PArallel, Robust, Interface Simulator (PARIS)

Paris (PArallel, Robust, Interface Simulator) is a finite volume code for simulations of immiscible multifluid or multiphase flows. It is based on the "one-fluid" formulation of the Navier-Stokes equations where different fluids are treated as one material with variable properties, and surface tension is added as a singular interface force. The fluid equations are solved on a regular structured staggered grid using an explicit projection method with a first-order or second-order time integration scheme. The interface separating the different fluids is tracked by a Front-Tracking (FT) method, where the interface is represented by connected marker points, or by a Volume-of-Fluid (VOF) method, where the marker function is advected directly on the fixed grid. Paris is written in Fortran95/2002 and parallelized using MPI and domain decomposition. It is based on several earlier FT or VOF codes such as Ftc3D, Surfer or Gerris. These codes and similar ones, as well as Paris, have been used to simulate a wide range of multifluid and multiphase flows

Increased percentage of L-selectin+ and ICAM-1+ peripheral blood CD4+/CD8+ T cells in active Graves' ophthalmopathy.

The purpose of the study was to evaluate the percentage of CD4+/CD8+ peripheral T cells expressing CD62L+ and CD54+ in patients with Graves' disease and to assess if these estimations could be helpful as markers of active ophthalmopathy. The study was carried out in 25 patients with Graves' disease (GD) divided into 3 groups: 1/ 8 patients with active Graves' ophthalmopathy (GO) (CAS 3-6, GO complaints pound 1 year), 2/ 9 patients with hyperthyroid GD without symptoms of ophthalmopathy (GDtox) and 3/ 8 patients with euthyroid GD with no GO symptoms (GDeu). The control group consisted of 15 healthy volunteers age and sex matched to groups 1-3. The expression of lymphocyte adhesion molecules was evaluated by using three-color flow cytometry. In GO group the percentage of CD8+CD54+, CD8+CD62L+, CD4+CD54+ and CD4+CD62L+ T cells was significantly higher as compared to controls (p<0.001, p<0.05, p<0.01, p<0.001 respectively). The percentage of CD8+CD54+ T lymphocytes was also elevated in GO group in comparison to hyperthyroid GD patients (p< 0.05). CD4+CD62L+ and CD8+CD54+ percentages were also increased in GDtox and GDeu as compared to controls. We found a positive correlation between the TSHRab concentration and the percentage of CD8+CD62L+ T cells in all studied groups (r= 0.39, p<0.05) and between the TSHRab level and CAS (r= 0.77, p<0.05). The increased percentage of CD8+CD54+ and CD8+CD62L+ T cells in patients with Graves' ophthalmopathy may be used as a marker of immune inflammation activity

Simultaneous ectopic adrenocorticotropic hormone syndrome and adrenal metastasis of a medullary thyroid carcinoma causing paraneoplastic Cushing's syndrome

Medullary thyroid carcinomas (MTC) constitute about 5 to 7 % of thyroid neoplasms. They originate from parafollicular C-cells which can secrete adrenocorticotropic hormone (ACTH) and/or corticotropin-releasing factor (CRF) in abnormally high concentrations, potentially causing paraneoplastic Cushing's Syndrome (CS)

Ectopic Cushing' syndrome caused by a neuroendocrine carcinoma of the mesentery

BACKGROUND: ACTH overproduction within the pituitary gland or ectopically leads to hypercortisolism. Here, we report the first case of Cushing' syndrome caused by an ectopic ACTH-secreting neuroendocrine carcinoma of the mesentery. Moreover, diagnostic procedures and pitfalls associated with ectopic ACTH-secreting tumors are demonstrated and discussed. CASE PRESENTATION: A 41 year-old man presented with clinical features and biochemical tests suggestive of ectopic Cushing's syndrome. First, subtotal thyroidectomy was performed without remission of hypercortisolism, because an octreotide scan showed increased activity in the left thyroid gland and an ultrasound revealed nodules in both thyroid lobes one of which was autonomous. In addition, the patient had a 3 mm hypoenhancing lesion of the neurohypophysis and a 1 cm large adrenal tumor. Surgical removal of the pituitary lesion within the posterior lobe did not improve hypercortisolism and we continued to treat the patient with metyrapone to block cortisol production. At 18-months follow-up from initial presentation, we detected an ACTH-producing neuroendocrine carcinoma of the mesentery by using a combination of octreotide scan, computed tomography scan, and positron emission tomography. Intraoperatively, use of a gamma probe after administration of radiolabeled (111)In-pentetreotide helped identify the mesenteric neuroendocrine tumor. After removal of this carcinoma, the patient improved clinically. Laboratory testing confirmed remission of hypercortisolism. An octreotide scan 7 months after surgery showed normal results. CONCLUSION: This case underscores the diagnostic challenge in identifying an ectopic ACTH-producing tumor and the pluripotency of cells, in this case of mesenteric cells that can start producing and secreting ACTH. It thereby helps elucidate the pathogenesis of neuroendocrine tumors. This case also suggests that patients with ectopic Cushing's syndrome and an octreotide scan positive in atypical locations may benefit from explorative radioguided surgery using (111)In-pentetreotide and a gamma probe

Simplified Volume of Fluid Method (SVOF) for two-phase flows

The PLIC approach has been usually used in recent implementations of the VOF method i.e. the interphasal surface is approximated by a plane with an arbitrary orientation with respect to the computational cell. Although this method is accurate, it is rather difficult to implement, as a large number of orientations need to be taken into account and the calculation of volume fraction fluxes is not straightforward. A simpler approach to VOF – SLIC – requires much less effort from the programmer but the interface approximation by a plane parallel to the cell surfaces is too crude and the results are not satisfactory. The method presented in the article may be considered as an intermediate approach between PLIC and SLIC – fluxes are computed directly only for the interface’s special orientations and linear interpolation is used for calculation of the fluxes for the remaining cases. Some classical tests of the proposed method are performed and an example of a broken dam problem simulation is presented

Volume of Fluid (VOF) type advection methods in two-phase flow: A comparative study (vol 97, pg 52, 2014)

WOS:000403121400014International audienceno abstrac

A consistent momentum transport in CLSVOF method: validation on jet atomization

International audienceMany atomization processes are characterized by large density ratios coupled with large shear. Numerical simulations are known for becoming unstable in these physical conditions. We developed a new mass and momentum consistent algorithm for CLSVOF method. Based on Rudman's work, the originality of our approach is to avoid using a sub-grid by splitting flux calculation between neighboring cells. The method is validated by comparing simulations with theoretical results and experimental air assisted atomization of a coaxial jet

A consistent momentum transport in CLSVOF method: validation on jet atomization

International audienceMany atomization processes are characterized by large density ratios coupled with large shear. Numerical simulations are known for becoming unstable in these physical conditions. We developed a new mass and momentum consistent algorithm for CLSVOF method. Based on Rudman's work, the originality of our approach is to avoid using a sub-grid by splitting flux calculation between neighboring cells. The method is validated by comparing simulations with theoretical results and experimental air assisted atomization of a coaxial jet