Development of Hybrid Safety Systems for Next-Generation PWR Makihara, Yoshiaki; Sugizaki, Takayoshi; Okabe, Kazuharu ...
Transactions of the Japan Society of Mechanical Engineers Series B,
1993/09/25, Letnik:
59, Številka:
565
Journal Article
Odprti dostop
Design requirements for the next-generation LWR have been investigated by many organization. In summary, these investigations suggest that improvement in plant safety is required through the ...evaluation of system simplification, reliability enhancement and preclusion of human factors. Hybrid safety systems, which are combinations of passive safety systems and active safety systems, have the possibility to satisfy the design requirements for next-generation LWR. This article shows the configuration of hybrid safety systems by describing the system selection process and then shows the results of system simplification.
Design requirements for the next-generation LWR have been investigated by many organization. In summary, these investigations suggest that improvement in plant safety is required through the ...evaluation of system simplification, reliability enhancement and preclusion of human factors. Hybrid safety systems, which are combinations of passive safety systems and active safety systems, have the possibility to satisfy the design requirements for next-generation LWR. This article shows the configuration of hybrid safety systems by describing the system selection process and then shows the results of system simplification.
Background:In-stent neoatherosclerosis (NA) is a risk for future cardiovascular events through atherosclerotic progression in non-stented lesions. Using optical coherence tomography, this study ...assessed the efficacy of intensive therapy with 10 mg/day rosuvastatin plus 1,800 mg/day eicosapentaenoic acid (EPA) vs. standard 2.5 mg/day rosuvastatin therapy on native coronary plaques in patients with NA.Methods and Results:This was a subgroup analysis of the randomized LINK-IT trial, which was designed to compare changes in the lipid index in NA between intensive and standard therapy for 12 months. In all, 42 patients with native coronary plaques and NA were assessed. Compared with standard therapy, intensive therapy resulted in greater decreases in serum low-density lipoprotein cholesterol concentrations and greater increases in serum 18-hydroxyeicosapentaenoic acid concentrations, with significantly greater decreases in the lipid index and macrophage grade in both NA (−24 vs. 217 P<0.001 and −15 vs. 24 P<0.001, respectively) and native coronary plaques (−112 vs. 29 P<0.001 and −17 vs. 1 P<0.001, respectively) following intensive therapy. Although there was a greater increase in the macrophage grade in NA than in native coronary plaques in the standard therapy group, in the intensive therapy group there were comparable reductions in macrophage grade between NA and native coronary plaques.Conclusions:Compared with standard therapy, intensive therapy prevented atherosclerotic progression more effectively in native coronary plaques in patients with NA.
Whether predicting the rotational atherectomy (RA) effect based on the position of optical frequency domain imaging (OFDI) is accurate remains uncertain. The aim of this study was to evaluate the ...predictive accuracy of OFDI in identifying RA location and area. Twenty-five patients who underwent RA with OFDI were included. On pre-RA OFDI images, a circle with the dimension of a Rota burr was drawn at the center of the OFDI catheter. The area where the circle overlapped with the vessel wall was defined as the predicted ablation area (P-area), and the actual ablated area (A-area) was measured. The predictive accuracy of OFDI was evaluated as follows: overlapped ablation area (O-area: overlapping P- and A-areas) divided by P-area = %Correct-area, and A-area − O-area divided by A-area = %Error-area. Cross-sections were separated into four categories based on the median values of %Correct- and %Error-area. Among 334 cross-sections, RA effects were confirmed in the predicted location in 87% of them. The median %Correct- and %Error-areas were 43.1% and 64.2%, respectively. Floppy wire, narrow lumen area, OFDI catheter close to the intima, and large arc of calcium were independently associated with good prediction (high %Correct-/low %Error-areas). Non-left anterior descending lesions, OFDI catheter far from the wire, and OFDI catheter and wire far from the intima were associated with irrelevant ablation (low %Correct-/ high %Error-areas). The accuracy of the OFDI-based predictions for RA effects was acceptable with regard to location, but not high with regard to area. Wire types, target vessels, and OFDI catheter and wire positions are important determinants for accurately predicting RA effect using pre-procedural OFDI.
The initial process of atherosclerotic development has not been systematically evaluated. This study aimed to observe atherosclerotic progression from normal vessel wall (NVW) to atherosclerotic ...plaque and examine local factors associated with such progression using > 5-year long-term follow-up data obtained by serial optical coherence tomography (OCT). A total of 49 patients who underwent serial OCT for lesions with NVW over 5 years (average: 6.9 years) were enrolled. NVW was defined as a vessel wall with an OCT-detectable three-layer structure and intimal thickness ≤ 300 μm. Baseline and follow-up OCT images were matched, and OCT cross sections with NVW > 30° were enrolled. Cross sections were diagnosed as “progression” when the NVW in these cross sections was reduced by > 30° at > 5-year follow-up. Atherogenic progression from NVW to atherosclerotic plaque was observed in 40.8% of enrolled cross sections. The incidence of microchannels in an adjacent atherosclerotic plaque within the same cross section (6.7 vs. 3.3%;
p
= 0.046) and eccentric distribution of atherosclerotic plaque (25.0 vs. 12.6%;
p
< 0.001) at baseline was significantly higher in cross sections with progression than in those without. Cross sections with progression exhibited significantly higher NVW intimal thickness at baseline than cross sections without progression (200.1 ± 53.7 vs. 180.2 ± 59.6 μm;
p
< 0.001). Multivariate analysis revealed that the presence of microchannels in an adjacent atherosclerotic plaque, eccentric distribution of atherosclerotic plaque, and greater NVW intimal thickness at baseline were independently associated with progression at follow-up. The presence of microchannels in an adjacent atherosclerotic plaque, eccentric distribution of atherosclerotic plaque, and greater NVW intimal thickness were potentially associated with initial atherosclerotic development from NVW to atherosclerotic plaque.
Culprit lesions of acute coronary syndrome (ACS) could be classified as plaque rupture (PR), erosion, or calcified nodule (CN). We aimed to determine the relationship among clinical characteristics, ...morphological plaque features, and long-term prognosis in ACS. Patients with ACS, who underwent pre-intervention optical coherence tomography between April 2013 and July 2018 were retrospectively enrolled, and classified into the three groups based on the culprit lesion morphology. In the 436 patients enrolled, incidences of PR, erosion, and CN in ACS culprit lesions were 46.1, 39.9, and 14.0%, respectively. Plaque erosion was more frequent in men aged < 60 years and CN was more frequent in older adults in both sexes (≥ 80 years) (P < 0.001). Patients with CN had a higher incidence of hemodialysis treatment (P < 0.001) and diabetes (P = 0.003). Multivariate analysis revealed that ST elevation myocardial infarction (STEMI) (P = 0.049) and presence of thin-cap fibroatheroma (TCFA) at the culprit lesion were independently associated with PR; in younger patients (< 60 year), preserved left ventricular ejection fraction and lower incidence of TCFA were correlated with plaque erosion; and older age, non-STEMI, or unstable angina pectoris, higher serum brain natriuretic peptide levels, and lower incidence of TCFA were independently associated with CN. Multivariable analysis revealed that CN (odds ratio OR 1.990, P = 0.005), male sex (OR 2.012, P = 0.004), and older age (OR 1.036, P < 0.001) were independently associated with future adverse events during a median follow-up of 757 days. Different patient characteristics and morphological features were associated with the type of culprit lesion in patients with ACS.
In this paper, we investigate the deployment properties of step-index multi-core fibers (SI-MCFs) and trench-assisted multi-core fibers (TA-MCFs) in terrestrial high-density cables and links. We ...reveal that SI-MCFs and TA-MCFs can be designed with the same core pitch while maintaining their compatibility with conventional single-mode fiber (SMF) compliant with ITU-T Recommendation G.652. When SI-MCFs and TA-MCFs were implemented in high-density cables, we observed no significant increase in loss during the cabling and installation processes. Furthermore, the crosstalk deviation between processes is consistent with power coupling theory, indicating that effective bending is a key factor in determining the crosstalk under deployed conditions. We also confirm that good fusion splicing for MCF link connection is achievable by ensuring sufficient angular alignment accuracy. Additionally, our field experiments verify that accounting for the randomness of MCFs in the longitudinal direction of the link can reduce the characteristic deviation between MCF cores, leading to improved transmission characteristics.
•ALTAIR: Phase IV, open-label, randomized, parallel-group, single-center study.•Alirocumab arm: alirocumab 75mg every 2 weeks added to rosuvastatin 10mg/day.•Standard-of-care arm: rosuvastatin ...10mg/day.•Optical coherence tomography (OCT) imaging at baseline and at week 36 (post-treatment).•Main outcome measure: change in thickness of the fibrous cap (blinded OCT analysis).
Although a recent clinical trial demonstrated that alirocumab, a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, significantly reduces the incidence of acute coronary events, the impact of alirocumab on plaque stabilization remains uncertain. The Efficacy of ALirocumab for Thin-cap fibroatheroma in patients with coronary Artery disease estImated by optical coherence tomogRaphy (ALTAIR) study will investigate the effect of alirocumab on thin-cap fibroatheroma (TCFA) in Japanese patients who underwent recent percutaneous coronary intervention (PCI).
ALTAIR is a phase IV, open-label, randomized, parallel-group, single-center study involving blinded optical coherence tomography (OCT) image analysis in Japanese adults hospitalized for PCI and having suboptimal control of low-density lipoprotein cholesterol (LDL-C) levels (>70mg/dL) despite statin therapy. Patients will be randomized (1:1) to the alirocumab arm (alirocumab 75mg every 2 weeks added to rosuvastatin 10mg/day) or the standard-of-care arm (rosuvastatin 10mg/day, with initiation and/or dose adjustment of non-statin lipid-lowering to achieve an LDL-C target of <70mg/dL). OCT imaging will be conducted at baseline and at week 36 (post-treatment). The primary objective is to compare the alirocumab and standard-of-care arms regarding the change in TCFA fibrous-cap thickness after 9 months of treatment.
The outcomes of ALTAIR (ClinicalTrials.gov identifier: NCT03552432) will provide insights into the effect of alirocumab on plaque vulnerability following PCI in patients with suboptimal LDL-C control despite stable statin therapy.
PDF
