[Indocyanine green in delayed esophageal reconstruction after previous extirpation]. / Primenenie indotsianina zelenogo pri otsrochennoi plastike pishchevoda tolstoi kishkoi posle ego ekstirpatsii.

Advanced chemo- and radiotherapy makes it possible to expand the cohort of patients who can undergo surgical treatment for esophageal cancer. Optimization of perioperative approach, diagnosis and modern options for complications reduced early postoperative mortality after esophagectomy. Conduit ischemia with failure of esophageal-gastric or esophageal-intestinal anastomosis is one of the most serious complications. To minimize the risk of anastomotic leakage and graft necrosis in these patients, various methods of intraoperative assessment of graft viability are being investigated. Near-infrared fluorescence imaging with indocyanine green is valuable for real time assessment of graft perfusion. To date, fluorescence imaging is analyzed regarding perfusion of the gastric stalk after esophagectomy. However, there are still few or no data on this method for analysis of colonic conduit perfusion. The absence of plastic material for gastrointestinal reconstruction is the most dangerous moment in case of ischemia and necrosis of colonic graft. We present our first case of delayed retrosternal esophageal repair using intraoperative indocyanine green fluorescence imaging for assessment of conduit perfusion.

Thermodynamic approach for the understanding of the kinetics of heat effects induced by structural relaxation of metallic glasses.

We present a novel approach to the understanding of heat effects induced by structural relaxation of metallic glasses. The key idea consists in the application of a general thermodynamic equation for the entropy change due to the evolution of a non-equilibrium part of a complex system. This non-equilibrium part is considered as a defect subsystem of glass and its evolution is governed by local thermoactivated rearrangements with a Gibbs free energy barrier proportional to the high-frequency shear modulus. The only assumption on the nature of the defects is that they should provide a reduction of the shear modulus-a diaelastic effect. This approach allows to determine glass entropy change upon relaxation. On this basis, the kinetics of the heat effects controlled by defect-induced structural relaxation is calculated. A very good agreement between the calculation and specially performed calorimetric and shear modulus measurements on three metallic glasses is found.

Determination of the thermodynamic potentials of metallic glasses and their relation to the defect structure.

We performed calorimetric and shear modulus measurements on four bulk metallic glasses upon heating up to the temperature of the complete crystallization as well as in the fully crystallized state. On the basis of calorimetric experiments, we calculated the excess thermodynamic potentials with respect to the crystalline state-the enthalpy ΔH, entropy ΔSand Gibbs free energy ΔΦ-as functions of temperature. Using high-frequency shear modulus measurements we show that calorimetric determination of ΔH, ΔSand ΔΦ is consistent with the calculation of these potentials within the framework of the interstitialcy theory (IT) within a 15% uncertainty in the worst case for all MGs under investigation. It is concluded that the physical origin of the excess thermodynamic potentials in MGs can be related to a system of interstitial-type defects frozen-in from the liquid state upon melt quenching as suggested by the IT. The estimates of the defect formation enthalpyHfand entropySfshow thatHfscales with the shear modulus whileSfis quite large (10kBto 20kB), in line with the basic assumptions of the IT.

On the nature of the shear viscosity and shear modulus relaxation in metallic glasses.

Analysis of independent isothermal and linear heating creep and shear modulus measurements performed on bulk Pd- and Zr-based metallic glasses provides evidence that the relaxation of their viscoelastic and elastic properties is controlled by 'defects', which respond to stress and temperature similarly to dumbbell interstitials in simple crystalline metals.