This work illustrates a new approach to field-aligned coordinates for plasma turbulence simulations which is not based on flux variables. The method employs standard Cartesian or polar coordinates to ...discretize the fields. Parallel derivatives are computed directly along a coordinate that follows the local field, and poloidal derivatives are computed in the original Cartesian frame. Several advantages of this approach are presented. The tests on a drift-wave model demonstrate that the method is well suited to exploit the flute property of small parallel gradients by minimizing the number of degrees of freedom needed to treat a given problem in an accurate and efficient manner.
Midface hypoplasia in syndromic craniosynostosis (SC) may lead to serious respiratory issues. The aim of this study was to analyse the morphometric correlation between midface and cranial base ...parameters in paediatric SC patients in order to formulate predictive regression models. The computed tomography scans of 18 SC patients and 20 control were imported into Materialise Mimics Medical version 21.0 software for the measurement of multiple craniofacial landmarks and correlation analysis. The results showed a strong correlation of anterior cranial base (SN), posterior cranial base (SBa), and total cranial base (NBa) (r = 0.935) to maxilla length and width (ZMR–ZML) (r = 0.864). The model of NBa = − 1.554 + 1.021(SN) + 0.753(SBa) with R2 = 0.875 is proposed to demonstrate the development of the cranial base that causes a certain degree of midface hypoplasia in SC patients. The formula is supported using a prediction model of ZMR–ZML = 5.762 + 0.920(NBa), with R2 = 0.746. The mean absolute difference and standard deviation between the predicted and true NBa and ZMR–ZML were 2.08 ± 1.50 mm and 3.11 ± 2.32 mm, respectively. The skeletal growth estimation models provide valuable foundation for further analysis and potential clinical application.
Arthrocentesis and arthroscopy are relatively safe treatments for arthrogenic temporomandibular disorders. Hands-on training in both procedures is essential for surgeons to become competent. In this ...study, a three-dimensional (3D) temporomandibular joint (TMJ) prototype was developed at a relatively low cost, and arthrocentesis and arthroscopy were performed successfully on the model. Despite its limitations, this model is a viable adjunct to TMJ surgical training and can be fabricated easily by any training centre with a 3D printer.
Isolated traumatic maxillofacial injury without concomitant brain injury may cause delayed post-concussive symptoms. Early identification allows optimal diagnosis, prognostication, and therapeutic ...intervention. The aim of this prospective observational study was to investigate longitudinal microstructural changes of the white matter (WM) tracts based on diffusion tensor imaging (DTI) indices in patients with isolated maxillofacial injuries, immediately and 6 months post-trauma, and to correlate these DTI indices with neuropsychological changes observed. Twenty-one patients with isolated maxillofacial injuries and 21 age-matched controls were recruited. DTI was performed and indices were calculated for 50 WM tracts. The neuropsychological evaluation was done using the screening module of the Neuropsychological Assessment Battery. Patients were subjected to repeat DTI and neuropsychological evaluation at 6 months post-trauma. Reduced fractional anisotropy (FA) and increased median (MD) and radial diffusivity (RD) in the acute phase were seen in major association, projection, and commissural fibre bundles, indicative of vasogenic oedema. These changes correlated with attention and executive function deficits in the acute phase, as well as improvement in memory and visuospatial function in the chronic phase. Isolated maxillofacial trauma patients develop WM microstructural damage, which may impair cognitive performance acutely and over time. DTI indices can serve as predictive imaging biomarkers for long-term cognitive deficits in isolated maxillofacial injuries.
We present a portable platform, called PIC_ENGINE, for accelerating Particle-In-Cell (PIC) codes on heterogeneous many-core architectures such as Graphic Processing Units (GPUs). The aim of this ...development is efficient simulations on future exascale systems by allowing different parallelization strategies depending on the application problem and the specific architecture. To this end, this platform contains the basic steps of the PIC algorithm and has been designed as a test bed for different algorithmic options and data structures. Among the architectures that this engine can explore, particular attention is given here to systems equipped with GPUs. The study demonstrates that our portable PIC implementation based on the OpenACC programming model can achieve performance closely matching theoretical predictions. Using the Cray XC30 system, Piz Daint, at the Swiss National Supercomputing Centre (CSCS), we show that PIC_ENGINE running on an NVIDIA Kepler K20X GPU can outperform the one on an Intel Sandy bridge 8-core CPU by a factor of 3.4.
Our aim was to summarise current published evidence about the prognosis of various techniques of craniofacial distraction osteogenesis, particularly its indications, protocols, and complications. ...Published papers were acquired from online sources using the keywords “distraction osteogenesis”, “Le Fort III”, “monobloc”, and “syndromic craniosynostosis” in combination with other keywords, such as “craniofacial deformity” and “midface”. The search was confined to publications in English, and we followed the guidelines of the PRISMA statement. We found that deformity of the skull resulted mainly from Crouzon syndrome. Recently craniofacial distraction has been achieved by monobloc distraction osteogenesis using an external distraction device during childhood, while Le Fort III distraction osteogenesis was used in maturity. Craniofacial distraction was indicated primarily to correct increased intracranial pressure, exorbitism, and obstructive sleep apnoea in childhood, while midface hypoplasia was the main indication in maturity. Overall the most commonly reported complications were minor inflammatory reactions around the pins, and anticlockwise rotation when using external distraction systems. The mean amount of bony advancement was 12.3mm for an external device, 18.6mm for an internal device and 18.7mm when both external and internal devices were used. Treatment by craniofacial distraction must be validated by long-term studies as there adequate data are lacking, particularly about structural relapse and the assessment of function.
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