334 research outputs found
Membrane processing of grape must for control of the alcohol content in fermented beverages
The great demand of beverages, both alcohol-free and with low alcohol content, is a great challenge for the production of beverages with controlled alcohol content through the use
of sustainable enological practices. The present work addresses this challenge with the processing of grape must by reverse osmosis (RO) for must reconstitution with different sugar
contents prior to the alcoholic fermentation. The original must came from grapes grown in Quinta do Quinto, in Santarém, collected after destemming and mechanic crushing, and
preserved in a refrigerated chamber at -1.6 °C until processing by RO. The RO processing was carried out in Escola Superior Agrária de Santarém, with a pilot plant equipped with RO
spiral wound modules, M38RO, from Alfa Laval, Denmark. The total membrane permeation area is 15 m2. The work pressure was 55 bar. The original must had 23.7 oBrix, a density
of 1108 g.L-1, 15.2% (v/v) of probable alcohol, and a conductivity of 2.01 mS.cm-1. The must reconstitution was carried out, by mixing the concentrated grape must with the vegetal
water produced by RO (permeate) to obtain beverages with a nominal alcohol content of 5%, 7%, 10% and 13% (v/v). The fermentation average temperature was between 18.2 and
19.7 °C, and the final density rounded about 993 g.cm-3. The beverages were analysed by different parameters, including total polyphenols, total anthocyanins, colour intensity and
hue, the coordinates CIELab, alcohol content, total acidity, volatile acidity, pH, free SO2 and total SO2. The attributes of the beverage, corresponding to the visual appearance, aroma
and taste senses, as well as the overall judgment were evaluated by the tasters. The proposed method can produce beverages with controlled low alcohol content. The decrease of the
alcohol content led to lower content of polyphenols compounds which influenced the sensory evaluation.info:eu-repo/semantics/publishedVersio
Gender-Specific Effects on the Cardiorespiratory System and Neurotoxicity of Intermittent and Permanent Low-Level Lead Exposures
\ua9 2024 by the authors. Lead exposure is a significant health concern, ranking among the top 10 most harmful substances for humans. There are no safe levels of lead exposure, and it affects multiple body systems, especially the cardiovascular and neurological systems, leading to problems such as hypertension, heart disease, cognitive deficits, and developmental delays, particularly in children. Gender differences are a crucial factor, with women’s reproductive systems being especially vulnerable, resulting in fertility issues, pregnancy complications, miscarriages, and premature births. The globalization of lead exposure presents new challenges in managing this issue. Therefore, understanding the gender-specific implications is essential for developing effective treatments and public health strategies to mitigate the impact of lead-related health problems. This study examined the effects of intermittent and permanent lead exposure on both male and female animals, assessing behaviours like anxiety, locomotor activity, and long-term memory, as well as molecular changes related to astrogliosis. Additionally, physiological and autonomic evaluations were performed, focusing on baro- and chemoreceptor reflexes. The study’s findings revealed that permanent lead exposure has more severe health consequences, including hypertension, anxiety, and reactive astrogliosis, affecting both genders. However, males exhibit greater cognitive, behavioural, and respiratory changes, while females are more susceptible to chemoreflex hypersensitivity. In contrast, intermittent lead exposure leads to hypertension and reactive astrogliosis in both genders. Still, females are more vulnerable to cognitive impairment, increased respiratory frequency, and chemoreflex hypersensitivity, while males show more reactive astrocytes in the hippocampus. Overall, this research emphasizes the importance of not only investigating different types of lead exposure but also considering gender differences in toxicity when addressing this public health concern
The historical ecological background of West Nile virus in Portugal indicates One Health opportunities
West Nile (WNV) is a zoonotic arbovirus with an expanding geographical range and epidemic activity in Europe. Not having yet experienced a human-associated epidemic, Portugal remains an outlier in the Mediterranean basin. In this study, we apply ecological niche modelling informed by WNV historical evidence and a multitude of environmental variables from across Portugal. We identify that ecological backgrounds compatible with WNV historical circulation are mostly restricted to the south, characterized by a warmer and drier climate, high avian diversity, specific avian species and land types. We estimate WNV ecological suitability across the country, identifying overlaps with the distributions of the three relevant hosts (humans, birds, equines) for public and animal health. From this, we propose a category-based spatial framework providing first of a kind valuable insights for WNV surveillance in Portugal under the One Health nexus. We forecast that near future climate trends alone will contribute to pushing adequate WNV ecological suitability northwards, towards regions with higher human density. This unique perspective on the past, present and future ecology of WNV addresses existing national knowledge gaps, enhances our understanding of the evolving emergence of WNV, and offers opportunities to prepare and respond to the first human-associated epidemic in Portugal.info:eu-repo/semantics/publishedVersio
Nanofiltration of Cork Wastewaters and Their Possible Use in Leather Industry as Tanning Agents
Cork processing wastewater is a very complex mixture of vegetal extracts and has, among other natural compounds, a very high content of phenolic/tannic colloidal matter that is responsible for severe environmental problems. In the present work, the concentration of this wastewater by nanofiltration was investigated with the aim of producing a cork tannin concentrate to be utilized in tanning. Permeation results showed that the permeate fluxes are controlled by both osmotic pressure and fouling/gel layer phenomena, leading to a rapid decrease of permeate fluxes with the concentration factor. The rejection coefficients to organic matter were higher than 95%, indicating that nanofiltration has a very good ability to concentrate the tannins and produce a permeate stream depleted from organic matter. The cork tannin concentrate obtained by nanofiltration and evaporation had total solids concentration of 34.8 g/l. The skins tanned by this concentrate were effectively converted to leather with a shrinking temperature of 7 degrees C
Tilt Training Increases Vasoconstrictor Reserve in Patients with Neurocardiogenic Syncope
A sÃncope neurocardiogénica (SNc) é uma entidade clÃnica comum, resultante de uma
resposta autonómica reflexa excessiva durante o stress ortostático. As diferentes opções terapêuticas são controversas e de eficácia limitada. O treino de ortostatismo (TTr) tem-se mostrado uma alternativa prometedora no tratamento destes doentes (D). No entanto, permanece por esclarecer o seu mecanismo de acção e o impacto clÃnico numa população com SNc recorrente.
Objectivo: Caracterizar a resposta hemodinâmica e autonómica durante um programa de TTr em doentes com SNc refratária às medidas convencionais.
População e métodos: Foram estudados 28D (50% do sexo masculino, 41±14 anos), sem evidência de cardiopatia, com SNc documentada em teste de ortostatismo passivo. O TTr incluiu 9 sessões hospitalares (3x/semana, 30 minutos) com monitorizac¸ão contÃnua de pressão arterial
e frequência cardÃaca (60â—¦ - 6 sessões - 70â—¦ - 3 sessões), complementadas com treino diário no domicÃlio e elevação da cabeceira a 10â—¦ durante o sono. O volume sistólico, o débito cardÃaco, a resistência vascular periférica, a sensibilidade do barorreflexo e a variabilidade da frequência cardÃaca foram calculados. Todos os doentes foram reavaliados no fim do 1.â—¦ mês e no final de
cada 6 meses num perÃodo máximo de 36 meses (follow-up 24±12 meses).
Resultados: Ao longo das sessões de TTr verificou-se um aumento significativo e consistente da resistência total periférica (1485±225 vs. 1591±187 dyne*s/cm−5, p < 0,05) associado a uma diminuição do seu desvio-padrão (206±60 vs. 150±42, p < 0,05). Durante o perÃodo de follow-up, houve recorrência de sÃncope em 5D (19%), com redução significativa do número de
sÃncopes (4,0±3,2/D nos 12 meses pre-TTr vs. 1,4±0,8/D pos-TTr, p < 0,05). Conclusão: Em doentes com SNc refratária, o TTr mostrou ser uma opção terapêutica eficaz, com benefÃcio a longo prazo. A melhor tolerância ao ortostatismo parece resultar do aumento
da reserva vasoconstritora e da sua menor variabilidade
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