The Construction of Double-Ended Classical Trajectories

In the present paper we describe relaxation methods for constructing double-ended classical trajectories. We illustrate our approach with an application to a model anharmonic system, the Henon-Heiles problem. Trajectories for this model exhibit a number of interesting energy-time relationships that appear to be of general use in characterizing the dynamics.Comment: (12 pages, submitted to Chemical Physics Letters. Figures are too large for convenient e-mail access. they are available via anonymous ftp on willie.chem.brown.edu and reside in the directory pub/chem-ph/9407 as the compressed tar file 9407001.tar.Z. If you have difficulty retrieving the figures, please contact J. Doll ([email protected]) for assistance

Fractal Analysis of Protein Potential Energy Landscapes

The fractal properties of the total potential energy V as a function of time t are studied for a number of systems, including realistic models of proteins (PPT, BPTI and myoglobin). The fractal dimension of V(t), characterized by the exponent \gamma, is almost independent of temperature and increases with time, more slowly the larger the protein. Perhaps the most striking observation of this study is the apparent universality of the fractal dimension, which depends only weakly on the type of molecular system. We explain this behavior by assuming that fractality is caused by a self-generated dynamical noise, a consequence of intermode coupling due to anharmonicity. Global topological features of the potential energy landscape are found to have little effect on the observed fractal behavior.Comment: 17 pages, single spaced, including 12 figure

Taming the rugged energy landscape: Techniques for the production, reordering, and stabilization of selected cluster inherent structures

We report our studies of the potential energy surface (PES) of selected binary Lennard-Jones clusters. The effect of adding selected impurity atoms to a homogeneous cluster is explored. Inherent structures and transition states are found by combination of conjugate-gradient and eigenvector-following methods while the topography of the PES is mapped with the help of a disconnectivity analysis. We show that we can controllably induce new structures as well as reorder and stabilize existing structures that are characteristic of higher-lying minima.Comment: 9 pages, 9 figures, accepted for publication in J. Chem. Phy

Efficient Dynamic Importance Sampling of Rare Events in One Dimension

Exploiting stochastic path integral theory, we obtain \emph{by simulation} substantial gains in efficiency for the computation of reaction rates in one-dimensional, bistable, overdamped stochastic systems. Using a well-defined measure of efficiency, we compare implementations of ``Dynamic Importance Sampling'' (DIMS) methods to unbiased simulation. The best DIMS algorithms are shown to increase efficiency by factors of approximately 20 for a $5 k_B T$ barrier height and 300 for $9 k_B T$, compared to unbiased simulation. The gains result from close emulation of natural (unbiased), instanton-like crossing events with artificially decreased waiting times between events that are corrected for in rate calculations. The artificial crossing events are generated using the closed-form solution to the most probable crossing event described by the Onsager-Machlup action. While the best biasing methods require the second derivative of the potential (resulting from the ``Jacobian'' term in the action, which is discussed at length), algorithms employing solely the first derivative do nearly as well. We discuss the importance of one-dimensional models to larger systems, and suggest extensions to higher-dimensional systems.Comment: version to be published in Phys. Rev.

Atuação fonoaudiológica no paciente oncológico disfágico: uso de indicadores

Objective: To describe hospital speech therapy in dysphagic cancer patients. Methods: Crosssectional, retrospective, descriptive, quantitative study, developed in an oncology hospital. The sample consisted of medical records of cancer patients who underwent speech therapy follow-up for dysphagia. Speech therapy indicators of dysphagia were applied and the oral food intake scale (FOIS) was compared before and after speech therapy. Results: The sample had 400 medical records, 189 were included in the GA (outpatient group) and 211 in the IG (hospitalization group). The general mean age of the sample corresponds to 60.35 ± 12.63, with a predominance of men 263 (65.8%). In relation to the neoplasms presented by the patients: 247 head and neck, and 43 esophagus and stomach. In GA 143 (75.7%) patients improved the FOIS scale after therapy, 33 patients (17.5%) maintained the same level and 13 patients (6.9%) presented worsening in FOIS after the therapeutic process. In GI 103 (48.8%) patients improved after therapy, 81 patients (38.4%) maintained the same level on the scale, and 27 patients (12.8%) presented worsening after speech therapy. Conclusion: The establishment of indicators in the performance of dysphagic patients allows identifying and quantifying improvements in care processes, bringing direct benefits to patients, assisting in the characterization of the population served, optimizing and improving processes and results, aiming at improving the quality of services, as well as reducing length of stay and hospital costs. Objetivo: describir la logopedia hospitalaria en pacientes con cáncer de disfagia. Métodos: Estudio transversal, retrospectivo, descriptivo, cuantitativo, desarrollado en un hospital de oncología. La muestra consistió en registros médicos de pacientes con cáncer que se sometieron a terapia del habla por disfagia. Se aplicaron indicadores de disfagia a la terapia del habla y se comparó la escala de ingesta de alimentos orales (FOIS) antes y después de la terapia del habla. Resultados: La muestra tenía 400 registros médicos, 189 se incluyeron en el GA (grupo de pacientes ambulatorios) y 211 en el IG (grupo de hospitalización). La edad media general de la muestra corresponde a 60,35 ± 12,63, con predominio de hombres 263 (65,8%). En cuanto a las neoplasias presentadas por los pacientes: 247 cabeza y cuello y 43 esófago y estómago. En GA 143 (75.7%) los pacientes mejoraron la escala FOIS después de la terapia, 33 pacientes (17.5%) mantuvieron el mismo nivel y 13 pacientes (6.9%) presentaron empeoramiento en FOIS después del proceso terapéutico. En GI 103 (48.8%) los pacientes mejoraron después de la terapia, 81 pacientes (38.4%) mantuvieron el mismo nivel en la escala y 27 pacientes (12.8%) presentaron empeoramiento después de la terapia del habla. Conclusión: El establecimiento de indicadores en el trabajo con el paciente con disfagia permite identificar y cuantificar las mejoras de los procesos de atención, brindando beneficios directos a los pacientes, ayudando en la caracterización de la población atendida, optimizando y mejorando los procesos y resultados, con el objetivo de mejorar la calidad de los servicios. proporcionado, así como la reducción de la estancia hospitalaria y los costos hospitalarios. Objetivo: Descrever a atuação fonoaudiológica hospitalar no paciente oncológico disfágico. Métodos: Estudo transversal, retrospectivo, descritivo, quantitativo, desenvolvido em um hospital oncológico. A amostra foi composta por prontuários de pacientes com câncer que realizaram acompanhamento fonoaudiológico para disfagia. Foram aplicados indicadores fonoaudiológicos de disfagia e comparada a escala de ingestão de alimentação por via oral (FOIS) antes e após terapia fonoaudiológica. Resultados: A amostra contou com 400 prontuários, 189 foram incluídos no GA (grupo ambulatório) e 211 no GI (grupo internação). A média geral da idade da amostra corresponde a 60,35±12,63, sendo o predomínio de homens 263 (65,8%). Quanto às neoplasias apresentadas pelos pacientes: 247 cabeça e pescoço e 43 esôfago e estômago. No GA 143 (75,7%) pacientes melhoraram a escala FOIS pós-terapia, 33 pacientes (17,5%) mantiveram o mesmo nível e 13 pacientes (6,9%) apresentaram piora na FOIS após o processo terapêutico. No GI 103 (48,8%) pacientes melhoraram pós-terapia, 81 pacientes (38,4%) mantiveram o mesmo nível na escala, e 27 pacientes (12,8%) apresentaram piora após a terapia fonoaudiológica. Conclusão: O estabelecimento de indicadores na atuação junto ao paciente disfágico permite identificar e quantificar as melhorias dos processos assistenciais, trazendo benefícios diretos aos pacientes, auxiliando na caracterização da população atendida, otimizando e aprimorando os processos e resultados, visando o aprimoramento da qualidade dos serviços prestados, bem como redução do tempo de internação e dos custos hospitalares.

Quasi-continuous Interpolation Scheme for Pathways between Distant Configurations

A quasi-continuous interpolation (QCI) scheme is introduced for characterizing physically realistic initial pathways from which to initiate transition state searches and construct kinetic transition networks. Applications are presented for peptides, proteins, and a morphological transformation in an atomic cluster. The first step in each case involves end point alignment, and we describe the use of a shortest augmenting path algorithm for optimizing permutational isomers. The QCI procedure then employs an interpolating potential, which preserves the covalent bonding framework for the biomolecules and includes repulsive terms between unconstrained atoms. This potential is used to identify an interpolating path by minimizing contributions from a connected set of images, including terms corresponding to minima in the interatomic distances between them. This procedure detects unphysical geometries in the line segments between images. The most difficult cases, where linear interpolation would involve chain crossings, are treated by growing the structure an atom at a time using the interpolating potential. To test the QCI procedure, we carry through a series of benchmark calculations where the initial interpolation is coupled to explicit transition state searches to produce complete pathways between specified local minima.This work was supported by the Engineering and Physical Sciences Research Council [grant number EP/H042660/1]This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in the Journal of Chemical Theory and Computation, copyright © American Chemical Society after peer review. To access the final edited and published work see http://dx.doi.org/10.1021/ct300483

Características clínicas e fonoaudiológicas de neonatos hospitalizados em uma Unidade de Tratamento Intensivo neonatal com suspeita de doença genética

Introduction: Prematurity is a risk factor for the growth and development of neonates. Objective: To analyze clinical and speech therapy characteristics of neonates hospitalized in the neonatal intensive care unit with suspected genetic disease. Method: Descriptive cross-sectional study conducted in a hospital in southern Brazil with data collection between November 2020 and September 2021. All neonates who were hospitalized in the ICU attended by the public health system and who were suspected of having genetic etiologies were followed up by the Speech-Language Pathology team. All newborn`s medical records with suspected genetic alterations were analyzed and the medical and the speech-language pathology data were analyzed. Results: The sample consisted of 14 premature neonates with a mean gestational age of 36 weeks and 5 days and a mean time of birth, at the time of the speech-language pathology assessment, of 14.6 days of life. Regarding to comorbidities, 71.4% of newborns had some malformation, being multiple in most cases (64.29%). All neonates were using enteral feeding at the time of the speech-language evaluation. At the oral reflexes evaluation it was observed that there was a predominance of patients with a weak rooting reflex and most of them had a present sucking reflex. Conclusions: In this study the sample consisted of mainly premature patients who had multiple malformations and all of them used an alternative feeding route, thus suggesting the demand for speech therapy as part of the multidisciplinary care of these neonates.Introducción: La prematuridad es un factor de riesgo para el crecimiento y desarrollo de los recién nacidos. Objetivo: Analizar las características clinicas y de terapia del habla de recién nacidos hospitalizados en la unidad de cuidados intensivos neonatales (UCI) con sospecha de enfermedad genética. Método: Estudio transversal descriptivo realizado en un hospital en la región del Sur de Brasil. Todos los recién nacidos que fueron hospitalizados en la UTI y que tenían sospecha de tener etiologías genéticas, fueron atendidos por el equipo de Patología del Habla y Lenguaje. Se analizaron todas las historias clínicas de los recién nacidos con sospecha de alteraciones genéticas, extrayéndose datos médicos y de patología del habla y del lenguaje. Resultados: La muestra estuvo constituida por 14 neonatos prematuros con una edad gestacional media de 36 semanas. En cuanto a las comorbilidades, el 71,4% de los recién nacidos presentó alguna malformación, siendo múltiples en la mayoría de los casos (64,29%). Con respecto a los datos de la evaluación de la patología del habla y el lenguaje, todos los recién nacidos estaban usando alimentación enteral. En la evaluación de los reflejos orales, se observó que hubo un predominio de pacientes con reflejo de búsqueda débil, y la mayoría de ellos tenían presente el reflejo de succión. Conclusiones: Se puede decir que en este estudio la muestra estuvo compuesta principalmente por pacientes prematuros, que presentaban plurimalformaciones y que todos utilizaban una vía alternativa de alimentación, sugiriendo así, la necesidad de la fonoaudiología como parte del cuidado multidisciplinario de estos neonatos.Introdução: A prematuridade é um fator de risco para o crescimento e o desenvolvimento dos neonatos. Objetivo: Analisar as características clinicas e fonoaudiológicas de neonatos hospitalizados na unidade de tratamento intensivo (UTI) neonatal com suspeita de doença genética. Material e Método: Estudo transversal descritivo, conduzido em um hospital na região sul do Brasil com coleta de dados entre novembro de 2020 e setembro de 2021. Todos os neonatos que se encontravam internados na UTI, atendidos pelo Sistema Único de Saúde e que apresentavam suspeita de etiologias genéticas foram acompanhados pela equipe de Fonoaudiologia. Foram analisados todos os prontuários dos recém-nascidos com suspeita de alteração genética, extraindo-se os dados médicos e fonoaudiológicos. Resultados: A amostra foi constituída por 14 neonatos prematuros com média de idade gestacional de 36 semanas e 5 dias e uma média de tempo de nascimento, no momento da avaliação fonoaudiológica, de 14,6 dias de vida. No que se refere às comorbidades, 71,4% dos recém-nascidos apresentavam alguma malformação, sendo múltiplas na maior parte dos casos (64,29%). Todos os neonatos estavam fazendo uso de via enteral de alimentação durante a avaliação fonoaudiológica. Na avaliação de reflexos orais, observou-se que houve um predomínio de pacientes com reflexo de procura débil, sendo que a maior parte apresentava reflexo de sucção presente. Conclusões: Pode-se afirmar que, neste estudo, a amostra foi composta por pacientes principalmente prematuros que apresentavam malformações múltiplas e que todos faziam uso de via alternativa de alimentação sugerindo, assim, a necessidade de atendimento fonoaudiológico como parte da assistência multidisciplinar desses neonatos

A two-step target binding and selectivity support vector machines approach for virtual screening of dopamine receptor subtype-selective ligands

10.1371/journal.pone.0039076PLoS ONE76

Associação entre os fatores sociodemográficos e bucais com o bem-estar psicológico em adolescentes escolares

Objective: To investigate the relationship between sociodemographic factors and the performance of activities related to oral function, with psychological well-being in school adolescents. Materials and Methods: School-based, cross-sectional study, conducted in 36 municipalities up to 50 thousand inhabitants from Southern Brazil. The sample was composed of 1,760 scholars, selected thorough systematic sampling. Data were collected by means of a structured questionnaire, containing information on socioeconomic status, oral impact on daily activities (OIDP) and Well-Being (Andrews Scale). Poisson Regression was used to conduct the data analyses. Results: Difficulty to smile was almost twice as high for students who did not present well-being, PR = 1.9 (95%CI = 1.30-2.80). In addition, difficulty to speak, PR = 1,57 (95%CI CI = 1,02-2,40), and disconfort to brush the teeth, PR = 1,93 (CI= 1,29-2,91), were also associated to well-being. Difficulty to eat PR = 1,1 (95% CI= 0,75-1,65), was not associated to it. The family average income was the only sociodemographic variable associated to adolescents well-being, PR = 0,65 (95% CI = 0,45-0,96). Conclusion: The results of this study showed the influence of oral health related activities, smile, speak and teeth brush on the well-being of school adolescentes in Rio Grande do Sul state. In addition, they pointed out the Family average income as a protection factor for the well-being of this population.Objetivo: Investigar a relação entre fatores sociodemográficos e o desempenho de atividades relacionadas à função oral, com o bem-estar psicológico em adolescentes escolares. Materiais e Métodos: Estudo transversal, de base escolar, realizado em 36 municípios de até 50 mil habitantes da região sul do Brasil. A amostra foi composta por 1.760 acadêmicos, selecionados por amostragem sistemática completa. Os dados foram coletados por meio de um questionário estruturado, contendo informações sobre situação socioeconômica, impacto oral nas atividades diárias (OIDP) e Bem-Estar (Escala de Andrews). Regressão de Poisson foi usada para conduzir as análises de dados. Resultados: A dificuldade para sorrir foi quase duas vezes maior para os estudantes que não apresentaram bem-estar, RP = 1,9 (IC95% = 1,30-2,80). Além disso, dificuldade para falar, RP = 1,57 (IC95% IC = 1,02-2,40) e desconforto para escovar os dentes, RP = 1,93 (IC = 1,29-2,91), também foram associados ao bem-estar. A dificuldade para comer PR = 1,1 (IC 95% = 0,75-1,65), não foi associada a ele. A renda familiar média foi a única variável sociodemográfica associada ao bem-estar dos adolescentes, RP = 0,65 (IC95% = 0,45-0,96). Conclusão: Os resultados deste estudo mostraram a influência das atividades relacionadas à saúde bucal, sorriso, fala e dentes no bem-estar de adolescentes escolares no estado do Rio Grande do Sul. Além disso, apontaram a renda média da família como fator de proteção para o bem-estar dessa população