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Previous studies have shown hydrophilic/hydrophobic implant surfaces stimulate/hinder osseointegration. An analogous concept was applied here using common biological functional groups on a model surface to promote oral keratinocytes (OKs) proliferation and hemidesmosomes (HD) to extend implant lifespans through increased soft tissue attachment. However, it is unclear what physicochemistry stimulates HDs. Thus, common biological functional groups (NH2, OH, and CH3) were functionalized on glass using silanization. Non-functionalized plasma-cleaned glass and H silanization were controls. Surface modifications were confirmed with X-ray photoelectron spectroscopy and water contact angle. The amount of bovine serum albumin (BSA) and fibrinogen, and BSA thickness, were assessed to understand how adsorbed protein properties were influenced by physicochemistry and may influence HDs. OKs proliferation was measured, and HDs were quantified with immunofluorescence for collagen XVII and integrin β4. Plasma-cleaned surfaces were the most hydrophilic group overall, while CH3 was the most hydrophobic and OH was the most hydrophilic among functionalized groups. Modification with the OH chemical group showed the highest OKs proliferation and HD expression. The OKs response on OH surfaces appeared to not correlate to the amount or thickness of adsorbed model proteins. These results reveal relevant surface physicochemical features to favor HDs and improve implant soft tissue attachment. info:eu-repo/semantics/publishedVersion

Here, we provide evidence of the path-dependency of the energy components of the energy decomposition analysis scheme, EDA, by studying a set of thirty-one closed-shell model systems with D2h symmetry point group. For each system, we computed EDA components from nine different pathways and numerically showed that the relative magnitudes of the components differ substantially from one path to the other. Not surprisingly, yet unfortunately, the most significant variations in the relative magnitudes of the EDA components appear in the case of species with bonds within the grey zone of covalency and ionicity. We further discussed that the role of anions and their effect on arbitrary Pauli repulsion energy components affects the nature of bonding defined by EDA. The outcome variation by the selected partitioning scheme of EDA might bring arbitrariness when a careful comparison is overlooked J.P. and M.S. thank the Ministerio de Economía y Competitividad (MINECO) of Spain (projects CTQ2017-85341-P, PID2020-113711GB-I00, PID-2019-106830GB-I00 and MDM2017-0767) and the Generalitat de Catalunya (2017SGR39 and 2017SGR348). D.M.A. thanks ERC StG (EU805113) and University of Saarland for financial support. CFN thanks National Science Centre, Poland 2020/39/B/ST4/02022 for partially funding this research

El presente trabajo de investigación trata el estudio de los parámetros físicos y químico de la autodepuración del río El Cinto, Ubicado en la parroquia de Lloa, cuyo objetivo fue determinar la capacidad de autodepuración en un tramo del río El Cinto a través de análisis físico-químico y que mediante las fuentes bibliográficas. Se determinó que la capacidad de autodepuración es uno de los factores que influye en la calidad de agua, por esta razón se analizó los parámetros en 3 puntos del tramo del río, en la parte alta, media y baja, en la cual se tomó muestras in situ para obtener pH, temperatura y oxígeno disuelto. En el laboratorio se realizó DBO5, DQO, coliformes fecales y sólidos suspendidos totales. Se utilizó la metodología presente del libro “Standard Metthods for the examination of water and wastewater”, se obtuvo los procedimientos para cada uno de los parámetros estudiados, de igual manera se identificó las características del río y de la zona de estudio como: caudal, longitud, profundidad y las actividades que se realizan aledañas al río que se presentan con datos que se realizó en un análisis estadístico con el programa Rstudio para conocer las diferencias significativas entre las concentraciones de los días de muestreo. En los resultados se aprecia que algunos parámetros como el pH, temperatura, oxígeno disuelto se encuentra dentro de los criterios de calidad de agua para consumo humano y domestico la cual se encuentra en la norma de calidad ambiental antes mencionada, ya que con los resultados se concluyó que los parámetros restantes se encuentran bajo el criterio de calidad, en este caso las concentraciones de oxígeno disuelto poseen una capacidad de autodepuración la cual con el aumento de la temperatura se puede ver afectado en su concentración. The present research work deals with the study of the physical and chemical parameters of the self-purification of the El Cinto river, located in the parish of Lloa, whose objective was to determine the self-purification capacity in a section of the El Cinto river through physical-chemical analysis and bibliographic sources. It was determined that the self-purification capacity is one of the factors that influence water quality. For this reason, the parameters were analyzed at three points along the river, in the upper, middle and lower sections, where samples were taken in situ to obtain pH, temperature and dissolved oxygen. BOD5, COD, fecal coliforms and total suspended solids were analyzed in the laboratory. The present methodology from the book "Standard Methods for the examination of water and wastewater" was used to obtain the procedures for each of the parameters studied, as well as to identify the characteristics of the river and the study area, such as flow, length, depth and the activities carried out near the river, which were presented in a statistical analysis with the Rstudio program to determine the significant differences between the concentrations on the sampling days. The results show that some parameters such as pH, temperature, dissolved oxygen are within the criteria of water quality for human and domestic consumption which is found in the environmental quality standard mentioned above, since the results concluded that the remaining parameters are under the quality criteria, in this case the concentrations of dissolved oxygen have a self-purification capacity which with the increase in temperature can be affected in its concentration.

El presente trabajo tuvo como objetivo central el determinar la afectación de los suelos colindantes a plantaciones de eucalipto (Eucalyptus globulus) y pino (Pinus radiata) mediante el análisis de los parámetros físicos, químicos y biológicos del suelo en la comunidad de Pesillo, cantón Cayambe. Se realizó un levantamiento descriptivo de la ubicación y cobertura del uso de suelo y cobertura vegetal natural en el área de estudio. El uso y cobertura vegetal natural para cada tipo de estudio y su respectiva superficie para observar los cambios físicos, químicos y biológico que presenta cada zona en un análisis del suelo. Se determinó la afectación de los suelos colindantes a plantaciones de Eucalipto (Eucalyptus globulus) y Pino (Pinus radiata) mediante el análisis de los parámetros físicos, químicos y biológicos del suelo en la comunidad de Pesillo, Cantón Cayambe. Los resultados de los análisis de laboratorio mostraron que el suelo es un suelo franco arenoso con un contenido de materia orgánica moderado, lo cual es un buen indicador de la fertilidad del suelo. Los resultados del análisis de varianza mostraron que no existían diferencias significativas en los parámetros físico-químicos del suelo entre las zonas de estudio. Se encontró que la abundancia y la diversidad de los macroinvertebrados eran homogéneas en las diferentes zonas de estudio, sin embargo, los resultados del análisis de varianza mostraron que existían diferencias significativas en la abundancia y la diversidad de los macroinvertebrados entre las zonas de estudio. Se evidenció que la clase de macroinvertebrados más abundante es la clase insecta. Concluyendo así que el establecimiento de plantaciones de eucalipto y pino en el país ha generado una serie de problemas ambientales, especialmente en los ecosistemas naturales. The main objective of this study was to determine the impact of soils adjacent to eucalyptus (Eucalyptus globulus) and pine (Pinus radiata) plantations by analyzing the physical, chemical and biological parameters of the soil in the community of Pesillo, Cayambe canton. A descriptive survey of the location and coverage of land use and natural vegetation cover in the study area was carried out. The use and natural vegetation cover for each type of study and its respective surface to observe the physical, chemical and biological changes that each zone presents in a soil analysis. The impact of soils adjacent to Eucalyptus (Eucalyptus globulus) and Pine (Pinus radiata) plantations was determined by analyzing the physical, chemical and biological parameters of the soil in the community of Pesillo, Cantón Cayambe. The results of the laboratory analysis showed that the soil is a sandy loam soil with a moderate organic matter content, which is a good indicator of soil fertility. The results of the analysis of variance showed that there were no significant differences in soil physicochemical parameters between the study areas. The abundance and diversity of macroinvertebrates were found to be homogeneous in the different study zones, however, the results of the analysis of variance showed that there were significant differences in the abundance and diversity of macroinvertebrates among the study zones. It was evident that the most abundant macroinvertebrate class is the insect class. Thus, concluding that the establishment of eucalyptus and pine plantations in the country has generated a series of environmental problems, especially in natural ecosystems.

Ab initio electronic excited state calculations are necessary for the quantitative study of photochemical reactions, but their accurate computation on classical computers is plagued by prohibitive resource scaling. The Variational Quantum Deflation (VQD) is an extension of the quantum-classical Variational Quantum Eigensolver (VQE) algorithm for calculating electronic excited state energies, and has the potential to address some of these scaling challenges using quantum computers. However, quantum computers available in the near term can only support a limited number of quantum circuit operations, so reducing the quantum computational cost in VQD methods is critical to their realisation. In this work, we investigate the use of adaptive quantum circuit growth (ADAPT-VQE) in excited state VQD calculations, a strategy that has been successful previously in reducing the resources required for ground state energy VQE calculations. We also invoke spin restrictions to separate the recovery of eigenstates with different spin symmetry to reduce the number of calculations and accumulation of errors in computing excited states. We created a quantum eigensolver emulation package - Quantum Eigensolver Building on Achievements of Both quantum computing and quantum chemistry (QEBAB) - for testing the proposed adaptive procedure against two existing VQD methods that use fixed-length quantum circuits: UCCGSD-VQD and k-UpCCGSD-VQD. For a lithium hydride test case we found that the spin-restricted adaptive growth variant of VQD uses the most compact circuits out of the tested methods by far, consistently recovers adequate electron correlation energy for different nuclear geometries and eigenstates while isolating the singlet and triplet manifold. This work is a further step towards developing techniques which improve the efficiency of hybrid quantum algorithms for excited state quantum chemistry, opening up the possibility of exploiting real quantum computers for electronic excited state calculations sooner than previously anticipated.

We discuss the possibility of using mixed-valence (MV) dimers comprising paramagnetic metal ions as molecular cells for quantum cellular automata (QCA). Thus, we propose to combine the underlying idea behind the functionality of QCA of using the charge distributions to encode binary information with the additional functional options provided by the spin degrees of freedom. The multifunctional ('smart') cell is supposed to consist of multielectron MV d(n)-d(n+1)-type (1 ≤ n ≤ 8) dimers of transition metal ions as building blocks for composing bi-dimeric square planar cells for QCA. The theoretical model of such a cell involves the double exchange (DE), Heisenberg-Dirac-Van Vleck (HDVV) exchange, Coulomb repulsion between the two excess electrons belonging to different dimeric half-cells and also the vibronic coupling. Consideration is focused on the topical case in which the difference in Coulomb energies of the two excess electrons occupying nearest neighboring and distant positions significantly exceeds both the electron transfer integral and the vibronic energy. In this case the ground spin-state of the isolated square cell is shown to be the result of competition of the second-order DE producing a ferromagnetic effect and the HDVV exchange that is assumed to be antiferromagnetic. In order to reveal the functionality of the magnetic cells, the cell-cell response function is studied within the developed model. The interaction of the working cell with the polarized driver-cell is shown to produce an antiferromagnetic effect tending to suppress the ferromagnetic second-order DE. As a result, under some conditions the electric field of the driver cell is shown to force the working cell to exhibit spin-switching from the state with maximum dimeric spin values to that having minimal spin values.

The optimization of nonlinear optical properties for “real-life” applications remains a key challenge for both experimental and theoretical approaches. In particular, for two-photon processes, maximizing the two-photon action cross section (TPACS), the figure of merit for two-photon bioimaging spectroscopy, requires simultaneously controlling all its components. In the present Letter, a series of difluoroborates presenting various heterocyclic rings as an electron acceptor have been synthesized and their absorption, fluorescence, photoisomerization, and two-photon absorption features have been analyzed using both experimental and theoretical approaches. Our results demonstrate that the TPACS values can be fine-tuned by changing the position of a single heteroatom, which alters the fluorescence quantum yields without changing the intrinsic two-photon absorption cross section. This approach offers a new strategy for optimizing TPACS J.M.L. is grateful for financial support from the Spanish MICIN PGC2018-098212-B-C22 and the Catalan DIUE 2017SGR39

The influence of stereochemistry on the self-assembly of phenylalanine (Phe) dipeptides bearing aromatic fluorenyl groups at both the N- and C-termini (Fmoc, OFm) has been investigated. For this purpose, Fmoc–d-Phe–l-Phe–OFm and Fmoc–l-Phe–l-Phe–OFm have been examined considering a wide variety of solvents, which differ in dielectric constant and volatility. Results reveal that replacement of l-Phe by d-Phe has a major impact on the self-assembly propensities, restricting drastically the structural diversity and polymorphism shown by the homochiral dipeptide. Thus, the analogous heterochiral dipeptide shows a great propensity to form micro/nanofibers, independently of the environmental conditions. Theoretical calculations revealed that the stability of antiparallel disposition is much higher (a factor of ca. 15) for Fmoc–d-Phe–l-Phe–OFm than that for Fmoc–l-Phe–l-Phe–OFm, which has been attributed to the hydrophobic core formed in the former. Overall, results suggest that control of the backbone chirality is a potent and versatile strategy to drive and finely tune the self-assembly propensities of highly aromatic peptides., This work was supported by MINECO (RTI2018-098951-B-I00, RTI2018-101827-B-I00, and CTQ2013-40855-R), AGAUR (2017SGR359 and 2017SGR373), and Gobierno de Aragon (research group Aminoacidos y Peptidos E19_20R). Support for the research of C.A. was received through the prize “ICREA Academia” for excellence in research funded by the Generalitat de Catalunya.

ilustraciones, diagramas, tablas El triamtereno, un compuesto diurético de primera línea en algunos países incluido dentro del grupo de los ahorradores de potasio presenta poca solubilidad en agua. Con el propósito de mejorar este parámetro, y en consecuencia su disposición en el organismo, se sintetizaron dos nuevos compuestos en los que se modificó la estructura del TAT con manganeso y zinc, usando sus respectivos cloruros. La síntesis se llevó a cabo en solución agua:metanol. Estos compuestos fueron caracterizados a través de microscopía electrónica de barrido SEM y difracción de Rayos X en polvo. Adicionalmente, se observaron los perfiles de disolución en el tiempo en medio acuoso, evidenciando que este parámetro mejoró en los nuevos compuestos sintetizados. La caracterización de los nuevos compuestos se realizó a través de técnicas espectroscópicas como absorción UV-VIS, infrarrojo y raman. Los resultados obtenidos se contrastaron con termogramas y perfil de dilución. Se determinó el carácter fotosensibilizador del TAT y de los nuevos compuestos con Zn y Mn en medios alcohólicos. Se realizaron medidas de actinometría en estado estacionario que permitieron establecer el rendimiento cuántico de oxígeno molecular singulete generado por los nuevos compuestos. Adicionalmente, se realizaron medidas de rendimiento cuántico de fluorescencia, para aportar a la caracterización de los materiales, con miras al estudio posterior de sus aplicaciones como marcadores fluorescentes. La caracterización se completó con ensayos citotóxicos, genotóxicos y con prueba de hemolisis; con lo que fue posible demostrar el potencial antineoplásico de los nuevos compuestos sintetizados sobre la línea celular tumoral MCF-7. (Texto tomado de la fuente) Triamterene, a first line diuretic compound in some countries included in the group of potassium sparing compounds, presents poor solubility in water. In order to improve this parameter, and consequently its disposition in the organism, two new compounds were synthesized in which the TAT structure was modified with manganese and zinc, using their respective chlorides. The synthesis was carried out in water:methanol solution. These compounds were characterized by SEM scanning electron microscopy and powder X-ray diffraction. Additionally, the dissolution profiles over time in aqueous medium were observed, evidencing that this parameter improved in the new synthesized compounds. The characterization of the new compounds was carried out through spectroscopic techniques such as UV-VIS absorption, infrared and Raman. The results obtained were contrasted with thermograms and dilution profile. The photosensitizing character of TAT and the new compounds with Zn and Mn in alcoholic media was determined. Steady state actinometry measurements were performed to establish the singlet molecular oxygen quantum yield generated by the new compounds. Additionally, fluorescence quantum yield measurements were performed to contribute to the characterization of the materials, with a view to the subsequent study of their applications as fluorescent markers. The characterization was completed with cytotoxic, genotoxic and hemolysis assays; thus, it was possible to demonstrate the antineoplastic potential of the new compounds synthesized on the MCF-7 tumor cell line. Maestría Magíster en Ciencias - Química Área Curricular en Ciencias Naturales

Following our study on hydrogen-bonded (HB) complexes [Phys. Chem. Chem. Phys., 2018, 20, 19841], the physical nature of interaction-induced (non)linear optical properties of another important class of molecular complexes, namely halogen-bonded (XB) systems, was analyzed in this study. The excess electronic and nuclear relaxation (hyper)polarizabilities of nine representative XB complexes covering a wide range of halogen-bond strengths were computed. The partitioning of the excess properties into individual interaction-energy components (electrostatic, exchange, induction, dispersion) was performed by using the variational-perturbational energy decomposition scheme at the MP2/aug-cc-pVTZ level of theory and further supported by calculations with the SCS-MP2 method. In the case of the electronic interaction-induced properties, the physical composition of Δαel and Δγel was found to be very similar for the two types of bonding, despite the different nature of the binding. For Δβel, the XB complexes exhibit a more systematic interplay of interaction-energy contributions compared to the HB systems studied in the previous work. Our analysis revealed that the patterns of interaction-energy contributions to the interaction-induced nuclear-relaxation contributions to the linear polarizability and the first hyperpolarizability are very similar. For both properties the exchange repulsion term is canceled out by the electrostatic and delocalization terms. The physical composition of these contributions is analogous to those observed for the HB complexes J. M. L. is grateful for financial support from the Spanish MICIN PGC2018-098212-B-C22 and the Catalan DIUE 2017SGR39

La fibra de la planta de piña es un biopolímero compuesto en su mayoría por material lignocelulósico. La biodegradación de este material en su entorno natural ocasiona una gran problemática a los agricultores, pues esta tarda en descomponerse de 8 a 13 meses y ocasiona un retardo en la producción de este cultivo, por lo que los cultivadores optan por aplicar agroquímicos que producen daños ambientales como la contaminación de las fuentes hídricas, o generan quemas masivas de esta biomasa para acelerar este proceso. Considerando lo anterior, este trabajo de grado se propuso estudiar la posible funcionalidad tecnológica de la fibra natural obtenida de la piña en las variedades oro miel y perolera, para lo cual se evaluó el método de extracción manual y máquina desfibradora, siendo este último el de mejor desempeño. Se obtuvo un rendimiento de 1,9% para la variedad oro miel y 3,8% para la perolera. En cuanto a su composición química se determinó que las fibras de la hoja de la piña están constituidas principalmente del 85% de holocelulosa (67% corresponde a la α-celulosa y un 8% de lignina). Mediante la técnica Microscopía Electrónica de Barrido (SEM, Scanning Electron Microscope, por su significado en inglés) se estableció su morfología, la cual mostró haces de fibras compactas con un grosor aproximado de 160 - 170 micrómetros para la variedad oro miel y 60 - 70 micrómetros para la variedad perolera. Se estudiaron propiedades mecánicas de las fibras obtenidas como tensión, fuerza máxima y deformación. La variedad perolera presentó una tensión de 198,944 MPa, una fuerza máxima de 25 N, y una deformación de 0,74 mm. The fiber of the pineapple plant is a biopolymer composed mostly of lignocellulosic material. The biodegradation of this material in its natural environment causes a great problem for farmers, since it takes 8 to 13 months to decompose and causes a delay in the production of this crop, so that growers choose to apply agrochemicals that cause damage. environmental conditions such as the contamination of water sources or generate massive burns of this biomass to accelerate this process. Considering the above, this degree work was proposed to study the possible technological functionality of the natural fiber obtained from the pineapple in the varieties oro miel and perolera, for which the method of manual extraction and shredding machine was evaluated, the latter being that of better performance. A yield of 1.9% was obtained for the gold honey variety and 3.8% for the perolera. Regarding its chemical composition, it was determined that the fibers of the pineapple leaf are mainly made up of 85% holocellulose (67% corresponds to α-cellulose and 8% lignin). By means of the Scanning Electron Microscope (SEM) technique, its morphology was established, which showed bundles of compact fibers with an approximate thickness of 160 - 170 micrometers for the honey gold variety and 60 - 70 micrometers for the perolera variety. The mechanical properties of the fibers obtained were studied, such as tension, maximum force, and deformation. The perolera variety presented a tension of 198.944 MPa, a maximum force of 25 N, and a strain of 0.74 mm. Químico Ambiental http://www.ustabuca.edu.co/ustabmanga/presentacion Pregrado

“Los canales de calcio tipo T son proteínas transmembranales de importancia biológica por su participación en la excitabilidad de las neuronas. La sobreexcitación de estas proteínas puede manifestarse en enfermedades tálamo-corticales, padecimientos de dolor neuropático o neurogénico, depresión, enfermedades cardiacas y trastornos neurológicos como la epilepsia. Dentro de las moléculas que modulan la función de estos canales iónicos, las moléculas bloqueadoras son de importancia farmacológica para desarrollar nuevos tratamientos o conocer el mecanismo de acción celular de otros bloqueadores existentes. En este proyecto de tesis se realiza un análisis desde el enfoque de la química teórica para caracterizar a las moléculas bloqueadoras con actividad cannabinoide, así como un análisis desde el enfoque del acoplamiento molecular (Molecular Docking) y simulaciones de dinámica molecular para evaluar la interacción de las moléculas bloqueadoras con el canal de calcio tipo T en particular el subtipo Cav3.2. Adicionalmente se evalúa la interacción de la molécula genisteína en interacción con el subtipo Cav3.3. El análisis cuántico involucra la caracterización espectroscópica IR y de NMR de H1 y C13 , ya sea para establecer el nivel de teoría adecuado o para establecer las estructuras moleculares de estudio”.

El presente artículo muestra un análisis biocinemático del ejercicio volteo simple extendido adelante con medio giro, perteneciente a la disciplina de salto de la gimnasia con rueda alemana. Para el desarrollo del presente estudio se realizaron las grabaciones de 60 saltos gimnásticos ejecutados por tres gimnastas de la selección colombiana y un gimnasta de la selección suiza. Posterior a este proceso, se evaluaron las variables biocinemáticas ángulo de salida y ángulo de rotación, utilizando el software Kinovea, versión 0.8.15. Los datos hallados se analizaron con el software SPSS, versión 24. Los resultados descriptivos del valor de la media estadística se graficaron y se correlacionaron estadísticamente, lo que permitió validar que un ángulo de salida que oscile entre los 24º y los 27º y un ángulo de rotación cercano a los 180º son los factores que determinan una adecuada ejecución técnica del volteo simple extendido adelante con medio giro. Finalmente, estos hallazgos brindaron elementos al entrenamiento para adicionar un medio giro al elemento gimnástico analizado y permitieron así que un gimnasta colombiano ocupara el sexto puesto en el Campeonato Mundial de Gimnasia con Rueda Alemana, que se llevó a cabo en Suiza durante 2018. This article shows a biokinematic analysis of the simple extended forward turning exercise with ½ turn, of the jumping discipline of German wheel gymnastics. For the development of the present study, recordings were made of 60 gymnastic jumps executed by three Colombian Selection gymnasts and one Swiss Selection gymnast. After this process, the biokinematic variables exit angle and rotation angle were evaluated using the Kinovea software version 0.8.15. The data found were analyzed with the SPSS software version 24, the descriptive results of the statistical mean value were plotted and statistically correlated allowing to validate that an exit angle that oscillates between 24º and 27º and a rotation angle close to the 180º, are the factors that determine an adequate technical execution of the simple turn extended forward with ½ turn. Finally, these findings provide training elements to add a ½ turn to the gymnastic element analyzed, thus allowing a Colombian gymnast to occupy sixth place in the German wheel gymnastics world championships, which took place in Switzerland in 2018.

The effects of the vibronic coupling in quantum cellular automata (QCA) based on the square planar mixed valence (MV) molecular cells comprising four paramagnetic centers (spin cores) and two excess mobile electrons are analyzed in the important particular case when the Coulomb energy gap between the ground antipodal diagonal-type two-electron configurations and the excited side-type configurations considerably exceeds both the one-electron transfer parameter (strong U-limit) and the vibronic stabilization energy. Under such conditions the developed model involves the second-order double exchange, the Heisenberg-Dirac-Van Vleck (HDVV) exchange and the vibronic coupling of the excess electrons with the molecular B-1g-vibration composed of four full-symmetric local vibrations. The latter interaction is shown to significant amplify the ability of the electric field produced by the driver-cell to polarize the excess electrons in the working cell, which can be termed 'the effect of the vibronic enhancement of the cell-cell interaction'. This effect leads to a redetermination of the conditions for switching between different spin-states, as well as to a significant change in the shapes of the cell-cell response functions. The obtained results demonstrate the importance of the vibronic coupling in all aspects (such as description of a free cell and cell-cell response) of the theory of molecular QCA based on MV clusters.

Ilustraciones y tablas In the present study, the solubility of sulfadiazine in aqueous mixtures of Carbitol and N-methyl-2-pyrrolidone (NMP) at 278.15 K - 313.15 K was analyzed. It was found that the solubility of sulfadiazine in aqueous Carbitol mixtures did not vary with temperature. For aqueous mixtures of NMP, it was found that the trend of the increase in solubility was different for rich mixtures in NMP. This could be by a possible phase change of the crystalline structure of sulfadiazine. The thermodynamic properties of solution, mixture and transfer were calculated. The preferential solvation parameters of sulfadiazine were determined using the experimental solubility values and the thermodynamic functions of solution by means of the inverse Kirkwood-Buff integrals (IKBI) method. For both cosolvent systems, it was found that sulfadiazine is preferentially solvated by water in water-rich mixtures, probably due to the hydrophobic hydration phenomenon, but preferentially solvated by Carbitol or NMP in cosolvent-rich mixtures, probably due to the behavior of sulfadiazine as Lewis acid in front of the cosolvent molecules. The enthalpy-entropy relationship of the (NMP + water) system was analyzed, finding a non-linear relationship by plotting the enthalpy of solution as a function of the Gibbs energy of solution. Finally, when evaluating the sulfadiazine solubility values calculated using the semi-empirical Jouyban-Acree and the extended Hildebrand models, notable deviations were obtained with respect to the experimental values. The smallest mean percentage deviations % MPD were achieved with the extended Hildebrand model using an order 5 polynomial, obtaining a value of 0.88% for the (Carbitol + water) system and 1.47% for the (NMP + water) system, both at 313.15 K. En el presente estudio se determinó la solubilidad de la sulfadiazina en mezclas acuosas de Carbitol y N-metil-pirrolidona (NMP) en el rango de temperaturas de 278,15 K a 313,15 K. Se encontró que la solubilidad de la sulfadiazina en mezclas acuosas de Carbitol no varió con la temperatura. Para la solubilidad de sulfadiazina en mezclas acuosas de NMP se encontró que la tendencia del aumento de solubilidad era diferente para mezclas ricas en NMP, lo que podría ser explicado por un posible cambio de fase de la estructura cristalina de la sulfadiazina. Se calcularon además las funciones termodinámicas aparentes de solución, mezcla y transferencia de dichos sistemas. Los parámetros de solvatación preferencial de la sulfadiazina se hallaron utilizando los valores de solubilidad experimentales y las funciones termodinámicas de solución por medio del método de las integrales inversas de Kirkwood-Buff (IKBI, Inverse Kirkwood-Buff Integrals). Para ambos sistemas de cosolventes, se encontró que la sulfadiazina es solvatada preferencialmente por agua en mezclas ricas en agua, debido probablemente al fenómeno de hidratación hidrofóbica, pero solvatada preferencialmente por Carbitol o NMP en mezclas ricas en cosolvente, debido probablemente al comportamiento de la sulfadiazina como ácido de Lewis frente a las moléculas de los cosolventes. Se analizó la relación entálpica-entrópica del sistema (NMP + agua) encontrando una relación no lineal al graficar la entalpía de solución en función de la energía de Gibbs de solución. Finalmente, al evaluar los valores de solubilidad de sulfadiazina calculados mediante los modelos semiempíricos de Jouyban-Acree y el modelo extendido de Hildebrand se obtuvieron desviaciones notables con respecto a los valores experimentales. Las menores desviaciones promedio porcentuales se lograron con el modelo extendido de Hildebrand utilizando un polinomio de orden 5 para calcular el factor W, obteniendo un porcentaje de 0,88% para el sistema (Carbitol + agua) y de 1,47% para el sistema (NMP + agua), ambos a 313,15 K. (Texto tomado de la fuente). Incluye anexos Maestría Magíster en Ciencias Farmacéuticas

Recopilación de resúmenes de los trabajos presentados en el XXII Congreso Argentino de Fisicoquímica y Química Inorgánica (XXII CAFQI), llevado a cabo en modalidad virtual los días 19, 21, 23, 27 y 29 de abril de 2021 en la Universidad Nacional de La Plata., Facultad de Ciencias Exactas

Tesis (Doctora en Ciencias Químicas) - - Universidad Nacional de Córdoba. Facultad de Ciencias Químicas, 2020 La química atmosférica estudia los compuestos químicos presentes en la atmósfera, su origen, distribución, transformación en otros compuestos y finalmente, su remoción. Estas sustancias pueden estar en el estado gaseoso, líquido o sólido. La composición de la atmósfera está dominada por los gases N2 y O2 en proporciones que se mantienen invariables en el espacio hasta altitudes de aproximadamente 100 km. Todos los restantes compuestos presentes son minoritarios, con muchos de ellos presentes, incluso, en cantidades trazas. En la tabla 1.1 se muestra la composición química actual de la atmósfera a nivel superficial. Como puede verse, más del 99,9% de la atmósfera está conformada por compuestos químicos que permanecen constantes a cualquier altitud: N2 (78,1 %), O2 (20,9 %) y Ar (0,93 %).[1] Excluyendo el vapor de agua, los otros constituyentes minoritarios CO2, O3, etc., comprenden el 1% restante de la atmósfera, pero a pesar de sus abundancias muy pequeñas, las especies traza como el vapor de agua y el O3 tienen un rol clave en el balance de energía de la Tierra mediante la participación en procesos radiativos. Algunas de estas especies son creadas y destruidas en regiones particulares y/o están estrechamente vinculadas con los fenómenos de transporte; debido a esto, la concentración de estos compuestos minoritarios es altamente variable. [2] 2022-10-31 Fil: Garavagno, María de los Ángeles. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina. Fil: Pino, Gustavo Ariel. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica; Argentina. Fil: Pino, Gustavo Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Fisicoquímica de Córdoba; Argentina. Fil: Ortiz, Patricia Inés. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica; Argentina. Fil: Ortiz, Patricia Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Fisicoquímica de Córdoba; Argentina. Fil: Nicotra, Viviana Estela. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Fil: Nicotra, Viviana Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina. Fil: Asís, Ramón. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Bioquímica Clínica; Argentina. Fil: Asís, Ramón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina. Fil: Tucceri, María Eugenia. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Fil: Tucceri, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Fisico-Químicas teóricas y aplicadas; Argentina.

“El efecto Leidenfrost es un fenómeno en el que un líquido, en contacto con una superficie cuya temperatura sea mayor que el punto de ebullición del líquido, produce una capa de vapor aislante que evita que el fluido se evapore rápidamente. Aunque este fenómeno se ha estudiado para una gota líquida sobre una superficie s ́olida o, incluso, sobre una superficie líquida, se conoce poco sobre el efecto de dos gotas de líquidos diferentes que interactúan entre sí sobre la misma superficie sólida a temperatura Leidenfrost. En este estudio, se caracterizó el comportamiento de once líquidos cuando están a su temperatura Leidenfrost y se encontró que el tiempo de vida de los líquidos en estas condiciones varía linealmente a una razón de 1 κ, donde κ es la conductividad térmica del vapor producido por elliquidó. Luego, se investigó la coalescencia de diferentes líquidos en el estado Leidenfrost y se propuso un mecanismo que explica por qué no hay una coalescencia directa entre líquidos distintos cuando interactúann en estas condiciones, a saber, el triple efecto Leidenfrost.”

Soil quality provides essential functions for life and fertility related to minimal damage to the ecosystem, sustains a permanent agricultural activity. This work aims to investigate the physical-chemical quality of the soil in the municipal garden of Inhangapi, in the state of Pará, and possible qualitative changes in a stretch of the Inhangapi River. Sampling was carried out in periods of different rainfall patterns according to the National Institute of Meteorology, in order to identify the influence of rainfall on the evaluated parameters. Subsequently, physical-chemical analyzes were performed at the Laboratory of the Agricultural Technology Center located at the Federal Rural University of the Amazon. With the physical-chemical analyzes of the soil it was verified that there is a need for conservationist practices that aim to improve the cultivation area, through liming, consortium with legumes for better nitrogen supply and maintaining the soil cover to avoid erosion and leaching and use of composting in order to improve the supply of organic matter and improve water retention, since the soil is sandy. The rapid water body assessment protocol was also applied to a stretch of the river. Greater care is needed on the stretch of river where the protocol was applied, such as the use of riparian forest to help with the silting up of the river bed, resulting in water protection in the surrounding area. La calidad del suelo proporciona funciones esenciales para la vida y la fertilidad relacionadas con el daño mínimo al ecosistema, mantiene una actividad agrícola permanente. Este trabajo tiene como objetivo investigar la calidad físico-química del suelo en el jardín municipal de Inhangapi, en el estado de Pará, y los posibles cambios cualitativos en un tramo del río Inhangapi. El muestreo se realizó en períodos de diferentes patrones de lluvia según el Instituto Nacional de Meteorología, con el fin de identificar la influencia de la lluvia en los parámetros evaluados. Posteriormente, se realizaron análisis físico-químicos en el Laboratorio del Centro de Tecnología Agrícola ubicado en la Universidad Federal Rural del Amazonas. Con los análisis físico-químicos del suelo se verificó que existe la necesidad de prácticas conservacionistas que tengan como objetivo mejorar el área de cultivo, a través de encalado, consorcio con legumbres para un mejor suministro de nitrógeno y mantener la cubierta del suelo para evitar la erosión y la lixiviación y el uso de compostaje para mejorar el suministro de materia orgánica y mejorar la retención de agua, ya que el suelo es arenoso. El protocolo de evaluación rápida del cuerpo de agua también se aplicó a un tramo del río. Se necesita un mayor cuidado en el tramo del río donde se aplicó el protocolo, como el uso del bosque ribereño para ayudar con el sedimento del lecho del río, lo que resulta en la protección del agua en los alrededores. A qualidade do solo proporciona funções indispensáveis a vida e a fertilidade relacionada ao mínimo do dano ao ecossistema, sustenta uma atividade agrícola permanente. Portanto, objetivou-se averiguar a qualidade físico-química do solo do horto municipal de Inhangapi, no estado do Pará, e possíveis alterações qualitativas em um trecho do rio Inhangapi. Foram realizadas amostragens em períodos de diferentes regimes pluviométricos de acordo com o Instituto Nacional de Meteorologia, a fim de identificar a influência das chuvas nos parâmetros avaliados. Posteriormente, foram realizadas análises físico-químicas no Laboratório do Centro de Tecnologia Agropecuária localizado na Universidade Federal Rural da Amazônia. Com as análises físico-químicas do solo foi verificado que há necessidade de práticas conservacionistas que visem melhorar a área de cultivo, através de calagem, consórcio com leguminosas para melhor aporte de nitrogênio e mantendo a cobertura do solo para evitar erosão e lixiviação e uso de compostagem com o intuito de melhorar o aporte de matéria orgânica e melhorar a retenção de água, uma vez que o solo é arenoso. Também foi aplicado o protocolo de avaliação rápida do corpo hídrico em um trecho do rio. São necessários maiores cuidados no trecho do rio onde foi aplicado o protocolo, como uso de mata ciliar no auxílio para o problema de assoreamento do leito do rio acarretando na proteção hídrica da área próxima.

At low excitation energies nitrobenzene photoreleases NO with low translational and rotational energy, while at higher excitation energies NO is photoreleased with both low and high translational and rotational energy. The fast products are formed through a singlet-triplet crossing (STC) region featuring an oxaziridine ring, while a ground state roaming mechanism was suggested to produce the slow molecules. Computing translational and rotational energies performing CASSCF classical dynamics, we here prove how the same oxaziridine STC can account for both fast and slow photoproducts, depending on the region of the seam through which the ground state is populated. A roaming-type STC/CI has also been characterized, from which slow NO molecules can also be formed through a roaming photodegradation mechanism, here in the excited state. The higher accessibility of the oxaziridine STC mechanism, 1.53 eV lower in energy than the roaming path, questions the contribution of roaming in nitrobenzene NO photoproduction.

FeV(O)(OH) species have long been proposed to play a key role in a wide range of biomimetic and enzymatic oxidations, including as intermediates in arene dihydroxylation catalyzed by Rieske oxygenases. However, the inability to accumulate these intermediates in solution has thus far prevented their spectroscopic and chemical characterization. Thus, we use gas-phase ion spectroscopy and reactivity analysis to characterize the highly reactive [FeV(O)(OH)(5tips3tpa)]2+ (32+) complex. The results show that 32+ hydroxylates C–H bonds via a rebound mechanism involving two different ligands at the Fe center and dihydroxylates olefins and arenes. Hence, this study provides a direct evidence of FeV(O)(OH) species in non-heme iron catalysis. Furthermore, the reactivity of 32+ accounts for the unique behavior of Rieske oxygenases. The use of gas-phase ion characterization allows us to address issues related to highly reactive intermediates that other methods are unable to solve in the context of catalysis and enzymology., FeV(O)(OH) species have long been thought to play a role in a range of enzymatic oxidations, but their characterization has remained elusive. Here, using gas-phase ion spectroscopy, the authors characterize an FeV(O)(OH) species and find that its reactivity mimics that of Rieske oxygenases.

The quality of meat related to sensory parameters is widely observed by the end consumer, where the public becomes increasingly demanding. In order to obtain such a product, the industry uses various means, including the use of antibiotic that promotes growth. However, Brazil is the largest exporter of broiler chickens, making it adapt to legislative requirements, which in turn has been restricting and prohibiting the use of growth-promoting antibiotics, justified by the emergence of resistance cross. The addition of essential oil to the animal diet can help by acting as antimicrobials and antioxidants, performing actions similar to the growth-promoting antibiotic, and therefore become a possible substitute for this compound. Thus, the objective of this study is to evaluate the moisture content, ash, protein, lipids, pH, loss from cooking, shear strength and color in chicken breast cuts that were subjected to different diets based on corn and bran soybean with the addition of growth promoting antibiotic and essential oil in different concentrations (0; 0.05; 0.10; 0.15 kg / ton of feed). All methodologies were carried out through laboratory research of a quantitative nature. Satisfactory results were obtained for all physical and physical-chemical parameters when compared to the literature, in addition to showing that the addition of the essential oil of oregano and cinnamon, in a concentration of 0.10 kg / ton of feed, presented similar results when compared meat cuts from treatment with the use of growth-promoting antibiotic, enabling new studies for replacement in the national production chain. La calidad de la carne calificada para los parámetros sensoriales es ampliamente observada por el consumidor final, donde el público se vuelve cada vez más exigente. Para usar el producto en la industria, use varios medios, incluido el uso del antibiótico que promueve el crecimiento. Sin embargo, Brasil se encuentra como el mayor exportador de pollos de engorde, lo que lo hace adecuado para las legislaturas, lo que a su vez ha estado restringiendo y prohibiendo el uso de antibióticos que promueven el crecimiento, justificado por el aumento de la resistencia cruzada. La adición de aceite esencial a la dieta animal puede ayudar actuando como antimicrobianos y antioxidantes, realizando acciones similares al antibiótico que promueve el crecimiento y, por lo tanto, convirtiéndose en un posible sustituto de este compuesto. Por lo tanto, el objetivo de este trabajo es evaluar las teorías de cenizas, cenizas, proteínas, lípidos, pH, pérdida de cocción, resistencia al corte y color en cortes de pechugas de pollo que se utilizaron en diferentes dietas utilizadas en maíz y harina de soja con la adición de antibióticos que promueven el crecimiento y aceite esencial en diferentes filtros (0; 0.05; 0.10; 0.15 kg / tonelada de alimento). Todas las metodologías se llevaron a cabo a través de investigaciones de laboratorio de naturaleza cuantitativa. Se obtienen resultados satisfactorios para todos los criterios físicos y físico-químicos en comparación con la literatura, además de mostrar que una adición de aceite esencial de orégano y canela, en una concentración de 0,10 kg / tonelada de alimento, presenta resultados similares. cuando se usa para cortes de tratamiento con promotores de crecimiento antibiótico, lo que permite nuevos estudios para el reemplazo en la cadena de producción nacional. A qualidade da carne relacionada aos parâmetros sensoriais é bastante observada pelo consumidor final, onde o público torna-se cada vez mais exigente. Para a obtenção de tal produto a indústria utiliza-se de diversos meios, entre eles o uso de antibiótico promotor de crescimento. No entanto, o Brasil encontra-se como o maior país exportador de frangos de corte, fazendo com que o mesmo se adeque às exigências legislativas, que por sua vez vem restringindo e proibindo o uso de antibiótico promotor de crescimento, justificadas pelo surgimento de resistência cruzada. A adição de óleo essencial na dieta animal pode auxiliar pelo fato de atuar como antimicrobianos e antioxidantes, realizando ações semelhantes ao do antibiótico promotor de crescimento, e, portanto, se tornam um possível substituinte deste composto. Sendo assim, objetiva-se com o presente trabalho avaliar o teor de umidade, cinzas, proteína, lipídeos, pH, perda por cozimento, força de cisalhamento e cor em cortes de peitos de frangos que foram submetidos à diferentes dietas baseadas em milho e farelo de soja com adição de antibiótico promotor de crescimento e óleo essencial em diferentes concentrações (0; 0,05; 0,10; 0,15 kg/ton de ração). Todas as metodologias foram realizadas por meio pesquisas laboratoriais de natureza quantitativa. Obtiveram-se resultados satisfatórios para todos os parâmetros físicos e físico-químicos quando comparados à literatura, além de evidenciar que a adição do óleo essencial de orégano e canela, em concentração de 0,10 kg/ton de ração, apresentou resultados similares quando comparado aos cortes cárneos do tratamento com uso de antibiótico promotor de crescimento, possibilitando novos estudos para substituição em cadeia de produção nacional.

In this article, we propose a vibronic pseudo Jahn–Teller model for partially delocalized mixed-valence molecules aimed to describe the magnetic coupling between the localized spins mediated by the delocalized electron. The simplest partially delocalized system that retains the main studied features is assumed to consist of a one-electron mixed-valence dimer, which is connected to the two terminal magnetic ions. The model involves the following key interactions: electron transfer in the spin-delocalized subsystem of a mixed-valence molecule, which is mimicked by a dimeric unit, coupling of the itinerant electrons with the molecular vibrations, and isotropic magnetic exchange between the localized spins and delocalized electron. The proposed model, which can be referred to as the vibronic “toy” model, is intentionally restricted to the named basic interactions and therefore it is aimed to describe only the key features of a wide class of mixed-valence clusters exhibiting partial electronic delocalization w...

We investigate the impact of lipidation on the self-assembly of two peptide fragments from the gastrointestinal peptide hormone PYY3–36. The lipopeptides C16IKPEAP and C16IKPEAPGE contain the first 6 and 8 amino acid residues, respectively, from the PYY3–36 peptide sequence, with a palmitoyl C16 tail attached at the N-terminus. These lipopeptides form spherical micelles in aqueous solution, above a critical micelle concentration (cmc), which is pH-dependent. Modeling of small-angle X-ray scattering data along with molecular dynamics simulations shows the formation of micelles with a hydrophobic interior and a well-hydrated exterior. The lipopeptides have a disordered conformation over the pH and temperature ranges studied. The cmc is found to be independent of temperature, pointing to athermal micellization. In contrast to the presence of hydrated micelles in solution, ß-sheet amyloid fibrils form in dried samples. Thus, the nanostructure of lipidated PYY3–36 fragment peptides can be tuned by control of pH or concentration, for future applications.

The photophysics of nitroaromatics compounds stand out for being characterized by an ultrafast decay into the triplet manifold and by a significant value of the triplet quantum yield. The latter quantity can change dramatically from one system to another, as proven for the molecules 2- nitronaphthalene, 1-nitronaphthalene, and 2methyl-1nitronaphthale, whose triplet quantum yield have been previously measured to be 0.93 ± 0.15, 0.64 ± 0.12, and 0.33 ± 0.05, respectively (J. Phys. Chem. A 2013, 117, 14100). In the present contribution we rationalize the reported trend for the triplet quantum yield on the basis of the different ability that the excited S 1 state has in the three molecules to reach a non-previously characterized conical intersection with the ground state. Such a path is in competition with the one leading to triplet states population, which, on the basis of the present static description, appear to be equally favorable in the three systems. Performing high-level ab-initio computations, the energy barrier from the S 1 CASPT2//CASSCF minimum to a CASPT2 minimum-energy-crossing-point of the mentioned S 1 /S 0 conical intersection have been computed to follow the same trend than the values of triplet quantum yield in the three nitroaromatics system here under analysis. The CASPT2 minimum-energy-crossing-point have been obtained using the projected constrained optimization method as recently implemented in the Molcas code. The same path has been characterized also for nitrobenzene, obtaining a value for the mentioned energy barrier that nicely fit in the model derived for the three nitro-naphthalene systems, and in agreement with its high value of the triplet quantum yield (greater than 0.8). The ability of the present model to not only rationalize the experimental data of a single molecule but to reproduce a trend for four slightly different systems speaks in favor of its reliability.

El presente proyecto consistió en la evaluación de la eficiencia de remoción de acetaminofén, considerado como un contaminante emergente a escala laboratorio a partir de bioadsorbentes a base de cáscara de cacao y plátano. Se determinó cómo los parámetros (concentración de acetaminofén, tiempo de contacto, biomasa activada y sin activar, cantidad de bioadsorbente y tamaño de partícula) intervienen en la efectividad del proceso de bioadsorción. Luego se procedió a aplicar las isotermas de adsorción de Langmuir y Freundlich para identificar los mecanismos de adsorción que se presentaron durante el tratamiento. Los datos experimentales obtenidos de la adsorción con cáscara de cacao se ajustaron mejor al modelo de Langmuir con un R2 de 0,97 y para la cáscara de plátano presentaron mejor ajuste al modelo de Freundlich con un coeficiente de correlación de 0,99. Se calcularon, los parámetros termodinámicos (ΔG°, ΔH° y ΔS°) para cada uno de los sistemas. La energía libre de Gibbs, confirmó los mecanismos de adsorción obtenidos por las isotermas, los valores negativos de la entalpía mostraron que el proceso de adsorción es exotérmico, los valores positivos de la entropía sugieren que el proceso de adsorción presenta un mayor grado de aleatoriedad y desorden molecular y la relación entre los parámetros termodinámicos demostraron que se presentó un proceso espontáneo de adsorción. Finalmente, se calculó la cinética de adsorción para las dos biomasas con los modelos de pseudo-primer y segundo orden, dando como resultado que la adsorción con cáscara de cacao corresponde al modelo de pseudo segundo orden con un R2 de 0,98. Finalmente, el proceso de adsorción a partir de biomasas activadas presentó mayores eficiencias de remoción en comparación con las biomasas inactivas y la cáscara de plátano demostró ser mejor bioadsorbente para el acetaminofén a una concentración de 10 ppm, un tamaño de partícula de 0,595 mm y 40 gr de biomasa con un 98,99% de remoción, mientras que la cáscara de cacao con la misma concentración y cantidad de adsorbente y tamaño de partícula de 0,841 mm presentó una remoción de 92,48%. The present project consisted of evaluating the efficiency of removal of acetaminophen to laboratory scale from bioadsorbents based on cocoa and banana peels. It was determined how the parameters (acetaminophen concentration, contact time, activated and non-activated biomass, amount of biosorbent and particle size) intervene in the effectiveness of the bioadsorption process. Then, Langmuir and Freundlich adsorption isotherms were applied to identify the adsorption mechanisms that occurred during the treatment. The experimental data obtained from the adsorption with cocoa peel were better adapted to the Langmuir model with an R2 of 0,97 and for the banana peel they presented better adaptation to the Freundlich model with a correlation coefficient of 0,99. The thermodynamic parameters (ΔG°, ΔH° and ΔS°) were calculated for each of the systems. The Gibbs free energy confirmed the adsorption mechanisms obtained by the isotherms, the negative enthalpy values proved that the adsorption process is exothermic, the positive entropy values indicated that the adsorption process presents a greater degree of randomness and Molecular disorder and the relationship between thermodynamic parameters showed that a spontaneous adsorption process occurred. Finally, the adsorption kinetics for the two biomasses were calculated with the pseudo-first and second order models, resulting in the cocoa shell adsorption corresponding to the pseudo-second order model with an R2 of 0,98. Finally, the adsorption process from activated biomasses presented higher removal efficiencies compared to inactive biomasses, and banana peel proved to be a better bioadsorbent for acetaminophen at a concentration of 10 ppm, a particle size of 0,595 mm and 40 gr of biomass with 98,99% removal, while the cocoa shell with the same concentration and amount of adsorbent and particle size of 0,841 mm had a removal of 92,48%. Ingeniero Ambiental http://www.ustavillavicencio.edu.co/home/index.php/unidades/extension-y-proyeccion/investigacion Pregrado

The amino acid lysine has been shown to prevent water crystallization at low temperatures in saturated aqueous solutions [S. Cerveny and J. Swenson, Phys. Chem. Chem. Phys., 2014, 16, 22382–22390]. Here, we investigate two ratios of water and lysine (5.4 water molecules per lysine (saturated) and 11 water molecules per lysine) by means of the complementary use of computer simulations and neutron diffraction. By performing a detailed structural analysis we have been able to explain the anti-freeze properties of lysine by the strong hydrogen bond interactions of interstitial water molecules with lysine that prevent them from forming crystalline seeds. Additional water molecules beyond the 1 : 5.4 proportion are no longer tightly bonded to lysine and therefore are free to form crystals., This work was supported by the Spanish Ministry of Science and Innovation through the project FIS2014-54734-P, MINECO (grants FIS2015-66879-C2-1-P, FIS2017-82625-P and PID2019-104650GB-C21) and by the Generalitat de Catalunya under the projects 2014-SGR-581 and 2017-SGR-042. The UK Science and Technology Facilities Council is gratefully acknowledged for partial financial support and beam time access at the ISIS Facility (RB1220294). A. Henao would like to thank the Thomas Young Centre for the Junior research fellowship supporting a stay with C. D. Lorenz. S. Cerveny thanks CSIC (LINKB20012).

The molecular dynamics in the ambient-pressure solid phase of 1,1,2-trichloroethane is studied by means of broadband dielectric spectroscopy and molecular dynamics simulations. The dielectric spectra of polycrystalline samples obtained by crystallization from the liquid phase exhibit, besides a space-charge relaxation associated with accumulation of charges at crystalline domain boundaries, two loss features arising from dipolar molecular relaxations. The most prominent and slower of the two loss features is identified as a configurational leap of the molecules which involves a simultaneous change in spatial orientation and structural conformation, namely between two isomeric forms (gauche+ and gauche-) of opposite chirality. In this peculiar dynamic process, the positions of the three chlorine atoms in the crystal lattice remain unchanged, while those of the carbon and hydrogen atoms are modified. This dynamic process is responsible for the disorder observed in an earlier X-ray diffraction study and confirmed by our simulation, which is present only at temperatures relatively close to the melting point, starting 40 K below. The onset of the disorder is visible as an anomaly in the temperature dependence of the dc conductivity of the sample at exactly the same temperature. While the slower relaxation dynamics (combined isomerization/reorientation) becomes increasingly more intense on approaching the melting point, the faster dynamics exhibits significantly lower but constant dielectric strength. On the basis of our molecular dynamics simulations, we assign the faster relaxation to large fluctuations of the molecular dipole moments, partly due to large-angle librations of the chloroethane species. Fil: Romanini, Michela. Universidad Politécnica de Catalunya; España Fil: Mitsari, Efstratia. Universidad Politécnica de Catalunya; España Fil: Tripathi, Pragya. Universidad Politécnica de Catalunya; España Fil: Serra, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina Fil: Zuriaga, Mariano Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina Fil: Tamarit, Josep Lluis. Universidad Politécnica de Catalunya; España Fil: Macovez, Roberto. Universidad Politécnica de Catalunya; España

Las asignaturas del area de Quimica Fisica del Grado en Farmacia, entre las que se encuentran Tecnicas Instrumentales (2o curso, 2o cuatrimestre) y Fisicoquimica (1er curso, 2o cuatrimestre), ambas de caracter obligatorio, siguen siendo con mucho aquellas que encabezan la lista con mayor porcentaje de suspensos en la titulacion, de ahi la necesidad de seguir trabajando en mejorar la asimilacion y comprension de sus contenidos. En este curso academico 2017/2018 se ha propuesto una nueva estrategia basada en el empleo de fichas dirigidas para fomentar el trabajo en grupo de alumnos, y alentar asi, su razonamiento deductivo y su capacidad critica. La innovacion empleada fue llevada a cabo en dos ciclos de mejora encadenados, con una duracion de 15 horas cada uno, obteniendose resultados constatables que denotan la mejora en la asimilacion de los contenidos con el consecuente aprendizaje significativo del alumno Fisicoquimica, Tecnicas Instrumentales, Grado en Farmacia, Docencia Universitaria, Experimentacion Docente Universitaria

DGT (Diffusion Gradients in Thin films) was designed to sample trace metals in situ at their natural concentrations. The setup and the experimental deployment conditions were established to allow interpretation of a linear accumulation of metal with time, using a simple expression based on a steady-state flux under perfect sink conditions. However, the extension of DGT to a wide range of analytes and its use under varied conditions has shown that, in some situations, these conditions are not fulfilled, so that accumulations with time are nonlinear. Previously, when such curvature was observed, concentrations in solution could not be reliably calculated. Here, we present fundamentally derived equations that reproduce the time accumulation for three situations: (i) kinetic limitations in the binding to the resin, (ii) saturation or equilibrium effects, or (iii) non-negligible competitive effects. We show how the accumulations can be quantified, in terms of the required kinetic and thermodynamic constants, and provide practical guidance for their use to obtain reliable estimates of solution concentrations. Solutions containing Mg or Mn, where all three situations can prevail, are used as examples. Calculated concentrations show reasonable agreement with the experimentally known values and with the results of a numerical model of the system, significantly improving, the estimations based on perfect sink conditions., Such an approach opens up the possibility of using DGT more widely in challenging systems and allows DGT data to be interpreted more fully. Financial support from FEDER and the Spanish Ministry of Education and Science (Project Nos. CTM2012-39183, CTM2013-48967 and CTM2016-78798) is gratefully acknowl- edged