Dynamic Disorder Research Articles

Temperature‐Dependent Charge‐Carrier Dynamics in Lead‐Halide Perovskites: Indications for Dynamic Disorder Dominated Scattering Mechanism

AbstractLead‐halide perovskites have emerged as a promising material class in light‐harvesting and light‐emitting applications due to their exceptional semiconductor properties. Nonetheless, crucial semiconducting properties such as the charge carrier scattering mechanism and its impact on recombination dynamics are not well studied. Here, five different lead‐halide perovskite compositions are systematically examined to determine their temperature‐dependent mobility, and the prevalent scattering mechanisms involved are identified. Dynamic disorder is proposed to be the predominant scattering mechanism at room temperature and above, as evidenced by a change in the power‐law Tm. Notably, the onset temperature for this behavior varies with the perovskite composition. Additionally, it is found that this scattering process coincides with changes in fast‐trapping behavior in MAPbI3 perovskite, which in turn alters recombination dynamics such as carrier lifetime and diffusion length. These results suggest that this scattering mechanism contributes to the defect tolerance of perovskites, providing valuable insights for further investigations.

Dynamical Disorder in the Mesophase Ferroelectric HdabcoClO4: A Machine-Learned Force Field Study.

Hybrid molecular ferroelectrics with orientationally disordered mesophases offer significant promise as lead-free alternatives to traditional inorganic ferroelectrics owing to properties such as room temperature ferroelectricity, low-energy synthesis, malleability, and potential for multiaxial polarization. The ferroelectric molecular salt HdabcoClO4 is of particular interest due to its ultrafast ferroelectric room-temperature switching. However, so far, there is limited understanding of the nature of dynamical disorder arising in these compounds. Here, we employ the neural network NeuralIL to train a machine-learned force field (MLFF) with training data generated using density functional theory. The resulting MLFF-MD simulations exhibit phase transitions and thermal expansion in line with earlier reported experimental results, for both a low-temperature phase transition coinciding with the orientational disorder of ClO4 - and the onset of rotation of both Hdabco+ and ClO4 - in a high-temperature phase transition. We also find proton transfer even in the low-temperature phase, which increases with temperature and leads to associated proton disorder as well as the onset of disorder in the direction of the hydrogen-bonded chains.

Grain and Domain Microstructure in Long Chain N-Alkane and N-Alkanol Wax Crystals.

Waxes comprise a diverse set of materials from lubricants and coatings to biological materials such as the intracuticular wax layers on plant leaves that restrict water loss to inhibit dehydration. Despite the often mixed hydrocarbon chain lengths and functional groups within waxes, they show a propensity for ordering into crystalline phases, albeit with a wealth of solid solution behavior and disorder modes that determine chemical transport and mechanical properties. Here, we reveal the microscopic structure and heterogeneity of replica leaf wax models based on the dominant wax types in the Schefflera elegantissima plant, namely C31H64 and C30H61OH and their binary mixtures. We observe defined grain microstructure in C31H64 crystals and nanoscale domains of chain-ordered lamellae within these grains. Moreover, nematic phases and dynamical disorder coexist with the domains of ordered lamellae. C30H61OH exhibits more disordered chain packing with no grain structure or lamellar domains. Binary mixtures from 0-50% C30H61OH exhibit a loss of grain structure with increasing alcohol content accompanied by increasingly nematic rather than lamellar chain packing, suggesting a partial but limited solid solution behavior. Together, these results unveil the previously unseen microstructural features governing flexibility and permeability in leaf waxes and outline an approach to microstructure analysis across agrochemicals, pharmaceuticals, and food.

Predicting Parkinson’s Disease Using Machine Learning Model

This research work discusses the steps involved in developing a machine learning program for the early detection of Parkinson's disease (PD) using a variety of clinical and behavioral data. By utilizing highlights extracted from persistent data, including engine and non-motor side effects, the demonstration employs administered learning procedures to identify patterns indicative of Parkinson's disease (PD). We assess the performance of various calculations, including back vector machines and neural systems, to determine the most effective method for accurate forecasts. The results demonstrate the model's potential to enhance early diagnosis and personalized treatment strategies for Parkinson's infection. Parkinson's disease (PD) is a dynamic neurodegenerative disorder characterized by engine side effects such as tremors, inflexibility, and bradykinesia, as well as non-motor side effects including cognitive disability and autonomic brokenness. Early and precise diagnosis is essential for effective management and treatment of the infection. In later years, machine learning (ML) has risen as an effective device in the field of therapeutic diagnostics, advertising potential changes in the early location and observation of Parkinson's malady.

Pressure-regulated rotational guests in nano-confined spaces suppress heat transport in methane hydrates

Materials with low lattice thermal conductivity are essential for various heat-related applications like thermoelectrics, and usual approaches for achieving this rely on specific crystalline structures. Here, we report a strategy for thermal conductivity reduction and regulation via guest rotational dynamics and their couplings with lattice vibrations. By applying pressure to manipulate rotational states, we find the intensified rotor-lattice couplings of compressed methane hydrate MH-III can trigger strong phonon scatterings and phonon localizations, enabling an almost three-fold suppression of thermal conductivity. Besides, the disorder in methane rotational dynamics results in anharmonic interactions and nonlinear pressure-dependent heat transport. The overall guest rotational dynamics and heat conduction changes can be flexibly regulated by the rotor-lattice coupling strength. We further underscore that this reduction mechanism can be extended to a wide range of systems with different structures. The results demonstrate a potentially universal method for reducing or controlling heat transport by developing a hybrid system with tailored molecular rotors.

Quercetin Protects against Silicon dioxide Particles-induced spleen ZBP1-Mediated PANoptosis by regulating the Nrf2/Drp1/mtDNA axis

Silicon dioxide particles (SiO2) are a widely used novel material, and SiO2 that enter the body can accumulate in the spleen and cause spleen injury. Quercetin (Que) has a strong antioxidant activity and can also regulate and improve immune function, but whether Que can improve SiO2-induced spleen injury and its underlying mechanism remain to be explored. Herein, we established a C57BL/6 mice model with SiO2 exposure (10 mg/kg) and treated with Que (25 mg/kg). We also cultured CTLL-2 cells for in vitro experiments. Studies in vivo and in vitro showed that SiO2 exposure caused oxidative stress and mitochondrial dynamics disorder, which led to decrease of mitochondrial membrane potential (ΔΨm) and mitochondrial DNA (mtDNA) leakage. mtDNA was recognized by Z-DNA binding protein 1 (ZBP1) in the cytoplasm and increased the expression of ZBP1. This process further promoted the assembly of the ZBP1-mediated PANoptosome, which subsequently induced PANoptosis. Interestingly, supplementation with Que significantly reversed these changes. Specifically, Que mitigated spleen ZBP-1 mediated PANoptosis through preventing mtDNA leakage via regulating nuclear factor erythroid 2-related factor 2/reactive oxygen species/dynamin-related protein 1 (Nrf2/ROS/Drp1) axis. This study enriches the understanding of the toxicological mechanisms of SiO2 and provides evidence for the protective effects of Que against SiO2-induced splenic toxicity.

The Effect of Towel Toe Curl Exercise and Tibialis Posterior Strengthening on Dynamic Balance of Flatfoot Patients at SD Negeri 104242 Lubuk Pakam

Background: Improper use of the foot can cause problems when walking and even endanger a person's health. The arch of the foot helps withstand impact pressure and provides stability when standing or walking. Flatfoot is a deformity related to the foot, such as medial longitudinal arch disorders of the foot, valgus deformity of the heel, and forefoot abduction. The exercise methods that can be given to overcome flatfoot are Towel toe curl exercise and tibialis posterior strengthening. Purpose: to improve foot function by strengthening the intrinsic muscles of the foot. While tibialis posterior strengthening exercise is to strengthen the tibialis posterior muscle, which is part of the extrinsic muscle. Research method: This type of research is quantitative with a one group pre-test and post-test design. Data analysis using paired sample t-test. The sample of this study were children at SD Negeri 104242 Lubuk Pakam who suffered from flatfoot with a total of 22 samples. The intervention given was towel toe curl and tibialis posterior strengthening 3 times a week for 4 weeks with a total of 12 actions. Before the dynamic balance intervention, respondents were measured first (pretest) with the Y Balance Test (YBT) and re-measured after the intervention (Posttest). Results and discussion: The results of the paired sample t-test obtained a significant value (p) of 0.000, greater than the alpha value (a) (0.000 <0.05), meaning that there is a significant effect of towel toe curl exercises and tibialis posterior strengthening on improving dynamic balance in flatfoot children. Conclusion: Based on the results of the study, it can be concluded that towel toe curl exercises and tibialis posterior strengthening can be one of the training methods that can be applied to overcome dynamic balance disorders in flatfoot sufferers

Suppressing Static and Dynamic Disorder for High-Efficiency and Stable Thick-Film Organic Solar Cells via Synergistic Dilution Strategy.

Developing stable and highly efficient thick-film organic solar cells (OSCs) is crucial for the large-scale commercial application of organic photovoltaics. A novel synergistic dilution strategy to address this issue, using Polymethyl Methacrylate (PMMA) -modified zinc oxide (ZnO) as the interfacial layer, is introduced. This strategy effectively mitigates oxygen defects in ZnO while also regulating the self-assembly process of the active layer to achieve an ordered distribution of donors and acceptors. In synergistic diluted devices, the dynamic disorder is reduced owing to the suppression of electron-phonon coupling, while the static disorder is suppressed by improved molecular stacking and enhanced intermolecular interactions. Consequently, the 300nm PM6:L8-BO device post-synergistic dilution manifests a marked enhancement in device performance, achieving a photovoltaic power conversion efficiency (PCE) >17% with excellent thermal stability. A typical ternary system is selected to explore the general applicability of synergistic dilution strategy, the PCE has been enhanced significantly from 17.89% to 18.72%, which falls within the range of the highest values among inverted single junction OSCs. As a practical application that depends on the pivotal synergy between high efficiency and stability, this approach paves the way for large-scale implementation of OSCs and ensures cost-effectiveness.

Fluctuation Phenomena in Single Injection Solid State Spherical Devices under Amorphous Regime

Fluctuation effects in single injection solid-state sphere devices working in the amorphous regime are an interesting area of study that has effects on the stability and performance of electronic devices. This study looks into how changes in these devices' working features affect them, focused on how they act when they are in a fluid state. Solid-state sphere devices have unique electrical and structure properties. These properties are more noticeable in amorphous materials, where the disorder of the atoms affects how charges move and how reliable the device is. We look at the fluctuation effects that happen during single injection processes, in which carriers are brought into the device from a single source. It is called an amorphous phase because there is no long-range order. The inserted charge carriers and the disordered atomic lattice respond in a complicated way. The device's efficiency measures, like charge build up, current-voltage traits, and noise levels, change a lot because of this interaction. In order to describe these changes, our research uses both practical and theoretical methods. We use advanced measurement methods to find out about electrical reactions and noise bands, and we're also making theoretical models to figure out how the things we see happen. The results show that changes are affected by things like carrier trapping, limited states, and dynamic disorder in the amorphous material. The results of this study help us learn more about how stable and reliable single-injection solid-state sphere devices are in amorphous environments. These results could help improve the performance of amorphous materials used in many electronic and optical systems by making device designs more efficient.

The utility of MRI radiological biomarkers in determining intracranial pressure

Intracranial pressure (ICP) is a physiological parameter that conventionally requires invasive monitoring for accurate measurement. Utilising multivariate predictive models, we sought to evaluate the utility of non-invasive, widely accessible MRI biomarkers in predicting ICP and their reversibility following cerebrospinal fluid (CSF) diversion. The retrospective study included 325 adult patients with suspected CSF dynamic disorders who underwent brain MRI scans within three months of elective 24-h ICP monitoring. Five MRI biomarkers were assessed: Yuh sella grade, optic nerve vertical tortuosity (VT), optic nerve sheath distension, posterior globe flattening and optic disc protrusion (ODP). The association between individual biomarkers and 24-h ICP was examined and reversibility of each following CSF diversion was assessed. Multivariate models incorporating these radiological biomarkers were utilised to predict 24-h median intracranial pressure. All five biomarkers were significantly associated with median 24-h ICP (p < 0.0001). Using a pair-wise approach, the presence of each abnormal biomarker was significantly associated with higher median 24-h ICP (p < 0.0001). On multivariate analysis, ICP was significantly and positively associated with Yuh sella grade (p < 0.0001), VT (p < 0.0001) and ODP (p = 0.003), after accounting for age and suspected diagnosis. The Bayesian multiple linear regression model predicted 24-h median ICP with a mean absolute error of 2.71 mmHg. Following CSF diversion, we found pituitary sella grade to show significant pairwise reversibility (p < 0.001). ICP was predicted with clinically useful precision utilising a compact Bayesian model, offering an easily interpretable tool using non-invasive MRI data. Brain MRI biomarkers are anticipated to play a more significant role in the screening, triaging, and referral of patients with suspected CSF dynamic disorders.

Quantifying CSF Dynamics disruption in idiopathic normal pressure hydrocephalus using phase lag between transmantle pressure and volumetric flow rate

Background and purposeIdiopathic normal pressure hydrocephalus (iNPH) is a cerebrospinal fluid (CSF) dynamics disorder as evidenced by the delayed ascent of radiotracers over the cerebral convexity on radionuclide cisternography. However, the exact mechanism causing this disruption remains unclear. Elucidating the pathophysiology of iNPH is crucial, as it is a treatable cause of dementia. Improving the diagnosis and treatment prognosis rely on the better understanding of this disease. In this study, we calculated the pulsatile transmantle pressure and investigated the phase lag between this pressure and the volumetric CSF flow rate as a novel biomarker of CSF dynamics disruption in iNPH. Methods44 iNPH patients and 44 age- and sex-matched cognitively unimpaired (CU) control participants underwent MRI scans on a 3T Siemens scanner. Pulsatile transmantle pressure was calculated analytically and computationally using volumetric CSF flow rate, cardiac frequency, and aqueduct dimensions as inputs. CSF flow rate through the aqueduct was acquired using phase-contrast MRI. The aqueduct length and radius were measured using 3D T1-weighted anatomical images. ResultsPeak pressure amplitudes and the pressure load (integrated pressure exerted over a cardiac cycle) were similar between the groups, but the non-dimensionalized pressure load (adjusted for anatomical factors) was significantly lower in the iNPH group (p<0.001, Welch's t-test). The phase lag between the pressure and the flow rate, arising due to viscous drag, was significantly higher in the iNPH group (p<0.001). ConclusionThe increased phase lag is a promising new biomarker for quantifying CSF dynamics dysfunction in iNPH. Statement of SignificanceThe exact mechanism causing the disruption of CSF circulation in idiopathic normal pressure hydrocephalus (iNPH) remains unclear. Elucidating the pathophysiology of iNPH is crucial, as it is a treatable cause of dementia. In this study, we provided an analytical and a computational method to calculate the pulsatile transmantle pressure and the phase lag between the pressure and the volumetric CSF flow rate across the cerebral aqueduct. The phase lag was significantly higher in iNPH patients than in controls and may serve as a novel biomarker of CSF dynamics disruption in iNPH.

Research progress on the role of mitochondrial dynamics disorder in sepsis-associated acute kidney injury

Sepsis is a life-threatening organ dysfunction caused by the host's uncontrolled response to infection, and is one of the main causes of death in critically ill patients. Sepsis-associated acute kidney injury (SA-AKI) is associated with the poor prognosis of sepsis patients, and its pathogenesis is complex and still unclear to this day. Mitochondrial dynamics is crucial for maintaining the normal morphology, quantity, number and function of mitochondria, which is a new research hotspot in recent years. Mitochondrial dynamics disorder is involved in the occurrence and development of SA-AKI by regulating renal tubular dysfunction, which is expected to become new therapeutic targets. Deeply exploring the role of mitochondrial dynamic disorders in the pathogenesis of SA-AKI will help to find more effective treatment methods, thereby improving the success rate of rescue in SA-AKI patients.

SENP1 prevents high fat diet-induced non-alcoholic fatty liver diseases by regulating mitochondrial dynamics

Mitochondrial dynamics plays a crucial role in the occurrence and development of non-alcoholic fatty liver diseases (NAFLD). SENP1, a SUMO-specific protease, catalyzes protein de-SUMOylation and involves in various physiological and pathological processes. However, the exact role of SENP1 in NAFLD remains unclear. Therefore, we investigated the regulatory role of SENP1 in mitochondrial dynamics during the progression of NAFLD. In the study, the NAFLD in vivo model induced by high fat diet (HFD) and in vitro model induced by free fatty acids (FFA) were established to investigate the role and underlying mechanism of SENP1 through detecting mitochondrial morphology and dynamics. Our results showed that the down-regulation of SENP1 expression and the mitochondrial dynamics dysregulation occurred in the NAFLD, evidenced as mitochondrial fragmentation, up-regulation of p-Drp1 ser616 and down-regulation of MFN2, OPA1. However, over-expression of SENP1 significantly alleviated the NAFLD, rectified the mitochondrial dynamics disorder, reduced Cyt-c release and ROS levels induced by FFA or HFD; moreover, the over-expression of SENP1 also reduced the SUMOylation levels of Drp1 and prevented the Drp1 translocation to mitochondria. Our findings suggest that the possible mechanisms of SENP1 were through rectifying the mitochondrial dynamics disorder, reducing Cyt-c release and ROS-mediated oxidative stress. The findings would provide a novel target for the prevention and treatment of NALFD.

Site Disorder Drives Cyanide Dynamics and Fast Ion Transport in Li6PS5CN.

Halide argyrodite solid-state electrolytes of the general formula Li6PS5 X exhibit complex static and dynamic disorder that plays a crucial role in ion transport processes. Here, we unravel the rich interplay between site disorder and dynamics in the plastic crystal argyrodite Li6PS5CN and the impact on ion diffusion processes through a suite of experimental and computational methodologies, including temperature-dependent synchrotron powder X-ray diffraction, AC electrochemical impedance spectroscopy, 7Li solid-state NMR, and machine learning-assisted molecular dynamics simulations. Sulfide and (pseudo)halide site disorder between the two anion sublattices unilaterally improves long-range lithium diffusion irrespective of the (pseudo)halide identity, which demonstrates the importance of site disorder in dictating bulk ionic conductivity in the argyrodite family. Furthermore, we find that anion site disorder modulates the presence and time scales of cyanide rotational dynamics. Ordered configurations of anions enable fast, quasi-free rotations of cyanides that occur on time scales of 1011 Hz at T = 300 K. In contrast, we find that cyanide dynamics are slow or frozen in Li6PS5CN when site disorder between the cyanide and sulfide sublattices is present at T = 300 K. We rationalize the observed differences in cyanide dynamics in the context of elastic dipole interactions between neighboring cyanide anions and local strain induced by the configurations of site disorder that may impact the energetic landscape for cyanide rotational dynamics. Through this study, we find that anion disorder plays a decisive role in dictating the extent and time scales of both lithium ion and cyanide dynamics in Li6PS5CN.

Impact of static disorder and dynamic disorder on the thermal conductivity of sodium superoxide (NaO2)

Impact of static disorder and dynamic disorder on the thermal conductivity of sodium superoxide (NaO2)

Extreme high-temperature effects on optical response of CsPbBr3 perovskite

The temperature sensitivity of CsPbBr3 perovskite impacts the performance of related devices, with their optoelectronic behavior characterized by the dielectric function (ε = ε1+iε2). Yet, research on optical properties (ε) beyond 200 °C remains limited, hindering the evaluation of their high-temperature stability. This study first grew a high-quality CsPbBr3 single crystal, then examined its dielectric function from −55 to 550 °C using spectroscopic ellipsometry, and explored the optical response of all-dielectric CsPbBr3-based metasurfaces under varying temperatures. High temperature induces dynamic disorder in CsPbBr3, and thermal decomposition initiates above 300 °C, leading to a substantial change of dielectric function. CsPbBr3-based metasurfaces exhibit near-perfect light absorption (average 0.987) with only a meta-atomic height equivalent to one-seventh of the wavelength. They also demonstrate enhanced absorption at longer wavelengths, attributed to high-temperature-enhanced magnetic resonance. This work aims to improve the high-temperature performance of CsPbBr3 perovskites and expand their applications in energy and ultrafast optics.

Nonuniversal critical dynamics on planar random lattices with heterogeneous degree distributions

The weighted planar stochastic (WPS) lattice introduces a topological disorder that emerges from a multifractal structure. Its dual network has a power-law degree distribution and is embedded in a two-dimensional space, forming a planar network. We modify the original recipe to construct WPS networks with degree distributions interpolating smoothly between the original power-law tail, P(q)∼q−α with exponent α≈5.6, and a square lattice. We analyze the role of the disorder in the modified WPS model, considering the critical behavior of the contact process (CP). We report a critical scaling depending on the network degree distribution. The scaling exponents differ from the standard mean-field behavior reported for CP on infinite-dimensional (random) graphs with power-law degree distribution. Furthermore, the disorder present in the WPS lattice model is in agreement with the Luck-Harris criterion for the relevance of disorder in critical dynamics. However, despite the same wandering exponent ω=1/2, the disorder effects observed for the WPS lattice are weaker than those found for uncorrelated disorder.

Exploring the Relationship Between Voice Disorders in Indian Classical Music and the Guru-Shishya Parampara Through an Understanding of the Autonomic Nervous System

ABSTRACT The Guru-Shishya Parampara (GSP), translated as the teacher-student tradition, is a lineage-based oral tradition in Indian Classical Music (ICM). This study explores the relationship between GSP’s traditional obedience-authority dynamic and prevalent voice disorders experienced by ICM practitioners. Combining Constructivist Grounded Theory document analysis and a narrative literature review, the research investigates how disciplinarian tendencies and power differentials in authoritarian implementations of the GSP may contribute to or reinforce voice disorders resulting from psychological strain. Adopting the Indigenous Research Paradigm, the study prioritizes insights from ICM practitioners’ lived experiences within the cultural context of ICM within the analysis. A narrative review of existing literature on the links between autonomic nervous system responses associated with psychological stressors and voice disorders is discussed to further understand the impact of authoritarian GSPs on singers’ voices. Literature on compassion is additionally explored to discuss potential solutions to address the identified issues. Through this approach, the study offers insights into the complex interactions between power dynamics, psychological strain, and voice disorders within obedience-expectant GSPs, aiming to contribute to the development of effective interventions, highlighting that which already exists within ICM culture, to promote vocal health and overall well-being in this ancient and culturally significant tradition.

(Invited) Order, Disorder, and Energy Loss in Organic Photovoltaics

We will discuss our recent work to better understand the role of charge transfer (CT) states in organic solar cell function. For one, we have been exploring organic semiconductor-based thin films that feature crystalline grains of up to 1 mm in extent, termed microcrystalline films. We have found that CT states incorporating these long-range-ordered films can be highly delocalized, contributing to noticeably lower energy losses. In another system, we are studying donor-acceptor pairs that feature very high optical gaps (>3 eV) but relatively small frontier orbital energy offset (<1 eV). Such interfaces present multiple CT states that reveal new insight about photocurrent generation and nonradiative recombination at donor-acceptor interfaces. Finally, we have developed a framework to discriminate between dynamic and static disorder contributions. Both are shown to contribute, and the relative contribution depends on materials choice and temperature.

Contrasting Ultra-Low Frequency Raman and Infrared Modes in Emerging Metal Halides for Photovoltaics.

Lattice dynamics are critical to photovoltaic material performance, governing dynamic disorder, hot-carrier cooling, charge-carrier recombination, and transport. Soft metal-halide perovskites exhibit particularly intriguing dynamics, with Raman spectra exhibiting an unusually broad low-frequency response whose origin is still much debated. Here, we utilize ultra-low frequency Raman and infrared terahertz time-domain spectroscopies to provide a systematic examination of the vibrational response for a wide range of metal-halide semiconductors: FAPbI3, MAPbI x Br3-x , CsPbBr3, PbI2, Cs2AgBiBr6, Cu2AgBiI6, and AgI. We rule out extrinsic defects, octahedral tilting, cation lone pairs, and "liquid-like" Boson peaks as causes of the debated central Raman peak. Instead, we propose that the central Raman response results from an interplay of the significant broadening of Raman-active, low-energy phonon modes that are strongly amplified by a population component from Bose-Einstein statistics toward low frequency. These findings elucidate the complexities of light interactions with low-energy lattice vibrations in soft metal-halide semiconductors emerging for photovoltaic applications.