2,848 research outputs found

    MicroRNAs and metastases--the neuroblastoma link

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    [Excerpt] MicroRNAs (miRNAs) are small noncoding RNAs of approximately 22 nucleotides in length that regulate gene expression post-transcriptionally. These small RNAs are fundamental regulators of several cellular processes, such as differentiation, development, apoptosis, proliferation, cell cycle regulation and metabolism, through the binding to 3' untranslated regions, coding sequence or 5' untranslated regions of target messenger RNAs (mRNAs), preventing their translation or causing their degradation.1 A modest change in only one miRNA will affect multiple mRNA targets; consequently, the deregulation of miRNAs has important consequences to the cellular homeostatic stability, and aberrant miRNAs expression patterns have been described in several types of cancer.2 Recently, miRNAs have been implicated in the metastatic process of several tumors such as human breast and colorectal cancers3 and, as reported this issue of Cancer Biology & Therapy by Guo et al. in neuroblastoma.4 These are extracranial solid tumors, arising from neural crest cells, that are most common in infants and children; metastasis, the main cause of death, is present at the time of diagnosis in approximately 60% of patients. (5) [...

    A method to discriminate species of virus vector trichodorid nematodes exploring 18S rDNA region

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    European Consortium for the Barcode Of Life (ECBOL

    Ética do trabalho em estudantes do ensino superior policial

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    O valor atribuído ao trabalho sofreu três mutações maiores ao longo do devir histórico-social: a seguir ao valor intrínseco, característico da ética romântica (ER) da civilização rural, emergiu o valor extrínseco, característico da ética materialista da civilização urbana e industrial, seguido da actual integração de ambos os tipos de valores, característica da ética de desenvolvimento pessoal. Foram realizados dois estudos com estudantes dos primeiros quatro anos do Curso Mestrado Integrado em Ciências Policiais (ano lectivo de 2009/2010; N = 158). O primeiro mostrou a coexistência das três éticas do trabalho. O segundo mostrou diferenças na influência das três éticas sobre as classificações na unidade curricular de Instrução do Corpo de Alunos: positiva no caso da ER e negativa no caso das outras duas éticas. Os modelos de equações estruturais que formalizaram as relações entre as variáveis destes estudos foram testados a partir do modelo de medida operacionalizado pela Escala de Crenças Relativas ao Trabalho – Revista. Discutem-se os resultados encontrados e as limitações dos estudos à luz da teoria das éticas do trabalho e da teoria da modelação de equações estruturais

    Prevalence of shigatoxigenic Escherichia coli in bovine cattle: a survey in the north region of portugal

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    Shiga toxin-producing Escherichia coli (STEC) strains are food-borne pathogens that can be transmitted to humans through many different routes, but mainly through consumption of contaminated foods. STEC strains are characterized by the production of Shiga toxins (Stx) that are encoded by two genes stx1 and/or stx2. Each toxin can be subdivided into subtypes and, currently, there are three known subtypes for stx1 (stx1a, stx1c, and stx1d) and seven for stx2 (stx2a, stx2b, stx2c, stx2d, stx2e, stx2f, and stx2g). Others virulence factors, such the production of intimin protein, encoded by eae gene, are associated with severe outcomes of STEC-associated diseases. The most common STEC serotype implicated worldwide is E. coli O157:H7, but many other STEC strains are associated with severe human diseases. Ruminants, especially cattle, are a major reservoir for O157 and non-O157 STEC. Information on STEC prevalence in Portuguese dairy cattle is limited, so we analysed for the presence of STEC 329 faecal specimens collected from the rectum of healthy dairy cattle. The samples were collected from adults lactating cows (n=194) and from heifers (n=135) with ages among 6 to 18 months, between March and June 2019, at milk farms (n=17) in the North region of Portugal. After enrichment, in modified TSB with novobiocin, samples were analysed by real time PCR to detect the presence of stx1, stx2 and eae in accordance to ISO/TS 13136:2012(E). In addition, conventional PCR for the detection of sxt1 and stx2 gene subtypes was performed according to the guidelines of the VTEC European Union Reference Laboratory. A total of 139 isolates were recovered from 108 positive animals (dairy cows and heifers). The STEC prevalence was significantly higher in heifers (68/135; 50.4%) than in adult cows (40/194; 20.6%) (p < 0.05, Fisher exact test statistic value is <0.00001). STEC harbouring only stx2 (67/139; 48.2%) were the most common strains, followed by both genes stx1 and stx2 (40/139, 28.8%) and stx1 (32/139, 23%). Of the 139 STEC isolates, 35.3% have also the eae gene. Subtyping of stx1 (72) showed that stx1a was the most prevalent (100%), followed by stx1c (88.9%) and stx1d (6.9%). Stx1a and stx1c subtypes occurred alone or combination with other subtypes. However, subtype stx1d was only found in combination with subtype stx1a and or stx1c. Concerning strains with stx2 (107), the stx2a subtype was the most common and was found in 84.1% of the isolates, followed by stx2d (76.6%), stx2c (74.8%), stx2g (23.4%), stx2b (4.7%), stx2e (3.7%) and stx2f (0.9%). No strains carried stx2b or stx2f alone. For isolates carrying stx1 and stx2 simultaneously, combinations of subtypes stx1a, stx1c, stx2a, stx2c and stx2d were the most common. Furthermore, in 42 isolates (30.2%) 4 or more stx subtypes were detected simultaneously. These results show that STEC prevalence in dairy cattle is high, and that most isolates present a diverse combination of Shiga-toxin genes. Future strategies are needed to mitigate the presence of STEC in cattle and then reduce the possible contamination of food and, thus, humans.Project PhageSTEC (POCI-01-0145-FEDER-029628) funded by FEDER through COMPETE2020 (Programa Operacional Competitividade e Internacionalização) and by National Funds thought FCT (Fundação para a Ciência e a Tecnologia).info:eu-repo/semantics/publishedVersio

    Removal of the hormones 17β-estradiol and 17α-ethinylestradiol from aqueous solutions employing a decomposed peat as adsorbent material

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    REMOVAL OF THE HORMONES 17b-ESTRADIOL AND 17a-ETHINYLESTRADIOL FROM AQUEOUS SOLUTIONS EMPLOYING A DECOMPOSED PEAT AS ADSORBENT MATERIAL. This paper describes the adsorption of 17b-estradiol (E2) and 17a-ethinylestradiol (EE2) from aqueous solution by decomposed peat. The peat presented a good adsorption process, close to 76.2% for E2 removal and approximately 55.0% for EE2. Moreover, the results indicated a probable multi-layered process. Adsorption isotherms were well fitted by Freundlich model. The data were evaluated considering the pseudo-first-order and pseudo-second-order approaches, being the second more significant mechanism in the rate-controlling step. Thermodynamic data revealed that hormones adsorption onto peat is spontaneous under the employed experimental conditions. The results confirmed the potential of this adsorbent to be employed for effluents treatment

    Platelet lysate cell-laden hydrogel-coated suture threads for tendon repair

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    Tendon injuries constitute a major healthcare burden owing to the limited healing ability of these tissues and the poor clinical outcomes of surgical repair treatments. Recent advances in tendon tissue engineering (TTE) strategies, particularly through the use of biotextile technologies, hold great promise toward the generation of artificial living tendon constructs. We have previously developed a braided construct based on suture threads coated with gelMA:alginate hydrogel encapsulating human tendon cells. These cell-laden composite fibers enabled the replication of cell and tissue-level properties simultaneously. Based on this concept, in this study we explored the use of platelet lysate (PL), a pool of supra-physiological concentrations of growth factors (GFs), to generate a hydrogel layer, which is envisioned to act as a depot of therapeutic factors to induce tenogenic differentiation of encapsulated human adipose stem cells (hASCs). For this purpose, commercially available suture threads were first embedded in a thrombin solution and then incubated in PL containing hASCs. Herein, thrombin induces the gelation of PL and consequent hydrogel formation. After coating suture threads with the mixture of PL-ASCs, cells were found to be viable and homogeneously distributed along the fibers. Strikingly, hASCs encapsulated within the PL hydrogel layer around the suture thread were able to sense chemotactic factors present in PL and to establish connections between adjacent independent fibers, suggesting a tremendous potential of PL cell-laden hydrogel fibers as building blocks in the development of living constructs aimed at tendon repair applications.info:eu-repo/semantics/publishedVersio

    Emotional responses to motion sickness in autonomous driving

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    In future autonomous cars, users, free from the primary task of driving, will have time and space to engage in other activities while traveling, such as reading a book, working on a laptop or watching a movie. Although the option for these activities are one of the great advantages of autonomous cars, this will also likely increase motion sickness (MS) inside the car. MS affects numerous individuals, and it occurs when the information received through the eyes differs from what is perceived by the body and the inner ear. Plus, MS can have an impact on the emotional component of the individuals experiencing it, making the experience of traveling in autonomous cars uncomfortable and difficult. Emotional design studies focus on the emotional response of individuals to a product or service. These studies typically employ self-report scales as assessment tools, such as SAM (Self-Assessment Manikin) and PrEmo (Product Emotion Measurement instrument). We present the first study measuring emotional responses to MS using both SAM and PrEmo scales. In our study, we induced MS by asking participants to watch a highly dynamic video of a first-person car trip. We also asked subjects to answer to SAM and PrEmo before and after the visualization of the video. Our results showed a change in the answers in time, that is, before vs. after the experience of MS. MS significantly altered individuals' emotional responses, worsening their condition. These results support the need for studies that reduce MS to improve the experience and well-being of individuals in autonomous cars.Landscape, Heritage and Territory Laboratory (Lab2PT), Ref. UID/04509/2020, financed by national funds (PIDDAC) through the FCT/MCTES and the European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project n° 039334; Funding Reference: POCI- 01-0247-FEDER-039334]

    Benchmarking recombinant Pichia pastoris for 3-hydroxypropionic acid production from glycerol

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    The use of the methylotrophic yeast Pichia pastoris (Komagataella phaffi) to produce heterologous proteins has been largely reported. However, investigations addressing the potential of this yeast to produce bulk chemicals are still scarce. In this study, we have studied the use of P. pastoris as a cell factory to produce the commodity chemical 3-hydroxypropionic acid (3-HP) from glycerol. 3-HP is a chemical platform which can be converted into acrylic acid and to other alternatives to petroleum-based products. To this end, the mcr gene from Chloroflexus aurantiacus was introduced into P. pastoris. This single modification allowed the production of 3-HP from glycerol through the malonyl-CoA pathway. Further enzyme and metabolic engineering modifications aimed at increasing cofactor and metabolic precursors availability allowed a 14-fold increase in the production of 3-HP compared to the initial strain. The best strain (PpHP6) was tested in a fed-batch culture, achieving a final concentration of 3-HP of 24.75 g l−1, a product yield of 0.13 g g−1 and a volumetric productivity of 0.54 g l−1 h−1, which, to our knowledge, is the highest volumetric productivity reported in yeast. These results benchmark P. pastoris as a promising platform to produce bulk chemicals for the revalorization of crude glycerol and, in particular, to produce 3-HP

    Efficacy, Stability, and Safety Evaluation of New Polyphenolic Xanthones Towards Identification of Bioactive Compounds to Fight Skin Photoaging

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    Antioxidants have long been used in the cosmetic industry to prevent skin photoaging, which is mediated by oxidative stress, making the search for new antioxidant compounds highly desirable in this field. Naturally occurring xanthones are polyphenolic compounds that can be found in microorganisms, fungi, lichens, and some higher plants. This class of polyphenols has a privileged scaffold that grants them several biological activities. We have previously identified simple oxygenated xanthones as promising antioxidants and disclosed as hit, 1,2-dihydroxyxanthone (1). Herein, we synthesized and studied the potential of xanthones with different polyoxygenated patterns as skin antiphotoaging ingredients. In the DPPH antioxidant assay, two newly synthesized derivatives showed IC₅₀ values in the same range as ascorbic acid. The synthesized xanthones were discovered to be excellent tyrosinase inhibitors and weak to moderate collagenase and elastase inhibitors but no activity was revealed against hyaluronidase. Their metal-chelating effect (FeCl₃ and CuCl₂) as well as their stability at different pH values were characterized to understand their potential to be used as future cosmetic active agents. Among the synthesized polyoxygenated xanthones, 1,2-dihydroxyxanthone (1) was reinforced as the most promising, exhibiting a dual ability to protect the skin against UV damage by combining antioxidant/metal-chelating properties with UV-filter capacity and revealed to be more stable in the pH range that is close to the pH of the skin. Lastly, the phototoxicity of 1,2-dihydroxyxanthone (1) was evaluated in a human keratinocyte cell line and no phototoxicity was observed in the concentration range tested.This research was supported by national funds through FCT, Foundation for Science and Technology, within the scope of UIDB/04423/2020 and UIDP/04423/2020 under the project PTDC/SAU-PUB/28736/2017 (reference POCI-01-0145-FEDER-028736), cofinanced by COMPETE 2020, Portugal 2020 and the European Union through the ERDF and by FCT through national funds, as well as CHIRALBIOACTIVE-PI-3RL-IINFACTS-2019, and supported by the Applied Molecular Biosciences Unit-UCIBIO which is financed by national funds from FCT/MCTES (UID/Multi/04378/2019). Thanks are also due to FCT, the European Union, QREN, FEDER, COMPETE, by funding cE3c center (Ref. UID/BIA/00329/2019) and Direcao Regional da Ciencia e Tecnologia (Azores Government) by funding Azorean Biodiversity Group.info:eu-repo/semantics/publishedVersio
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