Is Galleria mellonella model a good alternative to study virulence in Staphylococcus aureus from bovine mastitis?

Staphylococcus aureus is one of the agents of bovine mastitis of hardest control due to a complex pathogenesis comprising a variety of virulence factors, which ensures its persistence in the mammary gland, causing significant health and economic losses. Therefore, understanding the pathogenesis of this agent is imperative. Galleria mellonella has stood out as an invertebrate animal model for the study of infectious diseases that affect several hosts. This work aimed to evaluate G. mellonella larvae as an experimental model for the study of virulence phenotypes in an S. aureus population isolated from bovine mastitis. Thirty genetically divergent S. aureus strains were chosen based on PFGE analysis. After experimental infection, larvae survival rates, bacterial growth in hemolymph, melanization intensity of the dorsal vessel, and histological characteristics of the infected tissues were evaluated. The G. mellonella model showed a clear diversity in the S. aureus pathogenicity pattern, allowing the differentiation of strains with virulence phenotypes ranging from high to low degrees. Histological analysis confirmed that the strains tested were capable of inducing the formation of nodules and melanization spots in the dorsal vessels of the larvae in different magnitudes. The strains 16S-717, 19C-828, and 31S-1443 presented the highest virulence intensity among the bacteria tested and will be used further for the generation of S. aureus mutant populations to prospect genetic targets aimed to develop control strategies of bovine mastitis. Altogether, our results suggest that G. mellonella is an attractive and low-cost animal model for characterizing virulence phenotypes of large S. aureus populations.

Enhancing Methylene Blue Dye Removal using pyrolyzed Mytella falcata Shells: Characterization, Kinetics, Isotherm, and Regeneration through Photolysis and Peroxidation.

The potential of pyrolyzed Mytella falcata shells as an adsorbent for removing methylene blue dye molecules from aqueous solutions was investigated. The study found that the adsorbent produced at 600 °C of pyrolysis temperature, with an adsorbent mass of 0.5 g, particle diameter of 0.297-0.149 mm, and pH 12.0, demonstrated the highest dye molecule removal efficiency of 82.41%. The material's porosity was observed through scanning electron microscopy, which is favorable for adsorption, while Fourier-transform infrared spectroscopy and X-Ray diffraction analysis analyses confirmed the presence of calcium carbonate in the crystalline phases. The pseudo-second order model was found to be the best fit for the data, suggesting that the adsorption mechanism involves two steps: external diffusion and diffusion via the solid pores. The Redlich-Peterson isotherm model better represented the equilibrium data, and the methylene blue adsorption was found to be spontaneous, favorable, and endothermic. The hydrogen peroxide with UV oxidation was found to be the most efficient method of regeneration, with a regeneration percentage of 63% achieved using 600 mmol.L-1 of oxidizing agents. The results suggest that pyrolyzed Mytella falcata shells could serve as an ecologically viable adsorbent alternative, reducing the amount of waste produced in the local environment and at the same time removing pollutants from the water. The material's adsorption capacity remained almost constant in the first adsorption-oxidation cycles, indicating its potential for repeated use.

Effect of the transition program on self-care of patients with heart failure: a randomized clinical trial / Efecto del programa de transición en el autocuidado de pacientes con insuficiencia cardíaca: ensayo clínico aleatorizado / Efeito do programa de transição no autocuidado de pacientes com insuficiência cardíaca: ensaio clínico randomizado

ABSTRACT Objective: analyze the effect of transitional care on self-care, quality of life and knowledge of disease of patients admitted with heart failure. Method: this is a blind randomized clinical trial with 74 patients with heart failure in two quaternary hospitals in Rio de Janeiro-RJ between December 2017 and February 2020. The intervention group received transitional care with educational management by a nurse at the bedside from admission until hospital discharge and telephone consultation for 30 days after discharge. The control group received usual follow-up. The primary outcomes included maintenance skills, management and confidence in self-care, and the secondary outcomes included quality of life and knowledge of disease. Both were assessed using questionnaires validated for use in Brazil. Data were analyzed by repeated measures ANOVA. Results: the intervention group had higher scores for maintenance (74.3 vs 44.2; p<0.001) and self-care confidence (79.3 vs 56.4; p<0.001) and knowledge of disease (41.3 vs 27.5; p<0.001) and lower quality of life scores (42.1 vs 64.5; p<0.001) 30 days after discharge. Conclusion: transitional care was effective in improving quality of life, knowledge of disease, maintenance and confidence in self-care. This study was registered in the Brazilian Clinical Trials Registry, under RBR-2dpc6b.

RESUMEN Objetivo: analizar el efecto de los cuidados transicionales sobre el autocuidado, la calidad de vida e y el conocimiento de la enfermedad de pacientes hospitalizados con insuficiencia cardíaca. Método: ensayo clínico aleatorio ciego con 74 pacientes con insuficiencia cardíaca en dos hospitales cuaternarios de Río de Janeiro-RJ entre diciembre de 2017 y febrero de 2020. El grupo de intervención recibió cuidados de transición con manejo educativo por parte de una enfermera al lado de la cama desde el ingreso hasta el alta hospitalaria y Consulta telefónica durante 30 días después del alta. El grupo de control recibió el seguimiento habitual. Los resultados primarios incluyeron habilidades de mantenimiento, gestión y confianza en el autocuidado, y los resultados secundarios incluyeron calidad de vida y conocimiento de la enfermedad. Ambos fueron evaluados mediante cuestionarios validados para su uso en Brasil. Los datos fueron analizados mediante ANOVA de medidas repetidas. Resultados: el grupo de intervención tuvo puntuaciones más altas en mantenimiento (74,3 vs 44,2; p<0,001) y confianza en el autocuidado (79,3 vs 56,4; p<0,001) y conocimiento de la enfermedad (41,3 vs 27,5; p<0,001)y puntuaciones de calidad de vida más bajas (42,1 frente a 64,5; p<0,001) 30 días después del alta. Conclusión: la atención de transición fue eficaz para mejorar la calidad de vida, el conocimiento de la enfermedad, el mantenimiento y la confianza en el autocuidado. Estudio inscrito en el Registro Brasileño de Ensayos Clínicos, con el número RBR-2dpc6b.

RESUMO Objetivo: analisar o efeito do cuidado de transição no autocuidado, qualidade de vida e conhecimento da doença de pacientes hospitalizados com insuficiência cardíaca. Método: ensaio clínico randomizado cego com 74 pacientes com insuficiência cardíaca em dois hospitais quaternários do Rio de Janeiro-RJ, entre dezembro de 2017 e fevereiro de 2020. O grupo intervenção recebeu cuidados de transição com gerenciamento educativo por enfermeira, à beira do leito, desde a admissão até a alta hospitalar e consulta telefônica por 30 dias após a alta. O grupo controle recebeu acompanhamento usual. Os desfechos primários incluíram habilidades de manutenção, manejo e confiança no autocuidado, e os desfechos secundários, qualidade de vida e conhecimento da doença. Ambos foram avaliados por questionários validados para uso no Brasil. Os dados foram analisados pelo ANOVA de medidas repetidas. Resultados: o grupo intervenção apresentou maiores escores para manutenção (74,3 vs44,2; p<0,001) e confiança do autocuidado (79,3 vs56,4; p<0,001) e conhecimento da doença (41,3 vs27,5; p<0,001) e menores escores de qualidade de vida (42,1 vs64,5; p<0,001) em 30 dias após a alta. Conclusão: o cuidado de transição foi efetivo na melhora da qualidade de vida, conhecimento da doença, manutenção e confiança no autocuidado. Estudo registrado no Registro Brasileiro de Ensaios Clínicos, sob o número RBR-2dpc6b.

Inactivation of isolated fungi on Erythrina velutina Willd. seeds through atmospheric plasma

Abstract This study aimed to evaluate the effect of atmospheric plasma application on the inactivation of fungi on the surface of Erythrina velutina seeds and on isolated fungal colonies. Two experiments were conducted using a completely randomized design. First, plasma was applied to the surface of the seeds using helium gas and atmospheric plasma for 3, 6, and 9 min in addition to the control (untreated seeds), constituting seven treatments with five repetitions each. In the second experiment, Petri dishes containing the inoculum of different fungi were treated with atmospheric air plasma for 3, 6, and 9 min (Air-3, Air-6, and Air-9) and were compared with untreated fungi in Petri dishes without treatment (control), totaling four treatments and five repetitions each. We found that the application of atmospheric air plasma to E. velutina seeds for 9 min had an antimicrobial effect on the fungi Aspergillus niger, Aspergillus flavus, Fusarium sp., Brachysporium sp., and Rhizopus sp. The formation of fungal colonies isolated from E. velutina seeds was also inhibited by 3 min of exposure to atmospheric air plasma, except for A. niger, whose inhibition occurred after 6 min of exposure to atmospheric plasma.

Resumo Este trabalho teve como objetivo avaliar o efeito da aplicação de plasma atmosférico na inativação de fungos na superfície de sementes de Erythrina velutina e em colônias fúngicas isoladas. Dois experimentos foram realizados em delineamento inteiramente casualizado: no primeiro, o plasma foi aplicado na superfície das sementes usando gás hélio e plasma atmosférico por três, seis e nove minutos, além do controle (sementes sem tratamento), constituindo sete tratamentos com cinco repetições cada; no segundo experimento, placas de Petri contendo o inóculo de diferentes fungos foram tratadas com plasma atmosférico por três, seis e nove minutos (Air-3, Air-6 e Air-9) e comparadas com fungos não tratados em placas de Petri sem tratamento (controle), totalizando quatro tratamentos e cinco repetições cada. Descobrimos que a aplicação de plasma atmosférico nas sementes de E. velutina por nove minutos teve efeito antimicrobiano sobre os fungos Aspergillus niger, Aspergillus flavus, Fusarium sp., Brachysporium sp. e Rhizopus sp. A formação de colônias fúngicas isoladas de sementes de E. velutina também foi inibida por três minutos de exposição à aplicação de plasma atmosférico, exceto para A. niger, cuja inibição ocorreu a partir de 6 minutos de exposição à aplicação de plasma atmosférico.

Inactivation of isolated fungi on Erythrina velutina Willd. seeds through atmospheric plasma / Inativação de fungos isolados em sementes de Erythrina velutina Willd. por meio do plasma atmosférico

Abstract This study aimed to evaluate the effect of atmospheric plasma application on the inactivation of fungi on the surface of Erythrina velutina seeds and on isolated fungal colonies. Two experiments were conducted using a completely randomized design. First, plasma was applied to the surface of the seeds using helium gas and atmospheric plasma for 3, 6, and 9 min in addition to the control (untreated seeds), constituting seven treatments with five repetitions each. In the second experiment, Petri dishes containing the inoculum of different fungi were treated with atmospheric air plasma for 3, 6, and 9 min (Air-3, Air-6, and Air-9) and were compared with untreated fungi in Petri dishes without treatment (control), totaling four treatments and five repetitions each. We found that the application of atmospheric air plasma to E. velutina seeds for 9 min had an antimicrobial effect on the fungi Aspergillus niger, Aspergillus flavus, Fusarium sp., Brachysporium sp., and Rhizopus sp. The formation of fungal colonies isolated from E. velutina seeds was also inhibited by 3 min of exposure to atmospheric air plasma, except for A. niger, whose inhibition occurred after 6 min of exposure to atmospheric plasma.

Resumo Este trabalho teve como objetivo avaliar o efeito da aplicação de plasma atmosférico na inativação de fungos na superfície de sementes de Erythrina velutina e em colônias fúngicas isoladas. Dois experimentos foram realizados em delineamento inteiramente casualizado: no primeiro, o plasma foi aplicado na superfície das sementes usando gás hélio e plasma atmosférico por três, seis e nove minutos, além do controle (sementes sem tratamento), constituindo sete tratamentos com cinco repetições cada; no segundo experimento, placas de Petri contendo o inóculo de diferentes fungos foram tratadas com plasma atmosférico por três, seis e nove minutos (Air-3, Air-6 e Air-9) e comparadas com fungos não tratados em placas de Petri sem tratamento (controle), totalizando quatro tratamentos e cinco repetições cada. Descobrimos que a aplicação de plasma atmosférico nas sementes de E. velutina por nove minutos teve efeito antimicrobiano sobre os fungos Aspergillus niger, Aspergillus flavus, Fusarium sp., Brachysporium sp. e Rhizopus sp. A formação de colônias fúngicas isoladas de sementes de E. velutina também foi inibida por três minutos de exposição à aplicação de plasma atmosférico, exceto para A. niger, cuja inibição ocorreu a partir de 6 minutos de exposição à aplicação de plasma atmosférico.

Self-care nursing interventions: A qualitative study into electronic health records' contents.

AIMS: This study aims to (1) analyse all self-care-related interventions Portuguese nurses documented, (2) determine potential issues that may impair semantic interoperability and (3) propose a new set of interventions representing nursing actions regarding self-care that may integrate any HER application. BACKGROUND: As populations age and chronic diseases increase, self-care concerns rise. Individuals who seek healthcare, regardless of context, need prompt access to accurate health information. Healthcare professionals need to understand the information in all places where care is provided, creating the need for semantic interoperability within electronic health records. METHODS: A qualitative descriptive and exploratory study was conducted in two phases: (1) a content analysis of nursing interventions e-documentation and (2) a focus group with fifteen registered nurses exploring latent criteria or insights gleaned from the findings of content analysis. The COREQ statement was used to guide research reporting. RESULTS: We extracted 1529 nursing intervention sentences from the electronic health records and created 209 intervention categories. We identified the main issues with semantic interoperability in nursing intervention identification. CONCLUSION: According to the findings, nurses cooperate with clients, offering physical aid and encouraging them to overcome functional limitations to self-care tasks hampered by their conditions. IMPLICATIONS FOR NURSING POLICY AND HEALTH POLICY: This article provides evidence to warn policy makers against decisions to use locally customised electronic health records, as well as evidence on the importance of policy promoting the adoption of a nursing ontology for electronic health records. And, as a result, the harmonisation and effective provision of high-quality nursing care and the reduction of healthcare costs across nations.

Cuidados omissos em contexto de cuidados domiciliários: Razões na perspetiva dos enfermeiros / Nurses' perspectives on the reasons for missed care in home care settings / Cuidados omitidos en la atención domiciliaria: Razones desde la perspectiva de los enfermeros

Resumo Enquadramento: Os cuidados às pessoas dependentes no autocuidado a viver no domicílio e a sua provisão são uma realidade complexa e multidimensional, não estando em muitas situações garantida a sua completude. São escassos os estudos que analisam as razões deste fenómeno. Objetivo: Conhecer as razões que, na perspetiva dos enfermeiros, subjazem à existência de cuidados que não são realizados ou que não são realizados com a frequência esperada às pessoas dependentes referenciadas para cuidados pelas equipas de cuidados continuados domiciliários. Metodologia: Estudo de natureza qualitativa com recurso à técnica do focus group. Resultados: Os cuidados incompletos são concetualizados pelos enfermeiros como um fenómeno que se inicia num problema - escassez de recursos/tempo - associado a fatores organizacionais e condições da família para o exercício do papel de cuidador, que leva à decisão de priorizar cuidados resultando em cuidados omissos ou incompletos. Este é um processo que gera mal-estar nos enfermeiros. Conclusão: É necessário um modelo de cuidados domiciliários que dê resposta em completude às necessidades.

Abstract Background: The delivery of care to people who live at home and depend on others for care is a complex and multidimensional reality where there are often situations of unfinished care. Few studies analyze the reasons for this phenomenon. Objective: To explore nurses' perspectives on the reasons for missed care or care that is not provided as frequently as expected to dependent people referred to home-based long-term care teams. Methodology: Qualitative study using the focus group technique. Results: Nurses conceptualize unfinished care as a phenomenon that starts with a problem - lack of resources/time - associated with organizational factors and the family's conditions to assume the caregiver role, which leads to the decision to prioritize care resulting in missed or unfinished care. This process causes discomfort among nurses. Conclusion: There is a need for a home care model that fully meets the needs.

Resumen Marco contextual: Los cuidados que se prestan a las personas dependientes en el autocuidado que viven en su domicilio es una realidad compleja y multidimensional, y en muchas situaciones no se garantiza que sea completa. Hay pocos estudios que analicen las razones de este fenómeno. Objetivo: Conocer las razones que, desde la perspectiva de los enfermeros, subyacen a la existencia de cuidados que no se prestan o que no se prestan con la frecuencia esperada a las personas dependientes derivadas por los equipos de atención continuada a domicilio. Metodología: Estudio cualitativo llevado a cabo mediante la técnica del grupo focal. Resultados: Los cuidados incompletos son conceptualizados por los enfermeros como un fenómeno que parte de un problema - la falta de recursos/tiempo - asociado a factores organizativos y a las condiciones familiares para el ejercicio del papel del cuidador, lo que lleva a la decisión de priorizar los cuidados, que se traduce en una falta de cuidados omitidos o incompletos. Este es un proceso que genera malestar en los profesionales. Conclusión: Es necesario un modelo de atención domiciliaria que satisfaga plenamente las necesidades.

Magnetic Zinc Oxide/Manganese Ferrite Composite for Photodegradation of the Antibiotic Rifampicin.

In this study, a composite of zinc oxide and manganese ferrite was synthesized using co-precipitation and hydrothermal routes, to be used as photocatalysts in reactions with UV/Vis light source. The synthesized materials were characterized by FTIR, XRD, and SEM, where it was possible to verify the efficiency of the syntheses performed, through the identification of the resulting phases, the evaluation of the structural morphology of the particles, and the analysis of the detachments of the main vibration bonds present in these materials. The composite ZnO/MnFe2O4 was used in photodegradation reactions of the antibiotic rifampicin, with catalyst dosage of 0.20; 0.40, and 0.60 g and 10 ppm of rifampicin, reactions using pure ZnO as a catalyst were also performed as a comparative parameter of the influence of MnFe2O4 in this system. The composite ZnO/MnFe2O4 showed a maximum percentage of rifampicin decontamination of 94.72% and ZnO, 74.20%using 0.20 g of photocatalyst after 90 min, which indicates a positive influence on this process. The solution treated with ZnO/MnFe2O4 was subjected to magnetic field induction for attraction and consequently accelerated removal of the solids present, successfully, compacting for the application of ZnO/MnFe2O4 to be presented as a promising material for decontamination of emerging pollutants through photocatalytic reactions.

Nursing knowledge of people with paresis of voluntary muscles: a living scoping review protocol.

OBJECTIVE: This review aims to continuously map the nursing knowledge about people with paresis of voluntary muscles in any context of care. INTRODUCTION: Muscle paresis is a condition that significantly impacts quality of life. Nurses have a crucial role in managing this condition, particularly paresis of voluntary movement muscles. However, nursing knowledge about patients with paresis of voluntary muscles is dispersed, hampering the integration of evidence within the structure of information systems. Mapping how the nursing process components are identified is the first step in creating a Nursing Clinical Information Model for this condition, capable of integrating evidence into information systems. INCLUSION CRITERIA: This scoping review will consider studies focusing on the nursing process regarding people with paresis of voluntary muscles in all care contexts. The review will include quantitative, qualitative, and mixed-methods study designs, systematic reviews, clinical guidelines, dissertations, and theses. METHODS: The review process will follow JBI's scoping review guidance, as well as the Cochrane Collaboration's guidance on living reviews. Screening of new literature will be performed regularly, with the review being updated according to new findings. The search strategy will map published and unpublished studies. The databases to be searched will include MEDLINE, CINAHL, Scopus, JBI Evidence Synthesis , and the Cochrane Central Register of Controlled Trials. Searches for unpublished studies will include OpenGrey and Repositorios Científicos de Acesso Aberto de Portugal. Studies published in English and Portuguese from 1975 will be considered for inclusion. REGISTRATION: Open Science Framework: https://osf.io/d7c9g/.

Hybrid odontogenic lesions: A systematic review of 203 cases reported in the literature.

BACKGROUND: Hybrid odontogenic lesions combine histopathological characteristics of two or more odontogenic cysts and/or tumours. The aim of this study was to evaluate the available data on hybrid odontogenic lesions (HOL) and to analyse their epidemiological/clinical features and biological behaviour. METHODS: An electronic search was done in January 2021 using multiple databases. Eligibility criteria encompassed publications with sufficient clinical and histological information to confirm the tumours' diagnoses. RESULTS: A total of 147 articles were included in this study, comprising 203 cases. Calcifying odontogenic cyst associated with odontoma (COC/OD) (37/18.2%) was the most common HOL. Females were more affected with a mean age of 24.9 years. Lesions presented as asymptomatic swellings, with a mean evolution time of 8.2 months (0.3-96), and mean tumour size of 4.8 cm (0.3-7). Radiographic aspects frequently showed radiolucent (139/68.4%) and unilocular (52/25.6%) images with well-defined limits (48/23.6%). The lesions mostly affected mandibular pre-molars (69/34%) and mandibular molars (69/34%) regions. Enucleation (89/43.8%) and surgical excision (59/29%) were the most common treatment modalities. The mean follow-up time was 33.8 months (0.5-216 months) and recurrences were observed in four cases (1.9%), all of which were central odontogenic fibroma associated with central giant cell granuloma (COF/CGCG). CONCLUSION: COC/OD is the most common HOL and recurrence is a rare event, being usually associated with the diagnosis of COF/CGCG.

Nursing knowledge on skin ulcer healing: a living scoping review protocol.

OBJECTIVE: This review aims to continuously map the nursing knowledge on skin ulcer healing in any context of care. INTRODUCTION: Chronic wounds are an increasing concern for society and health care providers. Pressure ulcers and venous ulcers, among others, have devastating effects on morbidity and quality of life and require a systematic approach. The nursing process is an important method that allows a better organization and overall care quality for a systematic and continuous professional approach to nursing management of skin ulcers. The integration of this nursing knowledge in informatics systems creates an opportunity to embed decision-support models in clinical activity, promoting evidence-based practice. INCLUSION CRITERIA: This scoping review will consider articles on nursing data, diagnosis, interventions, and outcomes focused on people with skin ulcers in all contexts of care. This review will include quantitative, qualitative, and mixed methods study designs as well as systematic reviews and dissertations. METHODS: JBI's scoping review guidance, as well as the Cochrane Collaboration's guidance on living reviews, will be followed to meet the review's objective. Screening of new literature will be performed regularly, with the review updated according to new findings. The search strategy will map published and unpublished studies. The databases to be searched include MEDLINE, CINAHL, Scopus, JBI Evidence Synthesis, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and PEDro. Searches for unpublished studies will include OpenGrey and Repositórios Científicos de Acesso Aberto de Portugal. Studies published in English and Portuguese since 2010 will be considered for inclusion. SCOPING REVIEW PROTOCOL REGISTRATION: Open Science Framework: https://osf.io/f6s4e/.

Laparoscopic Pancreatectomy in Rats: The Development of an Experimental Model.

INTRODUCTION: several pancreatectomy techniques in rats have been described and utilized for research concerning the pancreas endocrine and exocrine functions. However, we did not find a description of any kind of laparoscopic pancreatectomy in rats in the consulted databases. The objective of this study is to describe a laparoscopic splenic lobe pancreatectomy in rats. METHODS: ten Wistars rats weighting more then 300 g were operated for standardizing the laparoscopic pancreatosplenectomy technique, aided by previous descriptions of laparoscopic splenectomy and open pancreatectomy in rats. Adjustments have been progressively adopted for technical refinement. RESULTS: In five animals a low-cost rat laparoscopic set was used. In other five animals we used a standard laparoscopic set. Three rats died early due to different causes: transection of the gastroesophageal junction, hemorrhagic shock and inadvertent colonic injury. The postoperative period of the other seven rats was uneventful until the seventh postoperative day. DISCUSSION: laparoscopic distal pancreatectomy and splenectomy in rats is feasible and safe, even with a low-cost set, in which the results were alike the standard laparoscopic set.

Developing nursing clinical data models addressing delusion and hallucination with Meleis transitions theory as the theoretical reference model: A focus group study.

PURPOSE: To build the final clinical data models regarding the nursing focuses "Delusion" and "Hallucination" with Meleis transitions theory as the theoretical reference model. DESIGN AND METHODS: A qualitative descriptive design was adopted, using two focus groups. FINDINGS: The clinical data models obtained by this study recognize a perspective centered on the client's transition, which emphasizes the role of nursing in relation to a client suffering from delusion and hallucination. IMPLICATIONS FOR NURSING PRACTICE: These clinical data models may contribute towards improving nursing clinical decision-making and nursing care quality regarding these areas.

Osmoprotection in Salvia hispanica L seeds under water stress attenuators / Osmoproteção em sementes de Salvia hispanica L sob atenuadores do estresse hídrico

Salvia hispanica cultivation is recent in Brazil and occurs in the off-season, when there is lower water availability in the soil. Water deficit is one of the abiotic factors that most limit germination for compromising the sequence of metabolic events that culminate with seedling emergence. Several attenuating substances have been used to mitigate the effects resulting from this stress and give higher tolerance to the species. Thus, the objective of this study was to evaluate the action of different agents as water stress attenuators in the germination and accumulation of organic compounds in S. hispanica seedlings. The treatments consisted of pre-soaking the seeds for 4 hours in salicylic acid (1 mM.L-¹), gibberellic acid (0.4 mM.L-¹), distilled water and control treatment (without soaking). The seeds were germinated at osmotic potentials of 0.0, -0.1, -0.2, -0.3 and -0.4 MPa, using PEG 6000 as an osmotic agent. The variables germination percentage, germination speed index, shoot and primary root lengths, total dry mass, proline, total soluble sugars and total free amino acids were analyzed. Salicylic acid and gibberellic acid led to the best results among the attenuators tested, increasing germination, length, dry mass and biochemical components of S. hispanica seedlings under water deficit. Therefore, salicylic and gibberellic acids are efficient in mitigating water stress in S. hispanica seeds up to the potential of -0.4 MPa.

O cultivo da Salvia hispanica é recente no Brasil e se dá no período de entressafra, quando há menor disponibilidade hídrica no solo. O déficit hídrico é um dos fatores abióticos que mais limitam a germinação por comprometer a sequência de eventos metabólicos que culminam com a emergência da plântula. Diversas substâncias atenuadoras têm sido empregadas com a finalidade de mitigar os efeitos resultantes desse estresse e conferir maior tolerância às espécies. Desse modo, objetivou-se avaliar a ação de diferentes agentes como atenuadores do estresse hídrico na germinação e acúmulo de compostos orgânicos em plântulas de S. hispanica. Os tratamentos consistiram na pré-embebição das sementes durante 4 horas em ácido salicílico (1 mM.L-¹), ácido giberélico (0,4 mM.L-¹), água destilada e o tratamento controle (sem embebição). As sementes foram germinadas sob os potenciais osmóticos 0,0, -0,1, -0,2, -0,3 e -0,4 MPa, utilizando PEG 6000 como agente osmótico. Analisaram-se as variáveis porcentagem de germinação, índice de velocidade de germinação, comprimento da parte aérea e da raiz primária, massa seca total, prolina, açúcares solúveis totais e aminoácidos livres totais. O ácido salicílico e o ácido giberélico apresentaram os melhores resultados, dentre os atenuadores testados, incrementando a germinação, o comprimento, a massa seca e os componentes bioquímicos de plântulas de S. hispanica sob déficit hídrico. Logo, os ácidos salicílico e giberélico são eficientes na mitigação do estresse hídrico em sementes de S. hispanica até o potencial -0,4 MPa.

Ionic homeostasis, biochemical components and yield of Italian zucchini under nitrogen forms and salt stress / Homeostase iônica, componentes bioquímicos e produção da abobrinha italiana sob formas de nitrogênio e estresse salino

This research was carried out aiming at evaluating the effects of nitrate and ammonium ions on nutrient accumulation, biochemical components and yield of Italian zucchini (cv. Caserta) grown in a hydroponic system under salt stress conditions. The experiment was carried out in a greenhouse utilizing an experimental design in randomized blocks, arranged in a 2 x 5 factorial scheme, with 4 replications. The treatments consisted of two forms of nitrogen (nitrate - NO3- and ammonium - NH4+) and 5 electrical conductivity levels of irrigation water (ECw) (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1). The analysis of the results indicated that supply of N exclusively in NH4+ form promotes greater damage to the leaf membrane and reduction in accumulation of macronutrients and higher Na+/K+, Na+/Ca++ and Na+/Mg++ ratios in the shoots of zucchini plants. Electrical conductivity of irrigation water above 2.0 dS m-¹ reduces the accumulation of nutrients in shoot and yield of Italian zucchini plant. The toxicity of NH4+ under Italian zucchini plants overlap the toxicity of the salinity, since its fertilization exclusively with this form of nitrogen inhibits its production, being the NO3- form the most suitable for the cultivation of the species.

Este trabalho foi desenvolvido com o objetivo de avaliar os efeitos dos íons nitrato e amônio sobre o acúmulo de nutrientes e produção da abobrinha italiana (cv. Caserta) cultivada em sistema hidropônico sob estrese salino. O experimento foi conduzido em casa de vegetação utilizando o delineamento experimental em blocos casualizados, arranjados em esquema fatorial 2 x 5, com 4 repetições. Os tratamentos foram constituídos de duas formas de nitrogênio (nitrato - NO3- e amônio - NH4+) e cinco níveis de condutividade elétrica da água de irrigação (CEa) (0,5; 2,0; 3,5; 5,0 e 6,5 dS m-¹). As análises dos resultados indicaram que suprimento de N exclusivamente em forma de NH4+ promove maiores danos na membrana foliar e redução no acúmulo de macronutrientes e maiores relações Na+/K+, Na+/Ca++ e Na+/Mg++ na parte aérea das plantas de abobrinha. A irrigação com água a cima de 2,0 dS m-¹ reduz o acúmulo de nutrientes na parte aérea das plantas e a produção de abobrinha. A toxicidade do NH4+ sob abobrinha italiana sobrepõe-se à toxicidade da salinidade, pois a fertilização exclusiva com esta forma de nitrogênio inibe sua produção, sendo a forma NO3- a mais adequada para o cultivo da espécie.

Osmoprotection in Salvia hispanica L. seeds under water stress attenuators

Abstract Salvia hispanica cultivation is recent in Brazil and occurs in the off-season, when there is lower water availability in the soil. Water deficit is one of the abiotic factors that most limit germination for compromising the sequence of metabolic events that culminate with seedling emergence. Several attenuating substances have been used to mitigate the effects resulting from this stress and give higher tolerance to the species. Thus, the objective of this study was to evaluate the action of different agents as water stress attenuators in the germination and accumulation of organic compounds in S. hispanica seedlings. The treatments consisted of pre-soaking the seeds for 4 hours in salicylic acid (1 mM.L-1), gibberellic acid (0.4 mM.L-1), distilled water and control treatment (without soaking). The seeds were germinated at osmotic potentials of 0.0, -0.1, -0.2, -0.3 and -0.4 MPa, using PEG 6000 as an osmotic agent. The variables germination percentage, germination speed index, shoot and primary root lengths, total dry mass, proline, total soluble sugars and total free amino acids were analyzed. Salicylic acid and gibberellic acid led to the best results among the attenuators tested, increasing germination, length, dry mass and biochemical components of S. hispanica seedlings under water deficit. Therefore, salicylic and gibberellic acids are efficient in mitigating water stress in S. hispanica seeds up to the potential of -0.4 MPa.

Resumo O cultivo da Salvia hispanica é recente no Brasil e se dá no período de entressafra, quando há menor disponibilidade hídrica no solo. O déficit hídrico é um dos fatores abióticos que mais limitam a germinação por comprometer a sequência de eventos metabólicos que culminam com a emergência da plântula. Diversas substâncias atenuadoras têm sido empregadas com a finalidade de mitigar os efeitos resultantes desse estresse e conferir maior tolerância às espécies. Desse modo, objetivou-se avaliar a ação de diferentes agentes como atenuadores do estresse hídrico na germinação e acúmulo de compostos orgânicos em plântulas de S. hispanica. Os tratamentos consistiram na pré-embebição das sementes durante 4 horas em ácido salicílico (1 mM.L-1), ácido giberélico (0,4 mM.L-1), água destilada e o tratamento controle (sem embebição). As sementes foram germinadas sob os potenciais osmóticos 0,0, -0,1, -0,2, -0,3 e -0,4 MPa, utilizando PEG 6000 como agente osmótico. Analisaram-se as variáveis porcentagem de germinação, índice de velocidade de germinação, comprimento da parte aérea e da raiz primária, massa seca total, prolina, açúcares solúveis totais e aminoácidos livres totais. O ácido salicílico e o ácido giberélico apresentaram os melhores resultados, dentre os atenuadores testados, incrementando a germinação, o comprimento, a massa seca e os componentes bioquímicos de plântulas de S. hispanica sob déficit hídrico. Logo, os ácidos salicílico e giberélico são eficientes na mitigação do estresse hídrico em sementes de S. hispanica até o potencial -0,4 MPa.

Ionic homeostasis, biochemical components and yield of Italian zucchini under nitrogen forms and salt stress

Abstract This research was carried out aiming at evaluating the effects of nitrate and ammonium ions on nutrient accumulation, biochemical components and yield of Italian zucchini (cv. Caserta) grown in a hydroponic system under salt stress conditions. The experiment was carried out in a greenhouse utilizing an experimental design in randomized blocks, arranged in a 2 x 5 factorial scheme, with 4 replications. The treatments consisted of two forms of nitrogen (nitrate - NO3- and ammonium - NH4+) and 5 electrical conductivity levels of irrigation water (ECw) (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1). The analysis of the results indicated that supply of N exclusively in NH4+ form promotes greater damage to the leaf membrane and reduction in accumulation of macronutrients and higher Na+/K+, Na+/Ca++ and Na+/Mg++ ratios in the shoots of zucchini plants. Electrical conductivity of irrigation water above 2.0 dS m-1 reduces the accumulation of nutrients in shoot and yield of Italian zucchini plant. The toxicity of NH4+ under Italian zucchini plants overlap the toxicity of the salinity, since its fertilization exclusively with this form of nitrogen inhibits its production, being the NO3- form the most suitable for the cultivation of the species.

Resumo Este trabalho foi desenvolvido com o objetivo de avaliar os efeitos dos íons nitrato e amônio sobre o acúmulo de nutrientes e produção da abobrinha italiana (cv. Caserta) cultivada em sistema hidropônico sob estrese salino. O experimento foi conduzido em casa de vegetação utilizando o delineamento experimental em blocos casualizados, arranjados em esquema fatorial 2 x 5, com 4 repetições. Os tratamentos foram constituídos de duas formas de nitrogênio (nitrato - NO3- e amônio - NH4+) e cinco níveis de condutividade elétrica da água de irrigação (CEa) (0,5; 2,0; 3,5; 5,0 e 6,5 dS m-1). As análises dos resultados indicaram que suprimento de N exclusivamente em forma de NH4+ promove maiores danos na membrana foliar e redução no acúmulo de macronutrientes e maiores relações Na+/K+, Na+/Ca++ e Na+/Mg++ na parte aérea das plantas de abobrinha. A irrigação com água a cima de 2,0 dS m-1 reduz o acúmulo de nutrientes na parte aérea das plantas e a produção de abobrinha. A toxicidade do NH4+ sob abobrinha italiana sobrepõe-se à toxicidade da salinidade, pois a fertilização exclusiva com esta forma de nitrogênio inibe sua produção, sendo a forma NO3- a mais adequada para o cultivo da espécie.