bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Numerical Study on the Keyhole Formation During Laser Powder Bed Fusion Process
Authors: Shrestha Subin , Chou Y. Kevin 
Published: November 2019

Abstract
The dynamic phenomenon of a melt pool during the laser powder bed fusion (LPBF) process is complex and sensitive to process parameters. As the energy density input exceeds a certain threshold, a huge vapor depression may form, known as the keyhole. This study focuses on understanding the keyhole behavior and related pore formation during the LPBF process through numerical analysis. For this purpose, a thermo-fluid model with discrete powder particles is developed. The powder distribution, obtained from a discrete element method (DEM), is incorporated into the computational domain to develop a 3D process physics model using FLOW-3D. The melt pool formation during the conduction mode and the keyhole mode of melting has been discerned and explained. The high energy density leads to the formation of a vapor column and consequently pores under the laser scan track. Further, the keyhole shape resulted from different laser powers and scan speeds is investigated. The numerical results indicated that the keyhole size increases with the increase in the laser power even with the same energy density. The keyhole becomes stable at a higher power, which may reduce the occurrence of pores during laser scanning.
Powder-Scale Meshfree Simulations of Powder Bed Fusion Based Additive Manufacturing Processes
Authors: Fan Zongyue , Wang Hao , Li Bo 
Published: November 2019

Abstract
We present a powder-scale meshfree direct numerical simulation (DNS) capability for the powder bed fusion (PBF) based additive manufacturing (AM) processes using the novel Hot Optimal Transportation Meshfree (HOTM) method. The HOTM method is an incremental Lagrangian meshfree computational framework for materials behaviors under extreme thermomechanical loading conditions, which combines the Optimal Transportation Meshfree (OTM) method and the variational thermomechanical constitutive updates. The realistic multi-layer powder bed geometry is modeled explicitly in the HOTM simulations based on experimental data. A phase-aware constitutive model is developed to predict the phase change and multiphase mixing during the PBF AM processes automatically. The governing equations including the linear momentum and energy conservation equations are solved for the multiphase flow simultaneously to predict the deformation, temperature and local state of the powder particles. The powder-scale DNS is employed to study the influence of various laser powers on the melt pool thermodynamics.
A State-of-the-Art Review on Aerosol Jet Printing (AJP) Additive Manufacturing Process
Authors: Salary Roozbeh Ross , Lombardi Jack P. , Weerawarne Darshana L. , Rao Prahalad K. , Poliks Mark D. 
Published: November 2019

Abstract
The goal of this work is to forward a comprehensive framework, relating to the most recent research works carried out in the area of flexible and hybrid electronics (FHE) fabrication with the aid of aerosol jet printing (AJP) additive manufacturing process. In pursuit of this goal, the objective is to review and classify a wide range of articles, published recently, concerning various aspects of AJP-based device fabrication, such as material synthesis, process monitoring, and control.
AJP has recently emerged as the technique of choice for integration as well as fabrication of a broad spectrum of electronic components and devices, e.g., interconnects, sensors, transistors, optical waveguides, quantum dot arrays, photodetectors, and circuits. This is preeminently because of advantages engendered by AJP process. AJP not only allows for high-resolution deposition of microstructures, but also accommodates a wide renege of ink viscosity. However, AJP is intrinsically complex and prone to gradual drifts of the process output (stemming from ink chemistry and formulation). Consequently, a large number of research works in the literature has focused on in situ process characterization, real-time monitoring, and closed-loop control with the aim to make AJP a rapid, reliable, and robust additive manufacturing method for the manufacture of flexible and hybrid electronic devices. It is expected that the market for flexible electronics will be worth over $50 billion by 2020 [1].
Computational Foundations for Using Three Degrees of Freedom Build Platforms to Enable Supportless Extrusion-Based Additive Manufacturing
Authors: Bhatt Prahar M. , Malhan Rishi K. , Gupta Satyandra K. 
Published: November 2019

Abstract
Extrusion-based additive manufacturing systems usually use three degrees of freedom extrusion tools to perform the deposition operation. This requires the use of support structures to deposit structures with overhang features. The use of support structures can be avoided by adding degrees of freedom to the build platform. The elimination of build structures can offer benefits in terms of reduction of build time and elimination of postprocessing costs. This paper demonstrates that the use of three degrees of freedom build platform enables printing of complex shapes without support structures. We present computational foundations for generating paths and trajectories for synchronizing the motion of three degrees of freedom build platforms and three degrees of freedom extrusion tools. We report results on six different test parts in terms of reduction in build time, accuracy, and surface roughness.
Implementation of research evidence in orthopaedics: a tale of three trials
Authors: Reeves Katharine , Chan Samuel , Marsh Alastair , Gallier Suzy , Wigley Catrin , Khunti Kamlesh , Lilford Richard J 
Published: November 2019

ObjectiveTo examine implementation of evidence in orthopaedic practice following publication of the results of three pivotal clinical trials.DesignCase studies based on three orthopaedic trials funded in sequence by the National Institute for Health Research Health Technology Assessment (HTA) programme. These trials dealt with treatment of fractures of the humerus, radius and ankle, respectively. For each case study, we conducted time-series analyses to examine the relationship between publication of findings and the implementation (or not) of the findings.ResultsThe results of all three trials favoured the less expensive and less invasive option. In two cases, a change of practice, in line with the evidence that eventually emerged, preceded publication. Furthermore, the upturn in use of the intervention most supported by each of these two trials corresponded to the start of recruitment to the respective trial. The remaining trial failed to influence practice despite yielding clear-cut evidence.ConclusionsImplementation of results of all three HTA orthopaedic trials favoured the less expensive and less invasive option. In two of the three studies, a change in practice, in line with the evidence that eventually emerged, preceded publication of that evidence. A trend or a change in practice, at around the start of the trial, indicates that the direction of causation opposes our hypothesis that publication of trial findings would lead to changes in practice. Our results provide provocative insight into the nuanced topic of research and practice, but further qualitative work is needed to fully explain what led to the pre-emptive change in practice we observed and why there was no change in the third case.
Improving access to contraception through integration of family planning services into a multidrug-resistant tuberculosis treatment programme
Authors: Cornish Emily F , Hudson Jonathan , Sayers Ross , Loveday Marian 
Published: November 2019

ObjectivesMultidrug-resistant tuberculosis (MDR-TB) is a global public health priority. The advent of the World Health Organisation’s Short Course regimen for MDR-TB, which halves treatment duration, has transformed outcomes and treatment acceptability for affected patients. Bedaquiline, a cornerstone of the Short Course regimen, has unknown teratogenicity and the WHO therefore recommends reliable contraception for all female MDR-TB patients in order to secure eligibility for bedaquiline. We were concerned that low contraceptive uptake among female patients in our rural South African MDR-TB treatment programme could jeopardise their access to bedaquiline. We therefore conducted a service delivery improvement project that aimed to audit contraceptive use in female MDR-TB patients, integrate family planning services into MDR-TB care, and increase the proportion of female patients eligible for bedaquiline therapy.MethodsContraceptive use and pregnancy rates were audited in all female patients aged 13–50 years initiated on our MDR-TB treatment programme in 2016. We then implemented an intervention consisting of procurement of depot-medroxyprogesterone acetate (DMPA) for the MDR-TB unit and training of specialist MDR-TB nurses in administration of DMPA. The audit cycle was repeated for all female patients aged 13–50 years initiated on the programme in January–October 2017 (post-intervention).ResultsThe proportion of women on injectable contraceptives by the time of MDR-TB treatment initiation increased significantly in the post-intervention cohort (77.4% vs 23.9%, p<0.0001).ConclusionBy integrating contraceptive services into our MDR-TB programme we significantly increased contraceptive uptake, protecting women from the obstetric risks associated with pregnancy during MDR-TB treatment and maximising their eligibility for bedaquiline therapy.
A novel self-expanding primarily bioabsorbable braided flow-diverting stent for aneurysms: initial safety results
Authors: Jamshidi Mehdi , Rajabian Mahmoud , Avery Michael B , Sundararaj Uttandaraman , Ronsky Janet , Belanger Brooke , Wong John H , Mitha Alim P 
Published: November 2019

IntroductionThe advent of metal flow-diverting stents has provided neurointerventionalists with an option for treating aneurysms without requiring manipulations within the aneurysm sac. The large amount of metal in these stents, however, can lead to early and late thrombotic complications, and thus requires long-term antiplatelet agents. Bioabsorbable stents have been postulated to mitigate the risk of these complications. Here we present early data on the first self-expandable primarily bioabsorbable stent for aneurysms.MethodsBraided stents were developed using poly-L-lactic acid fibers with material surface area similar to metal flow diverters. Crush resistance force, hemolysis, and thrombogenicity were determined and compared with existing commercial devices. Stents were deployed in infra-renal rabbit aortas to determine angiographic side branch patency and to study neointima formation for a 1-month follow-up period.ResultsCrush resistance force was determined to be on the order of existing commercial devices. Hemolytic behavior was similar to existing metal devices, and thrombogenicity was lower than metal flow-diverting stents. A smooth neointimal layer was found over the absorbable stent surface and all covered side branches were patent at follow-up.ConclusionThe design of self-expanding primarily bioabsorbable flow-diverting stents is possible, and preliminary safety data is consistent with a favorable profile in terms of mechanical behavior, hemocompatibility, side branch patency, and histological effects. Additional in vitro and long-term in vivo studies are in progress and will help determine aneurysm occlusion rates and absorption characteristics of the stent.
Lund jet images from generative and cycle-consistent adversarial networks
Authors: Carrazza Stefano , Dreyer Frédéric A. 
Published: November 2019

AbstractWe introduce a generative model to simulate radiation patterns within a jet using the Lund jet plane. We show that using an appropriate neural network architecture with a stochastic generation of images, it is possible to construct a generative model which retrieves the underlying two-dimensional distribution to within a few percent. We compare our model with several alternative state-of-the-art generative techniques. Finally, we show how a mapping can be created between different categories of jets, and use this method to retroactively change simulation settings or the underlying process on an existing sample. These results provide a framework for significantly reducing simulation times through fast inference of the neural network as well as for data augmentation of physical measurements.
The Weisfeiler--Leman Dimension of Planar Graphs Is at Most 3
Authors: Kiefer Sandra , Ponomarenko Ilia , Schweitzer Pascal 
Published: November 2019

We prove that the Weisfeiler--Leman (WL) dimension of the class of all finite planar graphs is at most 3. In particular, every finite planar graph is definable in first-order logic with counting using at most 4 variables. The previously best-known upper bounds for the dimension and number of variables were 14 and 15, respectively.
First, we show that, for dimension 3 and higher, the WL-algorithm correctly tests isomorphism of graphs in a minor-closed class whenever it determines the orbits of the automorphism group of every arc-colored 3-connected graph belonging to this class.
Then, we prove that, apart from several exceptional graphs (which have WL-dimension at most 2), the individualization of two appropriately chosen vertices of a colored 3-connected planar graph followed by the one-dimensional WL-algorithm produces the discrete vertex partition. This implies that the three-dimensional WL-algorithm determines the orbits of arc-colored 3-connected planar graphs.
As a byproduct of the proof, we get a classification of the 3-connected planar graphs with fixing number 3.
Improved endothelial-dependent and endothelial-independent skin vasodilator responses following remote ischemic preconditioning
Authors: Kim Jahyun , Franke Warren D. , Lang James A. 
Published: November 2019

One week of daily remote ischemic preconditioning (RIPC) improves cutaneous vasodilatory (VD) function. However, the underlying mechanisms and the number of sessions needed to optimize this adaptive response remain unclear. We hypothesized that the responses to localized heating of the skin will be greater after 2 wk as opposed to 1 wk of RIPC. Furthermore, 2 wk of repeated RIPC will augment cutaneous VD responses to thermal and pharmacological stimuli. In methods, twenty-four participants (24 ± 2 yr; 13 men, 11 women) performed repeated RIPC (7 daily sessions over 1 wk, n = 11; 12 sessions over 2 wk, n = 13), consisting of four repetitions of 5 min of arm blood flow occlusion separated by 5 min reperfusion. Laser speckle contrast imaging was used to measure skin blood flow responses, in perfusion units (PU), to local heating (Tloc = 42°C), acetylcholine (ACh), and sodium nitroprusside (SNP) before and after repeated RIPC. Data were expressed as cutaneous vascular conductance (CVC, in PU/mmHg). In results, the VD response to local heating increased after RIPC (∆CVC from baseline; 1 wk: 0.94 ± 0.11 to 1.19 ± 0.15, 2 wk: 1.18 ± 0.07 to 1.33 ± 0.10 PU/mmHg; P < 0.05) but the ∆CVC did not differ between weeks. SNP-induced VD increased after 2 wk of RIPC (∆CVC; 0.34 ± 0.07 to 0.63 ± 0.11 PU/mmHg; P < 0.05), but ACh-induced VD did not. In conclusion, repeated RIPC improves local heating- and SNP-mediated cutaneous VD. When compared with 1 wk of RIPC, 2 wk of RIPC does not induce further improvements in cutaneous VD function. NEW & NOTEWORTHY Repeated RIPC increases the cutaneous vasodilatory response to local heating and to sodium nitroprusside but not to acetylcholine. Thus, endothelial-independent and local heating-mediated cutaneous vasodilation are improved following RIPC. However, 2 wk of RIPC sessions are not more effective than 1 wk of RIPC sessions in enhancing local heating-mediated cutaneous vasodilation.
Determinants of the esophageal-pleural pressure relationship in humans
Authors: Pasticci Iacopo , Cadringher Paolo , Giosa Lorenzo , Umbrello Michele , Formenti Paolo , Macri Matteo M. , Busana Mattia , Bonifazi Matteo , Romitti Federica , Vassalli Francesco , Cressoni Massimo , Quintel Michael , Chiumello Davide , Gattinoni Luciano 
Published: November 2019

Esophageal pressure has been suggested as adequate surrogate of the pleural pressure. We investigate after lung surgery the determinants of the esophageal and intrathoracic pressures and their differences. The esophageal pressure (through esophageal balloon) and the intrathoracic/pleural pressure (through the chest tube on the surgery side) were measured after surgery in 28 patients immediately after lobectomy or wedge resection. Measurements were made in the nondependent lateral position (without or with ventilation of the operated lung) and in the supine position. In the lateral position with the nondependent lung, collapsed or ventilated, the differences between esophageal and pleural pressure amounted to 4.4 ± 1.6 and 5.1 ± 1.7 cmH2O. In the supine position, the difference amounted to 7.3 ± 2.8 cmH2O. In the supine position, the estimated compressive forces on the mediastinum were 10.5 ± 3.1 cmH2O and on the iso-gravitational pleural plane 3.2 ± 1.8 cmH2O. A simple model describing the roles of chest, lung, and pneumothorax volume matching on the pleural pressure genesis was developed; modeled pleural pressure = 1.0057 × measured pleural pressure + 0.6592 ( r2 = 0.8). Whatever the position and the ventilator settings, the esophageal pressure changed in a 1:1 ratio with the changes in pleural pressure. Consequently, chest wall elastance (Ecw) measured by intrathoracic (Ecw = ΔPpl/tidal volume) or esophageal pressure (Ecw = ΔPes/tidal volume) was identical in all the positions we tested. We conclude that esophageal and pleural pressures may be largely different depending on body position (gravitational forces) and lung-chest wall volume matching. Their changes, however, are identical. NEW & NOTEWORTHY Esophageal and pleural pressure changes occur at a 1:1 ratio, fully justifying the use of esophageal pressure to compute the chest wall elastance and the changes in pleural pressure and in lung stress. The absolute value of esophageal and pleural pressures may be largely different, depending on the body position (gravitational forces) and the lung-chest wall volume matching. Therefore, the absolute value of esophageal pressure should not be used as a surrogate of pleural pressure.
The effects of forearm position and contraction intensity on cortical and spinal excitability during a submaximal force steadiness task of the elbow flexors
Authors: Yacyshyn Alexandra F. , Kuzyk Samantha , Jakobi Jennifer M. , McNeil Chris J. 
Published: November 2019

Elbow flexor force steadiness is less with the forearm pronated (PRO) compared with neutral (NEU) or supinated (SUP) and may relate to neural excitability. Although not tested in a force steadiness paradigm, lower spinal and cortical excitability was observed separately for biceps brachii in PRO, possibly dependent on contractile status at the time of assessment. This study aimed to investigate position-dependent changes in force steadiness as well as spinal and cortical excitability at a variety of contraction intensities. Thirteen males (26 ± 7 yr; means ± SD) performed three blocks (PRO, NEU, and SUP) of 24 brief (~6 s) isometric elbow flexor contractions (5, 10, 25 or 50% of maximal force). During each contraction, transcranial magnetic stimulation or transmastoid stimulation was delivered to elicit a motor-evoked potential (MEP) or cervicomedullary motor-evoked potential (CMEP), respectively. Force steadiness was lower in PRO compared with NEU and SUP ( P ≤ 0.001), with no difference between NEU and SUP. Similarly, spinal excitability (CMEP/maximal M wave) was lower in PRO than NEU (25 and 50% maximal force; P ≤ 0.010) and SUP (all force levels; P ≤ 0.004), with no difference between NEU and SUP. Cortical excitability (MEP/CMEP) did not change with forearm position ( P = 0.055); however, a priori post hoc testing for position showed excitability was 39.8 ± 38.3% lower for PRO than NEU at 25% maximal force ( P = 0.006). The data suggest that contraction intensity influences the effect of forearm position on neural excitability and that reduced spinal and, to a lesser extent, cortical excitability could contribute to lower force steadiness in PRO compared with NEU and SUP. NEW & NOTEWORTHY To address conflicting reports about the effect of forearm position on spinal and cortical excitability of the elbow flexors, we examine the influence of contraction intensity. For the first time, excitability data are considered in a force steadiness context. Motoneuronal excitability is lowest in pronation and this disparity increases with contraction intensity. Cortical excitability exhibits a similar pattern from 5 to 25% of maximal force. Lower corticospinal excitability likely contributes to relatively poor force steadiness in pronation.
Gain-of-Function Mutant p53 R273H Interacts with Replicating DNA and PARP1 in Breast Cancer
Authors: Xiao Gu , Lundine Devon , Annor George K. , Canar Jorge , Ellison Viola , Polotskaia Alla , Donabedian Patrick L. , Reiner Thomas , Khramtsova Galina F. , Olopade Olufunmilayo I. , Mazo Alexander , Bargonetti Jill 
Published: November 2019

Abstract

Over 80% of triple-negative breast cancers (TNBC) express mutant p53 (mtp53) and some contain oncogenic gain-of-function (GOF) p53. We previously reported that GOF mtp53 R273H upregulates the chromatin association of mini chromosome maintenance (MCM) proteins MCM2-7 and PARP and named this the mtp53–PARP–MCM axis. In this study, we dissected the function and association between mtp53 and PARP using a number of different cell lines, patient-derived xenografts (PDX), tissue microarrays (TMA), and The Cancer Genome Atlas (TCGA) database. Endogenous mtp53 R273H and exogenously expressed R273H and R248W bound to nascent 5-ethynyl-2´-deoxyuridine-labeled replicating DNA. Increased mtp53 R273H enhanced the association of mtp53 and PARP on replicating DNA. Blocking poly-ADP-ribose gylcohydrolase also enhanced this association. Moreover, mtp53 R273H expression enhanced overall MCM2 levels, promoted cell proliferation, and improved the synergistic cytotoxicity of treatment with the alkylating agent temozolomide in combination with the PARP inhibitor (PARPi) talazoparib. Staining of p53 and PARP1 in breast cancer TMAs and comparison with the TCGA database indicated a higher double-positive signal in basal-like breast cancer than in luminal A or luminal B subtypes. Higher PARP1 protein levels and PAR proteins were detected in mtp53 R273H than in wild-type p53-expressing PDX samples. These results indicate that mtp53 R273H and PARP1 interact with replicating DNA and should be considered as dual biomarkers for identifying breast cancers that may respond to combination PARPi treatments.

Significance:
p53 gain-of-function mutant 273H and PARP1 interact with replication forks and could serve as potential biomarkers for breast cancer sensitivity to PARP inhibitors.