902 research outputs found

    Interaction between vasotocin and gonadal hormones in the regulation of reproductive behavior in a cichlid fish

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    Vasotocin (VT) has been associated with the regulation of diferent aspects of social behavior (e.g., mating and aggression). Given the fact that androgens are also known to regulate reproductive behavior, we hypothesized that VT and androgens could be interacting, rather than acting independently, in the regulation of reproductive behavior. In the present study, we aimed to understand the efect of VT and its interaction with gonadal hormones (putatively androgens) on diferent aspects of reproductive behavior of a polygynous and territorial cichlid fsh, the Mozambique tilapia (Oreochromis mossambicus). Using a within-subject design, we treated territorial males, that were previously castrated or sham-operated, with diferent dosages of VT as well as with a V1A receptor antagonist (Manning compound) and subsequently analyzed their behavior towards females and towards an intruder male. Our results showed that VT afected the behavior of territorial males towards females but not towards males. Specifcally, VT-treated males interacted less with females (i.e., spent less time touching the transparent partition that allowed visual contact with females) and were less aggressive towards females than salinetreated males. Moreover, in sham-operated males, blocking V1A receptors increased the frequency of bites towards females in comparison to saline-treated males, but not in castrated males. This result suggests that VT down-regulates aggressiveness towards females through the action of V1A receptors in the gonads (putatively decreasing androgen secretion), and that androgens up-regulate this behavior. In summary, our results suggest that VT may modulate social behavior, through an interaction with gonadal hormones.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

    Evaluation of the Efficacy of CPP-ACP Remineralizing Mousse in MIH White and Yellow Opacities—In Vitro Vickers Microhardness Analysis

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    Funding Information: This research was funded by Fundação para a Ciência e Tecnologia (FCT) (Portugal) by the research center grant UID/FIS/04559/2021 to LIBPhys from the FCT/MCTES/PIDDAC, Portugal. This research was also funded by Cuf, SA by Inês Cardoso-Martins PhD scholarship. Publisher Copyright: © 2022 by the authors.Remineralization of tooth enamel can be partially achieved by the application of a casein phosphopeptides and amorphous phosphate (CPP-ACP) complex. However, evidence to support its effectiveness in Molar-incisor-hypomineralization (MIH)-affected teeth is scarce. The study’s aim is to evaluate the efficacy of CPP-ACP mousse in remineralizing MIH-affected enamel using a Vickers microhardness test. Two groups of enamel opacities of hypomineralized permanent teeth, white (group A) and yellow (group B) lesions (n = 14), went through a 28-day treatment protocol with GC Tooth Mousse. Before and after treatment, microhardness was measured in three different areas of each tooth (hypomineralized, transition, and outside the hypomineralized area). Data were analyzed using parametric and non-parametric tests with a significance of p < 0.05. The mean microhardness values increased in the hypomineralized and transition areas in both groups after the treatment protocol (in group A, 105.38 ± 11.70 to 158.26 ± 37.34; 123.04 ± 22.84 to 156.33 ± 35.70; in group B, 108.63 ± 14.66 to 143.06 ± 22.81; 132.55 ± 20.66 to 146.00 ± 12.88) and the differences pre/post-treatment were statistically significant within each group (p < 0.001 for both groups). Between groups, there was a statistically significant difference in the same areas (hypomineralized: p = 0.003; transition: p = 0.008) with a higher improvement in enamel hardness in group A. Topical application of CPP-ACP showed an increase in the physical strength of the hypomineralized and transition areas of MIH-affected enamel, likely due to an increase in mineral content.publishersversionpublishe

    Effect of drying technology in Saccharomyces cerevisiae mannans: structural, physicochemical, and functional properties

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    Mannans are polysaccharides whose physicochemical and biological properties render them commercialization in several products. Since these properties are strongly dependent on production conditions, the present study aims to assess the impact of different drying technologies – freeze (FDM) and spray drying (SDM) – on the structural, physicochemical, and biological properties of mannans from Saccharomyces cerevisiae. Structural analysis was assessed by FT-IR, PXRD and SEM, whereas physicochemical properties were evaluated based on sugars, protein, ash and water contents, solubility, and molecular weight distribution. Thermal behaviour was analysed by DSC, and antioxidant activity by DPPH and ABTS assays. The parameters which revealed major differences, in terms of structural and physicochemical properties regarded morphology (SEM), physical appearance (colour), moisture (3.6 ± 0.1 % and 11.9 ± 0.6% for FDM and SDM, respectively) and solubility (1 mg/mL for FDM and 25 mg/mL for SDM). Nevertheless, these differences were not translated into the antioxidant capacity.info:eu-repo/semantics/publishedVersio

    A step for the valorization of spent yeast through production of iron–peptide complexes — a process optimization study

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    Given the importance of iron in human nutrition and the significance of waste and by-product valorisation in a circular economy environment, we investigated the effects of protein and iron concentration on the production yield of iron–peptide complexes from spent Saccharomyces cerevisiae. For this purpose, different amounts of protein and iron were used in the complexation process. The results have shown that higher concentrations, although permitting a faster and larger scale process, provide a significantly lower complexation yield, which deems the process less feasible. This is corroborated by fluorescence analysis, which shows a lower degree of complexation with higher protein concentration. In addition, varying the concentration of iron does not change the quality of formed complexes, as evidenced by Fourier transform infrared spectroscopy (FT-IR) analysis. The morphology of all samples was also evaluated using scanning electron microscopy (SEM). Therefore, further studies are needed to optimize the process and to evaluate the best conditions for an economically sound valorization process for iron–peptide complexes. Nonetheless, current results in the development of a new process for the valorisation of spent yeast, in the form of iron-peptide complexes, look promising.info:eu-repo/semantics/publishedVersio

    Effect of mannan oligosaccharides extracts in uropathogenic escherichia coli adhesion in human bladder cells

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    Urinary tract infections (UTIs) are a common public health problem, mainly caused by uropathogenic Escherichia coli (UPEC). Patients with chronic UTIs are usually treated with long-acting prophylactic antibiotics, which promotes the development of antibiotic-resistant UPEC strains and may complicate their long-term management. D-mannose and extracts rich in D-mannose such as mannan oligosaccharides (MOS; D-mannose oligomers) are promising alternatives to antibiotic prophylaxis due to their ability to inhibit bacterial adhesion to urothelial cells and, therefore, infection. This highlights the therapeutic potential and commercial value of using them as health supplements. Studies on the effect of MOS in UTIs are, however, scarce. Aiming to evaluate the potential benefits of using MOS extracts in UTIs prophylaxis, their ability to inhibit the adhesion of UPEC to urothelial cells and its mechanism of action were assessed. Additionally, the expression levels of the pro-inflammatory marker interleukin 6 (IL-6) were also evaluated. After characterizing their cytotoxic profiles, the preliminary results indicated that MOS extracts have potential to be used for the handling of UTIs and demonstrated that the mechanism through which they inhibit bacterial adhesion is through the competitive inhibition of FimH adhesins through the action of mannose, validated by a bacterial growth impact assessment.info:eu-repo/semantics/publishedVersio

    Lipidomic Assessment of Plasma and Placenta of Women with Early-Onset Preeclampsia

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    Introduction: Adipose tissue is responsible for triggering chronic systemic inflammatory response and these changes may be involved in the pathophysiology of preeclampsia. Objective: To characterize the lipid profile in the placenta and plasma of patients with preeclampsia. Methodology Samples were collected from placenta and plasma of 10 pregnant women with preeclampsia and 10 controls. Lipids were extracted using the Bligh–Dyer protocol and were analysed by MALDI TOF-TOF mass spectrometry. Results: Approximately 200 lipid signals were quantified. The most prevalent lipid present in plasma of patients with preeclampsia was the main class Glycerophosphoserines-GP03 (PS) representing 52.30% of the total lipid composition, followed by the main classes Glycerophosphoethanolamines-GP02 (PEt), Glycerophosphocholines-GP01 (PC) and Flavanoids-PK12 (FLV), with 24.03%, 9.47% and 8.39% respectively. When compared to the control group, plasma samples of patients with preeclampsia showed an increase of PS (p<0.0001), PC (p<0.0001) and FLV (p<0.0001). Placental analysis of patients with preeclampsia, revealed the PS as the most prevalent lipid representing 56.28%, followed by the main class Macrolides/polyketides-PK04 with 32.77%, both with increased levels when compared with patients control group, PS (p<0.0001) and PK04 (p<0.0001). Conclusion: Lipids found in placenta and plasma from patients with preeclampsia differ from those of pregnant women in the control group. Further studies are needed to clarify if these changes are specific and a cause or consequence of preeclampsia

    Evidencia de validad de la versión portuguesa del Índice de Reactividad Interpersonal en Parejas

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    The main objective of this study was to translate and adapt the Interpersonal Reactivity Index for Couples (IRIC) to Portuguese, and analyze the psychometric properties of the Portuguese version. This instrument that assesses empathy in couples, resulted from the adaptation of one of the most widely used empathy scales - Davis's Interpersonal Reactivity Index - for the context of intimate relationships. The IRIC assesses dimensions of cognitive (perspective taking) and emotional (empathic concern) empathy, both essential for stable and satisfactory marital relationships. The original scale was translated to Portuguese and administered to 148 participants involved in an intimate relationship with a minimum duration of one year. Most of the participants were women, with a mean age of 27 years old. Our results revealed the Portuguese version has a factorial structure similar to the original version, adequate internal consistency values (Cronbach's α=.82), and good external validity with a scale of dyadic adjustment.Este estudo teve como principal objetivo traduzir e adaptar para língua portuguesa o Índice de Reatividade Interpessoal para Casais (IRIC), analisando as propriedades psicométricas da versão portuguesa. Esse é um instrumento de avaliação da empatia em casais, que resultou da adaptação de uma das mais usadas escalas de empatia, o Índice de Reatividade Interpessoal de Davis, para o contexto das relações íntimas. O IRIC avalia dimensões de empatia cognitiva (tomada de perspetiva) e emocional (preocupação empática), importantes para a estabilidade e satisfação das relações conjugais. A escala original foi traduzida para português e administrada a 148 sujeitos que estavam numa relação amorosa há pelo menos um ano. A maioria dos sujeitos eram mulheres com uma média de idades de 27 anos. Os resultados revelam uma estrutura fatorial semelhante à escala original, valores adequados de consistência interna (alfa de Cronbach=0,82) e bons níveis de validade externa com uma escala de ajustamento diádico.El principal objetivo de este estudio fue traducir y adaptar a la lengua portuguesa el Índice de Reactividad Interpersonal para Parejas (IRIP), analizando las propiedades psicométricas de la versión portuguesa. Este es un instrumento de evaluación de empatía en parejas, que resultó de la adaptación de una de las más usadas escalas de empatía, el Índice de Reactividad de Davis, para el contexto de las relaciones íntimas. El IRIP evalúa dimensiones de empatía cognitiva (toma de perspectiva) y emocional (preocupación empática), importantes para la estabilidad y satisfacción de las relaciones conyugales. La escala original fue traducida al portugués y administrada a 148 sujetos que mantenían una relación amorosa desde hace por lo menos un año. La mayoría de los sujetos eran mujeres con una edad media de 27 años. Los resultados revelaron una estructura factorial semejante a la escala original, valores adecuados de consistencia interna (Cronbach’s α=.82) y buenos niveles de validación externa con una escala de ajustamiento diádico.Este projeto foi financiado pela Fundação BIAL (Bolsa com a referência: 87/12)info:eu-repo/semantics/publishedVersio

    Spent yeast waste streams as a sustainable source of bioactive peptides for skin applications

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    Spent yeast waste streams are a byproduct obtained from fermentation process and have been shown to be a rich secondary source of bioactive compounds such as phenolic compounds and peptides. The latter are of particular interest for skin care and cosmetics as they have been shown to be safe and hypoallergenic while simultaneously being able to exert various effects upon the epidermis modulating immune response and targeting skin metabolites, such as collagen production. As the potential of spent yeast’s peptides has been mainly explored for food-related applications, this work sought to understand if peptide fractions previously extracted from fermentation engineered spent yeast (Saccharomyces cerevisiae) waste streams possess biological potential for skin-related applications. To that end, cytotoxic effects on HaCat and HDFa cells and whether they were capable of exerting a positive effect upon the production of skin metabolites relevant for skin health, such as collagen, hyaluronic acid, fibronectin and elastin, were evaluated. The results showed that the peptide fractions assayed were not cytotoxic up to the highest concentration tested (500 µg/mL) for both cell lines tested. Furthermore, all peptide fractions showed a capacity to modulate the various target metabolites production with an overall positive effect being observed for the four fractions over the six selected targets (pro-collagen IαI, hyaluronic acid, fibronectin, cytokeratin-14, elastin, and aquaporin-9). Concerning the evaluated fractions, the overall best performance (Gpep > 1 kDa) was of an average promotion of 41.25% over the six metabolites and two cell lines assessed at a concentration of 100 µg/mL. These results showed that the peptide fractions assayed in this work have potential for future applications in skin-related products at relatively low concentrations, thus providing an alternative solution for one of the fermentation industry’s waste streams and creating a novel and highly valuable bioactive ingredient with encompassing activity to be applied in future skin care formulations.info:eu-repo/semantics/publishedVersio

    Synchrotron X-ray studies on polyamide composites prepared by reactive injection molding

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    Semicrystalline polyamide 6 (PA6) and composites on its basis are among the most frequently used polymer materials for highly demanding applications. The performance of these composites depends on the crystalline structure of the PA6 matrix in which two crystalline forms most frequently coexist: α- and γ-polymorphs. This work reports on the crystalline structure of a variety of composite materials produced by in-mold reactive polymerization of caprolactam in specially designed semi-automatic equipment for reactive processing of nylons (NYRIM), carried out in the presence of particulate mineral reinforcements (natural or-ganically treated aluminum silicates and synthetic titanosilicates), PA6 oriented monofilaments and textile structures of glass fibers. The morphology and the crystalline structure of all composites were studied by syn-chrotron X-ray diffraction. Transcrystalline PA6 layer was observed in all fibrous PA6 laminates whose struc-ture fine crystalline structure was accessed.Fundação para a Ciência e Tecnologia; German Synchrotorn Radiation Source - DESY, Hambur

    A general mechanism for signal propagation in the nicotinic acetylcholine receptor family

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    Nicotinic acetylcholine receptors (nAChRs) modulate synaptic activity in the central nervous system. The α7 subtype, in particular, has attracted considerable interest in drug discovery as a target for several conditions, including Alzheimer’s disease and schizophrenia. Identifying agonist-induced structural changes underlying nAChR activation is fundamentally important for understanding biological function and rational drug design. Here, extensive equilibrium and nonequilibrium molecular dynamics simulations, enabled by cloud-based high-performance computing, reveal the molecular mechanism by which structural changes induced by agonist unbinding are transmitted within the human α7 nAChR. The simulations reveal the sequence of coupled structural changes involved in driving conformational change responsible for biological function. Comparison with simulations of the α4β2 nAChR subtype identifies features of the dynamical architecture common to both receptors, suggesting a general structural mechanism for signal propagation in this important family of receptors
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