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ABSTRACT Introduction: The immune response to different Coronavirus Disease 2019 (COVID-19) vaccines is under-investigated in end-stage kidney disease (ESKD) patients, especially in the Middle East and North Africa. We carried out this research to estimate the effectiveness of COVID-19 immunization in ESKD patients on regular hemodialysis (HD). Methods: In this prospective observational study, we enrolled 60 ESKD patients on regular HD who had completed COVID-19 vaccination and 30 vaccinated healthy participants. Serum levels of severe acute respiratory syndrome coronavirus 2 immunoglobulin G (SARS-COV2 IgG) were quantified 1 month after completing the vaccination schedule, and all participants were followed up from October 2021 to March 2022. The vaccines used in the study were from Pfizer-BioNTech, AstraZeneca, and Sinopharm. Results: The median level of SARS-COV2 IgG was lower in HD patients than in healthy participants (p < 0.001). Regarding the type of COVID-19 vaccination, there was no statistical difference in SARS-COV2 IgG levels among HD patients. During the observation period, none of the HD patients had COVID-19. Conclusion: COVID-19 vaccination appeared to be protective in HD patients for 6 months and the side effects of vaccines were tolerable.

RESUMO Introdução: A resposta imune a diferentes vacinas contra a doença do coronavírus 2019 (COVID-19) é pouco investigada em pacientes com doença renal em estágio terminal (DRET), especialmente no Oriente Médio e norte da África. Realizamos esta pesquisa para estimar a eficácia da imunização contra a COVID-19 em pacientes com DRET em hemodiálise regular (HD). Métodos: Nesse estudo observacional prospectivo, inscrevemos 60 pacientes com DRET em HD regular que haviam concluído o esquema de vacinação contra a COVID-19 e 30 participantes saudáveis vacinados. Os níveis séricos de imunoglobulina G da síndrome respiratória aguda grave do coronavírus 2 (SARS-COV2 IgG) foram quantificados um mês após a conclusão do esquema vacinal, e todos os participantes foram acompanhados de outubro de 2021 a março de 2022. As vacinas utilizadas no estudo eram da Pfizer-BioNTech, AstraZeneca e Sinopharm. Resultados: O nível mediano de SARS-COV2 IgG foi menor em pacientes em HD do que em participantes saudáveis (p < 0,001). Com relação ao tipo de vacinação contra a COVID-19, não houve diferença estatística nos níveis de SARS-COV2 IgG entre pacientes em HD. Durante o período de observação, nenhum dos pacientes em HD teve COVID-19. Conclusão: A vacinação contra a COVID-19 pareceu ser eficaz na proteção de pacientes em HD por 6 meses e os efeitos colaterais das vacinas foram toleráveis.

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INTRODUCTION: The immune response to different Coronavirus Disease 2019 (COVID-19) vaccines is under-investigated in end-stage kidney disease (ESKD) patients, especially in the Middle East and North Africa. We carried out this research to estimate the effectiveness of COVID-19 immunization in ESKD patients on regular hemodialysis (HD). METHODS: In this prospective observational study, we enrolled 60 ESKD patients on regular HD who had completed COVID-19 vaccination and 30 vaccinated healthy participants. Serum levels of severe acute respiratory syndrome coronavirus 2 immunoglobulin G (SARS-COV2 IgG) were quantified 1 month after completing the vaccination schedule, and all participants were followed up from October 2021 to March 2022. The vaccines used in the study were from Pfizer-BioNTech, AstraZeneca, and Sinopharm. RESULTS: The median level of SARS-COV2 IgG was lower in HD patients than in healthy participants (p < 0.001). Regarding the type of COVID-19 vaccination, there was no statistical difference in SARS-COV2 IgG levels among HD patients. During the observation period, none of the HD patients had COVID-19. CONCLUSION: COVID-19 vaccination appeared to be protective in HD patients for 6 months and the side effects of vaccines were tolerable.

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Seaweed extracts (SWEs) are becoming integrated into crop production systems due to their multiple beneficial effects including growth promotion and induction of defence mechanisms. However, the comprehensive molecular mechanisms of these effects are yet to be elucidated. The current study investigated the transcriptomic changes induced by SWEs derived from Sargassum vulgare and Acanthophora spicifera on tomato and sweet pepper plants. Tomato and sweet pepper plants were subjected to foliar treatment with alkaline extracts prepared from the above seaweeds. Transcriptome changes in the plants were assessed 72 h after treatments using RNA sequencing. The treated plants were also analysed for defence enzyme activities, nutrient composition and phytohormonal profiles. The results showed the significant enrichment of genes associated with several growth and defence processes including photosynthesis, carbon and nitrogen metabolism, plant hormone signal transduction, plant-pathogen interaction, secondary metabolite metabolism, MAPK signalling and amino acid biosynthesis. Activities of defence enzymes were also significantly increased in SWE-treated plants. Plant nutrient profiling showed significant increases in calcium, potassium, nitrogen, sulphur, boron, copper, iron, manganese, zinc and phosphorous levels in SWE-treated plants. Furthermore, the levels of auxins, cytokinins and gibberellins were also significantly increased in the treated plants. The severity of bacterial leaf spot and early blight incidence in plants treated with SWE was significantly reduced, in addition to other effects like an increase in chlorophyll content, plant growth, and fruit yield. The results demonstrated the complex effect of S. vulgare and A. spicifera extracts on the plants' transcriptome and provided evidence of a strong role of these extracts in increasing plant growth responses while priming the plants against pathogenic attack simultaneously. The current study contributes to the understanding of the molecular mechanisms of SWEs in plants and helps their usage as a viable organic input for sustainable crop production.

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This study aimed to evaluate the effect of regrowth ages and the use of powdered molasses on nutritional characteristics of Zuri grass (Megathyrsus maximus) silages. A completely randomized design was used, in a 3 × 3 factorial scheme: three regrowth ages (65, 80, and 95 days) and three inclusion levels of powdered molasses of sugarcane (0, 20, and 40 g), with four replications. The chemical composition, fermentation parameters, in vitro digestibility, and in vitro degradation kinetics of the silages were evaluated. Greater dry matter (DM) contents were observed in silages with 95 days with 40 g of molasses. The 65 days of regrowth silages with 40 g of molasses had greater in vitro digestibility of dry matter compared to other treatments. However, lower pH values, N-NH3, DM losses, gas losses, and density were observed in silages with 95 days of regrowth with 40 g of molasses. It is recommended to cut the Zuri grass in the range of 80 to 95 days of regrowth with the addition of 40 g/kg of molasses in powders for the production of silages.

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Extracts of Ascophyllum nodosum are commonly used as commercial biostimulants in crop production. To further understand the seaweed extract-induced phenomena in plants, a transcriptomic study was conducted. RNA-seq differential gene expression analysis of tomato plants treated with a commercial A. nodosum extract formulation (Stimplex) revealed the up-regulation of 635 and down-regulation of 456 genes. Ontology enrichment analysis showed three gene categories were augmented, including biological processes, cellular components, and molecular functions. KEGG pathway analysis revealed that the extract had a strong influence on the expression of genes involved in carbon fixation, secondary metabolism, MAPK-signalling, plant hormone signal transduction, glutathione metabolism, phenylpropanoid and stilbenoid metabolism, and plant-pathogen interactions. qRT-PCR validation analysis using 15 genes established a strong correlation with the RNA sequencing results. The activities of defence enzymes were also significantly enhanced by seaweed extract treatment. Furthermore, AN-SWE treated tomato plants had significantly higher chlorophyll and growth hormone content and showed improved plant growth parameters and nutrient profiles than the control. It is postulated that seaweed extract-induced gene regulation was responsible for favourable plant responses that enabled better growth and tolerance to stress conditions. This study provides evidence at the transcriptomic level for the positive effects of foliar application of the Ascophyllum nodosum extract (Stimplex) observed in treated tomato plants.

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The use of seaweed-based bioproducts has been gaining momentum in crop production systems owing to their unique bioactive components and effects. They have phytostimulatory properties that result in increased plant growth and yield parameters in several important crop plants. They have phytoelicitor activity as their components evoke defense responses in plants that contribute to resistance to several pests, diseases, and abiotic stresses including drought, salinity, and cold. This is often linked to the upregulation of important defense-related genes and pathways in the plant system, priming the plant defenses against future attacks. They also evoke phytohormonal responses due to their specific components and interaction with plant growth regulation. Treatment by seaweed extracts and products also causes significant changes in the microbiome components of soil and plant in support of sustainable plant growth. Seaweed extracts contain a plethora of substances which are mostly organic, but trace levels of inorganic nutrient elements are also present. Fractionation of seaweed extracts into their components and their respective bioassays, however, has not yielded favorable growth effects. Only the whole seaweed extracts have been consistently proven to be very effective, which highlights the role of multiple components and their complex interactive effects on plant growth processes. Since seaweed extracts are highly organic, they are ideally suited for organic farming and environmentally sensitive crop production. They are also very compatible with other crop inputs, paving the way for an integrated management approach geared towards sustainability. The current review discusses the growth and functional effects evoked by seaweed extracts and their modes and mechanisms of action in crop plants which are responsible for elicitor and phytostimulatory activities. The review further analyses the potential value of seaweed extracts in integrated crop management systems towards sustainable crop production.

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This study evaluated the effectiveness of a commercially available Ascophyllum nodosum alkaline extract as a plant growth stimulant and defense elicitor against foliar diseases of tomato and sweet pepper caused by Xanthomonas campestris pv. vesicatoria and Alternaria solani in a tropical environment. Foliar applications of 0.5% A. nodosum extract (AN) at 10-day intervals resulted in significant (P < 0.05) increase in plant growth parameters, including plant height (40%), leaf number (50%), plant dry biomass (52%), root length (59%) and chlorophyll content (20%) compared to control. Treated plants also had a significantly higher number of flower clusters, flower numbers, fruits per cluster and total harvested fruit yield. The Ascophyllum extract significantly (P < 0.05) reduced disease incidence by the pathogens in both crops under greenhouse and field conditions. The combinatory treatment of seaweed extract and a minimum dose of contact fungicide in field trials, recorded the overall lowest disease levels (60% reduction) and highest yield (57% increase). Investigations into the mechanisms of disease suppression revealed the effects of the extract in inducing the activities of defense-related enzymes including phenylalanine ammonia lyase, peroxidase, polyphenol oxidase, chitinase and ß-1,3-glucanase, as well as the levels of total phenolic compounds. The effect on SA, JA and ET-mediated signalling defense pathways was examined by quantifying expression levels of marker genes including PR1-a, PinII and ETR-1, for the above pathways respectively. Both crop plants treated with A. nodosum extract had significantly higher expression levels of the PinII and ETR-1 marker genes than controls. This was coupled with a marked increase in gene transcripts involved in auxin (IAA), gibberellin (Ga2Ox) and cytokinin (IPT) biosynthesis, which provides possible evidence for induced growth in plants treated with AN extract. Cross-talks between growth and defense responses as a result of seaweed extract application could evidently implicate the benefits of seaweed extract usage in sustainable crop production.

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