Trends Favoring an Anatomical Approach to Radiofrequency Catheter Ablation of Idiopathic Ventricular Arrhythmias Originating From the Left Ventricular Summit.

BACKGROUND: Epicardial radiofrequency catheter ablation (RFCA) of idiopathic ventricular arrhythmias (VAs) originating from the left ventricular summit (LVS) is challenging because of the anatomic barriers. On the other hand, RFCA at the endocardial sites near the earliest epicardial activation site of LVS-VAs (anatomic approach) has proven successful. The evolving trends in the approaches and outcomes of RFCA of LVS-VAs at a single center were evaluated. METHODS: We studied 88 consecutive patients with idiopathic LVS-VAs at our institute from 2009 to 2019. These patients were divided into 3 periods: 2009 to 2012 (early), 2013 to 2015 (middle), and 2016 to 2019 (recent). The data were compared among the 3 periods. RESULTS: The RFCA success rate did not significantly change from the early-to-middle period but significantly increased from the middle-to-recent period (P=0.0315). The transpericardial approach usage significantly decreased over the 3 periods. The anatomic approach usage significantly increased over the 3 periods. The use of the transpericardial approach did not affect the RFCA outcomes over the 3 periods. The success rate of the anatomic RFCA tended to increase from the early-to-middle period and significantly increased from the middle-to-recent period (P=0.0412). The number of endocardial locations where RFCA was successful increased over the 3 periods. CONCLUSIONS: Over the 10-year period, the transpericardial approach became decreasingly performed, whereas the anatomic approach became increasingly performed with a satisfactory improvement in the RFCA outcomes of LVS-VAs. The anatomic RFCA became more successful by identifying more and various endocardial locations as target sites.

Differences in lower extremity kinematics during single-leg lateral drop landing of healthy individuals, injured but asymptomatic patients, and patients with chronic ankle instability- a cross-sectional observational study.

The lower-extremity kinematics associated with forward jump landing after an ankle injury is known to differ for patients with Chronic Ankle Instability (CAI), copers (injured but asymptomatic patients), and healthy individuals. However, the differences in the lower extremity kinematics of these groups associated with a Single-leg Lateral Drop Landing (SLDL) are unknown. The purpose of this study is to characterize the lower limb and foot kinematics during SLDL in CAI patients and to compare these characteristics with those of the copers and healthy individuals. This was a cross-sectional observational study. Nineteen participants, each, were selected from the CAI, Coper, and control groups. The lower-extremity kinematics during SLDL was measured using three-dimensional motion analysis over an interval progressing from 200 ms before landing to 200 ms after landing. Either one-way ANOVA or the Kruskal-Wallis test was used to compare the attributes of the respective groups, with each parameter measured every 10 ms. The maximum values and excursions of the parameters were established over time intervals progressing from 200 ms before landing to 200 ms after landing. Significant observations were subjected to post hoc analysis. Compared to the Coper group, the CAI group exhibited significantly smaller hip adduction angles at 160 ms, ankle dorsiflexion angles in the 110-150 ms interval, and maximum ankle dorsiflexion angles after landing. Compared to the control group, the CAI group exhibited significantly smaller excursions of MH inversion/eversion after landing. Our findings confirm the necessity of focusing on the kinematics of hip adduction/abduction and plantar/dorsiflexion during SLDL in evaluating patients with ankle injuries.

Effective design of PEGylated polyion complex (PIC) nanoparticles for enhancing PIC internalisation in cells utilising block copolymer combinations with mismatched ionic chain lengths.

In nanomedicine, PEGylation of nanomaterials poses a dilemma since it inhibits their interaction with target cells and enables their retention in target tissues despite its biocompatibility and nonspecific internalisation suppression. PEGylated polypeptide-based polyion complexes (PICs) are fabricated via the self-assembly of PEGylated aniomers and homocatiomers based on electrostatic interactions. We propose that various parameters like block copolymer design and PIC domain characteristics can enhance the cell-PEGylated PIC interactions. Remarkably, the properties of the PIC domain were tuned by the matched/mismatched ionomer chain lengths, PIC domain crosslinking degree, chemical modification of cationic species after crosslinking, PIC morphologies (vesicles/micelles) and polyethylene glycol (PEG) chain lengths. Cellular internalisation of the prepared PICs was evaluated using HeLa cells. Consequently, mismatched ionomer chain lengths and vesicle morphology enhanced cell-PIC interactions, and the states of ion pairing, particularly cationic residues, affected the internalisation behaviours of PICs via acetylation or guanidinylation of amino groups on catiomers. This treatment attenuated the cell-PIC interactions, possibly because of reduced interaction of PICs with negatively charged species on the cell-surface, glycosaminoglycans. Moreover, morphology and PEG length were correlated with PIC internalisation, in which PICs with longer and denser PEG were internalised less effectively. Cell line dependency was tested using RAW 264.7 macrophage cells; PIC recognition could be maintained after capping amino groups on catiomers, indicating that the remaining anionic groups were still effectively recognised by the scavenger receptors of macrophages. Our strategy for tuning the physicochemical properties of the PEGylated PIC nanocarriers is promising for overcoming the PEG issue.

Size Dependence of Trion and Biexciton Binding Energies in Lead Halide Perovskite Nanocrystals.

Lead halide perovskite nanocrystals (NCs) have attracted much attention as light-source materials for light-emitting diodes, lasers, and quantum light emitters. The luminescence properties of perovskite NCs and the performance of NC-based light-source devices depend on trion and biexciton dynamics. Here, we examined the size dependence of trion and biexciton binding energies by conducting low-temperature single-dot spectroscopy on three different perovskite NCs: CsPbBr3, CsPbI3, and FAPbBr3. While the photoluminescence spectral widths of the all-inorganic CsPbBr3 and CsPbI3 NCs were narrow, compared with those of the organic-inorganic hybrid FAPbBr3 NCs, the binding energies of trions and biexcitons of all three samples showed similar size dependences, independent of the A-site cation and halogen. The effective-mass approximation calculations implied the importance of dynamical dielectric screening on the formation of trions and biexcitons.

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.

In Situ Thermal Cross-Linking of 9,9'-Spirobifluorene-Based Hole-Transporting Layer for Perovskite Solar Cells.

A novel 9,9'-spirobifluorene derivative bearing thermally cross-linkable vinyl groups (V1382) was developed as a hole-transporting material for perovskite solar cells (PSCs). After thermal cross-linking, a smooth and solvent-resistant three-dimensional (3D) polymeric network is formed such that orthogonal solvents are no longer needed to process subsequent layers. Copolymerizing V1382 with 4,4'-thiobisbenzenethiol (dithiol) lowers the cross-linking temperature to 103 °C via the facile thiol-ene "click" reaction. The effectiveness of the cross-linked V1382/dithiol was demonstrated both as a hole-transporting material in p-i-n and as an interlayer between the perovskite and the hole-transporting layer in n-i-p PSC devices. Both devices exhibit better power conversion efficiencies and operational stability than devices using conventional PTAA or Spiro-OMeTAD hole-transporting materials.

Spontaneous Polarization Induced Optical Responses in a Two-Dimensional Ferroelectric Halide Perovskite.

Two-dimensional (2D) halide perovskites exhibit unique structural and optical properties because large organic molecular cations distort the perovskite structure and the excitons confined in the 2D layers are stable. Here, we report the temperature dependences of the absorption spectra, second harmonic generation (SHG) intensity, and lattice constants of 2D perovskite (BA)2(EA)2Pb3I10 single crystals, where BA is n-butylammonium and EA is ethylammonium. We found that the Urbach tail of the absorption spectrum significantly changes at around 200 K and that the change is correlated with the SHG intensity and the in-plane lattice distortion. We concluded that a random distribution of spontaneous polarizations in the ferroelectric phase modifies the linewidth of the band-edge exciton transition and is the cause of the anomalous temperature dependence of the steepness parameter of the Urbach tail.

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.

Verification of Qfix Encompass™ couch modeling using the Acuros XB algorithm and HypeArc™ using a high-spatial-resolution two-dimensional diode array.

We modeled the Qfix Encompass™ immobilization system and further verified the calculated dose distribution of the AcurosXB (AXB) dose calculation algorithm using SRS MapCHECKⓇ (SRSMC) in the HyperArc™ (HA) clinical plan. An Encompass system with a StereoPHAN™ QA phantom was scanned by SOMATOM go.Sim and imported to an Eclipse™ treatment planning system to create a treatment plan for Encompass modeling. The Encompass modeling was performed in the StereoPHAN with a pinpoint ion chamber for 6 MV and 6 MV flattening filter free (6 MV FFF), and 2 × 2 cm2, 4 × 4 cm2, and 6 × 6 cm2 irradiation field sizes. The dose calculation algorithm used was AXB ver. 15.5 with a 1.0 mm calculation grid size. The Hounsfield unit (HU) values of the Encompass modeling were set to 400, -100, -200, and -300 for Encompass, and -400, -600, -700, and -800 for the Encompass base. We evaluated the dose distribution after Encompass modeling by SRSMC using gamma analysis in 12 patients. We adopted HU values of -200 for Encompass, -800 for Encompass base for 6 MV, and -200 for Encompass and -700 for Encompass. Base for 6 MV FFF was adopted as the HU values for the Encompass modeling based on the measurement results. The proposed Encompass modeling resulted in a mean pass rate evaluation >98% for both 6 MV and 6 MV FFF when the 1%/1 mm criterion was used, demonstrating that the proposed HU value can be adopted to calculate more accurate dose distributions.

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.

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.

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.

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%.

Predictors of Successful Endocardial Ablation of Epicardial Left Ventricular Summit Arrhythmias.

Endocardial catheter ablation of ventricular arrhythmias (VAs) originating from the left ventricular summit (LVS) at remote structures adjacent to the LVS may be an alternative (anatomic approach) but may not be so successful. This type of catheter ablation is successful most commonly in the left ventricular outflow tract followed by the aortic cusps and rarely in the right ventricular outflow tract. A right bundle branch block QRS morphology and anatomic distance between the earliest ventricular activation site in the coronary venous system and endocardial ablation site (<13 mm) could be predictors of a successful endocardial catheter ablation of LVS VAs.

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.

Synergistic Surface Modification of Tin-Lead Perovskite Solar Cells.

Interfaces in thin-film photovoltaics play a pivotal role in determining device efficiency and longevity. In this work, the top surface treatment of mixed tin-lead (≈1.26 eV) halide perovskite films for p-i-n solar cells is studied. Charge extraction is promoted by treating the perovskite surface with piperazine. This compound reacts with the organic cations at the perovskite surface, modifying the surface structure and tuning the interfacial energy level alignment. In addition, the combined treatment with C60 pyrrolidine tris-acid (CPTA) reduces hysteresis and leads to efficiencies up to 22.7%, with open-circuit voltage values reaching 0.90 V, ≈92% of the radiative limit for the bandgap of this material. The modified cells also show superior stability, with unencapsulated cells retaining 96% of their initial efficiency after >2000 h of storage in N2 and encapsulated cells retaining 90% efficiency after >450 h of storage in air. Intriguingly, CPTA preferentially binds to Sn2+ sites at film surface over Pb2+ due to the energetically favored exposure of the former, according to first-principles calculations. This work provides new insights into the surface chemistry of perovskite films in terms of their structural, electronic, and defect characteristics and this knowledge is used to fabricate state-of-the-art solar cells.

Techniques for Catheter Ablation of Idiopathic Ventricular Arrhythmias Originating from the Outflow Tract and Left Ventricular Summit.

Idiopathic ventricular arrhythmias (VAs) most commonly originate from the ventricular outflow tracts. Because the anatomy of this region is complex and some of those VA origins are intramural and epicardial, it may sometimes be difficult to locate the site of the VA origin. Meticulous mapping in multiple different locations such as the right and left ventricular outflow tracts, endocardial and epicardial sites, and above and below the aortic and pulmonic valves may be required to achieve successful catheter ablation of those VAs. Special ablation techniques may be considered to improve the outcome of catheter ablation of intramural and epicardial VAs.

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.

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.