Kinetic formulation and global existence for the Hall-Magneto-hydrodynamics system

This paper deals with the derivation and analysis of the the Hall Magneto-Hydrodynamic equations. We first provide a derivation of this system from a two-fluids Euler-Maxwell system for electrons and ions, through a set of scaling limits. We also propose a kinetic formulation for the Hall-MHD equations which contains as fluid closure different variants of the Hall-MHD model. Then, we prove the existence of global weak solutions for the incompressible viscous resistive Hall-MHD model. We use the particular structure of the Hall term which has zero contribution to the energy identity. Finally, we discuss particular solutions in the form of axisymmetric purely swirling magnetic fields and propose some regularization of the Hall equation

Global existence and temporal decay for the 3D compressible Hall-magnetohydrodynamic system

In this paper, we are concerned with the 3D compressible Hall-magnetohydrodynamic system in the whole space. We prove the global existence and temporal decay rates of the solutions to the system when the initial data are close to a stable equilibrium state by using a pure energy method

Characterization of HER2-low breast cancer in young women with germline BRCA1/2 pathogenetic variants: Results of a large international retrospective cohort study

Background: Breast cancer (BC) in women aged ≤40 years carrying germline pathogenetic variants (PVs) in BRCA1/2 genes is infrequent but often associated with aggressive features. Human epidermal growth factor receptor 2 (HER2)-low-expressing BC has recently emerged as a novel therapeutic target but has not been characterized in this rare patient subset. Methods: Women aged ≤40 years with newly diagnosed early-stage HER2-negative BC (HER2-0 and HER2-low) and germline BRCA1/2 PVs from 78 health care centers worldwide were retrospectively included. Chi-square test and Student t-test were used to describe variable distribution between HER2-0 and HER2-low. Associations with HER2-low status were assessed with logistic regression. Kaplan–Meier method and Cox regression analysis were used to assess disease-free survival (DFS) and overall survival. Statistical significance was considered for p ≤.05. Results: Of 3547 included patients, 32.3% had HER2-low BC, representing 46.3% of hormone receptor–positive and 21.3% of triple-negative (TN) tumors. HER2-low vs. HER2-0 BC were more often of grade 1/2 (p <.001), hormone receptor–positive (p <.001), and node-positive (p =.003). BRCA2 PVs were more often associated with HER2-low than BRCA1 PVs (p <.001). HER2-low versus HER2-0 showed better DFS (hazard ratio [HR], 0.86; 95% CI, 0.76–0.97) in the overall population and more favorable DFS (HR, 0.78; 95% CI, 0.64–0.95) and overall survival (HR, 0.65; 95% CI, 0.46–0.93) in the TN subgroup. Luminal A–like tumors in HER2-low (p =.014) and TN and luminal A-like in HER2-0 (p =.019) showed the worst DFS. Conclusions: In young patients with HER2-negative BC and germline BRCA1/2 PVs, HER2-low disease was less frequent than expected and more frequently linked to BRCA2 PVs and associated with luminal-like disease. HER2-low status was associated with a modestly improved prognosis

Analgesia postoperatoria en pacientes sometidos a anestesia regional intravenosa con tramadol

Inspirada en el problema que representa para m\ue9dicos y pacientes cl dolor postoperatorio, el cual en la mayor\ueda de casos es tratado inadecuadamente y en alg\ufan porcentaje, simplemente no es tratado, todo lo que resulta en un padecimiento mas que se agrega al de cada paciente, se decidi\uf3 realizar el presente estudio Experimental tipo Ensayo Cl\uednico Controlado Simple Ciego, en pacientes adultos ASA I, II y III, en edades comprendidas entre 18 y 60 a\uf1os, con patolog\ueda quir\ufargica Traumato1\uf3gica de Miembro Superior que permitiera su resoluci\uf3n mediante el uso de la Anestesia Regional Intravenosa, durante cl periodo Julio 2000 - Noviembre 2001, con recursos propios. La muestra fu\ue9 seleccionada y dividida al azar en 2 grupos de 15 personas cada uno. Al primer grupo se le administr\uf3 Lidocaina al 2% en dosis de 3 mg/Kg de peso aumentando su volumen hasta obtener 40 mI, con Soluci\uf3n Fisiol\uf3gica al 0,9%. Al Segundo grupo, se le administr\uf3 Lidocaina al 2% en igual dosis + Tramadol en dosis de 100 mg ( 2 ml ), aumentando su volumen a 40 mI con Soluci\uf3n Fisio1\uf3gica, al 0,9%. Los criterios de exclusi\uf3n fueron: pacientes Hipertensos, Diab\ue9ticos, con Patolog\ueda Vascular; pacientes que se negaran a recibir \ue9ste tipo de Anestesia, tiempo quir\ufargico mayor a 60 minutos y pacientes con Fen\uf3meno de Raynaud. La Mediana de aparici\uf3n del dolor fu\ue9 mayor en el grupo que recibi\uf3 Lidocaina + Tramadol con diferencia estad\uedsticamente significativa (p=3D0,0003); concluy\ue9ndose que la administraci\uf3n de Tramadol en Anestesia Regional Intravenosa es efectiva porque prolonga la aparici\uf3n del dolor postoperatorio, tiene pocos efectos colaterales, por lo que se recomienda su uso

Singularity formation for the incompressible Hall-MHD equations without resistivity

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