Sample records for MODELOS DE VALENCIA (valency model)
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1

Generación de modelos matemáticos correlacionales entre afinidad y descriptores topológicos moleculares de antagonistas de glicina en receptores de glutamato/ Mathematical models to correlate molecular topology with substrate affinity of the glycine antagonist in glutamate receptors

Narváez, Guillermo; Lareo, Leonardo; Rincón, Javier
2007-03-01

Resumen en español Introducción. Los modelos matemáticos que correlacionan la estructura química con la actividad biológica son útiles en el diseño de nuevos fármacos, y pueden emplearse para predecir el comportamiento biológico de moléculas nuevas químicamente relacionadas. Objetivos. Generar un modelo matemático que correlacione la afinidad y la topología molecular de antagonistas de glicina en el receptor de glutamato subclase NMDA y proponer nuevas moléculas con actividad a (mas) ntagonista. Materiales y métodos. Mediante los índices de conectividad molecular se codificó la estructura electrónica y el patrón de enlace atómico de 45 antagonistas de glicina. La correlación entre los índices de conectividad y la afinidad de los antagonistas se determinó mediante análisis de regresión. Resultados. El índice de conectividad que mejor describió el comportamiento de la afinidad fue 4Xvpc, indicando la importancia de los heteroátomos, de la adyacencia de los sustituyentes sobre el anillo aromático y del delta de valencia de los sustituyentes. Las ecuaciones generadas pueden utilizarse para la predicción de la afinidad de nuevos antagonistas, y el modelo sugirió los requerimientos estructurales para diseñar compuestos con elevada afinidad. Con base en ello se proponen 12 moléculas nuevas, de las cuales tres parecen ser bastante promisorias, habiéndose calculado teóricamente su afinidad mediante las ecuaciones desarrollas. Como control de la metodología matemática desarrollada se utilizó el análisis de interacción energética . Conclusión. Es posible analizar matemáticamente la estructura química de antagonistas de glicina mediante índices de conectividad, generando ecuaciones que modelan el comportamiento de unión al receptor y aportan información útil en el diseño de nuevos antagonistas. Resumen en inglés Introduction. Mathematical models that correlate chemical structure with biological activity have been useful in the design of new drugs and can be used to predict biological behavior of new, chemically related molecules. Objectives. A mathematical model was generated to correlate the substrate affinities with variations in the molecular topology of glycine antagonists in NMDA sub-class glutamate receptor and, subsequently, to propose new molecules with antagonist activit (mas) y. Materials and methods. By use of molecular connectivity indexes, the electronic structure and atomic bonding patterns of 45 glycine antagonists were coded. Correlation between connectivity indexes and antagonist affinity was determined by regression analysis. Results. The connectivity index that best described affinity behavior was 4Xvpc, which indicates the relative importance of heteroatoms, the vicinity of aromatic ring substitutes, and valency gradient. The equations generated predicted new antagonist affinities, and the model was able to suggest structural requirements for designating compounds with increased affinity. Twelve new molecules were proposed, from which three appeared promising-based of the affinities previously calculated by means of the new equations. Energetic interaction analysis was developed as a control for the mathematical methodology. Conclusion. Glycine antagonists’ structure were analyzed mathematically by means of connectivity indexes. The equations modeled receptor behavior and contributed useful information for new antagonist design.

Scientific Electronic Library Online (Spanish)

3

The physics of glueballs

Mathieu, Vincent; Kochelev, Nikolay; Vento, Vicente
2009-01-01

Digital.CSIC (Spain)

5

Systematics of the quadrupole-quadrupole interaction and convergence properties

Fayache, M.S.; Moya de Guerra, Elvira; Sarriguren, Pedro; Zamick, L.
1999-11-01

Digital.CSIC (Spain)

7

Spin-dependent effective interactions for halo nuclei

Garrido, Eduardo; Fedorov, D.V.; Jensen, A.S.
2003-07-24

Digital.CSIC (Spain)

8

Optical studies of GaAs quantum wells strained to GaP

Prieto, J. A.; Armelles Reig, Gaspar; Pistol, M. E.; Castrillo, P.; Silveira, Juan Pedro; Briones Fernández-Pola, Fernando
1997-06-23

Digital.CSIC (Spain)

9

Optical properties of InSb layers confined by InP

Utzmeier, T.; Armelles Reig, Gaspar; Postigo, Pablo Aitor; Briones Fernández-Pola, Fernando
1997-08-15

Digital.CSIC (Spain)

10

In-beam gamma-ray spectroscopy and shell-model description of Y-85,Y-86 isotopes

Rusu, C.; Ur, C. A.; Bucurescu, D.; Iordachescu, A.; Marginean, N.; Cata-Danil, G.; Ionescu-Bujor, M.; Ivascu, M.; Bazzacco, D.; Kroll, T.; Lenzi, S.; Lunardi, S.; Menegazzo, R.; Alvarez, C.R.; De Angelis, G.; Gadea, Andrés; Napoli, D.
2008-12-13

Digital.CSIC (Spain)

11

Excitons in {311} oriented superlattices: optical anisotropies

Armelles Reig, Gaspar; Castrillo, P.; Domínguez, P. S.; González, Luisa; Ruiz, A.; Contreras-Solorio, D. A.; Velasco, V. R.; García-Moliner, F.
1993-01-01

Digital.CSIC (Spain)

12
13

Electronic state characterization of SiOx thin films prepared by evaporation

Barranco Quero, Ángel; Yubero Valencia, Francisco; Espinós Manzorro, Juan Pedro; Groening, P.; González-Elipe, Agustín R.
2005-06-08

Digital.CSIC (Spain)

14

Electronic potential of a chemisorption interface

Zhao, Jin; Pontius, Niko; Winkelmann, Aimo; Sametoglu, Vahit; Kubo, Atsushi; Borisov, Andrei G.; Sánchez-Portal, Daniel; Silkin, Viatcheslav M.; Chulkov, Eugene V.; Echenique, Pedro M.; Petek, Hrvoje
2008-08-13

Digital.CSIC (Spain)

16

Coupling of valence particles/holes to 68,70Ni studied via measurements of the B(E2) strength in 67,69,70Ni and 71Cu

Mach, H.; Lewitowicz, M.; Stanoiu, M.; Becker, F.; Blomqvist, J.; García Borge, María José; Boutami, R.; Cederwall, B.; Dlouhy, Z.; Fogelberg, B.; Fraile, Luis M.; Georgiev, G.; Grawe, H.; Grzywacz, R.; Johansson, P. I.; Klamra, W.; Lukyanov, S.; Mineva, M.; Mrazek, J.; Neyens, G.; Oliveira Santos, F. de; Pfützner, M.; Penionzhkevich, Yu. E.; Ramström, E.; Sawicka, M.
2003-05-19

Digital.CSIC (Spain)

17

Continuum excitations in He-6

Aumann, T.; Aleksandrov, D.; Axelsson, L.; Baumann, T.; García Borge, María José; Chulkov, L. V.; Cub, J.; Dostal, W.; Eberlein, B.; Elze, Th. W.; Emling, H.; Geissel, H.; Goldberg, V. Z.; Golovkov, M.; Grünschloβ, A.; Hellström, M.; Hencken, K.; Holeczek, J.; Holzmann, R.; Jonson, B.; Korshenninikov, A. A.; Kratz, J. V.; Kraus, G; Kulessa, R.; Leifels, Y.; Leistenschneider, A.; Leth, T.; Mukha, I.; Münzenberg, G.; Nickel, F.; Nilsson, T.; Nyman, G.; Petersen, B.; Pfützner, M.; Richter, A.; Riisager, K.; Scheidenberger, C.; Schrieder, G.; Schwab, W.; Simon, H.; Smedberg, M. H.; Steiner, M.; Stroth, J.; Surowiec, A.; Suzuki, T.; Tengblad, Olof; Zhukov, M. V.
1999-03-01

Digital.CSIC (Spain)

18

Checkerboard-ordered pattern of Bi0.5Sr0.5MnO3 low-temperature phase probed by x-ray resonant scattering

Subías, G.; García, Joaquín; Beran, P.; Sánchez, María Concepción; Garcia Muñoz, Josep Lluis
2006-05-01

Digital.CSIC (Spain)

19

Análisis de contenido de constructos personales en la depresión/ Content analysis of personal constructs in depression

Montesano, Adrián; Feixas, Guillem; Varlotta, Nicolás
2009-10-01

Resumen en español Desde el marco de la Psicología de los Constructos Personales (PCP) de Kelly, es posible estudiar de forma sistemática la construcción subjetiva que las personas hacen de sí mismas y de sus problemas. Feixas et al., destacan la pertinencia del estudio de los sistemas de construcción en la evaluación del trastorno depresivo puesto que miden aspectos que no son suficientemente valorados por las medidas cognitivas estándar sobre los síntomas y las distorsiones cognit (mas) ivas. La mayoría de los trabajos sobre la depresión basados en la PCP se han centrado en las características estructurales, en cambio los aspectos del contenido han recibido menor interés. El propósito de este estudio es realizar un análisis de contenido de los constructos personales en la depresión. Actualmente no existe ningún estudio que haya explorado de forma sistemática las dimensiones de contenido más significativas para esta población. En concordancia con la PCP y otros enfoques cognitivos, hipotetizamos que el contenido de los sistemas de construcción de la muestra depresiva es distinto al de la población normal. En concreto, creemos que la población clínica presenta mayor frecuencia de constructos de tipo moral y emocional en comparación con la muestra no clínica. Para poder poner a prueba estas hipótesis se analizaron los constructos de 106 sujetos, con edades comprendidas entre los 19 y los 57 años, divididos en dos grupos, un grupo clínico (n = 53) de personas diagnosticadas con alguna modalidad depresiva unipolar y otro grupo no clínico (n = 53). Categorizamos el contenido de los constructos elicitados con la técnica de rejilla por medio del Sistema de Categorías de Constructos Personales (SCCP) desarrollado por Feixas et al. El SCCP es un sistema de clasificación compuesto por un total de seis áreas temáticas (moral, emocional, relacional, personal, intelectual y valores e intereses) que se desglosan en 45 categorías para codificar el contenido de los constructos personales. Los principales resultados muestran que existen diferencias significativas entre las distribuciones de frecuencias del contenido de ambas poblaciones. Las personas con depresión (PD) utilizan significativamente más constructos de tipo emocional, y menos de tipo intelectual. Además, en comparación a la muestra normal, los depresivos muestran mayor número de constructos en las categorías >, > y, de forma más destacada, en la dimensión >. Los resultados indican que el patrón prototípico del contenido de los sistemas de constructos de las PD difiere en el énfasis temático predominante. En efecto, de la variedad de acontecimientos de la experiencia, los aspectos conativos resultan especialmente notorios para las personas con depresión. Por otro lado, la carencia de constructos intelectuales y personales refuerza la idea de que las personas con depresión emplean gran parte de su actividad mental en el procesamiento de los aspectos emocionales de la experiencia. Aunque la naturaleza exploratoria de este estudio no permite establecer líneas causales, parece evidente que la focalización de la actividad psicológica de las PD en la dimensión afectiva de la experiencia puede estar desempeñando un papel importante en el mantenimiento de la problemática depresiva. Por último, a partir de las limitaciones de este estudio se proponen algunos diseños para la investigación futura acerca de la relación entre el contenido y la estructura de los sistemas de construcción de las personas con depresión. Resumen en inglés Kelly's Personal Construct Psychology (PCP) proposes that attributing meaning to experience is the most fundamental process of human psychological functioning. He describes psychological activity as a continuous process of creating, testing and revising personal theories (usually implicit) that allow people to understand and anticipate events. Personal constructs are the basic units of these personal theories. Constructs are bipolar contrasts of meaning that form an evolv (mas) ing network through which psychological processes are canalized. This system provides with a limited number of alternative views for explaining, anticipating and participating in life. One of the most significant contributions to psychological research made by PCP concerns the possibility to develop tools for the study of subjective construing. The Role Construct Repertory Grid (RepGrid) has been extensively used to explore the view subjects have of themselves, others and their problems. This technique elicits a sample of verbal descriptions of contrasting alternatives, his or her personal constructs; and provides several measures of self construing (e.g., self-esteem) and systems organization (e.g., complexity). Several authors point out the utility and pertinence of exploring the construct system in the evaluation of depressive disorders. They show the interest of studying the construct systems of depressive patients in order to measure some aspects that symptom and standard cognitive measures of cognitive distortions do not take into account. Depressive mood is highly influenced by the subject's view of him or herself and others, and by the organization of his or her constructs. However, the content of these personal constructs has received far less attention from researchers. The main goal of this article is to complement the PCP model of depression through the content analysis of personal constructs. In contrast with traditional content analysis, we do not evaluate the valency of the content but the principal meaning dimensions through which depressive people describe their interpersonal experience. According to PCP and other cognitive approaches, we hypothesize that the contents of the construct systems in the depressive sample are different from those of the control group. Specifically, we believe that the depressive group will show a higher number of constructs related to emotions and morality. The present study was carried out with 53 patients seeking psychological treatment in various private clinics in Barcelona who met DSM-IV criteria for depressive unipolar disorders. The non-clinical comparison group (n= 53), paired by sex and age with the clinical one, included volunteers recruited by graduate and undergraduate students from the University of Barcelona as part of their practical experience with the RepGrid, after receiving specific training in its administration. To compare the pattern of the construct system of both groups, we categorized the content of the personal constructs elicited with the RepGrid using the Classification System for Personal Constructs (SCCP) developed by Feixas et al. The SCCP is composed of six thematic areas (moral, emotional, relational, personal, intellectual, and values/interests) broken down into 45 different categories. Inter-rater agreement was used to determine the reliability of the SCCP. The results were very satisfactory regarding the percentage of agreement between judges. Cohen's Kappa coefficient confirmed the high level of reliability of the SCCP, which was higher than that obtained in previous studies. Data provides evidence of the differences in content frequency distributions between the clinical and non-clinical groups. People from the depressive sample tend to use more constructs related to emotions and less to intellectual issues. The depressive group showed more constructs within certain specific categories such as >, > and >, and less constructs referring to sexuality. The results indicate that content patterns of depressed people show various specific thematic emphases. Indeed, from the wide range of stimuli coming from interpersonal experience, the emotional aspects acquire a special saliency. Although the exploratory nature of the present study does not allow us to establish causal inference, it seems evident that the tendency of depressive people to focus on the emotional dimension could play an important role in the maintenance of the depressive symptoms. Likewise, the lack of constructs concerning intellectual and personal issues reinforces the idea that depressed people tend to focus on the emotional aspects of the interpersonal experience. The results from the content analysis of specific categories show some contrasting features in the construing systems of both groups. The low self-esteem frequently reported for depressive subjects, a self-demanding attitude, and a negative image of the self are aspects potentially related to the > dimension of meaning, which emerged as the most diverging dimension among the 45 categories within the six areas. On the other hand, constructs within the category > allude to the focus on certain specific interpersonal aspects of experience. The concern about respect and power in relationships turns out to be an important meaning dimension, which is in line with the special interpersonal sensitivity displayed by depressive people when facing judgement and disapproval on the part of significant others. When we hypothesized that depressive people would present a greater number of moral constructs, we were considering that this higher frequency would be reflecting symptomatic aspects about perfectionism and self-demands. The explorative content analysis of this study has not shown enough sensitivity to this important feature of depressive people. Doubtlessly, a more refined research strategy is necessary in order to achieve a better understanding of the role played by morality in the construing systems. Finally, from the limitations of the present study, some issues are proposed for future lines of research. The combination of content and structural aspects, such as implicative dilemmas, seems to be the best alternative for the evaluation of the construct systems of depressive people. Thus, the advantages of studying the organization and the thematic emphases of individual systems of meaning can be combined. In any case, these results provide evidence for the clinical and theoretical advantages of the SCCP in studying the content of personal meaning systems. Therefore, it seems to be a fruitful and useful assessment instrument which allows the clinician to understand the patient's problem in his or her own way of construing.

Scientific Electronic Library Online (Spanish)

20

Acceptor-induced threshold energy for the optical charging of InAs single quantum dots

Moskalenko, E. S.; Karlsson, K. F.; Holtz, P. O.; Monemar, B.; Schoenfeld, W. V.; García, Jorge M.; Petroff, P. M.
2002-11-01

Digital.CSIC (Spain)