plethora of structures with distinct properties. Proposing new possible metastable allotropic structures for carbon has been the subject of increasing interest over the past few years. In this contribution, we present a new carbon allotrope, named ABF-Carbon, based on the connection of spiropentadiene molecular motif and sp3 carbon atoms. This new structure is a metastable carbon allotrope formed by 6 carbon atoms, being 2 sp2 and 4 sp3, in a body-centered tetragonal with space group (space group 119) and point group . By first-principles calculations using the density functional theory (DFT), we predict that this new structure is mechanically and structurally stable and presents thermal stability up to 900 K. The calculations also show that ABF-Carbon presents a direct bandgap of 2.39 eV and higher cohesive energy than other carbon allotropes, such as T-Carbon and Y-Carbon/1-diamondyne.

Abstract: Introduction: Globally, Acute Lymphoblastic Leukemia (ALL), represents more than 30% of all types of cancers in children aged between 0 and 9 years. In Peru, it has not been evaluated whether exclusive breastfee ding (EB) is a protective factor for ALL. Objective: To identify the protective and risk factors associa ted with acute lymphoblastic leukemia in children aged between 0 and 13 years in a national hospital in Lima, Peru. Patients and Method: Observational, analytical study, case-control design. 112 cases diagnosed with ALL and 229 controls were evaluated. The data were collected by interviews with the mothers of both groups. The magnitude of the association between ALL and EB was estimated using the odds ratio (OR) and multivariate logistic regression in Stata v 12. Results: 50.9% (57/112) of the cases and 51.5% (118/229) of the controls were male. The mean age of the cases was 6.7 ± 3.2 years and of the controls 5.7 ± 3.5 years. The mean age of the mothers of the cases was 35.9 ± 6.5 and of the controls was 34.1 ± 7.1 years. EB reduces the risk of ALL by 44% compared with those who did not receive it, OR 0.56, p = 0.017, 95% CI (0.35-0.90). Complete secondary education reduces the risk of ALL by 62%, OR 0.38 CI 95% (0.15-0.61). Conclusions: Exclusive breastfeeding and the mother’s complete secondary education are protective factors for the development of ALL in children and adolescents.

Resumen: Introducción: La leucemia linfoblástica aguda representa más del 30% de todos los tipos de cáncer en niños entre 0 y 9 años a nivel global. En el Perú, no se ha evaluado si la lactancia materna exclusiva es un fac tor protector para la leucemia linfoblástica. Objetivo: Identificar los factores protectores y de riesgo asociados a la leucemia linfoblástica aguda en niños y adolescentes entre 0 y 13 años en un hospital nacional, Lima, Perú. Pacientes y Método: Estudio observacional, analítico, diseño caso-control. Se evaluaron 112 casos con diagnóstico de leucemia linfoblástica y 229 controles. Los datos fueron re cogidos por entrevistas a las madres de ambos grupos. Se estimó la magnitud de la asociación entre la leucemia y la lactancia exclusiva mediante el odds ratio (OR) y regresión logística multivariado en Stata v 12. Resultados: El 50,9% (57/112) de los casos y el 51,5% (118/229) de los controles fueron del género masculino. La media de edad entre los casos fue 6,7 ± 3,2 años y entre los controles 5,7 ± 3,5 años. La media de edad de la madre entre los casos fue 35,9 ± 6,5 y entre los controles fue 34,1 ± 7,1 años. La lactancia materna exclusiva se asocia a menor riesgo de leucemia en un 44% respecto a aquellos que no tuvieron, OR 0,56, p = 0,017, IC 95% (0,35-0,90). La educación secundaria completa se asocia a menor riesgo de leucemia en un 62%, OR 0,38 IC 95% (0,15-0,61). Conclusiones: La lactancia materna exclusiva y la educación secundaria completa de la madre son factores asociados a menor riesgo de leucemia linfoblástica aguda en niños y en adolescentes.

Abstract This work evaluated the effect of grape juice, red wine and resveratrol in liver parameters of rats submitted to high-fat diet. Experimental model was conducted with groups of adult females Rattus norvegicus: control (CG); high-fat (HG); grape juice (JG); red wine (RW) and resveratrol solution (RG). The high-fat diet significantly altered hepatocytes and Kupffer cells in all treated groups. HG group presented severe steatosis followed hepatocyte ballooning and tissue damages. JG group minimized hepatic histological lesion caused by high-fat diet and WG group also induced steatosis and inflammation in hepatocytes, similar to HG. Still, resveratrol protected the tissue against fatty liver disease by reducing fat infiltration and inflammation, indicating possible therapeutic effects on the liver. Cell cycle analysis showed that HG promoted damage to the tissue, reducing the viable cell content and increasing apoptosis, even when associated with wine consumption or isolated resveratrol. However, JG protected the liver against cell damage generated by the diet. Consumption of grape juice, even associated with a high-fat diet, represents a promising protection of the liver against cellular damage, but red wine further affects the tissue, and resveratrol alone was able to reduce damage but did not minimize cellular damage to the liver.

Abstract Breast cancer is the most frequent and lethal neoplastic disease among women worldwide. Psidium Guajava is a promising functional food against cancer, owing to a variety of bioactive compounds. This study aimed to evaluate the anticarcinogenic potential of Pedro Sato (PS), Hitigio (HI) and Tsumori (TS) guava cultivars fruit pulp extracts in MDA-MB-435 and MCF-7 human breast cancer cells. The antioxidant capacity of the extracts and their effect on cell viability, cell cycle and apoptosis were assessed. Additionally, the concentration of carotenoids, total phenolics, ascorbic acid and other physicochemical parameters were evaluated. PS pulp extract showed the highest in vitro antioxidative activity by all tested methods, as well as the highest content of lycopene and total phenolics, while TS pulp extract presented the highest concentration of β-carotene. After 48 hours treatment, all guava cultivars’ extracts caused reduction of MDA-MB-435 and MCF-7 cells viability, with PS and HI being the most effective extracts. All guava extracts caused MDA-MB-435 and MCF-7 cell count reduction in G0/G1 and G2/M phases and increased apoptosis. The present results strongly suggest that guava pulp exerts antiproliferative effect on breast adenocarcinoma cells.

Abstract: The aquatic environment presents daily and/or seasonal variations in dissolved oxygen (DO) levels. Piava faces different DO levels in the water due to its distributional characteristics. The goal of this study was to describe the effects of low DO levels on plasma ion, biochemical and oxidative variables in piava juveniles. Fish were exposed to different DO levels, including 1.0, 2.0, 3.0, 4.0 and 5.0 mg L-1 of DO for 96 h, after which blood and tissue samples (liver, kidney, gill and muscle) were collected. The decrease in DO levels decreased plasma Na+, Cl-, K+ and NH3 levels as well as protein and glycogen levels in the liver, kidney and muscle; increased Na+/K+-ATPase activity in the gills and kidney as well as glucose and ammonia levels in the liver, kidney and muscle; and increased lactate levels in the kidney and muscle. Thiobarbituric acid-reacting substances, catalase and non-protein thiol levels decreased in the tissues of piavas exposed to low DO levels. It is concluded that piava can apparently cope with hypoxic conditions; however, low DO levels are a stressor, and the tolerance of piava to hypoxia involves iono-regulatory, metabolic and oxidative adjustments.

False Orobanche affects tobacco production in Cuba. Diseased plants development abundant shoot proliferation and tumour in the root, and they’re showing dwarfism and rickets. Cuban Black tobacco cultivars are susceptible to Nocardia sp., causal agent of this disease. The incorporation of resistance genes into Cuban cultivars through genetic improvement will be an important element in the strategy for integrated management of this disease. However, there were not known sources of resistance to the disease and there isn’t an available procedure for the assessment of potential resistance sources present in the tobacco germplasm of Cuba. The objective of this research is to develop a method of assessing the level of resistance to the causal agent of false Orobanche of tobacco germplasm accessions. Fourteen accessions of different species and types of tobacco were inoculated with T42 strain of Nocardia sp. From the showing of symptoms was developed an empiric visual scale for calculating the plant’s damage degree. Accessions were located into four levels of reaction (resistant, moderately resistant, moderately susceptible and susceptible) according to plant’s damage degree. Resistant genotypes were identified within the tobacco germplasm bank of Cuba. Also within susceptible evaluated cultivars , plants carrying resistance genes were found with which they could immediately begin a genetic improvement program by selection of pure lines

El falso Orobanche afecta a la producción tabacalera de Cuba. Las plantas afectadas desarrollan abundante proliferación de brotes y tumores en las raíces, muestran enanismo y raquitismo. Los cultivares de tabaco Negro cubano son susceptibles a Nocardia sp., agente causal de esta enfermedad. La incorporación de genes de resistencia a este agente fitopatógeno en los cultivares cubanos, mediante el mejoramiento genético tradicional, constituirá un elemento de peso en la estrategia de manejo integrado de esta enfermedad. Sin embargo, no se conocen fuentes de resistencia a la enfermedad dentro de Nicotiana spp., ni se dispone de un procedimiento para la búsqueda de estas fuentes en la amplia diversidad de accesiones presentes en el banco de germoplasma de tabaco de Cuba. El objetivo de esta investigación es desarrollar un procedimiento de evaluación del nivel de resistencia frente al agente causal del falso Orobanche de las accesiones del banco de germoplasma de tabaco de Cuba. Catorce accesiones de diferentes especies y tipos de tabaco fueron inoculadas con la cepa T42 de Nocardia sp. A partir de la manifestación de los síntomas se elaboró una escala visual empírica que permite calcular el grado de afectación de las plantas. En correspondencia con el grado de afectación se ubicaron las accesiones en cuatro niveles de reacción (resistente, moderadamente resistente, moderadamente susceptible y susceptible). Se identificaron accesiones resistentes a la enfermedad dentro del banco de germoplasma de tabaco de Cuba. También dentro de cultivares evaluados de susceptibles se encontraron plantas portadoras de genes de resistencia con las que se pudiera comenzar de inmediato un programa de mejoramiento genético por selección de líneas puras