Dynamic Process Research Articles

The temporal dynamics of daily stress, affect, and several affect regulation processes, in patients with chronic mood and anxiety disorders before and after a mindful yoga intervention

Background and ObjectivesPatients with chronic mood and anxiety disorders experience many life stressors and are more reactive to these stressors. Although mindful yoga might reduce stress reactivity, little is known about the affect regulation mechanisms involved, such as repetitive negative thinking, fear of emotion, acting with awareness and body awareness. Design and MethodsUsing experience sampling methodology, 12 patients with chronic mood and anxiety disorders completed five daily assessments for 15 days before and after a 9-week mindful yoga intervention. Interrupted time-series analyses were used to assess mean-level change from pre-to-post intervention and vector autoregressive models to assess change in the temporal associations. ResultsMost individuals experienced positive changes in affect and the proposed affect regulation processes. Fear of emotion showed changes from pre-to-post intervention for most individuals (67%), followed by acting with awareness (58%), body awareness (58%) and repetitive negative thinking (50%). In the dynamic relationships between stressors, the four affect regulation processes and affect, there were individual differences in which pathways changed and how they changed. ConclusionsAfter a mindful yoga intervention, affect and several affect regulation processes improve in most individuals. Achieving this in the context of daily life stress, seems to be more complicated. Trial registrationISRCTN register (study ID ISRCTN13612864).

Stem Cell-Derived Nanovesicles Embedded in Dual-Layered Hydrogel for Programmed ROS Regulation and Comprehensive Tissue Regeneration in Burn Wound Healing.

Burn wounds often bring high risks of delayed healing process and even death. Reactive oxygen species (ROS) play a crucial role in burn wound repair. However, the dynamic process in wound healing requires both the generation of ROS to inhibit bacteria and the subsequent reduction of ROS levels to initiate and promote tissue regeneration, which calls for a more intelligent ROS regulation dressing system. Hence, a dual-layered hydrogel (Dual-Gel) tailored to the process of burn wound repair is designed: the inner layer hydrogel (Gel 2) first responds to bacterial hyaluronidase (Hyal) to deliver aggregation-induced emission photosensitizer functionalized adipose-derived stem cell nanovesicles, which generate ROS upon light irradiation to eliminate bacteria; then the outer layer hydrogel (Gel 1) continuously starts a long-lasting consumption of excess ROS at the wound site to accelerate tissue regeneration. Simultaneously, the stem cell nanovesicles trapped in the burns wound also provide nutrients and mobilize neighboring tissues to thoroughly assist in inflammation regulation, cell proliferation, migration, and angiogenesis. In summary, this study develops an intelligent treatment approach on burn wounds by programmatically regulating ROS and facilitating comprehensive wound tissue repair.

A Comparison of the Impacts of Two Consecutive Double-Peaked La Niña Events on Antarctic Sea Ice in Austral Spring

Abstract Among nine La Niña events since 1980, there are seven double-peaked La Niña events that typically persist for 2 years and peak twice in the two consecutive boreal winters. In the study, the individual impacts of the first and second peak episodes of such La Niña on the Antarctic sea ice in austral spring (September–November) were compared. The results suggest a difference. The first episode induces a tripolar distribution of sea ice concentration (SIC) with a negative anomaly in the Bellingshausen Sea sandwiched with positive anomalies in the Ross Sea and the northeastern Weddell Sea. The second causes an SIC reduction in most parts of the Southern Ocean except for the eastern Ross–western Amundsen Seas where an increase is observed. Mechanistically, the first episode forces one single Rossby wave train to propagate southeastward, causing a strong cyclone anomaly over the eastern Ross–Amundsen–Bellingshausen Seas along with a weak anticyclone over the Weddell Sea. In comparison, the second La Niña excites two branches of Rossby wave trains emanating from the southeastern tropical Indian Ocean and the central equatorial Pacific, respectively, which induce three anomalous anticyclones and two anomalous cyclones over the Southern Ocean. These different atmospheric circulation anomalies shape their different sea ice distributions between the two La Niña episodes through both dynamic and thermodynamic processes. The modeling results from CAM5 verify these differences. Significance Statement Under global warming, the double-peaked La Niña occurs more frequently. The first and second La Niña episodes in such double-peaked La Niña are distinct from each other not only in their onset and developing mechanisms but also in their climate impacts. Based on observational analyses and model experiments, the study investigated the distinctive impacts of the first and second episodes on the austral spring Antarctic sea ice. The results reveal that the first episode excites one single southeastward-propagated Rossby wave train, while the second episode forces two branches of Rossby wave trains. These different atmospheric responses in the Southern Hemisphere shape the distinct sea ice distributions both dynamically and thermodynamically. The study also indicates the diversity of tropical–Antarctic teleconnections.

A mathematical framework for measuring and tuning tempo in developmental gene regulatory networks.

Embryo development is a dynamic process governed by the regulation of timing and sequences of gene expression, which control the proper growth of the organism. Although many genetic programmes coordinating these sequences are common across species, the timescales of gene expression can vary significantly among different organisms. Currently, substantial experimental efforts are focused on identifying molecular mechanisms that control these temporal aspects. In contrast, the capacity of established mathematical models to incorporate tempo control while maintaining the same dynamical landscape remains less understood. Here, we address this gap by developing a mathematical framework that links the functionality of developmental programmes to the corresponding gene expression orbits (or landscapes). This unlocks the ability to find tempo differences as perturbations in the dynamical system that preserve its orbits. We demonstrate that this framework allows for the prediction of molecular mechanisms governing tempo, through both numerical and analytical methods. Our exploration includes two case studies: a generic network featuring coupled production and degradation, with a particular application to neural progenitor differentiation; and the repressilator. In the latter, we illustrate how altering the dimerisation rates of transcription factors can decouple the tempo from the shape of the resulting orbits. We conclude by highlighting how the identification of orthogonal molecular mechanisms for tempo control can inform the design of circuits with specific orbits and tempos.

Identifying Reproducible Transcription Regulator Coexpression Patterns with Single Cell Transcriptomics.

The proliferation of single cell transcriptomics has potentiated our ability to unveil patterns that reflect dynamic cellular processes, rather than cell type compositional effects that emerge from bulk tissue samples. In this study, we leverage a broad collection of single cell RNA-seq data to identify the gene partners whose expression is most coordinated with each human and mouse transcription regulator (TR). We assembled 120 human and 103 mouse scRNA-seq datasets from the literature, constructing a single cell coexpression network for each. We aimed to understand the consistency of TR coexpression profiles across a broad sampling of biological contexts, rather than examine the preservation of context-specific networks. Our workflow therefore explicitly prioritizes the patterns that are most reproducible across cell types, helping to characterize each TR's coexpression patterns. Towards this goal, we quantify the similarity of TR coexpression profiles within and across species, characterizing the consistency of each TR's coexpression across datasets. We create single cell coexpression rankings for each TR, demonstrating that this aggregated information recovers literature curated targets on par with ChIP-seq data. We then combine the coexpression and ChIP-seq information to identify candidate regulatory interactions supported across methods and species. Finally, we highlight interactions for the important neural TR ASCL1 to demonstrate how our compiled information can be adopted for community use.

An experimental study on low-temperature plasma tissue ablation and its thermal effect

Low-temperature plasma ablation has been recently used for minimally invasive surgeries. However, more research is still needed on its generation process during tissue ablation and the underlying mechanism of tissue thermal damage. In this paper, high-speed camera footage, voltage–current signal collection, temperature analysis, and histological analysis were used to investigate the dynamic process of plasma tissue ablation and its thermal effect of dual-needle electrodes immersed in normal saline, which were driven by a high-frequency DC power supply with an output voltage ranging from 220 V to 320 V and a squire wave of 100 kHz. Microbubbles occurred around the ground electrode and merged to form a vapor layer that could completely cover the ground electrode. Plasma capable of ablating tissue would occur in the vapor layer between the ground electrode and tissue. The effect of electrical parameters on plasma generation and its thermal effect are analyzed by statistical results. The experimental results indicated that the voltage applied to the electrodes significantly influenced both the generation and stability of plasma, as well as the heat generation and tissue damage around the electrodes. Furthermore, under the same voltage, the existence of biological tissue promotes the formation of a vapor layer around the electrode, thereby facilitating the generation and stability of plasma. Notably, the temperature rise around the ground electrode is much higher than that around the powered electrode. These results have direct application to the design of plasma tissue ablation systems, which could achieve tissue ablation effects with minimal thermal damage.

Loss of YhcB results in overactive fatty acid biosynthesis.

Loss of the Escherichia coli inner membrane protein YhcB results in pleomorphic cell morphology and clear growth defects. Prior work suggested that YhcB was directly involved in cell division or peptidoglycan assembly. We found that loss of YhcB is detrimental in genetic backgrounds in which lipopolysaccharide (LPS) or glycerophospholipid (GPL) synthesis is altered. The growth defect of ΔyhcB could be rescued through inactivation of the Mla pathway, a system responsible for the retrograde transport of GPLs that are mislocalized to the outer leaflet of the outer membrane. Interestingly, this rescue was dependent upon the outer membrane phospholipase PldA that cleaves GPLs at the bacterial surface. Since the freed fatty acids resulting from PldA activity serve as a signal to the cell to increase LPS synthesis, this result suggested that outer membrane lipids are imbalanced in ΔyhcB. Mutations that arose in ΔyhcB populations during two independent suppressor screens were in genes encoding subunits of the acetyl coenzyme A carboxylase complex, which initiates fatty acid biosynthesis (FAB). These mutations fully restored cell morphology and reduced GPL levels, which were increased compared to wild-type bacteria. Growth of ΔyhcB with the FAB-targeting antibiotic cerulenin also increased cellular fitness. Furthermore, genetic manipulation of FAB and lipid biosynthesis showed that decreasing FAB rescued ΔyhcB filamentation, whereas increasing LPS alone could not. Altogether, these results suggest that YhcB may play a pivotal role in regulating FAB and, in turn, impact cell envelope assembly and cell division.IMPORTANCESynthesis of the Gram-negative cell envelope is a dynamic and complex process that entails careful coordination of many biosynthetic pathways. The inner and outer membranes are composed of molecules that are energy intensive to synthesize, and, accordingly, these synthetic pathways are under tight regulation. The robust nature of the Gram-negative outer membrane renders it naturally impermeable to many antibiotics and therefore a target of interest for antimicrobial design. Our data indicate that when the inner membrane protein YhcB is absent in Escherichia coli, the pathway for generating fatty acid substrates needed for all membrane lipid synthesis is dysregulated which leads to increased membrane material. These findings suggest a potentially novel regulatory mechanism for controlling the rate of fatty acid biosynthesis.

Dynamic Fear in Fear Appeals: Applying Fear Appeals to Environmental Communication in China

This study investigates the role of dynamic fear in the effectiveness of communicating health threats (i.e. fear appeals) of ground-level ozone among Chinese citizens. An online survey revealed that fear appeal messages effectively enhance the audience’s risk perceptions, efficacy beliefs, and acceptance of the message. Crucially, dynamic fear reduction process positively predicts engagement in protective behaviors (i.e. danger control process) and negatively predicts engagement in fear control processes, such as message denial. Presenting severity before susceptibility resulted in a more positive attitude toward the message recommendation. These findings highlight that communicating health-threats about climate pollution is effective in raising awareness and motivating protective behaviors. Furthermore, our study underscores the importance of dynamic fear, specifically fear reduction, in increasing fear appeals’ effectiveness in communicating climate issues from a health perspective.

Spatial structure could explain the maintenance of alternative reproductive tactics in tree cricket males.

Trait polymorphisms are widespread in nature, and explaining their stable co-existence is a central problem in ecology and evolution. Alternative reproductive tactics, in which individuals of one or more sex exhibit discrete, discontinuous traits in response to reproductive competition, represent a special case of trait polymorphism in which the traits are often complex, behavioural, and dynamic. Thus, studying how alternative reproductive tactics are maintained may provide general insights into how complex trait polymorphisms are maintained in populations. We construct a spatially explicit individual-based model inspired from extensively collected empirical data to address the mechanisms behind the co-existence of three behavioural alternative reproductive tactics in males of a tree cricket (Oecanthus henryi). Our results show that the co-existence of these tactics over ecological time scales is facilitated by the spatial structure of the landscape they inhabit, which serves to equalise the otherwise unequal mating benefits of the three tactics. We also show that this co-existence is unlikely if spatial aspects of the system are not considered. Our findings highlight the importance of spatial dynamics in understanding ecological and evolutionary processes and underscore the power of integrative approaches that combine models with empirical data.

Regulatory roles of N6-methyladenosine (m6A) methylation in RNA processing and non-communicable diseases.

Post-transcriptional RNA modification is an emerging epigenetic control mechanism in cells that is important in many different cellular and organismal processes. N6-methyladenosine (m6A) is one of the most prevalent, prolific, and ubiquitous internal transcriptional alterations in eukaryotic mRNAs, making it an important topic in the field of Epigenetics. m6A methylation acts as a dynamical regulatory process that regulates the activity of genes and participates in multiple physiological processes, by supporting multiple aspects of essential mRNA metabolic processes, including pre-mRNA splicing, nuclear export, translation, miRNA synthesis, and stability. Extensive research has linked aberrations in m6A modification and m6A-associated proteins to a wide range of human diseases. However, the impact of m6A on mRNA metabolism and its pathological connection between m6A and other non-communicable diseases, including cardiovascular disease, neurodegenerative disorders, liver diseases, and cancer remains in fragmentation. Here, we review the existing understanding of the overall role of mechanisms by which m6A exerts its activities and address new discoveries that highlight m6A's diverse involvement in gene expression regulation. We discuss m6A deposition on mRNA and its consequences on degradation, translation, and transcription, as well as m6A methylation of non-coding chromosomal-associated RNA species. This study could give new information about the molecular process, early detection, tailored treatment, and predictive evaluation of human non-communicable diseases like cancer. We also explore more about new data that suggests targeting m6A regulators in diseases may have therapeutic advantages.

Stochastic representation and conditioning of process-based geological model by deep generative and recognition networks

Accurate and realistic geological modelling is the core of oil and gas development and production. In recent years, process-based methods are developed to produce highly realistic geological models by simulating the physical processes that reproduce the sedimentary events and develop the geometry. However, the complex dynamic processes are extremely expensive to simulate, making process-based models difficult to be conditioned to field data. In this work, we propose a comprehensive generative adversarial network framework as a machine-learning-assisted approach for mimicking the outputs of process-based geological models with fast generation. The main objective of our work is to obtain a continuous parametrization of the highly realistic process-based geological models which enables us to calibrate the models and condition the models to data. Numerical results are presented to illustrate the capability of our proposed methodology.

Molecular docking and molecular dynamics simulation of wheat gluten-derived antioxidant peptides acting through the Keap1-Nrf2 pathway.

In our previous study, we successfully identified five peptides from wheat gluten: Ala-Pro-Ser-Tyr (APSY), Leu-Tyr (LY), Pro-Tyr (PY), Arg-Gly-Gly-Tyr (RGGY) and Tyr-Gln (YQ). Molecular docking and molecular dynamics simulation methods were employed to investigate the interaction between these antioxidant peptides and the Kelch-like ECH-associated protein 1 (Keap1 protein), revealing the molecular mechanism of their non-competitive binding. In addition, the total antioxidant capacity of the five peptides was determined using the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) method. The affinities of APSY, LY, PY, RGGY and YQ were -8.9, -8.3, -8.5, -9.1 and - 7.9 kcal mol-1, respectively. The five peptides effectively bound to Keap1 protein through hydrogen, π-σ, π-alkyl and alkyl interactions. Significant roles were observed for the P1 pocket residue ARG-415 and the P3 pocket residue ALA-556 in the interactions of the Keap1-peptide complexes. Molecular dynamics simulations further elucidated the dynamic process of peptide binding to the Keap1 protein. All five peptides formed stable complexes with Keap1 protein, with van der Waals forces playing crucial roles in these complex systems, indicative of the peptides' strong binding ability to Keap1 protein. The van der Waals forces were -178.74, -123.11, -134.36, -132.59, and -121.44 kJ mol-1 for the Keap1-APSY, Keap1-LY, Keap1-PY, Keap1-RGGY and Keap1-YQ complexes, respectively. These peptides exhibited excellent antioxidant effects. Among them, the YQ peptide exhibited the highest total antioxidant capacity, with an activity value of 1.18 ± 0.06 mmol Trolox equivalent (TE) L-1 at a concentration of 0.10 mg mL-1. The RGGY, PY, LY and APSY peptides followed in descending order, with activity values of 0.91 ± 0.05, 0.72 ± 0.06, 0.62 ± 0.04 and 0.60 ± 0.05 mmol TE L-1, respectively. These results unveiled the molecular mechanism by which the five antioxidant peptides act on active pockets through the Keap1-Nrf2 signaling pathway, providing a theoretical basis for the development of antioxidants. © 2024 Society of Chemical Industry.

Development of Neighborhood Trajectories Employing Historic Redlining and the Area Deprivation Index.

The role of historic residential redlining on health inequities is intertwined with policy changes made before and after the 1930s that influence current neighborhood characteristics and shape ongoing structural racism in the United States (U.S.). We developed Neighborhood Trajectories which combine historic redlining data and the current neighborhood socioeconomic characteristics as a novel approach to studying structural racism. Home Owners' Loan Corporation (HOLC) neighborhoods for the entire U.S. were used to map the HOLC grades to the 2020 U.S. Census block group polygons based on the percentage of HOLC areas in each block group. Each block group was also assigned an Area Deprivation Index (ADI) from the Neighborhood Atlas®. To evaluate changes in neighborhoods from historic HOLC grades to present degree of deprivation, we aggregated block groups into "Neighborhood Trajectories" using historic HOLC grades and current ADI. The Neighborhood Trajectories are "Advantage Stable"; "Advantage Reduced"; "Disadvantage Reduced"; and "Disadvantage Stable." Neighborhood Trajectories were established for 13.3% (32,152) of the block groups in the U.S., encompassing 38,005,799 people. Overall, the Disadvantage-Reduced trajectory had the largest population (16,307,217 people). However, the largest percentage of non-Hispanic/Latino Black residents (34%) fell in the Advantage-Reduced trajectory, while the largest percentage of Non-Hispanic/Latino White residents (60%) fell in the Advantage-Stable trajectory. The development of the Neighborhood Trajectories affords a more nuanced mechanism to investigate dynamic processes from historic policy, socioeconomic development, and ongoing marginalization. This adaptable methodology may enable investigation of ongoing sociopolitical processes including gentrification of neighborhoods (Disadvantage-Reduced trajectory) and "White flight" (Advantage Reduced trajectory).

Transition experiences of patients with post stroke dysphagia and family caregivers: A longitudinal, qualitative study.

Stroke patients with dysphagia and family caregivers will experience multiple transitions during the whole process of the disease and various nursing needs will be generated. There is a lack of knowledge about their experiences at different transition stages. Thus, we aimed to explore the transition experiences of patients with post stroke dysphagia and family caregivers from admission to discharge home. A semi-structured interview based on Meleis's transition theory was used during hospitalization and telephone follow-up interviews were conducted in the first, third, and sixth month after the diagnosis of dysphagia. Interview transcripts were analyzed using the conventional content analysis method. A total of 17 participants enrolled in the first face-to-face interview, 16 participants took part in the first month's telephone follow-up interview, 14 participants in the third month, and 12 participants in the sixth month. The transition experiences of patients with post stroke dysphagia and family caregivers could be summarized into three themes: (1)transition from onset to admission; (2)transition from discharge to other rehabilitation institutions; and (3)transition from discharge to home. Each theme had identified interrelated subthemes. The experiences of patients with post stroke dysphagia and family caregivers during transition are a dynamic process with enormous challenges in each phase. Collaboration with health care professionals, follow-up support after discharge, and available community and social support should be integrated into transitional nursing to help patients facilitate their transition.

Association of parent-reported timing of first tooth emergence and ECC: a secondary analysis of a case-control study.

Tooth eruption is a dynamic process. Appearance of any part of the cusp through gingiva may be a clinical marker of eruption. Early childhood caries (ECC) is a public health problem globally. This study aimed to assess the relationship between parent-reported timing of first tooth emergence and ECC in toddlers. This study is a secondary data analysis of 627 toddlers involved in a case-control study on sleep-time feeding practises in children. The children were categorised into four groups based on the parent-reported timing of first primary tooth emergence (G1-when the first primary tooth emerged before 6months of age, G2-between 7 and 9months; G3-10 to 12months and G4-when the first primary tooth emerged after 12months of age). Univariate binary logistic regression analysis was performed to evaluate the association between timing of first tooth emergence and ECC. The mean age of the children was 24.4 ± 7.3months (cases, that is children with ECC-25.4 ± 6.9months, controls, that is children without ECC-23.6 ± 7.5months). Of 60 children, whose first tooth erupted before 6months of age, 35 (12%) were cases compared to 25(8%) controls. Amongst the cases, boys had more caries than girls (p < 0.05). Of the anterior teeth, 22% of the emerged teeth were decayed in the first group, followed by 19%, 16% and 10% in the second, third and fourth groups, respectively (p < 0.05). Analysis of the posterior teeth showed a lower percentage of decayed teeth with delayed emergence of the first primary tooth (p < 0.05). Children whose teeth emerged before 6months of age had an odds ratio of 3.5 (95% CI 1.49, 8.42) (p = 0.004). This study concluded that the early emergence of the first primary tooth, as reported by the parent, was associated with an increased risk of developing ECC.

Bioinspired Zwitterionic Nanowires with Simultaneous Biofouling Reduction and Release.

Marine biofouling is a complex and dynamic process that significantly increases the carbon emissions from the maritime industry by increasing drag losses. However, there are no existing non-toxic marine paints that can achieve both effective fouling reduction and efficient fouling release. Inspired by antifouling strategies in nature, herein, a superoleophobic zwitterionic nanowire coating with a nanostructured hydration layer is introduced, which exhibits simultaneous fouling reduction and release performance. The zwitterionic nanowires demonstrate >25% improvement in fouling reduction compared to state-of-the-art antifouling nanostructures, and four times higher fouling-release compared to conventional zwitterionic coatings. Fouling release is successfully achieved under a wall shear force that is four orders of magnitude lower than regular water jet cleaning. The mechanism of this simultaneous fouling reduction and release behavior is explored, and it is found that a combination of 1) a mechanical biocidal effect from the nanowire geometry, and 2) low interfacial adhesion resulting from the nanostructured hydration layer, are the major contributing factors. These findings provide insights into the design of nanostructured coatings with simultaneous fouling reduction and release. The newly established synthesis procedure for the zwitterionic nanowires opens new pathways for implementation as antifouling coatings in the maritime industry and biomedical devices.

RSA instability in mothers of preschoolers and adolescents is related to observations of supportive parenting behaviors.

Respiratory sinus arrhythmia (RSA; a measure of respiratory modulation of vagal control of heart rate) is a dynamic process. For mothers, RSA functioning has been associated with depressive symptoms and coincides with supportive parenting. However, research has largely focused on RSA suppression (i.e., difference score from rest to stress task). The present study examined depressive symptoms and supportive parenting with RSA instability-a dynamic measure of the magnitude of RSA change across a task. In two samples of mothers (N=210), one with preschoolers (Study 1: n=108, Mage=30.68years, SD=6.06, 47.0% Black, 43.0% White) and one with adolescents (Study 2: n=102, Mage=35.51, SD=6.51, 75.2% Black), RSA instability was calculated during an interaction task. In both studies, instrumental supportive parenting behaviors were negatively related to RSA instability. Findings provide preliminary support for RSA instability as an indicator of physiological dysregulation for mothers.

Global quark spin correlations in relativistic heavy ion collisions

The observation of the vector meson’s global spin alignment by the STAR Collaboration reveals that strong spin correlations may exist for quarks and antiquarks in relativistic heavy-ion collisions in the normal direction of the reaction plane. We propose a systematic method to describe such correlations in the quark matter. We classify them as local and long range quark spin correlations in the system. We show in particular that the effective quark spin correlations contain the genuine spin correlations originated directly from the dynamical process as well as those induced by averaging over other degrees of freedom. We also show that such correlations can be studied by measuring the vector meson’s spin density matrix and hyperon-hyperon and hyperon-anti-hyperon spin correlations. We present the relationships between these measurable quantities and spin correlations of quarks and antiquarks. Published by the American Physical Society 2024

Axial Coordinated Manganese(III) Porphyrin/Tetraazaporphyrin - 4-(10-phenylanthracen-9-yl)Pyridine Dyads: Self-Assembly, Structure and Spectral Properties in Ground and Excited States.

Self-assembly of new donor-acceptor systems based on (5,10,15,20-tetraphenylporphinato)manganese(III)/(5,10,15,20-tetra-4-tert-butylphenylporphinato)manganese(III)/(octakis(4-tert-butylphenyl)tetraazaporphinato)manganese(III) acetate ((AcO)MnTPP/(AcO)MnTBPP/(AcO)MnTAP) and 4-(10-phenylanthracen-9-yl)pyridine (PyAn) was studied using fluorescence spectroscopy and mass spectrometry. It was found that the coordination complexes of 1 : 1 composition (dyads) are formed in toluene. The spectral properties, the chemical structures and redox behavior of the dyads were described using 1H NMR, IR, ESR spectroscopy and cyclic voltammetry, respectively. The dynamic processes and the characteristics in the excited state of the dyads were obtained using the femtosecond transient absorption spectroscopy method. Density functional theory (DFT), time-dependent DFT methods were used to elucidate the dyad electronic structures and to establish the differences in their frontier molecular orbitals. The analysis of the lambda parameter and the distance of hole-pair interaction was indicated more favorable charge transfer between the macrocycle and the axial PyAn fragment in (AcO)(PyAn)MnTAP. The calculated values of the zero-field splitting parameters D and E/D, together with the g tensors of the lowest spin-orbit state for (AcO)MnTPP and (AcO)(PyAn)MnTPP were obtained using the combination of DFT and Multireference Perturbation Theory (CASSCF/NEVPT2) simulations. The data obtained develop the fundamental basis in the field of photovoltaics and show the prospects for the study of molecular systems of this class.

General framework for quantifying dissipation pathways in open quantum systems. II. Numerical validation and the role of non-Markovianity.

In the previous paper [C. W. Kim and I. Franco, J. Chem. Phys. 160, 214111-1-214111-13 (2024)], we developed a theory called MQME-D, which allows us to decompose the overall energy dissipation process in open quantum system dynamics into contributions by individual components of the bath when the subsystem dynamics is governed by a Markovian quantum master equation (MQME). Here, we contrast the predictions of MQME-D against the numerically exact results obtained by combining hierarchical equations of motion (HEOM) with a recently reported protocol for monitoring the statistics of the bath. Overall, MQME-D accurately captures the contributions of specific bath components to the overall dissipation while greatly reducing the computational cost compared to exact computations using HEOM. The computations show that MQME-D exhibits errors originating from its inherent Markov approximation. We demonstrate that its accuracy can be significantly increased by incorporating non-Markovianity by exploiting time scale separations (TSS) in different components of the bath. Our work demonstrates that MQME-D combined with TSS can be reliably used to understand how energy is dissipated in realistic open quantum system dynamics.