Electroencephalogram signal analysis and its research progress in the field of epilepsy treatment / 中华神经科杂志

Epilepsy is a serious chronic neurological disorder that can be detected by analysing the brain signals generated by brain neurons, with electroencephalography (EEG) becoming a key tool in the diagnosis of epilepsy. The application of specific methods for processing and analysing EEG signals is important in exploring the working mechanisms of the brain and in the diagnosis of neurological disorders of the brain. The article describes the application of EEG signals in epilepsy treatment through feature extraction, feature classification and other related analysis methods. The article presents an overview of recent research advances through the use of principal component analysis, independent component analysis, wavelet transform, linear discriminant analysis, support vector machine, artificial neural network and decision tree. It provides some reference for the detection and classification of seizures and future research directions.

Effects of Collagen Fiber Bundle on Mechanical Properties of Articular Cartilage / 医用生物力学

Objective To study the effects of collagen fiber bundle on mechanical properties of articular cartilage, so as to provide references for clinicians to guide the rehabilitation of patients with early cartilage injury. Methods The two-dimensional (2D) numerical model of fiber-reinforced porous viscoelasticity was established, with consideration of the relationship of fiber distribution, elastic modulus, porosity and permeability with cartilage depth. The influences from local fracture of the fiber bundle, the progressive fracture from the surface and the fiber bundle size on mechanical properties of the cartilage were studied, and the maximum principle strain of cartilage matrix was obtained. Results The maximum principal strain of the matrix occurred at a position in middle layer of the cartilage, about upper 1/3 of the cartilage, which was not affected by fiber breakage mode and fiber bundle size. The strain of the cartilage with thicker fiber bundles decreased. Conclusions The middle layer of the cartilage was prone to mechanical damage. The thicker fiber bundle could reduce the maximum principal strain of the matrix. Once the fiber bundle broke, the maximum principal strain of the cartilage matrix with thicker fiber bundle became larger, leading to an easier evolution of the cartilage damage.

Simulación Mediante Elemento Finito de Sistemas Intramedulares Telescópicos para Rehabilitación de Pacientes con Osteogénesis Imperfecta / Simulation by Finite Element Method of Intramedullary Telescopic Systems for Rehabilitation of Patients with Osteogenesis Imperfecta

Resumen En el trabajo se plantea el análisis de diferentes geometrías para un dispositivo intramedular, las cuales ayudan a reducir y evitar la migración, deformación y rotura del implante en tejido óseo afectado con Osteogénesis Imperfecta (OI). Se realizaron diseños en CAD de diferentes prototipos, donde se analizan las propiedades mecánicas en el alma del dispositivo, así como en las roscas distal y proximal de los implantes macho y hembra. Asimismo, se obtuvieron modelos 3D de huesos de un infante afectado con OI para realizar simulaciones mediante elemento finito de la interacción entre el hueso y el dispositivo intramedular. Los resultados muestran que los prototipos propuestos disminuyen la deformación del dispositivo, así como el aumento en la rigidez de la relación hueso-prótesis. Asimismo, las roscas generaron un menor esfuerzo en la unión con el hueso, lo que prevé un menor daño al tejido óseo. El trabajo se limitó al análisis numérico del rediseño de implantes telescópicos intramedulares para afectados con OI. Concluyendo que la geometría semicircular 3/4 de caña, otorga un óptimo resultado en las pruebas realizadas, al tiempo que las roscas ACME proveen una mejor sujeción en las epífisis distal y proximal de los huesos largos.

Abstract In this work we propose the analysis of different geometries for an intramedullary device, which help to reduce and avoid the migration, deformation and rupture of the implant in bone tissue affected with Osteogenesis Imperfecta (OI). Designs of different prototypes were made in CAD, where the mechanical properties in the device's soul are analyzed, as well as in the distal and proximal threads of the male and female implants. Likewise, 3D bone models of an affected infant with OI were obtained to perform finite element simulations of the interaction between the bone and the intramedullary device. The results show that the prototypes proposed decrease the strain of the device, as well as the increase in the stiffnes of the bone-prosthesis relationship. Also, the threads generated less stress in the union with the bone, which provides less damage to the bone tissue. The work was limited to the numerical analysis of the redesign of intramedullary telescopic implants for patients with OI. Concluding that the semicircular geometry 3/4 of cane, gives an optimal result in the tests carried out, while the ACME threads provide a better subjection in the distal and proximal epiphyses of the long bones.

Análise de tensões pelo método dos elementos finitos em implantes dentários com plataforma cone morse / Finite element stress analysis in morse cone platform dental implants

A previsão do comportamento mecânico de implantes dentários inclinados é um fator importante na área odontológica e o Método dos Elementos Finitos (MEF) é considerado uma ferramenta para esse fim. Objetivo: analisar a distribuição de tensões e deslocamentos em implantes cônicos do tipo cone morse com 3,5 mm de diâmetro e pilares com 4,8 mm e 3,8 mm de diâmetro, submetidos a carregamentos de compressão (100 N e 200 N), inclinados a 20º e 45º com base de aço inoxidável e osso cortical via MEF. Materiais e método: utilizaram-se dois modelos tridimensionais de implantes e pilares instalados de forma inclinada a 20º e 45º, os quais foram submetidos a carregamentos de compressão no sentido vertical para baixo (eixo ­ Y). Resultados: as tensões máximas de von Mises apresentaram valores superiores para geometrias com inclinação de 45º e carregamento de 200 N. Foi possível verificar ainda que os resultados para implantes submetidos ao carregamento de 100 N a 45º apresentaram valores superiores (574,16 MPa), quando comparado com dados da literatura, com diferença de 8,7%. O mesmo pôde ser verificado para resultados de deslocamento, onde o conjunto de implantes-pilares com inclinação maior (45º) apresentou maiores valores, quando comparados com implantes-pilares com inclinação menor (20º). Conclusão: foi possível certificar via MEF que as maiores tensões são obtidas para carregamentos com inclinações maiores, sendo que o mesmo ocorre para valores de deslocamento. O MEF demonstrou ser uma alternativa viável na área odontológica para prever o comportamento mecânico de implantes dentários.(AU)

Predicting the mechanical behavior of tilted implants is an important factor in the field of dentistry, and the Finite Element Analysis (FEA) is a tool for such purpose. Objective: To analyze the distribution of stresses and displacements in conical Morse cone implants with 3.5 mm of diameter and abutments with 4.8 mm and 3.8 mm of diameter, subjected to compression loads (100 N and 200 N), tilted at 20º and 45º with stainless steel base material and cortical bone, using FEA. Materials and method: Two three-dimensional models of implants and abutments tilted at 20º and 45º were used, and they were subjected to vertical downward compression loads (Y­axis). Results: Maximum von Mises stresses presented higher values for the 45º inclination and 200 N load. It was also verified that the results for implants subjected to a load of 100 N and implants tilted at 45º presented higher stress values (574.16 MPa) than literature data, with a difference of 8.7%. This was also observed for displacement results, in which implant- abutment assemblies with greater inclination (45º) presented higher values than implant-abutments with smaller inclination (20º). Conclusion: The FEA showed that higher stress values were obtained when compression loads were applied to greater inclinations. This also occurred for displacement results. The FEA represented a viable alternative in the field of dentistry to predict the mechanical behavior of dental implants.(AU)

Effects of Rounding on Prediction of Flow Field and Hemolysis for the FDA Benchmark Blood Pump / 医用生物力学

Objective To investigate the effects of rounding on the prediction of flow field and hemolysis for FDA benchmark blood pumps by using the method of computational fluid dynamics（CFD）. Methods Key properties such as hydraulic characteristics, mean velocity distributions and hemolysis index of FDA benchmark blood pump under three operating conditions were simulated, and the influence of the above simulation result was further compared when the impeller was equipped with or without rounding. Results The rounding of blood pump impeller had impacts on pump head (the maximum percentage difference between the impeller with rounding and without rounding was 57.38%), velocity distributions, which led to a considerable impact on predicted hemolysis levels (the maximum error between the impeller with rounding and without rounding was more than one order of magnitude). Conclusions Impeller with rounding was beneficial for optimization of blood pump performance. The research findings are of great importance for better use of CFD to aid the hemocompatibility design of blood pump.

Advances in Clinical Application of Numerical Study of Ear and Upper Airway / 医用生物力学

Ear and upper airway are portal organs of human body. Because of their fine and narrow structure, the non-invasive research and the effect of clinical diagnosis and treatment in traditional medicine are always unsatisfactory. With the development of computer technology, numerical simulation has become an effective means of auxiliary research. Numerical simulation can reproduce or evaluate the diagnosis and treatment of ear and upper airway diseases, and it is a powerful means to promote the development of basic medicine and technology of clinical diagnosis and treatment. The application of numerical simulation in relationship between the structure and function of ear and upper airway, the influence of diseases on function, the evaluation of clinical diagnosis and treatment technology， as well as the design of related medical devices were reviewed. The clinical application of numerical research in ear and upper airway was prospected, so as to provide references for the future clinical diagnosis and treatment of ear and upper airway.

Hemodynamic Analysis of Stanford Type B Aortic Dissection Based on Computational Fluid Dynamics / 医用生物力学

Objective To analyze the hemodynamic parameters of Stanford type B aortic dissection based on computational fluid dynamics (CFD), so as to make a thorough evaluation of the disease.Methods Based on CTA images of a patient with complex Stanford type B aortic dissection, the three-dimensional model and hemodynamic numerical simulation were carried out to analyze the velocity distribution of flow field and intersecting fracture profile, as well as the wall shear stress. Results The maximum velocity of blood flow at the entry tear and re-entry tear could reach 1.2 m/s and 2 m/s, respectively, providing references for further evaluation on aortic rupture position and prediction of aortic rupture risk. An obvious low wall shear stress zone was formed on false lumen wall near the entry tear, which was consistent with the thrombus position in the patient. Conclusions CFD could effectively analyze the hemodynamic characteristics of complex aortic dissection, obtain the correlation between aortic dissection and wall shear stress at aorta arch and descending aorta, which contributed to guiding clinical assessment of aortic function for preventing the diseases.

Review of research methods on mechanical properties of interventional stent / 医用生物力学

Interventional stents are emerging medical apparatus and instruments which can be implanted into the lesion location to reopen and scaffold the blocked cavities.The ideal stents must have reliable mechanical properties,and the current research methods on mechanical properties of the stents are mainly based on theoreti cal analysis,numerical analysis and experimental test.In this article,all kinds of analytic methods on testing mechanical properties of the stents and their limitations are discussed and summarized in detail,and further research on the stents is prospected as well.

Risk of water surplus in soybean crop on haplic planosol soil in the Central Depression of Rio Grande do Sul State, Brazil / Risco de excesso hídrico para a cultura da soja em planossolo háplico na Depressão Central do Rio Grande do Sul

ABSTRACT: The aim of this study was to identify soybean sowing dates on which there was low water surplus risk. The crop was raised on a Haplic Planosol soil in the Central Depression of Rio Grande do Sul, Brazil. Soybean development simulations and daily water balances were calculated for different sowing dates from August 1968 to July 2012. Water surplus data was subjected to BoxPlot analyses and Scott-Knott tests at a 5% error probability. Exponential, gamma, lognormal, normal and Weibull functions were tested and the best fits to the data were obtained for both subperiods and total cycle. The highest number of fits for the development cycle and subperiods were obtained using the gamma and weibull functions, respectively. For sowing carried out after November 1, there was a low water surplus risk in the sowing-emergence subperiod. The risk of water surplus during the development cycle decreased with the advance of the sowing date.

RESUMO: O objetivo deste trabalho foi identificar as datas de semeadura com menor risco de ocorrência de excesso hídrico para a cultura da soja, em um Planossolo Háplico na Depressão Central do Rio Grande do Sul. A simulação do desenvolvimento da soja e o balanço hídrico sequencial diário foram realizados para diferentes datas de semeadura em cada ano do período de agosto de 1968 a julho de 2012. Os dados dos dias de excesso hídrico, obtidos para o ciclo da cultura, foram submetidos à análise BoxPlot e teste de Scott-Knott a 5% de probabilidade de erro. Foram testadas as funções exponencial, gama, lognormal, normal e weibull, verificando-se a de melhor ajuste aos dados obtidos para os subperíodos e ciclo total. O maior número de ajustes para o ciclo de desenvolvimento e para os subperíodos foram obtidos para as funções gama e weibull, respectivamente. As semeaduras, realizadas após o dia primeiro de novembro, apresentam menor risco de ocorrência de excesso hídrico no subperíodo semeadura-emergência. O risco de ocorrência de excesso hídrico para o ciclo de desenvolvimento é decrescente, conforme o avanço da data de semeadura.

Review of research methods on mechanical properties of interventional stent / 医用生物力学

Interventional stents are emerging medical apparatus and instruments which can be implanted into the lesion location to reopen and scaffold the blocked cavities. The ideal stents must have reliable mechanical properties, and the current research methods on mechanical properties of the stents are mainly based on theoretical analysis, numerical analysis and experimental test. In this article, all kinds of analytic methods on testing mechanical properties of the stents and their limitations are discussed and summarized in detail, and further research on the stents is prospected as well.

Numerical analysis on deposition of particulate matters in respiratory tract / 医用生物力学

Objective To study the regular pattern of inhalational particulate matter deposition in respiratory tract and its influencing factors during breathing by numerical simulation method. Methods Three-dimensional finite element model of normal human respiratory tract was established to simulate the airflow distributions in respiratory tract during inspiration. The particles were released at the entrance of nose or mouth to simulate the deposition process of suspended particles by inhaled airflow in respiratory tract. Different parameters such as particle diameter, particle density and flow rate of air volume were used for comparative analysis to investigate their functions as influencing factors when particle deposition happened in respiratory tract. Results The particles were mainly deposited in nasal threshold, nasal middle airway, nasopharynx, and bronchial inner wall of respiratory tract. The particle deposition rate increased with the parameters of particle diameter, particle density and air volume flow rate increasing. The influence of different parameters on the deposition rate was not the same. Conclusions The particle is mainly deposited at the site with complex geometry or at the position where path direction changes violently. Particle diameter, density and breathing airflow rate will affect the deposition rate in respiratory tract. These research findings will provide numerical references for the clinical assessment on risk of respiratory diseases caused by air pollution.

Numerical simulation of intranasal airlfow ifeld / 中国耳鼻咽喉头颈外科

[ABSTRACT]OBJECTIVETo explore the basic characters of the airflow-field in Chinese people's nasal cavity by computational fluid dynamics.METHODSThe three-dimensional, finite-element mesh were developed from Spiral CT imaging scans of nose of the 40 healthy Chinese people. Given the following spatial boundaries of the flow field: no-slip condition was imposed at the surface of the nasal airway walls; a standard atmosphere pressure condition was established at the inlet; a velocity vector was specified at the outlet (nasopharynx), which was obtained under the condition of aspiratory flow rate (12 L/min), the full Navier-Stokes and continuity equations were solved to obtain the airflow pattern.RESULTS1. The airflow passed mainly through left or right side of the nasal airway in the whole 40 cases (left 33, right 7),and the volume of air through the main-side is (320±28) ml while non-main-side (180±45) ml. 2. Airflow velocity: airflow of anterior nostrils, internal nostrils, the middle and inferior parts of the total meatus in the main-side were (5.01±2.12) m/s, (7.00±1.75) m/s, (5.08±1.55) m/s, (4.12±1.40) m/s respectively, and those in non-main-side were (2.01±0.94) m/s, (2.40±0.34) m/s, (1.99±1.0) m/s, (2.01±0.65) m/s respectively, which differences between the both sides were of statistical significance (allP0.05); 3. The airflow form appeared to be linear in the middle and inferior parts of the nasal cavity. 4. Velocity in maxillary sinus cavity was almost 0 m/s.CONCLUSIONThe airflow passes mainly through the middle and inferior parts of the meatus with higher velocity in laminar form and airflow of middle meatus, inferior meatus and olfactory cleft are low and the velocity were slow. Besides, airflow in maxillary sinus cavity diffuses free mainly.

Structure design and calculation analysis for double gasbags based on body weight support treadmill training / 医用生物力学

Objective To develop a double-gasbag weight loss equipment based on body weight support treadmill training (BWSTT)，and analyze the reasonability of the structure design. Methods The mathematical model of double gasbags in the process of air inflation was established, and the 3D model of double gasbags was established and meshed using Gambit; the analog computation for gas flow of the gasbag was conducted using Fluent; normal subjects with body weight below 80 kg were selected for clinical experiments based on designing and roughing of the prototype. Results The inflation time of double gasbags was 16.9 s and the maximum weight loss percentage was 90%; the pressure inside double gasbags was 2 kPa, and the relationship between the weight loss percentage and inside pressure of the gasbag was obtained by clinical experiments, which verified the reasonability of the gasbag structure. Conclusions The double-gasbag structure can meet the requirements of weigh loss training, which provides an effective weight loss support method and a feasible structural design for patients with lower limb dysfunction during rehabilitation training.

Oral administration of curcumin (Curcuma longa) can attenuate the neutrophil inflammatory response in zymosan-induced arthritis in rats

PURPOSE: To evaluate the effect of curcumin in the acute phase of zymosan-induced arthritis. METHODS: Twenty-eight male rats were subjected to intra-articular infiltration of zymosan of both knees and, in four the infiltration was made with saline. The animals were divided into five groups second received every six hours by gavage: corn oil by (positive and negative control); curcumin (100 mg/kg); prednisone 1 mg/kg/day; prednisone 8 mg/kg. All animals were sacrificed after six, 12, 24 and 48 hours of the infiltration. The knees were removed for evaluation of neutrophil infiltration. The number of neutrophils was counted by computer-assisted analysis of the images. The neutrophil infiltrate was stratified into four grades: 0 = normal; + = mild; ++/+++ = moderate; > ++++ = severe. The results were compared using the Mann-Whitney test and the variance by Kruskal-Wallis test adopting a significance level of 5% (p<0.05). RESULTS: Curcumin reduces inflammatory activity in the first six hours after zymosan-induced arthritis when compared to saline (p<0.01). This was also observed in animals subjected to administration of prednisone (1 mg/kg) and those treated with prednisone (8 mg/kg). Curcumin was more effective than lower doses of prednisone in the first six hours after induction of the arthritis. After 12, 24 and 48 hours, curcumin does not have the same anti-inflammatory effects when compared to prednisone. After 48 hours, prednisone is more effective than curcumin in reducing the inflammatory infiltrate regardless of the dose of prednisone used. CONCLUSION: Oral administration of curcumin reduces inflammation in the first six hours after experimentally zymosan-induced arthritis. .

Comportamento mecânico de sistemas prótese/implante em região anterior de maxila: análise pelo método dos elementos finitos e interferometria holográfica / Mechanical behavior of prosthesis/implant systems in the anterior maxilla: analysis by finite element method and holographic interferometry

A proposta deste estudo foi analisar, por meio do método de elementos finitos (MEF), o comportamento mecânico das estruturas envolvidas em uma reabilitação implanto suportada de 4 elementos na região anterior de maxila, utilizando apenas 2 implantes, variando os posicionamentos dos implantes e o tipo de conexão protética (hexágono externo, hexágono interno e cone-Morse) e ainda validar metodologia de análise computacional por meio da interferometria holográfica, uma técnica experimental. Modelos tridimensionais baseados em um banco de tomografias computadorizadas foram criados para todas as situações estudadas (Implantes nos Incisivos Laterais - IL; Implantes nos Incisivos Centrais - IC e Implante no Incisivo Central e Incisivo Lateral - ILIC). Uma carga equivalente à 150N foi aplicada a 45° na região de cíngulo de cada elemento dentário. Para a validação da metodologia de elementos finitos por meio da interferometria holográfica, criou-se um modelo prototipado com as mesmas situações estudadas e comparou-se os deslocamentos direcionais resultantes da aplicação de 3 intensidades de força. Como resultado foi observado: o menor deslocamento da estrutura protética e maior deslocamento na estrutura óssea no grupo IC. No tecido ósseo, a tensão de von Misses localiza-se predominantemente na região cortical. O valor máximo de tensão de von Misses foi observado no implante vizinho ao cantilever no grupo ILIC. Na conexão cone Morse, o parafuso protético mostrou metade da tensão de von Misses em relação a conexão hexágono interno e hexágono externo. Comparando-se os deslocamentos direcionais nas duas metodologias, verificou-se que havia uma correlação positiva entre os resultados, porém os valores obtidos experimentalmente eram superiores aos do modelo computacional. Pode-se concluir que o posicionamento dos implantes e o tipo de conexão protética em reabilitação anterior de maxila influenciam a distribuição e intensidade de tensão/deformação nas estruturas da prótese implanto-suportada e ainda que o MEF pode ser usado como uma eficiente técnica para a análise de tensão, deformação e deslocamento quando utilizada com modelos validados experimentalmente

The purpose of this study was to analyze, by finite element method (FEM), the mechanical behavior of structures involved in an implant supported rehabilitation of 4 elements in the anterior maxilla, using only 2 implants, varying the placements of the implants and prosthetic connection types (external hexagon, internal hexagon and Morse taper) Moreover to validate the methodology of MEF by holographic interferometry, an experimental technique. Three-dimensional models based on a database CT scans were created for all situations studied (Implants in Lateral Incisors - IL; Implants in Central Incisors IC and Implant in Central e Lateral Incisor - ILIC). An equivalent load of150N was applied at 45° in the cingulum of each tooth. To validate the finite element method by Holographic Interferometry, a prototyped model was created with the same situations studied and compared the directional displacements, resulting from the application of the 3 intensities of force. As results it was observed: the lowest prosthetic displacement structure and greater displacement in the bone structure in the IC group. In bone tissue, the von Mises stress is located predominantly in the cortical region. The maximum value of von Mises stress was observed in the implant neighboring to cantilever in the group ILIC. In Morse taper connection, the prosthetic screw showed half the von Misses stress in relation to internal and external hexagon connection. Comparing the directional displacement in both methodologies, an positive correlation between the results was found, although the experimentally values obtained were higher than those of the computational model. It can be concluded that the placement of implants and prosthetic connection type have influence in the intensity and distribution of stress/strain on the implant-supported rehabilitation of anterior maxilla and moreover the FEM can be used as an efficient technique for analysis of stress, strain and displacement when used with experimentally validated models

Comportamento mecânico de sistemas prótese/implante em região dos elementos finitos e interferometria holográfica / Mechanical behavior of prosthesis / implant systems in the anterior maxilla: analysis by finite element method and holographic interferometry

A proposta deste estudo foi analisar, por meio do método de elementos finitos (MEF), o comportamento mecânico das estruturas envolvidas em uma reabilitação implanto suportada de 4 elementos na região anterior de maxila, utilizando apenas 2 implantes, variando os posicionamentos dos implantes e o tipo de conexão protética (hexágono externo, hexágono interno e cone-Morse) e ainda validar metodologia de análise computacional por meio da interferometria holográfica, uma técnica experimental. Modelos tridimensionais baseados em um banco de tomografias computadorizadas foram criados para todas as situações estudadas (Implantes nos Incisivos Laterais - IL; Implantes nos Incisivos Centrais - IC e Implante no Incisivo Central e Incisivo Lateral - ILIC). Uma carga equivalente à 150N foi aplicada a 45° na região de cíngulo de cada elemento dentário. Para a validação da metodologia de elementos finitos por meio da interferometria holográfica, criou-se um modelo prototipado com as mesmas situações estudadas e comparou-se os deslocamentos direcionais resultantes da aplicação de 3 intensidades de força. Como resultado foi observado: o menor deslocamento da estrutura protética e maior deslocamento na estrutura óssea no grupo IC. No tecido ósseo, a tensão de von Misses localiza-se predominantemente na região cortical. O valor máximo de tensão de von Misses foi observado no implante vizinho ao cantilever no grupo ILIC. Na conexão cone Morse, o parafuso protético mostrou metade da tensão de von Misses em relação a conexão hexágono interno e hexágono externo. Comparando-se os deslocamentos direcionais nas duas metodologias, verificou-se que havia uma correlação positiva entre os resultados, porém os valores obtidos experimentalmente eram superiores aos do modelo computacional. Pode-se concluir...

The purpose of this study was to analyze, by finite element method (FEM), the mechanical behavior of structures involved in an implant supported rehabilitation of 4 elements in the anterior maxilla, using only 2 implants, varying the placements of the implants and prosthetic connection types (external hexagon, internal hexagon and Morse taper) Moreover to validate the methodology of MEF by holographic interferometry, an experimental technique. Three-dimensional models based on a database CT scans were created for all situations studied (Implants in Lateral Incisors - IL; Implants in Central Incisors IC and Implant in Central e Lateral Incisor - ILIC). An equivalent load of150N was applied at 45° in the cingulum of each tooth. To validate the finite element method by Holographic Interferometry, a prototyped model was created with the same situations studied and compared the directional displacements, resulting from the application of the 3 intensities of force. As results it was observed: the lowest prosthetic displacement structure and greater displacement in the bone structure in the IC group. In bone tissue, the von Mises stress is located predominantly in the cortical region. The maximum value of von Mises stress was observed in the implant neighboring to cantilever in the group ILIC. In Morse taper connection, the prosthetic screw showed half the von Misses stress in relation to internal and external hexagon connection. Comparing the directional displacement in both methodologies, an positive correlation between the results was found, although the experimentally values obtained were higher than those of the computational model. It can be concluded that the placement of implants and prosthetic connection type have influence in the intensity and distribution of stress/strain on the implant-supported rehabilitation of anterior...

Uso de técnicas moleculares na detecção de DNA parasitário e no estudo da variabilidade genética em diferentes fragmentos teciduais de cães naturalmente infectados por Leishmania (Viannia) braziliensis / Use of molecular techniques in parasite DNA detection and genetic variability study in different tissue fragments from naturally infected dogs by Leishmania (Viannia) braziliensis

A leishmaniose tegumentar americana (LTA), em cães, costuma estar associada à resposta humoral baixa ou mesmo negativa, o que inviabiliza os métodos sorológicos convencionais, como ferramenta única no diagnóstico. [...] Métodos convencionais de diagnóstico parasitológico, não têm sido capazes de detectar a presença do parasito em outros sítios anatômicos diferentes da lesão cutânea, em cães naturalmente infectados por Leishmania (Viannia) braziliensis. Diante dos questionamentos sobre o papel do cão doméstico no ciclo de transmissão da LTA e sobre o valor de métodos diagnósticos aplicados na rotina, principalmente em áreas de sobreposição da forma tegumentar e visceral, faz-se necessário a avaliação desses animais sob diversos aspectos. O presente estudo teve como objetivo empregar a PCR específica associada à hibridização molecular e a técnica da reação em cadeia da polimerase com primer único em condições de baixa estringência (LSSP-PCR) visando detectar a presença de DNA parasitário e investigar a variabilidade genética de populações parasitárias presentes em diferentes tecidos de cães naturalmente infectados por L. (V.) braziliensis. Os animais foram selecionados entre os cães sororeatores para Leishmania procedentes de cidades do estado do Rio de Janeiro e encaminhados para eutanásia ao Laboratório de Pesquisa Clínica em Dermatozoonoses em Animais Domésticos do Instituto de Pesquisa Clínica Evandro Chagas da Fundação Oswaldo Cruz. Durante a necropsia, foram obtidas amostras de lesão cutânea, pele íntegra (região escapular e abdominal), baço, fígado e linfonodos (poplíteo e cervical)...

In dogs, American tegumentary leishmaniasis (ATL) is usually associated to a low humoral responseor even to negative results which turns not unfeasible the conventional serological methods. [...] Conventional methods ofparasitological diagnosis have failed to detect the presence of the parasite anatomic sites others thanthe cutaneous lesion, in dogs naturally infected by Leishmania (Viannia) braziliensis. Regarding thequestions on the rule of domestic dogs in the transmission cycle of ATL and, on the applicability ofdiagnostic methods mainly in areas where both visceral and tegumentary disease are found, theevaluation of these animals under different aspects is needed. The objective of this project is to applyspecific PCR assays associated to molecular hybridization and the technique of Low-StringencySpecific-Single Primer – PCR (LSSP-PCR) in order to detect the presence of parasite DNA andevaluate the genetic variability of parasite populations found in different tissues of dogs naturallyinfected by Leishmania (V.) braziliensis...

Diversity and gradients in cedar forests on Taurus mountain range (Turkey).

Cedrus libani forests have been under anthropogenic pressure for thousands of years. The unattainable topography of the Taurus mountain range (Southern Anatolia) has prevented cedar in this region from being extirpated, in contrast to its other distribution areas in Syria and Lebanon. Numerical analyses of relev?confirmed the individuality of associations, as well as the division of C. libani forests into two ecological and floristically different groups/alliances (Abieti-Cedrion and Lonicero-Cedrion). Abieti-Cedrion is distributed in the middle and eastern Taurus whereas Lonicero-Cedrion appears in the Western Taurus. The main gradients of C. libani forests were detected. It was noticed that the distribution and floristic composition of C. libani forests is strongly affected by the geographical factors. Topographical factors are also influential on their distribution. C. libani forests are fundemantal components of the Mediterranean phytogeographical region and floral elements, but under more continental conditions, where the influence of the Mediterranean climate decreased, the proportion of Iran-Turanian and Euro-Siberian floral elements increase, especially towards the east and north, as well at higher altitudes and on steeper sites.

Femoral stem-bone interface analysis of logical uncemented stem / Análise numérica do comportamento biomecânico da haste femoral não-cimentada Logical

This paper evaluates the mechanical behavior of an uncemented hip stem using finite element analysis. The analysis is focused on the stem-bone interaction which is assessed by simulation of distinct conditions encountered daily on orthopedic practice of hip implants. Logical uncemented femoral stem was used in this work. Three distinct conditions have been modeled: a) exposed neck with fully embedded fins, b) partially exposed anti-rotational fins and c) fully exposed fins, representing real femoral hip conditions. Anthropometric variations and different angulations for the stem neck were investigated for typical body weight of populations submitted to implants. The ratio of mobilized stress to yield stress is shown to be lower than 55% indicating a safety factor against stem failure. Although small displacements are observed in all conditions, the displacement increases with the increase of both the length of exposed fins and the magnitude of applied forces. Even for the extreme condition of fully exposed fins, the prostheses will support the working loads, and the risk of bone fracture still has a safety factor. Stresses and displacements change considerably with neck angulations suggesting that anthropometric variations should be considered in the future to optimize prostheses performance. Numerical analysis of the used uncemented femoral stem demonstrated that small stresses and strains are generated under working load conditions indicating that a proper factor of safety is obtained for the static conditions tested in the present study.

A presente pesquisa avalia o comportamento mecânico da haste femoral não-cimentada Logical através de elementos finitos. Foram analisadas diferentes condições de contorno encontradas na prática ortopédica: a) apenas o colo exposto; b) com as aletas anti-rotatórias parcialmente expostas; e c) com as aletas totalmente expostas. Variações antropométricas foram consideradas pelas diferentes angulações de colo propostas e através de diferentes cargas aplicadas. A haste apresentou um bom coeficiente de segurança. Embora pequenos deslocamentos sejam observados em todas as condições, existe um maior deslocamento com o aumento da exposição das aletas da prótese. Mesmo para a condição extrema com as aletas totalmente expostas, a prótese suporta as cargas de trabalho e ainda há um bom fator de segurança. Tensões e deslocamentos se modificam consideravelmente com as diferentes angulações propostas para o colo, sugerindo que as variações antropométricas devam ser consideradas no futuro para otimizar o desempenho da prótese.

Numerical analysis on drug deposition from drug eluting stents in curved artery / 医用生物力学

Objective To investigate the influence of the location of drug release and the stent spacing on drug deposition in curved artery walls. Method 2D curved artery and strut models were employed to carry out a numerical investigation on drug deposition under different drug release surfaces or stent spacing ( 1 strut length, 3 strut lengths, 7 strut lengths ). The results were compared with those in a straight artery. Results The drug depositions produced by four different surfaces of a single strut were quite different. Compared with the curved artery, the superiority of drug release from the top surface of the straight artery was reduced, while the weakness of drug release from proximal surface was substantially increased. There was no significant change for drug release from the distal surface. The average drug concentration increased with interstrut spacing increasing, but the percentage increase was less than that in the straight artery. Concentration differences were observed between the inside and outside of the curved artery, which on the outside showed much lower. Conclusions The local flow alteration, the drug release location and the stent spacing have significant effects on drug deposition in a curved artery and the result is obviously different from that in a straight artery.