Fundamental Understanding Research Articles

In Silico Investigation of Biomechanical Response of a Human Brain Subjected to Primary Blast.

The brain response to the explosion-induced primary blast waves is actively sought. Over the past decade, reasonable progress has been made in the fundamental understanding of blast traumatic brain injury (bTBI) using head surrogates and animal models. Yet, the current understanding of how blast waves interact with human is in nascent stages, primarily due to the lack of data in human. The biomechanical response in human is critically required to faithfully establish the connection to the aforementioned bTBI models. In this work, the biomechanical cascade of the brain under a primary blast has been elucidated using a detailed, full-body human model. The full-body model allowed us to holistically probe short- (<5 ms) and long-term (200 ms) brain responses. The full-body model has been extensively validated against impact loading in the past. We have further validated the head model against blast loading. We have also incorporated the structural anisotropy of the brain white matter. The blast wave transmission, and linear and rotational motion of the head were dominant pathways for the loading of the brain, and these loading paradigms generated distinct biomechanical fields within the brain. Blast transmission and linear motion of the head governed the volumetric response, whereas the rotational motion of the head governed the deviatoric response. Blast induced head rotation alone produced diffuse injury pattern in white matter fiber tracts. The biomechanical response under blast was comparable to the impact event. These insights will augment laboratory and clinical investigations of bTBI and help devise better blast mitigation strategies.

Solvation effects on the excitation dynamics, structural and photorelaxation, quantum chemical investigation, and photophysical properties of 2D p-expanded quinoidal terthiophene (2DQTTs): Outlook from Ab-initio calculations

All dyes have different degrees of absorption. The present study delves into the intricate interplay between solvation and the photophysical behaviors of 2D p-expanded quinoidal terthiophene (2DQTT) dye compounds represented as A3, A4, and A5. In this study, a comprehensive investigation is presented, elucidating how solvation impacts excitation dynamics, ground and excited state geometry, photophysical characteristics. and photorelaxation dynamics of 2DQTTs. The energy gap data shows that the energies of the compounds increased in polar mediums and were greater for compound A3 which had ΔE values of 3.5227 eV in water, and 3.5225 eV in DMSO while compound A5 had the highest ΔE in all phases, with a ΔE value of 3.5453 eV in EtOH. Relaxation of the compounds leads to changes in the bonds and structural conformation of the 2D P-expanded quinoidal terthiophene (2DQTT) compounds as the compounds de-excite back to a lower energy level, and the photon causes a change in structural bonding (Stokes shift) in the heteroatoms which was taken into consideration. This manuscript not only advances our fundamental understanding of the interactions between solvation and molecular structure but also provides valuable insights into optimizing the performance of 2DQTT in optoelectronic devices as the compounds display a high absorption band in all phases, especially in water medial with compound A3, A4 and A5 recording absorbances of 785.32 nm, 787.13 nm, and 786.78 nm respectively, a high light harvesting efficiency LHE, great electron exciton energy and an injecting capacity (ΔGinject) greater than 0.20 eV in all phases. This work contributes significantly to the design and application of novel materials for next-generation optoelectronic technologies hence we hope that experimental research tests the studied compound towards the mentioned application.

Effect of Monovalent Cations on the Structure and Dynamics of Multimodal Chromatographic Surfaces.

While multimodal (MM) chromatography is a promising approach for purifying proteins, the lack of a fundamental understanding of how ion-ligand interactions govern selectivity limits its use in the biopharmaceutical industry. This study uses molecular dynamics simulations to study the interactions between simple monovalent cations and two commonly used structurally similar multimodal chromatography ligands, the Capto ligand and Nuvia cPrime, immobilized on the surface. On the Capto ligand surface, ion presence and type play a key role in modulating the formation of phenyl rings and carboxylate clusters. The flexible linkage attaching the Capto ligand to the self-assembled monolayer (SAM) surface allowed multiple ligands to form interactions with the small cations, while large cations interacted less strongly, following the order Li+ > Na+ > K+ > Cs+. Thus, smaller cations resulted in greater ordering on the surface and lower ion diffusivities, while larger cations resulted in less ordering and higher ion diffusivities, following the order Li+ < Na+ < K+ < Cs+. In contrast, due to the rigid attachment of Nuvia cPrime to the SAM surfaces, the cations bound less strongly and had a much smaller effect on ligand clustering or ordering. Additionally, ions in the presence of the Nuvia cPrime surface had generally greater diffusivities than those in the presence of the Capto ligand. Overall, the interaction of cations with the multimodal ligands can lead to unique configurations on the SAM that likely contribute to differential behavior in biological separations.

Unveiling heavy heterovalent doping-modulated microstructure and thermoelectric performance in bulk hybrid perovskite single crystals

Organic-inorganic hybrid metal halide perovskites have emerged as a promising candidate for low-temperature thermoelectric conversion. However, challenges remain in heavily doping bulk perovskite single crystals without phase segregation or self-doping compensation issues to increase the carrier concentration. Previous efforts to enhance their thermoelectric performance rely on photoexcitation or surface/interface doping, which is not suitable for bulk devices to work in dark. This study achieves high monovalent and trivalent doping concentrations of up to 5 % in bulk single crystals of MAPbI3 and MAPbBr3 without phase segregation or defect formation. For monovalent doping, K+ and Li+ are incorporated into the perovskite lattice as interstitials. The resulting lattice distortion/microstrain enhances the electrical conductivity by 10 ∼ 100 times of undoped samples at 420 K. Trivalent doping using SbCl3, BiBr3, and BiI3 significantly enhances the carrier concentration and electrical conductivity, up to 1012 cm−3 and 0.038 S m−1 for MAPbBr3 with 10 % BiI3 at 465 K, respectively, which is 105 times of the undoped samples and 10 times of the best reports on doped MAPbBr3. Interestingly, the Bi3+ dopant oxidizes the deep defect state Pb0, resulting in Bi+ and Pb2+ formation and contributing to the enhanced electrical conductivity. Enhanced thermoelectric figure of merit (ZT) is achieved in MAPbBr3 with 5 % BiI3 at 315 K, almost 100 times of the best reports on doped MAPbBr3. This study provides fundamental understanding of doping-modulated microstructural, charge carrier, and thermoelectric properties of hybrid halide perovskites, offering potential doping strategies to realize the theoretically predicted promising thermoelectric properties in their bulk single crystals for practical thermoelectric devices. The doping-modulated carrier transport will also guide the optimization of optoelectronic applications of halide perovskites for solar cells, light emitters, and photodetectors.

The Current Understanding of Mechanistic Pathways in Zeolite Crystallization.

Zeolite catalysts and adsorbents have been an integral part of many commercial processes and are projected to play a significant role in emerging technologies to address the changing energy and environmental landscapes. The ability to rationally design zeolites with tailored properties relies on a fundamental understanding of crystallization pathways to strategically manipulate processes of nucleation and growth. The complexity of zeolite growth media engenders a diversity of crystallization mechanisms that can manifest at different synthesis stages. In this review, we discuss the current understanding of classical and nonclassical pathways associated with the formation of (alumino)silicate zeolites. We begin with a brief overview of zeolite history and seminal advancements, followed by a comprehensive discussion of different classes of zeolite precursors with respect to their methods of assembly and physicochemical properties. The following two sections provide detailed discussions of nucleation and growth pathways wherein we emphasize general trends and highlight specific observations for select zeolite framework types. We then close with conclusions and future outlook to summarize key hypotheses, current knowledge gaps, and potential opportunities to guide zeolite synthesis toward a more exact science.

Room-temperature strong coupling in a single-photon emitter-metasurface system

Solid state single-photon sources with high brightness and long coherence time are promising qubit candidates for modern quantum technology. To prevent decoherence processes and preserve the integrity of the qubits, decoupling the emitters from their surrounding environment is essential. To this end, interfacing single photon emitters (SPEs) with high-finesse cavities is required, especially in the strong coupling regime, when the interaction between emitters can be mediated by cavity fields. However, achieving strong coupling at elevated temperatures is challenging due to competing incoherent processes. Here, we address this long-standing problem by using a quantum system, which comprises a class of SPEs in hexagonal boron nitride and a dielectric cavity based on bound states in the continuum (BIC). We experimentally demonstrate, at room temperature, strong coupling of the system with a large Rabi splitting of ~4 meV thanks to the combination of the narrow linewidth and large oscillator strength of the emitters and the efficient photon trapping of the BIC cavity. Our findings unveil opportunities to advance the fundamental understanding of quantum dynamical system in strong coupling regime and to realise scalable quantum devices capable of operating at room temperature.

Recent Advances in Iridium-based Electrocatalysts for Acidic Electrolyte Oxidation.

Ongoing research to develop advanced electrocatalysts for the oxygen evolution reaction (OER) is needed to address demand for efficient energy conversion and carbon-free energy sources. In the OER process, acidic electrolytes have higher proton concentration and faster response than alkaline ones, but their harsh strongly acidic environment requires catalysts with greater corrosion and oxidation resistance. At present, iridium oxide (IrO2 ) with its strong stability and excellent catalytic performance is the catalyst of choice for the anode side of commercial PEM electrolysis cells. However, the scarcity and high cost of iridium (Ir) and the unsatisfactory activity of IrO2 hinder industrial scale application and the sustainable development of acidic OER catalytic technology. This highlights the importance of further research on acidic Ir-based OER catalysts. In this review, recent advances in Ir-based acidic OER electrocatalysts are summarized, including fundamental understanding of the acidic OER mechanism, recent insights into the stability of acidic OER catalysts, highly efficient Ir-based electrocatalysts, and common strategies for optimizing Ir-based catalysts. The future challenges and prospects of developing highly effective Ir-based catalysts are also discussed.

Soil metabolomics - current challenges and future perspectives

Soil is an extremely complex and dynamic matrix, in part, due to the wide diversity of organisms living within it. Soil organic matter (SOM) is the fundamental substrate on which the delivery of ecosystem services depends, providing the metabolic fuel to drive soil function. As such, studying the soil metabolome (the diversity and concentration of low molecular weight metabolites), as a subset of SOM, holds the potential to greatly expand our understanding of the behaviour, fate, interaction and functional significance of small organic molecules in soil. Encompassing a wide range of chemical classes (including amino acids, peptides, lipids and carbohydrates) and a large number of individual molecules (ca. n = 105 to 106), the metabolome is a resultant (indirect) output of several layers of a biological hierarchy, namely the metagenome, metatranscriptome and metaproteome. As such, it may also provide support and validation for these “multi-omics” datasets. We present a case for the increased use of untargeted metabolomics in soil biochemistry, particularly for furthering our fundamental understanding of the functions driving SOM composition and biogeochemical cycling. Further, we discuss the scale of the challenge in terms of metabolite extraction, analysis and interpretation in complex plant-soil-microbial systems. Lastly, we highlight key knowledge gaps which currently limit our use of metabolomic approaches to better understand soil processes, including: (i) interpretation of large untargeted metabolomic datasets; (ii) the source, emission and fate of soil-derived volatile organic compounds (VOCs), (iii) assessing temporal fluxes of metabolites, and (iv) monitoring ecological interactions in the rhizosphere. While the application of metabolomics in ecosystem science is still in its relative infancy, its importance in understanding the biochemical system in relation to regulation, management and underpinning the delivery of ecosystem services is key to further elucidating the complex links between organisms, as well as the fundamental ability of the biological community to process and cycle key nutrients.

COF-Topological Quantum Material Nano-heterostructure for CO2 to Syngas Production under Visible Light.

Efficient solar-driven syngas production (CO+H2 mixture) from CO2 and H2O with a suitable photocatalyst and fundamental understanding of the reaction mechanism are the desired approach towards the carbon recycling process. Herein, we report the design and development of an unique COF-topological quantum material nano-heterostructure, COF@TI with a newly synthesized donor-acceptor based COF and two dimensional (2D) nanosheets of strong topological insulator (TI), PbBi2Te4. The intrinsic robust metallic surfaces of the TI act as electron reservoir, minimising the fast electron-hole recombination process, and the presence of 6s2 lone pairs in Pb2+ and Bi3+ in the TI helps for efficient CO2 binding, which are responsible for boosting overall catalytic activity. In variable ratio of acetonitrile-water (MeCN : H2O) solvent mixture COF@TI produces syngas with different ratios of CO and H2. COF@TI nano-heterostructure enables to produce higher amount of syngas with more controllable ratios of CO and H2 compared to pristine COF. The electron transfer route from COF to TI was realized from Kelvin probe force microscopy (KPFM) analysis, charge density difference calculation, excited state lifetime and photoelectrochemical measurements. Finally, a probable mechanistic pathway has been established after identifying the catalytic sites and reaction intermediates by in situ DRIFTS study and DFT calculation.

Fundamental structural and electronic understanding of palladium catalysts on nitride and oxide supports

The nature of the support can fundamentally affect the function of a heterogeneous catalyst. For the novel type of isolated metal atom catalysts, sometimes referred to as single‐atom catalysts, systematic correlations are still rare. Here, we report a general finding that Pd on nitride supports (non‐metal and metal nitride) always features a higher oxidation state compared to that on oxide supports (non‐metal and metal oxide). Through thorough oxidation state investigations by X‐ray absorption spectroscopy (XAS), X‐ray photoelectron spectroscopy (XPS), CO‐DRIFTS, and density functional theory (DFT) coupled with Bader charge analysis, it is found that Pd atoms prefer to interact with surface hydroxyl group to form a Pd(OH)x species on oxide supports, while on nitride supports, Pd atoms incorporate into the surface structure in the form of Pd−N bonds. Moreover, a correlation was built between the formal oxidation state and the computational Bader charge, based on the periodic trend in electronegativity.

Divergent Responses of Summer Terrestrial Evapotranspiration to Cloud Increase in East Asia

AbstractCloud impact on terrestrial evapotranspiration (ET) can be significant, while a fundamental understanding of ET response to cloud change has not been addressed in regional aspects. In this study, seven ET datasets from satellite and land surface models are used to analyze the summer ET in response to low cloud cover (LCC) over East Asia, in combination with satellite microwave and optical vegetation data, as well as ERA5 climatic and surface parameters. In general, all ET datasets present a strong negative relationship with LCC over dense vegetation (e.g., forests), which leads to the ET reduction of more than −0.5 mmday−1 under the large LCC increase, compared with the least cloudy sky conditions. Such reduction is stronger under more humid and denser forests (aridity index AI &gt; 0.5 and enhanced vegetation index EVI &gt; 0.6). In contrast, a positive relationship between ET and LCC presents over arid and sparse lands (AI &lt; 0.2 and EVI &lt; 0.2), accompanied by enhanced ET (&gt;0.2 mmday−1). Analysis shows that under increased LCC conditions, substantial reduction in radiation availability results in the decline in both plant transpiration (ETveg) and soil evaporation (ETsoil) over humid dense vegetation, dominating the overall negative response. The increase of near‐surface relative humidity over arid sparse vegetation may indicate a stronger moisture availability, which promotes ETsoil and partly offsets the negative effect of radiation reduction. The change of vegetation water content, indicated by a satellite microwave vegetation index, is important for ETveg over arid mountainous lands with cloud cover. These findings contribute new insights to the understanding of vegetation‐atmosphere interactions.

Raman scattering evolution in temperature-induced ferroelectric phase transition of few-layer NbOCl2

NbOCl2 is an emerging layered ferroelectric (FE) material with unique photoelectric properties. However, the phonons and thermal properties of NbOCl2 have remained elusive. Here, we report measurements of Raman and second harmonic generation spectrum of NbOCl2 flakes as a function of temperature (80–500 K). All observed Raman modes exhibit temperature-dependent shift. The first-order temperature coefficients of P1, P2, P3, P4, and P5 modes are 0.001 58, −0.005 21, −0.006 44, −0.012 56, and 0.036 75 cm−1 K−1, respectively. Interestingly, the frequency of the P1 mode changes directly from 161 to 156 cm−1 with increasing temperature, which is attributed to the switching between two independent Raman modes (P1H and P1L). The P1H mode is mainly contributed by the FE phase, while the P1L mode is mainly contributed by the antiferroelectric phase. Our results provide a fundamental understanding and analysis of the thermal–phonon coupling properties of few-layer NbOCl2 and promote the deep exploration of the basic physical properties of few-layer NbOCl2, which is crucial for the design and application of NbOCl2-based thermal and optoelectronic devices in the future.

Ultrafast Charge Transfer Cascade in a Mixed-Dimensionality Nanoscale Trilayer.

Innovation in optoelectronic semiconductor devices is driven by a fundamental understanding of how to move charges and/or excitons (electron-hole pairs) in specified directions for doing useful work, e.g., for making fuels or electricity. The diverse and tunable electronic and optical properties of two-dimensional (2D) transition metal dichalcogenides (TMDCs) and one-dimensional (1D) semiconducting single-walled carbon nanotubes (s-SWCNTs) make them good quantum confined model systems for fundamental studies of charge and exciton transfer across heterointerfaces. Here we demonstrate a mixed-dimensionality 2D/1D/2D MoS2/SWCNT/WSe2 heterotrilayer that enables ultrafast photoinduced exciton dissociation, followed by charge diffusion and slow recombination. Importantly, the heterotrilayer serves to double charge carrier yield relative to a MoS2/SWCNT heterobilayer and also demonstrates the ability of the separated charges to overcome interlayer exciton binding energies to diffuse from one TMDC/SWCNT interface to the other 2D/1D interface, resulting in Coulombically unbound charges. Interestingly, the heterotrilayer also appears to enable efficient hole transfer from SWCNTs to WSe2, which is not observed in the identically prepared WSe2/SWCNT heterobilayer, suggesting that increasing the complexity of nanoscale trilayers may modify dynamic pathways. Our work suggests "mixed-dimensionality" TMDC/SWCNT based heterotrilayers as both interesting model systems for mechanistic studies of carrier dynamics at nanoscale heterointerfaces and for potential applications in advanced optoelectronic systems.

An entropic theory of homogeneous ice nucleation in non-ionic aqueous solutions.

The nucleation of ice from aqueous solutions is a process essential to myriad environmental and industrial processes, but the physical factors affecting the capacity of different solutes to depress the homogeneous nucleation temperature of ice are yet poorly understood. In this work, we demonstrate that for many binary aqueous solutions of non-ionic solutes, this depression is dominated by the entropy of the liquid phase. Employing the classic Turnbull interpretation of the interfacial free energy γ∼TSliquid-Ssolid and estimating solution entropies with a Flory-style modification of the ideal entropy of mixing that accounts for solute size effects, we demonstrate that mixing entropy alone predicts experimental homogeneous nucleation temperatures across a wide variety of non-ionic solutions. We anticipate that this physical insight will not only enhance a fundamental understanding of homogeneous nucleation processes across fields but also open new avenues to the rational design of aqueous solutions for desired nucleation behaviors.

Electrogenerated Chemiluminescence Imaging of Single‐Atom Nanocatalysts

AbstractSingle‐atom catalysts (SACs), distinguished by their maximum atom efficiency and precise control over the coordination and electronic properties of individual atoms, show great promise in electrocatalysis. Gaining a comprehensive understanding of the electrochemical performance of SACs requires the screening of electron transfer process at micro/nano scale. This research pioneers the use of electrogenerated chemiluminescence microscopy (ECLM) to observe the electrocatalytic reactions at individual SACs. It boasts sensitivity at the single photon level and temporal resolution down to 100 ms, enabling real‐time capture of the electrochemical behavior of individual SACs during potential sweeping. Leveraging the direct correlation between ECL emission and heterogeneous electron transfer processes, we introduced photon flux density for quantitative analysis, unveiling the electrocatalytic efficiency of individual SACs. This approach systematically reveals the relationship between SACs based on different metal atoms and their peroxidase (POD)‐like activity. The outcomes contribute to a fundamental understanding of SACs and pave the way for designing SACs with diverse technological and industrial applications.

Electrogenerated Chemiluminescence Imaging of Single-Atom Nanocatalysts.

Single-atom catalysts (SACs), distinguished by their maximum atom efficiency and precise control over the coordination and electronic properties of individual atoms, show great promise in electrocatalysis. Gaining a comprehensive understanding of the electrochemical performance of SACs requires the screening of electron transfer process at micro/nano scale. This research pioneers the use of electrogenerated chemiluminescence microscopy (ECLM) to observe the electrocatalytic reactions at individual SACs. It boasts sensitivity at the single photon level and temporal resolution down to 100 ms, enabling real-time capture of the electrochemical behavior of individual SACs during potential sweeping. Leveraging the direct correlation between ECL emission and heterogeneous electron transfer processes, we introduced photon flux density for quantitative analysis, unveiling the electrocatalytic efficiency of individual SACs. This approach systematically reveals the relationship between SACs based on different metal atoms and their peroxidase (POD)-like activity. The outcomes contribute to a fundamental understanding of SACs and pave the way for designing SACs with diverse technological and industrial applications.

Ganglioside GM1 Drives Hemin and Protoporphyrin Adsorption in Phospholipid Membranes: A Structural Study.

Monosialoganglioside (GM1), a ubiquitous component of lipid rafts, and hemin, an integral part of heme proteins such as hemoglobin, are essential to the cell membranes of brain neurons and erythrocyte red blood cells for regulating cellular communication and oxygen transport. Protoporphyrin IX (PPIX) and its derivative hemin, on the contrary, show significant cytotoxic effects when in excess causing hematological diseases, such as thalassemia, anemia, malaria, and neurodegeneration. However, the in-depth molecular etiology of their interactions with the cell membrane has so far been poorly understood. Herein, the structure of the polymer cushion-supported lipid bilayer (SLB) of the binary mixture of phospholipid and GM1 in the presence of PPIX and its derivative hemin has been investigated to predict the molecular interactions in model phospholipid membranes. A high-resolution synchrotron-based X-ray scattering technique has been employed to explore the out-of-plane structure of the assembly at different compositions and concentrations. The structural changes have been complemented with the isobaric changes in the mean molecular area obtained from the Langmuir monolayer isotherm to predict the additive-induced membrane condensation and fluidization. PPIX-induced fluidization of phospholipid SLB without GM1 was witnessed, which was reversed to condensation with 2-fold higher structural changes in the presence of GM1. A hemin concentration-dependent linear condensing effect was observed in the pristine SLB. The effect was significantly reduced, and the linearity was observed to be lost in the mixed SLB containing GM1. Our study shows that GM1 alters the interaction of hemin and PPIX with the membrane, which could be explained with the aid of hydrophobic and electrostatic interactions. Our study indicates favorable and unfavorable interactions of GM1 with PPIX and hemin, respectively, in the membrane. The observed structural changes in both SLB and the underlying polymer cushion layer lead to the proposal of a molecule-specific interaction model that can benefit the pharmaceutical industries specialized for drug designing. Our study potentially enriches our fundamental biophysical understanding of neurodegenerative diseases and drug-membrane interactions.

Spatially and Temporally Resolved Dynamic Response of Co-Based Composite Interface during the Oxygen Evolution Reaction.

Interfacial interaction dictates the overall catalytic performance and catalytic behavior rules of the composite catalyst. However, understanding of interfacial active sites at the microscopic scale is still limited. Importantly, identifying the dynamic action mechanism of the "real" active site at the interface necessitates nanoscale, high spatial-time-resolved complementary-operando techniques. In this work, a Co3O4 homojunction with a well-defined interface effect is developed as a model system to explore the spatial-correlation dynamic response of the interface toward oxygen evolution reaction. Quasi in situ scanning transmission electron microscopy-electron energy-loss spectroscopy with high spatial resolution visually confirms the size characteristics of the interface effect in the spatial dimension, showing that the activation of active sites originates from strong interfacial electron interactions at a scale of 3 nm. Multiple time-resolved operando spectroscopy techniques explicitly capture dynamic changes in the adsorption behavior for key reaction intermediates. Combined with density functional theory calculations, we reveal that the dynamic adjustment of multiple adsorption configurations of intermediates by highly activated active sites at the interface facilitates the O-O coupling and *OOH deprotonation processes. The dual dynamic regulation mechanism accelerates the kinetics of oxygen evolution and serves as a pivotal factor in promoting the oxygen evolution activity of the composite structure. The resulting composite catalyst (Co-B@Co3O4/Co3O4 NSs) exhibits an approximately 70-fold turnover frequency and 20-fold mass activity than the monomer structure (Co3O4 NSs) and leads to significant activity (η10 ∼257 mV). The visual complementary analysis of multimodal operando/in situ techniques provides us with a powerful platform to advance our fundamental understanding of interfacial structure-activity relationships in composite structured catalysts.

A dominant negative mutation of GhMYB25-like alters cotton fiber initiation, reducing lint and fuzz.

Cotton (Gossypium hirsutum) fibers, vital natural textile materials, are single-cell trichomes that differentiate from the ovule epidermis. These fibers are categorized as lint (longer fibers useful for spinning) or fuzz (shorter, less useful fibers). Currently, developing cotton varieties with high lint yield but without fuzz remains challenging due to our limited knowledge of the molecular mechanisms underlying fiber initiation. This study presents the identification and characterization of a naturally occurring dominant negative mutation GhMYB25-like_AthapT, which results in a reduced lint and fuzzless phenotype. The GhMYB25-like_AthapT protein exerts its dominant negative effect by suppressing the activity of GhMYB25-like during lint and fuzz initiation. Intriguingly, the negative effect of GhMYB25-like_AthapT could be alleviated by high expression levels of GhMYB25-like. We also uncovered the role of GhMYB25-like in regulating the expression of key genes such as GhPDF2 (PROTODERMAL FACTOR 2), CYCD3; 1 (CYCLIN D3; 1) and PLD (Phospholipase D), establishing its significance as a pivotal transcription factor in fiber initiation. We identified other genes within this regulatory network, expanding our understanding of the determinants of fiber cell fate. These findings offer valuable insights for cotton breeding and contribute to our fundamental understanding of fiber development.

Study on Influence of Core Structure on Catalytic Converter Performance Using CFD

In recent years, as the automotive industry is growing, one of the major hope for future vehicles is to meet emissions regulations. Automobiles pollute the air, and clean-air laws have made Catalytic Converters a legal requirement because they convert harmful pollutants from an engine's exhaust into cleaner emissions. The device works with the principle of a catalyst, something that causes or speeds up a chemical reaction without itself being changed. But the presence of a catalytic converter increases the exhaust back pressure which has an indirect effect on the engine efficiency ie engine efficiency decreases, thus increasing fuel consumption. The performance of a catalytic converter is substantially affected by the flow distribution inside the substrate, a uniform flow distribution can increase its efficiency, lower the pressure drop and optimize engine performance. The flow distribution in a catalytic converter assembly 15 is governed by the geometry configurations of the inlet and outlet cone section, the substrate, and exhaust gas compositions, and therefore a better design of the catalytic converter is very important. This Project deals with the fundamental understanding and study of complex processes taking place involving fluid flow, pressure, and velocity profiles in the catalytic converter using ANSYS WORKBENCH 2022 R1. The main objective of our analysis is to determine the most effective and optimum design of a Catalytic Converter