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Hernandez-Fernandez J, Lambis H, Reyes RV. Application of Pyrolysis for the Evaluation of Organic Compounds in Medical Plastic Waste Generated in the City of Cartagena-Colombia Applying TG-GC/MS. Int J Mol Sci 2023; 24:ijms24065397. [PMID: 36982471 PMCID: PMC10049447 DOI: 10.3390/ijms24065397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/03/2023] [Accepted: 02/07/2023] [Indexed: 03/14/2023] Open
Abstract
In this study, the thermal degradation and pyrolysis of hospital plastic waste consisting of polyethylene (PE), polystyrene (PS), and polypropylene (PP) were investigated using TG-GC/MS. The identified molecules with the functional groups of alkanes, alkenes, alkynes, alcohols, aromatics, phenols, CO and CO2 were found in the gas stream from pyrolysis and oxidation, and are chemical structures with derivatives of aromatic rings. They are mainly related to the degradation of PS hospital waste, and the alkanes and alkenes groups originate mainly from PP and PE-based medical waste. The pyrolysis of this hospital waste did not show the presence of derivatives of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, which is an advantage over classical incineration methodologies. CO, CO2, phenol, acetic acid and benzoic acid concentrations were higher in the gases from the oxidative degradation than in those generated in the pyrolysis with helium. In this article, we propose different pathways of reaction mechanisms that allow us to explain the presence of molecules with other functional groups, such as alkanes, alkenes, carboxylic acids, alcohols, aromatics and permanent gases.
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Affiliation(s)
- Joaquín Hernandez-Fernandez
- Chemistry Program, Department of Natural and Exact Sciences, San Pablo Campus, University of Cartgena, Cartagena 130015, Colombia
- Chemical Engineering Program, School of Engineering, Universidad Tecnológica de Bolivar, Parque Industrial y Tecnológico Carlos Vélez Pombo Km 1 Vía Turbaco, Cartagena 130001, Colombia
- Department of Natural and Exact Science, Universidad de la Costa, Barranquilla 080002, Colombia
- Fundacion Universitaria Tecnologico Comfenalco—Cartagena, Cr 44 D N 30A, 91, Cartagena 130001, Colombia
- Correspondence: ; Tel.: +57-301-5624990
| | - Henry Lambis
- Fundacion Universitaria Tecnologico Comfenalco—Cartagena, Cr 44 D N 30A, 91, Cartagena 130001, Colombia
| | - Ricardo Vivas Reyes
- Chemistry Program, Department of Natural and Exact Sciences, San Pablo Campus, University of Cartgena, Cartagena 130015, Colombia
- Fundacion Universitaria Tecnologico Comfenalco—Cartagena, Cr 44 D N 30A, 91, Cartagena 130001, Colombia
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Martínez Gil J, Reyes RV, Bastidas-Barranco M, Giraldo L, Moreno-Piraján JC. Biodiesel Production from Transesterification with Lipase from Pseudomonas cepacia Immobilized on Modified Structured Metal Organic Materials. ACS Omega 2022; 7:41882-41904. [PMID: 36440125 PMCID: PMC9685751 DOI: 10.1021/acsomega.2c02873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 09/28/2022] [Indexed: 06/16/2023]
Abstract
This research presents the modification of MOF-199 and ZIF-8 using furfuryl alcohol (FA) as a carbon source to subsequently fix lipase from Pseudomonas cepacia and use these biocatalysts in the transesterification of African palm oil (APO). The need to overcome the disadvantages of free lipases in the biodiesel production process led to the use of metal organic framework (MOF)-type supports because they provide greater thermal stability and separation of the catalytic phase, thus improving the activity and efficiency in relation to the use of free lipase, disadvantages that could not be overcome with the use of other types of catalysts used in transesterification/esterification reactions for the production of biodiesel. The modification of MOFs ZIF-8 and MOF-199 with FA increases the pore volume which allows better immobilization of Pseudomonas cepacia lipase (PCL). The results show that these biocatalysts undergo transesterification with biodiesel yields above 90%. Additionally, studies were carried out on the effect of (1) enzyme loading, 2) enzyme immobilization time, (3) enzyme immobilization temperature, and (4) pH on the % immobilization of the enzyme and the specific activity. The results show that the highest immobilization efficiency for the FA@ZIF-8 support has a value of 91.2% when the load of this support was 3.5 mg/mg and has a specific activity of 142.5 U/g protein. The FA@MOF-199 support presented 80.3% enzyme immobilization and 125% U/g specific activity protein. We established that the specific activity increases in the period from 0.5 to 5.0 h for the systems under investigation. After this time, both the specific activity and the % efficiency of enzyme immobilization decrease. Therefore, 5.0 h (immobilization efficiency of 95 and 85% for FA@MOF-199, respectively) was chosen as the most appropriate time for PCL immobilization. Methods of adding methanol, with three and four steps, were tested, where biodiesel yields greater than 90% were obtained for the biocatalysts synthesized in this work (FA@ZIF-8-PCL and FA@MOF-199-PCL) and above 70% for free PCL, and the maximum yield was reached at a molar ratio between methanol and APO of 4:1 when using the one-step method under the same reaction conditions (as mentioned above). Only the results of FA@ZIF-8-PCL are presented here; however, it should be noted that the results for biocatalyst FA@MOF-199-PCL and lipase-free PCL presented the same behavior. The order of biocatalyst performance was FA@ZIF-8-PCL > FA@MOF-199-PCL > PCL-Free, which demonstrates that the use of FA as a modifier is a novel aspect in the conversion of palm oil into biodiesel components.
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Affiliation(s)
- José
Manuel Martínez Gil
- Grupo
de Investigación Catálisis y Materiales. Facultad de
Ciencias Básicas y Aplicadas, Universidad
de La Guajira, Km 5 vía a Maicao., Riohacha440007, Colombia
- Grupo
de Investigación Química Cuántica y Teórica,
Facultad de Ciencias Exactas y Naturales, Universidad de Cartagena, Campus de Zaragocilla, Cartagena130005, Colombia
- Grupo
de Investigación Desarrollo de Estudios y Tecnologías
Ambientales del Carbono (DESTACAR). Facultad de Ingenierías, Universidad de La Guajira, Km 5 vía a Maicao., Riohacha440007, Colombia
- Facultad
de Ciencias, Departamento de Química, Grupo de Investigación
en Sólidos Porosos y Calorimetría, Universidad de los Andes, Bogotá01, Colombia
| | - Ricardo Vivas Reyes
- Grupo
de Investigación Química Cuántica y Teórica,
Facultad de Ciencias Exactas y Naturales, Universidad de Cartagena, Campus de Zaragocilla, Cartagena130005, Colombia
| | - Marlon Bastidas-Barranco
- Grupo
de Investigación Desarrollo de Estudios y Tecnologías
Ambientales del Carbono (DESTACAR). Facultad de Ingenierías, Universidad de La Guajira, Km 5 vía a Maicao., Riohacha440007, Colombia
| | - Liliana Giraldo
- Facultad
de Ciencias, Departamento de Química, Grupo de Calorimetría, Universidad Nacional de Colombia, Sede Bogotá01, Colombia
| | - Juan Carlos Moreno-Piraján
- Facultad
de Ciencias, Departamento de Química, Grupo de Investigación
en Sólidos Porosos y Calorimetría, Universidad de los Andes, Bogotá01, Colombia
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Vivas Reyes R, Morales A, Márquez Lázaro J, Varela R, Herrera L, Vivas Gómez C. Acoplamiento molecular y modelado tridimensional por homología de flavonoides derivados de amentoflavona con las neuraminidasas H1N1 y H5N1 del virus de gripe aviar. Rev Colomb Quim 2022. [DOI: 10.15446/rev.colomb.quim.v50n3.97430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
El virus de la influenza A es el responsable de la gripe aviar, condición patológica que afecta principalmente aves, caballos y mamíferos marinos, sin embargo, el subtipo H5N1 tiene la capacidad de infectar a los humanos de forma rápida, exponiéndolos a un posible evento pandémico. Por tanto, el objetivo de este estudio fue realizar el acoplamiento molecular y modelado tridimensional por homología de flavonoides derivados de amentoflavona con las neuraminidasas H1N1 y H5N1 del virus de gripe aviar. Inicialmente, se obtuvo por homología la estructura 3D de la neuraminidasa H1N1. Seguido, se realizó un acoplamiento molecular de H1N1 con seis ligandos (F36, Ginkgetin, 3S,3R, 5S,5R, 6S y 6R), y más adelante H5N1 y los ligandos F36, Ginkgetin, 5R y 6R. Finalmente, a los complejos obtenidos se les realizó un análisis de interacciones. Los resultados dejaron en evidencia una relación entre la actividad inhibitoria y las interacciones tipo puente de hidrógeno e hidrofóbicas formadas entre el sitio activo de las neuraminidasas y los ligandos. Además, se observó una mejora en la actividad inhibitoria de los ligandos para la estereoquímica tipo R y sustituyentes poco voluminosos. De ahí que se propongan la evaluación experimental de los ligandos 5R y 6R como potenciales inhibidores de H5N1.
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Reyes RV, Herrera EA, Ebensperger G, Sanhueza EM, Giussani DA, Llanos AJ. Perinatal cardiopulmonary adaptation to the thin air of the Alto Andino by a native Altiplano dweller, the llama. J Appl Physiol (1985) 2020; 129:152-161. [PMID: 32584666 DOI: 10.1152/japplphysiol.00800.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Most mammals have a poor tolerance to hypoxia, and prolonged O2 restriction can lead to organ injury, particularly during fetal and early postnatal life. Nevertheless, the llama (Lama Glama) has evolved efficient mechanisms to adapt to acute and chronic perinatal hypoxia. One striking adaptation is the marked peripheral vasoconstriction measured in the llama fetus in response to acute hypoxia, which allows efficient redistribution of cardiac output toward the fetal heart and adrenal glands. This strong peripheral vasoconstrictor tone is triggered by a carotid body reflex and critically depends on α-adrenergic signaling. A second adaptation is the ability of the llama fetus to protect its brain against hypoxic damage. During hypoxia, in the llama fetus there is no significant increase in brain blood flow. Instead, there is a fall in brain O2 consumption and temperature, together with a decrease of Na+-K+-ATPase activity and Na+ channels expression, protecting against seizures and neuronal death. Finally, the newborn llama does not develop pulmonary hypertension in response to chronic hypoxia. In addition to maintaining basal pulmonary arterial pressure at normal levels the pulmonary arterial pressor response to acute hypoxia is lower in highland than in lowland llamas. The protection against hypoxic pulmonary arterial hypertension and pulmonary contractile hyperreactivity is partly due to increased hemoxygenase-carbon monoxide signaling and decreased Ca2+ sensitization in the newborn llama pulmonary vasculature. These three striking physiological adaptations of the llama allow this species to live and thrive under the chronic influence of the hypobaric hypoxia of life at high altitude.
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Affiliation(s)
- R V Reyes
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
| | - E A Herrera
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
| | - G Ebensperger
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
| | - E M Sanhueza
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - D A Giussani
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - A J Llanos
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
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Anaya Gil JL, Drosos Ramirez JC, Vergara Lorduy JE, Toro Rojas JP, Vivas Reyes R. Evaluación teórica de las propiedades electrónicas y estructurales que afectan a la conductividad eléctrica en copolímeros de furanotiofeno. Rev colomb quim 2019. [DOI: 10.15446/rev.colomb.quim.v48n2.78807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Desde el punto de vista científico y tecnológico ha habido un gran interés en el uso de monosustituyentes de furano y tiofeno como polímeros conductores, debido a sus múltiples aplicaciones como OLED, amplificadores ópticos, nanotecnología, entre otros. Por ello, el propósito de este trabajo fue estudiar los aspectos teóricos que afectan las propiedades electroconductoras de este tipo de moléculas. Se determinaron teóricamente los aspectos estructurales y electrónicos que influyeron en la conductividad de copolímeros de furano–tiofeno monosustituidos, al utilizar grupos carboxilos, metilos, hidroxilos, ciano y fluoruros como sustituyentes en el carbono C3 y C10 de cada heterociclo. La diferencia de energía entre el LUMO y el HOMO (band gap, Eg) y el potencial de ionización (PI) fue calculada a partir de las geometrías optimizadas en DFT para el estado neutro, anión y catión. Los PI y la Eg de los copolímeros fueron obtenidos mediante la extrapolación de los valores del oligómero a (1/N) y de una cadena de longitud infinita (1/N=0), obteniéndose una correlación lineal (R=0,99), la cual se mantiene a lo largo de todos los modelos de ajuste de cada copolímero analizado en el estudio.
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