ABSTRACT
The aim of this study is the utilization of human medical CT images to quantitatively evaluate two sorts of "error-driven" material algorithms, that is, the isotropic and orthotropic algorithms, for bone remodelling. The bone remodelling simulations were implemented by a combination of the finite element (FE) method and the material algorithms, in which the bone material properties and element axes are determined by both loading amplitudes and daily cycles with different weight factor. The simulation results showed that both algorithms produced realistic distribution in bone amount, when compared with the standard from CT data. Moreover, the simulated L-T ratios (the ratio of longitude modulus to transverse modulus) by the orthotropic algorithm were close to the reported results. This study suggests a role for "error-driven" algorithm in bone material prediction in abnormal mechanical environment and holds promise for optimizing implant design as well as developing countermeasures against bone loss due to weightlessness. Furthermore, the quantified methods used in this study can enhance bone remodelling model by optimizing model parameters to gap the discrepancy between the simulation and real data.
ABSTRACT
To investigate the feasibility of application of digital images of the palatal rugae in forensic identification. One hundred patients, consisting of 50 males and 50 females, who received treatment between January 2015 and June 2015 at Shanxi Medical University Stomatological Hospital, China, were included in this study. High-resolution digital image of the palatal rugae was taken from each patient using a digital SLR camera and then processed using a digital image recognition system, including noise reduction, contrast enhancement, image segmentation, feature extraction, edge detection and information matching. Using an MATLAB software system, match results and the time taken by each operator for information matching were recorded. The digital image recognition system assisted in information matching of the palatal rugae. Three oral physicians had a 100% correction rate in information matching. Two other operators failed in formation matching in one or two cases. The time taken by oral physicians for information matching was shorter than that taken by the other two operators. Unique palatal rugae morphology has gradually become a novel marker for forensic identification. Digital images of the palatal rugae morphology contribute to rapider and more accurate forensic identification.
El objetivo fue investigar la viabilidad de la aplicación de imágenes digitales de rugas palatinas para la identificación forense. Se incluyeron 100 pacientes, 50 hombres y 50 mujeres, que recibieron tratamiento entre enero de 2015 y junio de 2015 en el Hospital Odontológico de la Universidad Médica de Shanxi, China. Se tomaron imágenes digitales de alta resolución de las rugas palatinas de cada paciente utilizando una cámara réflex digital y luego se procesaron mediante un sistema de reconocimiento de imagen digital, incluyendo reducción de sonido, mejora del contraste, segmentación de imágenes, extracción de características, detección de márgenes y coincidencia de la información. Mediante el programa MATLAB se registraron los resultados y el tiempo de cada operador para obtener información coincidente, además se utilizó el sistema de reconocimiento de imágenes digitales para hacer coincidirlas con la información de las rugas palatinas. Tres odontólogos informaron una tasa de corrección del 100 % al realizar cruces de información. Otros dos operadores fracasaron en uno o dos casos. El tiempo asignado por los odontólogos para la coincidencia de la información fue menor al de los otros operadores. La morfología especializada de las rugas palatinas se ha convertido gradualmente en un nuevo marcador para la identificación forense. Las imágenes digitales de la morfología de las rugas palatinas contribuyen a una rápida y precisa identificación forense.
Subject(s)
Humans , Male , Female , Forensic Anthropology/methods , Forensic Dentistry/methods , Palate, Hard/anatomy & histologyABSTRACT
Sequence comparison is one of the foundations in bioinformatics, which can be used to study evolutionary relations among the sequences. In this study, a 2D spectrum-like graphical representation of protein sequences is presented based on the hydrophobicity scale of amino acids. The frequencies of amplitudes of 4-subsequences are adopted to characterize a spectrum-like graph, and a 17D vector is used as the descriptor of protein sequence. The χ(2) value of compatibility test is performed. New similarity analysis approach is illustrated on the all protein sequences, which are encoded by the mitochondrion genome of 20 different species. Finally, comparison with the ClustalW method shows the utility of our method.
ABSTRACT
In this paper, a dynamic 3-D graphical representation of protein sequences is introduced based on three physical-chemical properties of amino acids. The coordinates of the graph have direct biological significance, which could reflect the innate structure of the proteins. The information of principal moments of inertia and range of axis coordinate are extracted as a novel mixed descriptor and proposed for the comparison of protein primary sequences. Meanwhile, the Euclidean distance of the normalized descriptor vectors which avoid the influence of the difference in length of protein sequences under consideration is employed as a quantitative measurement of the similarity of proteins. Finally, we take the nine ND5 (NADH dehydrogenase subunit 5) proteins for example and illustrate the effectiveness of our approach.
