急性期虚血性脳卒中患者から機械的血栓回収術で得られた血栓の年齢と組成は血栓回収術転帰および臨床転帰と関連していた

Introduction: Understanding the composition of stroke thrombi retrieved by mechanical thrombectomy is essential to clarify the pathogenesis of stroke. However, it is difficult to evaluate thrombus composition precisely and objectively. Immunohistochemical staining was used to evaluate thrombus composition and age. Materials and methods: Consecutive thrombi (n = 108) retrieved from patients who underwent mechanical thrombectomy for acute large-vessel ischemic stroke were retrospectively analyzed. Lytic features of granulocytes and CD163 were estimated as indicators of the age of the cardioembolic (CE) thrombus. Results: The stroke subtypes were as follows: CE, 74 cases; large artery atherosclerosis, 11; undetermined etiology, 12; and other determined etiology, 11. There were no statistical differences in thrombi composition according to stroke subtypes. The fibrin area was positively correlated with the red blood cell (RBC) and platelet areas. The following analysis was performed using CE only. Regarding age, the thrombus was judged as fresh in 30.0 % and older in 70.0 % based on the lytic features. The RBC areas of older thrombi were smaller than those of fresh thrombi. The puncture-to-reperfusion time of older thrombi was longer than that of fresh thrombi. Platelet-rich thrombi were associated with a greater number of maneuvers, a smaller prevalence of TICI 3, and unfavorable functional outcomes compared to platelet-poor thrombi. The number of CD163 positive cells in thrombi with anticoagulants was higher than in those without anticoagulants. Conclusion: Thrombus composition correlated with revascularization and clinical outcomes. The composition of an acute ischemic thrombus may reflect the pathophysiology of stroke and influence treatment efficacy.博士（医学）・甲第855号・令和4年12月22日Copyright © 2022 Elsevier Ltd. All rights reserved

Simulation of heat transport in low-dimensional oscillator lattices

The study of heat transport in low-dimensional oscillator lattices presents a formidable challenge. Theoretical efforts have been made trying to reveal the underlying mechanism of diversified heat transport behaviors. In lack of a unified rigorous treatment, approximate theories often may embody controversial predictions. It is therefore of ultimate importance that one can rely on numerical simulations in the investigation of heat transfer processes in low-dimensional lattices. The simulation of heat transport using the non-equilibrium heat bath method and the Green-Kubo method will be introduced. It is found that one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) momentum-conserving nonlinear lattices display power-law divergent, logarithmic divergent and constant thermal conductivities, respectively. Next, a novel diffusion method is also introduced. The heat diffusion theory connects the energy diffusion and heat conduction in a straightforward manner. This enables one to use the diffusion method to investigate the objective of heat transport. In addition, it contains fundamental information about the heat transport process which cannot readily be gathered otherwise.Comment: Article published in: Thermal transport in low dimensions: From statistical physics to nanoscale heat transfer, S. Lepri, ed. Lecture Notes in Physics, vol. 921, pp. 239 - 274, Springer-Verlag, Berlin, Heidelberg, New York (2016

散亂媒質中の粒子の擴散 : 偶然累加量の確率分布

A general method is discussed for the treatment of the probability distribution functions of randomly additive quantities which are related to a certain Markoffian process. It is shown that the generating function method making use of the Laplace transformation gives a systematic way of treatment. Then the main problem is reduced to a certain Eigen-value problem, which has been proved very useful for some statistical-thermodynamical problems and some diffusion problems in physics. The slowing down of neutrons in a scattering medium is discussed from the point of view, which is an interesting example of the stochastic problems. Though the results are almost the same as those described in Marshak's paper (Rev. Mod. Phys. 19, 185 (1947)), the discussions will throw light into the nature of the problem