3,891 research outputs found

    Genetically modified animals for use in research and biotechnology

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    Transgenic animals are used extensively in the study of in vivo gene function, as models for human diseases and in the production of biopharmaceuticals. The technology behind obtaining these animals involves molecular biology techniques, cell culture and embryo manipulation; the mouse is the species most widely used as an experimental model. In scientific research, diverse models are available as tools for the elucidation of gene function, such as transgenic animals, knockout and conditional knockout animals, knock-in animals, humanized animals, and knockdown animals. We examined the evolution of the science for the development of these animals, as well as the techniques currently used in obtaining these animal models. We review the phenotypic techniques used for elucidation of alterations caused by genetic modification. We also investigated the role of genetically modified animals in the biotechnology industry, where they promise a revolution in obtaining heterologous proteins through natural secretions, such as milk, increasing the scale of production and facilitating purification, thereby lowering the cost of production of hormones, growth factors and enzyme

    Cohort study shows that peripheral dual energy x-ray absorptiometry is of limited epidemiologic use in prepubertal children

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    Aim: Peripheral methods are increasingly used to assess bone health, despite little evidence on their predictive ability. We aimed to evaluate the usefulness of forearm dual‐energy X‐ray absorptiometry in prepubertal children, by estimating the agreement between peripheral and central measures and the ability to predict fracture history. Methods: In 2012/2014, we assessed 1177 seven‐year‐old children from the Generation XXI cohort who were recruited at birth in all five public hospitals with maternity wards in Porto, Portugal. Subtotal and lumbar spine bone mineral density (BMD) and content, left‐arm BMD and peripheral forearm BMD were measured. Parents reported the child's lifetime fracture history. We estimated agreement using Bland–Altman's method and Cohen's kappa. Fracture prediction ability was calculated using area under the receiver operator characteristic curve (ROC‐AUC). Results: The limits of agreement were very wide, ranging from −2.20/2.20 to −1.87/1.87 standard deviations for the comparison between peripheral and central measures. Categorical agreement was also poor, with all kappa values below 0.40. In addition, none of the measures predicted fractures, because all the ROC‐AUCs were close to 0.50. Conclusion: This study suggests that forearm BMD has limited use for bone health research or as a basis for clinical decisions in prepubertal children.Generation XXI was funded by FEDER through the Operational Programme Competitiveness and Internationalization and by national funds through the FCT – Fundação para a Ciência e a Tecnologia via grants POCI-01-0145-FEDER-016838 and POCI-01-0145-FEDER-016837, under the projects PTDC/DTP-EPI/1687/2014 and PTDC/DTP-EPI/3306/2014. Support by Administração Regional de Saúde Norte (Ministry of Health), Fundação Calouste Gulbenkian and Unidade de Investigação em Epidemiologia – Instituto de Saúde Pública da Universidade do Porto (EPIUnit) (POCI-01-0145-FEDER-006862; UID/DTP/04750/2013) is also acknowledged. TM and RL were supported by grants BD/92370/2013 and BPD/88729/2012 and co-funded by FCT and the POPH/FSE Programme and AM by the MSD merit scholarship to the Masters in Public Health of Universidade do Porto

    Food by-product valorization by using plant-based coagulants combined with AOPs for agro-industrial wastewater treatment

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    Re-using and adding value to by-products is one of the current focuses of the agri-food industry, following the Sustainable Development Goals of United Nations. In this work, the by-products of four plants, namely chestnut burr, acorn peel, olive leaf, and grape stem were used as coagulants to treat elderberry wastewater (EW), a problematic liquid effluent. EW pre-treatment using these natural coagulants showed promising results after pH and coagulant dosage optimization. However, the decrease in total organic carbon (TOC) was not significant, due to the addition of the plant-based natural coagulants which contain carbon content. After this pre-treatment, the photo-Fenton advanced oxidation process was selected, after preliminary assays, to improve the global performance of the EW treatment. Photo-Fenton was also optimized for the parameters of pH, H2O2, Fe2+, and irradiance power, and the best conditions were applied to the EW treatment. Under the best operational conditions defined in the parametric study, the combined results of coagulation–flocculation–decantation (CFD) and photo-Fenton for chestnut burr, acorn peel, olive leaf, and grape stem were, respectively, 90.2, 89.5, 91.5, and 88.7% for TOC removal; 88.7, 82.0, 90.2 and 93.1%, respectively, for turbidity removal; and finally, 40.6, 42.2, 45.3, and 39.1%, respectively, for TSS removal. As a final remark, it is possible to suggest that plant-based coagulants, combined with photo-Fenton, can be a promising strategy for EW treatment that simultaneously enables valorization by adding value back to food by-products.Fundação para a Ciência e a Tecnologia | Ref. PD/BD/135332/2017Fundação para a Ciência e a Tecnologia | Ref. UIDB/04033/2020Fundação para a Ciência e a Tecnologia | Ref. UIDB/00616/2020Fundação para a Ciência e a Tecnologia | Ref. UIDB/04129/202

    A shared biomechanical environment for bone and posture development in children

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    Background Context: In each specific habitual standing posture, gravitational forces determine the mechanical setting provided to skeletal structures. Bone quality and resistance to physical stress is highly determined by habitual mechanical stimulation. However, the relationship between bone properties and sagittal posture has never been studied in children. Purpose: This study aimed to investigate the association between bone physical properties and sagittal standing postural patterns in 7-year-old children. We also analyzed the relationship between fat or fat-free mass and postural patterns. Study Design: Cross-sectional evaluation. Patient Sample: This study was performed in a sample of 1,138 girls and 1,260 boys at 7 years of age participating in the Generation XXI study, a population-based cohort of children followed since birth (2005–2006) and recruited in Porto, Portugal. Outcome Measures: Sagittal standing posture was measured through photographs of the sagittal right view of children in the standing position. Three angles were considered to quantify the magnitude of major curves of the spine and an overall balance measure (trunk, lumbar, and sway angles). Postural patterns were identified using latent profile analysis in Mplus. Methods: Weight and height were measured. Total body less head fat or fat-free mass and bone properties were estimated from whole-body dual-energy X-ray absorptiometry scans. The associations of fat or fat-free mass and bone physical properties with postural patterns were jointly estimated in latent profile analysis using multinomial logistic regressions. Results:The identified patterns were labeled as Sway, Flat, and “Neutral to Hyperlordotic” (in girls), and “Sway to Neutral,” Flat, and Hyperlordotic (in boys). In both genders, children in the Flat pattern showed the lowest body mass index, and children with a rounded posture presented the highest: mean differences varying from −0.86 kg/m2 to 0.60 kg/m2 in girls and from −0.70 kg/m2 to 0.62 kg/m2 in boys (vs. Sway or “Sway to Neutral”). Fat and fat-free mass were inversely associated with a Flat pattern and positively associated with a rounded posture: odds ratio (OR) of 0.23 per standard deviation (SD) fat and 0.70 per SD fat-free mass for the Flat pattern, and 1.85 (fat) and 1.43 (fat-free) for the Hyperlordotic pattern in boys, with similar findings in girls. The same direction of relationships was observed between bone physical properties and postural patterns. A positive association between bone (especially bone mineral density) and a rounded posture was robust to adjustment for age, height, and body composition (girls: OR=1.79, p=.006 fat-adjusted, OR=2.00, p=.014 fat-free mass adjusted; boys: OR=2.02, p=.002 fat-adjusted, OR=2.42, p<.001 fat-free mass adjusted). Conclusions: In this population-based pediatric setting, there was an inverse association between bone physical properties and a Flat posture. Bone and posture were more strongly positively linked in a rounded posture. Our results support that both bone properties and posture mature in a shared and interrelated mechanical environment, probably modulated by pattern-specific anthropometrics and body composition.Generation XXI was funded by FEDER through the Operational Programme Competitiveness and Internationalization and by national funds through the FCT – Fundação para a Ciência e a Tecnologia via grants POCI-01-0145-FEDER-016838 and POCI-01-0145-FEDER-016837, under the projects PTDC/DTP-EPI/1687/2014 and PTDC/DTP-EPI/3306/2014. Support by Administração Regional de Saúde Norte (Ministry of Health), Fundação Calouste Gulbenkian and Unidade de Investigação em Epidemiologia - Instituto de Saúde Pública da Universidade do Porto (EPIUnit) (POCI-01-0145-FEDER-006862; UID/DTP/04750/2013) is also acknowledged. Araújo FA and Lucas R were supported by grants SFRH/BD/85398/2012 and SFRH/BPD/88729/2012, co-funded by FCT and the POPH/FSE. The authors also gratefully acknowledge the families enrolled in Generation XXI, and the contribution of the members of the research team and staff

    Massive open star clusters using the VVV survey II. Discovery of six clusters with Wolf-Rayet stars

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    Context: The ESO Public Survey "VISTA Variables in the V\'ia L\'actea" (VVV) provides deep multi-epoch infrared observations for an unprecedented 562 sq. degrees of the Galactic bulge, and adjacent regions of the disk. In this survey nearly 150 new open clusters and cluster candidates have been discovered. Aims: This is the second in a series of papers about young, massive open clusters observed using the VVV survey. We present the first study of six recently discovered clusters. These clusters contain at least one newly discovered Wolf-Rayet (WR) star. Methods: Following the methodology presented in the first paper of the series, wide-field, deep JHKs VVV observations, combined with new infrared spectroscopy, are employed to constrain fundamental parameters for a subset of clusters. Results: We affirm that the six studied stellar groups are real young (2-7 Myr) and massive (between 0.8 and 2.2 10^3 Msol) clusters. They are highly obscured (Av ~ 5-24 mag) and compact (1-2 pc). In addition to WR stars, two of the six clusters also contain at least one red supergiant star. We claim the discovery of 8 new WR stars, and 3 stars showing WR-like emission lines which could be classified WR or OIf. Preliminary analysis provides initial masses of ~30-50 Msol for the WR stars. Finally,we discuss the spiral structure of the Galaxy using as tracers the six new clusters together with the previously studied VVV clusters.Comment: 17 pages, 8 figurs, accepted in A&

    SpectraNet–53: A deep residual learning architecture for predicting soluble solids content with VIS–NIR spectroscopy

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    This work presents a new deep learning architecture, SpectraNet-53, for quantitative analysis of fruit spectra, optimized for predicting Soluble Solids Content (SSC, in Brix). The novelty of this approach resides in being an architecture trainable on a very small dataset, while keeping a performance level on-par or above Partial Least Squares (PLS), a time-proven machine learning method in the field of spectroscopy. SpectraNet-53 performance is assessed by determining the SSC of 616 Citrus sinensi L. Osbeck 'Newhall' oranges, from two Algarve (Portugal) orchards, spanning two consecutive years, and under different edaphoclimatic conditions. This dataset consists of short-wave near-infrared spectroscopic (SW-NIRS) data, and was acquired with a portable spectrometer, in the visible to near infrared region, on-tree and without temperature equalization. SpectraNet-53 results are compared to a similar state-of-the-art architecture, DeepSpectra, as well as PLS, and thoroughly assessed on 15 internal validation sets (where the training and test data were sampled from the same orchard or year) and on 28 external validation sets (training/test data sampled from different orchards/years). SpectraNet-53 was able to achieve better performance than DeepSpectra and PLS in several metrics, and is especially robust to training overfit. For external validation results, on average, SpectraNet-53 was 3.1% better than PLS on RMSEP (1.16 vs. 1.20 Brix), 11.6% better in SDR (1.22 vs. 1.10), and 28.0% better in R2 (0.40 vs. 0.31).project NIBAP ALG-01-0247-FEDER-037303, project OtiCalFrut ALG-010247-FEDER-033652info:eu-repo/semantics/publishedVersio

    Beta-fibrilose encefálica e cardíaca em idosos autopsiados

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    INTRODUCTION: Amyloidosis in elderly individuals can be an independent alteration and a characteristic of aging. However, the clinical, pathophysiologic, and biochemical characteristics of amyloidosis related to age remain uncertain. OBJECTIVE: The purpose of this study was to determine the extent to which the heart and/or the brain of individuals aged 60 years or over exhibits amyloid deposits. MATERIALS AND METHODS: The autopsy findings of individuals who were at least 60 years old were studied. The autopsies took place between the years of 1976 and 2000. A total of 10 cases were selected that had hearts without cardiopathies, had negative serology for Chagas' disease, and had brains without morphological changes related to encephalopathies. Slides with fragments of heart and brain were processed and analyzed using polarized and common light microscopy. RESULTS: Of the 10 cases, 4 were positive for amyloidosis. All had positive findings in the brain, and 1 case also had positive findings in the heart. Among the positive cases, 50% were of people aged 60 to 69 years. There appeared to be a relationship between the presence of amyloid deposits and the ratio of brain and body weight, with the ratio in the positive cases being smaller than in the negative cases. CONCLUSIONS: The analysis of amyloid deposits in the brains and hearts of elderly individuals shows that such deposits may lead to a systemic attack of senility, common to natural aging. It is not certain that beta-amyloid deposits would alone bring such drastic repercussions to the individual. Some additional disorders of the organism could cause the breakdown of the natural balance related to the accumulation of these proteins, leading the way to the pathological contexts of amyloidosis.RESUMO INTRODUÇÃO: A amiloidose em idosos pode ser uma alteração independente e própria do envelhecimento. Entretanto, as características clínicas, fisiopatológicas e bioquímicas da Amiloidose relacionada à idade ainda permanecem incertas. OBJETIVO: Verificar se o coração e o encéfalo de indivíduos acima de 60 anos apresentavam depósito amilóide. MATERIAL E MÉTODOS: Foram estudados laudos consecutivos de autópsias de indivíduos acima de 60 anos realizadas entre 1976 e 2000, que apresentavam corações sem cardiopatias, com sorologia negativa para Doença de Chagas e encéfalos sem alterações morfológicas de encefalopatias, chegando a um n de 10 casos. Lâminas de fragmentos do coração e de encéfalo foram processadas e analisadas em microscopia de luz comum e polarizada. RESULTADOS: Dos 10 casos, 3 apresentaram depósito amilóide no encéfalo e 1 no encéfalo e no coração. Em 50% dos casos, os indivíduos tinham entre 60 e 69 anos. A relação entre o peso encefálico e o peso corporal mostrou ter uma associação significativa com os casos positivos, sendo esta menor em relação aos negativos. CONCLUSÃO: A análise conjunta de depósitos amilóides em encéfalo e coração de indivíduos idosos talvez direcione para um acometimento sistêmico comum ao envelhecimento natural. Alguma alteração adicional do organismo poderia determinar a quebra de um equilíbrio natural sobre o acúmulo dessas proteínas, levando dessa forma aos contextos patológicos da amiloidose
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