Synthesis and Characterization of Amide Stationary Phases for the Determination of Sulfonamides by Sequential Injection Chromatography

Producción CientíficaThe synthesis of amide (butyl, cyclohexyl, and phenyl) modified silica and the use as stationary phases in sequential injection chromatogra-phy are described. The system was tested on the isocratic separation of seven sulfonamides (sulfachloropyridazine, sulfadimethoxine, sulfame-thazine, sulfamethoxazole, sulfamethoxypyridazine, sulfaquinoxaline, and sulfathiazole) using each stationary phase with mobile phases composed of acetonitrile/water at a flow rate of 0.45 mL min−1. A mixed mode retention mechanism of sulfonamides in the stationary phases was obtained, including dipole-dipole, π-π, and hydrogen bonding interactions. The most appropriate phase for the separation of sulfonamides was phenylamide. The chromatographic behavior was confirmed using density functional theory of the interaction between sulfamethoxazole and the stationary phases.Junta de Castilla y León Proyecto VA171U1

Evaluación in silico de péptidos bioactivos derivados de la digestión de proteínas presentes en la leche de bovino (B. taurus), oveja (O. aries), cabra (C. hircus) y búfalo (B. bubalis)

The growing demand for food with high nutritional value has led to the replacement of bovine milk with milk from other ruminants. The protein fraction in milk is relatively constant among species and includes caseins ( S1-casein, -casein, and -casein) and whey proteins ( -lactalbumin and -lactoglobulin). Current studies into milk derived bioactive peptides focus on proteins obtained from a single species and are conducted using non-human proteases. In this paper, we make a quantitative comparison of the bioactive peptides obtained from the caseins and whey proteins present in bovine (Bos taurus), sheep (Ovis aries), goat (Capra hircus), and buffalo (Bubalus bubalis) milk. The study is carried out by in silico digestion with the following proteolytic enzymes found in the human digestive system: pepsin (EC 3.4.23.1), trypsin (EC 3.4.21.4), and chymotrypsin (EC 3.4.21.1). In silico digestion and bioactive peptides were characterized using the BIOPEP-UMW database. Quantitative evaluation was carried out by calculating the bioactive peptides release frequencies. As a result, we found eleven types of biologically active peptides (stimulants, renin inhibitors, DPP4 inhibitors, antioxidants, ACE inhibitors, DPP3 inhibitors, hypocholesterolemic agents, CaMPDE inhibitors, regulators, anticarcinogenic agents, and immunomodulators). According to the findings, DPP4 inhibitors had the highest frequency of release, turning milk into a potential source of metabolites that suppress DPP4 activity, which, in turn, could lead to a reduced degradation of incretin hormones. Despite the different values ​​in their frequency of release, the total number of bioactive peptides did not show a statistically significant difference (p> 0.05) among the milk proteins from each of the four species under study.La creciente demanda de alimentos de alto valor nutricional ha inclinado el consumo de lácteos de leche bovina por leche proveniente de otras especies de rumiantes; no obstante, la fracción proteica de la leche es relativamente constante y se compone de caseínas: S1-caseína, -caseína, -caseína, y seroproteínas; -lactoalbúmina y -lactoglobulina. En la actualidad, los estudios de péptidos bioactivos derivados de la leche se centran en proteínas obtenidas de una única especie y se efectúan empleando enzimas ajenas al sistema digestivo humano. La presente investigación realizó una comparación cuantitativa de los péptidos bioactivos obtenidos de las caseínas y seroproteínas presentes en la leche de bovino (Bos taurus), oveja (Ovis aries), cabra (Capra hircus) y búfalo (Bubalus bubalis) a partir de procesos de digestión in silico catalizados por proteasas presentes en el sistema digestivo humano: pepsina (EC 3.4.23.1), tripsina (EC 3.4.21.4) y quimotripsina (EC 3.4.21.1). La caracterización de péptidos bioactivos y la digestión in silico fue realizada mediante BIOPEP-UMW. La evaluación cuantitativa se efectuó a partir del cálculo de frecuencias de liberación. Los resultados mostraron once clases de péptidos con acción biológica: estimulantes, inhibidores de Renina, inhibidores de DPP4, antioxidantes, inhibidores de ACE, inhibidores de DPP3, hipocolesterolémicos, inhibidores de CaMPDE, reguladores, anticancerígenos e inmunomoduladores. Los péptidos inhibidores de DPP4 presentaron la mayor frecuencia de liberación, lo que sitúa a la leche como una potencial fuente de metabolitos supresores de la acción proteolítica de DPP4 en la degradación de incretinas. Pese a los distintos valores de frecuencias de liberación, los cuatro perfiles totales de péptidos bioactivos correspondientes a la leche de cada especie no mostraron una diferencia estadísticamente significativa (p>0.05)

Effect of Activated Carbon Made from Cocoa (Theobroma Cacao L.) Shells on the Adsorption of Iron in Aquifer Water

This research aims to determine the effect of activated carbon obtained from cocoa husks (Theobroma cacao L.) on the adsorption of iron (II) present in water of an aquifer for human consumption. Charcoal was prepared at different carbonization temperatures (500, 600 and 700 °C) for 30 minutes and activated with phosphoric acid in the proportions of 1:1. Iron (II) adsorption was determined as a function of variations in mixing speed, contact time, charcoal dosage and stirring speed. It was determined that, over the range considered, agitation speeds had no significant effect on the percentage of iron (II) removal, being the dose of activated carbon and temperature, the most influential variables. The water samples had an initial iron concentration of 3.15 mg/L and 4 mg/L. The best iron (II) adsorption result was obtained with activated carbon at the carbonization temperature of 700 °C, with a mass of 1.5 g of carbon, with efficiencies of 93 % and 98 % for both samples considered. Based on the results, it was concluded water for human consumption is treatable with activated carbon derived from Theobroma cacao L. for the adsorption of iron (II), considering that this parameter is below the maximum limit of 0.3 mg/L allowed by current regulations

Reportes clínicos breves

Tuberculosis y embarazo: una experiencia institucional. Autor: Luz Amparo Díaz Cruz. Tutora: Dra. María Teresa Peralta Abello, Profesora Asociada del Departamento de Ginecología. / Artritis séptica en el paciente pediátrico Autores: Fabio M. Ramírez, Patricia Uricoechea y Carlos Vásquez. Tutores: Drs. Mauricio Palau, Infectólogo, Pediatra, Profesor Asociado; Edgar Rojas, Pediátra, Profesor Asociado; Eduardo Alvarez, Jefe del Servicio de Infectología, Hospital Pediátrico de La Misericordia. / Resistencia a la insulina.  Autor: Dr. Guido Lastra. Profesor Asociado del Departamento de Medicina Interna. Unidad de Endocrinología. / Riesgo de pérdida visual postoperatoria en glaucoma avanzado. Autor: Dr. John Jairo Martínez Cardona. Tutor: Dr. Gabriel Ortiz Arizmendi, Instructor Asociado, Departamento de Cirugía, Facultad de Medicina. Universidad Nacional de Colombia

Informe del encuentro de Universidades Latinoamericanas y Europeas en pedagogía hospitalaria. Red UNITWIN-UNESCO de pedagogía hospitalaria.

El presente informe da cuenta del trabajo realizado con instituciones de Educación Superior de América Latina y Europa, representantes de Ministerios de Educación y Salud, representantes de organizaciones sin fines de lucro dedicadas a la Pedagogía Hospitalaria de Latinoamérica y El Caribe