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1.
Braz. j. biol ; 83: 00264, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1339364

RESUMO

Abstract Allium cepa L. is a commonly consumed vegetable that belongs to the Amaryllidaceae family and contains nutrients and antioxidants in ample amounts. In spite of the valuable food applications of onion bulb, its peel and outer fleshy layers are generally regarded as waste and exploration of their nutritional and therapeutic potential is still in progress with a very slow progression rate. The present study was designed with the purpose of doing a comparative analysis of the antioxidant potential of two parts of Allium cepa, i.g., bulb (edible part) and outer fleshy layers and dry peels (inedible part). Moreover, the inhibitory effect of the onion bulb and peel extracts on rat intestinal α-glucosidase and pancreatic α-amylase of porcine was also evaluated. The antioxidant potential of onion peel and bulb extracts were evaluated using 2,2-diphenyl- 1-picryl hydrazyl (DPPH), ferric-reducing antioxidant power assay (FRAP), 2,2'-azino-bis- 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assay, H2O2 radical scavenging activity and Fe2+ chelating activity. Total flavonoids and phenolic content of ethanolic extract of onion peel were significantly greater as compared to that of onion bulb. Ethanolic extract of onion peel also presented better antioxidant and free-radical scavenging activity as compared to the ethanolic extract of bulb, while the aqueous extract of bulb presented weakest antioxidative potential. Onion peel extract's α-glucosidase inhibition potential was also correlated with their phenolic and flavonoid contents. The current findings presented onion peel as a possible source of antioxidative agents and phenolic compounds that might be beneficial against development of various common chronic diseases that might have an association with oxidative stress. Besides, outer dry layers and fleshy peels of onion exhibited higher phenolic content and antioxidant activities, compared to the inner bulb. The information obtained by the present study can be useful in promoting the use of vegetable parts other than the edible mesocarp for several future food applications, rather than these being wasted.


Resumo Allium cepa pertence à família Liliaceae e é rica em nutrientes e antioxidantes. Apesar das expressivas aplicações alimentares do bulbo da cebola, sua casca e outras camadas externas são geralmente consideradas resíduos, e seu potencial nutricional e terapêutico ainda é pouco explorado. O presente estudo foi delineado com o objetivo de investigar comparativamente o potencial antioxidante de duas partes de Allium cepa, por exemplo o bulbo (parte comestível) e camadas externas e cascas secas (parte não comestível). Além disso, o efeito inibitório dos extratos do bulbo de cebola e casca sobre a α-glucosidase intestinal de ratos e α-amilase pancreática suína também foi avaliado. O potencial antioxidante dos extratos da casca de cebola e bulbo foi avaliado utilizando-se 2,2-difenil-1-picrilhidrazil (DPPH), método de poder antioxidante de redução do ferro (FRAP), método 2,2'-azino-bis-3-etilbenzotiazolina-6-ácido sulfônico (ABTS) de eliminação de radicais, atividade de eliminação de radicais H2O2 e atividade quelante do Fe2+. Os flavonoides totais e os teores fenólicos do extrato de etanol da casca de cebola foram significativamente maiores quando comparados ao do bulbo. O extrato de etanol da casca de cebola também apresentou melhor atividade antioxidante e eliminação de radicais livres quando comparado ao extrato de etanol do bulbo, enquanto o extrato aquoso de bulbo apresentou menor potencial antioxidante. O potencial de inibição da α-glicosidase dos extratos de casca de cebola correlacionou-se com seus teores fenólicos e de flavonoides. Os resultados encontrados identificaram que a casca de cebola é uma possível fonte de agentes antioxidantes e compostos fenólicos que podem ser benéficos contra o desenvolvimento de várias doenças crônicas que estão associadas ao estresse oxidativo. Além disso, as camadas externas secas e as cascas da cebola exibiram maior conteúdo fenólico e atividades antioxidantes, em comparação com o bulbo interno. As informações obtidas pelo presente estudo podem promover o uso de outras partes vegetais além do mesocarpo comestível para futuras aplicações em alimentos, ao invés de serem desperdiçadas.


Assuntos
Animais , Ratos , Cebolas , Antioxidantes , Suínos , Extratos Vegetais/farmacologia , alfa-Glucosidases , Peróxido de Hidrogênio
2.
Braz. j. biol ; 83: e240118, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278559

RESUMO

Abstract For many centuries human populations have been suffering and trying to fight with disease-bearing mosquitoes. Emerging and reemerging diseases such as Dengue, Zika, and Chikungunya affect billions of people around the world and recently has been appealing to control with chemical pesticides. Malathion (MT) is one of the main pesticides used against mosquitoes, the vectors of these diseases. This study aimed to assess cytotoxicity and mutagenicity of the malathion for the bioindicator Allium cepa L. using a multivariate and integrative approach. Moreover, an appendix table was compiled with all available literature of insecticides assessed by the Allium cepa system to support our discussion. Exposures during 48h to 0.5 mg mL-1 and 1.0 mg mL-1 MT were compared to the negative control (distilled water) and positive control (MMS solution at 10 mg L-1). The presence of chromosomal aberrations, micronuclei frequency, and mitotic index abnormalities was evaluated. Anaphase bridges were the alterations with higher incidence and presented a significantly elevated rate in the concentration of 0.5 mg mL-1, including when compared to the positive control. The integrative discriminant analysis summarizes that MT in assessed concentrations presented effects like the positive control, corroborating its potential of toxicity to DNA. Therefore, it is concluded that MT in its pure composition and in realistic concentrations used, has genotoxic potential in the biological assessment of A. cepa cells. The multivariate integrative analysis was fundamental to show a whole response of all data, providing a global view of the effect of MT on DNA.


Resumo Por muitos séculos, as populações humanas sofrem e tentam combater os mosquitos transmissores de doenças. Doenças emergentes e reemergentes como Dengue, Zika e Chikungunya afetam bilhões de pessoas em todo o mundo e, recentemente, vem apelando ao controle com pesticidas químicos. O Malation (MT) é um dos principais pesticidas usados ​​contra mosquitos, vetores dessas doenças. O objetivo deste estudo foi avaliar a citotoxicidade e a mutagenicidade do MT para o bioindicador Allium cepa L. usando uma abordagem multivariada e integrativa. Além disso, uma tabela suplementar foi compilada com toda a literatura disponível de inseticidas avaliada pelo sistema Allium cepa para apoiar nossa discussão. Exposições ao MT durante 48h a 0,5 mg mL-1 e 1,0 mg mL-1 foram comparadas a um controle negativo (água destilada) e um controle positivo (10 mg L-1 de MMS). Foram avaliadas a presença de aberrações cromossômicas, frequência de micronúcleos e anormalidades no índice mitótico. As pontes anafásicas foram as alterações com maior incidência e apresentaram uma taxa significativamente elevada na concentração de 0,5 mg mL-1, inclusive quando comparadas ao controle positivo. A análise discriminante integrativa resume que o MT nas concentrações avaliadas apresentou efeitos semelhantes ao controle positivo, corroborando seu potencial de toxicidade para o DNA. Portanto, conclui-se que o MT, em sua composição pura e nas concentrações realistas utilizadas, possui potencial genotóxico na avaliação biológica de células de A. cepa. A análise integrativa multivariada foi fundamental para mostrar uma resposta completa de todos os dados, fornecendo uma visão global do efeito da MT no DNA.


Assuntos
Humanos , Animais , Zika virus , Infecção por Zika virus , Inseticidas/toxicidade , Dano ao DNA , Aberrações Cromossômicas , Raízes de Plantas , Cebolas , Mosquitos Vetores , Malation/toxicidade , Índice Mitótico
3.
Sci Rep ; 12(1): 13044, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35915101

RESUMO

The stiffness of a plant cell in response to an applied force is determined not only by the elasticity of the cell wall but also by turgor pressure and cell geometry, which affect the tension of the cell wall. Although stiffness has been investigated using atomic force microscopy (AFM) and Young's modulus of the cell wall has occasionally been estimated using the contact-stress theory (Hertz theory), the existence of tension has made the study of stiffness more complex. Elastic shell theory has been proposed as an alternative method; however, the estimation of elasticity remains ambiguous. Here, we used finite element method simulations to verify the formula of the elastic shell theory for onion (Allium cepa) cells. We applied the formula and simulations to successfully quantify the turgor pressure and elasticity of a cell in the plane direction using the cell curvature and apparent stiffness measured by AFM. We conclude that tension resulting from turgor pressure regulates cell stiffness, which can be modified by a slight adjustment of turgor pressure in the order of 0.1 MPa. This theoretical analysis reveals a path for understanding forces inherent in plant cells.


Assuntos
Parede Celular , Células Vegetais , Parede Celular/fisiologia , Módulo de Elasticidade , Elasticidade , Microscopia de Força Atômica/métodos , Cebolas , Células Vegetais/fisiologia
4.
Biomed Res Int ; 2022: 1958939, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35924274

RESUMO

An anthraquinone textile dye, Reactive Blue 4 (RB4), poses environmental health hazards. In this study, remediation of RB4 (30-110 ppm) was carried out by hairy roots (HRs). UV-visible spectroscopy and FTIR analysis showed that the dye undergoes decolourization followed by degradation. In addition, toxicity and safety analyses of the bioremediated dye were performed on Allium cepa and zebrafish embryos, which revealed lesser toxicity of the bioremediated dye as compared to untreated dye. For Allium cepa, the highest concentration, i.e., 110 ppm of the treated dye, showed less chromosomal aberrations with a mitotic index of 8.5 ± 0.5, closer to control. Two-fold decrease in mortality of zebrafish embryos was observed at the highest treated dye concentration indicating toxicity mitigation. A higher level of lipid peroxidation (LPO) was recorded in the zebrafish embryo when exposed to untreated dye, suggesting a possible role of oxidative stress-inducing mortality of embryos. Further, the level of LPO was significantly normalized along with the other antioxidant enzymes in embryos after dye bioremediation. At lower concentrations, mitigated samples displayed similar antioxidant activity comparable to control underlining the fact that the dye at lesser concentration can be more easily degraded than the dye at higher concentration.


Assuntos
Corantes , Helianthus , Animais , Antioxidantes/metabolismo , Corantes/metabolismo , Helianthus/metabolismo , Cebolas , Raízes de Plantas/metabolismo , Têxteis , Triazinas , Peixe-Zebra/metabolismo
5.
Environ Monit Assess ; 194(9): 627, 2022 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-35916936

RESUMO

The element found at the highest amount in onion samples was sulfur, and followed by K, Ca, P, Na, and Mg in decreasing order. While K contents of white onion parts are determined between 1406.31 (outer most edible) and 1758.72 mg/kg (inner most edible), K contents of the parts of brown onions were measured between 1779.79 (head) and 2495.89 mg/kg (inner most edible). Also, K amounts of purple onions were detected between 2248.73 (shell) and 3064.64 mg/kg (middle edible). In addition, in general, the highest P, S, and K were detected in the middle edible and inner most edible parts of the edible onion samples. While the highest Ca content was localized in brown and purple onion roots, it was most localized in the shell part of white onions. In edible white and brown onions, the highest Na content was found in the inner most edible part. Fe amounts of white and brown onion samples were identified between 7.94 (head) and 20.41 mg/kg (root) to 9.56 (middle edible) and 23.67 mg/kg (head), respectively. Also, Fe contents of the parts of purple onions varied between 13.04 (shell) and 20.61 mg/kg (inner most edible). While the highest Fe and Zn are determined in the middle edible part in edible white onions, the highest Fe and Zn were determined in the outer most edible part in brown onions. In general, the most heavy metals were localized in the bark, head, and root parts of the onions. This had a positive effect on the safe edibility of onions. The heavy metal detected in the highest amount in onion samples was arsenic, followed by Cr, Al, Ni, Se, Ba, Pb, Mo, Co, and Cd in descending order. Generally, purple onion type showed maximum values. Therefore, results of the present study seen to be beneficial in the way that it allowed us to selected some varieties with nutrition value that could be interesting to introduce in gastronomy.


Assuntos
Metais Pesados , Cebolas , Monitoramento Ambiental/métodos , Metais Pesados/análise
6.
Sci Rep ; 12(1): 12570, 2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35869268

RESUMO

Roylea cinerea (D.Don) Baillon an indigenous medicinal plant of Lamiaceae family used for the treatment of several diseases. In the present study, its aqueous (leaves) extract was tested for genoprotective action against atrazine-induced chromosomal aberrations in the root tip cells of Allium cepa. Atrazine is a herbicide of triazine class commonly used to inhibit the growth of broad leaf and grassy weeds. In order to find the concentration of atrazine that exhibits maximum toxicity, its different concentrations (1, 5 and 10 µg/mL) were tested. It was observed that 10 µg/mL concentration was more toxic as it reduced the mitotic index and also increased the chromosomal aberrations. Among all the tested concentrations of aqueous (leaves) extracts (0.25. 0.5, 1.0, 1.5 and 3.0 µg/mL), the3.0 µg/mL concentration in both modes of experiments i.e. pre and post showed a significant reduction in chromosomal aberrations induced by atrazine. To understand the mechanism of protection by plant extract on atrazine-induced chromosomal abnormalities the RT-qPCR studies were conducted to observe the expression of marker genes Cyclin-dependent kinases (CDKs) (CDKA:1, CDKB2:1 and CDKD1:1. For this, the RNA was extracted from root tips treated with extract along with atrazine by TRIzol®. It was observed that aqueous extract of Roylea cinerea (D.Don) Baillon leaves upregulated the CDKs gene expression in both the modes i.e. pre and post treatments. A critical analysis of results indicated that aqueous extract ameliorated the chromosomal aberrations caused by atrazine which may be be due to the increased expression level of CDKs genes.


Assuntos
Atrazina , Lamiaceae , Atrazina/toxicidade , Aberrações Cromossômicas/induzido quimicamente , Quinases Ciclina-Dependentes/genética , Cebolas/genética , Folhas de Planta , Raízes de Plantas
7.
Molecules ; 27(14)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35889368

RESUMO

Food enrichment is commonly applied to increase the pro-health and dietary value of final products. This study aimed to evaluate how green leek powder (GL) added to semolina influenced the physicochemical, sensory, and cooking characteristics of the pasta. The pasta was prepared by partially substituting semolina with 0, 1, 2, 3, 4, and 5 g/100 g of GL. Then, the pasta samples were assessed for color, cooking properties, sensory features, mechanical properties, total phenolic content (TPC), and antioxidant activity (AA). The results indicated that GL significantly decreased the lightness and increased the yellowness of cooked pasta. The total color difference between the control pasta and enriched pasta samples ranged from 2.54 to 6.89 and 5.60 to 11.06 (for uncooked and cooked pasta, respectively). The addition of GL also caused an increase in the optimal cooking time and cooking loss. Moreover, a significant increase in stretching force was observed in cooked pasta. Sensory evaluation revealed that substitution of semolina with up to 2 g/100 g GL did not affect the smell, taste, and color of pasta. Most importantly, GL-enriched pasta was characterized by higher TPC and higher AA compared to the control samples. In summary, our results recommend partial replacement of semolina by GL (up to 3 g/100 g) in pasta production.


Assuntos
Farinha , Cebolas , Culinária/métodos , Farinha/análise , Pós , Triticum/química
8.
Molecules ; 27(14)2022 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-35889420

RESUMO

In this paper the possibility of applying natural dyes on cellulose fibres were researched with respect to the impact of cotton material pre-treatment (scouring, chemical bleaching, mercerization and mordanting), using renewable sources of natural dyes (waste as a source). As mordants, metal salts of copper, aluminium and ferrum were used, and the influence on colour change as well as on fastness properties were analysed. The natural dyes were extracted from onion peel (Allium cepa L.) and pomegranate peel (Punica granatum L.). In spectrophotometric analysis performed of the plant extracts, the onion extract has peaks at 400 and 500 nm, resulting in red-orange colourations and the pomegranate extract shows a maximum at 400 nm, i.e., in the yellow region, which is characteristic of punicalin. Results show significant influence of cotton pre-treatments on colour appearance and fastness properties, caused by pre-treatments affecting the properties and structure of the cotton itself. The positive effect of mercerization on dye absorption and bonding is confirmed. For wash and light fastness properties, more satisfactory results have been obtained for yarns dyed with pomegranate peel natural dye, and the key importance of mordants for fastness properties has been confirmed.


Assuntos
Corantes , Romã (Fruta) , Corantes/química , Gossypium , Cebolas , Extratos Vegetais/química , Têxteis
9.
Sensors (Basel) ; 22(14)2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35891126

RESUMO

The evaluation of crop health status and early disease detection are critical for implementing a fast response to a pathogen attack, managing crop infection, and minimizing the risk of disease spreading. Fusarium oxysporum f. sp. cepae, which causes fusarium basal rot disease, is considered one of the most harmful pathogens of onion and accounts for considerable crop losses annually. In this work, the capability of the PEN 3 electronic nose system to detect onion and shallot bulbs infected with F. oxysporum f. sp. cepae, to track the progression of fungal infection, and to discriminate between the varying proportions of infected onion bulbs was evaluated. To the best of our knowledge, this is a first report on successful application of an electronic nose to detect fungal infections in post-harvest onion and shallot bulbs. Sensor array responses combined with PCA provided a clear discrimination between non-infected and infected onion and shallot bulbs as well as differentiation between samples with varying proportions of infected bulbs. Classification models based on LDA, SVM, and k-NN algorithms successfully differentiate among various rates of infected bulbs in the samples with accuracy up to 96.9%. Therefore, the electronic nose was proved to be a potentially useful tool for rapid, non-destructive monitoring of the post-harvest crops.


Assuntos
Fusarium , Cebolinha Branca , Nariz Eletrônico , Cebolas/microbiologia , Doenças das Plantas/microbiologia
10.
Sci Rep ; 12(1): 12815, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35896796

RESUMO

We produced and characterised biochar made from Caribbean pine sawdust as raw material. The biochar (BC500) was used as biocompatible support to co-inoculate phosphate solubilizing bacteria (PSB) (BC500/PSB) on Allium cepa L., plants at a greenhouse scale for four months. The three biomaterials study included proximate analysis, elemental analysis, aromaticity analysis, scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), adsorption studies at different pH and PSB stability as a function of time. The results indicated that BC500 is suitable as organic support or solid matrix to maintain the viability of PSB able to solubilise P from phosphate rock (PR). The biofertilizer (BC500/PSB) allows increasing germination, seedling growth, nutrient assimilation, and growth of Allium cepa L., because PSB immobilised on BC500 promoted nutrient mobilisation, particularly P, during cultivation of Allium cepa L., at pots scale. The two treatments to evaluate the biofertilizer (BC500/PSB) showed the highest concentrations of total P with 1.25 ± 0.13 and 1.38 ± 0.14 mg bulb-1 in A. cepa L. This work presents the benefits of a new product based on bacteria naturally associated with onion and an organic material (BC500) serving as a bacterial carrier that increases the adsorption area of highly reactive nutrients, reducing their leaching or precipitation with other nutrients and fixation to the solid matrix of the soil.


Assuntos
Fosfatos , Pinus , Bactérias , Carvão Vegetal/química , Cebolas , Fosfatos/química , Solo/química
11.
An Acad Bras Cienc ; 94(2): e20200520, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35703688

RESUMO

Kavain is one of the main kavalactones of Piper methysticum (Piperaceae) with anxiolytic, analgesic, and antioxidant activities. Therefore, the aim of the study was to evaluate the cytotoxic, mutagenic, and antimutagenic potential of kavain in Allium cepa cells. Roots of A. cepa were transferred to the negative (2% acetone) and positive (10 µg/mL of Methylmethanesulfonate, MMS) controls and to the concentrations of kavain (32, 64 and 128 µg/mL) for 48 h. A total of 5,000 meristematic cells were analyzed under an optical microscope to determine the mitotic index, mean number of chromosomal alterations and percentage of damage reduction. Data were analyzed by Kruskal-Wallis test (p <0.05). All concentrations of kavain were not cytotoxic and did not show significant chromosomal changes when compared to 2% acetone. Kavain showed a cytoprotective effect in the pre (128 µg/mL) and in the post-treatment (32 and 64 µg/mL) and reduced damage against the mutagenic action of MMS in all concentrations of the pre and simultaneous and at the highest of post (128 µg/mL). Kavain promoted a significant reduction in micronuclei, nuclear buds and chromosomal losses in relation to MMS. The observed data indicate the importance of kavain for the inhibition of damage and chemoprevention.


Assuntos
Acetona , Cebolas , Acetona/farmacologia , Aberrações Cromossômicas , Meristema , Mutagênicos/toxicidade , Raízes de Plantas , Pironas/farmacologia
12.
Environ Res ; 212(Pt D): 113494, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35660404

RESUMO

Onion skin waste (OSW) is common waste in developing countries, which can cause severe environmental pollution when not properly treated. Value-added products can be chemically extracted from OSW; however, that process is not economically feasible. Alternatively, dry anaerobic digestion (DAD) of OSW is a promising approach for both energy recovery and environment protection. The main hurdles during DAD of OSW can be the hydrolysis and acidification. In batch tests, sludge digestate (SD) rich with methanogens was co-digested with different fractions of OSW for enhancing hydrolysis and raising biogas productivity. The cumulative biogas production (CBP) was 36.6 ± 0.3 mL for sole DAD of SD (100% SD) and increased up to 281.9 ± 14.1 mL for (50% SD: 50% OSW) batch. Self-delignification of OSW took place by SD addition, where the lignin removal reached 75.3 ± 10.5% for (85% SD: 15% OSW) batch. Increasing the fraction of OSW (45% SD: 55% OSW) reduced the delignification by a value of 68.8%, where initial lignin concentration was 9.48 ± 1.6% in dry weight. Lignin breaking down resulted a high fraction of phenolic compounds (345.6 ± 58.8 mg gallic acid equivalent/g dry weight) in the fermentation medium, causing CBP drop (219.0 ± 28.5 mL). The presence of elements (K, Ca, Mg, Fe, Zn, Mn, S and P) in OSW improved the enzymatic activity, facilitated phenolic compounds degradation, shifted the metabolism towards acetate fermentation pathway, and raised biogas productivity. Acidogenesis was less affected by phenolic compounds than methanogenesis, causing higher H2 contents and lower CH4 contents, at batches with high share of OSW.


Assuntos
Biocombustíveis , Cebolas , Anaerobiose , Reatores Biológicos , Lignina , Metano , Cebolas/química , Esgotos
13.
Food Res Int ; 156: 111329, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35651079

RESUMO

The effects of blue-white, green-white, yellow-white, and red-white light combinations on the nutrient composition and antioxidant capacity of pseudo-stems and leaves of 'Yuanzang' green onion were investigated using light-emitting diodes (LEDs) with precise modulation of light quality, using white light as the control. The results showed that the leaf pigment, vitamin C, soluble sugar, organic acids, free amino acids, mineral elements, and antioxidant levels were significantly higher in green onion under blue-white combined light treatment, followed by white and red-white combined light, while green-white and yellow-white combined light significantly reduced fruit quality and antioxidant capacity. In conclusion, supplementation with blue LED light was the most effective light condition to improve palatability, nutritional value, and storage resistance of green onion by enhancing various nutrients in the plants, increasing antioxidant levels, and delaying plant aging.


Assuntos
Allium , Antioxidantes , Aminoácidos , Ácido Ascórbico , Carboidratos , Minerais , Cebolas , Açúcares/metabolismo , Vitaminas
14.
BMC Med Educ ; 22(1): 504, 2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35761250

RESUMO

BACKGROUND: Teachers with a teacher-centred perspective have difficulties applying student-centred approaches in Problem Based Learning (PBL) because they are inclined to show teacher-centred behaviours. The six aspects explained in Korthagen's Onion Model (environment, behaviour, competencies, beliefs, identity, and mission) are assumed to contribute to teachers' perspectives, showing that both the environment and personal characteristics influence behaviours. For teachers to function properly in PBL, those six aspects should reflect a student-centred perspective. Previous instruments to measure teaching perspectives focused on only a few of these relevant aspects. Therefore, we developed the Student-Centred Perspective of Teachers (SCPT) questionnaire with subscales for each aspect in the Onion Model. This study aimed to provide evidence for its internal and external validity. METHODS: The SCPT was distributed in a survey to 795 teachers from 20 medical schools. For the internal validation, Confirmatory Factor Analysis was performed to analyse theoretical fit model validation, convergent validation, and discriminant validation. For the external validation, teachers' perspective scores were compared among three groups of amount of PBL training using Analysis of Variance (ANOVA) and post-hoc Least Significant Difference (LSD) tests. The p-value for all tests was set at .05. RESULTS: A total of 543 out of 795 teachers (68.3%) participated. Confirmatory Factor Analysis showed the evidence of the SCPT's internal validation with acceptable fit for the six subscales measured by 19 items and the following Composite Reliability scores: environment (.72), behaviour (.74), competencies (.63), beliefs (.55), identity (.76), and mission (.60). All items' factors loadings reached a good standard (.5 or greater). Only the environment subscale had the Average Variance Extracted (AVE) score higher than .5 and the Maximum Shared Variance score lower than the AVE score. ANOVA and Post-hoc LSD tests showed that teachers who participated in more PBL training showed significantly higher student-centred perspectives, providing evidence for external validity. CONCLUSION: The SCPT is a reliable and valid instrument to measure teaching perspectives. Identifying aspects that do not represent the adoption of a student-centred perspective may provide valuable input for faculty development in the context of PBL.


Assuntos
Dietilamida do Ácido Lisérgico , Cebolas , Humanos , Reprodutibilidade dos Testes , Estudantes , Inquéritos e Questionários
15.
Molecules ; 27(11)2022 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-35684433

RESUMO

The increasing demands of agriculture and the food market have resulted in intensive agricultural practices using synthetic fertilizers to maximize production. However, significant efforts have been made to implement more environmentally friendly procedures, such as composting, to overcome the adverse impact of these invasive practices. In the terms of this research, composting was applied to the production of two biofertilizers, using onion and mushroom by-products as raw materials respectively. The main purposes of this work were to identify the compounds that pass from the raw materials to the final products (onion-based and mushroom-based), as well as the characterization of the chemical profile of these final products following suspect and non-target screening workflows via UPLC-qToF-MS. Overall, 14 common compounds were identified in the onion and its final product, while 12 compounds were found in the mushroom and its corresponding product. These compounds belong to fatty acids, organic acids, and flavonoids, which could be beneficial to plant health. The determination of parameters, such as the pH, conductivity, organic matter, nitrogen content, and elemental analysis, were conducted for the overall characterization of the aforementioned products.


Assuntos
Compostagem , Fertilizantes , Agricultura , Fertilizantes/análise , Nitrogênio , Cebolas
16.
Food Chem ; 393: 133337, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35653990

RESUMO

Based on the mussel-inspired adhesive interface (Fe3O4-g-C3N4@PDA), a novel bionic metal-organic framework (Fe3O4-g-C3N4-PDA@MIL-101) was successfully prepared. The composite featured a high specific surface area and a multi-microchannel structure, as well as strong thermochemical stability. The structural property of Fe3O4-g-C3N4-PDA@MIL-101(Fe) was characterized, and the results indicated that Fe3O4, PDA, and MIL-101(Fe) were uniformly coated on the g-C3N4 surface. The adsorption and desorption of organophosphorus pesticides with Fe3O4-g-C3N4-PDA@MIL-101(Fe) were evaluated by batch experiments. This composite showed high adsorption efficiency and selective removal of coralox, phosalone, and chlorpyrifos. Under the optimal conditions, three organophosphorus pesticides were adsorbed from Chinese cabbage and green onion samples with Fe3O4-g-C3N4-PDA@MIL-101(Fe). The analytical method exhibited high sensitivity (LOD, 0.19-2.34 µg/L; LOQ, 0.65-7.82 µg/L), excellent practicality, and good stability, suggesting that Fe3O4-g-C3N4-PDA@MIL-101 was an ideal candidate magnetic adsorbent for the removal of organophosphorus pesticides in Chinese cabbage and green onion samples.


Assuntos
Brassica , Estruturas Metalorgânicas , Praguicidas , Poluentes Químicos da Água , Adesivos , Adsorção , China , Estruturas Metalorgânicas/química , Cebolas , Compostos Organofosforados , Praguicidas/análise , Poluentes Químicos da Água/análise
17.
Curr Biol ; 32(11): R515-R517, 2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-35671723

RESUMO

Cell wall ultrastructure has previously been assessed by thin-section transmission electron microscopy and by surface-based methods, such as atomic force microscopy. A new study uses electron tomography to image cellulose and pectin organization deep inside a thick epidermal cell wall.


Assuntos
Parede Celular , Cebolas , Biologia , Parede Celular/química , Células Epidérmicas , Microscopia de Força Atômica , Pectinas
18.
ScientificWorldJournal ; 2022: 6573754, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35514610

RESUMO

Allium species including garlic and leek exhibits a broad range of medicinal and nutritional properties. Therefore, this study investigates the physicochemical and biological activities of garlic (Allium sativum L.) and leek (A. ampeloprasum L. var. Porrum) oil extracts. The result indicated that physicochemical properties indicated that significantly higher oil yield (21.25%), ACV (2.66 mg/g), FFA (1.34%), and PV (4.10 meq/kg) and also antioxidant activities with respect to 2, 2-diphenyl-1-picrylhydrazyl, DPPH (27.60 ± 1.55%), hydrogen peroxide (12.35 ± 0.92%) free radical scavenging activities, and ascorbic acid content (25.30 ± 3.25%) were obtained for leek leaf oil extract. Stronger antibacterial activity with a maximum zone of inhibition (16.00 mm), minimum inhibitory concentration (MIC) (0.20 µg/ml), and minimum bactericidal concentration (MBC) (0.40 µg/ml) was recorded for leek oil extract against S. pyogenes. However, garlic oil has presented stronger antifungal activity with a maximum zone of inhibition (13.50 mm), MIC (0.40 µg/ml), and minimum fungicidal concentration (MFC) (0.75 µg/ml) against Candida albicans. It is concluded from the results of this investigation that oils extracts of garlic bulb and leek leaves demonstrated significant biological activities that can be used as sources for pharmaceutical and nutraceutical ingredients.


Assuntos
Allium , Produtos Biológicos , Alho , Allium/química , Antioxidantes/análise , Antioxidantes/farmacologia , Alho/química , Óleos/análise , Cebolas/química , Extratos Vegetais/análise , Extratos Vegetais/farmacologia , Folhas de Planta/química
19.
Molecules ; 27(9)2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35566028

RESUMO

Welsh onion (Allium fistulosum L.) is usually used to enhance the flavor characteristics of various foods. Volatile compounds in Welsh onions, including sulfur-containing compounds, may vary during heat process and storage. Accordingly, the changes in the volatile compounds in Welsh onions, subjected to heat and antioxidant (ascorbic acid and glutathione) treatments during storage, are investigated in the present study. The majority of sulfur-containing compounds in Welsh onions showed significant differences between the untreated Welsh onions and heated Welsh onions. During the heating of the Welsh onions, some sulfur-containing compounds, such as 2-methylthiirane, 1-(methyldisulfanyl)prop-1-ene, 1-[[(E)-prop-1-enyl]disulfanyl]propane, 1-(propyltrisulfanyl)propane, 1-[[(E)-prop-1-enyl]trisulfanyl]propane, and (methyltetrasulfanyl)methane, showed significant differences between the untreated and heated Welsh onions (p < 0.05). In addition, partial least square discriminant analysis (PLS-DA) was applied to discriminate the heated Welsh onion samples added with different antioxidants. The heated Welsh onion samples added with ascorbic acid was mainly associated with 2-phenylacetaldehyde, acetic acid, methylsulfanylmethane, prop-2-ene-1-thiol, undecan-2-one, and (2E,4E)-deca-2,4-dienal. Moreover, the key volatile compounds in the heated Welsh onion samples added with glutathione were 3-ethylthiophene, 1-(methyldisulfanyl)-1-methylsulfanylpropane, 1-methylsulfanylpentane, 2-prop-2-enylsulfanylpropane, and 1-propan-2-ylsulfanylbutane.


Assuntos
Allium , Cebolas , Antioxidantes/farmacologia , Ácido Ascórbico , Glutationa , Temperatura Alta , Propano , Enxofre
20.
Dokl Biochem Biophys ; 503(1): 85-89, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35538284

RESUMO

The effect of γ-radiation on the growth and cytogenetic endpoints of Allium cepa L. seedlings in a long period after irradiation in absorbed doses from 1.0 to 10.7 Gy were examined. The chromosome aberration rate was most sensitive to the radiation: it increased immediately after exposure at all doses. In the recovery period (up to 216 h) after irradiation, the chromosome aberration frequency naturally decreased but at the end of experiment in maximum doses remained above the control values. The impact of the initial level of chromosome aberrations on the inhibition of onion roots growth in the long terms after irradiation is discussed.


Assuntos
Cebolas , Plântula , Aberrações Cromossômicas , Análise Citogenética , Raios gama , Cebolas/genética , Cebolas/efeitos da radiação , Plântula/genética , Plântula/efeitos da radiação
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