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Castanea sativa Miller, a high-valuable crop for Mediterranean countries, is facing frequent and prolonged periods of heat and drought, severely affecting chestnut production. Aiming to tackle this problem, this study unraveled the influence of mycorrhizal association with the fungi Paxillus involutus (Batsch) on young chestnut plants' responses to combined heat (42 °C; 4 h/day) and drought (no irrigation until soil moisture reached 25%) over 21 days of stress exposure. Heat stress had no harmful effects on growth, photosynthesis, nor induced oxidative stress in either mycorrhizal (MR) or non-mycorrhizal (NMR) chestnut plants. However, drought (alone or combined) reduced the growth of NMR plants, affecting water content, leaf production, and foliar area, while also hampering net CO2 assimilation and carbon relations. The mycorrhizal association, however, mitigated the detrimental effects of both stresses, resulting in less susceptibility and fewer growth limitations in MR chestnut plants, which were capable of ensuring a proper carbon flow. Evaluation of the oxidative metabolism revealed increased lipid peroxidation and hydrogen peroxide levels in NMR plants under water scarcity, supporting their higher susceptibility to stress. Conversely, MR plants activated defense mechanisms by accumulating antioxidant metabolites (ascorbate, proline and glutathione), preventing oxidative damage, especially under the combined stress. Overall, drought was the most detrimental condition for chestnut growth, with heat exacerbating stress susceptibility. Moreover, mycorrhizal association with P. involutus substantially alleviated these effects by improving growth, water relations, photosynthesis, and activating defense mechanisms. Thus, this research highlights mycorrhization's potential to enhance C. sativa resilience against climate change, especially at early developmental stages.
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Nuts have been part of the human diet since our early ancestors, and their use goes beyond nutritional purposes, for example, as aromatic sources for dairy products. This work explores the potential of almond (Prunus dulcis (Mill.) DA Webb), hazelnut (Corylus avellana L.), and walnut (Juglans regia L.) extracts as sources of food flavouring agents, suggesting a new added-value application for lower quality or excess production fruits. The extracts were obtained by supercritical fluid extraction with carbon dioxide and characterized by: quantification of the volatile fraction by HS-SPME GC-MS; sensory perception and description; and cytotoxicity against Vero cells. All extracts revealed potential as flavouring ingredients due to terpene abundance. No significant differences were observed for the minimal sensory perception, in which the odour threshold values ranged from 8.3 × 10-4 to 6.9 × 10-3 µg·mL-1 for walnuts and almonds extracts, respectively. In contrast, the cytotoxic potential differed significantly among the extracts, and P. dulcis extract presented lower cytotoxicity. Notes as woody, fresh, and green were identified in the volatile intensifiers obtained from the P. dulcis extract. Thus, almond extract was identified as the most promising ingredient to increase the sensory value of food products, namely bread. This potential was verified by an increase in the odour perception of bread after adding 4 µL of extract to each 100 g of bread dough. The quantified eucalyptol and d-limonene terpenes - found in the P. dulcis extract - have improved the release of the pleasant and natural volatile compounds from bread crust and crumb compared to the control bread chemical and sensory profiles.
Assuntos
Corylus , Juglans , Prunus dulcis , Animais , Chlorocebus aethiops , Humanos , Nozes/química , Prunus dulcis/química , Dióxido de Carbono/análise , Aromatizantes/análise , Pão , Células Vero , Extratos Vegetais/químicaRESUMO
The potential of R. officinalis L. (RO) extracts as a source of aromas was accessed by hydrodistillation (HD) and supercritical fluid extraction using carbon dioxide (SFE-CO2), followed by a series of analysis: quantification by GC-MS, sensory perception and description, and cytotoxicity against Vero cells. The extracts shown abundancy of α-pinene, eucalyptol, S-verbenone and camphor, contributing for the green, fresh, citric, and woody as main sensory notes. The odour threshold (ODT) value (less than 3.0 × 10-3 µg·mL-1) and the cytotoxic potential (ca. 220 µgâmL-1) defined the concentration range for food application. The most promising extract was added to bread doughs and the final volatile profile was characterised by GC-MS through HS-SPME over time. Among the 34 compounds found, furfural showed an evident contribution in the bread crust aroma, which persisted over four hours of storage, contributing to a pleasant bread fragrance according to the evaluators. This study aims to represent a stepping stone for the use of natural aromas as ingredients for the development of innovative food products.
Assuntos
Ingredientes de Alimentos , Óleos Voláteis , Rosmarinus , Animais , Pão , Chlorocebus aethiops , Óleos Voláteis/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Rosmarinus/química , Sensação , Células VeroRESUMO
Humans often respond to sensory impulses provided by aromas, and current trends have generated interest in natural sources of fragrances rather than the commonly used synthetic additives. For the first time, the resulting aroma of a selected culture of Thymus mastichina L. was studied as a potential food ingredient. In this context, dried (DR) and fresh (FR) samples were submitted to carbon dioxide (CO2) supercritical extraction (SFE) and hydrodistillation (HD) methods. The extracts were characterised according to their volatile composition by GC-MS, cytotoxicity against a non-tumour cell culture, and sensory attributes (odour threshold and olfactive descriptors). The most abundant aromas were quantified, and the analysis performed by GC-MS revealed an abundance of terpenoids such as thymol chemotype, followed by the precursors α-terpinene and p-cymene. DR and FR extracts (EX) obtained from SFE-CO2 show the highest content of thymol, achieving 52.7% and 72.5% of the isolated volatile fraction. The DR essential oil (EO) contained the highest amount of terpenoids, but it was also the most cytotoxic extract. In contrast, SFE-CO2 products showed the lowest cytotoxic potential. Regarding FR-OE, it had the lowest extraction yield and composition in aroma volatiles. Additionally, all samples were described as having green, fresh and floral sensory notes, with no significant statistical differences regarding the odour detection threshold (ODT) values. Finally, FR-EX of T. mastichina obtained by SFE-CO2 presented the most promising results regarding food application.
Assuntos
Extratos Vegetais/farmacologia , Timol/análise , Thymus (Planta)/metabolismo , Antioxidantes/análise , Cromatografia com Fluido Supercrítico/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Odorantes , Óleos Voláteis/análise , Perfumes/análise , Extratos Vegetais/isolamento & purificação , Portugal , Solventes/análise , Terpenos/análiseRESUMO
OBJETIVO: Identificar as atitudes dos estudantes de enfermagem em relação à pessoa idosa. MÉTODO: Os estudantes de enfermagem inscritos no segundo ano da licenciatura foram convidados a preencher um questionário no início da unidade curricular de enfermagem geriátrica. Recorreu-se a um estudo quantitativo através da administração da Escala de Atitudes Face aos Idosos de Kogan (KAOP), validada para a população Portuguesa. RESULTADOS: A amostra foi constituída por 39 estudantes que responderam ao instrumento de coleta de dados. A atitude dos participantes em relação aos idosos apresentou um valor médio de 135,56; ligeiramente superior ao valor médio da escala (ponto médio = 119). Não foram evidenciadas relações estatisticamente significativas com nenhuma das variáveis em análise, nomeadamente o gênero, a idade, a experiência e a coabitação. CONCLUSÕES: O estudo permitiu evidenciar que a atitude dos estudantes de enfermagem em relação à pessoa idosa apresenta valores médios ligeiramente positivos, o que poderá constituir um ponto de partida para o desenvolvimento de uma intervenção para modificar a atitude dos estudantes de enfermagem em relação ao envelhecimento.
OBJECTIVE: To identify nursing students' attitudes toward older people. METHOD: Second-year undergraduate nursing students were invited to complete a questionnaire at the beginning of the geriatric nursing curricular unit. A quantitative study was conducted by administering the validated Portuguese version of Kogan's attitudes toward old people scale (KOAP). RESULTS: The sample included 39 students who answered the data collection instrument. The mean KOAP score was 135.56, which was slightly above the median value (119). No statistically significant relationships were found between any of the variables: gender, age, experience with older people, and living with older people. CONCLUSIONS: The nursing students' mean score for attitude toward older people was slightly positive, which could serve as a starting point for the development of an intervention to modify their attitudes with respect to aging.
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Humanos , Masculino , Feminino , Adulto , Estudantes de Enfermagem , Atitude do Pessoal de Saúde , Conhecimentos, Atitudes e Prática em Saúde , Educação em Enfermagem/tendências , Enfermagem Geriátrica/educação , Idoso , Saúde do Idoso , Estudos Transversais , Empatia , Relações Enfermeiro-PacienteRESUMO
Estimating the area of seabed surfaces from pictures or videos is an important problem in seafloor surveys. This task is complex to achieve with moving platforms such as submersibles, towed or remotely operated vehicles (ROV), where the recording camera is typically not static and provides an oblique view of the seafloor. A new method for obtaining seabed surface area estimates is presented here, using the classical set up of two laser devices fixed to the ROV frame projecting two parallel lines over the seabed. By combining lengths measured directly from the image containing the laser lines, the area of seabed surfaces is estimated, as well as the camera's distance to the seabed, pan and tilt angles. The only parameters required are the distance between the parallel laser lines and the camera's horizontal and vertical angles of view. The method was validated with a controlled in situ experiment using a deep-sea ROV, yielding an area estimate error of 1.5%. Further applications and generalizations of the method are discussed, with emphasis on deep-sea applications.
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Processamento de Imagem Assistida por Computador , Água do Mar , Imageamento Tridimensional , Lasers , Fenômenos Ópticos , Fotografação/instrumentação , Reprodutibilidade dos Testes , Propriedades de Superfície , IncertezaRESUMO
BACKGROUND: To obtain robust epidemiological information regarding tuberculosis (TB) in wildlife species, appropriate diagnostic methods need to be used. Wild boar (Sus scrofa) recently emerged as a major maintenance host for TB in some European countries. Nevertheless, no data is available to evaluate TB post-mortem diagnostic methods in hunter-harvested wild boar. METHODOLOGY/PRINCIPAL FINDINGS: Six different diagnostic methods for TB were evaluated in parallel in 167 hunter-harvested wild boar. Compared to bacteriological culture, estimates of sensitivity of histopathology was 77.8%, gross pathology 72.2%, PCR for the MPB70 gene 66.7%, detection of acid-fast bacilli (AFB) in tissue contact smears 55.6% and in histopathology slides 16.7% (estimated specificity was 96.7%, 100%, 100%, 94.4% and 100%, respectively). Combining gross pathology with stained smears in parallel increased estimated sensitivity to 94.4% (94.4% specificity). Four probable bacteriological culture false-negative animals were identified by Discriminant Function Analysis. Recalculating the parameters considering these animals as infected generated estimated values for sensitivity of bacteriology and histopathology of 81.8%, gross pathology 72.7%, PCR for the MPB70 gene 63.6%, detection of AFB in tissue contact smears 54.5% and in histopathology slides 13.6% (estimated specificity was 100% for gross pathology, PCR, bacteriology and detection of AFB in histopathology slides, 96.7% for histopathology and 94.4% for stained smears). CONCLUSIONS/SIGNIFICANCE: These results show that surveys for TB in wild boar based exclusively on gross pathology considerably underestimate prevalence, while combination of tests in parallel much improves sensitivity and negative predictive values. This finding should thus be considered when planning future surveys and game meat inspection schemes. Although bacteriological culture is the reference test for TB diagnosis, it can generate false-negative results and this should be considered when interpreting data.