Annealing Temperature Effect on Structural and Luminescence Spectroscopy of Y2SiO5:Ce3+ Nanomaterial Synthesized by Sol–Gel Method

Ce3+ - doped Y2SiO5 nanophosphors were successfully produced by Sol-Gel process. To study the influence of the temperature on the structure and the luminescence of Y2SiO5:Ce3+, we annealed the xerogels at the temperatures 800, 900, 950, 1000, 1050 and 1250 °C. The X-ray diffraction technique (XRD), field emission scanning electron microscopy (FEG-SEM), Fourier transform infrared spectroscopy (FTIR) and steady photoluminescence were used to characterize the samples. The crystallite size keeps the same value in the temperature range 950-1050 °C. The room temperature steady photoluminescence emission and excitation of Ce3+ in X1-Y2SiO5:Ce3+ nanomaterial with increasing temperature were measured and investigated. At the crystallization temperature of 1250 °C, we have a new structure X2- Y2SiO5:Ce3+ with grain sizes larger than the X1-Y2SiO5:Ce3+ and also intense violet-blue emission

Food preservative extracts from pumpkin by-products

Pumpkin is a vegetable widely consumed around the world, popularly known for its nutritional and pharmacological properties. Some reports in the literature reveal the rich profile of nutrients and bioactive compounds of pumpkin varieties [1,2]. However, the seeds, peels, and fibers resulting from pumpkin processing are still poorly explored by food industry. Considering the alarming scenario of losses and waste during all the food supply chain worldwide [3] and seeking to promote a more sustainable food system, the present study purposed to investigate the by-products of different varieties of pumpkin as a source of extracts with preservative capacity for food application. For that purpose, hydroethanolic extracts from the varieties “Butternut squash”, “Common pumpkin”, and “Kabocha squash” from Portugal, and “Butternut squash”, “Common pumpkin”, and “Musquée de provence” from Algeria, were evaluated in terms of their bioactivities, more specifically the antioxidant, antimicrobial, and cytotoxic capacities. All the samples presented great antioxidant capacity through two based-cell assays, namely the lipid peroxidation inhibition capacity (TBARS) and the anti-hemolytic activity (OxHLIA). Interestingly, the seeds of the common pumpkin from Algeria did not present antihemolytic properties, despite showing the strongest lipid peroxidation inhibition capacity. In fact, the seeds stood out for all the pumpkin varieties in the TBARS assay, while in the OxHLIA assay, the results were quite similar between the type of bioresidues and between the varieties. Moreover, the samples from Portugal showed greater antioxidant capacity than the Algerian ones. Regarding cytotoxicity, the effect of inhibiting non-tumor cell growth was not observed, even at the highest tested concentration of 400 μg/mL. This first validation is of great importance to prevent food safety issues. These preliminary results are the basis for future studies aiming at the valorization of these bioresidues from food industry as a great source of preservative compounds toward the replacement of synthetic additives with natural alternatives allied to health benefits, as also the promotion of a circular economyThe authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); national funding by FCT, P.I., through the institutional scientific employment program-contract for C. Pereira and L. Barros contracts and A.K. Molina and M.G. Leichtweis PhD grants (2020.06231.BD and 2020.06706.BD, respectively). To FCT, P.I., within the scope of the Project PRIMA Section 2 - Multi-topic 2019: PulpIng (PRIMA/0007/2019).info:eu-repo/semantics/publishedVersio

Biological activity of pumpkin byproducts: antimicrobial and antioxidant properties

Pumpkin fruits are widely appreciated and consumed worldwide. In addition to their balanced nutritional profile, pumpkin species also present valuable bioactive compounds that confer biological and pharmacological properties to them. However, the seeds, peels, and fibrous strands resulting from pumpkin processing are still poorly explored by the food industry. The current study used those fruit components from the genotypes of pumpkin that are economically significant in Portugal and Algeria to produce bioactive extracts. In order to support their usage as preservatives, their phenolic content (HPLC-DAD-ESI/MS) and antioxidant (OxHLIA and TBARS) and antimicrobial properties (against eight bacterial and two fungal strains) were assessed. In terms of phenolic profile, the peel of the Portuguese ‘Common Pumpkin’ showed the most diversified profile and also the highest concentration of total phenolic compounds, with considerable concentrations of (-)-epicatechin. Regarding the antioxidant capacity, the seeds of ‘Butternut Squash’ from both countries stood out, while the fibrous strands of Portuguese ‘Butternut Squash’ and the seeds of Algerian ‘Gold Nugget Pumpkin’ revealed the strongest antimicrobial activity. The bioactive compounds identified in the pumpkin byproducts may validate their enormous potential as a source of bio-based preservatives that may enhance consumers’ health and promote a circular economy.info:eu-repo/semantics/publishedVersio

Heavy metal soil contamination detection using combined geochemistry and field spectroradiometry in the United Kingdom

Technological advances in hyperspectral remote sensing have been widely applied in heavy metal soil contamination studies, as they are able to provide assessments in a rapid and cost-effective way. The present work investigates the potential role of combining field and laboratory spectroradiometry with geochemical data of lead (Pb), zinc (Zn), copper (Cu) and cadmium (Cd) in quantifying and modelling heavy metal soil contamination (HMSC) for a floodplain site located in Wales, United Kingdom. The study objectives were to: (i) collect field- and lab-based spectra from contaminated soils by using ASD FieldSpec® 3, where the spectrum varies between 350 and 2500 nm; (ii) build field- and lab-based spectral libraries; (iii) conduct geochemical analyses of Pb, Zn, Cu and Cd using atomic absorption spectrometer; (iv) identify the specific spectral regions associated to the modelling of HMSC; and (v) develop and validate heavy metal prediction models (HMPM) for the aforementioned contaminants, by considering their spectral features and concentrations in the soil. Herein, the field- and lab-based spectral features derived from 85 soil samples were used successfully to develop two spectral libraries, which along with the concentrations of Pb, Zn, Cu and Cd were combined to build eight HMPMs using stepwise multiple linear regression. The results showed, for the first time, the feasibility to predict HMSC in a highly contaminated floodplain site by combining soil geochemistry analyses and field spectroradiometry. The generated models help for mapping heavy metal concentrations over a huge area by using space-borne hyperspectral sensors. The results further demonstrated the feasibility of combining geochemistry analyses with filed spectroradiometric data to generate models that can predict heavy metal concentrations

Valorização de cascas, sementes e fibras de abóbora no desenvolvimento de extratos bioativos para aplicação alimentar

Na Europa, quase metade da produção de frutas e hortaliças é perdida ou desperdiçada, principalmente nas etapas de processamento, através da geração de grandes quantidades de cascas.info:eu-repo/semantics/publishedVersio

Cerebellar Volume and Disease Staging in Parkinson's Disease: An ENIGMA-PD Study.

peer reviewed[en] BACKGROUND: Increasing evidence points to a pathophysiological role for the cerebellum in Parkinson's disease (PD). However, regional cerebellar changes associated with motor and non-motor functioning remain to be elucidated. OBJECTIVE: To quantify cross-sectional regional cerebellar lobule volumes using three dimensional T1-weighted anatomical brain magnetic resonance imaging from the global ENIGMA-PD working group. METHODS: Cerebellar parcellation was performed using a deep learning-based approach from 2487 people with PD and 1212 age and sex-matched controls across 22 sites. Linear mixed effects models compared total and regional cerebellar volume in people with PD at each Hoehn and Yahr (HY) disease stage, to an age- and sex- matched control group. Associations with motor symptom severity and Montreal Cognitive Assessment scores were investigated. RESULTS: Overall, people with PD had a regionally smaller posterior lobe (dmax  = -0.15). HY stage-specific analyses revealed a larger anterior lobule V bilaterally (dmax  = 0.28) in people with PD in HY stage 1 compared to controls. In contrast, smaller bilateral lobule VII volume in the posterior lobe was observed in HY stages 3, 4, and 5 (dmax  = -0.76), which was incrementally lower with higher disease stage. Within PD, cognitively impaired individuals had lower total cerebellar volume compared to cognitively normal individuals (d = -0.17). CONCLUSIONS: We provide evidence of a dissociation between anterior "motor" lobe and posterior "non-motor" lobe cerebellar regions in PD. Whereas less severe stages of the disease are associated with larger motor lobe regions, more severe stages of the disease are marked by smaller non-motor regions

Efficient synthesis of zinc-containing mesoporous silicas by microwave irradiation method and their high activities in acetylation of 1,2-dimethoxybenzene with acetic anhydride

A series of acid zinc-containing mesoporous materials have been synthesized by microwave irradiation method with different Si/Zn ratios (Si/Zn = 100, 65, 15) and characterized by several spectroscopic techniques such as: N2 physical adsorption, ICP, XRD, TEM, FT-IR and a temperature-programmed-desorption (TPD) of pyridine. The liquid phase of acetylation of 1,2-dimethoxybenzene with acetic anhydride has been investigated over this series of catalysts. In fact, the catalyst Zn-JLU-15 (15) showed bigger performance in the acid-catalyzed acetylation of 1,2-dimethoxybenzene employing acetic anhydride as an acylating agent. Furthermore, the kinetics of the acetylation of 1,2-dimethoxybenzene over these catalysts have also been investigated

Catalytic properties of Thallium-containing mesoporous silicas

The benzylation of benzene by benzyl chloride over a series of Thallium-containing mesoporous silicas with different Tl contents has been investigated. These materials (Tl-HMS-n) have been characterized by chemical analysis, N2 adsorption/desorption isotherm and X-ray diffraction (XRD). The mesoporous Thallium-containing materials showed both high activity and high selectivity for the benzylation of benzene. More interesting is the observation that these catalysts are always active and selective for large molecules like naphthenic compounds such as methoxynaphthalene

Catalytic behavior of gallium-containing mesoporous silicas

The vapor phase tert-butylation of anisole with tert-butanol reaction has been inspected over a series of Ga-FSM-16 with different Si/Ga ratios = 75, 35, 5 synthesized by intercalating kanemite using cetyltrimethylammonium bromide (CTMABr) and gallium nitrate. The resulting samples were characterized by means of inductively coupled plasma (ICP) technique, BET, BJH, XRD and a temperature–programed–desorption (TPD) of pyridine. In addition, the influence of molar ratio, influence of temperature, weight hourly space velocity (WHSV) and time on stream on the selectivity of products was investigated and the results are discussed