Showing papers by "Universidade Federal de Viçosa published in 2023"

One-pot tandem synthesis of 5-ethoxymethylfurfural as a potential biofuel

Abstract: 5-Ethoxymethylfurfural (EMF) is a potential biofuel, fuel additive and raw material in the chemical and beverage industry.

Carbon-Dots Based Sensors for Detection of Pollutants from Soil

Abstract: Soil is one of the compartments of the earth and is essential for the maintenance of life on the planet. Through it, the necessary nutrients are provided for the development of plants, which in addition to producing oxygen on Earth, provide food. However, with the accelerated growth of the world population, it is necessary to manage the soil for the cultivation of crops, in addition to the intensive use of pesticides. These substances can percolate into the soil, contaminating groundwater. Another problem is the use of veterinary drugs for disease control or use as supplements in animals intended for human consumption. Such animals excrete their waste directly into the soil, containing residues of such substances. In addition to being able to infiltrate the soil, they can be carried to different parts by ditches and streams. Mining practices, in turn, consist of soil contamination by metals. Many of these metals are toxic and bioaccumulative. The dynamics of pollutants in the soil depends on their physicochemical characteristics. Many of these substances are poorly sorbed and can infiltrate into the soil, contaminating groundwater, reaching surface waters and seas. Therefore, efficient methods for detection of these compounds in soil are needed. There are different analytical techniques for detection and quantification of these compounds in complex matrices such as soil. However, such methods are expensive, require highly trained technicians, equipment maintenance is expensive, and sample preparation is labor intensive and costly. Thus, the use of Carbon-Dots (C-Dots) produced by green synthesis can be a very promising alternative, which provides very reliable results. The processes are simple and cheaper compared to specific instrumental methods. Therefore, in this chapter will be described the (1) characteristics of the soil, which allow the interaction and sorption of a certain pollutant; (2) a brief description of the main soil pollutants; (3) an approach to carbonaceous materials, specifically about Carbon-Dots and finally, (4) an approach about the detection of soil pollutants by Carbon-Dots. The information described in this chapter can help professionals in different areas such as chemistry, materials science, engineering (chemical, environmental, agricultural, etc.), agronomy, biology, physics, among others.

Relationship between dietary macronutrient composition with weight loss after bariatric surgery: A systematic review

Abstract: This systematic review evaluated the relationship between macronutrient intake and weight loss after bariatric surgery (BS). The MEDLINE/Pubmed, EMBASE, COCHRANE/CENTRAL, and SCOPUS databases were accessed in August 2021 to search for eligible articles: original publications with adults undergoing BS and indicating the relationship between macronutrients and weight loss. Titles that did not meet these criteria were excluded. The review was written according to the PRISMA guide, and the risk of bias was according to the Joanna Briggs manual. Data were extracted by one reviewer and checked by another. Eight articles with 2.378 subjects were included. The studies indicated a positive relationship between weight loss and protein intake after BS. Prioritization of protein followed by carbohydrates with a lower percentage of lipids favors weight loss and increases weight stability after BS. Among the results found, a 1% increase in protein intake raises the probability of obesity remission by 6%, and high-protein diet increase 50% weight loss success. Limitations are the methods of included studies and review process. It is concluded that high-protein intake >60 g a 90 g/day may favor weight loss and maintenance after BS, but it is relevant to balance the other macronutrients.

Iterated Local Search Heuristic for Integrated Single Machine Scheduling and Vehicle Routing

Abstract: In this paper we address a problem that integrates the single machine scheduling problem and the vehicle routing problem. In this problem, N jobs must be executed on a machine, and, using a set of vehicles, the jobs must be delivered to the respective customers. The objective of the problem is to determine the sequencing of jobs on the machine and the routes of the vehicles, in order to minimize the total fixed costs, the total travel costs of vehicles and the total weighted tardiness of the jobs. To solve the problem, initially a mixed integer linear programming model is proposed. Motivated by the computational complexity of the problem, two hybrid heuristics based on the iterated local search (ILS) and random variable neighborhood descent (RVND) metaheuristics are proposed. The performances of the proposed heuristics are evaluated and compared on a set of instances randomly generated. The results show that one of the proposed heuristics has a superior performance, as can be seen through the comparison with a genetic algorithm from the literature. In average, the solutions obtained by our heuristic were within 0.67% of the best known solutions.

Evaluating feline lower urinary tract disease: Doppler ultrasound of the kidneys

Abstract: Objectives Ultrasonography is used in the evaluation of urinary disorders, and the resistivity index (RI) and pulsatility index (PI) have been successfully used to detect early hemodynamic changes in the course of kidney diseases in humans and dogs. The aim of this study was to investigate RI and PI in cats with feline lower urinary tract disease (FLUTD). Methods Twenty-nine client-owned cats were selected and divided into a control group (CG; n = 10), a group of animals with obstructive FLUTD (OG; n = 11) and non-obstructive FLUTD (nOG; n = 8). Clinical, laboratory and ultrasound evaluations were performed in all cats. Results RI and PI values for cats in the CG were below the upper limit of normal suggested in other studies, while cats with FLUTD showed significantly higher values in the assessment of RI ( P = 0.027 and P = 0.034, respectively) and PI ( P = 0.044 and P = 0.048, respectively) of the right and left kidneys. Conclusions and relevance Alteration in renal blood flow was observed in cats with lower urinary tract disorders, even in the nOG group. To the best of our knowledge, this is the first report of renal blood flow changes related to non-obstructive FLUTD.

As Flutuações de Longo Prazo da Polarização no Brasil – Análise do Compartilhamento de Informações Políticas Entre 2011 e 2019

Abstract: RESUMO A literatura especializada sobre polarização da circulação de informações políticas nas mídias digitais vem apontando uma segregação estrutural entre o consumo de notícias no espectro ideológico. Esses achados suportam a ideia de filtros-bolha relativamente estáveis que encapsulam a visão do mundo político. Essa pesquisa questiona se esses padrões se mantêm no longo prazo ou são condicionados por momentos de alta tensão, como eleições nacionais. Para isso, investiga quantitativamente os links citados em 7,7 milhões de publicações feitas no Facebook, entre 2011 e 2019, por páginas organizadas, por técnicas de análise de redes sociais, em clusters de esquerda e de direita. Os resultados enfatizam dinâmicas de polarização que não são estanques, mas flutuam de acordo com as configurações do sistema político. A principal contribuição desse artigo é demonstrar nuances da polarização, identificando não necessariamente polos segregados, mas fatores temporais, políticos e midiáticos que estimulam e arrefecem a insularidade informacional.

Changes to virus taxonomy and the ICTV Statutes ratified by the International Committee on Taxonomy of Viruses (2023)

Abstract: This article reports changes to virus taxonomy and taxon nomenclature that were approved and ratified by the International Committee on Taxonomy of Viruses (ICTV) in April 2023. The entire ICTV membership was invited to vote on 174 taxonomic proposals that had been approved by the ICTV Executive Committee in July 2022, as well as a proposed revision of the ICTV Statutes. All proposals and the revised ICTV Statutes were approved by a majority of the voting membership. Of note, the ICTV continued the process of renaming existing species in accordance with the recently mandated binomial format and included gene transfer agents (GTAs) in the classification framework by classifying them as viriforms. In total, one class, seven orders, 31 families, 214 genera, and 858 species were created.

Effects of calcium chloride substitution on the physicochemical properties of Minas Frescal cheese

Abstract: The aim in this research paper was to investigate the effect of using calcium monophosphate (MCP) and MCP mixed with commercial phosphates salts, in total or partial replacement of calcium chloride (CaCl2) in the manufacture of Minas Frescal cheese. Initially, model cheeses were made to perform the rheological analysis during the coagulation process. Of these, the five best treatments were chosen to carry out the production of Minas Frescal cheese, used only CaCl2 and MCP, and partial replacements of MCP + polyphosphate, MCP + potassium monophosphate (MKP) and MCP. The cheeses showed no significant difference in physicochemical composition, yield and syneresis, however, the cheese with partial replacement of CaCl2 by MCP + polyphosphate and MCP + MKP showed the highest hardness values, like the control. This demonstrates that it is possible to replace calcium chloride without significant changes in the physicochemical characteristics and yield of Minas Frescal cheese, and it is still possible to modulate the hardness of the cheese produced according to the type of calcium/phosphate source used. This allows the industry to replace the source of calcium in the manufacture of Minas Frescal cheese according to the desired hardness.