780 research outputs found
Kinetics and Mechanism of Hydrolysis of Benzimidazolylcarbamates
Synthesis of new 2-aminobenzimidazole-1-carbamates was accomplished by carbamoylation of 2-aminobenzimidazole using different substituted phenyl chloroformates.
The aqueous hydrolysis of the new compounds was examined in the pH range 1-13 at 25 oC. The evaluated kinetic parameters led to the conclusion that up to pH 4 reaction proceeds by a bimolecular attack of water to the N-protonated substrate. This is the first time this behavior
is described for carbamates, and can be ascribed to the higher basicity of the benzimidazolyl moiety when compared with the carbonyl oxygen. For higher values of pH, the results are consistent with a BAc2 mechanism with nucleophilic catalysis, but while between pH 4 and pH 7 water acts as the nucleophile, for pH> 7 the hydroxide ion is the acting species
Predictors for weight loss failure following roux-en-y gastric bypass
Weight loss failure is a widely recognized occurrence following Roux-en-Y gastric bypass. This study aims to identify predictors associated with weight loss failure. It is a retrospective cohort which enrolled 187 subjects who underwent RYGB. Comparisons were made between patients' features at baseline and 24 months after surgery. A weight loss failure rate of 11.2% was found. Advanced age and diabetes were statistically associated with failure. The results found were close to previous reports. As weight loss failure represents an important concern, there is the possibility to perform revisional surgeries, which may emphasize the restrictive or malabsorptive characteristics of RYGB, leading to varied results. It is reinforced that weight loss cannot be used as the unique outcome to evaluate the success of surgery.Weight loss failure is a widely recognized occurrence following Roux-en-Y gastric bypass. This study aims to identify predictors associated with weight loss failure. It is a retrospective cohort which enrolled 187 subjects who underwent RYGB. Comparisons514328330sem informaçãosem informaçã
Estudo do nível de desenvolvimento da coordenação motora da população escolar (6 a 10 anos de idade) da região autónoma dos Açores
Os propósitos da presente investigação foram: (1) caracterizar o estado de desenvolvimento da coordenação motora ao longo dos quatro anos do 1º ciclo do ensino básico (1CEB); (2) mapear as diferenças entre as crianças dos dois sexos; e (3)
identificar a presença de insuficiência de desenvolvimento coordenativo. A amostra foi constituída por 3742 crianças de ambos os sexos dos 6 aos 10 anos de idade a frequentar o 1CEB na Região Autónoma dos Açores. A coordenação foi avaliada através
da bateria de testes de coordenação corporal
(Körperkoordinationstest für Kinder - KTK) que é composta por quatro testes: (1) equilíbrio em marcha à retaguarda (ER);(2) saltos laterais (SL);(3)saltos monopedais (SM); e(4)transposição lateral (TL). A partir do resultado de cada teste, e
através da utilização das tabelas de valores normativos fornecidas pelo manual, obtém-se um quociente motor (QM). Fez-se a análise teste a teste e ao QM. Para além das medidas descritivas (média e desvio-padrão), recorreu-se à ANOVA factorial para identificar diferenças entre os sexos ao longo da idade, e utilizou-se a função discriminante para testar a presença de
perfis multivariados de coordenação motora. Verificou-se que, em ambos os sexos e em todas as provas da bateria, ocorre um
incremento significativo dos valores médios de cada teste ao longo da idade, tendo os meninos valores médios superiores aos das meninas em todos os intervalos etários em todos os itens da bateria, com a excepção dos SL. Os valores médios do desempenho nas quatro provas são inferiores aos valores
médios obtidos noutros estudos realizados, quer em Portugal, quer no estrangeiro. Contrariamente ao esperado, os valores
médios do QM decrescem com a idade. A generalidade das crianças, em ambos os sexos e nos diferentes intervalos etários,
situa-se no intervalo de insuficiência coordenativa e de perturbações de coordenação. Constata-se, em ambos os sexos, a tendência generalizada para as crianças de uma idade mostrarem perfis de coordenação motora inferiores àqueles que são esperados
para a sua idade. Tal circunstância revela uma forte insuficiência em aspectos do desenvolvimento coordenativo nas diferentes idades
Real-time tourists counting and tracking system for management of nature trails in naturtejo global geopark (Portugal)
This paper presents a counting system project for the Naturtejo Global Geopark, which is structured in two phases. The objective of the first phase was to develop, install and test an electronic system able to remotely count the number of visitors on the Naturtejo Geopark walking routes and touristic sites. The data is reported through a web interface. A Pilot test is currently installed on Trail PR3 – “Fossil’s Route”, near the village of Penha Garcia. Since May 2015, more than 6000 tourists where monitored. The second phase of the project aims to track tourists based on the detection of Wi-Fi signals generated by their smartphones. Thanks to data mining algorithms, useful insights can be extracted that helps to understand the behaviour of tourists when they travel around the large territory of the Geopark.info:eu-repo/semantics/publishedVersio
Genome wide characterization of minimally differentiated acute myeloid leukemia
Minimally differentiated acute myeloid leukemia (AML-M0) occurs in 5 percent of all AML cases as has a remarkably poor prognosis. The aim of this thesis was to characterize a cohort of AML-M0 cases at the genomic and gene expression level making use of single nucleotide polymorphism (SNP) analysis and gene expression profiling, among other techniques. In short, our study contributed in establishing RUNX1 biallelic mutations as a primary event in AML-M0 and showed that homozygosity of RUNX1 mutations was associated with uniparental disomy. We also showed that ETV6 mutation occurs in a small proposition of cases and detected a broad number of RUNX1/ETV6 collaborating mutations, most of which in members of the RAS signaling pathway. In addition, the results suggest that the association between RUNX1 mutation and trisomy 13, and concomitant increased in FLT3 expression, is an alternative way of activatin g the RAS signaling pathway. Finally, gene expression profiling (GEP) showed a distinct expression for AML-M0 cases which indicates they are a distinct entity from other AML groups. GEP also showed that AML-M0 is further subdivided into two distinct subgroups. One of these subgroups was associated with RUNX1 mutations and characterized by the expression of B-lymphocyte related genes."Fundação para a Ciência e a Tecnologia (Portugal)" and "Fundação Calouste Gulbenkian (Portugal)"UBL - phd migration 201
Variabilidade nos valores de aptidão física associada à saúde e da coordenação motora: um estudo de modelação hierárquica
Este trabalho1 pretende mostrar as potencialidades da modelação hierárquica a partir de informação obtida sobre a aptidão física associada á saúde (ApFS) e coordenação motora (CMotora) de crianças do 1º ciclo do ensino básico da região autónoma dos Açores (RAA).
Quando se lida com informação proveniente de pesquisas no domínio do Desenvolvimento Motor, concretamente na ApFS e CMotora, e cujas amostras rondam as centenas ou milhares de sujeitos, é corrente pensar não só em termos de descrição exaustiva das variáveis, mas também da sua comparação ou diferenciação em função da idade, sexo ou outros critérios. Raras vezes se pensa em termos de interpretação ou atribuição de significado à variância presente nos resultados do desempenho motor das crianças
Urinary Metabolic Phenotyping Reveals Differences in the Metabolic Status of Healthy and Inflammatory Bowel Disease (IBD) Children in Relation to Growth and Disease Activity.
Growth failure and delayed puberty are well known features of children and adolescents with inflammatory bowel disease (IBD), in addition to the chronic course of the disease. Urinary metabonomics was applied in order to better understand metabolic changes between healthy and IBD children.
21 Pediatric patients with IBD (mean age 14.8 years, 8 males) were enrolled from the Pediatric Gastroenterology Outpatient Clinic over two years. Clinical and biological data were collected at baseline, 6, and 12 months. 27 healthy children (mean age 12.9 years, 16 males) were assessed at baseline. Urine samples were collected at each visit and subjected to ¹H Nuclear Magnetic Resonance (NMR) spectroscopy.
Using ¹H NMR metabonomics, we determined that urine metabolic profiles of IBD children differ significantly from healthy controls. Metabolic differences include central energy metabolism, amino acid, and gut microbial metabolic pathways. The analysis described that combined urinary urea and phenylacetylglutamine-two readouts of nitrogen metabolism-may be relevant to monitor metabolic status in the course of disease.
Non-invasive sampling of urine followed by metabonomic profiling can elucidate and monitor the metabolic status of children in relation to disease status. Further developments of omic-approaches in pediatric research might deliver novel nutritional and metabolic hypotheses
Stellar Inversion Techniques
Stellar seismic inversions have proved to be a powerful technique for probing
the internal structure of stars, and paving the way for a better understanding
of the underlying physics by revealing some of the shortcomings in current
stellar models. In this lecture, we provide an introduction to this topic by
explaining kernel-based inversion techniques. Specifically, we explain how
various kernels are obtained from the pulsation equations, and describe
inversion techniques such as the Regularised Least-Squares (RLS) and Optimally
Localised Averages (OLA) methods.Comment: 20 pages, 8 figures. Lecture presented at the IVth Azores
International Advanced School in Space Sciences on "Asteroseismology and
Exoplanets: Listening to the Stars and Searching for New Worlds"
(arXiv:1709.00645), which took place in Horta, Azores Islands, Portugal in
July 201
Estudo de niveis de populaçao de Anticarsia gemmatalis Hübner, 1818 e Plusia sp. em soja no Rio Grande do Sul
Estudos dos níveis de populaçãio de Anticarsia gemmatalis e Plosia sp. em soja no RS, indicaram que essas espécies alcançaram maior incidéncia na segunda quinzena de janeiro.
A proporção entre A. gemmatalis e Plosia sp. foi de aproximadamente 10:1. A população de A. gemmatalis e percentagem de desfolhamento aumentou rapidamente dé 18 a 26 de janeiro.
Este estudo indicou que o desaparecimento repentino ·de A. gemmatalis nos meses de fevereiro e março foi, na maior parte, devido ao ataque do fungo Nomuraea rileyi (Farlow) Samson ( = Spicaria rileyi).
Agron. Sulriograndense, Porto Alegre, 11(1):29-35, 1975
Analysis and design of a silicide-tetrahedrite thermoelectric generator concept suitable for large-scale industrial waste heat recovery
Industrial Waste Heat Recovery (IWHR) is one of the areas with strong potential for energy efficiency and emissions reductions in industry. Thermoelectric (TE) generators (TEGs) are among the few technologies that are intrinsically modular and can convert heat directly into electricity without moving parts, so they are nearly maintenance-free and can work unattended for long periods of time. However, most existing TEGs are only suitable for small-scale niche applications because they typically display a cost per unit power and a conversion efficiency that is not competitive with competing technologies, and they also tend to rely on rare and/or toxic materials. Moreover, their geometric configuration, manufacturing methods and heat exchangers are often not suitable for large-scale applications. The present analysis aims to tackle several of these challenges. A module incorporating constructive solutions suitable for upscaling, namely, using larger than usual TE elements (up to 24 mm in diameter) made from affordable p-tetrahedrite and n-magnesium silicide materials, was assessed with a multiphysics tool for conditions typical of IWHR. Geometric configurations optimized for efficiency, power per pair and power density, as well as an efficiency/power balanced solution, were extracted from these simulations. A balanced solution provided 0.62 kWe/m2 with a 3.9% efficiency. Good prospects for large-scale IWHR with TEGs are anticipated if these figures could be replicated in a real-world application and implemented with constructive solutions suitable for large-scale systems.Fundação para a Ciência e a Tecnologia, European Regional Development Fund (ERDF),
P.O.F.C.—COMPETE, European and National Funds: M-ERA.net Project THERMOSS (M-ERANET2/0011/2016), MEtRICs—Mechanical Engineering and Resource Sustainability Centre (UIDB/
04077/2020), C2TN—Center for Nuclear Sciences and Technologies (UID/Multi/04349/2019), Project
Exhaust2Energy (PTDC/EMS-ENE/3009/2014)
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