Aims: Smaller low-density lipoprotein (LDL) particle size has been suggested to result in the development of endothelial dysfunction, atherosclerosis, and in-stent restenosis (ISR); however, little ...is known regarding the impact of the LDL particle size on the neointima formation leading to ISR after everolimus-eluting stent (EES) implantation. Methods: In this study, we have included 100 patients to examine the relationship between an LDL-C/apolipoprotein B (Apo B) ≤ 1.2, reportedly representing the LDL particle size, and the neointimal characteristics using optical coherence tomography (OCT) and coronary angioscopy (CAS) during the follow-up coronary angiography (CAG) period (8.8±2.5 months) after EES implantation. We divided them into two groups: LDL-C/Apo B ≤ 1.2 group (low LDL-C/Apo B group, n=53) and LDL-C/Apo B ＞1.2 group (high LDL-C/Apo B group, n=47). Results: The low LDL-C/Apo B group had a significantly larger neointimal volume (12.8±5.3 vs. 10.3±4.9 mm3, p=0.021) and lower incidence of a neointimal homogeneous pattern (71 vs. 89 %), higher incidence of a neointimal heterogeneous pattern (25 vs. 9 %) (p=0.006) and higher prevalence of macrophage accumulation (9 vs. 2 %) (p=0.030) as assessed via OCT, and, as per the CAS findings, a higher prevalence of yellow grade ≥ 2 (grade 2; adjusted residual: 2.94, grade 3; adjusted residual: 2.00, p=0.017) than the high LDL-C/Apo B group. Conclusions: A low LDL-C/Apo B ratio was found to be strongly associated with neointimal proliferation and neointimal instability evidenced chronically by OCT and CAS. An LDL-C/Apo B ≤ 1.2 will be of aid in terms of identifying high-risk patients after EES implantation.
Aims: Wall shear stress (WSS) has been considered a major determinant of aortic atherosclerosis. Recently, non-obstructive general angioscopy (NOGA) was developed to visualize various atherosclerotic ...pathologies, including in vivo ruptured plaque (RP) in the aorta. However, the relationship between aortic RP and WSS distribution within the aortic wall is unclear. This study aimed to investigate the relationship between aortic NOGA-derived RP and the stereographic distribution of WSS by computational fluid dynamics (CFD) modeling using three-dimensional computed tomography (3D-CT) angiography. Methods: We investigated 45 consecutive patients who underwent 3D-CT before coronary angiography and NOGA during coronary angiography. WSS in the aortic arch was measured by CFD analysis based on the finite element method using uniform inlet and outlet flow conditions. Aortic RP was detected by NOGA. Results: Patients with a distinct RP showed a significantly higher maximum WSS value in the aortic arch than those without aortic RP (56.2±30.6 Pa vs 36.2±19.8 Pa, p=0.017), no significant difference was noted in the mean WSS between those with and without aortic RP. In a multivariate logistic regression analysis, the presence of a maximum WSS value more than a specific value was a significant predictor of aortic RP (odds ratio 7.21, 95% confidence interval 1.78-37.1, p=0.005). Conclusions: Aortic RP detected by NOGA was strongly associated with a higher maximum WSS in the aortic arch derived by CFD using 3D-CT. The maximum WSS value may have an important role in the underlying mechanism of not only aortic atherosclerosis, but also aortic RP.
The reaction of 3,5-di-O-benzyl-2-deoxy-d-ribofuranose with various alkynyllithium reagents afforded diastereomeric mixtures of the corresponding ring-opened alkynyldiols. The resulting ...diastereomeric mixtures were successively treated with Co2(CO)8, a catalytic amount of TfOH, Et3N, and iodine in one pot to give alkynyl C-3,5-di-O-benzyl-2-deoxy-β-d-ribofuranosides with high β-selectivities. The cobalt-mediated cyclization (intramolecular Nicholas reaction) is reversible; thus, thermodynamically more stable β-anomers were obtained preferentially. The alkynyl C-deoxyribofuranosides were converted to a variety of C-deoxyribofuranoside derivatives.
This paper describes performance simulations and test results of a prototype to develop a multi-fuel gas engine driven Stirling heat pump. It is mainly driven by engine shaft power and is partially ...assisted by thermal power from the engine exhaust heat source. We have developed the D-3 machine, the fourth generation prototype of the heat-assisted Stirling heat pump. This machine uses helium gas as a working gas and is constructed as a combination of two Stirling sub-systems;one a power producer and one a heat pump. Utilizing both shaft power and thermal power, performance is controlled by phase shifting of the hot-side piston to adjust the absorbing of thermal power. This heat pump produced colling and heating water at high COP over 4 on an indicated basis. Developing this machine will provide a CFC-free thermal utilization system technology that satisfies both wide heat demands and various fuel systems.
We experimentally investigated the radiation heat exchange occurring in a gas-solid fluidized bed between the fluidizing particles and a heated heat transfer surface. To evaluate this heat exchange, ...radiation emitted from fluidizing particles located adjacent to the heated surface was measured using an infrared imager through the transparent MgF2 heated surface, which was remotely heated by a CO2 laser. Our results revealed that the fluidizing particles are indeed heated by the surface. In addition, we found that these particles frequently emit a significant amount of radiation energy against the surface, which suppresses the radiation heat exchange between it and the fluidizing particles, and that the radiation energy increases with decreasing particle diameter and increasing particle emissivity.
We experimentally investigated the radiation heat exchange occurring in a gas–solid fluidized bed (kept at 25
°
C) between the fluidizing particles and a remotely-heated heat transfer surface (30
°
...C). To evaluate this heat exchange, radiation emitted from the fluidizing particles towards the heated surface was measured through a transparent heat transfer surface using an infrared imager. Our experimental results revealed that the fluidizing particles are mainly heated by conduction during the contact period with the surface and/or by gas convection in the thermal boundary layer, and that these heated particles frequently emit a significant amount of radiation energy toward the surface. Based on these results, a method for evaluating the radiation heat exchange between the heat transfer surface and the fluidizing particles is proposed. The proposed method shows that particle diameter is one of the most significant parameters in the radiation heat exchange, and predicts that the radiation heat exchange increases with increasing particle diameter.
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