Role Of Structure Research Articles

Water Oxidation in the Presence of Iron-Doped Copper (Hydr)Oxide.

This study explores the influence of Fe ion incorporation on the oxygen-evolution reaction (OER) in alkaline media, utilizing CuO-based materials. Instead of developing an efficient and stable OER catalyst, this research investigates two distinct CuO variants: one with Fe ions adhered to the surface and another with Fe ions integrated into the CuO lattice. By employing a variety of analytical techniques, the study demonstrates that the CuO variant with surface-bound Fe ions (referred to as compound 1) exhibits significantly enhanced OER performance compared to the variant with internally embedded Fe ions (referred to as compound 2). The Tafel plots obtained from multistep amperometry profiles for compounds 1 and 2, as well as pure CuO and FeO(OH), exhibit linear relationships in the log(j) vs overpotential plot, with Tafel slopes of 39.3, 41.5, 115.9, and 121.9 mV/decade, respectively. These Tafel slopes indicate that compounds 1 and 2 likely share a similar reaction mechanism, whereas CuO and FeO(OH) appear to follow distinct mechanisms. At 570 mV overpotential, the turnover frequencies of Fe ions for compounds 1 and 2, as well as for FeO(OH), calculated from electrode compositions and chronoamperometry data, are found to be 1.1, 0.2, and 5.7 × 10-4 s-1, respectively. Despite the differing distributions of Fe ions, both CuO variants exhibit similar Tafel slopes, suggesting that they follow comparable OER mechanisms. Additionally, cyclic voltammetric profiles, corrected for the electrochemically active surface area, indicate that FeO(OH) demonstrates notably higher activity than the other compounds. These findings deepen our understanding of Fe's role in CuO structures for OER processes and offer valuable insights for the design of more efficient electrocatalytic materials in alkaline environments.

Predator–Prey Movement Interactions: Jaguars and Peccaries in the Spotlight

ABSTRACTUnderstanding how landscape structure influences predator–prey dynamics is critical for conservation. This study analyzed jaguar‐peccary interactions, revealing uncommon close distances and prevalent 3–5 km ranges, especially away from grasslands. Low peccary densities increased interactions. Findings inform conservation strategies, highlighting landscape structure and prey density roles in maintaining Pantanal's balance.

Cation-Cation Interaction in Np(V) Perchlorates and Their Electronic Absorption Spectra.

Four new Np(V) perchlorate complexes of the composition [NpO2(H2O)4]ClO4 (orthorhombic) (1), [(NpO2)2(ClO4)(H2O)4]ClO4·H2O (3), [(NpO2)(UO2)(H2O)8](ClO4)3 (4), and [(NpO2)2Cl(H2O)4]ClO4·2H2O (5) have been synthesized and structurally characterized. The structure of previously known monoclinic modification of NpO2ClO4·4H2O (2) has been determined at 100 K. The coordination environment of Np and U atoms in compounds 1-5 is pentagonal bipyramids. A cation-cation (CC) interaction was found in structures 1-5, in which the NpO2+ ion manifests itself as a monodentate (1, 2) or bidentate (3-5) ligand. CC bonds play a fundamental role in the crystal structures of compounds 1, 2, and 4. They are the main structure-forming bonds that form the crystal package as a whole. The spectra of all compounds in the visible-near-IR range were measured.

Targeting HMGB1 and Its Interaction with Receptors: Challenges and Future Directions.

High mobility group box 1 (HMGB1) is a nonhistone chromatin protein predominantly located in the nucleus. However, under pathological conditions, HMGB1 can translocate from the nucleus to the cytoplasm and subsequently be released into the extracellular space through both active secretion and passive release mechanisms. The distinct cellular locations of HMGB1 facilitate its interaction with various endogenous and exogenous factors, allowing it to perform diverse functions across a range of diseases. This Perspective provides a comprehensive overview of the structure, release mechanisms, and multifaceted roles of HMGB1 in disease contexts. Furthermore, it introduces the development of both small molecule and macromolecule inhibitors targeting HMGB1 and its interaction with receptors. A detailed analysis of the predicted pockets is also presented, aiming to establish a foundation for the future design and development of HMGB1 inhibitors.

Algorithmic Management. Theoretical Perspectives and Implications for Organizational Development

Algorithmic management leverages data-driven algorithms and artificial intelligence to automate managerial functions traditionally executed by human managers. This paper provides a comprehensive overview of algorithmic management, exploring its definitions and emergence in gig economy platforms and traditional workplaces. It delves into key sociological and organizational theories—including Weber's bureaucracy, Critical Management Studies (CMS), and technological rationality—to frame the discussion. The impact of algorithmic management on employee autonomy, digital surveillance, and forms of worker resistance is examined, alongside its role in shaping organizational structures, enhancing efficiency, and driving innovation. Ethical implications, particularly concerning fairness, transparency, and bias, are critically analyzed. While algorithmic management offers potential benefits such as improved efficiency and decision-making, it also raises significant concerns about worker autonomy, power imbalances, and ethical considerations. The paper underscores the need for a nuanced understanding and responsible implementation of algorithmic management to harness its advantages while mitigating its drawbacks.

Expanding the Toolset of Biomolecular NMR with Efficient and Cost-Effective 17O-Labeling via Bacterial Expression.

Oxygen plays a central role in biomolecular structures and functions, with 17O NMR emerging as a powerful tool for elucidating biomolecular properties. However, the low natural abundance of the NMR-active isotope, 17O (0.0373 %), presents a significant hurdle to its widespread application. Here, we introduce a rapid and cost-effective approach for amino acid-specific 17O-labeling of recombinant proteins. Using a common bacterial expression system and with a 30-minute rapid synthesis protocol of 17O-labeled amino acids via mechanochemical saponification, we have generated Leu- and Phe-specific 17O-labeled recombinant proteins derived from diverse organisms, including CrgA and FtsQ from Mycobacterium tuberculosis and E protein from SARS-CoV-2 virus, demonstrating the applicability of our technique for amino acids known to be isotopically labeled without scrambling. We have acquired magic-angle-spinning 17O NMR of these proteins to confirm the successful 17O labeling and illustrate the sensitivity of 17O NMR to the protein's local structural environments. Our work significantly broadens the accessibility of 17O-NMR, empowering researchers to delve deeper into protein biophysics and biochemistry. This approach opens new avenues for understanding cellular processes at the molecular level by providing an effective tool for investigating oxygen-related interactions and chemistry within biomolecules.

Energy price shocks and current account balances: what role for economic structure, energy dependency and renewable energy development?

Energy price shocks and current account balances: what role for economic structure, energy dependency and renewable energy development?

Multicomponent Synthesis of Structurally Diverse Spiroheterocycles using Bio-organic Catalyst in Aqueous Medium

Background: MCRs are one of the most significant tools in the synthesis of organic compounds. MCR is a rapid chemical technique that uses three or more reactants to produce products that sustain all structural and substructural properties of the initial components. MCRs are useful in all fields of synthetic chemistry because of their rapid rate of reaction, simple procedure and excellent yields. We reported an efficient and environmentally friendly domino approach for the synthesis of spiroheterocycles spiro annulated with indeno[1,2-b]quinoline. Method: The spiroheterocycles with privileged heterocyclic substructures have been synthesized using taurine (2-aminoethanesulfonic acid) as a green, sustainable, bio-organic and recyclable catalyst in a three-component reaction of isatins, 1,3-diketones, and 1-napthylamine in aqueous media. The present synthetic method is probably the first report to synthesize spiroheterocycles, spiroannulated with indeno[1,2-b]quinoline. Furthermore, the approach is valuable because of the excellent yield that results from the reaction in 15-20 min. Result: The optimization of reaction conditions is an important case of efficient synthesis. The solvent, temperature, time and catalyst loading were all examined. The reusability of the catalyst was also investigated experimentally. The used catalyst taurine has a high activity as well as good reusability. The present synthetic protocol will be extended to synthesise a library of hybrid compounds. The present synthetic approach is cost-effective, and time-efficient with an easy-workup methodology that gives outstanding yields (80–95%) in 15–20 min. Conclusion: Taurine-catalyzed multicomponent reaction is a novel and efficient method for the synthesis of spiroannulated indeno[1,2-b]quinolines. The high catalytic activity of taurine as a catalyst with water as a green solvent makes the process environmentally friendly. The special features of the synthetic protocol include synthetic efficiency, operational simplicity, and reusability of the catalyst and it is expected to make significant contributions not only to drug discovery studies but also to pharmaceutical and therapeutic chemistry in view of introducing molecular diversity in the synthesized molecules.

Chiroptical Response of Carbon Nanocages Enhanced by Achiral Guests

Opening up [60]fullerene makes itself inherently chiral without loss of congenital π‐conjugation. An immoderately large aperture on [60]fullerene, however, renders the molecule less rigid and therefore it would reduce dissymmetry factors. Herein, we examined supramolecular technique in geometrical reinforcement of chiral open‐[60]fullerenes by encasing achiral guests such as Ar,‐CO2, and CH3CN. At a lowest‐energy transition, we confirmed a guest‐dependency on chiroptical responses with increasing a dissymmetry factor by nearly twice to three times. It should be noted that the guests play a negligible role in electronic structures of the carbon cages. Instead, they are engaged in preclusion of an orifice shrinking not to reduce chiroptical response.

Chiroptical Response of Carbon Nanocages Enhanced by Achiral Guests.

Opening up [60]fullerene makes itself inherently chiral without loss of congenital π-conjugation. An immoderately large aperture on [60]fullerene, however, renders the molecule less rigid and therefore it would reduce dissymmetry factors. Herein, we examined supramolecular technique in geometrical reinforcement of chiral open-[60]fullerenes by encasing achiral guests such as Ar, CO2, and CH3CN. At a lowest-energy transition, we confirmed a guest-dependency on chiroptical responses with increasing a dissymmetry factor by nearly twice to three times. It should be noted that the guests play a negligible role in electronic structures of the carbon cages. Instead, they are engaged in preclusion of an orifice shrinking not to reduce chiroptical response.

Aspect ratio-dependent etching in silicon using XeF2: experimental investigation and comparative analysis with dry etching methods

Abstract Silicon machining plays a crucial role in shaping three-dimensional structures for Micro-Electro-Mechanical Systems (MEMS) applications. This study investigates Aspect Ratio Dependent Etching (ARDE) across various silicon etching processes, with a particular focus on Xenon Difluoride (XeF2) etching, in comparison to Reactive Ion Etching (RIE) and Deep Reactive Ion Etching (DRIE).By exploring different etching parameters, the study highlights the presence of ARDE in both plasma and non-plasma etching processes. Additionally, it is demonstrated that ARDE can be modeled by a saturating exponential function through experimental adjustment of parameters, enabling the prediction of etching profiles.

Harnessing Extrinsic Dissipation to Enhance the Toughness of Composites and Composite Joints: A State-of-the-Art Review of Recent Advances.

Interfaces play a critical role in modern structures, where integrating multiple materials and components is essential to achieve specific functions. Enhancing the mechanical performance of these interfaces, particularly their resistance to delamination, is essential to enable extremely lightweight designs and improve energy efficiency. Improving toughness (or increasing energy dissipation during delamination) has traditionally involved modifying materials to navigate the well-known strength-toughness trade-off. However, a more effective strategy involves promoting non-local or extrinsic energy dissipation. This approach encompasses complex degradation phenomena that extend beyond the crack tip, such as long-range bridging, crack fragmentation, and ligamentformation. This work explores this innovative strategy within the arena of laminated structures, with a particular focus on fiber-reinforced polymers. This review highlights the substantial potential for improvement by presenting various strategies, from basic principles to proof-of-concept applications. This approach represents a significant design direction for integrating materials and structures, especially relevant in the emerging era of additive manufacturing. However, it also comes with new challenges in predictive modeling of such mechanisms at the structural scale, and here the latest development in this direction is highlighted. Through this perspective, greater durability and performance in advanced structural applications can beachieved.

Predicting co-crystal structures of N-halide phthalimides with 3,5-dimethylpyridine.

Crystal structure prediction (CSP) calculations were carried out to examine potential formation of co-crystals between N-halide phthalimides (Cl, Br or I) and 3,5-dimethylpyridine (35DMP). The co-crystal structure of N-bromophthalimide (nbp) with 35DMP (nbp-35DMP) is known, and the generated co-crystal structure of rank 1 is identical to experimental structure (VELXES). For the unknown crystal structure of N-iodophthalimide (nip), structure of rank 1 is suggested as a likely co-crystal structure. On the other hand, our calculations suggest the improbability of co-crystal formation between ncp and 35DMP. The CSP findings indicate that strong N-X...N interactions consistent with similar experimental structures in the Cambridge Structural Database play a major role in crystal structures of the studied compounds.

The role of ATP-binding Cassette subfamily B member 6 in the inner ear

ABCB6 has been implicated in dyschromatosis universalis hereditaria, a condition characterized by hyperpigmented and hypopigmented skin macules. Dyschromatosis universalis hereditaria can also present with hearing loss. Dyschromatosis universalis hereditaria-associated mutations in ABCB6 have been reported, but the role of this protein in the inner ear has not been studied. Here we determine a high-resolution (2.93 Å) cryo-EM structure of ABCB6 and functionally characterized several dyschromatosis universalis hereditaria mutants. We find that the L356P mutant abolishes ABCB6 function, and affirm the underlying loss of ATP binding mechanism using molecular dynamics simulations based on our cryo-EM structure. To test the role of ABCB6 in the inner ear, we characterize Abcb6 (the ABCB6 homolog) in zebrafish. We show that Abcb6 suppression by morpholinos reduces inner ear and lateral line hair cell numbers. Morphants also lack the utricular otolith, which is associated with vestibular function. Co-injecting morpholinos with human ABCB6 mRNA partially rescues the morphant phenotype, suggesting that Abcb6 plays a developmental role in inner ear structures. Further, we show that Abcb6 knockout mice exhibit an increased auditory brainstem response threshold, resulting in reduced hearing sensitivity. Taken together, these data suggest ABCB6 plays a role in inner ear development and function.

A Poly(2,7‐anthrylene) with peri‐Fused Porphyrin Edges

AbstractAnthracene has served as an important building block of conjugated polymers with the connecting positions playing a crucial role for the electronic structures. Herein, anthracene units have been coupled through their 2,7‐carbons to develop an unprecedented, conjugated polymer, namely, poly(2,7‐anthrylene) featuring additional peri‐fused porphyrin edges. The synthesis starts from a 2,7‐dibromo‐9‐nickel(II) porphyrinyl‐anthracene as the pivotal precursor. Polymerization is achieved by an AA‐type Yamamoto coupling, followed by a polymer‐analogous oxidative cyclodehydrogenation to obtain a peri‐fusion between porphyrin and anthracene moieties. Although further cyclodehydrogenation between the repeating units cannot be achieved in solution, the thermal treatment of the precursor polymer derived from 2,7‐dibromo‐9‐porphyrinyl‐anthracene on a metal surface realizes the full cyclodehydrogenation. The difference between solution and on‐surface reactivity can be rationalized by the larger dihedral angle between repeat units in solution, which is reduced under the pronounced interaction with the metal surface. The peri‐fusion in the title polymer gives rise to a narrow electronic band gap optical absorptions extending far into the near‐infrared region. Oligomeric models are synthesized as well to support the analyses of the electronic and photophysical properties.

Mapalus as a Socio-Cultural System in Minahasa Society

This study aims to examine Mapalus as a socio-cultural system in Minahasa society, with a focus on an in-depth understanding of its historical roots, core values, roles in social structures, and adaptations and challenges faced in the modern era. The method used is a qualitative approach with a literature review type of research, involving a comprehensive analysis of various literature sources including books, journal articles, historical documents, and publications related to Mapalus and Minahasa culture. The results of the study indicate that Mapalus is a mutual cooperation system that has been deeply rooted in Minahasa society since ancient times, reflecting the values of cooperation, solidarity, and reciprocity. Mapalus has been shown to have an important role in the formation of social cohesion, resource management, and local economic development. Despite facing the challenges of modernization, Mapalus shows adaptability, evolution of form, and potential as a development model based on local wisdom. This study concludes that Mapalus remains relevant and has the potential to be a source of inspiration for the development of sustainable community-based development models.

Implementation of Convergence (Cross-Sectoral) Action for the Acceleration of Stunting Reduction in Palopo City, South Sulawesi, Indonesia

Background: The global trend of stunting incidence has been declining from 2000 to 2022; however, the WHO still categorizes Indonesia as a country with a very high prevalence of stunting. A multisectoral and multi-stakeholder approach is one of the methods utilized in the National Action Plan for Accelerating Stunting Reduction. This study aims to analyze the implementation of convergence actions for accelerating stunting reduction in Palopo City. Methods: The study was conducted for 1 months in Palopo City. This study was a qualitative study with 14 informants from different regional government agencies (OPDs) involved in the Palopo City Stunting Reduction Task Force (TPPS). Data related to the implementation convergence action for Accelerating Stunting Reduction in Palopo City owere obtained through in-depth interviews. Qualitative data were processed by searching for keywords and then content analysis was conducted. Qualitative data analysis uses an inductive thinking process. Results: The study reveals that at the initial stage, each OPD recognizes the importance of cross-sectoral participation. However, challenges persist in the utilization of human resources and budgeting. The collaboration process requires improvements as planning, governance structure, and actor roles are not yet optimal, with some OPDs still lacking clarity on their roles. Leadership in Palopo City involves regulation and communication, yet some OPDs lack specific Standard Operating Procedures (SOPs) and regulations, though inter-agency communication is fairly effective. The outputs of stunting interventions focus on health, education, infrastructure, and social welfare, with some programs being directly integrated while others provide indirect support. Conclusion: The implementation of convergence actions for accelerating stunting reduction in Palopo City is not yet optimal, with primary challenges in the utilization of human resources and budgeting. The collaboration process, leadership, and program outputs still require improvement, particularly in planning, governance structure, and inter-agency communication.

Prograde and retrograde stars in nuclear cluster merger. Evolution of the supermassive black hole binary and the host galactic nucleus

Nuclear star cluster (NSC) mergers, involving the fusion of dense stellar clusters near the centres of galaxies, play a pivotal role in shaping galactic structures. The distribution of stellar orbits has significant effects on the formation and characteristics of extreme mass ratio inspirals (EMRIs). In this study, we address the orbital distribution of stars in merging NSCs and the subsequent effects on supermassive black hole binary (SMBHB) evolution. We ran dedicated direct-summation $N$-body simulations with different initial conditions to do a detailed study of the resulting NSC after their progenitors had merged. Our findings reveal that prograde stars form a flattened structure, while retrograde stars have a more spherical distribution. The axial ratios of the prograde component vary based on the presence and mass ratio of the SMBHs. The fraction of prograde and retrograde stars depends on the merger orbital properties and the SMBH mass ratio. The interactions of retrograde stars with the SMBHB affect the eccentricity and separation evolution of the binary. Our analysis reveals a strong correlation between the angular momentum and eccentricity of the SMBH binary. This relationship could serve as a means to infer information about the stellar dynamics surrounding the binary. We find that prograde orbits are particularly close to the binary of SMBHs, a promising fact regarding EMRI production. Moreover, prograde and retrograde stars have different kinematic structures, with the prograde stars typically rotating faster than the retrograde ones. The line-of-sight velocity and velocity dispersion, as well as the velocity anisotropy of each NSC, depend on the initial merger orbital properties and SMBH mass ratios. The prograde and retrograde stars always show different behaviours. The distribution of stellar orbits and the dynamical properties of each kinematic population can potentially be used as a way to tell the properties of the parent nuclei apart, and has an important impact on expected rates of EMRIs, which will be detected by future gravitational wave observatories such as the Laser Interferometer Space Antenna (LISA).

Effects of tree species identity on soil microbial communities in Juglans nigra and Quercus rubra plantations.

Understanding how different tree species affect soil microbial communities is crucial for sustainable forestry and ecosystem management practices. Despite Black walnut (Juglans nigra L.) forestry having a rich history, the overall comprehension of how this hardwood species influences soil remains incomplete. In earlier studies, we examined the effects of hardwood plantations on soil chemical properties and their interaction with microbial biomass, however, we highlight the importance of studying the soil microbial communities and their relationship with soil properties in greater depth. Building on this foundation, our research focused on evaluating microbiome compositions beneath J. nigra and another hardwood, Northern red oak (Quercus rubra L.) after a decade of establishment. We uncovered intriguing patterns within the soil bacterial/archaeal and fungal structures by conducting meticulous analyses utilizing amplicon sequencing alongside soil chemical properties. Our findings underscore that tree species play a pivotal role in shaping soil microbial structures, a role that surpasses even seasonal and depth influences. Most notably, J. nigra stands out for its ability to enhance microbial diversity, as evidenced by increased alpha-diversity indices compared to baseline values. Conversely, Q. rubra tends to decrease these indices. Significant disparities in microbial composition between the two tree species were evident, with J. nigra exhibiting enrichment in certain taxa such as Nitrospira, Geobacter, and Bacillus while Q. rubra showed enrichment in others like Acidobacteriota and ectomycorrhizal fungi. Furthermore, we also observed differences in co-occurrence networks by delving deeper into the interconnections within the soil microbiota. In both fungal and bacterial/archaeal communities, J. nigra and Q. rubra notably decreased the number of connections within their networks, while Q. rubra increased some, suggesting a more interconnected network. These differences were further highlighted by network metrics with Q. rubra displaying a higher mean degree and clustering coefficient. Additionally, our analysis revealed that tree species influence soil chemical properties, either directly or indirectly, thereby affecting soil bacterial and fungal communities. In conclusion, our study elucidates the intricate interplay between tree species and soil microbiota, emphasizing the need to consider these relationships in forestry and ecosystem management practices.

A Poly(2,7-anthrylene) with peri-Fused Porphyrin Edges.

Anthracene has served as an important building block of conjugated polymers with the connecting positions playing a crucial role for the electronic structures. Herein, anthracene units have been coupled through their 2,7-carbons to develop an unprecedented, conjugated polymer, namely, poly(2,7-anthrylene) featuring additional peri-fused porphyrin edges. The synthesis starts from a 2,7-dibromo-9-nickel(II) porphyrinyl-anthracene as the pivotal precursor. Polymerization is achieved by an AA-type Yamamoto coupling, followed by a polymer-analogous oxidative cyclodehydrogenation to obtain a peri-fusion between porphyrin and anthracene moieties. Although further cyclodehydrogenation between the repeating units cannot be achieved in solution, the thermal treatment of the precursor polymer derived from 2,7-dibromo-9-porphyrinyl-anthracene on a metal surface realizes the full cyclodehydrogenation. The difference between solution and on-surface reactivity can be rationalized by the larger dihedral angle between repeat units in solution, which is reduced under the pronounced interaction with the metal surface. The peri-fusion in the title polymer gives rise to a narrow electronic band gap optical absorptions extending far into the near-infrared region. Oligomeric models are synthesized as well to support the analyses of the electronic and photophysical properties.