Publications by authors named "Maximo F"

The value of branched esters comes from the special properties they have in cold environments, which allow them to remain liquid over a wide range of temperatures. These properties make them useful for application in the cosmetic industry or as lubricant additives. This paper presents the studies carried out to ascertain the operational feasibility of the enzymatic esterification of 2-methylpentanoic acid (MPA) with 1,10-decanediol (DD), with the objective of obtaining a novel molecule: decane-1,10-diyl bis(2-methylpentanoate) (DDBMP).

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The aim of this study was to evaluate in vivo dental biofilm acidogenicity induced by nine long-term pediatric oral liquid medications (OLMs). A double-blind crossover randomized clinical trial was conducted with 12 individuals aged 18 to 22 years who had good oral hygiene (OSI < 1.1) and a DMFT index of less than 12.

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Esters are versatile compounds with a wide range of applications in various industries due to their unique properties and pleasant aromas. Conventionally, the manufacture of these compounds has relied on the chemical route. Nevertheless, this technique employs high temperatures and inorganic catalysts, resulting in undesired additional steps to purify the final product by removing solvent residues, which decreases environmental sustainability and energy efficiency.

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Biocatalytic synthesis of 2-ethylhexyl 2-methylhexanoate is described in this work for the first time. This branched-chain ester is suitable for use at low temperatures in numerous applications. The immobilized lipase Novozym 435 has demonstrated its ability to catalyze the ester synthesis from 2-ethylhexanol and 2-methylhexanoic acid in a solvent-free medium.

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SARS-CoV-2 has spread rapidly around the world, with Brazil currently considered an epicenter of the pandemic. The Northern region has the second highest incidence coefficient, as well as the third highest mortality rate in the country. This study aimed to investigate information about the evolutionary history of epidemic spread and genetic aspects of strains isolated on the Western Amazon, in the State of Rondônia, Brazil.

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Introduction: Coronavirus disease-2019 (COVID-19) is a disease caused by Severe Acute Respiratory Syndrome Virus 2 (SARS-CoV-2) that emerged in China in late 2019. The rapid viral spread has made the disease a public health emergency of worldwide concern. The gold standard for diagnosing SARS-CoV-2 is reverse transcription followed by qualitative real-time polymerase chain reaction (RT-qPCR); however, the role of viral load quantification has not been thoroughly investigated yet.

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Esters from branched alcohols and dicarboxylic linear acids are widely used as lube bases due to their good performance at low temperatures. This work proposes a new process to synthesize bis(2-ethylbutyl) adipate and bis(2-ethylbutyl) sebacate by using the lipase-based catalyst Novozym® 435 in a solvent-free system. Different reaction strategies have been tested in order to minimize 2-ethyl-1-butanol losses due to its evaporation and optimum operation conditions have been determined: 2.

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This work describes for the first time the green synthesis of neopentyl glycol diheptanoate in a solvent-free medium via an enzymatic pathway. The process has been carried out in an open-air reactor in order to ease water removal through evaporation and shift the chemical equilibrium towards product formation. The inhibiting effect of high concentrations of heptanoic acid has been put into evidence by a reduction of initial reaction rate when esterification was performed with stoichiometric amounts of substrates.

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During the past decades the understanding and prospects of enzyme-catalysed reactions have been massively widened and there are a number of implemented large-scale enzymatic processes mainly based in the use of commercial biocatalysts. As it might happen that the same process can be successfully carried out by different commercial lipases, the election of the biocatalyst must rely on productivity and economic considerations. This work presents productiveness and direct operation cost evaluation as a key tool for the selection between two commercial lipase catalysts, the versatile but expensive Novozym 435 and a much more economical option, Lipozyme TL IM, in the synthesis of spermaceti, a mixture of emollient esters with cosmetic applications.

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Silicones are polymers that have properties of great interest for cosmetic and personal care industry, especially D (octamethylcyclotetrasiloxane) and D (decamethylcyclopentasiloxane), generically named cyclomethicones. However, different studies show the hypothesis that the use of these products is harmful and, therefore, several countries have adopted legislative actions to limit their use in personal care and cosmetic products. Faced with this new situation, different cosmetic companies began to look for different alternatives to cyclomethicones, mainly: organomodified silicones or esters.

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Purpose: The ability to measure oxidative DNA damage in a tissue allows establishment of the relationship between DNA damage and mutations in normal and neoplastic cells. It is well known that TP53 is a key inhibitor of tumor development and preserves the genome integrity in each cell. The aim of the present study was to investigate the relationship between DNA damage and TP53 mutation in colorectal adenoma and adenocarcinoma, and the value of DNA damage as potential marker of TP53 mutation in non-tumor tissues adjacent to colon malignant lesions.

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Background: Different strategies for the solvent-free enzymatic production of polyglycerol polyricinoleate (PGPR) were explored in an attempt to simplify and improve the process. Besides the conventional procedure (obtaining polyricinoleic acid, followed by its esterification with polyglycerol), two alternative methods are proposed: (1) reversing the synthesis order, i.e.

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Background: No studies have evaluated the effectiveness of 5-ASA against oxidative DNA damage in experimental models of diversion colitis.

Aim: To evaluate the effects of 5-ASA against oxidative DNA damage in an experimental model of diversion colitis.

Methods: Twenty-six Wistar rats were divided into two groups corresponding to sacrifice at 2 or 4 weeks after fecal diversion of the left colon by means of proximal colostomy and distal mucosa fistula.

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Purpose: To quantify the intensity of sulfomucin and sialomucin expression in the colon mucosa, by means of computer-assisted image processing, comparing segments with and without fecal stream and correlating with the duration of fecal transit exclusion.

Methods: Forty-five Wistar rats were subjected to diversion of the fecal stream in the left colon by means of constructing a proximal colostomy and distal mucosal fistula. They were distributed randomly into three experimental groups of 15 animals, of which 10 were subjected to colon diversion (experimental subgroup) and five were only subjected to laparotomy, without colon diversion (control subgroup).

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Purpose: To quantify the intensity of the expression of neutral and acids mucins in mucosa of the colon with and without fecal stream and to correlate this with the duration of fecal transit diversion.

Methods: Thirty male Wistar rats were subjected to fecal transit deviation in the left colon by a proximal colostomy and a distal mucous fistula. The animals were divided into three experimental groups, according to whether sacrificing would be performed six, 12 or 18 weeks after surgery.

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Context: Epithelioid hemangioma or angiolymphoid hyperplasia with eosinophilia is an uncommon benign vascular neoplasm that is usually located on the face or neck. Exceptionally, it has been described affecting the colon, with only two such cases described in the worldwide literature. The aim here was to present a case of primary epithelioid hemangioma of the sigmoid colon with confirmation by immunohistochemical examination.

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