Dynamic Disorder Research Articles

Efficient Suppression of Dynamic Disorder in Organic Semiconductors via Electron-Donating and -Withdrawing Substituents

Efficient Suppression of Dynamic Disorder in Organic Semiconductors via Electron-Donating and -Withdrawing Substituents

Correlated anharmonicity and dynamic disorder control carrier transport in halide perovskites

Correlated anharmonicity and dynamic disorder control carrier transport in halide perovskites

Dynamic disorder for green refrigeration

Dynamic disorder for green refrigeration

Icariside II mitigates myocardial infarction by balancing mitochondrial dynamics and reducing oxidative stress through the activation of Nrf2/SIRT3 signaling pathway

Nuclear factor erythroid 2-related factor 2 (Nrf2)/silent mating type information regulation 2 homolog 3 (SIRT3) signaling pathway plays a pivotal role in regulating mitochondrial dynamics and oxidative stress, which are considered to be the principal pathogenesis of myocardial infarction (MI). Our previous study proved that pretreatment with icariside II (ICS II), a major active ingredient of Herbal Epimedii, exerts cardioprotective effect on MI, however, whether post-treatment with ICS II can alleviate MI and its underlying mechanism are still uncertain. Therefore, the present study was designed to investigate the therapeutic effect and the possible mechanism of ICS II on MI both in vivo and in vitro. The results revealed that post-treatment with ICS II markedly ameliorated myocardial injury in MI-induced mice and mitigated oxygen and glucose deprivation (OGD)-elicited cardiomyocyte injury. Further researches showed that ICS II promoted mitochondrial fusion, and suppressed mitochondrial fission and oxidative stress, which were achieved by facilitating the nuclear translocation of Nrf2 and activation of SIRT3. In summary, our findings indicate that ICS II mitigates MI-induced mitochondrial dynamics disorder and oxidative stress via activating the Nrf2/SIRT3 signaling pathway.

Targeting mitochondrial dynamics proteins for the treatment of doxorubicin-induced cardiotoxicity.

Doxorubicin (DOX) is an extensively used chemotherapeutic agent that can cause severe and frequent cardiotoxicity, which limits its clinical application. Although there have been extensive researches on the cardiotoxicity caused by DOX, there is still a lack of effective treatment. It is necessary to understand the molecular mechanism of DOX-induced cardiotoxicity and search for new therapeutic targets which do not sacrifice their anticancer effects. Mitochondria are considered to be the main target of cardiotoxicity caused by DOX. The imbalance of mitochondrial dynamics characterized by increased mitochondrial fission and inhibited mitochondrial fusion is often reported in DOX-induced cardiotoxicity, which can result in excessive ROS production, energy metabolism disorders, cell apoptosis, and various other problems. Also, mitochondrial dynamics disorder is related to tumorigenesis. Surprisingly, recent studies show that targeting mitochondrial dynamics proteins such as DRP1 and MFN2 can not only defend against DOX-induced cardiotoxicity but also enhance or not impair the anticancer effect. Herein, we summarize mitochondrial dynamics disorder in DOX-induced cardiac injury. Furthermore, we provide an overview of current pharmacological and non-pharmacological interventions targeting proteins involved in mitochondrial dynamics to alleviate cardiac damage caused by DOX.

Location of Brønsted sites in deuterated L-zeolite: A combined neutron powder diffraction and computer modeling study

In this work both concentration and location of Brønsted acid sites (BASs) in a deuterated L-zeolite were determined by combining neutron powder diffraction with ab-initio molecular dynamics modelling. From the structure refinement of the acidic L zeolite, two Brønsted acid sites were identified. The first one, D1, is on the framework oxygen O5 pointing toward the center of the 8-membered ring channel; the second one, D2, located in proximity of the framework oxygen O1 pointing toward the 12-membered ring channel running parallel to the c-axis. On the whole, ∼7.7 acid sites were located in the unit-cell, corresponding to 58% and 14% for D1 and D2, respectively. The average structure of the simulated D-LTL was in good agreement with the experimental structure. The modelling revealed that the D2 BAS shows a large degree of mobility, consistent with the high thermal factor associated with that atomic position. The D1 BAS showed a behaviour consistent with static disorder, while the D2 BAS was characterized by a significant degree of dynamical disorder. In addition to these findings, the study also revealed that the O1 BAS had a higher Brønsted base character compared to the average basicity of the framework oxygens of the 12-membered ring channels.

Machine-learned dynamic disorder of electron transfer coupling.

Electron transfer (ET) is a fundamental process in chemistry and biochemistry, and electronic coupling is an important determinant of the rate of ET. However, the electronic coupling is sensitive to many nuclear degrees of freedom, particularly those involved in intermolecular movements, making its characterization challenging. As a result, dynamic disorder in electron transfer coupling has rarely been investigated, hindering our understanding of charge transport dynamics in complex chemical and biological systems. In this work, we employed molecular dynamic simulations and machine-learning models to study dynamic disorder in the coupling of hole transfer between neighboring ethylene and naphthalene dimer. Our results reveal that low-frequency modes dominate these dynamics, resulting primarily from intermolecular movements such as rotation and translation. Interestingly, we observed an increasing contribution of translational motion as temperature increased. Moreover, we found that coupling is sub-Ohmic in its spectral density character, with cut-off frequencies in the range of 102 cm-1. Machine-learning models allow direct study of dynamics of electronic coupling in charge transport with sufficient ensemble trajectories, providing further new insights into charge transporting dynamics.

Unraveling segregation behavior of inactive secondary phase driven by ion-competition reaction for perovskite-2D PbI2 heterojunction solar cells

The undesired segregation of inactive secondary phase that randomly distributed across the perovskite film is detrimental to charge-carrier transport dynamics and light stability. However, in-depth studies for understanding the underlying chemical reaction mechanism and the relationship between phase structural configuration and physical properties are still lacking. Herein, the segregation behavior of the inactive secondary phase and the underlying microcosmic mechanism regarding ionic chemical replacement reaction and lattice reconfiguration process are systematically elaborated. A high-quality perovskite-PbI2 heterojunction film is constructed via converting the three-dimensional PbI2 photoactive phase into a two-dimensional inactive phase, alleviating the energetic disorder of carrier dynamics and photochemical dissociation. The resultant perovskite solar cells achieve an efficiency of 24.23% with excellent light-resistance. The dissociation energetics of phase dimensional structure is theoretically analyzed. This work provides new insights into crystal structure design for constructing high-quality perovskite heterojunction devices.

Atomic dynamics in fluids: Normal mode analysis revisited.

Developing microscopic understanding of the thermal properties of liquids is challenging due to their strong dynamic disorder, which prevents characterization of the atomic degrees of freedom. There have been significant research interests in the past few decades to extend the normal mode analysis for solids to instantaneous structures of liquids. However, the nature of normal modes that arise from these unstable structures is still elusive. In this paper, we explore the instantaneous eigenmodes of dynamical matrices of various Lennard-Jones argon liquid and gas systems at high temperatures and show that the normal modes can be interpreted as an interpolation of T→∞ (gas) and T=0 (solid) mode descriptions. We find that normal modes become increasingly collisional and translational, recovering atomistic gaslike behavior rather than vibrational with increase in temperature, suggesting that normal modes in liquids may be described by both solidlike and gaslike modes.

Ultrafast imaging of polariton propagation and interactions

Semiconductor excitations can hybridize with cavity photons to form exciton-polaritons (EPs) with remarkable properties, including light-like energy flow combined with matter-like interactions. To fully harness these properties, EPs must retain ballistic, coherent transport despite matter-mediated interactions with lattice phonons. Here we develop a nonlinear momentum-resolved optical approach that directly images EPs in real space on femtosecond scales in a range of polaritonic architectures. We focus our analysis on EP propagation in layered halide perovskite microcavities. We reveal that EP–phonon interactions lead to a large renormalization of EP velocities at high excitonic fractions at room temperature. Despite these strong EP–phonon interactions, ballistic transport is maintained for up to half-exciton EPs, in agreement with quantum simulations of dynamic disorder shielding through light-matter hybridization. Above 50% excitonic character, rapid decoherence leads to diffusive transport. Our work provides a general framework to precisely balance EP coherence, velocity, and nonlinear interactions.

Dynamic Effects on Hole Transport in Amorphous Organic Semiconductors: a Combined QM/MM and kMC Study.

Small-molecule-based amorphous organic semiconductors (OSCs) are essential components of organic photovoltaics and organic light-emitting diodes. The charge carrier mobility of these materials is an integral and limiting factor in regard to their performance. Integrated computational models for the hole mobility, taking into account structural disorder in systems of several thousand molecules, have been the object of research in the past. Due to static and dynamic contributions to the total structural disorder, efficient strategies to sample the charge transfer parameters become necessary. In this paper, we investigate the impact of structural disorder in amorphous OSCs on the transfer parameters and charge mobilities in different materials. We present a sampling strategy for incorporating static and dynamic structural disorder which are based on QM/MM methods using semiempirical Hamiltonians and extensive MD sampling. We show how the disorder affects the distributions of HOMO energies and intermolecular couplings and validate the results using kinetic Monte Carlo simulations of the mobility. We find that dynamic disorder causes an order of magnitude difference in the calculated mobility between morphologies of the same material. Our method allows the sampling of disorder in HOMO energies and couplings, and the statistical analysis enables us to characterize the relevant time scales on which charge transfer occurs in these complex materials. The findings presented here shed light on the interplay of the fluctuating amorphous matrix with charge carrier transport and aid in the development of a better understanding of these complex processes.

The Combination of Tera Gymnastics and Square Stepping Exercises on the Dynamic Balance of the Elderly

With increasing age, there is a decrease in the functions of the degenerative body, including a decrease in the functions of the musculoskeletal, neuromuscular, and cardiovascular areas, as well as a reduced ability to perform daily activities. One of the declines in musculoskeletal function is a decrease in muscle function which causes muscle fibers to shrink, causing a decrease in strength, muscle mass, and bone mass. This causes dynamic balance disorders in the elderly. To improve and maintain dynamic balance, a combination of tera and Square Stepping exercises is recommended for the elderly. This study aimed to determine whether there is an effect of the combination of tera and Square Stepping exercises on the level of the dynamic balance of the elderly in the elderly community at the Sasana Malang. This study followed a pre-experimental, namely One Group Pre-Test and Post-Test, design. 35 elderly people in the elderly community at Sasana Malang for 4 weeks were studied in this research. Timed Up and Go Test instruments were used. The results discovered that the Shapiro Wilk Test data was normal, Pre-Test was 14.2317 and Post-Test was 11.9480. Paired Sample T Test significance was 0.000, H0 is rejected and H1 is accepted. A combination of tera and Square Stepping exercises for 4 weeks increases the dynamic balance of the elderly in the elderly community at the Sasana Malang.
 Keywords: Tera, Square Stepping Exercise, dynamic balance

DRP1 knockdown and atorvastatin alleviate ox-LDL-induced vascular endothelial cells injury: DRP1 is a potential target for preventing atherosclerosis

Vascular endothelial cells (VECs) injury is the first step in the pathogenesis of atherosclerosis (AS). Mitochondrial dysfunction plays a significant role in VECs injury, but the underlying mechanisms are still unclear. Here, the human umbilical vein endothelial cells were exposed to 100 μg/mL oxidized low-density lipoprotein for 24 h to establish AS model in vitro. We reported that mitochondrial dynamics disorder is a prominent feature of VECs in AS models and associated with mitochondrial dysfunction. Moreover, the knockdown of dynamin-related protein 1 (DRP1) in AS model significantly alleviated the mitochondrial dynamics disorder and VECs injury. On the contrary, DRP1 overexpression significantly aggravated this injury. Interestingly, atorvastatin (ATV), a classical anti-atherosclerotic drug, prominently inhibited the expression of DRP1 in AS models and similarly alleviated the mitochondrial dynamics disorder and VECs injury in vitro and in vivo. At the same time, we found that ATV alleviated VECs damage but did not significantly reduce lipid concentration in vivo. Our findings provide a potential therapeutic target of AS and a new mechanism of the anti-atherosclerotic effect of ATV.

The Chinese herbal medicine Fufang Zhenzhu Tiaozhi ameliorates diabetic cardiomyopathy by regulating cardiac abnormal lipid metabolism and mitochondrial dynamics in diabetic mice

Diabetic cardiomyopathy (DCM) is an important complication leading to the death of patients with diabetes, but there is no effective strategy for clinical treatments. Fufang Zhenzhu Tiaozhi (FTZ) is a patent medicine that is a traditional Chinese medicine compound preparation with comprehensive effects for the prevention and treatment of glycolipid metabolic diseases under the guidance of “modulating liver, starting pivot and cleaning turbidity”. FTZ was proposed by Professor Guo Jiao and is used for the clinical treatment of hyperlipidemia. This study was designed to explore the regulatory mechanisms of FTZ on heart lipid metabolism dysfunction and mitochondrial dynamics disorder in mice with DCM, and it provides a theoretical basis for the myocardial protective effect of FTZ in diabetes. In this study, we demonstrated that FTZ protected heart function in DCM mice and downregulated the overexpression of free fatty acids (FFAs) uptake-related proteins cluster of differentiation 36 (CD36), fatty acid binding protein 3 (FABP3) and carnitine palmitoyl transferase 1 (CPT1). Moreover, FTZ treatment showed a regulatory effect on mitochondrial dynamics by inhibiting mitochondrial fission and promoting mitochondrial fusion. We also identified in vitro that FTZ could restore lipid metabolism-related proteins, mitochondrial dynamics-related proteins and mitochondrial energy metabolism in PA-treated cardiomyocytes. Our study indicated that FTZ improves the cardiac function of diabetic mice by attenuating the increase in fasting blood glucose levels, inhibiting the decrease in body weight, alleviating disordered lipid metabolism, and restoring mitochondrial dynamics and myocardial apoptosis in diabetic mouse hearts.

Using pressure to unravel the structure–dynamic-disorder relationship in metal halide perovskites

The exceptional optoelectronic properties of metal halide perovskites (MHPs) are presumed to arise, at least in part, from the peculiar interplay between the inorganic metal-halide sublattice and the atomic or molecular cations enclosed in the cage voids. The latter can exhibit a roto-translative dynamics, which is shown here to be at the origin of the structural behavior of MHPs as a function of temperature, pressure and composition. The application of high hydrostatic pressure allows for unraveling the nature of the interaction between both sublattices, characterized by the simultaneous action of hydrogen bonding and steric hindrance. In particular, we find that under the conditions of unleashed cation dynamics, the key factor that determines the structural stability of MHPs is the repulsive steric interaction rather than hydrogen bonding. Taking as example the results from pressure and temperature-dependent photoluminescence and Raman experiments on MAPbBr_3 but also considering the pertinent MHP literature, we provide a general picture about the relationship between the crystal structure and the presence or absence of cationic dynamic disorder. The reason for the structural sequences observed in MHPs with increasing temperature, pressure, A-site cation size or decreasing halide ionic radius is found principally in the strengthening of the dynamic steric interaction with the increase of the dynamic disorder. In this way, we have deepened our fundamental understanding of MHPs; knowledge that could be coined to improve performance in future optoelectronic devices based on this promising class of semiconductors.

Jahn-Teller Switching of a Redox-Active Nickel(III) Center in a Homoleptic Thiolato Metalloligand Environment.

Treatment of nickel(II) nitrate with the iridium(III) metalloligand fac-[Ir(apt)3] (apt = 3-aminopropanethiolate) gave the trinuclear complex [Ni{Ir(apt)3}2](NO3)3 ([1Ir](NO3)3), in which the nickel center has a formal oxidation state of +III. Chemical or electrochemical oxidation and reduction of [1Ir](NO3)3 generated the corresponding trinuclear complexes [Ni{Ir(apt)3}2](NO3)4 ([1Ir](NO3)4) and [Ni{Ir(apt)3}2](NO3)2 ([1Ir](NO3)2) with one-electron oxidated and reduced states, respectively. Single-crystal X-ray crystallography revealed that the nickel center in [1Ir](NO3)3 is situated in a highly distorted octahedron due to Jahn-Teller effect, while the nickel center in each of [1Ir](NO3)4 and [1Ir](NO3)2 adopts a normal octahedral geometry. Crystals of [1Ir](NO3)3·2H2O are dehydrated on heating while retaining their single-crystallinity. The dehydration induces temperature-dependent dynamic disorder of the Jahn-Teller distortion at the nickel(III) center, which is largely quenched upon rehydration of the crystal.

Effects of the intrinsic energy on kinetics of bio-molecules in multidimensional landscape model

The intrinsic energy G, which is crucial for distinguishing the chemical activity of bio-molecules, plays a significant role. Various factors affecting intrinsic energy differ from simple correlations observed in the inorganic field or small organic molecular systems. To gain deeper insights into the dynamic properties within a multidimensional landscape, typical components associated with intrinsic energy, such as the pulling force F, activity distance ΔQ‡, and configurational symmetry, have been investigated. The pulling force primarily affects the x coordination and provides a quantitative measure of dynamic properties. On the other hand, estimating the influence of ΔQ‡ and configurational symmetry on intrinsic energy is complex due to their connection with configuration fluctuation properties. In this study, a statistical method was employed to investigate the fluctuation. By comparing the mean waiting time ⟨t⟩, significant differences between normal kinetics and dynamic disorder were revealed. Our findings offer a novel perspective for examining the role of intrinsic energy or potential energy in bio-molecules.

Interplay of Static and Dynamic Disorder in the Mixed-Metal Chalcohalide Sn2SbS2I3.

Chalcohalide mixed-anion crystals have seen a rise in interest as "perovskite-inspired materials" with the goal of combining the ambient stability of metal chalcogenides with the exceptional optoelectronic performance of metal halides. Sn2SbS2I3 is a promising candidate, having achieved a photovoltaic power conversion efficiency above 4%. However, there is uncertainty over the crystal structure and physical properties of this crystal family. Using a first-principles cluster expansion approach, we predict a disordered room-temperature structure, comprising both static and dynamic cation disorder on different crystallographic sites. These predictions are confirmed using single-crystal X-ray diffraction. Disorder leads to a lowering of the bandgap from 1.8 eV at low temperature to 1.5 eV at the experimental annealing temperature of 573 K. Cation disorder tailoring the bandgap allows for targeted application or for the use in a graded solar cell, which when combined with material properties associated with defect and disorder tolerance, encourages further investigation into the group IV/V chalcohalide family for optoelectronic applications.

Nonlinear terahertz control of the lead halide perovskite lattice.

Lead halide perovskites (LHPs) have emerged as an excellent class of semiconductors for next-generation solar cells and optoelectronic devices. Tailoring physical properties by fine-tuning the lattice structures has been explored in these materials by chemical composition or morphology. Nevertheless, its dynamic counterpart, phonon-driven ultrafast material control, as contemporarily harnessed for oxide perovskites, has not yet been established. Here, we use intense THz electric fields to obtain direct lattice control via nonlinear excitation of coherent octahedral twist modes in hybrid CH3NH3PbBr3 and all-inorganic CsPbBr3 perovskites. These Raman-active phonons at 0.9 to 1.3 THz are found to govern the ultrafast THz-induced Kerr effect in the low-temperature orthorhombic phase and thus dominate the phonon-modulated polarizability with potential implications for dynamic charge carrier screening beyond the Fröhlich polaron. Our work opens the door to selective control of LHP's vibrational degrees of freedom governing phase transitions and dynamic disorder.

Disulfide-Bond-Induced Structural Frustration and Dynamic Disorder in a Peroxiredoxin from MAS NMR.

Disulfide bond formation is fundamentally important for protein structure and constitutes a key mechanism by which cells regulate the intracellular oxidation state. Peroxiredoxins (PRDXs) eliminate reactive oxygen species such as hydrogen peroxide through a catalytic cycle of Cys oxidation and reduction. Additionally, upon Cys oxidation PRDXs undergo extensive conformational rearrangements that may underlie their presently structurally poorly defined functions as molecular chaperones. Rearrangements include high molecular-weight oligomerization, the dynamics of which are, however, poorly understood, as is the impact of disulfide bond formation on these properties. Here we show that formation of disulfide bonds along the catalytic cycle induces extensive μs time scale dynamics, as monitored by magic-angle spinning NMR of the 216 kDa-large Tsa1 decameric assembly and solution-NMR of a designed dimeric mutant. We ascribe the conformational dynamics to structural frustration, resulting from conflicts between the disulfide-constrained reduction of mobility and the desire to fulfill other favorable contacts.