scholarly journals Sharp Estimates of Radial Dunkl and Heat Kernels in the Complex Case A n

2021 ◽  
Vol 359 (4) ◽  
pp. 427-437
Author(s):  
Piotr Graczyk ◽  
Patrice Sawyer
Keyword(s):  
Heat Kernels ◽  
Complex Case ◽  
Sharp Estimates

Requirement of staged interventions in a complex case of Acromegaly and Obstructive Sleep Apnoea

2020 ◽  
Author(s):  
Mili Dhar ◽  
Jennifer Elias ◽  
Benjamin Field ◽  
Sunil Zachariah ◽  
Julian Emmanuel
Keyword(s):  
Obstructive Sleep Apnoea ◽  
Sleep Apnoea ◽  
Complex Case ◽  
Obstructive Sleep

Sturm-Liouville Problem for Stationary Differential Operator with Nonlocal Two-Point Boundary Conditions

2006 ◽  
Vol 11 (1) ◽  
pp. 47-78 ◽  
Author(s):  
S. Pečiulytė ◽  
A. Štikonas
Keyword(s):  
Boundary Condition ◽  
Differential Operator ◽  
Boundary Conditions ◽  
Nonlocal Boundary Condition ◽  
Nonlocal Boundary ◽  
Liouville Problem ◽  
Complex Case ◽  
Qualitative Behavior ◽  
Point Boundary ◽  
Sturm Liouville

The Sturm-Liouville problem with various types of two-point boundary conditions is considered in this paper. In the first part of the paper, we investigate the Sturm-Liouville problem in three cases of nonlocal two-point boundary conditions. We prove general properties of the eigenfunctions and eigenvalues for such a problem in the complex case. In the second part, we investigate the case of real eigenvalues. It is analyzed how the spectrum of these problems depends on the boundary condition parameters. Qualitative behavior of all eigenvalues subject to the nonlocal boundary condition parameters is described.

Development and evaluation of a patient-specific surgical simulator for endoscopic colloid cyst resection

2020 ◽  
Vol 133 (2) ◽  
pp. 521-529 ◽  
Author(s):  
Vivek P. Bodani ◽  
Gerben E. Breimer ◽  
Faizal A. Haji ◽  
Thomas Looi ◽  
James M. Drake
Keyword(s):  
Choroid Plexus ◽  
Computer Aided Design ◽  
Third Ventricle ◽  
Colloid Cyst ◽  
Comfort Level ◽  
Complex Case ◽  
Patient Specific ◽  
Surgical Simulator ◽  
Perceived Realism ◽  
Noncontrast Ct

OBJECTIVEEndoscopic resection of third-ventricle colloid cysts is technically challenging due to the limited dexterity and visualization provided by neuroendoscopic instruments. Extensive training and experience are required to master the learning curve. To improve the education of neurosurgical trainees in this procedure, a synthetic surgical simulator was developed and its realism, procedural content, and utility as a training instrument were evaluated.METHODSThe simulator was developed based on the neuroimaging (axial noncontrast CT and T1-weighted gadolinium-enhanced MRI) of an 8-year-old patient with a colloid cyst and hydrocephalus. Image segmentation, computer-aided design, rapid prototyping (3D printing), and silicone molding techniques were used to produce models of the skull, brain, ventricles, and colloid cyst. The cyst was filled with a viscous fluid and secured to the roof of the third ventricle. The choroid plexus and intraventricular veins were also included. Twenty-four neurosurgical trainees performed a simulated colloid cyst resection using a 30° angled endoscope, neuroendoscopic instruments, and image guidance. Using a 19-item feedback survey (5-point Likert scales), participants evaluated the simulator across 5 domains: anatomy, instrument handling, procedural content, perceived realism, and confidence and comfort level.RESULTSParticipants found the simulator’s anatomy to be highly realistic (mean 4.34 ± 0.63 [SD]) and appreciated the use of actual instruments (mean 4.38 ± 0.58). The procedural content was also rated highly (mean 4.28 ± 0.77); however, the perceived realism was rated slightly lower (mean 4.08 ± 0.63). Participants reported greater confidence in their ability to perform an endoscopic colloid cyst resection after using the simulator (mean 4.45 ± 0.68). Twenty-three participants (95.8%) indicated that they would use the simulator for additional training. Recommendations were made to develop complex case scenarios for experienced trainees (normal-sized ventricles, choroid plexus adherent to cyst wall, bleeding scenarios) and incorporate advanced instrumentation such as side-cutting aspiration devices.CONCLUSIONSA patient-specific synthetic surgical simulator for training residents and fellows in endoscopic colloid cyst resection was successfully developed. The simulator’s anatomy, instrument handling, and procedural content were found to be realistic. The simulator may serve as a valuable educational tool to learn the critical steps of endoscopic colloid cyst resection, develop a detailed understanding of intraventricular anatomy, and gain proficiency with bimanual neuroendoscopic techniques.

scholarly journals Lower estimates of heat kernels for non-local Dirichlet forms on metric measure spaces

2017 ◽  
Vol 272 (8) ◽  
pp. 3311-3346 ◽  
Author(s):  
Alexander Grigor'yan ◽  
Eryan Hu ◽  
Jiaxin Hu
Keyword(s):  
Dirichlet Forms ◽  
Heat Kernels ◽  
Metric Measure Spaces ◽  
Measure Spaces ◽  
Non Local

scholarly journals THU0590 WHEN RARE IS EVEN RARER: A COMPLEX CASE OF BEHCET DISEASE

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 537.3-537
Author(s):  
M. DI Cicco ◽  
O. M. Epis ◽  
C. Casu ◽  
A. Adinolfi ◽  
L. Alvaro ◽  
...  
Keyword(s):  
Pulmonary Artery ◽  
Vascular Complications ◽  
Artery Aneurysm ◽  
Skin Lesions ◽  
Complex Case ◽  
Behçet Disease ◽  
Inflammatory Disorder ◽  
X Rays ◽  
Behcet Disease ◽  
Intracardiac Thrombosis

Background:Behcet disease is a rare inflammatory disorder with the unique ability to affect vessels of any size. The disease could be associated to thrombosis in both the venous and arterial compartment, and often aneurysms. In particular, the presence of aneurysms of the pulmonary artery is rarely, if ever, seen in conditions other than Behcet. Cardiac involvement, albeit uncommon, is also described and associated to a severe prognosis. The treatment is based on immunosuppressants, meanwhile the use of anticoagulants -especially when aneurysms are present- is debated.Objectives:To describe a complex case of Behcet disease.Methods:We report the case of a 45 years old man of Chinese origin who presented to A&E with fever and acute dyspnea. Blood test revealed raised ESR and CRP and raised neutrophil count. Chest X rays showed bilateral opacities suggesting pneumonia. The patient did not improve over the course of antibiotics. Later on, he presented with an episode of hemoptysis and worsening dyspnea, so he was admitted to the Intensive Care Unit. CT showed bilateral pulmonary thromboembolism and aneurysm of the pulmonary artery. Echocardiogram and cardio-MRI revealed a large, mobile thrombus within the right atrium. Extensive work-up for infections and cancer was unrevealing. ANA, ENA and ANCA antibodies were negative. On the basis of a past medical history of recurrent oral ulcers and papulopustular skin lesions that patient admitted on questioning, a diagnosis of Behcet disease was suspected. In keeping with that, HLA-B51 turned out positive. The patient was promptly started on IV steroid pulses followed by Cyclophosphamide 1 gr IV monthly for six months, then on IV anti-TNF alpha Infliximab. He was also commenced on low molecular weight heparin (LMWH) and subsequently direct factor Xa inhibitor Apixaban.Results:The patient improved significantly with progressive regression of the pulmonary CT changes. He was discharged and able to get back to his daily life activities. After 2 years and a half of treatment, the aneurysm was stable and the intracardiac thrombus completely cleared.Conclusion:This case is of particular interest because of the concomitant presence of two rare vascular complications of Behcet disease-intracardiac thrombosis (<1-2%, less than 100 cases described worldwide) and pulmonary artery aneurysm (1-2%). Prompt introduction of immunosuppressant therapy was associated with a favorable outcome with no recurrence. We could speculate that, to some extent, the concomitant use of anticoagulants may have contributed to the complete resolution of the intracardiac thrombosis.Disclosure of Interests :MARIA DI CICCO: None declared, oscar massimiliano epis Consultant of: yes, Speakers bureau: yes, Cinzia Casu: None declared, Antonella Adinolfi: None declared, Luisa Alvaro: None declared, Valeria Campanella: None declared, Michel Chevallard: None declared, Marina Muscarà: None declared, Mariaeva Romano: None declared, Emanuela Schito: None declared, Nicola Ughi: None declared, Elisa Verduci: None declared, Davide Antonio Filippini: None declared

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