Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Water Sci Technol ; 88(8): 1974-1981, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37906453

RESUMO

Coffee is one of the most important agricultural products in Colombia. To date, small-scale Colombian coffee growers have developed this activity with a simple infrastructure and random use of water that generates harmful by-products to the water resource mainly in the stage of separation of the mucilage. The coffee mucilage wastewater (CMW) is composed of high organic loads and its impact on water sources is due to its high load of nutrients such as nitrogen (N), phosphorus (P), and chemical oxygen demand (COD) values of over 25,000 mg/L. However, there is no consensus on what treatment can be used, especially whether it is accessible to coffee producers. Thus , the aim of this study consisted of assessing the performance of the combination of a carbon filter (CF) as pretreatment and vertical flow wetland (VFW) as a Natural-based Solution (NbS). The results show a reduction of more than 85% of COD, 96% of total solids, and UV254 close to 94%. It was remarkable that both treatments are appropriate for waters with a high concentration of solids. Finally, it can be concluded that CF + VFW is a feasible technology to treat the coffee wastewater from small communities of coffee producers.


Assuntos
Águas Residuárias , Purificação da Água , Eliminação de Resíduos Líquidos/métodos , Café , Colômbia , Áreas Alagadas , Análise da Demanda Biológica de Oxigênio , Água , Nitrogênio/análise , Purificação da Água/métodos
2.
Gac. méd. boliv ; 46(1)2023.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1448308

RESUMO

Introducción: el conocimiento y la percepción hacia los medicamentos genéricos son temas que surgen como un factor importante a explorar en los estudiantes de medicina. Objetivo: determinar las diferencias entre los estudiantes de medicina de universidades públicas y privadas sobre la percepción y el uso de las Especialidades Farmacéuticas Genéricas (EFG). Materiales y métodos: se realizó un estudio cuantitativo de tipo observacional, transversal, analítico y comparativo en un universo de 858 estudiantes matriculados durante 2019-2020 en cinco escuelas de medicina del estado mexicano de Tabasco. A través de Google Forms se recolectaron los datos de un formulario auto aplicado con base a un cuestionario previamente validado. Se emplearon estadísticas descriptivas para evaluar las percepciones de los estudiantes y pruebas no paramétricas a través de un modelo de análisis de diferencia de medias para comparar el resultado entre las universidades. Resultados: la percepción de las dimensiones de calidad (8= 12,51) y eficacia (8=6,06) muestran una postura indecisa en general. En la fiabilidad (8=6,99), los alumnos estuvieron de acuerdo. Las dimensiones de preferencia-experiencia (8=10,649) y la de accesibilidad (X=7,01), colocan a los alumnos en el grupo de indecisos. En la comparación de medias de la escala de percepción de EFG (prueba t de estudent), la universidad pública presentó una media baja (8=24,72), mientras que en el grupo de universidades privadas fue mayor (8=26,06). En cuanto al uso de EFG, la universidad pública presentó una media 8=38,22, mientras que el grupo de universidades privadas fue menor (8=36,70). Conclusiones: se requiere incluir en los contenidos curriculares de los futuros profesionales de la medicina, mayor información sobre calidad, seguridad y eficacia de las EFG, lo que contribuirá a elevar el nivel de confianza en su prescripción.


Introduction: Knowledge and perception towards generic drugs are topics that emerge as an important factor to explore in medica students. Objective: To determine the differences between medical students from public and private universities on the perception and use of Generic Pharmaceutical Specialties (GFE). Materials and methods: A quantitative observational, cross-sectional, analytica and comparative study was conducted in a universe of 858 students enrolled during 2019-2020 in five medical schools in the Mexican state of Tabasco. Through Google Forms, data were collected from a self-applied form based on a previously validated questionnaire Descriptive statistics were used to assess student perceptions, and nonparametric tests through an analysis model for difference of means to compare the result between universities. Results: The perception of the dimensions of quality (8= 12,51) and efficacy (8=6,06) shows an indecisive position in general. On reliability (8=6,99), students agreed. The dimensions of preference-experience (8=10.649) and accessibility (8=7,01), place students in the group of undecideds. In the comparison of means of the GFE perception scale (student's t test), the public university presented a low mean (8=24,72), while in the group of private universities it was higher (8=26,06). Regarding the use of GFE, the public university presented a mean 8=38,22, while the group of private universities was lower (8=36,70). Conclusions: It is necessary to include in the curricular contents of future medical professionals more information on quality, safety and efficacy of GFE, which will contribute to raising the level of confidence in their prescription.

3.
Plants (Basel) ; 11(18)2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36145795

RESUMO

In sweet cherry (Prunus avium), as in other temperate woody perennials, bud dormancy allows for survival in adverse environmental conditions during winter. During this process, environmental signals such as short days and/or low temperatures trigger internal signals that enable buds to become tolerant to the cold. The process involves tracking chilling units up to chilling the requirement fulfillment to resume growth, a transition involving transcriptional regulation, metabolic signaling, and epigenetic-related regulatory events. Massive sequencing of small RNAs was performed to identify miRNAs involved in sweet cherry dormancy by comparing their expression in field (regular seasonal) and controlled non-stop (continuous) chilling conditions. miRNAs highlighted by sequencing were validated using specific stem-loop PCR quantification, confirming expression patterns for known miRNAs such as miR156e, miR166c, miR172d, miR391, miR482c, and miR535b, as well as for newly proposed miRNAs. In silico prediction of the target genes was used to construct miRNA/target gene nodes. In particular, the involvement of the sweet cherry version for the miR156/SQUAMOSA PROMOTER-BINDING-LIKE PROTEIN genes whose expression was opposite in the two conditions suggests their involvement on dormancy regulation in sweet cherry. miRNA levels indicate that the regulation of stress-related genes and hormone synthesis modulates the expression of calcium metabolism and cell development-associated genes. Understanding the regulatory networks involved in sweet cherry dormancy, particularly in the context of miRNA involvement, represents the first step in the development of new agricultural strategies that may help overcome the increasing challenges presented by global climate change.

4.
Microorganisms ; 10(4)2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35456723

RESUMO

The B. safensis RGM 2450 and B. siamensis RGM 2529 strains were isolated from the rhizosphere of plants presenting resilience to abiotic and biotic stress conditions. To understand the implications of bacteria in resilience, a genomic and experimental analysis was carried out on their biostimulant and phytopathogenic antagonist properties. Genome analyses of both strains indicated that they have the potential to synthesize bioactive compounds such as the battery of non-ribosomal peptides, polyketides, extracellular enzymes and phytohormones. These results were consistent with the antagonistic activities of both strains against the phytopathogens Botrytis cinerea, Colletotrichum acutatum, Fusarium oxysporum and Phytophtora cinnamomi. They also showed the capacity to solubilize phosphorus, fix nitrogen and produce indole acetic acid. This was observed in tomato seedlings grown from seeds inoculated with the mixture of strains which presented significantly greater length as well as wet and dry weight in comparison with the treatments individually inoculated with each strain and the control. Accordingly, the combination of B. safensis RGM 2450 and B. siamensis RGM 2529 showed synergistic biostimulant activity. These findings contribute new knowledge of the genomic and metabolomic properties taking part in the symbiotic interactions between these strains and the plants and uphold the combined use of both strains as a biostimulant.

5.
BMC Plant Biol ; 19(1): 440, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31640557

RESUMO

BACKGROUND: In plants, host factors encoded by susceptibility (S) genes are indispensable for viral infection. Resistance is achieved through the impairment or the absence of those susceptibility factors. Many S genes have been cloned from model and crop species and a majority of them are coding for members of the eukaryotic translation initiation complex, mainly eIF4E, eIF4G and their isoforms. The aim of this study was to investigate the role of those translation initiation factors in susceptibility of stone fruit species to sharka, a viral disease due to Plum pox virus (PPV). RESULTS: For this purpose, hairpin-inducing silencing constructs based on Prunus persica orthologs were used to generate Prunus salicina (Japanese plum) 4E and 4G silenced plants by Agrobacterium tumefaciens-mediated transformation and challenged with PPV. While down-regulated eIFiso4E transgenic Japanese plums were not regenerated in our conditions, eIFiso4G11-, but not the eIFiso4G10-, silenced plants displayed durable and stable resistance to PPV. We also investigated the alteration of the si- and mi-RNA profiles in transgenic and wild-type Japanese plums upon PPV infection and confirmed that the newly generated small interfering (si) RNAs, which are derived from the engineered inverted repeat construct, are the major contributor of resistance to sharka. CONCLUSIONS: Our results indicate that S gene function of the translation initiation complex isoform is conserved in Prunus species. We discuss the possibilities of using RNAi silencing or loss-of-function mutations of the different isoforms of proteins involved in this complex to breed for resistance to sharka in fruit trees.


Assuntos
Resistência à Doença/genética , Fatores de Iniciação em Eucariotos/metabolismo , Doenças das Plantas/imunologia , Vírus Eruptivo da Ameixa/fisiologia , Prunus/genética , Fatores de Iniciação em Eucariotos/genética , Frutas/genética , Frutas/imunologia , Frutas/virologia , Doenças das Plantas/virologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Isoformas de Proteínas , Prunus/imunologia , Prunus/virologia , Interferência de RNA , RNA de Plantas/genética , RNA Interferente Pequeno/genética , Árvores
6.
Tree Physiol ; 37(12): 1739-1751, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-28541567

RESUMO

Epigenetic modifications can yield information about connections between genotype, phenotype variation and environmental conditions. Bud dormancy release in temperate perennial fruit trees depends on internal and environmental signals such as cold accumulation and photoperiod. Previous investigations have noted the participation of epigenetic mechanisms in the control of this physiological process. We examined whether epigenetic modifications were modulated in MADS-box genes, potential candidates for the regulation of bud dormancy and flowering in sweet cherry (Prunus avium L.). We identified and cloned two MADS-box genes homologous to the already-characterized dormancy regulators DORMANCY-ASSOCIATED MADS-box (DAM3 and DAM5) from Prunus persica (L.) Batsch. Bisulfite sequencing of the identified genes (PavMADS1 and PavMADS2), Methylated DNA Immunoprecipitation and small RNA deep sequencing were performed to analyze the presence of DNA methylations that could be guided by non-coding RNAs in the floral buds exposed to differential chilling hours. The results obtained reveal an increase in the level of DNA methylation and abundance of matching small interference RNAs (siRNAs) in the promoter of PavMADS1 when the chilling requirement is complete. For the first intron and 5' UTR of PavMADS1, de novo DNA methylation could be associated with the increase in the abundance of 24-nt siRNA matching the promoter area. Also, in the second large intron of PavMADS1, maintenance DNA methylation in all cytosine contexts is associated with the presence of homologous siRNAs in that zone. For PavMADS2, only maintenance methylation was present in the CG context, and no matching siRNAs were detected. Silencing of PavMADS1 and PavMADS2 coincided with an increase in Flowering Locus T expression during dormancy. In conclusion, DNA methylations and siRNAs appear to be involved in the silencing of PavMADS1 during cold accumulation and dormancy release in sweet cherry.


Assuntos
Prunus avium/genética , Prunus avium/metabolismo , Metilação de DNA/genética , Metilação de DNA/fisiologia , Epigênese Genética/genética , Epigênese Genética/fisiologia , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo
7.
J Gen Appl Microbiol ; 63(1): 11-21, 2017 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-27989999

RESUMO

The nematode Xiphinema index affects grape vines and transmits important viruses associated with fanleaf degeneration. Pseudomonas spp. are an extensive bacterial group in which important biodegradation and/or biocontrol properties can occur for several strains in the group. The aim of this study was to identify new Pseudomonas isolates with antagonist activity against X. index. Forty bacterial isolates were obtained from soil and root samples from Chilean vineyards. Thirteen new fluorescent pseudomonads were found and assessed for their antagonistic capability. The nematicide Pseudomonas protegens CHA0 was used as a control. Challenges of nematode individuals in King's B semi-solid agar Petri dishes facilitated the identification of the Pseudomonas veronii isolate R4, as determined by a 16S rRNA sequence comparison. This isolate was as effective as CHA0 as an antagonist of X. index, although it had a different lethality kinetic. Milk-induced R4 cultures exhibited protease and lipase activities in cell supernatants using both gelatin/tributyrin Petri dish assays and zymograms. Three proteins with these activities were isolated and subjected to mass spectrometry. Amino acid partial sequences enabled the identification of a 49-kDa protease similar to metalloprotease AprA and two lipases of 50 kDa and 69 kDa similar to LipA and ExoU, respectively. Electron microscopy analyses of challenged nematodes revealed degraded cuticle after R4 supernatant treatment. These results represent a new and unexplored property in this species associated with the presence of secretable lipases and protease, similar to characterized enzymes present in biocontrol pseudomonads.


Assuntos
Antibiose , Antinematódeos/farmacologia , Enzimas/farmacologia , Nematoides/efeitos dos fármacos , Proteínas/farmacologia , Pseudomonas/fisiologia , Animais , Antinematódeos/química , Antinematódeos/isolamento & purificação , Chile , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Enzimas/química , Enzimas/isolamento & purificação , Espectrometria de Massas , Microscopia Eletrônica , Peso Molecular , Nematoides/ultraestrutura , Filogenia , Raízes de Plantas/microbiologia , Proteínas/química , Proteínas/isolamento & purificação , Pseudomonas/classificação , Pseudomonas/genética , Pseudomonas/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Microbiologia do Solo , Análise de Sobrevida
8.
J Biotechnol ; 233: 200-10, 2016 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-27411902

RESUMO

The conserved mechanism of action of micro-RNAs (miRNAs) as regulators of gene expression has allowed the use of artificial miRNAs (amiRNAs) as a powerful tool for candidate gene evaluation in plants. Based on the use of a Vitis vinifera miRNA molecule (i.e., vvi-miR319e), the present work presents a new methodology for designing artificial miR319e precursors (pre-amiR319e). As a proof of concept, we silenced the green fluorescent protein (GFP) gene in transgenic Nicotiana benthamiana plants. This methodology includes a two-step PCR reaction in which overlapping long primers allow for the complete generation of pre-amiR319e-GFP molecules that are adequate for recombination into Gateway vectors with no further requirements. The seed region in amiRNA was directed against the 3'-end portion of the GFP gene. Three groups of transformed N. benthamiana plants were generated: GFP-, amiR319e-GFP-, and GFP plus miR319e-GFP-expressing vectors. A similar group of wild-type plants was included. Confocal microscopy evaluation of these groups revealed strong silencing of the GFP phenotype in the double GFP plus amiR319e-GFP group. The molecular characterization of silenced plants was achieved via modified 5'RACE of the GFP mRNA and revealed the occurrence of a partial, 3'-end GFP mRNA molecule that was generated in planta. In addition, large-scale small RNA sequencing confirmed the occurrence of the expected 21-nt miR319e-GFP species and other 22- and 24-nt species that exhibited sequence relationships with the expected amiRNA. These results highlight the possibility of using vvi-MIR319 as a template for the generation of single amiRNAs as a tool for gene silencing in plants.


Assuntos
Primers do DNA/genética , Inativação Gênica , MicroRNAs/genética , RNA de Plantas/genética , Vitis/genética , RNA de Plantas/metabolismo
9.
Transgenic Res ; 24(1): 43-60, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25011563

RESUMO

The fungi Botrytis cinerea and Erysiphe necator are responsible for gray mold and powdery mildew diseases, respectively, which are among the most devastating diseases of grapes. Two endochitinase (ech42 and ech33) genes and one N-acetyl-ß-D-hexosaminidase (nag70) gene from biocontrol agents related to Trichoderma spp. were used to develop a set of 103 genetically modified (GM) 'Thompson Seedless' lines (568 plants) that were established in open field in 2004 and evaluated for fungal tolerance starting in 2006. Statistical analyses were carried out considering transgene, explant origin, and plant response to both fungi in the field and in detached leaf assays. The results allowed for the selection of the 19 consistently most tolerant lines through two consecutive years (2007-2008 and 2008-2009 seasons). Plants from these lines were grafted onto the rootstock Harmony and established in the field in 2009 for further characterization. Transgene status was shown in most of these lines by Southern blot, real-time PCR, ELISA, and immunostrips; the most tolerant candidates expressed the ech42-nag70 double gene construct and the ech33 gene from a local Hypocrea virens isolate. B. cinerea growth assays in Petri dishes supplemented with berry juices extracted from the most tolerant individuals of the selected population was inhibited. These results demonstrate that improved fungal tolerance can be attributed to transgene expression and support the iterative molecular and physiological phenotyping in order to define selected individuals from a population of GM grapevines.


Assuntos
Quitinases/genética , Resistência à Doença/genética , Plantas Geneticamente Modificadas/genética , beta-N-Acetil-Hexosaminidases/genética , Botrytis/patogenicidade , Técnicas de Transferência de Genes , Doenças das Plantas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/microbiologia , Trichoderma/enzimologia , Trichoderma/genética , Vitis/genética , Vitis/crescimento & desenvolvimento , Vitis/microbiologia
10.
Virus Genes ; 49(2): 325-38, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24964777

RESUMO

Gene silencing and large-scale small RNA analysis can be used to develop RNA interference (RNAi)-based resistance strategies for Plum pox virus (PPV), a high impact disease of Prunus spp. In this study, a pPPViRNA hairpin-inducing vector harboring two silencing motif-rich regions of the PPV coat protein (CP) gene was evaluated in transgenic Nicotiana benthamiana (NB) plants. Wild-type NB plants infected with a chimeric PPV virus (PPV::GFP) exhibited affected leaves with mosaic chlorosis congruent to GFP fluorescence at 21 day post-inoculation; transgenic lines depicted a range of phenotypes from fully resistant to susceptible. ELISA values and GFP fluorescence intensities were used to select transgenic-resistant (TG-R) and transgenic-susceptible (TG-S) lines for further characterization of small interfering RNAs (siRNAs) by large-scale small RNA sequencing. In infected TG-S and untransformed (WT) plants, the observed siRNAs were nearly exclusively 21- and 22-nt siRNAs that targeted the whole PPV::GFP genome; 24-nt siRNAs were absent in these individuals. Challenged TG-R plants accumulated a full set of 21- to 24-nt siRNAs that were primarily associated with the selected motif-rich regions, indicating that a trans-acting siRNAs process prevented viral multiplication. BLAST analysis identified 13 common siRNA clusters targeting the CP gene. 21-nt siRNA sequences were associated with the 22-nt siRNAs and the scarce 23- and 24-nt molecules in TG-S plants and with most of the observed 22-, 23-, and 24-nt siRNAs in TG-R individuals. These results validate the use of a multi-hot spot silencing vector against PPV and elucidate the molecules by which hairpin-inducing vectors initiate RNAi in vivo.


Assuntos
Inativação Gênica , Interações Hospedeiro-Patógeno , Nicotiana/virologia , Doenças das Plantas/virologia , Vírus Eruptivo da Ameixa/crescimento & desenvolvimento , Interferência de RNA , Resistência à Doença , Perfilação da Expressão Gênica , Plantas Geneticamente Modificadas , RNA Interferente Pequeno/análise , RNA Interferente Pequeno/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA