Simulation of macrosegregation benchmark on a non-uniform computational node arrangement with a meshless method

An application of a meshless numerical method on a macrosegregation benchmark case is developed in the present paper. The test case is solidification in 2D rectangular cavity, filled with liquid metal and chilled from both sides. This is a highly non-linear problem due to a strong coupling of the macroscopic transport equations with the microsegregation model. The main result is the macrosegregation pattern of the solidified metal Al4.5wt%Cu alloy is used for evaluation of the problem. The model uses diffuse approximate meshless method with the second-order polynomial basis for spatial integration and explicit time-stepping. Simulations are performed on uniform and non-uniform computational node arrangements and compared to each other. The results on uniform and non-uniform node arrangements show a very good matching with the finite volume method results and results based on radial basis function collocation method. This shows that diffuse approximate method based on non-uniform node arrangements can be used for solving macrosegregation problems

Simulation of macrosegregation in low-frequency electromagnetic casting by a meshless method

The novel use of a meshless numerical approach for simulation of macrosegregation in the low-frequency electromagnetic casting is presented along with the analysis of the simulation results. The casting model includes a coupled set of mass, momentum, energy, and species conservation equations. Lorentz force is computed with the induction equation and used in the solidification model. The coupled physical model is solved in cylindrical coordinate system and can be used to model aluminium alloy billet production. Explicit scheme is used for the temporal discretization, while the meshless diffuse approximate method is used for the spatial discretization. The method is localized with subdomains containing 14 local nodes. The Gaussian weight is used in the weighted least squares minimization. Furthermore, the Gaussian is shifted upstream, when an upwind effect is required in order to increase the convection stability. Direct chill casting under the influence of electromagnetic field (EMF) is simulated for various electric amplitudes and currents. The material properties of Al-5.25wt%Cu are used. The casting parameters and material properties are constant in all presented simulations, while EMF is turned off in some cases in order to study its effect on solidification. The results show that EMF has a large effect on the melt-flow and solidification. Oscillatory, instead of a steadystate, solution is obtained in case of certain geometries in EMF casting. The effect of EMF is hard to predict without the use of numerical simulations, due to strong coupled effects of casting geometry, casting parameters, and EMF parameters. This shows the need for numerical modelling of this strongly coupled problem for its better understanding

Folate Deficiency in May-Thurner Syndrome

May–Thurner Syndrome (MTS) is a condition defined by an anatomical variant that results in the compression of the left common iliac vein by the right common iliac artery. This case report describes MTS in a Hispanic female with folate deficiency. 44-year-old Nicaraguan female who is a lifelong nonsmoker without any past medical history presented with left leg pain and swelling for seven days. The patient stated that her whole left leg was edematous without erythema. No recent travel, trauma, surgery or immobilization of the lower extremity. Initial vitals on presentation were unremarkable. Physical exam revealed a tender swollen of left leg from ankle to the thigh. CBC showed WBC 16.2, hemoglobin 8.9, MCV 66, and platelets 295. BMP was normal. D-dimer was 6589. PT/INR 1.1 and 11.5. PTT 21.8. Doppler ultrasound of left lower extremity showed extensive DVT. CT of abd/pelvis with contrast showed May-Thurner lesion. Venogram was performed and a 5-French infusion catheter was placed with tPA infusion. Angioplasty and two overlapping 14 mm Bard Luminexx 60 mm Nitinol self-expanding stents were successfully positioned. The incidence of MTS is in the 30%, but DVT associated from MTS is around 2% with over 60% of patients having a hypercoagulable state. In our patient, thrombophilia work-up was negative. However, the patient had a folate deficiency which is an independent risk factor for venous thrombosis

Yolk Sac TumorMasquerading AsPericarditis: A Case Report

Introduction:Yolk sac tumor is a rare form of a germ cell tumor (GCT).This case report describes an unusual presentation of a yolk sac tumor with pericarditis, pericardial effusionand bilateral microlithiasis (MT) in a young Vietnamese male with extragonadal GCT in the anterior mediastinum. Presentation of Case:A 23-year-old Vietnamese male with one-pack year smoking history, but no other significant past medical history presented with nonproductive cough and pleuritic chest pain for 2 weeks. Chest pain was described as sharp and localized to the right-side of his substernal area. B-symptoms were present for 1 month and included: weight loss of 10lbs, night sweats and fever.Physical exam showeddiminished breath sounds on the right side of the chest w/o accessory muscle use. CT of the chest revealed a large 14 cm round mass in the right middle lobe with possible extension to the mediastinum, moderate right pleural effusion and pericardial effusion.EKG showed a pattern consistent with pericarditis. Biopsy of the mediastinal mass was consistent with yolk sac tumor. LDH was 543, AFP 7200, and β-HCG2.Testicular ultrasound did not find any testicular masses, but there was bilateral testicular microlithiasis. The patient was started on BEP (Bleomycin + Etoposide + Cisplatin) chemotherapy with subsequent thoracotomy and mass resection.Conclusion:Younger patients presenting with pleural effusions and pericarditis need a detailed history and physical examination in order to diagnosea yolk sac tumor

Delayed Severe Drug Induced Cholestasis After Anabolic Steroids Exposure

Anabolic steroids therapy is linked to a distinctive form of acute cholestasis that generally arises within 1 to 4 months of starting therapy but may be delayed to as long as 6 to 24 months in some reported cases. We are presenting an unusual case where acute cholestasis happened 5 weeks after discontinuing short course (7 days) of anabolic steroids. A 20-year-old African American male without significant past medical history presented with jaundice, mild nausea and generalized pruritis. He admitted to self-initiation of oral Stanozolol 40 mg daily for 7-days about 5 weeks before his admission. No prior incidence and no significant alcohol use. Vitals signs unremarkable and physical exam was unremarkable except for jaundice and sclera icterus. No hepatosplenomegaly. Liver function profile with ALT 44 IU/L, AST 72 IU/L, ALP 266 IU/L, & total bilirubin of 21.4 mg/Dl. Extensive hepatitis workup was negative and a CT-guided liver biopsy was performed which showed marked hepatocanalicular cholestasis. This is reflective of drug induced cholestasis. Our case highlights the possibility of delayed liver injury even after a short anabolic steroids course which typically happen while taking the medication for an extended period (more than 1 month)

Simulation of multiscale industrial solidification problem under influence of electromagnetic field by meshless method

Simulation and control of macrosegregation, deformation and grain size under  electromagnetic (EM) processing conditions is important in industrial solidification systems,  since it influences the quality of the casts and consequently the whole downstream processing  path. Respectively, a multiphysics and multiscale model is developed for solution of Lorentz  force, temperature, velocity, concentration, deformation and grain structure of the casts. The  mixture equations with lever rule, linearized phase diagram, and stationary thermoelastic solid  phase are assumed, together with EM induction equation for the field imposed by the low  frequency EM field or Ohm’s law and charge conservation equation for stationary EM field.  Turbulent effects are incorporated through the solution of a low-Re turbulence model. The  solidification system is treated by the mixture-continuum model, where the mushy zone is  modeled as a Darcy porous media with Kozeny-Karman permeability relation and columnar  solid phase moving with the system velocity. Explicit diffuse approximate meshless solution  procedure [1] is used for solving the EM field, and the explicit local radial basis function  collocation  method  [2]  is  used  for  solving  the  coupled  transport  phenomena  and  thermomechanics  fields.  Pressure-velocity  coupling  is  performed  by  the  fractional  step  method [3]. The point automata method with modified KGT model is used to estimate the  grain structure [4] in a post-processing mode. Thermal, mechanical, EM and grain structure  outcomes of the model are demonstrated for low frequency EM casting of round aluminium  billets. A systematic study of the complicated influences of the process parameters on the  microstructure can be investigated by the model, including intensity and frequency of the  electromagnetic field

Fine motor, gross motor, and social independence skills among stunted and non-stunted children

Child growth and development are important aspects of the quality of human capital in future. This study aimed to examine the association between stunting and fine motor, gross motor, and social independence development among children under the age of five years old. We included a total of 525 children from district level survey in Sedayu Subdistrict, Yogyakarta, Indonesia, for further analysis. Stunting was associated with fine motor (OR = 3.45; 95% CI: 1.22–9.76) and social independence (OR = 7.09; 95% CI: 2.01–25.01), but not gross motor skill (OR = 2.43; 95% CI: 0.67–8.81). Performance ratios of fine motor (p = 0.02) and social independence (p = 0.01) skills were also higher among non-stunted children compared to stunted children

BlessemFlood21: Advancing Flood Analysis with a High-Resolution Georeferenced Dataset for Humanitarian Aid Support

Floods are an increasingly common global threat, causing emergencies and severe damage to infrastructure. During crises, organisations such as the World Food Programme use remotely sensed imagery, typically obtained through drones, for rapid situational analysis to plan life-saving actions. Computer Vision tools are needed to support task force experts on-site in the evaluation of the imagery to improve their efficiency and to allocate resources strategically. We introduce the BlessemFlood21 dataset to stimulate research on efficient flood detection tools. The imagery was acquired during the 2021 Erftstadt-Blessem flooding event and consists of high-resolution and georeferenced RGB-NIR images. In the resulting RGB dataset, the images are supplemented with detailed water masks, obtained via a semi-supervised human-in-the-loop technique, where in particular the NIR information is leveraged to classify pixels as either water or non-water. We evaluate our dataset by training and testing established Deep Learning models for semantic segmentation. With BlessemFlood21 we provide labeled high-resolution RGB data and a baseline for further development of algorithmic solutions tailored to flood detection in RGB imagery

Effect of cumulative dose of brentuximab vedotin maintenance in relapsed/refractory classical Hodgkin lymphoma after autologous stem cell transplant: an analysis of real-world outcomes

Sixteen cycles of Brentuximab vedotin (BV) after autologous stem cell transplant (ASCT) in high-risk relapsed/refractory classical Hodgkin lymphoma demonstrated an improved 2-year progression-free survival (PFS) over placebo. However, most patients are unable to complete all 16 cycles at full dose due to toxicity. This retrospective, multicenter study investigated the effect of cumulative maintenance BV dose on 2-year PFS. Data were collected from patients who received at least one cycle of BV maintenance after ASCT with one of the following high-risk features: primary refractory disease (PRD), extra-nodal disease (END), or relapse 75% of the planned total cumulative dose, cohort 2 with 51-75% of dose, and cohort 3 with ≤50% of dose. The primary outcome was 2-year PFS. A total of 118 patients were included. Fifty percent had PRD, 29% had RL<12, and 39% had END. Forty-four percent of patients had prior exposure to BV and 65% were in complete remission before ASCT. Only 14% of patients received the full planned BV dose. Sixty-one percent of patients discontinued maintenance early and majority of those (72%) were due to toxicity. The 2-year PFS for the entire population was 80.7%. The 2-year PFS was 89.2% for cohort 1 (n=39), 86.2% for cohort 2 (n=33), and 77.9% for cohort 3 (n=46) (P=0.70). These data are reassuring for patients who require dose reductions or discontinuation to manage toxicity