El efecto de la poda de Acropora palmata como estrategia para la obtención de tejido vivo en acciones de restauración arrecifal

Introducción: Los arrecifes de coral son ecosistemas altamente degradados, por lo que ha sido necesario implementar acciones de restauración activa para recuperar su estructura y funcionamiento. Se ha implementado la propagación clonal para obtener fragmentos pequeños (~ 10 cm) de las ramas distales de colonias donadoras de corales de la especie Acropora palmata, para posteriormente fijarlos en el sustrato arrecifal, simulando el efecto de dispersión que ocurre de manera natural en esta especie, a lo que en este trabajo se denomina ''dispersión asistida". Sin embargo, es necesario evaluar los efectos de esta técnica como son: la cantidad de fragmentos que se puede obtener de cada colonia, el periodo de recuperación de tejido de las colonias donadoras y los fragmentos sembrados. Objetivo: Evaluar el efecto de poda en las colonias donadoras estimando el porcentaje de tejido podado de colonias donadoras de A. palmata y su tasa de recuperación 30 meses después. Métodos: Se realizaron cuatro monitoreos: antes, inmediatamente después de la poda, un mes después de la siembra, y 30 meses después, en cuatro colonias de A. palmata localizadas en el Parque Nacional Costa Occidental de Isla Mujeres, Punta Cancún y Punta Nizuc en el Caribe mexicano. La modelación 3D basada en fotogrametría se realizó con el software Agisoft Metashape Pro, mientras que las métricas de área de superficie de tejido, extensión radial y apical se obtuvieron mediante el software CloudCompare. Resultados: Posterior a la colecta de fragmentos de las colonias, se observó que el material utilizado en la dispersión asistida representa menos del 12% del tejido vivo. Después de un mes, las colonias donadoras presentaban una recuperación del 5% con tejido nuevo recubriendo las áreas de corte. Las colonias donadoras perdieron, en promedio, 65% de tejido vivo tras el impacto de cuatro huracanes, y en un caso la colonia fue totalmente eliminada, pero con los fragmentos sembrados se pudo conservar el genotipo. Conclusiones: La dispersión asistida podría incrementar el tejido vivo de corales ramificados en intervalos de tiempo relativamente cortos, sin comprometer la integridad de la colonia donadora, si se poda menos del 12%.

Introduction: Coral reefs are highly degraded ecosystems, for which it has been necessary to implement active restoration actions to recover their structure and functioning. Asexual propagation has been implemented to obtain small fragments (~10 cm) from the distal branches of donor colonies of corals of the species Acropora palmata, to subsequently relocate them in the reef substrate, simulating the dispersion effect that occurs naturally in the species, which in this work is called assisted propagation. However, it is necessary to evaluate the effects of this technique, such as the number of fragments that can be obtained from each colony, the tissue recovery period of the donor colonies and fragments. Objective: To address the effect of pruning on donor colonies by estimating the percentage of live tissue removed from donor colonies of A. palmata and their recovery rate after 30-months. Methods: Four surveys were carried out: before, immediately after pruning, one month after outplanting, and 30 months after pruning on four colonies of A. palmata located in the Parque Nacional Costa Occidental de Isla Mujeres, Punta Cancún and Punta Nizuc in the Mexican Caribbean. Photogrammetry-based 3D modeling was performed using Agisoft Metashape Pro software, while tissue surface area, radial and apical growth were obtained using CloudCompare software. Results: After fragment collection, the material used in the assisted propagation represents less than 12% of the living tissue. After one month, the donor colonies showed a recovery of 5%, with new tissue covering the cut areas. The donor colonies lost on average 65 % of living tissue after four hurricanes, and in one case the colony was lost all together, but with the outplanted fragments the genotype could be preserved. Conclusions: Assisted propagation could increase living tissue of branching corals in relatively short intervals of time, without serious damage to the donor colony if less than 12 % is removed.

In silico structural modeling and quality assessment of Plasmodium knowlesi apical membrane antigen 1 using comparative protein models

@#Plasmodium knowlesi is the most common zoonotic parasite associated with human malaria infection in Malaysia. Apical membrane antigen 1 (AMA1) protein in the parasite plays a critical role in parasite invasion into host cells. To date, there is no complete three-dimensional ectodomain structure of P. knowlesi AMA1 (PkAMA1) protein. The knowledge of a protein structure is important to understand the protein molecular functions. Three in silico servers with respective structure prediction methods were used in this study, i.e., SWISS-MODEL for homology modeling and Phyre2 for protein threading, which are template-based modeling, while I-TASSER for template-free ab initio modeling. Two query sequences were used in the study, i.e., native ectodomain of PkAMA1 strain H protein designated as PkAMA1-H and a modified PkAMA1 (mPkAMA1) protein sequence in adaptation for Pichia pastoris expression. The quality of each model was assessed by ProSA-web, QMEAN and SAVES v6.0 (ERRAT, Verify3D and Ramachandran plot) servers. Generated models were then superimposed with two models of Plasmodium AMA1 deposited in Protein Data Bank (PDB), i.e., PkAMA1 (4UV6.B) and Plasmodium vivax AMA1 (PvAMA1, 1W81) protein structures for similarity assessment, quantified by root-meansquare deviation (RMSD) value. SWISS-MODEL, Phyre2 and I-TASSER server generated two, one and five models, respectively. All models are of good quality according to ProSA-web assessment. Based on the average values of model quality assessment and superimposition, the models that recorded highest values for most parameters were selected as best predicted models, i.e., model 2 for both PkAMA1-H and mPkAMA1 from SWISS-MODEL as well as model 1 of PkAMA1-H and model 3 of mPkAMA1 from I-TASSER. Template-based method is useful if known template is available, but template-free method is more suitable if there is no known available template. Generated models can be used as guidance in further protein study that requires protein structural data, i.e., protein-protein interaction study.

3D printing of canine hip dysplasia: anatomic models and radiographs / Impressão 3D da displasia coxofemoral canina: modelos anatômicos e radiografias

Canine Hip Dysplasia (CHD) is a highly prevalent articular pathological condition. In this sense, radiography becomes an important diagnostic method to determine the presence and severity of the disease. The objective was to create 3D models and their respective radiographs representing the CHD (3D AMCHD). The research was carried out in the Laboratory of 3D Educational Technologies of UFAC, under no. 23107.007273/2017-49 (CEUA/UFAC). A canine skeleton (hip bone, femurs and patellae) was used without anatomical deformities compatible with DCF (pelvis, femurs and patella), which were scanned in order to obtain the files of the base model. In these files the deformations representing the different degrees of CHD were performed. Subsequently, the 3D AMCHD files were printed, mounted and X-rayed. The 3D AMCHD represented the bone deformations of the different degrees of CHD. In the radiographs of the 3D AMCHD it was possible to observe and determine each of the bones that constituted the hip joints. This allowed to reproduce the correct positioning to represent the CHD diagnosis and establish the precise points to determine the Norberg angle. In this way, it was evidenced that the 3D AMCHD can be a possible tool to be used in the Teaching of Veterinary Medicine.(AU)

A displasia coxofemoral canina (DCF) é uma condição patológica articular de grande prevalência. Nesse sentido, a radiografia torna-se um método de diagnóstico importante para determinar a presença e a gravidade da doença. O objetivo do presente trabalho foi criar modelos 3D e suas respectivas radiografias representando a DCF (MADCF 3D). A pesquisa foi realizada no Laboratório de Tecnologias Educacionais 3D da UFAC, sob o nº. 23107.007273/2017-49 (Ceua/Ufac). Foram utilizados esqueletos caninos (pelve, fêmures e patelas) sem deformidades anatômicas compatíveis com a DCF, os quais foram digitalizados a fim de se obterem os arquivos do modelo base. Nesses arquivos foram realizadas as deformações que representavam os diferentes graus da DCF. Posteriormente, os arquivos dos MADCF 3D foram impressos, montados e radiografados. Os MADCF 3D representaram as deformações ósseas dos diferentes graus da DCF. Nas radiografias dos MADCF 3D, foi possível observar e determinar cada um dos ossos que constituíam as articulações coxofemorais. Isso permitiu reproduzir o posicionamento correto para representação do diagnóstico DCF e estabelecer os pontos precisos para determinar o ângulo de Norberg. Dessa forma, evidenciou-se que os MADCF 3D podem ser uma possível ferramenta a ser empregada no ensino de medicina veterinária.(AU)

Advanced Medical Use of Three-Dimensional Imaging in Congenital Heart Disease: Augmented Reality, Mixed Reality, Virtual Reality, and Three-Dimensional Printing

Feasibility of low-dose radiation CT scanning for liver 3D modeling printing / 医学研究生学报

Objective In the wide clinical practice of liver 3D printing, its related high-dose CT radiation has been somehow neglected and resulted in unnecessary radiation injury to the patients. This study was to explore the feasibility of liver 3D modeling printing with the low-dose radiation CT scanning technique.　Methods　This retrospective study included 40 patients undergoing liver 3D modeling printing from January 2016 to June 2018, who were equally randomized into a low-dose radiation group (100 kVp, by automated tube current modulation [ATCM] and adaptive statistical iterative reconstruction [ASIR]) and a normal-dose radiation group (120 kVp, 250 mA by filter back projection [FBP]), both with contrast agent Iohexol at 300 mgI/m1. We obtained the values of three-phase enhanced CT scanning of the abdominal aorta, portal vein and liver parenchyma, background noise (BN), volume CT dose index (CTDI), dose length product (DLP), contrast noise ratio (CNR) and effective radiation dose (ED). We input the CT DICOM data into the 3D printer for liver modeling printing and subjectively assessed the results. Results There were statistically significant differences between the low-dose and normal-dose radiation groups in the CTDI, DLP and ED (P 0.05). The ED was decreased about 35.8% in the low-dose group as compared with that in the normal-dose group ([2.58 ± 0.79] vs [4.02 ± 0.26] mSv, P 0.05). Conclusion Low-dose radiation CT scanning technology can meet the clinical requirement of liver 3D modeling printing and significantly reduce the patient’s exposure to CT radiation.

Approaches to the preparation of the oral cavity for prosthetics using computer simulation: An analysis of domestic and foreign experience / 国际药学研究杂志

The article analyzes domestic and foreign experience in planning the preparation of oral cavity for prosthetics. Recently, thanks to the development of computer technology, the possibility of virtual 3D-modeling of the prosthesis design and its further prototyping has appeared [1; 2; 5]. Digital treatment planning, based on three-dimensional imaging procedures, allows you to plan therapy with absolute precision and makes the outcome of treatment exactly predictable. Analysis of domestic experience shows that one of the most common in the practice of orthopedic dentistry is the program Blue Sky Plan. Patterns made in the program are easily exported to STL files and do not require additional processing. The program contains a wide range of implant systems. In foreign practice, guided surgery from DENTSPLY Implants is very popular, which offers a comprehensive solution for digital treatment planning and placement of implants based on SIMPLANT software templates.

Preliminary use of HoloLens glasses in surgery of liver cancer / 中南大学学报(医学版)

Objective:To establish the preoperative three dimensional (3D) model of liver cancer,and to precisely match the preoperative planning with the target organs during the operation.Methods:The 3D model reconstruction based on magnetic resonance data,which was combined with virtual reality technology via HoloLens glasses,was applied in the operation of liver cancer to achieve preoperative 3D modeling and surgical planning,and to directly match it with the operative target organs during operation.Results:The 3D model reconstruction of liver cancer based on magnetic resonance data was completed.The exact match with the target organ was performed during the operation via HoloLens glasses leaded by the 3D model.Conclusion:Magnetic resonance data can be used for the 3D model reconstruction to improve preoperative assessment and accurate match during the operation.

Structural and mechanical characterization of custom design cranial implant created using additive manufacturing

Background: Reconstruction of customized cranial implants with a mesh structure using computer-assisted design and additive manufacturing improves the implant design, surgical planning, defect evaluation, implant-tissue interaction and surgeon's accuracy. The objective of this study is to design, develop and fabricate cranial implant with mechanical properties closer to that of bone and drastically decreases the implant failure and to improve the esthetic outcome in cranial surgery with precision fitting for a better quality of life. A customized cranial mesh implant is designed digitally, based on the Digital Imaging and Communication in Medicine files and fabricated using state of the Art-Electron Beam Melting an Additive Manufacturing technology. The EBM produced titanium implant was evaluated based on their mechanical strength and structural characterization. Results: The result shows, the produced mesh implants have a high permeability of bone ingrowth with its reduced weight and modulus of elasticity closer to that the natural bone thus reducing the stress shielding effect. Scanning electron microscope and micro-computed tomography (CT) scanning confirms, that the produced cranial implant has a highly regular pattern of the porous structure with interconnected channels without any internal defect and voids. Conclusions: The study reveals that the use of mesh implants in cranial reconstruction satisfies the need of lighter implants with an adequate mechanical strength, thus restoring better functionality and esthetic outcomes for the patients.

Structure of the 40S ribosomal subunit ofby homology andmodeling

Generation of three dimensional structures of macromolecules usingstructural modeling technologies such as homology andmodeling has improved dramatically and increased the speed by which tertiary structures of organisms can be generated. This is especially the case if a homologous crystal structure is already available. High-resolution structures can be rapidly created using only their sequence information as input, a process that has the potential to increase the speed of scientific discovery. In this study, homology modeling and structure prediction tools such as RNA123 and SWISS-MODEL were used to generate the 40S ribosomal subunit fromThis structure was modeled using the published crystal structure from, a homologous eukaryote. In the absence of the40S ribosomal crystal structure, the model accurately depicts a global topology, secondary and tertiary connections, and gives an overall root mean square deviation (RMSD) value of 3.9 Å relative to the template׳s crystal structure. Deviations are somewhat larger in areas with no homology between the templates. These results demonstrate that this approach has the power to identify motifs of interest in RNA and identify potential drug targets for macromolecules whose crystal structures are unknown. The results also show the utility of RNA homology modeling software for structure determination and lay the groundwork for applying this approach to larger and more complex eukaryotic ribosomes and other RNA-protein complexes. Structures generated from this study can be used inscreening experiments and lead to the determination of structures for targets/hit complexes.

Innovative practice of project-based learning and 3 D printing in Computer-aided medicine / 中华医学图书情报杂志

After the application of project-based learning (PBL) and 3D printing in classroom and teaching, the integrating methods and principles of PBL and 3D printing and recent teaching resources were summarized, PBL-based 3D modeling combined with recent innovative practice of 3D printing teaching model, with the course of Computer-aided medicine as an example, showed that the new teaching mode can effectively stimulate the interests of students, and cultivate their innovative thinking.

Automated three-dimensional measurement on anatomic parameters of proximal femur / 医用生物力学

ObjectiveTo automatically measure anatomic parameters of proximal femur by establishing three-dimensional (3D) coordinate system of the femur based on bony landmarks, so as to assist pre-operative planning and design of customized femoral stem. MethodsThe software named "Femeter" was independently developed for anatomic measurement of the femur, which allowed importing the femur models with STL format and manually locating the targeted anatomic landmarks. The 3D modeling of femoral medullary canal was rapidly created by semi-spherical iterative searching algorithm, and 16 key anatomic parameters of proximal femur, including femoral head radius, neck-shaft angle, anterversion were automatically calculated by least-squares fitting algorithm. ResultsBy experimenting on 30 femur STL models, the average execution time of single measurement was (0.95±0.16) seconds, and the intra-class correlation coefficient of 9 anatomic parameters was between 0.907 and 0.999, which showed high intra-rater and inter-rater reliability. ConclusionsThe automatic modeling and execution time of measuring algorithm by Femeter are fast, with satisfactory measurement repeatability and easy interaction, which is easily applicable to clinical practice. The 3D anatomic measurement of proximal femur can provide solid data for pre-operative planning of total hip arthroplasty, selection of commercialized femoral stem and design of customized femoral stem.

Research on VTK and Geomagic-based 3D craniofacial composite modeling / 中国医学装备

Objective:To construct 3D craniofacial composite model for clinical diagnosis, simulation and teaching.Methods: Collect head CT image data, and apply MC isosurface rendering method of VTK to reconstruction the 3D models of bones and the dough, then import 3D model into 3D modeling software Geomagic to repair the holes and defects, and finally complete 3D model reconstruction of craniofacial composite model by the comprehensive function of composite.Results: The experiment shows that VTK can reconstruct the 3D craniofacial model quickly, automatically, Geomagic can repair the automatic reconstruction model of defects and holes, the generated composite 3D model can fully and effectively display the three-dimensional composite structures of facial and skull. Conclusion: Using VTK and Geomagic can achieve efficient 3D modeling, and the composite model provided an effective visual reference for the face of the repair, plastic surgery and medical education.

A Tool Box to Evaluate the Phased Array Coil Performance Using Retrospective 3D Coil Modeling

PURPOSE: To efficiently evaluate phased array coil performance using a software tool box with which we can make visual comparison of the sensitivity of every coil element between the real experiment and EM simulation. MATERIALS AND METHODS: We have developed a C++- and MATLAB-based software tool called Phased Array Coil Evaluator (PACE). PACE has the following functions: Building 3D models of the coil elements, importing the FDTD simulation results, and visualizing the coil sensitivity of each coil element on the ordinary Cartesian coordinate and the relative coil position coordinate. To build a 3D model of the phased array coil, we used an electromagnetic 3D tracker in a stylus form. After making the 3D model, we imported the 3D model into the FDTD electromagnetic field simulation tool. RESULTS: An accurate comparison between the coil sensitivity simulation and real experiment on the tool box platform has been made through fine matching of the simulation and real experiment with aids of the 3D tracker. In the simulation and experiment, we used a 36-channel helmet-style phased array coil. At the 3D MRI data acquisition using the spoiled gradient echo sequence, we used the uniform cylindrical phantom that had the same geometry as the one in the FDTD simulation. In the tool box, we can conveniently choose the coil element of interest and we can compare the coil sensitivities element-by-element of the phased array coil. CONCLUSION: We expect the tool box can be greatly used for developing phased array coils of new geometry or for periodic maintenance of phased array coils in a more accurate and consistent manner.

Development of Multi Graphic Image Authoring tool for Medical Visual Information / 대한의료정보학회지

Recently, the trends of medical information technologies are capturing digital image from medical analog information, medical image aquisition, transmission, storage and query as well as integration with hospital information system. Analog medical visual information from ultrasonic, MRI can be changed into digital medical information, and to connect with medical video information system which need frame editing, 3D modeling and rendering. The purpose of this study is to design multi graphic image authoring tool and development of digital video editing functionalities, which can be used usefully for medical visual editing tool as well as vector image production system. The implementation methodology is based on Object-Oriented Modeling with primitive, media and composition object with reusability and inheritance characteristics, which can be useful for interleaving various type of media into video stream. The system assesment is based on international recommendation ISO 15504 81W process capability determination. We select 6 processes from Engineering process of system requirement analysis and design category, and determine capability for selected SIW process for system assesment.

Establishment of three-dimensional finite element model of teeth by CAE software / 实用口腔医学杂志

objective: To generate 3 D model of teeth for finite element method(FEM) analysis by computer. Methods: On the basis of 3 D model created by 3D Max, the 3 D FEM model of teeth was generated by using of CAE software. Boundary condition was set in the part of teeth root with elastic constraint. The elastic modulus was chosen as the modulus of periodontium. Results: Generated right inciser model comprised of 25 386 units and 5 111 nodal points. Conclusion: 3 D FEM model of tooth can be generated by CAE software.