articles+ search results

Open source software, Public software -- Analysis, and Rapid prototyping -- Analysis

Keywords: Dynamic optimization; Dynamic simulation; Pyomo; Process control; Williams-Otto process Abstract With ongoing digitalization, fast simulation of process dynamics offers new opportunities for model-based control schemes. This is eased by the availability of high-level, open-access, easy-to-use software able to simulate and optimize chemical processes, making rapid prototyping possible also for the chemical engineer. In this study, the capabilities of the Python-based open-source software package Pyomo towards industrial application is illustrated in modeling and comparing different control schemes for a simple Williams-Otto process. It is shown how to simulate the process dynamics and how to compute optimal control trajectories for minimizing waste and maximizing yield. Two approaches to setpoint tracking are compared: one based on proportional-integral feedback control and one based on optimal open-loop control. Byline: Julia Riese, Jochen Schmid, Katrin Teichert, Moncef Chioua, Thorsten Schindler, Michael Bortz

Rapid prototyping and Autografts

Keywords: digital dentistry; endodontics; laboratory technology; oral surgery; pain Abstract Objective To describe a method to fabricate donor tooth replica to assist surgeons in preparation of recipient socket during tooth autotransplantation. Materials and Methods A total of 28 compromised molars in 27 patients were transplanted with third molars using computer-aided rapid prototyping (CARP) technique. Surgery time and extra-alveolar time were documented. Postoperatively, the distance between cervix of transplanted tooth and the alveolar wall was measured. The degree of postoperative pain experienced was assessed with visual analog scale at day 1, 3, and 7. Results From 28 clinical cases, the average extra-alveolar time and surgery time were 2.5 minutes ([+ or -]1.3) and 44minutes ([+ or -]6.8), respectively. Postoperatively, the average distance between cervix of transplanted tooth and the alveolar wall was 0.87mm ([+ or -]0.15) at the mesial-cervix, 0.95mm ([+ or -]0.17) at the distal-cervix, 0.88mm ([+ or -]0.18) at the buccal-cervix, and 0.95mm ([+ or -]0.13) at the lingual-cervix. The value of visual analog scale score significantly decreased from day 1 to day 3. Conclusions CARP is a reliable technique for fabrication of tooth like surgical replicas in conventional autotransplantation. Clinical Significance CARP technique minimized extra-oral time, reduced iatrogenic damage, and consequently increased the survival rate of tooth autotransplantation. Byline: Jia-jia Xia, Zi-yu Ge, Xiao-hui Fu, Yan-zhen Zhang

Computer-aided design -- Analysis, Implants, Artificial -- Analysis, Prosthesis -- Analysis, and Rapid prototyping -- Analysis

Abstract Statement of problem Although closed hollow obturator prostheses provide the benefit of minimized weight, they also pose challenges. They are complex to fabricate, and contaminated water can easily enter the hollow section through the joined part, making them unsanitary and leading to malodor and increased weight. Purpose The purpose of this in vitro study was to investigate the hermeticity and durability of a hollow obturator model fabricated by using computer-aided design (CAD) and rapid prototyping (RP) techniques and to evaluate the possibility of its clinical use. Material and methods Leak testing was used to evaluate the hermeticity and durability of hollow spherical obturator specimens with an outer diameter of 30 mm and 2 different wall thicknesses (1.5 and 2.0 mm). Six specimens were fabricated for each of the wall thicknesses by using CAD and RP techniques. The accumulation of fluids in the hollow obturator specimens was evaluated every day by using megascopic observation with photoirradiation from the base of the specimens. The amount of water absorption and the rate of increase in the weight of the 2 specimens were calculated and compared. Statistical analysis was performed by using the Mann-Whitney U test ([alpha]=.05). Results The application of CAD and RP techniques made it possible to fabricate a hollow obturator model specimen with completely unified parts. The 1.5-mm specimen showed an absorption rate (2.61%) that significantly exceeded that of the 2.0-mm specimen (2.53%) on day 130 (P=.006). By the end of the observation period, the 1.5-mm specimen exhibited large amounts of water absorption and destruction. The 1.5-mm-thick wall had reduced hermeticity than the 2.0-mm-thick wall. Conclusions A fully unified hollow obturator model with 2.0-mm-thick walls was fabricated by using CAD and RP techniques. The absence of any joints prevented fluid accumulation, making this method suitable for the fabrication of hollow prostheses. Author Affiliation: (a) Associate Professor, Maxillofacial Prosthetics Clinic, Tohoku University Hospital, Sendai, Japan (b) Assistant Professor, Maxillofacial Prosthetics Clinic, Tohoku University Hospital, Sendai, Japan (c) Assistant Professor, Maxillofacial Prosthetics Clinic, Tohoku University Hospital, Sendai, Japan (d) Assistant Professor, Maxillofacial Prosthetics Clinic, Tohoku University Hospital, Sendai, Japan (e) Professor, Division of Advanced Prosthodontics, Graduate School of Dentistry, Tohoku University, Sendai, Japan * Corresponding author: Dr Shigeto Koyama, Tohoku University Hospital, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, JAPAN Byline: Shigeto Koyama, DDS, PhD [koyama@dent.tohoku.ac.jp] (a,*), Naoko Sato, DDS, PhD (b), Takehiko Mito, DDS, PhD (c), Kuniyuki Izumita, DDS, PhD (d), Keiichi Sasaki, DDS, PhD (e)

Rapid prototyping, Proteins, Genetic research, Mail-order industry, Fluorescence, Protein biosynthesis, Genes, Escherichia coli, and DNA synthesis

Byline: Jared Lynn Dopp, Samuel Michael Rothstein, Thomas Joseph Mansell,Nigel Forest Reuel Keywords: cell-free protein synthesis; linear template; rolling circle amplification Abstract In this study, we present a minimal template design and accompanying methods to produce assayable quantities of custom sequence proteins within 24hr from receipt of inexpensive gene fragments from a DNA synthesis vendor. This is done without the conventional steps of plasmid cloning or cell-based amplification and expression. Instead the linear template is PCR amplified, circularized, and isothermally amplified using a rolling circle polymerase. The resulting template can be used directly with cost-optimized, scalably-manufactured Escherichia coli extract and minimal supplement reagents to perform cell-free protein synthesis (CFPS) of the template protein. We demonstrate the utility of this template design and 24hr process with seven fluorescent proteins (sfGFP, mVenus, mCherry, and four GFP variants), three enzymes (chloramphenicol acetyltransferase, a chitinase catalytic domain, and native subtilisin), a capture protein (anti-GFP nanobody), and 2 antimicrobial peptides (BP100 and CA(1-7)M(2-9)). We detected each of these directly from the CFPS reaction using colorimetric, fluorogenic, and growth assays. Of especial note, the GFP variant sequences were found from genomic screening data and had not been expressed or characterized before, thus demonstrating the utility of this approach for phenotype characterization of sequenced libraries. We also demonstrate that the rolling circle amplified version of the linear template exhibits expression similar to that of a complete plasmid when expressing sfGFP in the CFPS reaction. We evaluate the cost of this approach to be $61/mg sfGFP for a 4hr reaction. We also detail limitations of this approach and strategies to overcome these, namely proteins with posttranslational modifications. CAPTION(S): Supplementary information

3D printing -- Methods

1. Introduction Microfabrication techniques have revolutionized the way biologists and medical scientists conduct studies in the last few decades [1]. The well-developed semiconductor workflow enables not only the creation of [...]
C[O.sub.2] laser manufacturing has served as an enabling and reliable tool for rapid and cost-effective microfabrication over the past few decades. While a wide range of industrial and biological applications have been studied, the choice of materials fabricated across various laser parameters and systems is often confounded by their complex combinations. We herein presented a unified procedure performed using percussion C[O.sub.2] laser drilling with a range of laser parameters, substrate materials and various generated microstructures, enabling a variety of downstream tissue/cellular-based applications. Emphasis is placed on delineating the laser drilling effect on different biocompatible materials and proof-of-concept utilities. First, a polydimethylsiloxane (PDMS) microneedle (MN) array mold is fabricated to generate dissolvable polyvinylpyrrolidone/polyvinyl alcohol (PVP/PVA) MNs for transdermal drug delivery. Second, polystyrene (PS) microwells are optimized in a compact array for the formation of size-controlled multicellular tumor spheroids (MCTSs). Third, coverglass is perforated to form a microaperture that can be used to trap/position cells/spheroids. Fourth, the creation of through-holes in PS is validated as an accessible method to create channels that facilitate medium exchange in hanging drop arrays and as a conducive tool for the growth and drug screenings of MCTSs. Keywords: C[O.sub.2] laser; rapid prototyping; microneedle; multicellular tumor spheroids; microwells; hanging drops

Magnetization and Rapid prototyping

Byline: Jon-Fredrik Nielsen, Douglas C. Noll Keywords: pulse sequence programming; pulse sequence prototyping; platform-independent; open source; open MRI Purpose To introduce a framework for rapid prototyping of MR pulse sequences. Methods We propose a simple file format, called 'TOPPE', for specifying all details of an MR imaging experiment, such as gradient and radiofrequency waveforms and the complete scan loop. In addition, we provide a TOPPE file 'interpreter' for GE scanners, which is a binary executable that loads TOPPE files and executes the sequence on the scanner. We also provide MATLAB scripts for reading and writing TOPPE files and previewing the sequence prior to hardware execution. With this setup, the task of the pulse sequence programmer is reduced to creating TOPPE files, eliminating the need for hardware-specific programming. No sequence-specific compilation is necessary; the interpreter only needs to be compiled once (for every scanner software upgrade). We demonstrate TOPPE in three different applications: k-space mapping, non-Cartesian PRESTO whole-brain dynamic imaging, and myelin mapping in the brain using inhomogeneous magnetization transfer. Results We successfully implemented and executed the three example sequences. By simply changing the various TOPPE sequence files, a single binary executable (interpreter) was used to execute several different sequences. Conclusion The TOPPE file format is a complete specification of an MR imaging experiment, based on arbitrary sequences of a (typically small) number of unique modules. Along with the GE interpreter, TOPPE comprises a modular and flexible platform for rapid prototyping of new pulse sequences. Magn Reson Med 79:3128-3134, 2018. [c] 2017 International Society for Magnetic Resonance in Medicine. Supporting information: Additional Supporting Information may be found in the online version of this article Additional Supporting Information may be found in the online version of this article. CAPTION(S): Fig. S1. Pulse sequence diagram for the k-space trajectory measurements shown in Figure 3. Fig. S2. Example of a TOPPE sequence with multiple (64) different gy and gz waveforms associated with one .mod file. Only two of the waveforms are shown. All 64 waveforms are loaded into scanner memory during sequence prescription. During sequence execution, the particular waveform to be played out is selected on-the-fly according to the corresponding entry in scanloop.txt. In this example, each waveform is of duration 40 ms. We successfully ran this sequence and switched the waveforms during sequence execution (not shown), according to the instructions in scanloop.txt. With the possibility of up to 20 different .mod files, each containing multiple waveforms, we believe TOPPE will be sufficiently flexible for most applications. However, we have observed that there appears to be a limit on total waveform memory allowed by our GE scanner: for example, the multi-waveform .mod file shown here appears to nearly reach the total memory limit. Fig. S3. Example of a relatively complex pulse sequence that is not easily implemented using traditional programming techniques: Arterial Spin Labeling with stack-of-spirals readout. Following a (velocity-selective) spin tagging pulse and a transit delay of a1/41.3 sec, a train of alternating RF excitation and data readout modules are played out (total duration a1/40.7 sec). kz (partition) encode ordering is center-out (not shown). The flip angle is increased to maintain constant signal following each excitation. For a given readout repetition interval and assuming tissue T1 of gray matter at 3T, we obtained the optimal flip angle schedule using the Matlab function fmincon. Implementing such a sequence using traditional programming techniques would be relatively laborious, and would in any case likely require the ASL tagging pulse, flip angle schedule, and perhaps the spiral readouts to be loaded from external files. Fig. S4. Another example of a relatively complex pulse sequence that is not easily implemented using traditional programming techniques: A set of 12 triangular readout gradients used to measure gradient impulse response function, as implemented in (15). Although the waveforms differ only by their time to peak (ranging from 50 to 160 I1/4s in 10 I1/4s increments), there is no direct way to encode these waveforms programmatically during run-time. In TOPPE, one can either associate each waveform with its own .mod file, or load all 12 waveforms into a single module (after zero-padding to ensure equal waveform duration).

Italy

Byline: Vincenzo Abbate, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit Naples, University of Naples 'Federico II,' Naples; Giorgio Iaconetta, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit Naples, University of Naples 'Federico II,' Naples; Luigi Califano, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit Naples, University of Naples 'Federico II,' Naples; Antonio Pansini, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit Naples, University of Naples 'Federico II,' Naples; Paola Bonavolonta, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit Naples, University of Naples 'Federico II,' Naples; Antonio Romano, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit Naples, University of Naples 'Federico II,' Naples; Giovanni Salzano, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit Naples, University of Naples 'Federico II,' Naples; Teresa Somma, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit Naples, University of Naples 'Federico II,' Naples; Luca D'Andrea, Neurosurgery Department Salerno, University of Salerno, Fisciano, Italy.; Giovanni Dell'Aversana Orabona, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit Naples, University of Naples 'Federico II,' Naples Abstract BACKGROUND:: Restoring the orbital cavity integrity in orbital floor defects is a challenging issue due to the anatomical complexity of the floor's surface. This is a showcase for technical description of a novel 'in house' rapid prototyping protocol aimed to customize implant for orbital floor reconstruction. METHODS:: The authors present 4 cases to show our Computer-aided-design and Computer-aided-manufacturing digital workflow. The system was based on a 3D-printed press that; through a virtually designed mold, was used to conform a patient specific titanium mesh for orbital floor reconstruction. RESULTS:: The merging procedure analysis by iPlan Cranial 3.0 (Brainlab, Munich, Germany) highlighted a 0.71 [+ or -] 0.23 mm (P <0.05) discrepancy in a point-to-point superimposition between the digital planned reconstruction and the real in vivo result. CONCLUSIONS:: The authors expect that this technique will reduce operative time and cost however further study and larger series may better define the applicability in everyday surgical practice.

Cheek-bone -- Injuries, Cheek-bone -- Care and treatment, Postoperative care -- Patient outcomes, and Face shields -- Testing

Byline: Giovanni Dell'Aversana Orabona, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit; Vincenzo Abbate, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit; Fabio Maglitto, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit; Umberto Committeri, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit; Giovanni Improta, Department of Public Health, University of Naples 'Federico II,' Naples, Italy.; Paola Bonavolonta, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit; Alfonso Reccia, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit; Teresa Somma, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Neurosurgery Unit, University of Naples 'Federico II,' Naples; Giorgio Iaconetta, Neurosurgery Department, University of Salerno; Luigi Califano, Department of Neurosciences, Reproductive and Odontostomatological Sciences, Maxillofacial Surgery Unit Abstract Zygomatic fractures account for 10% to 15% of all facial fractures. The surgical management of isolated zygomatic arch fractures usually requires open reduction treatment without fixation through an intraoral access. Therefore, the main problem in the non-fixed treatment of zygomatic arch fractures is related to the difficulty in obtaining a stable reduction for a period long enough to guarantee the physiological bone healing process. We propose an innovative 'in-house' rapid prototyping (RP) protocol for the 3D-zygoma mask manufacture of a patient-specific protective device to apply after zygomatic arch fracture reduction. Our study includes 16 consecutive patients who underwent surgical open reduction for an isolated zygoma fracture without fixation between January 2017 and February 2018. The patients received regular postoperative checks at weeks 1 and 2. Before the device was removed, a multiple choice questionnaire was administered to measure the degree of wearability of the mask. The estimated cost of the production is around &OV0556;5 per case and the construction time is around 90 minutes. Based on the encouraging results, obtained in our experience, we hope that other studies can be conducted to confirm our procedure and improve its functionality in the field of facial trauma.