117,495 research outputs found
METABOLOMICS APPLIED TO BIOMARKER DISCOVERY IN RESPIRATORY OUTCOME OF PRETERM INFANTS
No full textBackground: Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease in preterm infants. Despite significant improvements in neonatal intensive care, its incidence is still increasing. The long-term respiratory and neurological consequences of BPD have a major impact on survivors' quality of life. Currently, there is still no specific treatment once BPD is established, so it is important to identify children at risk in the first days of life. Metabolomics is the most recent "omics" science and allows the identification and quantification of all metabolites present in a complex biological system. The application of the metabolomic approach to diseases permits the identification of characterizing metabolites, even unknown ones, which help to understand the pathogenetic mechanisms underlying the disease and potentially can become a diagnostic tool.
Aim of the study: The aim of the study is to apply the metabolomic approach in order to establish whether a biomarker profile exists at birth, capable of predicting the development of BPD in preterm infants. The secondary aim is to characterized the urinary metabolome of BPD patients at birth.
Materials and Methods: This is a monocentric prospective observational case-control study. It was conducted at the Neonatal Intensive Care Unit (NICU), Hospital-University of Padova, Padova, Italy.
Premature neonates admitted to the NICU, born at less than 32 weeks' gestational age (GA) have been enrolled. Patients who develop BPD were enrolled as cases, patients without BPD as controls. BPD was defined as need for oxygen supplementation for at least 28 days. Urine sample was collected within 48 hours of life for each patient and untargeted metabolic analysis was performed with ultra performance liquid chromatography system coupled to a Quadrupole Time-of-Flight mass spectrometer.
Results: 161 neonates have been enrolled, of that 69 with BPD (42.9%) and 92 without BPD (57.1%). The median GA at birth was 29 (27-31) weeks and the median birth weight 1115 (800-1400) g. Urine untargeted metabolomic revealed a metabolites clustering in BPD neonates in comparison to neonates without BPD. The metabolomic derangements concerned metabolites belonging to the acylcarnitine class, uridine and pseudouridine. To control the effect GA on metabolome, 11 infants with BPD were matched with 11 without BPD of comparable GA. After adjusting the analysis for GA, the main discriminating metabolites were: L-cystathionine, isovalerylcarnitine, creatine, p-hydroxyphenylacetic acid. Compared to clinical data alone, the application of urinary metabolome analysis at birth increases the sensitivity and specificity in the prediction of BPD, respectively from 86.7% to 90.0% and from 84.0% to 86.0%.
Conclusions: The metabolomic approach on urine collected within 48 hours of life revealed an interesting clustering of metabolites that discriminates between preterm infants at risk of developing BPD versus infants who will not develop it. The analysis of the identified metabolites at birth increases the prediction of BPD development in preterm infants. In the next future, early detection of infants at risk of developing BPD may be useful for the administration of targeted therapies.Background: Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease in preterm infants. Despite significant improvements in neonatal intensive care, its incidence is still increasing. The long-term respiratory and neurological consequences of BPD have a major impact on survivors' quality of life. Currently, there is still no specific treatment once BPD is established, so it is important to identify children at risk in the first days of life. Metabolomics is the most recent "omics" science and allows the identification and quantification of all metabolites present in a complex biological system. The application of the metabolomic approach to diseases permits the identification of characterizing metabolites, even unknown ones, which help to understand the pathogenetic mechanisms underlying the disease and potentially can become a diagnostic tool.
Aim of the study: The aim of the study is to apply the metabolomic approach in order to establish whether a biomarker profile exists at birth, capable of predicting the development of BPD in preterm infants. The secondary aim is to characterized the urinary metabolome of BPD patients at birth.
Materials and Methods: This is a monocentric prospective observational case-control study. It was conducted at the Neonatal Intensive Care Unit (NICU), Hospital-University of Padova, Padova, Italy.
Premature neonates admitted to the NICU, born at less than 32 weeks' gestational age (GA) have been enrolled. Patients who develop BPD were enrolled as cases, patients without BPD as controls. BPD was defined as need for oxygen supplementation for at least 28 days. Urine sample was collected within 48 hours of life for each patient and untargeted metabolic analysis was performed with ultra performance liquid chromatography system coupled to a Quadrupole Time-of-Flight mass spectrometer.
Results: 161 neonates have been enrolled, of that 69 with BPD (42.9%) and 92 without BPD (57.1%). The median GA at birth was 29 (27-31) weeks and the median birth weight 1115 (800-1400) g. Urine untargeted metabolomic revealed a metabolites clustering in BPD neonates in comparison to neonates without BPD. The metabolomic derangements concerned metabolites belonging to the acylcarnitine class, uridine and pseudouridine. To control the effect GA on metabolome, 11 infants with BPD were matched with 11 without BPD of comparable GA. After adjusting the analysis for GA, the main discriminating metabolites were: L-cystathionine, isovalerylcarnitine, creatine, p-hydroxyphenylacetic acid. Compared to clinical data alone, the application of urinary metabolome analysis at birth increases the sensitivity and specificity in the prediction of BPD, respectively from 86.7% to 90.0% and from 84.0% to 86.0%.
Conclusions: The metabolomic approach on urine collected within 48 hours of life revealed an interesting clustering of metabolites that discriminates between preterm infants at risk of developing BPD versus infants who will not develop it. The analysis of the identified metabolites at birth increases the prediction of BPD development in preterm infants. In the next future, early detection of infants at risk of developing BPD may be useful for the administration of targeted therapies
Interaction between Copper Oxide Nanoparticles and Amino Acids: Influence on the Antibacterial Activity
No full textThe increasing concern about antibiotic-resistance has led to the search for alternative antimicrobial agents. In this effort, different metal oxide nanomaterials are currently under investigation, in order to assess their effectiveness, safety and mode of action. This study focused on CuO nanoparticles (CuO NPs) and was aimed at evaluating how the properties and the antimicrobial activity of these nanomaterials may be affected by the interaction with ligands present in biological and environmental media. Ligands can attach to the surface of particles and/or contribute to their dissolution through ligand-assisted ion release and the formation of complexes with copper ions. Eight natural amino acids (L-Arg, L-Asp, L-Glu, L-Cys, L-Val, L-Leu, L-Phe, L-Tyr) were chosen as model molecules to investigate these interactions and the toxicity of the obtained materials against the Gram-positive bacterium Staphylococcus epidermidis ATCC 35984. A different behavior from pristine CuO NPs was observed, depending on the aminoacidic side chain. These results were supported by physico-chemical and colloidal characterization carried out by means of Fourier-Transform Infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermo-Gravimetric Analysis (TGA), Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and light scattering techniques (Dynamic Light Scattering (DLS), Electrophoretic Light Scattering (ELS) and Centrifugal Separation Analysis (CSA)
Early prediction of bronchopulmonary dysplasia by urinary metabolomics: a case–control study
No full textObjective Bronchopulmonary dysplasia (BPD), the most frequent complication of extreme preterm birth, lacks not only of a comprehensive definition but also of effective treatments and predictive tools. Metabolomics is a valuable tool to unravel the underlying pathogenetic pathways of diseases and identify possible early markers. The objective of this study was to find metabolic signatures of subsequent BPD development, defined and stratified as per Jobe and Bancalari 2001 NHICD Consensus.Methods In this observational case-control study, we initially enrolled 161 very preterm unmatched infants, collected their urine samples during the first 24 hours of life and performed metabolomics evaluations on these samples. Patients were then followed until 36 weeks postmenstrual age. To reduce the influence of gestational age and other confounders on metabolome, we applied a nested case-control matching procedure that allowed the selection of 25 BPD cases and 25 non-BPD controls.Results Multivariate and univariate data analysis led to the recognition of 17 metabolites related to BPD development in the first day of life, of which three were identified: L-Glutamic acid (p value=0.038), o-Hydroxyphenylacetic acid (p=0.039), L-Homoserine (p value=0.020). Some of these metabolites are known to play a role in the protection against oxidative stress and/or inflammatory response, two of the most known factors involved in BPD pathogenesis. In particular, L-Glutamic acid and its ionic form glutamate were increased in infants developing BPD suggesting a role as promising marker of the disease.Conclusions Our findings pave the way to better characterise early origin of BPD from a metabolic point of view towards a better biological framework of the disease and, eventually, its prediction and possible new treatments
Reflexões impostas pela pandemia do novo coronavírus. Sairemos melhor dela?
No full textBook review:Sobrinho, L. L. P; Calgaro, C.; Rocha, L. S. (Orgs.). COVID-19 e seus paradoxos. Dados eletrônicos Itajaí, SC: UNIVALI, 2020. 424 p. (E-book).Resenha do livro:Sobrinho, L. L. P; Calgaro, C.; Rocha, L. S. (Orgs.). COVID-19 e seus paradoxos. Dados eletrônicos Itajaí, SC: UNIVALI, 2020. 424 p. (E-book)
Catalitic chemical fixation of CO2 through syntehsis of acrylic monomers
No full textThe effects of CO2 emissions on global climate are well known and studied problems. Many ways of limiting such emissions have been suggested, from the injection in exhausted oil fields, to the chemical fixation of carbon dioxide in more stable forms. Among the several routes proposed, the use of carbon dioxide as a raw material in the green synthesis of strategic chemicals has gained a great interest.
From an industrial point of view, an interesting target is represented by the synthesis of acrylate using CO2 and ethene. Several transition-metals have been showed catalytic activity in such reaction in particular under controlled basic conditions.
As in the literature it is reported that the reaction of CO2 with ethene to acrylates is catalyzed by Ni(0)-phosphine complexes, in the present work we have been studied the catalytic activity of a series of Ni(II) and Pd(II) diphosphine-complexes
Irrigação de cebola por gotejamento na superfície do solo e subterrâneo.
No full textRealizou-se, no Campo Experimental de Bebedouro, pertencente à Embrapa Semiárido, em Petrolina, PE, um estudo com o objetivo de avaliar a produção de cebola, cultivar IPA 11, irrigada por gotejamento com tubos gotejadores dispostos na superfície do solo ou enterrados a 0,20 metros de profundidade. O espaçamento entre gotejadores foi de 0,30 metros, vazão do emissor de l Lh-1. O delineamento estatístico foi fatorial (2x3), blocos ao acaso, sendo duas formas de disposição de linhas laterais e número de linhas laterais por canteiro (2, 3 e 4 linhas laterais por canteiro), com cinco repetições, totalizando 30 parcelas. A dimensão da parcela foi de 1,10 metro de largura por 5,0 metros de comprimento. O espaçamento entre fileiras de plantas no canteiro foi 0,10 m e, entre plantas na fileira, de 0,15 m. O cálculo da lâmina de água foi realizado com base na evaporação da água do tanque classe A e coeficiente de cultivo da cultura. O cálculo das doses de N, P e K foi baseado na análise de solo. Aplicaram-se: 156 kg ha-1 de ureia, 150 kg ha-1 de MAP, 80 kg ha-1 de cloreto de potássio. O nitrogênio foi aplicado junto com o potássio, três vezes por semana, via água de irrigação, utilizando-se um injetor de fertilizante tipo venturi. A fertirrigação iniciou três dias após o transplantio e se estendeu por 70 dias. O fósforo foi aplicado em fundação, antes do plantio. O consumo de água foi de 3.760 m3 ha-1. O rendimento médio obtido foi de 27,31; 35,88 e 32,67 t ha-1 com tubos gotejadores na superfície do solo, com 2, 3 e 4 linhas laterais por canteiro, respectivamente. Para linhas laterais subterrâneas, o rendimento foi 20,17; 28,38 e 31,42 t ha-1 com 2, 3 e 4 linhas laterais por canteiro, respectivamente. Recomenda-se, para a cultura da cebola, o sistema de irrigação por gotejamento com três linhas laterais por canteiro, dispostas na superfície do solo. O sistema de irrigação por gotejamento subterrâneo com linhas laterais mostrou-se contra indicado para a cultura da cebola
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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