Structural Perspective Research Articles

Construction of Br-Cu2O@NiFe-LDHs Z-scheme heterojunction and photocatalytic degradation of catechol

Facet regulation and construction of heterojunctions are important means to enhance the photocatalytic performance of single-phase materials. In this paper, the facet index of Cu2O was changed through Br doping, and then a Br doped Cu2O@NiFe-LDHs Z-scheme heterojunction (BC@LDHs) was constructed for photocatalytic degradation of catechol. The optimal conditions for photocatalytic degradation reaction were explored; the kinetic and thermodynamic parameters of the reaction, as well as the stability and reusability of the material were studied. Under optimal reaction conditions, the photocatalytic degradation of catechol can reach up to 95.68 % by BC@LDHs, which is much higher than that of single-phase materials and Cu2O@LDHs. By combining experiments and theoretical calculations, the intrinsic reasons and mechanisms for Br doping to enhance the photocatalytic degradation performance of BC@LDHs Z-scheme heterojunctions were fully explored from the perspectives of band structure and oxygen adsorption, determination of built-in electric field in Z-scheme heterojunctions, calculation of built-in electric field strength and bulk charge separation efficiency. This work proposes the insights that using Br doping to alter exposed facets and regulate the strength of the built-in electric field in Br-Cu2O@NiFe-LDHs heterojunctions, thereby promoting its efficient photocatalytic degradation.

How Natural Enzymes and Synthetic Ribozymes Generate Methylated Nucleotides in RNA.

Methylation of RNA nucleotides represents an important layer of gene expression regulation, and perturbation of the RNA methylome is associated with pathophysiology. In cells, RNA methylations are installed by RNA methyltransferases (RNMTs) that are specialized to catalyze particular types of methylation (ribose or different base positions). Furthermore, RNMTs must specifically recognize their appropriate target RNAs within the RNA-dense cellular environment. Some RNMTs are catalytically active alone and achieve target specificity via recognition of sequence motifs and/or RNA structures. Others function together with protein cofactors that can influence stability, S-adenosyl-L-methionine binding, and RNA affinity as well as aiding specific recruitment and catalytic activity. Association of RNMTs with guide RNAs represents an alternative mechanism to direct site-specific methylation by an RNMT that lacks intrinsic specificity. Recently, ribozyme-catalyzed methylation of RNA has been achieved in vitro, and here, we compare these different strategies for RNA methylation from structural and mechanistic perspectives.

Implications of the stigma of mental illness for professional knowledge development and practice: An Interprofessional Health Education framework from structural violence perspectives

AbstractPersons with mental illness (PWMI) continue to encounter stigma from the public with negative outcomes. Recent stigma discourse points to power differentials as key in shaping stigma related to mental illness within social settings. The perceived social injustice towards PWMI is known to exist both anecdotally and in documented discourses. Stigma constitutes the product of public attitudes and behaviors that characterize labeling, stereotyping, prejudice, cognitive separation, status loss, and discrimination that lead to responses that may include stress and esteem‐related appraisal of experienced, anticipated, perceived, or personal endorsement of societal actions that are anchored by existing power relational differentials. The potential consequence of such societal injustices (unfair treatments) towards PWMI may result in stigma and its sequels, including low socioeconomic status, stress, low self‐esteem, unemployment, homelessness, exclusion, and human rights abuse. This paper proposes an Interprofessional Health Education framework and discusses the implications of such unfair social treatments for Professional knowledge development and practice among healthcare professionals, with the view to improving collaboration and patient care outcomes. A more collaborative model of care, where service users and clinicians regard each other as knowledgeable with shared power to achieve healthy outcomes, empowers patients even more in areas where they fall short.

Structural Perspectives on Organizational Sustainability

Structural Perspectives on Organizational Sustainability

Artistic mutilation of genitalia: an interpretive analysis of representations of genitalia in Indian school science textbooks

ABSTRACT Visual representations (and their censorship) are carriers of messages and are powerful tools to invoke discourses. Visuals are not just supplements to written text; rather, these can be read independently as the primary text and are crucial to scientific communication, particularly in life sciences. This paper aims to investigate various textbook depictions of genitalia and examine how ideologies are manifested through visuals in relation to the human body. Here we try to unpack the visual representations of genitalia in different discursive spaces within Indian science textbooks from 6th to 12th grade. We position our study within the hermeneutic methodological landscape and apply the socio-semiotic analytic framework developed by Serafini [Serafini, Frank. 2010. “Reading Multimodal Texts: Perceptual, Structural and Ideological Perspectives.” Children's Literature in Education 41 (2): 85–104. https://doi.org/10.1007/s10583-010-9100-5], consisting of three analytic perspectives: perceptual, structural, and ideological, to interpret the visual images of genitalia and the ideological matrix that produced these images. Our analysis of textbooks' portrayal reveals a tendency to censor or obscure genital depictions. The paper discusses the potential effects of these representations on students' health and relationships with their bodies and argues that they must engage in dialogue with discourses challenging normative understandings of the body and remain open to change.

The Phase Equilibria of Natural Gas Hydrate in the Presence of 1,3-Dimethylcyclohexane and Octyl-β-D-glucopyranoside.

The thermodynamic effect of octyl-β-D-glucopyranoside (OGP) on the formation of methane-1,3-dimethylcyclohexane (DMCH) hydrate was studied in this work. The thermodynamic equilibrium hydrate formation pressures between 275.15 K and 283.15 K were measured by the isothermal pressure search method. Different OGP aqueous solutions (0, 0.1, and 1 wt%) were used in this work. The experimental results show that OGP had no obvious thermodynamic inhibition on methane-DMCH hydrate formation when its concentration was low (0.1 wt%), whereas it had an inhibition on methane-DMCH hydrate formation when its concentration was high (1 wt%). The phase equilibrium hydrate formation pressure of the methane-DMCH-OGP system is about 0.1 MPa higher than that of the methane-DMCH system. The dissociation enthalpies of methane hydrate in different solutions remained uniform, which indicates that OGP was not involved in methane-DMCH hydrate formation. This phenomenon is explained from the perspective of the molecular structure of OGP. As a renewable and biological nonionic surfactant, the concentration of OGP in the liquid phase is low, so OGP can be added to the methane-DMCH system without significant thermodynamic inhibition.

Potassium persulfate enhances humification of chicken manure and straw composting: The perspective of rare and abundant microbial community structure and ecological interactions

Improper disposal of organic solid waste results in serious environmental pollution. Aerobic composting provides an environmentally friendly treatment method, but improving humification of raw materials remains a challenge. This study revealed the effect of different concentrations of potassium persulfate (PP) on humification of chicken manure and straw aerobic composting and the underlying microbial mechanisms. The results showed that when 0.6 % PP was added (PPH group), humus and the degree of polymerization were 80.77 mg/g and 2.52, respectively, which were significantly higher than those in 0.3 % PP (PPL group). As the concentration of PP was increased, the composition of rare taxa (RT) changed and improved in evenness, while abundant taxa (AT) was unaffected. Additionally, the density (0.037), edges (3278), and average degree (15.21) in the co-occurrence network decreased compared to PPL, while the average path (4.021) and modularity increased in PPH. This resulted in facilitating the turnover of matter, information, and energy among the microbes. Interestingly, cooperative behavior between microorganisms during the maturation period (24–60 d) occurred in PPH, but competitive relationships dominated in PPL. Cooperative behavior was positively correlated with humus (p < 0.05). Because the indices, such as higher degree, betweenness centrality, eigenvector centrality, and closeness centrality of the AT, were located in the microbial network center compared to RT, they were unaffected by the concentration of PP. The abundance of carbohydrate and amino acid metabolic pathways, which play an important role in humification, were higher in PPH. These findings contribute to understanding the relative importance of composition, interactions, and metabolic functionality of RT and AT on humification during chicken manure and straw aerobic composting under different concentrations of PP, as well as provide a basic reference for use of various conditioning agents to promote humification of organic solid waste.

Strategy for sustainable supply chain transformation: a resource orchestration perspective

PurposeWith the popularization of sustainable concepts, how to transform into a sustainable supply chain has received widespread attention in practice. Under this circumstance, this paper aims to propose a theoretical framework of sustainable supply chain transformation (SSCT) from a perspective of resource identification and utilization, investigates resources/capabilities that can be used to promote SSCT and explores how to use resources/capabilities to achieve SSCT effectively.Design/methodology/approachAn inductive multi-case analysis is applied to this paper. Four state-owned/non-state-owned enterprises from the manufacturing sector are selected as the research objectives, which are all leaders in the industry based on the 2022 China TOP 500 Enterprises Ranking. Meanwhile, to guarantee the diversities of enterprises, the four selected enterprises are respectively positioned in upstream and downstream of the supply chain.FindingsA theoretical framework of SSCT is proposed with following research findings: (1) Technology resources, facilities and equipment resources, and business process reengineering capability are the key resources/capabilities to promote SSCT. (2) From the supply chain structure perspective, there exists a leader-participant structure in SSCT. The enterprise with dominant resources/capabilities should actively transfer to a SSCT leader. From the supply chain function perspective, specific sustainability assessment indicators and special teams are two necessary settings for SSCT. From the supply chain lifecycle perspective, SSCT should be promoted in a phased manner and dynamically adjusted in each stage. (3) Digital transformation degree and enterprise ownership play a moderating role in the implementation of strategies.Originality/valueThis paper proposes a conceptual framework of SSCT based on the resource orchestration perspective, which provides decision support for enterprises in practice.

Imaging the Lung in ARDS: A Primer.

Despite periodic changes in the clinical definition of ARDS, imaging of the lung remains a central component of its diagnostic identification. Several imaging modalities are available to the clinician to establish a diagnosis of the syndrome, monitor its clinical course, or assess the impact of treatment and management strategies. Each imaging modality provides unique insight into ARDS from structural and/or functional perspectives. This review will highlight several methods for lung imaging in ARDS, emphasizing basic operational and physical principles for the respiratory therapist. Advantages and disadvantages of each modality will be discussed in the context of their utility for clinical management and decision-making.

Optimal Dosage and Session Structure of Mindfulness-Based Programming for Youth Across Developmental Periods: Delphi Approach Outcomes

Purpose Research of mindfulness-based programming/interventions (MBP) for youth has proliferated in recent years; however, heterogeneity of MBP for youth impede determination of optimal programmatic structure across developmental periods. Design/Approach/Methods Expert MBP scientists and instructors were iteratively surveyed using the Delphi method to assess optimal MBP session structure across developmental periods. Findings Survey Round 1 defined the participants’ perspective of ideal structure across early childhood, middle childhood, and adolescence. In Survey Rounds 2 and 3, participants considered the preceding Round's results (means and SDs) and indicated what they believed was the ideal structure of a single MBP class. Final results following the Round 3 survey indicated that MBP session period should be progressively longer relative to the developmental time period (early childhood mean = 20.0 min; middle childhood mean = 34.5 min; adolescence mean = 50.0 min); that roughly half of a youth MBP session should be dedicated to mindfulness practice; and that progressively more time should be allocated to didactic instruction and discussion, relative to mindfulness practice, as youth become older. Originality/Value These findings are the first to report expert feedback on the ideal structure of a youth MBP session, and results have significant implications for future youth MBP evaluation, implementation, and curriculum development.

Numerical Investigation on the Effects of Gap Circulating Flow on Blower Performance under Design and Off-Design Conditions

Blowers are widely used in tasks such as ventilation, exhaust, drying, cooling, heat dissipation, or conveying medium, and they usually consume a lot of energy. There is an inevitable gap between the rotating impeller and static volute casing due to manufacturing tolerance and thermal deformation. The circulating flow in the gap has an important effect on the performance of the blower. In this study, computational fluid dynamics (CFD) was used to investigate the performance of the blower under different flow conditions and gaps, and the accuracy of the numerical simulation was verified by performance experiments. The results show that the flow separation under low flow conditions in the impeller channel can be suppressed by the circulating flow. However, the efficiency of the blower is decreased because a part of the power is used to maintain the circulating flow. Under design conditions, efficiency is reduced by 5.3~8.2%, depending on the gap sizes. Due to the increased flow rate in the impeller channel caused by the gap circulating flow, the net flow rate of the impeller under design conditions is about 12% higher than the inlet flow rate of the blower. Therefore, it leads to an increase of about 12% in impeller efficiency calculated by the net flow rate compared with the inlet flow rate. Finally, the flow field distribution on the impeller channel under different gap conditions was compared, and the effects of the gap on the blower performance were analyzed from the perspective of flow field structure.

Unraveling Thermal Depolarization Phenomena in Biphasic Polarized Calcium Phosphate Catalyst

AbstractPermanently polarized biphasic calcium phosphate composed of hydroxyapatite and brushite (pp‐HAp/Bru), which is prepared by applying the thermally stimulated polarization treatment to calcined HAp, is used as a sustainable catalyst to transform CO2 into value‐added products. In this work, the stability of pp‐HAp/Bru is studied from structural, electrical, and catalytic perspectives, applying a thermal depolarization process with temperatures (Td) ranging from 200 to 1000 °C. Results show that the Bru phase is not stable when Td ≤ 400 °C, while the structure of the HAp refines and transforms into Bru when Td ≥ 600 °C. Besides, the electrical resistance and capacitance of the pp‐HAp/Bru increase with Td, evidencing the progressive electrical depolarization of the material. Thermal depolarization also influences the specific orientation of the OH– ions, which is partially lost (≈50%). All such changes affect the catalytic efficiency of pp‐HAp/Bru, which is proven using a reaction that transforms CO2 gas into acetic acid and formic acid. Results show that the total reaction yield linearly decreases with increasing Td. Based on such observations, a simple process is designed that allows the reconstitution of the structure and restores the activity of such green catalysts.

Utilizing Edge-Oxidized Graphene Oxide to Enhance Cement Mortar's Properties Containing Crumb Rubber: Toward Achieving Sustainable Materials.

Scrap tires have become one of the most serious environmental issues worldwide in recent years. Exploiting this scrap has caught the attention of researchers in their efforts to conserve the environment. From a structural engineering materials perspective, a partial fine aggregate in cement mortar can be replaced by crumb rubber produced from scrap tires. This research mainly emphasizes the role of adding 0.1% edge-oxidized graphene oxide EOGO (by the weight of cement) in enhancing the properties of cement mortars containing 5%, 10%, and 15% of crumb rubber (by sand replacement). Cube and prism specimens were employed to investigate compressive and flexural strengths at 7- and 28-day curing ages. A porosity test was also conducted after 28 days of curing. In addition, a scanning electron microscopy (SEM) test was performed to investigate the effect of incorporating EOGO on the interfacial transition zone (ITZ). Results showed an enhancement of the mechanical properties of cement mortar, including compressive and flexural strengths, with the inclusion of EOGO in the mixes. The findings demonstrated that adding EOGO can improve the mechanical properties of mixes containing crumb rubber particles. Specifically, the mortar mix with 0.1% EOGO and 5% crumb rubber exhibited better performance compared with the virgin mix without rubber particles. Therefore, crumb rubber is viable for use as a sand replacement when EOGO is included.

Live-in or locked-out: housing of migrant workers before and during COVID-19

This article presents a comparative policy analysis of housing arrangements for migrant caregivers and farmworkers before and during COVID-19. By Juxtaposing structural conditions and industrial sectors, we explore the link between housing and labour migration regime, analysing its implications on migrant workers’ living conditions. Despite substantial differences in housing arrangements, prioritising employers’ needs and ethnonational values over migrant workers’ well-being and rights places migrant workers in both sectors at risk of exploitation. Crisis conditions, such as COVID-19, exacerbate the vulnerability of migrant workers to exploitation. By unpacking the repercussions of disparities between official rights-based housing policy and their implementation, this article seeks to contribute to the literature on the intersection between labour migration and housing policies. Rooted in a structural perspective on labour exploitation, we argue that bridging these disparities and preventing exploitation, while improving migrant workers’ living conditions, requires policymakers to address power imbalances between employers and migrant workers.

Voltage-Gated Ion Channels: Structure, Pharmacology and Photopharmacology.

Voltage-gated ion channels are transmembrane proteins responsible for the generation and propagation of action potentials in excitable cells. Over the last decade, advancements have enabled the elucidation of crystal structures of ion channels. This progress in structural understanding, particularly in identifying the binding sites of local anesthetics, opens avenues for the design of novel compounds capable of modulating ion conduction. However, many traditional drugs lack selectivity and come with adverse side effects. The emergence of photopharmacology has provided an orthogonal way of controlling the activity of compounds, enabling the regulation of ion conduction with light. In this review, we explore the central pore region of voltage-gated sodium and potassium channels, providing insights from both structural and pharmacological perspectives. We discuss the different binding modes of synthetic compounds that can physically occlude the pore and, therefore, block ion conduction. Moreover, we examine recent advances in the photopharmacology of voltage-gated ion channels, introducing molecular approaches aimed at controlling their activity by using photosensitive drugs.

Will the miniaturization of household size promote household carbon emissions in China? Analysis based on CFPS data

As the proportion of household carbon emissions to global carbon emissions continues to increase, reducing carbon emissions from household consumption has become an important way to achieve the goals of carbon peaking and carbon neutrality. How the trend of miniaturization of household size will affect household carbon emissions is a matter of concern. This paper uses a sample of 9,090 households from the China Family Panel Studies (CFPS) database in 2018 to empirically study the impact of changes in household size on household carbon emissions, from the perspective of household consumption structure and urban-rural areas. The research results indicate that the miniaturization of household size will increase household carbon emissions, the impact of household size on indirect HCEs is greater than on direct HCEs. The impact of household size on indirect HCEs is heterogeneous in consumption structure and the impact of household size on indirect HCEs from housing, transportation is greater than that of other consumption items. The impact of household size on urban household carbon emissions is greater than that in rural areas. The upgrading of household consumption structure and the miniaturization of household size promote the increase of HCEs jointly. Therefore, this paper proposes that under the trend of household miniaturization, energy-saving and emission reduction policies should focus on reducing indirect households carbon emissions, optimizing household structure and household consumption structure, enhancing environmental awareness among family members, establishing and improving the green consumption system, and building environment-friendly households.

The metaphysics of mechanisms: an ontic structural realist perspective

Existing metaphysical accounts of mechanisms commit to the existence of objects or entities posited in scientific theories, and thus fall within the category of maximal metaphysics. In this paper, I demonstrate the incompatibility of object-based metaphysics of mechanisms with the prevailing trend in the philosophy of physics by discussing the so-called bottoming-out problem. In response, I propose and flesh out a structuralist metaphysics of mechanisms based on Ontic Structural Realism (OSR), which is a kind of minimal metaphysics. I argue that the metaphysical underpinnings of mechanisms are structures, whose metaphysical nature is elaborated through comparison with existing metaphysical theories of mechanisms. After that, I address the concern of whether objects in mechanisms can be accommodated in my account by invoking existing metaphysical theories of objects in special science by structuralists, such as Ladyman, J., & Ross, D. (2007). Every Thing Must Go: Metaphysics Naturalized. Oxford University Press.)’s real pattern account, and suggesting a potential alignment between OSR and processual ontology. Finally, I demonstrate how my view can naturally serve as the metaphysics for Mechanism 2.0 and be applied to systems biology.

Heterogeneous‐Structured Refractory High‐Entropy Alloys: A Review of State‐of‐the‐Art Developments and Trends

AbstractRefractory high‐entropy alloys (RHEAs) inspire the development of novel high‐temperature structural materials due to their outstanding resistance to softening and phase stability at elevated temperatures. However, they struggle to simultaneously achieve high‐temperature strength and room‐temperature ductility, while exhibiting insufficient room‐temperature strain hardening capability. Heterogeneous structure strengthening possesses a unique plastic self‐coordinated ability, which can effectively maintain strain hardening rate to achieve an excellent combination of strength and ductility. Benefiting from slow atomic diffusion, severe lattice distortion, and broad compositional design space, RHEAs with heterogeneous structures can be prepared from both chemical composition and interface structure perspectives. Chemical composition heterogeneity primarily focuses on fluctuations of alloying elements at the nanoscale, along with the formation of heterogeneous precipitates and unique lamellar eutectic structures. While, interface structure heterogeneity manifests in the activation of phase transformation and twin boundaries within grains, along with the formation of grains of vastly different sizes. The trend in RHEAs development is toward structural‐functional integration. Heterogeneous structures can also optimize functional properties, such as irradiation resistance, biomedical properties, and high‐temperature softening resistance of RHEAs. Finally, a brief outlook is provided on the future development direction of heterogeneous structure RHEAs.

“Three-dimensional environment-friendly” amino acid functionalized chitosan: Uranium adsorption performance and mechanism research

To achieve the goals of “carbon peak and carbon neutrality” and sustainable development, we propose “Three-Dimensional Environment-Friendly” materials to balance the urgent need for the development of clean energy and the reduction of secondary environmental pollution during adsorbent preparation. In this study, three novel chitosan adsorbents (CMNSC-Leu, CMNSC-Pro, CMNSC-Phe) for uranium adsorption were designed on the basis of molecular level and successfully synthesized with three different amino acids (leucine, proline, phenylalanine) through amidation reaction in an aqueous environment using a sustainable green chitosan material. The uranium adsorption capacity of the three adsorbents was evaluated by batch adsorption, selectivity and recyclability studies. The adsorption reaction conformed to the pseudo-second-order model and was a spontaneous endothermic reaction. In particular, the maximum adsorption capacity of CMNSC-Pro for uranium was 462.7 mg·g−1 at C0 = 100 ppm. In addition, CMNSC-Pro showed better selectivity and good reusability. DFT calculation and IRI diagram were applied in this work to analyze the unique structure and adsorption process of CMNSC-Pro from the perspective of structure. Uranium was adsorbed by CMNSC-Pro via coordination, electrostatic interaction, and intraparticle diffusion. This work provided a new idea for the structural design and construction of new high-efficiency biomass adsorbents.

A hybrid evaluation of the intestinal absorption performance of compounds from molecular structure.

Intestinal absorption of compounds is significant in drug research and development. To evaluate this efficiently, a method combining mathematical modeling and molecular simulation was proposed, from the perspective of molecular structure. Based on the quantitative structure-property relationship study, the model between molecular structure and their apparent permeability coefficients was successfully constructed and verified, predicting intestinal absorption of drugs and interpreting decisive structural factors, such as AlogP98, Hydrogen bond donor and Ellipsoidal volume. The molecules with strong lipophilicity, less hydrogen bond donors and receptors, and small molecular volume are more easily absorbed. Then, the molecular dynamics simulation and molecular docking were utilized to study the mechanism of differences in intestinal absorption of drugs and investigate the role of molecular structure. Results indicated that molecules with strong lipophilicity and small volume interacted with the membrane at a lower energy and were easier to penetrate the membrane. Likewise, they had weaker interaction with P-glycoprotein and were easier to escape from it and harder to export from the body. More in, less out, is the main reason these molecules absorb well.