Usefulness of Clinical Frailty Scale for Comprehensive Geriatric Assessment of Older Heart Failure Patients

Background: Comprehensive geriatric assessment (CGA) is a multidisciplinary diagnostic process to identify the physical, psychological, and social functions of patients with frailty. The Clinical Frailty Scale (CFS) might aid in effectively identifying older patients with heart failure (HF) and frailty who would then reap maximum benefits from the CGA. Methods and Results: A single-centre prospective cohort study that enrolled consecutive hospitalised patients (age ≥75 years) with HF was conducted. The Barthel index (BI), Mini Mental State Examination (MMSE), the Charlson comorbidity index (CCI), and the COntrolling NUTritional (CONUT) for CGA was used. Among 190 enrolled patients (mean age, 85.4 years; 47.9% male), all-cause mortality (primary endpoint) occurred in 45 patients and HF-related rehospitalization (secondary endpoint) in 59 patients within 1 year. The cumulative incidence of all-cause mortality was significantly higher in the high CFS group (low 6.3%, high 30.5%, P<0.001). However, the cumulative incidence of HF-related rehospitalization was not significantly different (low 26.3%, high 32.0%, P=0.304). The multivariable analysis revealed that the CFS group was independently associated with the risk of all-cause mortality. CFS showed a strong correlation with the BI and moderate correlation with the MMSE. Conclusions: The CFS was associated with all-cause mortality within 1 year and was correlated with frailty domains of CGA.

Plant size, latitude, and phylogeny explain within-population variability in herbivory

Interactions between plants and herbivores are central in most ecosystems, but their strength is highly variable. The amount of variability within a system is thought to influence most aspects of plant-herbivore biology, from ecological stability to plant defense evolution. Our understanding of what influences variability, however, is limited by sparse data. We collected standardized surveys of herbivory for 503 plant species at 790 sites across 116° of latitude. With these data, we show that within-population variability in herbivory increases with latitude, decreases with plant size, and is phylogenetically structured. Differences in the magnitude of variability are thus central to how plant-herbivore biology varies across macroscale gradients. We argue that increased focus on interaction variability will advance understanding of patterns of life on Earth.

Phase II Clinical Trial of Hypofractionated Image-Guided Proton Therapy with 12 Fractions for Prostate Cancer

PURPOSE/OBJECTIVE(S)

Towards hypofractionated proton therapy for prostate cancer for improving convenience for patients to receive treatment and improving therapeutic efficacy, image-guided technique with hydrogel spacer solved the late gastrointestinal toxicity, but it is unclear whether acute genitourinary (GU) toxicity is acceptable. The aim of this phase II study was to evaluate the safety and efficacy of hypofractionated image-guided proton therapy (IGPT) with 12 fractions for prostate cancer.

MATERIALS/METHODS

Eligibility criteria were as follows: (1) histologically confirmed primary prostate cancer; (2) T1-T3bN0M0 staged by (UICC TNM8th); (3) ECOG-PS ≤ 2; (4) age ≥ 20 years; (5) no serious underlying disease or other cancers; (6) technically capable of proton therapy, and (7) written informed consent. Primary endpoint was the ratio of grade 2 or more acute genitourinary toxicity. We used the modified CTCAE grading of grade 2 GU toxicities, in which prescribing two and more types of drugs for dysuria within 3 months of the start of radiation was considered to indicate grade 2 GU toxicity. A phase II trial was planned based on the minimax Simon's two-stage design with a significance level of 0.05 and a power of 90%. The acceptable incidence is considered to be less than 5%, and the unacceptable incidence is considered to be more than 15%. A total of 83 patients is required for completion of the trial (7 patients or fewer). After evaluating the primary endpoint in 83 patients, 217 additional patients were registered and a total of 300 patients were registered in order to further examine the safety and efficacy. The prescribed dose to the isocenter was 51.6 GyRBE in 12 fractions (4 days a week).

RESULTS

From January 2020 to March 2021, 30, 53, and 217 patients (total 300) were enrolled. The patient characteristics were as follows: median age, 70 (48-83) years; low/intermediate/high risk, 44/132/124. Forty-nine and 38 patients had benign prostatic hyperplasia and diabetes mellitus, respectively. Grade 2 acute GU toxicities were observed in 1, 5 and 13 patients, respectively (total 6.3%). No grade 3 or higher acute GU toxicities were observed. However, urinary retention during IGPT, which was not previously observed, was observed in 3 cases, and temporary urethral catheterization was performed (Grade 2). Most of the acute GU toxicity tended to improve at 1 month after IGPT, and almost improved at 3 months. Mean score deteriorations beyond the minimum clinically important difference threshold (1/2 SD) were observed only at 1 month in the following scales: summary (-6.0), bother (-7.0), and irritative/obstructive (-6.3).

CONCLUSION

Hypofractionated IGPT with 12 fractions for prostate cancer is well tolerated in acute GU toxicities. Longer follow-up is necessary to evaluate the efficacy and late toxicities. Further investigation of hypofractionated IGPT with 12 fractions for prostate cancer is warranted. Since April 2021, an additional 1000 cases of prospective registration study have been conducted.

Quality of Palliative Radiation Therapy Assessed Using Quality Indicators: A Multicenter Survey

PURPOSE/OBJECTIVE(S)

Clinical practice is not always performed in accordance with guideline recommendations. Quality indicators (QIs) are valuable tools for evaluating the quality of healthcare systems. We sought to identify potential gaps between clinical practice and evidence using QIs previously developed using a modified Delphi method.

MATERIALS/METHODS

We used seven QIs (Table 1) to assess the quality of radiation therapy for bone (BoM) and brain metastases (BrM) at 29 centers; 13 (45%) were academic (12 university hospitals and 1 cancer center) and 16 (55%) were nonacademic hospitals. Compliance rate was calculated as the percentage of patients for whom recommended medical care was conducted. Random effects models were used to estimate pooled compliance rates. Mixed effects models with a Q test were used to compare compliance rates between academic and nonacademic centers.

RESULTS

The estimates of the compliance rates with 95% confidence intervals are presented in Table 1. For BoM-1, the compliance rate was higher in academic hospitals (100% [100-100%]) than in non-academic hospitals (96% [89-100%]) (P = 0.021). For BrM-3, the compliance rate was lower in academic hospitals (92% [81-99%]) than in nonacademic hospitals (100% [98-100%]) (P = 0.016).

CONCLUSION

A quality assessment based on these seven QIs is feasible. Overall, compliance rates were high; however, for BoM-3, the practice remains to be improved in some centers. Based on BoM-4 compliance rates, steroids are infrequently used concurrently with radiation therapy for malignant spinal cord compression. Extended fractionation for BoM was less frequently performed in academic than in nonacademic centers. The initiation of radiation therapy for brain metastases was more frequently delayed in academic than in nonacademic centers.

Extreme phonon anharmonicity underpins superionic diffusion and ultralow thermal conductivity in argyrodite Ag8SnSe6

Ultralow thermal conductivity and fast ionic diffusion endow superionic materials with excellent performance both as thermoelectric converters and as solid-state electrolytes. Yet the correlation and interdependence between these two features remain unclear owing to a limited understanding of their complex atomic dynamics. Here we investigate ionic diffusion and lattice dynamics in argyrodite Ag8SnSe6 using synchrotron X-ray and neutron scattering techniques along with machine-learned molecular dynamics. We identify a critical interplay of the vibrational dynamics of mobile Ag and a host framework that controls the overdamping of low-energy Ag-dominated phonons into a quasi-elastic response, enabling superionicity. Concomitantly, the persistence of long-wavelength transverse acoustic phonons across the superionic transition challenges a proposed 'liquid-like thermal conduction' picture. Rather, a striking thermal broadening of low-energy phonons, starting even below 50 K, reveals extreme phonon anharmonicity and weak bonding as underlying features of the potential energy surface responsible for the ultralow thermal conductivity (<0.5 W m-1 K-1) and fast diffusion. Our results provide fundamental insights into the complex atomic dynamics in superionic materials for energy conversion and storage.

Anomalous behavior of liquid molecules near solid nanoparticles: Novel interpretation on thermal conductivity enhancement in nanofluids

HYPOTHESIS

Recently, it has been reported that anomalous improvement in the thermal conductivity of nanofluid composed of base liquids and dispersed solid nanoparticles, compared to the theoretically predicted value calculated from the particle fraction. Generally, the thermal conductivity values of gases and liquids are dominated by the mean free path of the molecules during translational motion. Herein, we present solid evidence showing the possible contribution of the vibrational behavior of liquid molecules around nanoparticles to increasing these thermal conductivities.

EXPERIMENTS

The behavior of liquid molecules in nanofluids containing SiO₂ particles larger than 100 nm, which were dispersed in a 50 wt% aqueous solution of ethylene glycol, was investigated by means of small-angle neutron scattering, quasi-elastic neutron scattering, wide-angle X-ray scattering, and Raman spectroscopy.

FINDINGS

The vibrational changes in the liquid molecules caused by the interactions between the nanoparticles and liquid molecules surrounding the nanoparticles contributed majorly to the increase in the thermal conductivity values of the SiO₂ nanofluids. Because the vibration of liquid molecules is equivalent to phonon conduction in solids, the increase in thermal conductivity of the suspension due to the presence of nanoparticles was inferred to be derived from the limitation of the translational diffusion, which induces a solid-like behavior in the liquid.

European Association for Endoscopic Surgery (EAES) consensus on Indocyanine Green (ICG) fluorescence-guided surgery

BACKGROUND

In recent years, the use of Indocyanine Green (ICG) fluorescence-guided surgery during open and laparoscopic procedures has exponentially expanded across various clinical settings. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on this topic with the aim of creating evidence-based statements and recommendations for the surgical community.

METHODS

An expert panel of surgeons has been selected and invited to participate to this project. Systematic reviews of the PubMed, Embase and Cochrane libraries were performed to identify evidence on potential benefits of ICG fluorescence-guided surgery on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by the panel; they were then submitted to all EAES members through a two-rounds online survey and results presented at the EAES annual congress, Barcelona, November 2021.

RESULTS

A total of 18,273 abstracts were screened with 117 articles included. 22 statements and 16 recommendations were generated and approved. In some areas, such as the use of ICG fluorescence-guided surgery during laparoscopic cholecystectomy, the perfusion assessment in colorectal surgery and the search for the sentinel lymph nodes in gynaecological malignancies, the large number of evidences in literature has allowed us to strongly recommend the use of ICG for a better anatomical definition and a reduction in post-operative complications.

CONCLUSIONS

Overall, from the systematic literature review performed by the experts panel and the survey extended to all EAES members, ICG fluorescence-guided surgery could be considered a safe and effective technology. Future robust clinical research is required to specifically validate multiple organ-specific applications and the potential benefits of this technique on clinical outcomes.

Pulmonary Tumor Thrombotic Microangiopathy Caused by Recurrent Gastric Cancer 26 Years After Total Gastrectomy

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare cancer-related complication that induces pulmonary hypertension (PH). PTTM can be caused by recurrent cancer, with 12 years being the longest reported interval from primary cancer to the development of PTTM. We herein report a 74-year-old woman who presented with dyspnea due to PH. The postmortem diagnosis was PTTM caused by recurrent gastric cancer 26 years after total gastrectomy. An autopsy revealed PTTM-specific histological characteristics. Our findings indicate that PTTM should be considered as a diagnosis for patients with a history of cancer who develop PH, even several decades after treatment.

Q-dependent collective relaxation dynamics of glass-forming liquid Ca0.4K0.6(NO3)1.4 investigated by wide-angle neutron spin-echo

The relaxation behavior of glass formers exhibits spatial heterogeneity and dramatically changes upon cooling towards the glass transition. However, the underlying mechanisms of the dynamics at different microscopic length scales are not fully understood. Employing the recently developed wide-angle neutron spin-echo spectroscopy technique, we measured the Q-dependent coherent intermediate scattering function of a prototypical ionic glass former Ca_0.4K_0.6(NO₃)_1.4, in the highly viscous liquid state. In contrast to the structure modulated dynamics for Q < 2.4 Å⁻¹, i.e., at and below the structure factor main peak, for Q > 2.4 Å⁻¹, beyond the first minimum above the structure factor main peak, the stretching exponent exhibits no temperature dependence and concomitantly the relaxation time shows smaller deviations from Arrhenius behavior. This finding indicates a change in the dominant relaxation mechanisms around a characteristic length of 2π/(2.4 Å⁻¹) ≈ 2.6 Å, below which the relaxation process exhibits a temperature independent distribution and more Arrhenius-like behavior.

Length scale dependence is important for understanding the collective relaxation dynamics in glass-forming liquids. Here, the authors find in liquid Ca_0.4K_0.6(NO₃)_1.4 a change in the dominant relaxation mechanisms around 2.6 Å, below which the relaxation process exhibits a temperature independent distribution and more Arrhenius-like behavior.

Possible options for efficient wide-band polychromatic measurements using chopper spectrometers at pulsed sources

The polychromatic incident energy measurements using chopper spectrometers at pulsed sources enables us to measure dynamics with different energy resolutions, i.e., different time-windows with a single-measurement. By increasing the possible time-window for a single-measurement, the efficiency and usefulness of such measurements is enhanced. This is achieved by allowing the crossing of trajectories of different Eis from different source pulses on the time-of-flight diagram (the interveined trajectory). We will present an actual case of the interveined trajectory on AMATERAS, a cold-neutron chopper spectrometer installed at J-PARC, together with our experience. Some of our attempts to formulate the conditions for performing polychromatic Ei measurements employing interveined trajectories are discussed. These which can be applied to existing spectrometers, and considered as design criteria for future chopper spectrometers. Further related plan of AMATERAS to improve measuring efficiency is also mentioned.

High spatial-density, cladding-pumped 6-mode 7-core fiber amplifier for C-band operation

We present a C-band 6-mode 7-core fiber amplifier in an all-fiberized cladding-pumped configuration for space division multiplexed transmission supporting a record 42 spatial channels. With optimized fiber components (e.g. passively cooled pump laser diode, pump coupler, pump stripper), high power multimode pump light is coupled to the active fiber without any noticeable thermal degradation and an average gain of 18 dB and noise figure of 5.4 dB are obtained with an average differential modal gain of 3.4 dB.

40 Years Anniversary of Cardiac 123I-mIBG Imaging: State of the Heart

Purpose of Review

This narrative review reflects on the body of evidence on cardiac 123I-mIBG imaging that has accumulated since the introduction in the late 1970s and focusses on to what extent cardiac 123I-mIBG imaging has fulfilled its potential in cardiology especially.

Recent Findings

In contrast to the linear relationship between 123I-mIBG-derived parameters and overall prognosis in heart failure, there seems a “bell-shape” curve for 123I-mIBG-derived parameters and arrhythmic events. In addition, there is a potential clinical role for cardiac 123I-mIBG in optimizing patient selection for expensive devices (i.e., ICD and CRT). This needs of course to be established in future trials.

Summary

Cardiac 123I-mIBG imaging is, despite the numerous of studies, sometimes mistakenly seen as a nice to have technique rather than a must have imaging modality. Although cardiac 123I-mIBG imaging has grown and matured over the years, its full clinical potential has still not been tested to the maximum.

Integrated backscatter-intravascular ultrasound and modification of plaque during excimer laser coronary angioplasty

This study aims to test the hypothesis that the effect of excimer laser coronary angioplasty (ELCA) not only vaporizes thrombi and their underlying coronary plaque, it also changes their quality. We performed a series of cross-sectional analyses in 52 lesions in 51 patients before and after ELCA with integrated backscatter-intravascular ultrasound (IB-IVUS). The constituent parts of the plaque can be assessed by IB-IVUS (i.e., calcified, fibrous, lipid) according to integrated backscatter values. Minimum lumen diameter, lumen volume and vessel volume expanded after ELCA, while plaque volume did not significantly decrease. There was also a decrease of ‘lipid’ component (35.4–30.3%, P < 0.001) and an increase of IB-IVUS-derived ‘fibrous’ part (34.5–38.3%, P < 0.001). These results may help in understanding plaque change after ELCA. Excimer laser coronary angioplasty seems to contribute to the modification of coronary plaque composition in addition to debulking it.

The relation between cardiac 123I-mIBG scintigraphy and functional response 1 year after CRT implantation

Aims 

Cardiac resynchronization therapy (CRT) is a disease-modifying therapy in patients with chronic heart failure (CHF). Current guidelines ascribe CRT eligibility on three parameters only: left ventricular ejection fraction (LVEF), QRS duration, and New York Heart Association (NYHA) functional class. However, one-third of CHF patients does not benefit from CRT. This study evaluated whether ¹²³I-meta-iodobenzylguanidine (¹²³I-mIBG) assessed cardiac sympathetic activity could optimize CRT patient selection.

Methods and results 

A total of 78 stable CHF subjects (age 66.8 ± 9.6 years, 73% male, LVEF 25.2 ± 6.7%, QRS duration 153 ± 23 ms, NYHA 2.2 ± 0.7) referred for CRT implantation were enrolled. Subjects underwent ¹²³I-mIBG scintigraphy prior to implantation. Early and late heart-to-mediastinum (H/M) ratio and ¹²³I-mIBG washout were calculated. CRT response was defined as either an increase of LVEF to >35%, any improvement in LVEF of >10%, QRS shortening to <150 ms, or improvement in NYHA class of >1 class. In 33 patients LVEF increased to >35%, QRS decreased <150 ms in 36 patients, and NYHA class decreased in 33 patients. Late H/M ratio and hypertension were independent predictors of LVEF improvement to >35% (P = 0.0014 and P = 0.0149, respectively). In addition, early H/M ratio, LVEF, and absence of diabetes mellitus (DM) were independent predictors for LVEF improvement by >10%. No independent predictors were found for QRS shortening to <150 ms or improvement in NYHA class.

Conclusion 

Early and late H/M ratio were independent predictors of CRT response when improvement of LVEF was used as measure of response. Therefore, cardiac ¹²³I-mIBG scintigraphy may be used as a tool to optimize selection of subjects that might benefit from CRT.

Prognostic value of myocardial MIBG scintigraphy in acute ischemic stroke

Funding Acknowledgements

Type of funding sources: None.

Background Autonomic dysfunction is a common complication of acute ischemic stroke and has been associated with poor functional outcome and increased mortality. We investigated the potential relation between the myocardial washout rate (WOR) of 123I-meta-iodobenzylguanidine (123I-mIBG), as a measure of cardiac sympathetic activity, and functional outcome in acute ischemic stroke. 

Methods 38 patients with ischemic stroke (11 females, 72 years old [61-81)), underwent myocardial 123I-mIBG scintigraphy within the first week after stroke onset. Early (10 minutes post-injection (pi)) and late (4 hours pi) planar scans of the thoracic region were made. Regions of interest (ROI) were drawn over the mediastinum and the heart, and heart-to-mediastinum ratio (HMR) was calculated. Myocardial WOR was calculated as follows: (ROI heart early – ROI heart late)/ (ROI heart early) x 100%. Counts were corrected for background and counts in ROI heart late were corrected for decay. Patients were divided in 2 groups: those with a good functional outcome, defined as modified Rankin Scale (mRS) ≤ 2 at 3 months after stroke (i.e., patient is functionally independent), and those with a poor functional outcome, defined as a mRS &gt; 2. 

Results Median WOR was 27,4 % (IQR 10,4-43,6). In univariate analysis, poor functional outcome after stroke was associated with age, stroke severity on admission (measured by the National Institutes of Health Stroke Scale (NIHSS)), beta-blocker use before and during hospitalization, WOR and late HMR. In subsequent multivariate analysis WOR (OR 1.087; 95% CI 1.003-1.177, p = 0.042) was an independent predictor of poor stroke outcome even after adjustment for age and NIHSS.

Conclusions In patients with acute ischemic stroke, myocardial washout of 123I-mIBG predicts stroke outcome, even after adjustment for age and stroke severity on admission.

Radiomics analysis of myocardial perfusion SPECT images in patients with cardiomyopathy and heart failure

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): JSPS KAKENHI Grants

Background

Although myocardial perfusion heterogeneity due to focally damaged cardiomyocytes is observed in single−photon emission computed tomography (SPECT) imaging, a current perfusion defect scoring system does not allow us to provide sufficient diagnostic information for heterogeneity.

Purpose

The aim of this study was to perform radiomics analysis of myocardial perfusion SPECT (MPS) images to investigate the potential to detect myocardial perfusion heterogeneity.

Methods

Patients with hypertrophic cardiomyopathy (n = 3), heart failure (n = 9), and with a low likelihood of coronary artery disease (n =15) (Figure 1), who underwent a rest 99mTc-MIBI myocardial perfusion SPECT, were assessed using a LIFEx software. Four shape−based features, 6 histogram−based features, and 32 textural features were computed. The relevant features for the classification of the patients were selected using the Boruta algorithm, and hierarchical clustering of the selected features using the Spearman correlation coefficient was also performed for the feature reduction. The receiver operating characteristics (ROC) analysis was performed by the support vector machine to calculate the area under the ROC curve (AUC) for the selected features.

Results

Of 40 features, 17 were selected by the classification analysis, and these features were classified into 7 classes by the correlation analysis (Figure 2). The ROC AUCs for 7 features extracted from each class were 0.99, 0.97, 0.96, 0.92, 0.90, 0.86, and 0.83 for the contrast of NDGLDM, the entropy of histogram, ZLNU of GLZLM, the energy of GLCM, the energy of histogram, SZLGE of GLZLM, and the correlation of GLCM, respectively, as compared to 0.39 for a summed rest score.

Conclusions

Radiomics analysis successfully determined the myocardial perfusion heterogeneity in patients with cardiomyopathy and heart failure. It might be promising for the evaluation of myocardial damages that cannot be analyzed by the conventional scoring method.

Creation of mortality risk calculator using a I-123 mIBG-based machine learning model: differential prediction of arrhythmic death and heart-failure death

Funding Acknowledgements

Type of funding sources: None.

Background

Although I-123 meta-iodobenzylguanidine (mIBG) has been applied to patients with chronic heart failure (CHF), a diagnostic tool for differential prediction of fatal arrhythmic events (ArE) and heart-failure death (HFD) has been pursued. 

Purpose

The aim of this study was to create a calculator of mortality risk for differentiating mode of cardiac death using a machine learning (ML) method, and to test the accuracy in a new cohort of patients with CHF.

Methods

A total of 529 patients with CHF was used as the training database for ML. The ArE group consisted of patients with arrhythmic death, sudden cardiac death and appropriate therapy by implantable cardioverter defibrillator. A heart-to-mediastinum ratio (H/M) standardized to the medium-energy collimator condition was calculated with a planar anterior mIBG scintigram. The best classifier models for predicting HFD and ArE were determined by four-fold cross validation. Input variables included age, sex, New York Heart Association (NYHA) functional class, left ventricular ejection fraction, ischemic etiology, mIBG H/M and washout rate, and b-type natriuretic peptide (BNP) or NT Pro BNP, estimated glomerular filtration rate, hemoglobin, and complications such as diabetes and hypertension. After creating the ML-based model, the constructed classifier functions for ArE, HFD, and survival were exported for subsequent use. A new cohort of patients (n = 312, age 67 ± 13 years, 2015 or later) was used to test the ML-based model.

Results

The training database included 141 events (27%) with ArE (7%) and HFD (20%). Receiver-operating characteristic analysis by four-fold validation showed area under the curve value of 0.90 for HFD and 0.73 for ArE. Among various ML methods, the logistic regression method demonstrated the most stable calculation of the probability of ArE followed by random forest and gradient boosted tree methods. Therefore, the logistic-regression method was used for calculating both HFD and ArE probabilities. In the test cohort, patients with a high HFD probability &gt;8% resulted in 6.3-fold higher HFD than those with low probability (≤ 8%). Patients with high ArE probability &gt;8% showed 2.5-fold higher ArE than those with low probability (≤ 8%).

Conclusion

The ML-based mortality risk calculator could be used for stratifying patients at high and low risks, which might be useful for estimating appropriate treatment strategy.

Dimensional reduction by geometrical frustration in a cubic antiferromagnet composed of tetrahedral clusters

Dimensionality is a critical factor in determining the properties of solids and is an apparent built-in character of the crystal structure. However, it can be an emergent and tunable property in geometrically frustrated spin systems. Here, we study the spin dynamics of the tetrahedral cluster antiferromagnet, pharmacosiderite, via muon spin resonance and neutron scattering. We find that the spin correlation exhibits a two-dimensional characteristic despite the isotropic connectivity of tetrahedral clusters made of spin 5/2 Fe3+ ions in the three-dimensional cubic crystal, which we ascribe to two-dimensionalisation by geometrical frustration based on spin wave calculations. Moreover, we suggest that even one-dimensionalisation occurs in the decoupled layers, generating low-energy and one-dimensional excitation modes, causing large spin fluctuation in the classical spin system. Pharmacosiderite facilitates studying the emergence of low-dimensionality and manipulating anisotropic responses arising from the dimensionality using an external magnetic field.

Spin glass behavior and magnetic boson peak in a structural glass of a magnetic ionic liquid

Glassy magnetic behavior has been observed in a wide range of crystalline magnetic materials called spin glass. Here, we report spin glass behavior in a structural glass of a magnetic ionic liquid, C4mimFeCl4. Magnetization measurements demonstrate that an antiferromagnetic ordering occurs at TN = 2.3 K in the crystalline state, while a spin glass transition occurs at TSG = 0.4 K in the structural glass state. In addition, localized magnetic excitations were found in the spin glass state by inelastic neutron scattering, in contrast to spin-wave excitations in the ordered phase of the crystalline sample. The localized excitation was scaled by the Bose population factor below TSG and gradually disappeared above TSG. This feature is highly reminiscent of boson peaks commonly observed in structural glasses. We suggest the "magnetic" boson peak to be one of the inherent dynamics of a spin glass state.

Relevance of hydrogen bonded associates to the transport properties and nanoscale dynamics of liquid and supercooled 2-propanol

2-Propanol was investigated, in both the liquid and supercooled states, as a model system to study how hydrogen bonds affect the structural relaxation and the dynamics of mesoscale structures, of approximately several Ångstroms, employing static and quasi-elastic neutron scattering and molecular dynamics simulation. Dynamic neutron scattering measurements were performed over an exchanged wave-vector range encompassing the pre-peak, indicative of the presence of H-bonding associates, and the main peak. The dynamics observed at the pre-peak is associated with the formation and disaggregation of the H-bonded associates and is measured to be at least one order of magnitude slower than the dynamics at the main peak, which is identified as the structural relaxation. The measurements indicate that the macroscopic shear viscosity has a similar temperature dependence as the dynamics of the H-bonded associates, which highlights the important role played by these structures, together with the structural relaxation, in defining the macroscopic rheological properties of the system. Importantly, the characteristic relaxation time at the pre-peak follows an Arrhenius temperature dependence whereas at the main peak it exhibits a non-Arrhenius behavior on approaching the supercooled state. The origin of this differing behavior is attributed to an increased structuring of the hydrophobic domains of 2-propanol accommodating a more and more encompassing H-bond network, and a consequent set in of dynamic cooperativity.

Lead-free MCP to improve coincidence time resolution and reduce MCP direct interactions

Achieving direct imaging of the annihilation position of a positron on an event-by-event basis using an ultrafast detector would have a great impact on the field of nuclear medicine. Cherenkov emission is the most attractive physical phenomenon for realizing such an ultrafast timing performance. Moreover, a microchannel-plate photomultiplier tube (MCP-PMT) is one of the most promising photodetectors for fully exploiting the fast timing properties of Cherenkov emission owing to its excellent single photon time resolution of 25 ps full width at half maximum (FWHM). However, as the MCP structure generally contains a lead compound, the gamma rays frequently and directly interact with the MCP, resulting in the degradation of its timing performance and generation of undesirable side peaks in its coincidence timing histogram. To overcome this problem, we have developed a new MCP-PMT based on an MCP consisting of borosilicate glass, thus drastically reducing the probability of the photoelectric effect occurring in the MCP. To evaluate its insensitivity to gamma rays and its timing performance, a coincidence experiment was performed and showed that the probability of direct interactions was reduced by a factor of 3.4. Moreover, a coincidence time resolution of 35.4 ± 0.4 ps FWHM, which is equivalent to a position resolution of 5.31 mm, was obtained without any pulse height/area cut, improving to 28.7 ± 3.0 ps when selecting on the highest amplitude events by careful optimization of the voltage divider circuit of the new MCP-PMT. The timing performance of this new MCP-PMT presents an important step toward making direct imaging possible.

Freezable and Unfreezable Hydration Water: Distinct Contributions to Protein Dynamics Revealed by Neutron Scattering

Hydration water plays a crucial role for activating the protein dynamics required for functional expression. Yet, the details are not understood about how hydration water couples with protein dynamics. A temperature hysteresis of the ice formation of hydration water is a key phenomenon to understand which type of hydration water, unfreezable or freezable hydration water, is crucial for the activation of protein dynamics. Using neutron scattering, we observed a temperature-hysteresis phenomenon in the diffraction peaks of the ice of freezable hydration water, whereas protein dynamics did not show any temperature hysteresis. These results show that the protein dynamics is not coupled with freezable hydration water dynamics, and unfreezable hydration water is essential for the activation of protein dynamics. Decoupling of the dynamics between unfreezable and freezable hydration water could be the cause of the distinct contributions of hydration water to protein dynamics.

Neutron Spin-Echo Studies of the Structural Relaxation of Network Liquid ZnCl2 at the Structure Factor Primary Peak and Prepeak

Using neutron spin-echo spectroscopy, we studied the microscopic structural relaxation of a prototypical network ionic liquid ZnCl₂ at the structure factor primary peak and prepeak. The results show that the relaxation at the primary peak is faster than the prepeak and that the activation energy is ∼33% higher. A stretched exponential relaxation is observed even at temperatures well-above the melting point T_m. Surprisingly, the stretching exponent shows a rapid increase upon cooling, especially at the primary peak, where it changes from a stretched exponential to a simple exponential on approaching the T_m. These results suggest that the appearance of glassy dynamics typical of the supercooled state even in the equilibrium liquid state of ZnCl₂ as well as the difference of activation energy at the two investigated length scales are related to the formation of a network structure on cooling.

REACTOR PHYSICS EXPERIMENT IN A GRAPHITE-MODERATION SYSTEM FOR HTGR

The Japan Atomic Energy Agency (JAEA) started the Research and Development (R&D) to improve nuclear prediction techniques for High Temperature Gas-cooled Reactors (HTGRs). The objectives are to introduce a generalized bias factor method to avoid full mock-up experiment for the first commercial HTGR and to introduce reactor noise analysis to High Temperature Engineering Test Reactor (HTTR) experiment to observe sub-criticality. To achieve the objectives, the reactor core of graphite-moderation system named B7/4”G2/8”p8EUNU+3/8”p38EU(1) was newly composed in the B-rack of Kyoto University Critical Assembly (KUCA). The core is composed of the fuel assembly, driver fuel assembly, graphite reflector, and polyethylene reflector. The fuel assembly is composed of enriched uranium plate, natural uranium plate and graphite plates to realize the average fuel enrichment of HTTR and it’s spectrum. However, driver fuel assembly is necessary to achieve the criticality with the small-sized core. The core plays a role of the reference core of the bias factor method, and the reactor noise was measured to develop the noise analysis scheme. In this study, the overview of the criticality experiments is reported. The reactor configuration with graphite moderation system is rare case in the KUCA experiments, and this experiment is expected to contribute not only for an HTGR development but also for other types of a reactor in the graphite moderation system such as a molten salt reactor development.

Ventricular tachycardia in cardiac sarcoidosis -prognosis, characterization of ventricular substrates and outcomes of treatment-

Background

The prognosis, the underlying substrate and clinical outcomes of treatment are unclear in patients with cardiac sarcoidosis (CS)-related ventricular tachycardia (VT).

Objective

This study investigated the prognosis and the relationship between electroanatomical mapping (EAM) and imaging findings in patients with CS-related VT.

Methods

A total of 203 CS patients (Age 68.1±11.6 years, 87 males) were enrolled at two tertiary care medical centers between 2000 and 2018. All met the 2016 Japanese Circulation Society guidelines for diagnosis of CS. They were followed for a composite of major adverse cardiac events (MACE) including cardiac death, heart transplantation, unscheduled hospitalization for heart failure, and life-threatening ventricular arrhythmias. Distribution of late gadolinium enhancement (LGE) on cardiac MRI (CMR) and/or an abnormal myocardial 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography at diagnosis were examined. The relationship between EAM and the image findings were also analyzed in patients with radiofrequency ablation (RFA) for VT.

Results

During a median follow-up of 53 months, 87 of the 203 patients (43%) experienced a MACE. Baseline factors associated with MACE were presence of sustained VT (HR, 2.43, 95% CI 1.54–3.85, P&lt;0.001), left ventricular ejection fraction below 50% (HR, 1.95 95% CI 1.07–3.56, P=0.029), and abnormal myocardial FDG uptake (HR, 2.42 95% CI 1.04–5.61, P=0.039). Overall, 69 of the 203 patients (34%) experienced sustained VT. Abnormal myocardial FDG uptake was significantly more prevalent in patients with VT than in those without (92.7% vs. 78.5%, P=0.02). A total of 25 patients (9.9%) required RFA for CS-related VT (Age 64.0±8.7 years, 12 males, 1.32±0.56 RFAs per patient). Abnormal electrocardiograms (EGM) were observed in 22 of the 25 patients (88%). LGE was more frequent than abnormal FDG uptake in areas with an abnormal EGM (77% vs. 41%; P=0.002). Over a mean follow-up period of 67-months, 13 of the 25 patients with RFA (52%) remained free of VT episodes (Figure). VT recurred in nine of the 12 patients with RFA and in 17 of the 47 patients without RFA, but was suppressed by intensive pharmacologic therapy such as the combined use of amiodarone and sotalol. In patients with CS-related VT, survival without experiencing a MACE did not differ in participants with or without RFA.

Conclusions

In our 203 CS patients, sustained VT and abnormal FDG uptake were associated with worse cardiac outcomes. The prevalence of abnormal FDG uptake was significantly higher in patients with CS-related VT, LGE on CMR was more frequent within localized areas of an abnormal EGM, suggesting that both scar itself and the associated inflammation were involved in the pathogenesis of CS-related VT. Successful RFA of CS-related VT is still challenging, and recurrence is common. Preprocedural CMR can be useful in detecting abnormal EGMs that are potential targets for substrate ablation.

Funding Acknowledgement

Type of funding source: None

Cardiac function at diagnosis is important prognostic factor in patients with cardiac sarcoidosis -from Japanese nationwide questionnaire survey-

Background

Sarcoidosis is a systemic non-caseating granulomatous disease of unknown etiology. Cardiac involvement (cardiac sarcoidosis, CS) has been reported to be an important prognostic factor in this disease because of heart failure and/or ventricular arrhythmia, and corticosteroid therapy is usually prescribed to prevent cardiac events. However, little is known about the relationship of cardiac function and concomitant corticosteroid therapy on later cardiac events in CS.

Objective

We evaluated the relationship between prognosis and left ventricular ejection fraction (LVEF) at the time of diagnosis in CS patients from the Japanese nationwide questionnaire survey.

Methods

Total of 757 Japanese patients from 57 hospitals who diagnosed CS were examined. Patients who unsatisfied the criteria of the Japanese new guidelines, or who underwent cardiac transplantations were excluded, and 420 patients (287 females, mean age 60±13 years old, median follow-up periods 1864 days [interquartile range: 845–3159 days]) were analyzed. The relationship of adverse events (all-cause death, cardiovascular death, and appropriate ICD [Implantable Cardioverter Defibrillator] discharge) and LVEF (with corticosteroid 84%) (low LVEF: LVEF≤35% n=98 [with corticosteroid in 78%], moderate LVEF: LVEF 35–50% n=104 [with corticosteroid in 93%], normal LVEF: 50≤LVEF n=218 [with corticosteroid in 83%]) were evaluated respectively.

Results

89 CS patients developed all-cause death (n=50), cardiovascular death (n=30) or appropriate ICD discharge (n=48). The frequency of corticosteroid therapy was not different in the each LVEF group, but Kaplan-Meier analysis revealed that all-cause death, cardiovascular death, and all cardiovascular adverse events were more observed in lower LVEF group (log-rank p&lt;0.0001). Furthermore, multivariate Cox hazard analysis revealed that LVEF was a most important independent prognostic factor in CS.

Conclusion

This Japanese nationwide questionnaire survey data showed that initial LVEF was an independent and strong prognostic predictor in CS, therefore primary prevention would be needed even after starting corticosteroid in patients with decreased cardiac function.

Funding Acknowledgement

Type of funding source: None

Long time clinical course of cardiac sarcoidosis with corticosteroid therapy -from Japanese nationwide questionnaire survey-

Background

Sarcoidosis is a systemic inflammatory syndrome of unknown etiology and cardiac involvement has been reported to be an important prognostic factor in this disease. An autopsy study has reported that the frequency of this cardiac involvement (cardiac sarcoidosis: CS) varies in the different countries and races and very frequent in Japanese patients. We therefore performed the nationwide questionnaire survey and try to clarify the clinical characteristics and corticosteroid effect in CS, especially focused on arrhythmic events in this disease.

Methods

Total of 757 Japanese patients from 57 hospitals who diagnosed CS were examined. Patients who unsatisfied the criteria of the Japanese new guidelines, or who underwent cardiac transplantations were excluded, and 420 patients (287 females, median follow-up periods 1864 days [interquartile range: 845–3159 days]) were analyzed. The clinical outcome and corticosteroid effect were evaluated.

Results

Clinical characteristics at diagnosis was as follows: female dominant (68%), mean age of 60±13 years old, mean left ventricular ejection fraction was 49±16%. Arrhythmic events were very frequently observed as an initial cardiac manifestation in 263 patients (62%) of CS, of which atrioventricular block (AVB) in 174 (41%), ventricular tachycardia (VT) in 73 (17%) and AVB with VT in 17 (4%) (Figure 1A). Pacemaker was implanted in 166 patients (40%) and defibrillators was 137 patients (33%). Corticosteroid was prescribed in 144 (83%) of 174 patients with AVB and in 62 (85%) of 73 patients with VT. Initial dose was mean 47.9 mg and maintenance dose of mean 7.3 mg. Corticosteroid improved VT as good as AVB (27% vs. 29%). However, corticosteroid sometimes worsened VT events compared with AVB (10% vs. 2%) (Figure 1B). During the course of follow-up, 32 patients were needed to increase corticosteroid in 23 of AVB and 10 of VT cases. However, there were no difference in mortality between the groups, whether or not to increase corticosteroid. All survival rate was 92% (5-year mortality), 83% (10-year mortality) and free from all cause death and defibrillator charge was 81% (5 year), 71% (10 year).

Conclusion

Fatal arrhythmia is commonly observed in CS as a primary symptom. Corticosteroid sometimes worsen ventricular arrhythmia and appropriate defibrillator discharge was common. Thus, careful attention for activating ventricular arrhythmia would be needed during the follow-up period even after corticosteroid therapy.

Funding Acknowledgement

Type of funding source: None

Long-term follow up ventricular tachycardia patients with preserved cardiac function -from Japanese cardiac sarcoidosis nationwide questionnaire survey-

Background

Prior ventricular tachycardia (VT) and low left ventricular ejection fraction (LVEF) are the most important prognostic factors in cardiac sarcoidosis (CS). Recently diagnosis of CS was renewed according to Japanese new guidelines. Patients with preserved cardiac function often have VT events, thus new guidelines recommends to assess the implantable cardioverter defibrillator (ICD) implantation for CS patients with preserved LVEF (35%≤LVEF&lt;50%). However, the long-term prognosis of CS patients with preserved LVEF is unclear.

Objective

In CS patients with preserved LVEF, we evaluated the prognosis between VT manifestation and non-VT manifestation groups at CS diagnosis from Japanese nationwide questionnaire survey.

Methods

Total of 757 Japanese patients from 57 hospitals who diagnosed CS were examined. Patients who unsatisfied the criteria of the Japanese new guidelines, who had LVEF≤35%, LVEF&gt;50%, or who underwent cardiac transplantations were excluded. 104 patients with LVEF 35–50% (67 females, mean age 60±15 years old, median follow-up periods 2134 days [interquartile range: 758–2935 days]) were analyzed. The prognosis between VT manifestation and non-VT manifestation groups at CS diagnosis were evaluated.

Results

30 patients had VT manifestation at CS diagnosis and 24 patients (80%) received ICDs. 74 patients had no VT manifestation at CS diagnosis and 19 patients (44%) received ICDs during follow up period. All-cause mortality was not different between two groups (Figure). Appropriate ICD therapy of non-VT manifestation group was significantly lower compared with that of VT manifestation group (log-rank p=0.001), however considerable number (n=7, 15%) of non-VT manifestation group had appropriate ICD therapy event during follow-up period. Cox hazard analysis revealed that concomitant non-sustained VT (NSVT) with atrioventricular block (AVB) was a predictor of appropriate ICD therapy in non-VT manifestation group.

Conclusion

This nationwide survey showed that considerable number of CS patients with preserved LVEF had VT events, independent of VT manifestation. Concomitant NSVT with AVB was a predictor of VT events, and ICD implantation should be assessed.

Funding Acknowledgement

Type of funding source: None

Micro-embolic risks during radiofrequency and cryoballoon-ablation of atrial fibrillation -analysis from real-time carotid artery doppler monitoring-

Background

Catheter ablation of atrial fibrillation (AF) is associated with risks of silent cerebral events. However, the timing of intraprocedural micro-embolic events or differences between open-irrigated radiofrequency (RF) and cryoballoon (Cryo) ablation are unclear. Newly developed real-time carotid artery Doppler is a simple non-invasive method to detect micro-embolic signals (MESs) during ablation.

Objective

We investigated the timing of detecting MESs during RF and Cryo ablation of AF.

Methods

During the first pulmonary vein isolation (PVI) session of AF, MESs were monitored by real-time carotid artery Doppler monitoring throughout the procedure. The MES counts were collected and evaluated separately during the different steps of the procedure (Figure).

Results

Thirty-three AF patients (RF/Cryo: 22/11 cases, 9 females, 69.5±11.6 y.o) were included. PVI was successfully accomplished in all patients with no major complications. The MES count was significantly greater in the RF group than Cryo group (table). In both groups, left atrial (LA) access (interatrial puncture) and sheaths insertion to the LA generated a significant number of MESs (RF: 1690 of 9116 MESs [18.5% of the total MESs], Cryo: 793 of 2285 MESs [34.7%]). In the RF group, MESs were observed incessantly during PVI (Figure). The LA dwell time was significantly longer in the RF group than Cryo group (table). In the RF group, the MES count was significantly greater in the longer LA dwell time group (LA dwell time &gt;130min) than the shorter group (464.2±179.7 vs 302.6±138.2: P=0.049). During the cryo-applications in the Cryo group, the MESs were greatest during the first cryoballoon application (625 of 2285 MESs [27.4%]).

Conclusions

There were more MESs during RF ablation than cryoablation. MESs were recorded during a variety of steps throughout the procedure. In the RF group, most of MESs were recorded incessantly during radiofrequency ablation and greater number of MESs were recorded in patients with longer LA dwell time. In the Cryo group, most of MESs occurred during phases with a high probability of gaseous emboli.

Funding Acknowledgement

Type of funding source: None

The safety of catheter ablation of atrial fibrillation in elderly patients -analysis of the nationwide database in Japan, JROAD-DPC-

Background

“Age” is one of the major concerns and determinants of the indications for catheter ablation (CA) of atrial fibrillation (AF). There are little safety data on CA of AF according to the age. This study aimed to assess the safety of CA in elderly patients undergoing CA of AF.

Methods and results

We investigated the complication rate of CA of AF for the different age groups (&lt;60 years, 60–65, 65–70, 70–75, 75–80, 80–85, and ≥85) by a nationwide database (Japanese Registry Of All cardiac and vascular Diseases [JROAD]-DPC). The JROAD-DPC included 73,296 patients (65±11 years, 52,883 men) who underwent CA of AF from 516 hospitals in Japan. Aged patients had more comorbidities and a significantly increased CHADS2 score and higher rate of female according to a higher age. The overall complication rate was 2.6% and in-hospital mortality was 0.05%. By comparing each age group, complications occurred more frequently in higher aged groups. A multivariate adjusted hazard ratio revealed an increased age was independently and significantly associated with the overall complications (odds ratio was 1.25, 1.35, 1.72, 1.86, 2.76 and 3.13 respectively; reference &lt;60 years).

Conclusions

The frequency of complications was significantly higher according to a higher age. We should take note of the indications and procedure for CA of AF in aged patients.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Intramural Research Fund 17 (Kusano) for Cardiovascular Diseases of the National Cerebral and Cardiovascular Center

Gapless spin liquid in a square-kagome lattice antiferromagnet

Observation of a quantum spin liquid (QSL) state is one of the most important goals in condensed-matter physics, as well as the development of new spintronic devices that support next-generation industries. The QSL in two dimensional quantum spin systems is expected to be due to geometrical magnetic frustration, and thus a kagome-based lattice is the most probable playground for QSL. Here, we report the first experimental results of the QSL state on a square-kagome quantum antiferromagnet, KCu6AlBiO4(SO4)5Cl. Comprehensive experimental studies via magnetic susceptibility, magnetisation, heat capacity, muon spin relaxation (μSR), and inelastic neutron scattering (INS) measurements reveal the formation of a gapless QSL at very low temperatures close to the ground state. The QSL behavior cannot be explained fully by a frustrated Heisenberg model with nearest-neighbor exchange interactions, providing a theoretical challenge to unveil the nature of the QSL state.

Motion tracking of 80-nm-size skyrmions upon directional current injections

Nanometer-scale skyrmions are prospective candidates for information bits in low-power consumption devices owing to their topological nature and controllability with low current density. Studies on skyrmion dynamics in different classes of materials have exploited the topological Hall effect and current-driven fast motion of skyrmionic bubbles. However, the small current track motion of a single skyrmion and few-skyrmion aggregates remains elusive. Here, we report the tracking of creation and extinction and motion of 80-nm-size skyrmions upon directional one-current pulse excitations at low current density of the order of 109 A m-2 in designed devices with the notched hole. The Hall motion of a single skyrmion and the torque motions of few-skyrmion aggregates have been directly revealed. The results exemplify low-current density controls of skyrmions, which will pave the way for the application of skyrmions.