Prevalence and electrocardiographic and electrophysiological characteristics of idiopathic ventricular arrhythmias originating from the septal left ventricular summit.

INTRODUCTION: The left ventricular summit (LVS) is the highest point on the epicardial surface of the left ventricle. A part of the LVS that is located between the left coronary arteries (lateral-LVS) is one of the major sites of idiopathic ventricular arrhythmia (VA) origins. Some idiopathic epicardial VAs can be ablated at endocardial sites adjacent to the epicardial area septal to the lateral-LVS (septal-LVS). This study examined the prevalence and electrocardiographic and electrophysiological characteristics of septal-LVS VAs. METHODS: We studied consecutive patients with idiopathic VAs originating from the LVS (67 patients) and aortic root (93 patients). RESULTS: Based on the ablation results, among 67 LVS VAs, 54 were classified as lateral and 13 as septal-LVS VAs. As compared with the lateral-LVS VAs, the septal-LVS VAs were characterized by a greater prevalence of left bundle branch block with left inferior-axis QRS pattern, later precordial transition, lower R-wave amplitude ratio in leads III to II, lower Q-wave amplitude ratio in leads aVL to aVR, and later local ventricular activation time relative to the QRS onset during VAs (V-QRS) in the great cardiac vein. The electrocardiographic and electrophysiological characteristics of the septal-LVS VAs were similar to those of the aortic root VAs. However, the V-QRS at the successful ablation site was significantly later during the septal-LVS VAs than aortic root VAs (p < .0001). The precordial transition was significantly later during the septal-LVS VAs than aortic root VAs (p < .05). CONCLUSIONS: Septal-LVS VAs are considered a distinct subgroup of idiopathic VAs originating from the left ventricular outflow tract.

Prediction of patient-specific quality assurance for volumetric modulated arc therapy using radiomics-based machine learning with dose distribution.

PURPOSE: We sought to develop machine learning models to predict the results of patient-specific quality assurance (QA) for volumetric modulated arc therapy (VMAT), which were represented by several dose-evaluation metrics-including the gamma passing rates (GPRs)-and criteria based on the radiomic features of 3D dose distribution in a phantom. METHODS: A total of 4,250 radiomic features of 3D dose distribution in a cylindrical dummy phantom for 140 arcs from 106 clinical VMAT plans were extracted. We obtained the following dose-evaluation metrics: GPRs with global and local normalization, the dose difference (DD) in 1% and 2% passing rates (DD1% and DD2%) for 10% and 50% dose threshold, and the distance-to-agreement in 1-mm and 2-mm passing rates (DTA1 mm and DTA2 mm) for 0.5%/mm and 1.0%.mm dose gradient threshold determined by measurement using a diode array in patient-specific QA. The machine learning regression models for predicting the values of the dose-evaluation metrics using the radiomic features were developed based on the elastic net (EN) and extra trees (ET) models. The feature selection and tuning of hyperparameters were performed with nested cross-validation in which four-fold cross-validation is used within the inner loop, and the performance of each model was evaluated in terms of the root mean square error (RMSE), the mean absolute error (MAE), and Spearman's rank correlation coefficient. RESULTS: The RMSE and MAE for the developed machine learning models ranged from <1% to nearly <10% depending on the dose-evaluation metric, the criteria, and dose and dose gradient thresholds used for both machine learning models. It was advantageous to focus on high dose region for predicating global GPR, DDs, and DTAs. For certain metrics and criteria, it was possible to create models applicable for patients' heterogeneity by training only with dose distributions in phantom. CONCLUSIONS: The developed machine learning models showed high performance for predicting dose-evaluation metrics especially for high dose region depending on the metric and criteria. Our results demonstrate that the radiomic features of dose distribution can be considered good indicators of the plan complexity and useful in predicting measured dose evaluation metrics.

Tripodal Triazatruxene Derivative as a Face-On Oriented Hole-Collecting Monolayer for Efficient and Stable Inverted Perovskite Solar Cells.

Hole-collecting monolayers have drawn attention in perovskite solar cell research due to their ease of processing, high performance, and good durability. Since molecules in the hole-collecting monolayer are typically composed of functionalized π-conjugated structures, hole extraction is expected to be more efficient when the π-cores are oriented face-on with respect to the adjacent surfaces. However, strategies for reliably controlling the molecular orientation in monolayers remain elusive. In this work, multiple phosphonic acid anchoring groups were used to control the molecular orientation of a series of triazatruxene derivatives chemisorbed on a transparent conducting oxide electrode surface. Using infrared reflection absorption spectroscopy and metastable atom electron spectroscopy, we found that multipodal derivatives align face-on to the electrode surface, while the monopodal counterpart adopts a more tilted configuration. The face-on orientation was found to facilitate hole extraction, leading to inverted perovskite solar cells with enhanced stability and high-power conversion efficiencies up to 23.0%.

Temperature dependence of photoluminescence spectrum of single lead halide perovskite nanocrystals: Effect of size on the phase transition temperature.

Photoluminescence (PL) spectroscopy of individual semiconductor nanocrystals (NCs) is a powerful method for understanding the intrinsic optical properties of these materials. Here, we report the temperature dependence of the PL spectra of single perovskite FAPbBr3 and CsPbBr3 NCs [FA = HC(NH2)2]. The temperature dependences of the PL linewidths were mainly determined by the Fröhlich interaction between excitons and longitudinal optical phonons. For FAPbBr3 NCs, a redshift in the PL peak energy appeared between 100 and 150 K, which was because of the orthorhombic-to-tetragonal phase transition. We found that the phase transition temperature of FAPbBr3 NCs decreases with decreasing NC size.

Deep learning-based detection and classification of multi-leaf collimator modeling errors in volumetric modulated radiation therapy.

PURPOSE: The purpose of this study was to create and evaluate deep learning-based models to detect and classify errors of multi-leaf collimator (MLC) modeling parameters in volumetric modulated radiation therapy (VMAT), namely the transmission factor (TF) and the dosimetric leaf gap (DLG). METHODS: A total of 33 clinical VMAT plans for prostate and head-and-neck cancer were used, assuming a cylindrical and homogeneous phantom, and error plans were created by altering the original value of the TF and the DLG by ± 10, 20, and 30% in the treatment planning system (TPS). The Gaussian filters of σ = 0.5 $\sigma = 0.5$ and 1.0 were applied to the planar dose maps of the error-free plan to mimic the measurement dose map, and thus dose difference maps between the error-free and error plans were obtained. We evaluated 3 deep learning-based models, created to perform the following detections/classifications: (1) error-free versus TF error, (2) error-free versus DLG error, and (3) TF versus DLG error. Models to classify the sign of the errors were also created and evaluated. A gamma analysis was performed for comparison. RESULTS: The detection and classification of TF and DLG error were feasible for σ = 0.5 $\sigma = 0.5$ ; however, a considerable reduction of accuracy was observed for σ = 1.0 $\sigma = 1.0$ depending on the magnitude of error and treatment site. The sign of errors was detectable by the specifically trained models for σ = 0.5 $\sigma = 0.5$ and 1.0. The gamma analysis could not detect errors. CONCLUSIONS: We demonstrated that the deep learning-based models could feasibly detect and classify TF and DLG errors in VMAT dose distributions, depending on the magnitude of the error, treatment site, and the degree of mimicked measurement doses.

Exciton-Phonon and Trion-Phonon Couplings Revealed by Photoluminescence Spectroscopy of Single CsPbBr3 Perovskite Nanocrystals.

Lead halide perovskite nanocrystals (NCs) have outstanding photoluminescence (PL) properties and excellent potential for light-emitting diodes and single-photon sources. Here, we report the multiple-peak structures originating from excitons, trions, and biexcitons in low-temperature PL spectra of single CsPbBr3 NCs. We found fine-structure splitting in the PL peaks of bright excitons and biexcitons and also in the longitudinal-optical (LO)-phonon replicas of excitons. LO-phonon replicas of trions are clearly observed under strong photoexcitation, which do not show fine-structure splitting. From size-dependent analyses of these replicas, we clarified that both exciton-phonon and trion-phonon couplings become larger for smaller NCs and the coupling strengths of trions are larger than those of excitons in large NCs. These behaviors can be explained by the spatial distributions of the electron and hole wave functions in the NCs. Our findings provide essential information on electron-phonon couplings in perovskites and for the design of high-purity single-photon sources.

Changes in physical function of frail elderly females in the one-year long-term care prevention program.

[Purpose] This study investigated changes in the physical function of frail elderly females who participated in a long-term care prevention project for ≥1 year. [Participants and Methods] There were 125 females included. Measurement items were body mass index, 5-m maximum gait time, 5-m normal gait time, standing on one leg with eyes open, timed up and go test, and grip strength and measured every six months. [Results] Grip strength decreased significantly after six months and one year compared to that of the start. The other measurements had no significant differences at start, after six months, and after one year. [Conclusion] This study investigated changes in physical functions in the frail community-dwelling elderly females one year after starting in a long-term prevention care program. Consequently, after one year in the program, no change was noted in measurements, such as gait speed, but only grip strength decreased. Likely, the exercise program mainly targeted the lower limb muscles. Therefore, although functions mainly use the lower limbs, such as walking, may be maintained, those using the upper limbs may be affected by aging.

Biomechanical gait analysis for a hip disarticulation prosthesis: power source for the swing phase of a hip disarticulation prosthetic limb.

[Purpose] This study aimed to clarify the power source for the swing phase of a hip disarticulation prosthetic limb using biomechanical gait analysis. [Participants and Methods] In this cross-sectional study, six participants who underwent hip disarticulation and seven healthy adults were recruited. Their gaits were assessed using the three-dimensional motion analysis and four force plates. [Results] From pre-swing to initial swing, the angle of the lumbar spine's angle changed by 9° from the flexion to extension positions. However, the power of the lumbar spine was <0.003 W/kg for the entire gait cycle. The peak value of joint moment and hip joint power on the unaffected side were 1 nm/kg and 0.7 W/kg, respectively. From pre-swing to initial swing, the prosthetic limb is pushed forward by extension of the hip joint on the intact side, while the spine returns to the flexion direction. [Conclusion] The hip extension force on the unaffected side was the main force responsible for swinging out the prosthesis, not the lumbar vertebrae's force.

Association between knee function and kinesiophobia 6 months after anterior cruciate ligament reconstruction.

[Purpose] Kinesiophobia after anterior cruciate ligament reconstruction has been identified as an inhibitor of return to sports. This study aimed to clarify the relationship between kinesiophobia and knee function 6 months after anterior cruciate ligament reconstruction when the patient intends to return to sports. [Participants and Methods] A total of 66 patients who underwent primary anterior cruciate ligament reconstruction (mean age 17.3 ± 2.6 years, 17 males and 49 females, Tegner activity score ≥7) were included in the study. The 11-item version of Tampa scale of kinesiophobia was used to evaluate kinesiophobia 6 months postoperatively. Knee function was evaluated with knee extension muscle strength, tibial anterior displacement, heel buttock distance, heel height difference, anterior knee pain score, and single-leg hop test. The relationship between Tampa scale of kinesiophobia, patient characteristics, and knee function was investigated. [Results] A low Anterior knee pain score and low single-leg hop test, male gender, and age were significant factors associated with kinesiophobia. [Conclusion] Kinesiophobia was associated with a low anterior knee pain score and low single-leg hop test 6 months after anterior cruciate ligament reconstruction. Patients with a low single-leg hop test score or severe pain may need rehabilitation to reduce kinesiophobia.

A convenient method for assessing steady-state carrier density and lifetime in solar cell materials using pulse excitation measurements.

We describe the relation of the carrier lifetime of a light-absorber material determined with pulse-excitation time-resolved techniques to the steady-state carrier density and lifetime in a solar cell under continuous-wave excitation. Our approach constitutes a simple experimental examination of the excitation-fluence-dependent carrier lifetime of absorber materials. It provides the steady-state carrier density and lifetime under 1-sun solar illumination for metal halide perovskite solar cells. The determination of the steady-state carrier responses allows the clarification of optical and photovoltaic properties under 1-sun illumination and thus the identification of loss mechanisms in device performance. Model calculations are also provided to show how the carrier lifetime governs the luminescence quantum yields and open-circuit voltages. The calculations quantify a scaling law between a monomolecular recombination lifetime and an open-circuit voltage as a result of a combination of two density-dependent effects.

Luminescence Fine Structures in Single Lead Halide Perovskite Nanocrystals: Size Dependence of the Exciton-Phonon Coupling.

Lead halide perovskite nanocrystals (NCs) have superior photoluminescence (PL) properties, such as high PL quantum yields and wide PL wavelength tunability, for optoelectronic applications. Here, we report the PL spectra of single formamidinium lead halide perovskite FAPbX3 (X = Br, I) NCs examined by single-dot spectroscopy at low temperature. We found four PL peaks in the low-energy region below the strong exciton PL peak that originate from two longitudinal-optical (LO) phonon replicas of the exciton PL, biexcitons, and charged excitons (trions). The binding energies of the biexcitons and trions become larger as the NCs decrease in size. The LO phonon energies show no size dependence, but the Huang-Rhys factors, which reflect the strength of the exciton-phonon coupling, become larger for smaller NCs. Our findings provide important insights into the exciton properties of perovskite NCs.

LiNbO3 -Type Polar Antiferromagnet InVO3 Synthesized under High-Pressure Conditions.

The ambient pressure cation disordered InVO3 bixbyite has been predicted to form a GdFeO3 -type perovskite phase under high pressure and high temperature. Contrary to the expectation, InVO3 was found to crystallize in the polar LiNbO3 -type structure with a calculated spontaneous polarization as large as 74 µC cm-2 . Antiferromagnetic coupling of V3+ magnetic moments and a cooperative magnetic ground state below about 10 K coupled with a polar structure suggest an intriguing ground state of the novel LiNbO3 -type high-pressure InVO3 structure.

Evaluation of the tissue thickness of the supraspinatus and biceps long head tendons using ultrasound among elderly patients with unilateral adhesive capsulitis in the freezing phase.

[Purpose] This study aimed to clarify the changes in the tissue thickness of the abnormal supraspinatus and biceps long-head tendons among elderly patients to select the treatment targets and evaluate the treatment effects in the freezing phase of adhesive capsulitis. [Participants and Methods] Thirty-two elderly patients with unilateral shoulder pain underwent ultrasound of the supraspinatus and biceps long-head tendons, pain evaluation, and orthopedic testing. Both the supraspinatus and biceps long-head tendons were classified as normal, abnormal, and other groups. Participants with negative orthopedic test results were assigned the "normal group". Participants with positive orthopedic test results and resting and night pain were assigned the "abnormal group". Differences in tissue thickness were calculated from the differences between the symptomatic and non-symptomatic sides. [Results] The thickness of the supraspinatus and biceps long-head tendons was significantly higher in the abnormal than in the normal group. [Conclusion] This study clarified the changes in tissue thickness of the abnormal supraspinatus and biceps long-head tendons among elderly patients to select the treatment targets and assess the treatment effects in the freezing phase of adhesive capsulitis. The study results suggest the usefulness of ultrasound for selecting the treatment targets for analgesia and assessing the treatment efficacy in cases of adhesive-capsulitis freezing phase.

Differences in gait kinetics and kinematics between patients with rotating hinge knee and cruciate-retaining prostheses: a cross-sectional study.

[Purpose] Rotating hinge knee prostheses are often used in primary total knee arthroplasty. However, the biomechanics resulting from this treatment remain unexplored. This cross-sectional study compared patient data on gait kinetics and kinematics to assess the efficacy of primary total knee arthroplasty using a rotating hinge knee or other prostheses. [Participants and Methods] Thirty-three participants were assigned to the following groups: rotating hinge knee (n=7); cruciate-retaining prosthesis (n=7); untreated osteoarthritis (n=10); and young adults as a reference group (n=9). Participant data on biomechanical and spatiotemporal parameters were analyzed. [Results] The postoperative course of the rotating hinge knee group was not significantly longer than that of the cruciate-retaining prosthesis group. The knee varus angle and adduction moment of the rotating hinge knee group were significantly smaller than those of the untreated osteoarthritis group. Gait kinetics and kinematics were not different between the rotating hinge knee and cruciate-retaining prosthesis groups. [Conclusion] Participants who had undergone primary total knee arthroplasty with a rotating hinge knee prosthesis had worse preoperative conditions and demonstrated a similar postoperative gait as those who had undergone total knee arthroplasty with other prostheses. Our findings may be used to tailor rehabilitation programs for participants who have undergone total knee arthroplasty with a rotating hinge knee implant.

The Hybrid Neurosurgeon: The Japanese Experience.

OBJECTIVE: In Japan, hybrid neurosurgeons who perform both open surgical clipping as well as endovascular embolization for the treatment of intracranial aneurysms are common. Although many Japanese neurosurgeons can perform surgical clipping of middle cerebral artery aneurysms or internal carotid artery-posterior communicating artery aneurysms and coil embolization of cerebral aneurysms using simple techniques-only a limited number of neurosurgeons are able to perform surgical clipping and endovascular procedures for anterior communicating artery aneurysms, paraclinoid, or posterior circulation aneurysms using both treatment modalities equally and safely. MATERIALS AND METHODS: The senior author's personal experience of more than 500 cases each of surgical clipping and endovascular embolization over the past 25 years included 110 cases of basilar tip aneurysms and 104 cases of paraclinoid internal carotid artery (ICA) aneurysms. RESULTS: The safety and efficacy of both treatments appears to be the same, while the durability of surgical clipping is superior to that of endovascular embolization. Among the 110 basilar tip aneurysms, 18 patients were treated by surgical clipping and 94 were treated by endovascular embolization. The initial results of endovascular therapy seemed to be better than those of surgical clipping, although the rate of retreatment was higher. Among the 104 cases of paraclinoid ICA aneurysm, 23 patients were treated by surgical clipping and 81 were treated by endovascular embolization. The results of both treatments seemed to be same, while surgical clipping had apparently good long-term durability. Over the past 15 years, the frequency of surgical clipping for basilar tip aneurysms has decreased, and the procedure may eventually be abandoned for this type of aneurysm. However, surgical clipping still offers several advantages in the treatment of paraclinoid aneurysms. CONCLUSIONS: Hybrid neurosurgeons can make reasonable decisions concerning the choice of treatment for cerebral aneurysms, as they perform both treatments and understand the benefits and drawbacks of each modality.

Effect of A-Site Cation on Photoluminescence Spectra of Single Lead Bromide Perovskite Nanocrystals.

Lead halide perovskite (APbX3) nanocrystals exhibit photoluminescence (PL) with both wide wavelength tunability and high quantum efficiency. While the Pb-X6 octahedra mainly determines the near-band-edge optical properties and the A-site cation affects the structural stability, the role of the A-site cation in determining the optical properties is still unclear. Here, we report the PL properties of three types of lead bromide perovskite APbBr3 nanocrystals with different cations [A = HC(NH2)2+, CH3NH3+, and Cs+], as revealed by single-dot spectroscopy, and discuss the influence of the A-site cation on the PL spectrum. The nanocrystal size dependences of the PL energy and lifetime show no large variation with the species of the A-site cation. We find that the size of the A-site cation determines the coupling strength between electrons and longitudinal-optical phonons in the nanocrystal and thus affects the PL spectral shape, especially the low-energy tail.

Relationship between muscle echo intensity on ultrasound and isokinetic strength of the three superficial quadriceps femoris muscles in healthy young adults.

[Purpose] The purpose of this study was to clarify the relationship between muscle echo intensity measured with ultrasound and the isokinetic strength of each of the three superficial quadriceps femoris muscles in healthy young adults. [Participants and Methods] We measured the echo intensity of the three superficial muscles of the quadriceps femoris in 25 healthy adults (10 males and 15 females; mean age, 22.3 years) using ultrasound. Moreover, we obtained the maximum force during isokinetic knee extension at 60°/s using an isokinetic dynamometer. [Results] In males and females, a significant negative correlation between echo intensity and muscle strength was found in the VM (r=-0.65 and r=-0.63, respectively). [Conclusion] In both males and females, only the muscle echo intensity of the vastus medialis was found to have a negative correlation with the maximum force during isokinetic knee extension at 60°/s. Our data lay the foundation for simplifying and rationally performing the measurement of muscle echo intensity of the quadriceps femoris. And it would therefore be sufficient to only measure the VM to clarify a relationship between EI and maximum isokinetic force in the quadriceps.

Phonon, thermal, and thermo-optical properties of halide perovskites.

Metal halide perovskites are semiconductors with many fascinating characteristics and their widespread use in optoelectronic devices has been expected. High-quality thin films and single crystals can be fabricated by simple chemical solution processes and their fundamental electrical, optical, and thermal properties can be changed significantly by compositional substitution, in particular halogen ions. In this perspective, we provide an overview of phonon and thermal properties of metal halide perovskites, which play a decisive role in determining device performance. After a brief introduction to fundamental material properties, longitudinal-optical phonons and unusual thermal properties of metal halide perovskites are discussed. Remarkably, they possess very low thermal conductivities and very large thermal expansion coefficients despite their crystalline nature. In line with these discussions, we present optical properties governed by the strong electron-phonon interactions and the unusual thermal properties. By showing their unique thermo-optic responses and novel application examples, we highlight some aspects of the unusual thermal properties.

Effect of setup error in the single-isocenter technique on stereotactic radiosurgery for multiple brain metastases.

In conventional stereotactic radiosurgery (SRS), treatment of multiple brain metastases using multiple isocenters is time-consuming resulting in long dose delivery times for patients. A single-isocenter technique has been developed which enables the simultaneous irradiation of multiple targets at one isocenter. This technique requires accurate positioning of the patient to ensure optimal dose coverage. We evaluated the effect of six degrees of freedom (6DoF) setup errors in patient setups on SRS dose distributions for multiple brain metastases using a single-isocenter technique. We used simulated spherical gross tumor volumes (GTVs) with diameters ranging from 1.0 to 3.0 cm. The distance from the isocenter to the target's center was varied from 0 to 15 cm. We created dose distributions so that each target was entirely covered by 100% of the prescribed dose. The target's position vectors were rotated from 0°-2.0° and translated from 0-1.0 mm with respect to the three axes in space. The reduction in dose coverage for the targets for each setup error was calculated and compared with zero setup error. The calculated margins for the GTV necessary to satisfy the tolerance values for loss of GTV coverage of 3% to 10% were defined as coverage-based margins. In addition, the maximum isocenter to target distance for different 6DoF setup errors was calculated to satisfy the tolerance values. The dose coverage reduction and coverage-based margins increased as the target diameter decreased, and the distance and 6DoF setup error increased. An increase in setup error when a single-isocenter technique is used may increase the risk of missing the tumor; this risk increases with increasing distance from the isocenter and decreasing tumor size.

The immediate effect of the Honda Walking Assist Device on foot and ankle function in hemiplegic stroke patients.

[Purpose] We evaluated the reliability of the measurement function of the Honda Walking Assist Device and investigated the effect of the device on walking improvements, and foot and ankle function, in hemiplegic stroke patients. [Participants and Methods] We recruited 16 hemiplegic stroke patients who performed 10-meter walk tests, twice without assistance and once with device assistance. Based on the rate of change of velocity, we divided the participants into two groups and compared the walking parameters, the toe grip strength, the cross tests, and the maximum step width. Two examiners assessed the 10-meter walk test results, and the authors calculated the intraclass correlation coefficients for walking speed, stride length, cadence, flexion, extension, and scissor angles. [Results] The intraclass correlation coefficients were greater than 0.70 for all the walking parameters we measured. The device increased hip joint movement but did not alter the maximum walking speed of the stroke patients. The patients in the group with a greater change in velocity displayed lower toe grip strength and decreased maximum step width and used orthoses more commonly. [Conclusion] The walking measurement function of the device was reliable. The immediate effect of the device in stroke patients may be influenced by the level of paralysis and the presence of an orthosis.