605 research outputs found
Genomic Template Stability assessed in almond trees of cv. ‘Vairo’ treated with biostimulants and boron-based fertilizers
Almond is highly produced in the NE of Portugal, where late frosts during flowering, low precipitation, and high temperature in summer affect productivity and quality. In addition to late-flowering cultivars, plant biostimulants (PBs) and boron-based fertilizers have been used to improve cell division, vegetative growth, photoassimilates rate, and nutritional status of almond trees. Despite the wide use of PBs in multiple food crops, the scientific evaluation of their effects is scarce. Our team previously analyzed the effects of PBs and boron-based fertilizers in the mitotic cell cycle of almonds and verified the intensification of cell division without significant anomalies. This work focused on the molecular characterization of three-years-old almond trees of cv. ‘Vairo’ was treated with two PBs (based on seaweed extract and free amino acids) and two boron-based fertilizers (applied on soil and leaves) in a rainfed orchard (NE Portugal) using leaf samples collected through the summer of 2019 in treated trees. Three monthly applications of individual PBs based on seaweed extract (AN), amino acids (AA), and boron ethanolamine (BE) and a unique application of boron on the soil (BS) were made. The molecular stability was assayed by comparing with untreated trees using ISSR, RAPD, IRAP, REMAP, and iPBS markers. The molecular data achieved in ‘Vairo,’ under the edaphoclimatic conditions where it was studied, revealed that AA, BE, or BS treatments induced higher molecular stability, corroborating our previous cytogenetic results.This work was supported by National Funds by the FCT – Portuguese Foundation for Science and Technology under the project UIDB/04033/2020. Author AC thanks to the FCT and UTAD for her contract as a researcher under the scope of D.L. no. 57/2016 of 29 August and Law no. 57/2017 of 19 July.info:eu-repo/semantics/publishedVersio
The effects of the use of organic solid wastes on the growth of citrus trees
Two types of organic solid wastes were selected to be applied in a citrus orchard: the sewage sludge (the most common on the settlements) and the manure (the most common on the agricultural fields). The sewage sludge is a residue originated from the wastewater treatment - the solid phase. Its application as an organic fertilizer may represent an alternative to the pollution effects in nature. In an orchard of orange-trees (Citrus sinensis [L.] Osbeck), the application of sludge was compared with the application of manure and with the control in order to observe the growth response of the trees. Biometric methods where used - number of leaves per tree, diameter of the trunk, leaf area, specific leaf areas and leaf chlorophyll content. In general, the citrus plants response to the application of sewage sludge and manure was positive for the plant growth, compared to the control. The application of the manure, and especially the sewage sludge (once this fertilizer / soil amendment is available in larger amounts) may be a profitable alternative application to the use of mineral fertilizers and to other soil amendments. Moreover, as the possible destinations of sewage sludge (sea, deposition in land fields, incineration) provoke environmental problems, its agricultural reuse is essential to avoid those problems, when correctly applied in relation to trace elements and to pathogenic parameters. The reuse of this solid waste may be a clean and a safe technique to preserve the environment contamination
Mudanças no diagnóstico pré-natal cromossómico: indicações clínicas, amostras biológicas, metodologias e cromossomopatias
Introdução: As mudanças no diagnóstico pré-natal de anomalias cromossómicas (DPN) nos últimos 10-15 anos foram contínuas e significativas.
Objetivos: Propômo-nos analisar essa evolução: mudanças nas indicações clínicas; introdução das biópsias de vilosidades coriónicas (BVC); utilização do diagnóstico rápido de aneuploidias (DRA); estudos por microarray; alterações cromossómicas encontradas.
Metodologia: Fez-se a avaliação retrospetiva nas gestações com amostras estudadas nos triénios 2004-2006 e 2014-2016. Analisaram-se os parâmetros indicação clínica, tipo de amostra, metodologias utilizadas e resultados.
Resultados: Identificaram-se 68 fetos com cariotipo anormal em 2210 cariotipos (3,1%) em 2004-2006 e 208 fetos com cariotipo anormal em 2315 cariotipos (9,0%) em 2014-2016.
A maior frequência de anomalias encontrou-se nos casos de rastreios ecográficos e combinados indicativos de risco acrescido de anomalia numérica e de progenitores portadores de alterações cromossómicas.
As BVC permitiram respostas precoces nas gestações com anomalias numéricas e, adicionalmente, um aumento desses cariotipos (7.5% das amostras).
O DRA permitiu ter uma resposta rápida nas anomalias numéricas mais frequentes (2 dias).
As anomalias estruturais foram menos preponderantes nos cariotipos anormais (32,4% em 2004-2006 e 14.4% em 2014-2016).
Discussão e conclusões: O DRA reduziu o tempo de resposta e das decisões sobre o futuro das gestações. O microarray permitiu identificar alterações sindromáticas em situações não resolúveis por outras metodologias.
A utilização de BVC permite estabelecer uma melhor correlação fenotipo-genotipo em menores idades gestacionais.
No entanto, as gestações com anomalias numéricas têm algum risco de perda fetal no primeiro e início do segundo trimestres. Assim, algumas BVC com cariotipos anormais resultariam em perdas espontâneas, o que poderia disponibilizar outros casos para DPN.
Por outro lado, o menor número de anomalias estruturais equilibradas encontrado pode reduzir o conhecimento da variação genética nas famílias e na população.
Um novo paradigma resulta da implementação dos testes não invasivos no DPN, para os quais ainda não conhecemos todas as limitações e repercussões.N/
Microencapsulation Technology: A Powerful Tool for Integrating Expansion and Cryopreservation of Human Embryonic Stem Cells
The successful implementation of human embryonic stem cells (hESCs)-based technologies requires the production of relevant numbers of well-characterized cells and their efficient long-term storage. In this study, cells were microencapsulated in alginate to develop an integrated bioprocess for expansion and cryopreservation of pluripotent hESCs. Different three-dimensional (3D) culture strategies were evaluated and compared, specifically, microencapsulation of hESCs as: i) single cells, ii) aggregates and iii) immobilized on microcarriers. In order to establish a scalable bioprocess, hESC-microcapsules were cultured in stirred tank bioreactors
Chromosomal disorders and male infertility
Male factor infertility is considered a complex disorder with a largely unknown etiology that affects about 7% of men. In general, genetic abnormalities account for 15%-30% of condition and Y chromosome microdeletions are also frequent.
The study, based on our casuistic, aimed at contributing to a better understanding of the genetic causes of infertility.
A group of 410 idiopathic infertile men with non-obstructive azoospermia, oligozoospermia, or unknown semen quality (based on clinical evaluation and/or sperm counts) was retrospectively selected. Conventional karyotype was performed in all samples; Y microdeletion screen was performed in 247 samples.
Forty two abnormal karyotypes (10.2%) were found, indicating an elevated frequency of chromosome abnormalities among the selected infertile men, as compared to that of newborn populations (≈0.4%). This frequency is higher than that reported in most similar studies that pointed to frequencies ranging from 2.2%-14.3%.
Klinefelter´s syndrome was the most common chromosome disorder (4.9%). There were 18 cases with 47,XXY karyotype and 2 cases of mosaicism involving lines 47,XXY and 46,XY. Reciprocal translocations were identified in 10 cases (2.4%), particularly in men with unknown semen quality. Overall, reciprocal translocations have been found in approximately 1% of the infertile men and more commonly in azoospermics than in oligozoospermics. However, this type of association was not found in the present study.
On the other hand, Y microdeletions were identified in 16/247 cases (6.5%), more frequently in azoospermics (13.3%, corresponding to 8/60 azoospermics). Among these 8 cases, 7 presented deletions at the AZFc region.
The marked presence of chromosomal abnormalities and Y microdeletions enphasizes the relevance of studying both factors in infertile men to improve genetic counseling, to allow the development of appropriate therapies, and to expand the knowledge about the ethiology of male infertility
Combining Hypoxia and Bioreactor Hydrodynamics Boosts Induced Pluripotent Stem Cell Differentiation Towards Cardiomyocytes
Cardiomyocytes (CMs) derived from induced pluripotent stem cells (iPSCs) hold great promise for patient-specific disease modeling, drug screening and cell therapy. However, existing protocols for CM differentiation of iPSCs besides being highly dependent on the application of expensive growth factors show low reproducibility and scalability. The aim of this work was to develop a robust and scalable strategy for mass production of iPSC-derived CMs by designing a bioreactor protocol that ensures a hypoxic and mechanical environment. Murine iPSCs were cultivated as aggregates in either stirred tank or WAVE bioreactors. The effect of dissolved oxygen and mechanical forces, promoted by different hydrodynamic environments, on CM differentiation was evaluated. Combining a hypoxia culture (4 % O(2) tension) with an intermittent agitation profile in stirred tank bioreactors resulted in an improvement of about 1000-fold in CM yields when compared to normoxic (20 % O(2) tension) and continuously agitated cultures. Additionally, we showed for the first time that wave-induced agitation enables the differentiation of iPSCs towards CMs at faster kinetics and with higher yields (60 CMs/input iPSC). In an 11-day differentiation protocol, clinically relevant numbers of CMs (2.3 × 10(9) CMs/1 L) were produced, and CMs exhibited typical cardiac sarcomeric structures, calcium transients, electrophysiological profiles and drug responsiveness. This work describes significant advances towards scalable cardiomyocyte differentiation of murine iPSC, paving the way for the implementation of this strategy for mass production of their human counterparts and their use for cardiac repair and cardiovascular research. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12015-014-9533-0) contains supplementary material, which is available to authorized users
Portuguese study of familial dilated cardiomyopathy: the FATIMA study
Dilated cardiomyopathy (DCM) is a myocardial disease, characterized by ventricular dilatation and impaired systolic function, that in more than 30% of cases has a familial or genetic origin. Given its age-dependent penetrance, DCM frequently manifests in adults by signs or symptoms of heart failure, arrhythmias or sudden death. The predominant mode of inheritance is autosomal dominant, and in these cases mutations are identified in genes coding for cytoskeletal, sarcomeric or nuclear envelope proteins. To date, most studies aimed at molecular diagnosis of DCM have been in selected families, or in larger groups of patients, but screening for mutations in a limited number of genes. Consequently, the epidemiology of mutations in familial DCM remains unknown. There is thus a need for multicenter studies, involving screening for a wide range of mutations in several families and in cases of idiopathic DCM. The present article describes the methodology of a multicenter study, aimed at clinical and molecular characterization of familial DCM patients in the Portuguese population.A miocardiopatia dilatada (MCD) é uma
doença do músculo cardíaco caracterizada pela
dilatação ventricular e compromisso da função
sistólica, sendo possível identificar, numa
percentagem superior a 30% dos casos, uma
origem familiar ou genética. Dada a
penetrância dependente da idade, manifesta-se
muitas vezes em adultos por sinais ou sintomas
de insuficiência cardíaca, arritmias ou morte
súbita. O padrão autossómico dominante
predomina, sendo possível identificar, nestes
casos, mutações em genes de proteínas do
citoesqueleto celular, sarcómero ou membrana
nuclear.
Até ao momento, a maioria dos trabalhos
visando o diagnóstico molecular nos casos de
MCD foi realizada em famílias seleccionadas,
ou em grupos mais abrangentes de doentes,
mas rastreando mutações num número restrito
de genes.
Consequentemente a epidemiologia das
mutações nos casos familiares de MCD
continua por esclarecer. É neste contexto que
se coloca a necessidade de efectuar estudos
multicêntricos, envolvendo uma pesquisa
mutacional diversificada em várias familias e
nos casos idiopáticos de MCD.
O presente artigo descreve a metodologia de
um estudo multicêntrico que tem como
objectivo a caracterização clínica e molecular
de casos familiares de MCD na população
portuguesa
Review on the EFDA work programme on nano-structured ODS RAF steels
This proceeding is: The 14th International Conference on Fusion Reactor Materials (ICFRM-14) was held at the Sapporo Convention Center in Sapporo, Japan from 7 to 12 September 2009.The 2008─2009 work programme of the European research project on nano-structured oxide dispersion strengthened (ODS) reduced activation ferritic (RAF) steels is being organized along the four following programmatic lines: (1) improve the present generation of nano-structured ODS RAF steels; (2) start the industrial fabrication of the present generation of nano-structured ODS RAF steels; (3) develop an optimised generation of nano-structured and nano-grained ODS RAF steels; (4) investigate the stability of present and optimised generation of nano-structured ODS RAF steels under creep and irradiation. This paper presents the main objectives of current R&D activities being performed within the European research project on nano-structured ODS RAF steels, the main obtained results and the main future activities in the case of the four programmatic lines mentioned just above.This work, supported by the European Communities, was carried out within the framework of the European Fusion Development Agreement.Publicad
Eutrophication-threatened aquatic ecosystems : sediment biogeochemical processes towards nutrients control
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