Search results for "Acid"
showing 10 items of 13107 documents
Gestión de proyectos: antecedentes y consecuentes en el contexto del proyecto y de la organización
2020
En los entornos actuales, caracterizados por altos niveles de competitividad e incertidumbre, las organizaciones se han enfocado en desarrollar sus actividades a través de proyectos, orientados al logro de los objetivos estratégicos. La gestión de proyectos [Project Management (PM)], se refiere a la aplicación de conocimientos, habilidades, herramientas, técnicas, métodos y competencias, a las actividades de los proyectos, con el objetivo alcanzar el éxito en el desempeño de los mismos. En este sentido, la PM, ha adquirido una alta relevancia, por el impacto que genera en la competitividad de las empresas y en el desarrollo económico de los países. A nivel científico, se han logrado avances…
Screening of lactic acid bacteria for their use as aromatic starters during fermentation of vegetables
2020
Lactic acid bacteria (LAB) have good growth capacities on various food matrices and produce very diverse enzymatic activities which are notably capable of positively modifying the organoleptic properties of fermented foods. Therefore, the selection of the LAB starters possessing good metabolic abilities and interesting enzymatic activities towards the plant matrix could improve the aroma profiles of fermented foods. The main objective of this study was to enhance the aroma profiles of fermented tomatoes by using the biotechnological pathway. To achieve this, firstly, 200 LAB isolated from Cambodian and Vietnamese fermented foods were screened for their β-glucosidase activity and duplicate i…
ISomerization of xylene: MINDO/3 study of the cyclization of benzenium cation into bicyclo[3.1.0]hexenyl cation
1989
Abstract A MINDO/3 study of thermal electrocyclic closing of the benzenium cation to form a bicyclo[3.1.0]hexenyl cation is presented. The calculated mechanism discusses the possibility of cyclization of xylenium cations on a silica catalyst or in superacid media. The structure and energy of the transition state, the enthalpies of isomerization and barriers of activation were calculated for the following processes: isomerization of 2,6-dimethylbenzenium cation into 2,6-dimethylbicyclo[3.1.0]hexenyl cation, isomerization of 2,4-dimethylbenzenium cation into 2,4-dimethylbicyclo[3.1.0]-hexenyl cation, and isomerization of benzenium cation into bicyclo[3.1.0]-hexenyl cation. Equilibrium and kin…
Metal ion-promoted activation of amino acid esters of carbohydrates in the synthesis of peptides
1992
Abstract Carbohydrate esters 1 and 2 of N-protected amino acids are activated by coordination of metal ions and subjected to aminolysis by amino acid esters 3 to form peptides 4 .
A solution study of complex formation between iron(III) and oxalate in dimethylsulphoxide
1991
The complex formation between iron(III) and oxalic acid (ethanedioic acid, H2ox) has been studied by potentiometry in dimethylsulphoxide (dmso) solution. H2ox behaves as a weak diprotic acid in such a solvent, with overall association constants: log βj1=8.551(3) and log βj2=14.242(3) at 25°C and 0.1 Mn-Bu4NClO4. A reliable set of overall stability constants for the iron(III)-oxalato complexes, log β11=13.16(4), log β12=23.66(4) and log β13=30.75(4), have been obtained for the first time under identical conditions. The electrochemical behaviour of such complexes was studied in dmso at a platinum electrode. The coordination ability of oxalate towards iron(III) in dmso and water media is compa…
Thin-layer chromatography of phenoxyacetic acid herbicides
1981
Intestinal conversion of linoleic acid to arachidonic acid in the rat
1993
Abstract The arachidonic acid (C20:4, n-6) appearing in intestinal lymph during linoleic acid (C18:2, n-6) absorption may originate from enterocyte synthesis or from the liver either after secretion in biliary phospholipids at the same time dietary linoleic acid absorption occurs or via plasma. The radioactivity measured in the total bile collected during the 6 hours of linoleic acid absorption is too small to explain hepatic origin of the C20:4 detected by high performance liquid chromatography analysis of labeled fatty acids recovered in the lymph, in the intestinal mucosa, and the intestinal wall at the peak of linoleic acid intestinal absorption. This study confirms the probability that…
Adaptative biochemical pathways and regulatory networks in Klebsiella oxytoca BAS-10 producing a biotechnologically relevant exopolysaccharide during…
2012
Abstract Background A bacterial strain previously isolated from pyrite mine drainage and named BAS-10 was tentatively identified as Klebsiella oxytoca. Unlikely other enterobacteria, BAS-10 is able to grow on Fe(III)-citrate as sole carbon and energy source, yielding acetic acid and CO2 coupled with Fe(III) reduction to Fe(II) and showing unusual physiological characteristics. In fact, under this growth condition, BAS-10 produces an exopolysaccharide (EPS) having a high rhamnose content and metal-binding properties, whose biotechnological applications were proven as very relevant. Results Further phylogenetic analysis, based on 16S rDNA sequence, definitively confirmed that BAS-10 belongs t…
Differential diurnal variations of anandamide and 2-arachidonoyl-glycerol levels in rat brain.
2004
The endogenous ligands of cannabinoid receptors, also known as endocannabinoids, have been implicated in many physiological and pathological processes of the central nervous system. Here we show that the levels of the two major endocannabinoids, anandamide and 2-arachidonoyl-glycerol (2-AG), in four areas of the rat brain, change dramatically between the light and dark phases of the day. While anandamide levels in the nucleus accumbens, pre-frontal cortex, striatum and hippocampus were significantly higher in the dark phase, the opposite was observed with 2-AG, whose levels were significantly higher during the light phase in all four regions. We found that the activity of the fatty acid ami…
Crystal structure of bis(cyclohexylammonium) diphenyldioxalatostannate(IV)
2015
In the title salt, (CyNH3)2[Sn(Ph2)(C2O4)2] (Cy is cyclohexyl and Ph is phenyl), the SnPh2 moiety is chelated by two oxalate anions, leading to a cis arrangement within the distorted octahedral coordination sphere of the SnIV atom.