Three-dimensional Fluid-Structure Interaction Model of Venous Valve Based on Immersed Boundary/Finite Element Method / 医用生物力学

Objective To explore the dynamic process of fluid-structure interaction(FSI)between venous blood and valves and the physiological mechanism that guarantees unidirectional blood reflux back to the heart.Methods A three-dimensional(3D)numerical model of the venous system was established using the immersed boundary/finite element method.In the simulation,information from medical images of human lower-extremity veins and the anatomical structure and size of the bovine great saphenous vein were applied.Moreover,a hyperelastic constitutive model was used to describe the incompressible,nonlinear,and hyperelastic mechanical responses of the venous valve under physiological conditions.Results The simulations visualized the process of venous blood transport and the function of venous valves in preventing reflux.The periodic characteristics of venous valve motion and blood flow were reproduced,and important physiological data during the entire cardiac cycle were discussed and quantified,including the pressure,velocity,and flow rate of venous blood;opening area of the venous valve;and stress and strain distributions on the valve surface.Conclusions The 3D FSI model numerically reproduces the physiological dynamic process within veins and potentially provides important references and guidance for revealing the pathological mechanism of venous diseases.

Research of Building 3D Model in External Fixator for Proximal Femoral Fracture Based on Locking Plate Shape / 中国医疗器械杂志

The software of 3D-Modeling(UG NX 10.0) was used to design a new external fixator model for proximal femoral fracture, and fresh femoral cadaver specimens were used to simulate experimental operation. The results showed that the external fixator designed with the proximal femoral locking plate shape can improve the accuracy of Kirschner wire penetration into the femoral neck, reduce fluoroscopic and soft tissue incision injuries, and make a good stability and is easy to operate, which has a certain value for patients with proximal femoral fracture, such as intolerant surgery and poor physical condition.

Toxicity comparison of psoralen in 2D /3D hepatocyte models and its effect on mitochondrial fusion and fission / 中国药理学通报

Aim To evaluate and compare the toxicity of psoralen on two-dimensional(2D)and three-dimensional(3D)cultured human hepatocyte HepG2 models. Methods The 3D cell model of HepG2 cells was constructed by low adsorption U-shaped bottom porous plate method. After treated with psoralen for 24 hours, the cell viabilities of 2D and 3D HepG2 cells were detected by CCK-8 assay, LDH leakage was detected by kit, and the mitochondrial membrane potential was detected by TMRM staining. The effect of psoralen on the mRNA of mitochondrial fusion-fission proteins DRP1, Mfn-2 and OPA1 was detected by Q-PCR. Results 3D model maintained a high level of albumin and urea secretion for a long time. And the expression levels of CYP1A2, CYP2E1, CYP3A4 and UGT1A1 in 3D model were higher than those in 2D model. In 3D model lower concentrations of psoralen showed a significant decrease in cell viability, a significant increase in LDH leakage, and a decrease in mitochondrial membrane potential. Q-PCR results showed that psoralen induced a marked increase in the expression of mitochondrial fission protein DRP1, while a significant decrease in mitochondrial fusion protein OPA1. Conclusions A 3D HepG2 cell model is successfully constructed and applied to the evaluation of psoralen hepatotoxicity; the 3D cell culture model is more sensitive to psoralen toxicity, and mitochondria may play a key role in psoralen-induced cell damage.

Impact of three dimensional printing in orthopedics / 《全球健康杂志（英文）》

The primary objective of this article is to explore effects of latest development in the area of three dimensional(3D) printing & to assess its abilities,and further undertake helpful reporting.Here the focus is to assess ad-vantages of 3D printing in orthopedics and analyze how 3D printed models help solve complex 3D orthopedics distortions.This study identified that 3D models manufactured by 3D printing models reduce medical parts de-velopment cost and surgical planning time.Integrating 3D printing with orthopaedics helps in understanding the conditions of problems and achieving the operation successfully.This technology can enable doctors/surgeons to design,produce,recreate and plan operations more accurately,carefully,and economically.3D models can assist specialists with a visual comprehension of the patient-particular pathology and life structures.Innovation in 3D printing initiated a scaffold for the virtual outline and execution of medical procedures.This research proposes the utilisation of 3D printers as an elective procedure for the fabrication of parts.It empowers surgeons/patients for better training,education and research.In the future,there is a foreseeable expansion of additive manufacturing in orthopedics.

Accuracy and precision of measurements performed on three-dimensional printed pelvises when compared to computed tomography measurements

The preoperative contouring of plates decreases the duration of surgery and improves the quality of the reduction of pelvic fractures. Patient-tailored three-dimensionally printed pelvises might be an interesting tool for achieving that purpose. Currently, no study has evaluated the accuracy of measurements performed on three-dimensional printed models in comparison with computed tomography data for complex bones, such as the pelvis. This study examined whether the measurements obtained on pelvises printed using dual-material fused deposition modeling technology are not significantly different from those obtained on computed tomography images. The computed tomography images of the pelvic region from 10 dogs were used to produce three-dimensionally printed models with a dual-material fused deposition-modeling process. Four segments were measured on both three-dimensionally printed models and computed tomography images. The measurements were performed by three observers and repeated twice. Concordance correlation coefficients were used to assess the precision and accuracy of the measurements as well as evaluate the agreement between the methods. The accuracy of measurements between the methods was > 0.99 for all measurements. The precision was almost perfect for AE (0.996), substantial for BD and BC (0.963 and 0.958, respectively), and moderate for CD (0.912). These results indicate that, despite some minor variations, the measurements performed on printed models reproduced the computed tomography data reliably.

La enseñanza práctica en fonoaudiología a través de modelos tridimensionales: una alternativa prometedora / Theoretical-practical teaching in speech-language pathology through three-dimensional models: a promising alternative

El análisis de cuestionarios respondidos por alumnos de la disciplina Sistemas Sensoriales del curso de Fonoaudiología mostró que había dificultades para entender la histología de las regiones anatómicas del oído. Se estableció que la compresión de la histología demandaba una actividad didáctica complementaria. Por ello, se decidió crear una clase teórico-práctica diferenciada (CTP) usando un modelo tridimensional (3D) del oído humano y preparaciones histológicas de sus regiones. El modelo es una réplica anatómica muy aumentada del oído humano que permite la manipulación exploratoria de modo más eficaz que con piezas anatómicas clásicas. La CTP fue implementada en los dos semestres de 2014. La evaluación de la CTP incluyó un cuestionario de opiniones, más un cuaderno de actividades. Los resultados mostraron medias finales de mejores desempeños en ese año respecto al 2013, donde no fue dada este tipo de clase teórico-práctica. Se concluye que la CTP, asociada al modelo tridimensional y las explicaciones teóricas-prácticas de las preparaciones histológicas, permitió una mejor comprensión del contenido enseñado e introdujo una metodología más eficiente para el proceso de enseñanza-aprendizaje de un tema tan complejo así como importante para la formación académica de los estudiantes de Fonoaudiología. Adicionalmente, a partir de esta experiencia teórico-práctica se ha demostrado, una vez más, la importancia de la relación personal y profesional entre el profesor, preparador estudiantil y los alumnos para la calidad del trabajo académico.

We designed a differentiated theoretical-practical class (CTP) after analyzing questionnaires (Qs) answered by Speech-therapy students that attended the course "Sensory Systems". The Qs showed difficulties related with understanding the practical histology of the sensory systems, as well as problems to correlate it with the learning of the anatomy. We therefore established the to implement an auxiliary didactic activity (CTP). We used a three-dimensional model (3D) AS-001, of the University Extension Project (3D Museum). AS-001, is an enlarged anatomical replica of the human ear which is much more efficient for exploratory manipulation much than anatomical modeling. The assessment of CTP included a questionnaire and a notebook of activities. The CTP was implemented in both semesters during the year 2014. Results showed improvements when compared to 2013's data, when this type of theoretical-practical contents were not implemented. We conclude that the association of the three -dimensional model along with histological analysis of the parts of the ear effectively improved students' understanding of the subject. We therefore consider that CTP is a suitable methodology for the teaching-learning process of a complex, important subject for the academic training of Speech-therapy undergraduate students. Our experience allowed us to determine how important the personal and professional relationship between teachers and students is to improve academic work.

Toxicity testing of four silver nanoparticle-coated dental castings in 3-D LO2 cell cultures / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

To address the controversial issue of the toxicity of dental alloys and silver nanoparticles in medical applications, an in vivo-like LO2 3-D model was constructed within polyvinylidene fluoride hollow fiber materials to mimic the microenvironment of liver tissue. The use of microscopy methods and the measurement of liver-specific functions optimized the model for best cell performances and also proved the superiority of the 3-D LO2 model when compared with the traditional monolayer model. Toxicity tests were conducted using the newly constructed model, finding that four dental castings coated with silver nanoparticles were toxic to human hepatocytes after cell viability assays. In general, the toxicity of both the castings and the coated silver nanoparticles aggravated as time increased, yet the nanoparticles attenuated the general toxicity by preventing metal ion release, especially at high concentrations.

Effect of NSC23766 and Y-27632 on invasion and migration of malignant glioma cells and integrin expression based on 3D hydrogel models / 中华神经医学杂志

Objective To observe the changes of invasion and migration patterns and integrin expression of malignant glioma cells when Rac and Rho pathways are suppressed,respectively,in 3D hydrogel.Methods Liposome mediated pCMVLifeAct-TagGFP2 plasmids were transfected into glioma U87 cells,and then,these cells were divided into NSC23766 treatment group,Y-27632 treatment group,NSC23766 and Y-27632 combined treatment group,and control group.The three treatment groups were added NSC23766 (100 nmol/mL),Y-27632 (10 nmol/mL),100 nmol/mL NSC23766 and 10 nmol/mL Y-27632,respectively;the cells in the control group were added the same amount of medium.Cells were cultured in hydrogel;the composition of round cells,spindle cells and the mesenchymal and amoeboid cell movement transition were observed under confocal microscopy.The hydrogels of each group were infused into the microslide,and the cell chemotaxis effect were recorded and the cell movement velocities and distances were calculated in the living cell workstation.Immunofluorescence was used to observe the alternation ofintegrin expression.Results U87 cells cultured in 3D hydrogel exhibited spindle-like and round-like shapes,corresponding to mesenchymal and amoeboid cell movement.As compared with that in the control group,the proportion of round cells in the NSC23766 treatment group was significantly higher,and that of spindle cells in the Y-27632 treatment group was significantly higher (P＜0.05).The conversion rate ofmesenchymal-amoeboid transition was 50.0％ in NSC23766 treatment group and amoeboid mesenchymal transition was 42.8％ in Y-27632 treatment group as compared with that in the control group,with significant differences (P＜0.05).The velocity and distance of cells cultured in 3D hydrogel decreased orderly in NSC23766 treatment group,control group,Y-27632 treatment group and combined treatment group in chemotaxis test.The immunofluorescence test showed that integrin expression in the Y-27632 treatment group was significantly higher than that in the other three groups,and that in the control group was statistically higher than that in the NSC23766 treatment group and combined treatment group (P＜0.05).Conclusions 3D hydrogel can be used as a favorable substrate for cell culture.The combination targeted inhabitation of Rac 1 and RohA pathways provides theoretical basis for anti-invasion treatment against glioma.

Application of visible simulation surgery in the typeⅡB odontoid fractures / 局解手术学杂志

Objective Through the exploration of the reality technology to find the treatment of type Ⅱ odontoid fractures in anterior fixation of odontoid fractures with hollow screw .Methods Based on 64 row spiral CT continuous 2-dimensional images of akull ,atlas and axis were reconstructed by the Mimics software ,Mimics software reconstruction atlas ,the atlantoaxial 3D visualization structure in Mimics, simulated surgery was carried out in the MedCAD .Results The structure of three-dimensional reconstruction image was clear ,structure of hollow screw into pin-point was accurate in virtual simulation surgery ,the screw path is correct .Conclusion Mimics Software has great val-ues in the diagnosis of odontoid fractures ,preoperative risk evaluation ,place the hollow screw and clinical teaching ,which provides an objec-tive basis for choice of treatment program .

Response of aerobic rice to Piriformospora indica.

Rice cultivation under aerobic condition not only saves water but also opens up a splendid scope for effective application of beneficial root symbionts in rice crop unlike conventional puddled rice cultivation where water logged condition acts as constraint for easy proliferation of various beneficial soil microorganisms like arbuscular mycorrhizal (AM) fungi. Keeping these in view, an in silico investigation were carried out to explore the interaction of hydrogen phosphate with phosphate transporter protein (PTP) from P. indica. This was followed by greenhouse investigation to study the response of aerobic rice to Glomus fasciculatum, a conventional P biofertilizer and P. indica, an alternative to AM fungi. Computational studies using ClustalW tool revealed several conserved motifs between the phosphate transporters from Piriformospora indica and 8 other Glomus species. The 3D model of PTP from P.indica resembling “Mayan temple” was successfully docked onto hydrogen phosphate, indicating the affinity of this protein for inorganic phosphorus. Greenhouse studies revealed inoculation of aerobic rice either with P. indica, G. fasciculatum or both significantly enhanced the plant growth, biomass and yield with higher NPK, chlorophyll and sugar compared to uninoculated ones, P. indica inoculated plants being superior. A significantly enhanced activity of acid phosphatase and alkaline phosphatase were noticed in the rhizosphere soil of rice plants inoculated either with P. indica, G. fasciculatum or both, contributing to higher P uptake. Further, inoculation of aerobic rice plants with P. indica proved to be a better choice as a potential biofertilizer over mycorrhiza.

Registration for 3D model of human atlas based on vertex information / 医用生物力学

Objective To develop a registration method for 3D human atlas models by using geometric information of the vertices so as to lay a foundation for statistical modeling of atlas. Methods Based on CT images of the normal human, thirty 3D models of human atlases were created and marked by the manual selected points, including 1 standard module, 20 training sets and 9 testing samples. The training sets were first registered with the standard module, including calculation on geometric information of the individual vertex and optimization process of weight coefficients in the registration models. By minimizing the energy function defined with the Euclidean distances between the automatic registered points and the manual selected points in training sets, the optimized weight coefficients could be obtained. The testing samples were then registered with the standard module to calculate the Euclidean distances between the automatic registered points and the manual selected points. The results were then compared with the training sets to evaluate the stability of the registration method. Results The registration function and the corresponding optimized weight coefficients were obtained, and the average errors for the training sets and testing samples were 1.983 mm and 2.045 mm, respectively. Further statistical analysis showed that there were no obvious differences in the error distributions among the training sets and testing samples. Conclusions The accuracy and stability of the proposed registration method meet the requirement in medical applications, and it can provide automatic registration of points of interest on human atlas models and be used for element classification in statistical modeling.

Remodelado estrcctural y de gap junctions en un modelo 3d de aurícula humana / Strctural remodeeling and of gap junctions in a 3d model of human atrial

Introducción: la fibrilación auricular (AF), es la más común de la arritmia cardiaca sostenida y un factor de riesgo para el accidente cerebro vascular y otras morbilidades, si no es tratada. Estudios epidemiológicos muestran que la AF tiende a perpetuarse con el tiempo, generando cambios electrofisiológicos y anatómicos denominados: remodelados auriculares. Se ha demostrado que estos cambios provocan variaciones de la velocidad de conducción (CV), en el tejido auricular. Objetivo: estudiar el efecto del remodelado de gap junctions en la propagación del potencial de acción, implementando un modelo 3D de aurícula humana altamente realista. Materiales y Métodos: se incorporaron los cambios generados por el remodelado eléctrico a un modelo de potencial de acción (AP) de miocito auricular, acoplado con un modelo tridimensional anatómicamente realista de aurícula humana dilatada. Mediante simulaciones de la propagación del AP en condiciones de remodelado eléctrico y anatómico, y de remodelado de gap junctions, se midieron las ventanas vulnerables de generación de reentradas en la base de las venas pulmonares izquierdas de la aurícula. Resultados: los resultados obtenidos indican que la ventana vulnerable en el remodelado de gap junctions, se desplazó 38 ms con relación al modelo dilatado, lo que nos muestra el impacto de la dilatación con remodelado de gap junction. Conclusiones: el remodelado eléctrico generó una disminución del 70 % en la duración del potencial de acción y una disminución de las velocidades de conducción entre un 14.6 y un 26 %, que fueron medidas en diferentes regiones de la aurícula dilatada. El foco disparado en la base de las venas pulmonares izquierdas, generó un frente de onda que mantiene una actividad reentrante debido a la anatomía subyacente de las venas pulmonares.

Introduction: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and a significant risk factor for cerebrovascular accident and other morbidities if left untreated. Epidemiological studies show that AF tends to persist over time, creating electrophysiological and anatomical changes called atrial remodeling. It has been shown that these changes result in variations in conduction velocity (CV) in the atrial tissue. Objective: to study the effect of remodeling of gap junctions in the propagation of the action potential by implementing a highly realistic 3D human atrial model. Materials and methods: the changes caused by electrical remodeling were incorporated in an atrial myocyte action potential (AP) model coupled with an anatomically realistic three-dimensional model of dilated human atria. Through simulations of the AP spread in variations of anatomical and electrical remodeling and of gap junctions remodeling, vulnerable windows of reentry generation were measured at the base of the atrium left pulmonary veins. Results: the results obtained indicate that vulnerable window in the gap junctions remodeling moved 38 ms in relation with the expanded model which shows the impact of the dilatation gap junction remodeling. Conclusions: the electrical remodeling produced 70% decrease in action potential duration and decreased conduction velocities between 14.6 and 26 %, which were measured in different regions of the dilated atrium. The focus shot at the base of the left pulmonary veins created a wave which maintains a reentering activity due to the underlying anatomy of the pulmonary veins.

The Three-dimensional Finite-Element Simulation of Alternating Electromagnetic Fields for Microcirculation Experiments / 中国医学物理学杂志

Objective: In order to understand temporal and spatial distributions of alternating electromagnetic field (AEMF) of a coil thoroughly, the 3-D finite-element models of this kind of Biomagnetic Fields are established and analyzed for the research on bioeffect of magnetic field on microcirculation. Methods: Designing CAD models, setting boundary conditions, meshing models and obtaining numerical solutions were completed all within Comsol Multiphysics in terms of the theory of electromagnetic field. Results: Axial and radial plot of spatial attenuation rate of the AEMF, which were accordance with measured data, were simulated while the temporal and spatial distributions of AEMF were acquired. Conclusion: Models of 3-D finite-element of this kind of biomagnetic fields which appeared to exactly simulate the real magnetic field were first established systematically, and solved the placing problem of magnetic fields for the research on bioeffect of magnetic field on microcirculation and provided platforms for the simulation of hemodynamic of blood flow in the magnetic field.

3D measurement and analysis on 3D microstructure model for mandible osteotomy aided by computer / 中华显微外科杂志

@#Objective To build a method of mandible 3D model to measure and analysis, then to finish the operation simulation, providing anatomic data to avoiding the complicafious of mandible osteotomy. Methods Using CT data to reconstruct 3D model of mandible with blood vessel and bone, then using Simpleware to measure and analysis, and using Freeform system and an incision method of Boolean to simulation mandible osteotomy safely. Re, tits It was possible to use CT data to rebuild 3D model for 3D measure and analysis for operation simulation. The inferior alveolar artery and never were the main tiasues which went through the madibhilar. The length of mandibular foramen to anterior minus was (19.13±0.66) ram,and the ones to posterior ramus was (18.96± 0.64)mm. The angle of the mandible was (109.70±4.67)°. The rages of the remus for safe operation was (12.62±0.28)mm, and the safe rages about angle of the body and bottom of the mandible was (22.30±4.67)°. There were obvious differences from children to the aged in the mandible physiological and anatomic study. We can use Freeform system to simulate the operation on 3D model. Conclusion It is a new method to build 3D model and use Freefonn system to simulate operation and a new path to communion with patients for a good operation.

A prediction of bony interference between proximal and distal segment of the mandible with integrated 3d solid model and dental cast in orthognathic surgery

Three-dimensional solid model has not been widely used in surgical prediction of orthognathic surgery because freque from occlusal restorations or prosthesis limited the usefulness of simulated surgery involving occlusion. We prepared three-dimensional(3D) solid model from CT data and integrated the 3D solid model with dental cast using a face-bow transfer technique combined with skeletal reference measurement and confirmation with cephalometric radiographs. With this simple and easy method, it was possible to predict bony interference between the proximal and distal segment of the mandible so that we can prevent condylar displacement after sagittal split ramus osteotomy of the mandible with prominent asymmetry. The method error was within 2mm and it seemed to be useful in preoperative planning for maxillofacial surgery with maxillo-mandibular occlusal change