Dependent Changes Research Articles

Cyclometalated Iridium(III) Complex with Substituted Benzimidazole: pH Directed Organelle-Specific Localization Within Lysosome.

We report the synthesis and pH dependent emission spectral behaviour of four emissive iridium(III) complexes (Ir1-Ir4) with two isomeric pairs of bis-trifluoromethyl appended benzimidazole ligands. The imidazolyl hydrogen(N-H) has been replaced by phenyl groups (N-Ph) in two ligands to understand the impact of hydrogen bonding on the photophysical properties of the complexes and it indeed plays interesting role in the charge-transfer dynamics. The pH dependent electronic spectral change is observed for two of the complexes. The enhancement of emission intensity is observed at different wavelength for pH<7 and pH>7 for Ir1 and Ir3. The emission sensing of biogenic amines with pka values ranging from 5.80-9.74 is reported along with cellular imaging. The complex Ir1 specifically localizes within lysosome (pH=4.5-5) and thus image this organelle with great precision. The detail electronic spectra and electrochemical behaviour were reported here along with TDDFT results.

Infinitely Rugged Intra-Cage Potential Energy Landscape in Metallic Glasses Caused by Many-Body Interaction

The absence of translational symmetry in glassy materials poses a significant challenge in establishing effective structure-property relationships in real space. Consequently, the potential energy landscape (PEL) in phase space is widely utilized to comprehend the complex phenomena in glasses. The classical PEL features a two-scale profile comprising mega-basins and sub-basins, corresponding to α-relaxations (e.g. glass transition) and β-relaxations (e.g. local cage-breaking atomic rearrangements), respectively. Recent studies, however, reveal that sub-basins are not smooth and contain finer structures, the origins of which remain elusive. Here we probe the smoothness of sub-basin bottoms in glasses’ PEL by introducing small intra-cage cyclic loading and then measuring the net changes in atomic-level stresses. Compared to glasses with pair interaction, glasses with many-body interaction exhibit orders-of-magnitude larger and loading dependent stress changes even before the first cage-breaking event takes place, which reflect much more feature-rich sub-basins. We further demonstrate this stark contrast stems from the spatial distribution of individual atom’s constraining force field. Specifically, at vanishing perturbations, many-body interactions disrupt the positive-definite synchrony in energy variations of the perturbed atom and the whole system, causing inherently less confined atomic responses and infinitely rugged sub-basins. The implications of these findings for the selective addition or removal of fine structures in the PEL and the subsequent tuning of glassy materials’ responses to external stimuli are also explored.

An assessment of the seasonally dependent biophysical mechanism and dynamic land use change: A Research Effort from Emerging Urban Agglomeration of West Bengal

The behavior of the biophysical components needs to be closely observed while taking seasonal perspectives into account. This study focuses on seasonal analysis of biophysical components and dynamics of land use changes. This study examines the spatiotemporal seasonal variation among land surface temperature (LST), NDVI, and NDWI, with a focus on the two main sub-tropical climatic seasons summer and winter. We use correlation and regression analysis to assess the season-wise relationship between LST and biophysical indices with the help of grouped marginal plots. The comparison analyses of the biophysical components and land use change for a longer period from 1991-2021 with their matrix was undertaken in five urban agglomerations (UA) like Asansol, Siliguri, Kolkata, English Bazar and Kharagpur. The maximum likelihood classification technique was used to categorize multi-temporal Landsat images for each of the five growing UA in West Bengal. The most intriguing finding is that in all UAs, from 1991 to 2021, built-up area increased to become the predominant land. Thus, the vegetation and agricultural land are in danger in every location of West Bengal, whether it is plain or hilly, because of the land's gradual conversion to concrete or built-up areas over time. Additionally, the result shows that in summer and winter seasons, LST was observed growth due to the rapid urban built-up area expansion. It is also found that LST and NDVI have a close negative relationship, but LST and NDWI do not have any perfect relationship. Therefore, to lessen the warming effect of urban microclimates, policymakers should be concerned about future urban expansion that is both horizontal and vertical. An appropriate strategy for environmentally friendly construction, green buildings, and cool roof technologies should be developed.

Sitting foot: posture dependent changes of volume, edema and perfusion of the foot. A prospective interventional study with 27 volunteers

BackgroundSitting is known to be bad for your cardiovascular health. We furthermore hypothesized that sitting posture will reduce perfusion of the foot and increase edema, possibly predisposing to disease like osteochondritis.MethodsWe included 27 healthy volunteers and performed MRI measurements including arterial spin labelling (ASL) and intravoxel incoherent motion (IVIM) perfusion as well as short tau inversion recovery (STIR) edema measurement and 3D volumetry. After randomization, the elevation of one foot during the day was used as an intervention.ResultsIntra- and interrater variability was 1–6%. ASL perfusion measurement was hindered by artifacts. IVIM perfusion showed no significant changes during supine measurements. Volumetry could demonstrate a highly significant (p = 0.00005) volume increase, while the intervention led to a significant (p = 0.0076) volume decrease during the day. However, the water content in STIR remained unchanged and the normalized (quotient bone/muscle) edema was reduced on the control side (p = 0.006) and increased on the intervention side (p = 0.01).ConclusionsSitting all day leads to swelling of the healthy foot. Compensation in healthy subjects seems to prevent lasting perfusion changes or edema evolution in the bone despite an increase of muscle signal and volume increase. Thus, the etiology of osteochondritis needs further studies.

Mitigation and Optimization of Induced Seismicity Using Physics‐Based Forecasting

AbstractFluid injection can induce seismicity by altering stresses on pre‐existing faults. Here, we investigate minimizing induced earthquake potential by optimizing injection operations in a physics‐based forecasting framework. We built a 3D finite element model of the poroelastic crust for the Raton Basin, Central US, and used it to estimate time dependent Coulomb stress changes due to 25 years of wastewater injection in the region. Our finite element model is complemented by a statistical analysis of the seismogenic index (SI), a proxy for critically stressed faults affected by variations in the pore pressure. Forecasts of seismicity rate from our hybrid physics‐based statistical model suggest that induced seismicity in the Raton Basin, from 2001 to 2022, is still driven by wastewater injection despite declining injection rates since 2011. Our model suggests that pore pressure diffusion is the dominant cause of Coulomb stress changes at seismogenic depth, with poroelastic stress changes contributing about 5% to the driving force. Linear programming optimization for the Raton Basin reveals that it is feasible to reduce earthquake potential for a given amount of injected fluid (safety objective) or maximize fluid injection for a prescribed earthquake potential (economic objective). The optimization tends to spread out high‐rate injectors and shift them to regions of lower SI. The framework has practical importance as a tool to manage injection rate per unit field area to reduce induced earthquake potential. Our optimization framework is both flexible and adaptable to mitigate induced earthquake potential in other regions and for other types of subsurface fluid injection.

Dose and time dependent morphodynamic changes in the ovary of nano-nickel treated rats A SEM study

AimsPresent study demonstrates dose and time dependent effects of NiONPs (<30 nm) on the ovaries of Wistar rat. MethodsFemale rats were gavaged NiONPs or NiOMPs (5 mg/kg b.w.) for 24 h, 15 days and 30 days, euthanized and ovaries thus removed were analyzed for nickel bioaconcentration and processed for scanning electron microscopy. Serum samples were analyzed to compare the effects of nickel nano & microparticles on progesterone and estradiol values. ResultsResults confirmed the bioaccumulation of Ni in ovarian tissue. Its concentration was higher in NiONPs treated rats than NiOMPs treated rats. Progesterone level increased whereas estradiol values decreased in NiONPs and NiOMPs treated rats. SEM results also exhibited dose dependent effects on the morphology of corpoluteal complex. The structural changes varied from formation of blebs to distorted microvilli and germinal epithelium. ConclusionIt is hypothesized that NiONPs/NiOMPs are biodegraded into smaller fragments that conjugate with amino acids and or alter downstream signaling pathways, generate ROS and modulate protein structure activity relationships. Finally, these processes manifest into morphological alterations in the ovary. Biopersistence of nickel in female reproductive system may compromise with fertility and reproductive performance of exposed population.

Time dependent changes in protein expression induced by intermittent theta burst stimulation in a cell line

BackgroundIntermittent Theta Burst Stimulation (iTBS), a non-invasive brain stimulation technique, is recognized for its ability to modulate cortical neuronal activity. However, its effects over time and the dynamics following stimulation are less well understood. Understanding the temporal dynamics of iTBS effects is essential for optimizing the timing and frequency of stimulation in therapeutic applications.ObjectiveThis study investigated the temporal changes in protein expression induced by iTBS in Neuro-2a cells.MethodsWe analyzed protein expression in retinoic acid-differentiated Neuro-2a cells at multiple time points — 0.5, 3, 6, 12, and 24 hours post-iTBS — using Western blot and immunocytochemistry techniques.ResultsOur findings reveal a significant early increase in neurotransmitter receptor subunits, neurotrophic factors, and cytoskeletal proteins within the first 0.5 hour following iTBS. Notably, proteins such as mGLuR1, NMDAR1, GABBR2, and β-tubulin III showed substantial increase in expression. However, the effects of iTBS on protein expression was not sustained at later timepoints.ConclusionOur results suggest that iTBS can transiently alter the expression of specific proteins in Neuro-2a cells. Future research should investigate the potential benefits of repeated stimulations within the early time window to refine iTBS interventions, potentially expanding their research and clinical applications.

Temperature dependent effect of nano-scale phase change materials on fresh and hardened cement based mortar

One of the smart and innovative materials used to produce environmentally friendly energy-saving concrete is temperature dependent phase change (PCM) materials. In this study, the fresh and hardened concrete properties of the mortars including PCM in different ratios (0%, 2.5%, 5%) were investigated experimentally. Rheological properties such as slump-flow, specific viscosity, and yield stress tests were determined at different temperatures (from 20 to 50 °C). Time-dependent physical, mechanical, and thermal properties such as ultrasound pulse velocity (UPV), electrical resistivity, dynamic modulus of elasticity, compressive and flexural strength, thermogravimetric (TGA), and thermal conductivity tests were carried out. According to the experimental findings, the workability and hardened properties of mortars were decreased by using PCM. However, the rheological properties of fresh mortar change depending on temperature due to PCM absorbing the heat. Therefore, the fresh properties of mortar with PCM can be controlled by temperature. It was also found that the phase change of mortars with PCM can be obtained by measuring the electrical or UPV tests at different temperatures.

Forest Change Mapping using Multi-Source Satellite SAR, Optical, and LiDAR Remote Sensing Data

Abstract. This study highlights the efficacy of leveraging multi-source satellite remote sensing for precise and dependable forest change mapping. Forests play a crucial role as carbon reservoirs and are indispensable components of the global carbon and water cycle, providing essential ecosystem services. Despite their significance, forests face deforestation, diseases, and climate change threats. Recent satellite remote sensing technology advancements have facilitated accurate, persistent, and large-scale forest dynamics monitoring. New generation satellite LiDAR systems, such as GEDI and ICESat-2, offer frequent and global height information at high spatial resolutions. This research presents a processing framework for mapping forest changes by integrating SAR and optical features from Sentinel-1 and Sentinel-2 imagery with canopy heights derived from GEDI and ICESat-2 datasets. Multiple experiments and analyses were conducted in two study areas. The findings underscore the significant impact of incorporating canopy height information in enhancing the accuracy of forest change mapping, resulting in a 15% improvement in precision and a 13% enhancement in F1-score in the experimental setups. Furthermore, the developed model exhibits increased reliability and confidence in identifying correctly changed and unchanged areas while being less confident in incorrect predictions.

Effect of colloidal magnetite (Fe3O4) nanoparticles on the electrical characteristics of the azolectin bilayer in a static inhomogeneous magnetic field

This work is devoted to the study of the combined effects of applied magnetic field and MNPs on the electrical characteristics of bilayer lipid membranes. We present results of the study of electrical parameters of azolectin membranes in a static inhomogeneous magnetic field at the one-sided addition of positively charged quasi-spherical superparamagnetic magnetite nanoparticles with a diameter of about 4 nm. The magnet was located at different distances from the membrane, and the magnetic field attracted the nanoparticles to the membrane surface with different strengths. We observed three pronounced effects that depended on the external magnetic field. Firstly, after addition of nanoparticles in a magnetic field, the conductance of the membranes increased. A smooth increase in conductance was accompanied in some cases by the appearance of current jumps, which can be associated with the formation of through pores with a radius of no more than 1 nm. The conductance increased with increasing magnetic field gradient. Secondly, at zero command voltage, a negative current through the membrane was observed. Although our experiments did not allow us to unambiguously determine which particles create this current, we believe that this current is associated with the penetration of particles through the membrane. This effect intensified with increasing magnetic field gradient. Thirdly, we observed a sharp change in the nonlinear dependence of capacitance on voltage associated both with the change in the surface potential of the azolectin membrane and with the effect of MNP binding to the membrane surface on the apparent membrane capacitance.

Changes in the longitude polarization dependence of Jupiter's moon Io as evidence of the long-term variability of its volcanic activity

The aim of the work was to investigate the longitude (orbital) dependence of the polarization of Jupiter's moon Io and compare results of our study with what is reported in the literature. We used our published observations and supplemented them with new measurements carried out with the polarimeters mounted on the 2.6 m Shajn telescope of the Crimean Astrophysical Observatory and the 2 m telescope of the Peak Terskol Observatory in the UBVRI bands at phase angles between 10° and 12° in August 2023 – February 2024. We have determined that amplitude of the orbital polarization in the V band does not exceed ≈0.1 %. It is the deepest −0.17 ± 0.03 % at L ≈ 270° and the shallowest −0.07 ± 0.03 % near L ≈ 130°. These parameters differ markedly from that obtained by Zellner and Gradie (1975), which found that the orbital polarization variations from 0.4 to 0.5 % for α > 10°, and the negative branch is the deepest near L = 160° and the shallowest near L = 300°. These differences may be a consequence of changes in the reflective properties of the local areas of Io's surface due to long-term changes in Io's local or global volcanic activity.

Metabolomic analyses during chayote (Sechium edule var. virens levis) seed germination under the influence of growth regulators

The fruit of chayote (Sechium edule) has a recalcitrant seed, as a consequence, viviparism (seed germination inside the fruit) occurs in the first 13 days after harvest. However, at the moment no phytohormone–dependent metabolic changes have been described that would allow us to understand the hormonal relationship during germination. Untargeted and targeted metabolomic analyses were performed on chayote seed treated with plant growth regulators, evaluated in fruits at 7 and 10 days after harvest. Exogenous application of 2–chloroethylphosphonic acid (ethylene releaser) and gibberellic acid3 accelerated germination and viviparism, while auxins and abscisic acid delayed them. Metabolic pathways and possible key metabolites regulating germination were identified, including ethylene, gibberellins, auxins and abscisic acid. This study suggests a likely hormone interaction model during chayote seed germination.

A low-cost electronic and optical system for magnetic hyperthermia experimental studies

Magnetic hyperthermia is an alternative to treatments such as chemotherapy and radiotherapy that employs the heat generated by magnetic nanoparticles under the influence of a magnetic field to kill cancer cells while ideally causing no harm to healthy tissues. A low-cost magnetic hyperthermia investigation platform with commercially available and easy-to-assemble parts was presented to provide and expand research in this area for a larger scientific community. The magnetic hyperthermia measurement system consists of three main parts: a designed thermally insulated sample holder, a commercial 88 kHz magnetic induction heater, and a custom-built fiber optic based refractometer as temperature sensor. The system was tested with commercial EFH-1 magnetic fluids. Time dependent temperature changes were measured for applied magnetic fields of 3.5 kA/m, 4.8 kA/m, and 6.0 kA/m. The corresponding specific loss power values were calculated as 0.28 W/g, 0.51 W/g, and 0.79 W/g, respectively. Intrinsic loss power of commercial ferrofluid was determined as 0.25 ± 0.01 nHm2/kg, found to be comparable to the results of specialized commercial magnetic hyperthermia systems. The results show that the system can easily be used for hyperthermia demonstrations for educational purposes as well as in convenient scientific research with proper calibration.

Loss of collagen content is localized near cartilage lesions on the day of injurious loading and intensified on day 12.

Joint injury can lead to articular cartilage damage, excessive inflammation, and post-traumatic osteoarthritis (PTOA). Collagen is an essential component for cartilage function, yet current literature has limited understanding of how biochemical and biomechanical factors contribute to collagen loss in injured cartilage. Our aim was to investigate spatially dependent changes in collagen content and collagen integrity of injured cartilage, with an explant model of early-stage PTOA. We subjected calf knee cartilage explants to combinations of injurious loading (INJ), interleukin-1α-challenge (IL) and physiological cyclic loading (CL). Using Fourier transform infrared microspectroscopy, collagen content (Amide I band) and collagen integrity (Amide II/1338 cm-1 ratio) were estimated on days 0 and 12 post-injury. We found that INJ led to lower collagen content near lesions compared to intact regions on day 0 (p < 0.001). On day 12, near-lesion collagen content was lower compared to day 0 (p < 0.05). Additionally, on day 12, INJ, IL, and INJ + IL groups exhibited lower collagen content along most of tissue depth compared to free-swelling control group (p < 0.05). CL groups showed higher collagen content along most of tissue depth compared to corresponding groups without CL (p < 0.05). Immunohistochemical analysis revealed higher MMP-1 and MMP-3 staining intensities localized within cell lacunae in INJ group compared to CTRL group on day 0. Our results suggest that INJ causes rapid loss of collagen content near lesions, which is intensified on day 12. Additionally, CL could mitigate the loss of collagen content at intact regions after 12 days.

Ultrafast and Coherent Dynamics in a Solvent Switchable "Pink Box" Perylene Diimide Dimer.

Perylene diimide (PDI) dimers and higher aggregates are key components in organic molecular photonics and photovoltaic devices, supporting singlet fission and symmetry breaking charge separation. Detailed understanding of their excited states is thus important. This has proven challenging because interchromophoric coupling is a strong function of dimer architecture. Recently, a macrocyclic PDI dimer was reported in which excitonic coupling could be turned on and off simply by changing the solvent. This presents a useful case where coupling is modified without synthetic changes to tune supramolecular structure. Here we present a detailed study of solvent dependent excited state dynamics in this dimer by means of coherent multidimensional spectroscopy. Spectral analysis resolves the different coupling strengths, which are consistent with solvent dependent changes in dimer conformation. The strongly coupled conformer forms an excimer within 300 fs. The low-frequency Raman active modes recovered from two-dimensional electronic spectra reveal frequencies characteristic of exciton coupling. These are assigned to modes modulating the coupling from the corresponding DFT calculations. Further analysis reveals a time dependent frequency during excimer formation. Analysis of two-dimensional "beatmaps" reveals features in the coupled dimer which are not predicted by the displaced harmonic oscillator model and are assigned to vibronic coupling.

From sectoral policy change to cross-sectoral (dis)integration? A longitudinal analysis of the EU's forest and rural development policy

Policy integration (PI) is critical to address cross-cutting challenges like climate change and biodiversity loss holistically. In the European Union, forests are confronting increasingly adverse climatic conditions and numerous stressors that impact their biodiversity. Political efforts to counteract these trends are mainly channeled through funding from the rural development policy as a pivotal part of the Common Agricultural Policy (CAP). In contrast, forest policy is hardly institutionalized at EU level. This study employs process tracing using 65 EU forest and rural development policy documents, including legal acts, preparatory documents, communications, related working documents and evaluation reports, predominantly produced over the last 25 years. By doing this, it examines the development of sectoral policy changes over time and their implications for the cross-sectoral integration of EU forest policy into rural development policy as part of agricultural policy at EU level. Results suggest that the adoption of the EU Forest Strategy for 2030 represented a provisional paradigm shift in EU forest policy. This shift is characterized by a substantial reprioritization of policy objectives, transitioning from an emphasis on economic aspects to a more climate- and biodiversity-centric approach, alterations in supported policy instruments and the introduction of various new regulatory instruments. On the other hand, the CAP and its rural development policy remain characterized by a path dependent incremental change and the latest reforms hardly reflect ambitious forest policy objectives both from budgetary and content perspectives. The findings suggest that the latest seemingly decoupled developments within both policy areas have led to an emergence of forest policy fragmentation at the EU level.

Development of a General Composite Scale (GENCOMS) for Progressive Neurodegenerative Diseases and Implications for the Assessment of Disease-Modifying Therapies.

The reliable assessment of treatment outcomes for disease-modifying therapies (DMT) in neurodegenerative disease is challenging. The objective of this paper is to describe a generalized framework for developing composite scales that can be applied in diverse, degenerative conditions, termed "GENCOMS." Composite scales optimize the sensitivity for detecting clinically meaningful effects that slow disease progression. The GENCOMS method relies on robust natural history data and/or placebo arm data from DMT trials. Validated scales that are core to the disease process have been identified, and item level data obtained to standardize the response outcomes from 0 (best possible score) to 1 (worst possible score). A partial least squares regression analysis was conducted with temporal change as the dependent variable and change scores in standardized items as the explanatory variables. The derived model coefficients constitute a weighted sum of items that most effectively measure disease progression. The resultant composite scale was optimized to detect disease progression and can be examined in a range of slow or fast progressing populations. The scale can be used in studies with comparable patient populations as an endpoint optimized to measure disease progression and therefore ideally suited to assess treatment effects in DMTs. The methodology presented here provides a generalizable framework for developing composite scales in the assessment of neurodegenerative disease progression and evaluation of DMT effects. By objectively selecting and weighting items from previously validated measures based solely on their sensitivity to disease progression, this methodology allows for the creation of a more responsive measurement of clinical decline. This heightened sensitivity to clinical decline can be utilized to detect modest yet meaningful treatment effects in the early stages of neurogenerative diseases, when it is optimal to begin a DMT.

The Effect of the Season on the Time Dependent Changes in Colostrum Lactoferrin Level in Murciano-Granadina Goats in Intensive System Farming.

The aim of this research was to evaluate the effects of postpartum day and parity season on the lactoferrin (LF), immunoglobulin G (IgG), and chemical composition of Murciano-Granadina goat colostrum during the first 96 h after kidding, and the use of the Brix refractometer to estimate IgG content. A herd of 3500 intensively managed Murciano-Granadina dairy goats (45-50 kg body weight) was used. Colostrum samples were collected from days 1 to 4 postpartum in the winter, spring, summer, and autumn. The colostrum composition was assessed using an automated infrared method; the LF and IgG concentrations were measured using an ELISA, and for the Brix percentage, we used a digital refractometer. Colostrum taken on the first postpartum day showed the highest concentrations of LF, IgG, proteins and non-fat solids (NFSs). As the postpartum days progressed, a rapid decrease in the LF, IgG, protein, and NFS contents and the Brix value was observed. In contrast, the lactose content increased steadily until the fourth postpartum day (p < 0.001). The season influenced milk yield, LF, IgG, protein, fat, and somatic cell content (p < 0.05). LF contents were significantly higher in the spring season, IgG contents were higher in autumn colostrum, and fat components were higher in the winter season. The colostrum Brix value showed a positive correlation with the ELISA colostrum LF (r = 0.716, p < 0.001) and IgG (r = 0.894, p < 0.001) determination; a 20 mg IgG/mL colostrum concentration corresponded to 18 °Brix. Our results corroborate the importance of feeding colostrum to newborns on the first day after birth, not only because of its high level of IgG but also because of its greater presence of the other bioactive protein compounds such as lactoferrin.

Motor practice related changes in the sensorimotor cortices of youth with cerebral palsy.

The altered sensorimotor cortical dynamics seen in youth with cerebral palsy appear to be tightly coupled with their motor performance errors and uncharacteristic mobility. Very few investigations have used these cortical dynamics as potential biomarkers to predict the extent of the motor performance changes that might be seen after physical therapy or in the design of new therapeutic interventions that target a youth's specific neurophysiological deficits. This cohort investigation was directed at evaluating the practice dependent changes in the sensorimotor cortical oscillations exhibited by youth with cerebral palsy as a step towards addressing this gap. We used magnetoencephalography to image the changes in the cortical oscillations before and after youth with cerebral palsy (N = 25; age = 15.2 ± 4.5 years; Gross Motor Function Classification Score Levels I-III) and neurotypical controls (N = 18; age = 14.6 ± 3.1 years) practiced a knee extension isometric target-matching task. Subsequently, structural equation modelling was used to assess the multivariate relationship between changes in beta (16-22 Hz) and gamma (66-82 Hz) oscillations and the motor performance after practice. The structural equation modelling results suggested youth with cerebral palsy who had a faster reaction time after practice tended to also have a stronger peri-movement beta oscillation in the sensorimotor cortices following practicing. The stronger beta oscillations were inferred to reflect greater certainty in the selected motor plan. The models also indicated that youth with cerebral palsy who overshot the targets less and matched the targets sooner tended to have a stronger execution-related gamma response in the sensorimotor cortices after practice. This stronger gamma response may represent improve activation of the sensorimotor neural generators and/or alterations in the GABAergic interneuron inhibitory-excitatory dynamics. These novel neurophysiological results provide a window on the potential neurological changes governing the practice-related outcomes in the context of the physical therapy.

Pacing cycle length–dependent electrophysiologic changes in left atrium: Poor validity of using low-voltage area and slow conduction area under specific pacing cycle length as absolute substrates of atrial fibrillation

BackgroundPacing cycle length (PCL)–dependent changes in left atrial (LA) electrophysiologic properties have not been fully elucidated. ObjectiveWe aimed to elucidate these changes using a high-resolution mapping system. MethodsForty-eight patients underwent atrial fibrillation ablation with RHYTHMIA HDx. Paired LA maps under a baseline PCL (600 ms) and rapid PCL (300 ms) were acquired after pulmonary vein isolation under right atrial appendage pacing. The PCL-dependent change in the low-voltage area (LVA; area with <0.5 mV bipolar voltage), LA activation time (interval from first LA activation to wavefront collision at lateral wall), regional mean voltage, regional mean wave propagation velocity, and slow conduction area (area with <0.3 m/s wave propagation velocity) were quantitatively analyzed. ResultsUnder the rapid PCL, the total LVA was significantly increased (7.6 ± 9.5 cm2 vs 6.7 ± 7.6 cm2; P = .031), especially in patients with a 10 cm2 LVA on the baseline PCL map (21.5 ± 9.1 cm2 vs 18.1 ± 6.5 cm2; P = .013). The LA activation time was also prolonged (87.9 ± 16.2 ms vs 84.0 ± 14.0 ms; P < .0001). Although the rapid PCL did not decrease the regional mean voltage, it significantly decreased the regional mean wave propagation velocity and increased the slow conduction area in all measured regions. ConclusionLVA and slow conduction area can be emphasized by rapid PCL LA mapping. There may be poor validity in using these areas as absolute atrial fibrillation substrates without considering the PCL-dependent changes.