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The burden of osteoarthritis (OA) is around 300 million people affected worldwide, with the hip representing a commonly affected joint. Total hip arthroplasty (THA) has been used with notable success as a definitive treatment to improve pain and function in hip OA patients. The recent advent of new technologies, such as 3D printing, has pushed the application of these new concepts toward applications for the well-known THA. Currently, the evidence on the use of 3D printing to aid complex primary THA cases is still scarce. Methods: An extensive literature review was conducted to retrieve all articles centered on the use of 3D printing in the setting of primary THA. Results: A total of seven studies were included in the present systematic review. Four studies investigated the use of 3D-printed surgical guides to be used during surgery. The remaining three studies investigated the benefit of the use of 3D-printed templates of the pelvis to simulate the surgery. Conclusions: The use of 3D printing could be a promising aid to solve difficult primary total hip arthroplasty cases. However, the general enthusiasm in the field is not supported by high-quality studies, hence preventing us from currently recommending its application in everyday practice. [ABSTRACT FROM AUTHOR]

Abstract: Nylon models of earliest Cretaceous Pantanellium were produced from a real fossil specimen by applying X-ray micro-CT and layered manufacturing technology. These models enable us to elucidate the exact number of polygonal pore frames and their configuration on the cortical shell, which is difficult to recognize from scanning electron microscope or light microscope images. The specimen has a total number of 27 polygonal (12 pentagonal and 15 hexagonal) pore frames. The pore frame number and the configuration are important criteria in the taxonomy of the Family Pantanelliidae. Planar graphs showing the distribution of polygonal pore frames on the cortical shell are depicted. They are expected to be a standard method for presenting and examining geometrical characters of pantanellid cortical shells. The new technology of X-ray micro-CT can shed light on detailed morphological examinations of not only radiolarians but also any other microfossils. [Copyright &y& Elsevier]

Museums are embracing new technologies and one of these is the use of 3D printing. 3D printing allows for creating physical replicas of items which may, due to great value or significance, not be handled by the public, or which are too small or fragile to be handled or even seen with the naked eye. One such application of new technologies has been welcomed by the National Museum in Bloemfontein, Free State, South Africa. Here, blown-up (enlarged) Museum specimens were 3D printed for various interactive exhibits that are aimed at increasing the accessibility of their permanent displays for visually impaired visitors who rely greatly on touch as a source of observation. A selection of scorpions, pseudoscorpions, mites and archetypal bird skulls were scanned, processed and 3D printed to produce enlarged, highly functional nylon models. This data paper provides the raw micro Computed Tomography (micro-CT) scan data and print ready STL files processed from this data. The STL files may be used in their current format and details of the printing are provided.

The advent of three-dimensional (3D) printing in the 1980s ushered in a new era of manufacturing. Original 3D printers were large, expensive and difficult to operate, but recent advances in 3D printer technologies have drastically increased the accessibility of these machines such that individual surgical departments can now afford their own 3D printers. As adoption of 3D printing technology has increased within the medical industry so too has the number of 3D printable materials. Selection of the appropriate printer and material for a given application can be a daunting task for any clinician. This review seeks to describe the benefits and drawbacks of different 3D printing technologies and the materials used therein. Commercially available printers using fused deposition modelling or fused filament fabrication technology and relatively inexpensive thermoplastic materials have enabled rapid manufacture of anatomic models and intraoperative tools as well as implant prototyping. Titanium alloys remain the gold-standard material for various implants used in the fixation of craniofacial or extremity fractures, but polymers and ceramics are showing increasing promise for these types of applications. An understanding of these materials and their compatibility with various 3D printers is essential for application of this technology in a healthcare setting. [ABSTRACT FROM AUTHOR]

Introduction: In the equine racehorse industry, reduced athletic performance due to joint injury and lameness has been extensively reviewed. Intra-articular injections of glucocorticoids are routinely used to relieve pain and inflammation associated with osteoarthritis. Intra-articular injections of pharmaceutical agents require practice for precise needle placement and to minimize complications. Training on simulators or models is a viable alternative for developing these technical skills. The purpose of this study was to compare the qualitative ultrasonographic characteristics of three-dimensional (3D) printed models of equine cervical articular process joints to that of a dissected equine cervical spine (gold standard). Methods: A randomized complete block design study was conducted in which a total of thirteen cervical articular process joint models were printed using several materials, printers, and printing technologies. Ultrasound video clips with the models immersed in water were recorded. Two board certified veterinary radiologists and three veterinary radiology residents reviewed the videos and responded to a survey assessing and comparing the ultrasonographic characteristics of the 3D printed models to those of the gold standard. Results: Six 3D printed models had ultrasonographic characteristics similar to the gold standard. These six models were (material, printer, printing technology): nylon PA 12, EOS Formiga P100, selective laser sintering (P = 0.99); Onyx nylon with chopped carbon fiber, Markforged Onyx Two, fused deposition modeling (P = 0.48); polycarbonate, Ultimaker 3, fused deposition modeling (P = 0.28); gypsum, ProJet CJP 660 Pro, ColorJet Printing (P = 0.28); polylactic acid, Prusa I3, fused deposition modeling (P = 0.23); and high temperature V1 resin, Form 2, stereolithography (P = 0.22). Conclusion: When assessed in water, it is possible to replicate the qualitative ultrasonographic characteristics of bone using three dimensional printed models made by combining different materials, printing technologies, and printers. However, not all models share similar qualitative ultrasonographic characteristics with bone. We suggest that the aforementioned six models be used as proxy for simulating bones or joints for use with ultrasound. In order to replicate the resistance and acoustic window provided by soft tissues, further work testing the ability of these models to withstand embedding in material such as ballistic gelatin is required. [ABSTRACT FROM AUTHOR]

View large Download slide View large Download slide OBJECTIVES The aim of this study was to develop a process for modelling and 3-dimensional (3D) printing of different mitral valve diseases for procedural planning and simulation, based on 3D transoesophageal echocardiography (TOE). METHODS 3D TOE was used to reconstruct a fully dynamic 3D view of the diseased valve. Reconstructions were cropped at the level of the valve and captured in mid-systole to assess the coaptation defect. Reconstructions were then exported as a surface mesh. To ensure a watertight and noise-reduced model, the mesh was processed using computer-modelling programmes, whereupon the valve was printed in 3D. For simulation purposes, deformable models were created based on negative mould fabrication and cast in tissue-mimicking silicone. Model validation was performed by intraoperative assessment of the valvular disease and repair strategy. RESULTS The mitral valves of 10 prospective patients with different diseases were modelled. In 6 patients, a 3D printed rigid plastic mitral valve was created for procedural planning, and in 4 patients, a silicone-cast replica was created for procedural simulation. All models were created to scale, implying conservation of in vivo dimensions. Models were validated by in vivo comparison. Total workaround time ranged from 3 to 4 h and 2 to 3 days for rigid plastic and silicone models, respectively. Costs were €15 to €40 and €300, respectively. CONCLUSIONS We demonstrated the feasibility of creating rigid plastic and tissue-mimicking silicone mitral valve replications. These models could be used in the future to enhance surgical anatomical interpretation, to facilitate planning and simulation of complex surgeries and for training purposes. [ABSTRACT FROM AUTHOR]

Internal weapons bays are becoming increasingly common on aircraft for reasons of stealth and aerodynamic performance, and will be even more prevalent on coming generations of unmanned combat aerial vehicles (UCAVs). Wind tunnel testing of store releases to assess forces and moments for safety and clearance must be conducted with a store mounted to an angled strut rather than a conventional rear sting, to allow the full range of motion as the store “drops” from inside the aircraft. Interference from this strut can disrupt the flowfields and thus the reliability of moments obtained, and therefore an investigation was conducted to quantify the potential extent of discrepancies; original small-scale transonic wind tunnel testing was undertaken in a limited program which was supported by extensive numerical work. It was concluded that the precise geometry of the strut/store interface was of critical importance, with a typical design producing non-linear interference at high angles of attack. A simple improved design is proposed – making use of a blended interface and a more appropriate supercritical aerofoil strut cross section – yielding marked improvements in force and moment predictions. [ABSTRACT FROM AUTHOR]

Following the invention of the first computed tomography (CT) scanner in the early 1970s, many innovations in three-dimensional (3D) diagnostic imaging technology have occurred, leading to a wide range of applications in craniofacial clinical practice and research. Three-dimensional image analysis provides superior and more detailed information compared with conventional plain two-dimensional (2D) radiography, with the added benefit of 3D printing for preoperative treatment planning and regenerative therapy. Current state-of-the-art multidetector CT (MDCT), also known as medical CT, has an important role in the diagnosis and management of craniofacial injuries and pathology. Three-dimensional cone beam CT (CBCT), pioneered in the 1990s, is gaining increasing popularity in dental and craniofacial clinical practice because of its faster image acquisition at a lower radiation dose, but sound guidelines are needed to ensure its optimal clinical use. Recent innovations in micro-computed tomography (micro-CT) have revolutionized craniofacial biology research by enabling higher resolution scanning of teeth beyond the capabilities of MDCT and CBCT, presenting new prospects for translational clinical research. Even after four decades of refinement, CT technology continues to advance and broaden the horizons of craniofacial clinical practice and phenomics research. [ABSTRACT FROM AUTHOR]

The field of structural biology currently relies on computer-generated graphical representations of three-dimensional (3D) structures to conceptualize biomolecules. As the size and complexity of the molecular structure increases, model generation and peer discussions become more difficult. It is even more problematic when discussing protein-protein interactions wherein large surface area contact is considered. This report demonstrates the viability of a new handleable protein molecular model with a soft and transparent silicone body similar to the molecule's surface. A full-color printed main chain structure embedded in the silicone body enables users to simultaneously feel the molecular surface, view through the main chain structure, and manually simulate molecular docking. The interactive, hands-on experience deepens the user's intuitive understanding of the complicated 3D protein structure and elucidates ligand binding and protein-protein interactions. This model would be an effective discussion tool for the classroom or laboratory that stimulates inspired learning in this study field. [ABSTRACT FROM AUTHOR]

The technology now exists to construct physical models of proteins based on atomic coordinates of solved structures. We review here our recent experiences in using physical models to teach concepts of protein structure and function at both the high school and the undergraduate levels. At the high school level, physical models are used in a professional development program targeted to biology and chemistry teachers. This program has recently been expanded to include two student enrichment programs in which high school students participate in physical protein modeling activities. At the undergraduate level, we are currently exploring the usefulness of physical models in communicating concepts of protein structure and function that have been traditionally difficult to teach. We discuss our recent experience with two such examples: the close-packed nature of an enzyme active site and the pH-induced conformational change of the influenza hemagglutinin protein during virus infection. [ABSTRACT FROM AUTHOR]

Hypersonic wind-tunnel tests of thirteen 7 3/4-in.-diam Plexiglas and nylon hemispheres were designed and conducted at the Polytechnic Institute of Brooklyn utilizing a shrouded-model technique to simulate Mach 15 to 20 flight. The models were instrumented with thermocouples ans strain gages from which continous time histories of temperature and strain were recorded. In addition, ablation measurements were made after themodels were tested. The experimental results are compared with theoretical calculations of strain, temperature and ablation. Using a point-symmetric heat-balance method to determine the ablation and temperature histories, a thermal stress analysis is conducted in which variations in the modulus of elasticity with temperature are approximated by a concentric-layer technique. The effects of axisymmetric pressure distributions, as well as the effects of the boundary condition imposed by the model support, are considered in an axisymmetric alyer analysis. A comparison between theroy and experiment indicates good qualitative results and good-to-poor quantitative results. The details of the analyses, and the comparison between the theoretical predictions and experiment are discussed. [ABSTRACT FROM AUTHOR]

Author(s): Jesus Mavarez (corresponding author) [1, 4]; Camilo A. Salazar [2, 4]; Eldredge Bermingham [1]; Christian Salcedo [2]; Chris D. Jiggins [3]; Mauricio Linares (corresponding author) [2] Speciation is generally [...]

BOTANY SECTION DWAYNE ESTES, CHAIR A SYNOPSIS OF THE WOODY FLORA OF TENNESSEE. Edward W. Chester and B. Eugene Wofford, Austin Peay State University, Clarksville, Tennessee and The University of [...]