39 research outputs found

    Linear Koszul duality and Fourier transform for convolution algebras

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    In this paper we prove that the linear Koszul duality isomorphism for convolution algebras in K-homology defined in a previous paper and the Fourier transform isomorphism for convolution algebras in Borel-Moore homology are related by the Chern character. So, Koszul duality appears as a categorical upgrade of Fourier transform of constructible sheaves. This result explains the connection between the categorification of the Iwahori-Matsumoto involution for graded affine Hecke algebras (due to Evens and the first author) and for usual affine Hecke algebras (obtained in a previous paper).Comment: v1: 29 pages; v2: 41 pages, many details added; v3: 42 pages, minor modifications (final version, to appear in Doc. Math.

    LINEAR KOSZUL DUALITY AND AFFINE HECKE ALGEBRAS

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    n this paper we prove that the linear Koszul duality equivalence constructed in a previous paper provides a geometric realization of the Iwahori-Matsumoto involution of affine Hecke algebras

    First measured intrathoracic blood volume in icu patients indicates the appropriateness of circulatory volume management

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    Hemodynamic monitoring in Intensive Care Unit (ICU) settings is usually introduced when a patient becomes hemodynamically unstable. We analyzed how empirically guided volume management relates to first measured intrathoracic blood volume (ITBV), at the moment of the beginning of Puls Contour Cardiac Output (PiCCO) hemodynamic monitoring. Data and measurements from 37 ICU patients, divided into four groups according to diagnosis of primary condition, were retrospectively studied. The first group consisted of polytrauma patients, second group of patients with pancreatitis and/or peritonitis, third group were postoperative patients, and fourth group were patients with various medical diagnosis: sepsis, acute respiratory distress syndrome (ARDS), acute lung failure (ALF), and acute heart failure (AHF). PiCCO monitor was introduced when the signs of hemodynamic instability were observed. First measured ITBV was recorded and analyzed according to deviation from reference values. First measured ITBV was in reference range in 14 (37.8%) patients. Volume overloading was observed in 16 (43.2%) and hypovolemia in 7 (18.9%) patients. The observed inappropriate blood volume in patients of all studied groups suggests that there is the need for defining indications and earlier application of hemodynamic monitoring, as well as reassessment of usual empirically guided infusion therapy in ICU setting

    First measured intrathoracic blood volume in icu patients indicates the appropriateness of circulatory volume management

    Get PDF
    Hemodynamic monitoring in Intensive Care Unit (ICU) settings is usually introduced when a patient becomes hemodynamically unstable. We analyzed how empirically guided volume management relates to first measured intrathoracic blood volume (ITBV), at the moment of the beginning of Puls Contour Cardiac Output (PiCCO) hemodynamic monitoring. Data and measurements from 37 ICU patients, divided into four groups according to diagnosis of primary condition, were retrospectively studied. The first group consisted of polytrauma patients, second group of patients with pancreatitis and/or peritonitis, third group were postoperative patients, and fourth group were patients with various medical diagnosis: sepsis, acute respiratory distress syndrome (ARDS), acute lung failure (ALF), and acute heart failure (AHF). PiCCO monitor was introduced when the signs of hemodynamic instability were observed. First measured ITBV was recorded and analyzed according to deviation from reference values. First measured ITBV was in reference range in 14 (37.8%) patients. Volume overloading was observed in 16 (43.2%) and hypovolemia in 7 (18.9%) patients. The observed inappropriate blood volume in patients of all studied groups suggests that there is the need for defining indications and earlier application of hemodynamic monitoring, as well as reassessment of usual empirically guided infusion therapy in ICU setting

    Frequency dependent effect of selective biphasic left vagus nerve stimulation on heart rate and arterial pressure

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    Activation of the parasympathetic pathway leads to negative chronotropic, dromotropic, and inotropic changes of heart function. The ability to selectively stimulate certain superficial compartments of peripheral nerves has been demonstrated previously. The aim of the present study was to find a clinically acceptable selective biphasic vagus nerve stimulation technique, which could allow gradual regulation of heart rate and systemic arterial pressure. In two patients, the left vagus nerve was stimulated with a combination of quasi-trapezoidal cathodic and rectangular anodic current pulses with different stimulation frequencies (10Hz, 20Hz, 30Hz) and increasing current. The heart rate and systemic arterial pressure decreased with increasing current at all different stimulation frequencies (p<0.05). The heart rate and arterial pressure response was more gradual with 10Hz compared to 20Hz/30Hz vagus nerve stimulation (p<0.05). In conclusion, selective vagus nerve stimulation, with a combination of quasi-trapezoidal cathodic and rectangular anodic current pulses at 10Hz, offers gradual heart rate and systolic arterial pressure control
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