Stationary
Mostrando 1-12 de 3118 artigos, teses e dissertações.
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1. Per-Aqueous Liquid Chromatography for the Separation of Polar Compounds Preparation and Characterization of Poly(ethylene oxide co dimethylsiloxane) Based Stationary Phase
Poly(ethylene oxide-co-dimethylsiloxane) was thermally immobilized on silica particles-Si(PEO)-to separate small polar compounds with water-rich mobile phases. Poly(ethylene oxide-co-dimethylsiloxane) content on Si(PEO) stationary phase was optimized using a central composite design. Infrared spectroscopy, scanning electron microscopy, and thermogravimetric
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Short-term mine scheduling targeting stationary grades
Abstract In short-term mine planning, mining scheduling is generally defined by designing dig-lines, allocated on benches. The mined ore will be sent to stockpiles, homogenization piles, or a concentration plant. The process to design dig-lines is usually done manually, whereby multiple simultaneous mining fronts are time-consuming and labour-intensive. The
REM - International Engineering Journal. Publicado em: 2022
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3. FGF23 levels as a marker of physical performance and falls in community-dwelling very old individuals
ABSTRACT Objective: The fibroblast growth factor 23 (FGF23) has been related to biological aging, but data in elderly individuals are scant. We determined the profile of serum FGF23 levels in a population of very-old individuals and studied their correlations with parameters of bone metabolism and health markers, as functional performance. Materials and me
Archives of Endocrinology and Metabolism. Publicado em: 2022
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4. Development and application of a test mixture for untargeted liquid chromatography-mass spectrometry analysis of urine samples
Metabolic profiling of complex biological matrices based on liquid chromatography-mass spectrometry (LC-MS) allows detecting a wide range of metabolites with distinct concentrations and physicochemical properties. Given the complexity of samples and the necessity of a comprehensive approach in untargeted metabolomics, quality control strategies are mandatory
Química Nova. Publicado em: 2022
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5. A Model of Social Distancing for Interacting Age-Distributed Multi-Populations: An Analysis of Students’ In-Person Return to Schools
ABSTRACT Because of the current scenario of the SARS-CoV-2 (COVID-19) pandemic in Brazil, whose vaccination campaign is in its initial stage, government authorities have pointed towards the complete reopening of the economy. And recently, for the in-personal return of classroom teaching in schools. Given the family relationship, one of the questions that rem
Trends in Computational and Applied Mathematics. Publicado em: 2022
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6. Blood donor candidates and blood donations performed between 2005 and 2019 in Minas Gerais, Brazil: A time series analysis.
ABSTRACT Introduction: Time series studies related to blood donor candidates and blood donations are rare in Brazil. Population aging suggests a better understanding of the context related to blood donor candidates and blood donations performed. Objective: The monthly series of candidates eligible to donate blood and actual donations between 2005 and 2019
Hematology, Transfusion and Cell Therapy. Publicado em: 2022
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7. Analysis of the trend of hospitalizations for asthma in children and adolescents in Brazil
Abstract Objective To analyze the trend of hospitalizations for asthma in children and adolescents by region and age group in Brazil, from 2008 to 2017. Method This is a time-series study with secondary data regarding hospitalizations for asthma in children and adolescents, according to age, region, and gender. Descriptive statistics procedures were used w
J. Pediatr. (Rio J.). Publicado em: 2021-06
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8. Conservative Treatment of Unicuspid Aortic Valve with Newly Diagnosed Type A Aortic Dissection
Abstract We present a case of a 36-year-old male patient with known arthrogryposis multiplex congenita and an associated unicuspid aortic valve. The patient later developed a significant aneurysm of the ascending aorta, however refused surgical intervention and missed follow-up appointments for 5 years. During an urgent, general practitioner-initiated transt
Braz. J. Cardiovasc. Surg.. Publicado em: 2020-12
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9. Leprosy in Brazil in the 21st century: analysis of epidemiological and operational indicators using inflection point regression,
Abstract The objective of this study was to analyze the trend of epidemiological and operational indicators of leprosy in Brazil, from 2001 to 2017. This was a time series study involving nine indicators. The inflection point regression model was used. Decreasing trends were observed for the following: general detection (−4.8%), children under 15 (−3.7%)
An. Bras. Dermatol.. Publicado em: 2020-12
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10. HPLC METHOD IMPROVEMENT FOR 4-NONYLPHENOL DETERMINATION IN ANAEROBIC REACTORS: DECREASING SOLVENT CONSUMPTION AND WASTE GENERATION
The aim of this study was to develop a chromatographic method for 4-NP determination in anaerobic batch reactors using low amount of organic solvents and also evaluate 4-NP degradation in the presence of different co-substrates. Chromatographic parameters was improved for stationary phase (C-8 column), mobile phase (acetonitrile/water solution 90:10, v:v), c
Quím. Nova. Publicado em: 2020-09
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11. CONSTRUÇÃO DE MINI FORNO PARA FUNCIONALIZAÇÃO TÉRMICA DE FASES ESTACIONÁRIAS MONOLÍTICAS
The present work describes a mini oven built to be applied in the preparation of monolithic stationary phase through the thermal polymerization approach. The developed device was successfully tested for functionalization of monolithic stationary phase in the internal surface of the silica capillary column fused with gold nanoparticles.
Quím. Nova. Publicado em: 2020-03
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12. AVALIAÇÃO DE ADITIVOS DE FASE MÓVEL E TEMPERATURA NA VIDA ÚTIL DE COLUNAS PARA CROMATOGRAFIA LÍQUIDA DE ALTA EFICIÊNCIA
Buffered solutions, additives, and column temperature are widely used in high-performance liquid chromatography to promote adequate retention of compounds and to improve the chromatographic separation. However, these factors can dramatically reduce the column lifetime. In this work, the effect of column temperature, pH and the salt type and concentration in
Quím. Nova. Publicado em: 2020-03