Structural Diversity Research Articles

Supramolecular polyplexes from Janus peptide nucleic acids (bm-PNA-G5): self-assembled bm-PNA G-quadruplex and its tetraduplex with DNA.

Nucleic acids (DNA and RNA) can form diverse secondary structures ranging from hairpins to duplex, triplex, G4-tetraplex and C4-i-motifs. Many of the DNA analogues designed as antisense oligonucleotides (ASO) are also adept at embracing such folded structures, although to different extents with altered stabilities. One such analogue, peptide nucleic acid (PNA), which is uncharged and achiral, forms hybrids with complementary DNA/RNA with greater stability and specificity than DNA:DNA/RNA hybrids. Like DNAs, these single-stranded PNAs can form PNA:DNA/RNA duplexes, PNA:DNA:PNA triplexes, PNA-G4 tetraplexes and PNA-C4-i-motifs. We have recently designed Janus-like bimodal PNAs endowed with two different nucleobase sequences on either side of a single aminoethylglycyl (aeg) PNA backbone and shown that these can simultaneously bind to two complementary DNA sequences from both faces of PNA. This leads to the formation of supramolecular polyplexes such as double duplexes, triple duplexes and triplexes of double duplexes with appropriate complementary DNA/RNA. Herein, we demonstrate that Janus/bimodal PNA with a poly G-sequence on the triazole side of the PNA backbone and mixed bases on the t-amide side, templates the initial formation of a (PNA-G5)4 tetraplex (triazole side), followed by the formation of a PNA:DNA duplex (t-amide side). Such a polyplex shows synergistic overall stabilisation compared to the isolated duplexes/quadruplex. The assembly of polyplexes with a shared backbone for duplexes and tetraplexes is programmable and may have potential applications in the self-assembly of nucleic acid nano- and origami structures. It is also shown that Janus PNAs enter the cells better than the standard aeg-PNA oligomers, and hence have implications for in vivo applications as well.

When R&D investment improves firm value: the role of board gender diversity

Purpose Agency theory postulates that research and development (R&D) investments are subject to managerial discretion and thus may not enhance firm value as expected. The inconclusive empirical findings in the literature is a testament of that. This paper aims to investigate the interplay between board gender diversity (i.e. women on boards) and value relevance of firms’ effort to innovate as indicated by firms’ R&D investments. Design/methodology/approach Through a sample of 1,626 US-listed firms from the period 2004 to 2019, the authors examine whether board gender diversity promotes or hampers value relevance of firms’ efforts to innovate. The authors use ordinary least squares as the baseline model and address potential endogeneity through instrumental variable two-stage least square, and selection bias through Heckman selection model. Finally, the authors use the financial crisis of 2008 as a natural experiment to investigate the effect of board gender diversity during the crisis period. Findings The results show that board gender diversity positively moderates the relation between R&D and firm value. In times of financial crisis, R&D does not destroy firm value in firms with gender diverse board. The results are robust to measurement error, endogeneity issue, particularly simultaneity and selection bias. Practical implications The findings in this study have several practical implications. Firms that invest heavily in R&D should be mindful of gender diversity in their board recruitment strategies to enhance innovation outputs and firm value. Current and potential investors (i.e. shareholders) should take into consideration board gender diversity in their investment decision-making processes as the results show that gender diverse boards promote more effective governance, which, in turn, leads to better alignment of R&D investments with shareholder value. Regulators aiming to improve corporate governance policies should encourage gender diversity on the boards. The results align with global initiatives such as the United Nations Sustainable Development Goals, particularly Goal 5 on gender equality. Policymakers may use the findings in this study to advocate for more gender diverse governance structures within corporations. Originality/value This study investigates the role gender diverse boards play in creating value from firms’ R&D activities.

Novel tetrahydropyran-triazole hybrids with antiproliferative activity against human tumor cells.

A series of new hybrid compounds was prepared combining tetrahydropyran rings with different aromatic systems by means of a 1,2,3-triazole, using a building block strategy. The design of these structures was guided by Lead-Likeness and Molecular Analysis (LLAMA) software, adding modifications to our most potent scaffold (the tetrahydropyran ring) to generate promising "lead-like" candidates, which were subsequently compared against reported anticancer compounds. Our synthesized compounds demonstrated significant antiproliferative activity when compared with the standards cisplatin and 5-fluorouracil, across a panel of six different tumor cell lines. Moreover, compared with our group's previous hybrid compounds, these new structures exhibit similar activity while offering simpler synthesis and greater potential for structural diversification, a fact that was previously an issue. Further investigations on the most active compounds included assessments of reproductive cell survival, inhibition of cell migration, and effects on nuclear morphology, indicating potential diverse mechanisms of action for these compounds. Pharmacokinetic properties were also calculated for the whole series of compounds using the pkCSM online software.

Unlocking the Potential of Glutinol: Structural Diversification and Antifungal Activity against Phytopathogenic Fusarium Strains.

Unlike most common pentacyclic plant triterpenes, glutinol has a methyl group at position C-9 and a Δ5 double bond. At the same time, it lacks a methyl at C-10. These features significantly modify its chemical behavior compared to other triterpenes, particularly under oxidative conditions. Although the isolation of glutinol from various plant species has been documented, its chemistry remains largely unexplored. In this study, glutinol was isolated from the bark of Balfourodendron riedelianum as a starting material for top-down strategies of structural diversification, which included ring fusion, oxidation, aromatization, and ring cleavage reactions. Glutinol, together with a library of 22 derivatives, was evaluated for antifungal activity against three phytopathogenic Fusarium strains, F. solani, F. graminearum, and F. tucumaniae. Some of the derivatives displayed antifungal activity; in particular, compound 12, featuring a triazine ring, displayed the best fungicidal properties against F. solani and F. graminearum, while the ring B cleavage product 23 showed the best activity against F. tucumaniae. This study highlights the potential of glutinol as a scaffold for structural diversification, and these results may contribute to the design of novel fungicidal agents against phytopathogenic strains.

Virus-Based Separation of Rare Earth Elements.

The utilization of biomaterials for the separation of rare earth elements (REEs) has attracted considerable interest due to their inherent advantages, including diverse molecular structures for selective binding and the use of eco-friendly materials for sustainable systems. We present a pioneering methodology for developing a safe virus to selectively bind REEs and facilitate their release through pH modulation. We engineered the major coat protein of M13 bacteriophage (phage) to incorporate a lanthanide-binding peptide. The engineered lanthanide-binding phage (LBPh), presenting ∼3300 copies of the peptide, serves as an effective biological template for REE separation. Our findings demonstrate the LBPh's preferential binding for heavy REEs over light REEs. Moreover, the LBPh exhibits remarkable robustness with excellent recyclability and stability across multiple cycles of separations. This study underscores the potential of genetically integrating virus templates with selective binding motifs for REE separation, offering a promising avenue for environmentally friendly and energy-efficient separation processes.

A Green Approach to Oil Spill Mitigation: New Hybrid Materials for Wastewater Treatment

This study focuses on the development of adsorptive materials to retain degraded 5w40 motor oil. The materials were prepared using xanthan (XG) and XG esterified with acrylic acid (XGAC) as the polymeric matrix. LignoBoost lignin (LB), LB esterified with oleic (LBOL), stearic acid (LBST) and montmorillonite (CL) were added into XG and XGAC matrices to obtain the adsorbents. Adsorption experiments revealed that XG/CL/LBOL had the highest adsorption capacity at 46.80 g/g, followed by XGAC/CL at 45.73 g/g, and XG/CL at 37.58 g/g. The kinetic studies, employing the pseudo-second-order (PSO) model, indicated rapid sorption rates with a good correlation to experimental data. FTIR spectra analysis have evidenced the physical nature of adsorption process, involving interactions such as hydrogen bonding, van der Waals forces, and π–π interactions. Equilibrium data fitting to the Henry, Freundlich, and Temkin isotherm models showed that the adsorption occurs within materials diverse pore structures, enhancing oil retention. Structural parameters like density, porosity, and surface area were pivotal, with XG/CL/LBOL showing the most favorable properties for high oil adsorption. Additionally, it was found that the adsorption efficiency was influenced by the material’s morphology and the presence of chemical modifications. This comprehensive evaluation highlights the potential of these novel adsorptive materials for environmental remediation applications, offering an efficient and sustainable approach to reducing degraded motor oil pollution.

Advancements and challenges in plasmon-exciton quantum emitters based on colloidal quantum dots and perovskite nanocrystals

Abstract The Nobel Prizes in Physics (2022) and Chemistry (2023) heralded the recognition of quantum information science and the synthesis of quantum dots, respectively. This acknowledgment has propelled colloidal quantum dots and perovskite nanocrystals to the forefront of quantum technologies. Their distinct emission properties, facilitating the efficient generation of both single photons and photon pairs, render them particularly captivating. Moreover, their adaptability to diverse structures, ranging from traditional electronics to nanopatterned frameworks, underscores their pivotal role in shaping quantum technologies. Despite notable strides in synthesis, certain properties require refinement for enhanced applicability in quantum information, encompassing emission brightness, stability, single-photon indistinguishability, and entanglement fidelity of photon pairs. Here we offer an overview of recent achievements in plasmon-exciton quantum emitters based on luminescent semiconductor nanocrystals. Emphasizing the utilization of the light-matter coupling phenomenon, we explore how this interaction enables the manipulation of quantum properties without altering the chemical structure of the emitters. This approach addresses critical aspects for quantum information applications, offering precise control over emission rate, intensity, and energy. The development of these hybrid systems represents a significant stride forward, demonstrating their potential to overcome existing challenges and advance the integration of quantum emitters into cutting-edge quantum technology applications.

MolGC: molecular geometry comparator algorithm for bond length mean absolute error computation on molecules.

Density Functional Theory (DFT) is extensively used in theoretical and computational chemistry to study molecular and crystal properties across diverse fields, including quantum chemistry, materials physics, catalysis, biochemistry, and surface science. Despite advances in DFT hardware and software for optimized geometries, achieving consensus in molecular structure comparisons with experimental counterparts remains a challenge. This difficulty is exacerbated by the lack of automated bond length comparison tools, resulting in labor-intensive and error-prone manual processes. To address these challenges, we propose MolGC, a Molecular Geometry Comparator algorithm that automates the comparison of optimized geometries from different theoretical levels. MolGC calculates the mean absolute error (MAE) of bond lengths by integrating data from various DFT software. It provides interactive and customizable visualization of geometries, enabling users to explore different views for enhanced analysis. In addition, it saves MAE computations for further analysis and offers a comprehensive statistical summary of the results. MolGC effectively addresses complex graph labeling challenges, ensuring accurate identification and categorization of bonds in diverse chemical structures. It achieves a 98.91% average rate in correct bond label assignments on an antibiotics dataset, showcasing its effectiveness for comparing molecular bond lengths across geometries of varying complexity and size. The executable file and software resources for running MolGC can be downloaded from https://github.com/AbimaelGP/MolGC/tree/main .

Music Therapy with Preterm Infants and Their Families after Hospital Discharge: An Integrative Review

After discharge from a neonatal unit, families of preterm infants may require therapeutic support to address challenges related to their infant/s’ development, changed family circumstances, and/or parent wellbeing. This integrative review (IR) sought to examine the impact of music therapy on preterm infants and their families post-hospital discharge. A systematic search encompassing seven databases resulted in 83 citations, with six studies initially meeting the inclusion criteria. A further six studies were evaluated and selected upon their publication during the review process. Each study was assessed using the Mixed Methods Appraisal Tool (MMAT), followed by the identification of major themes and sub-themes. Our results suggest that music therapy contributed to creating supportive physical and metaphorical environments for preterm infants and their families, in which they could acquire essential skills, tools, and resources for fostering communication and connection with one another. Preterm infants and toddlers may have also enhanced their developmental skills through music therapy sessions post-discharge. Further investigation into the impact of music therapy on preterm infants and their caregivers at different timepoints after hospital discharge is recommended, as well as a comparison of individual and group music therapy outcomes on infant development and parent health. Future research should include a broader spectrum of family members, along with caregivers from diverse family structures and gender identities, reflecting practices already established in some clinical settings.

Unlocking the potential of cation vacancy-enriched ZnMn1.75O4 cathode for advanced aqueous aluminum-ion batteries

Manganese oxides are widely utilized in aqueous aluminum-ion batteries (AIBs) due to their high voltage and diverse crystal structures. However, the Jahn-Teller effect induced by Mn-O6 units results in irreversible structural damage. Here, we synthesized ZnMn1.75O4 (ZMO) cathodes loaded onto a carbon framework with manganese vacancies (VMn) for AIBs through ion substitution, manganese extraction, and carbonization on Mn-MIL. VMn stabilizes the ZMO structure by damping Mn-O bond vibrations and fosters Mn-O-C bonds between oxide particles and the carbon framework, effectively suppressing irreversible Mn2+ dissolution. Vacancy-modified cathodes provide more ion insertion sites, promoting ion diffusion. Ex-situ characterization revealed dominant H+ and Al3+ insertion behavior during different voltage regimes. Upon initial discharge, ion insertion into vacant lattice sites causes lattice distortions in adjacent unit cells, prompting ZMO to undergo a crystal structure transition and partial zinc deintercalation, resulting in a more stable cathode structure. Therefore, Al/ZMO batteries exhibit enhanced electrochemical performance.

Comparative study on mechanical properties and biomineralization of hooks in the diaspores of three epizoochorous plant species

Most of the plants using epizoochory show adaptations to this diaspore dispersal strategy by having the diaspores covered by barbs, hooks, spines or viscid outgrowths, which allow diaspores to easily attach to an animal surface. Many previous studies have been mainly focused on the dispersal distances and efficiency, or effectiveness of diverse attachment structures depending on their size, anatomy, and morphology. However, the knowledge about the mechanical properties of these structures remains rather poor. In this study, we use a combination of scanning electron microscopy, energy dispersive X-ray element analysis and nanoindentation, to examine the microstructure, biomineralization and mechanical properties of single hooks in Arctium minus, Cynoglossum officinale and Galium aparine. Both the biomineralization and mechanical properties of the hooks strongly differ in examined plant species; mechanical properties depend on the biomineralization pattern, such as the accumulation of silicon and calcium. Elastic modulus and hardness decrease in the series C. officinaleG. aparineA. minus. Anisotropic mechanical properties are found between the radial and longitudinal directions in each single hook. By characterizing the mechanical properties and biomineralization of plant hooks, this paper contributes to the understanding of attachment biomechanics related to seed dispersal. Statement of significanceThe dispersal of seeds is essential for plant survival. Many of the plants that use the outside surface of animals to transport the seeds show adaptations to this dispersal strategy by having the seeds covered with hooks. Although these hooks have various sizes, morphologies and anatomical structures, all of them provide mechanical interlocking to animal surfaces. To reduce the risk of interlocking failure, the hooks are usually reinforced by mineralization. However, the relationship between mineralization, mechanical properties and specialized function of plant hooks has been largely overlooked. Here we perform a characterization study on the hooks of three plant species. Our results deepen the current understanding of the mineralization-material-function relationship in specialized hooks of plant seeds.

Advancements in Coordination Chemistry and Trends in the Chemical Industry: Applications and Implications

Abstract: This research paper delves into the current advances in coordination chemistry alongside the evolving trends within the chemical industry, exploring their intersections and applications. Coordination chemistry has witnessed remarkable progress in recent years, driven by innovative synthetic methodologies and a deeper understanding of metal-ligand interactions. The study examines the synthesis and characterization of novel coordination complexes, highlighting their diverse structures and properties. Furthermore, it explores the role of coordination chemistry in various applications, ranging from catalysis and drug design to materials science and environmental remediation. Concurrently, the chemical industry is experiencing transformative shifts, embracing sustainable practices, and adapting to emerging regulatory frameworks. This paper investigates key trends shaping the chemical industry, such as green chemistry initiatives, circular economy principles, and the adoption of advanced manufacturing technologies. By synthesizing the latest research findings and industry developments, this study offers insights into the potential synergies between coordination chemistry advancements and the evolving landscape of the chemical industry, paving the way for innovative applications and sustainable solutions.

Morphoanatomy and evolution of the bracteole and sepal glands of the Amazonian genus Lophanthera A. Juss. (Galphimioid clade)

Abstract The presence of diverse secretory structures is emblematic of Malpighiaceae, such as the presence of nectaries secreting sugary nectar and elaiophores secreting oil-resin. Recent studies have demonstrated the morphoanatomical and chemical similarities between these two glands but, in general, there are no comparative morphoanatomical analysis on inflorescence glands. The Galphimioid clade is an excellent model for studies on the presence of secretory tissue due to the variation found among genera with regards to both their bracteole and sepal glands. In this work, we describe the morphoanatomy and histochemistry of bracteole and sepal glands in species of Lophanthera. Furthermore, we update the species geographic distribution map and explore the morphological diversity of both sepal and bracteole glands in the Neotropical Galphimioid clade. Samples collected in the field and obtained from herbarium specimens were processed under usual anatomical techniques. The bracteole glands varied in surface shape, while the calyx glands varied mainly in size. Anatomically, both types of gland have palisade secretory epidermis and vascularized secretory parenchyma. The presence of proteins, polysaccharides, phenolic compounds, and reducing sugar was detected by histochemical tests. The bracteole glands of the inflorescences in Lophanthera were characterized as nectaries that produce a hydrophilic secretion. The sepal glands were identified as elaiophores by the presence of lipids and fixed oil. The results reinforce the functional role of floral nectaries of bracteoles and elaiophores of sepals according to the nature of the secretion, its potential visitors, and reported literature. The morphofunctional diversity reported in this work is unprecedented for the clade and is fundamental in the adaptive evolution of the family.

Engineering the Electrostatic Interactions between Oppositely Charged Polymer-Grafted Nanoparticles for Constructing Colloid Molecules on Substrates.

Arrays of nanoparticle (NP) clusters with controlled architectures show broad applications in nanolasers, sensors, and photocatalysis, but the fabrication of these arrays on substrates remains a grand challenge. This review presents a highly effective polymer-based strategy for the process-directed self-assembly of binary polyelectrolyte-grafted NPs (PGNPs) bearing opposite charges into stable colloidal molecules (CMs) on substrates via electrostatic interactions. The coordination number (x) of ABx CMs can be tuned by adjusting the pH or ionic strength of the solution or by employing different combinations of PGNPs with varying charge densities. Large-area CMs with diverse structures ranging from AB to AB7 can be constructed on substrates in high yields. This approach is applicable to PGNPs with different cores of NPs. This assembly strategy offers a useful tool for the fabrication of structurally precise assemblies on substrates with broad applications.

The cytoskeleton controls the dynamics of plasma membrane proteins and facilitates their endocytosis in plants.

Plasma membranes (PMs) are highly dynamic structures where lipids and proteins can theoretically diffuse freely. However, reports indicate that PM proteins do not freely diffuse within their planes but are constrained by cytoskeleton networks, though the mechanisms for how the cytoskeleton restricts lateral diffusion of plant PM proteins are unclear. Through single-molecule tracking, we investigated the dynamics of six Arabidopsis (Arabidopsis thaliana) PM proteins with diverse structures and found distinctions in sizes and dynamics among these proteins. Moreover, we showed that the cytoskeleton, particularly microtubules, limits the diffusion of PM proteins, including transmembrane and membrane-anchoring proteins. Interestingly, the microfilament skeleton regulates intracellular transport of endocytic cargo. Therefore, these findings indicate that the cytoskeleton controls signal transduction by limiting diffusion of PM proteins in specific membrane compartments and participating in transport of internalized cargo vesicles, thus actively regulating plant signal transduction.

Enhancers associated with unstable RNAs are rare in plants.

Unstable transcripts have emerged as markers of active enhancers in vertebrates and shown to be involved in many cellular processes and medical disorders. However, their prevalence and role in plants is largely unexplored. Here, we comprehensively captured all actively initiating (nascent) transcripts across diverse crops and other plants using capped small (cs)RNA sequencing. We discovered that unstable transcripts are rare in plants, unlike in vertebrates, and when present, often originate from promoters. In addition, many 'distal' elements in plants initiate tissue-specific stable transcripts and are likely bona fide promoters of as-yet-unannotated genes or non-coding RNAs, cautioning against using reference genome annotations to infer putative enhancer sites. To investigate enhancer function, we integrated data from self-transcribing active regulatory region (STARR) sequencing. We found that annotated promoters and other regions that initiate stable transcripts, but not those marked by unstable or bidirectional unstable transcripts, showed stronger enhancer activity in this assay. Our findings underscore the blurred line between promoters and enhancers and suggest that cis-regulatory elements can encompass diverse structures and mechanisms in eukaryotes, including humans.

Self-Assembled Monolayer Transporters Enable Reagentless Analysis of Small Molecule Analytes.

The detection of small molecules beyond glucose remains an ongoing challenge in the field of biomolecular sensing owing to their small size, diverse structures, and lack of alternative non-enzymatic sensing methods. Here, we present a new reagentless electrochemical approach for small molecule detection that involves directed movement of electroactive analytes through a self-assembled monolayer to an electrode surface. Using this method, we demonstrate detection of several physiologically relevant small molecules as well as the capacity for the system to operate in several biological fluids. We anticipate that this mechanism will further improve our capacity for small molecule measurement and provide a new generalizable monolayer-based technique for electrochemical assessment of various electroactive analytes.

An agent-based model of cross-platform information diffusion and moderation

Social media platforms are highly interconnected because many users maintain a presence across multiple platforms. Consequently, efforts to limit the spread of misinformation taken by individual platforms can have complex consequences on misinformation diffusion across the social media ecosystem. This is further complicated by the diverse social structures, platform standards, and moderation mechanisms provided on each platform. We study this issue by extending our previous model of Reddit interactions and community-specific moderation measures. By adding a followership-based model of Twitter interactions and facilitating cross-platform user participation, we simulate information diffusion across heterogeneous social media platforms. While incorporating platform-specific moderation mechanisms, we simulate interactions at the user level and specify user-specific attributes. This allows practitioners to conduct experiments with various types of actors and different combinations of moderation. We show how the model can simulate the impacts of such features on discussions facilitated by Reddit and Twitter and the cross-platform spread of misinformation. To validate this model, we use a combination of empirical datasets from three U.S. political events and prior findings from user surveys and studies.

The cyanobacterial protein VIPP1 forms ESCRT-III-like structures on lipid bilayers.

The biogenesis and maintenance of thylakoid membranes require vesicle-inducing protein in plastids 1 (VIPP1). VIPP1 is a member of the endosomal sorting complex required for transport-III (ESCRT-III) superfamily, whose members form diverse filament-based supramolecular structures that facilitate membrane deformation and fission. VIPP1 cryo-electron microscopy (EM) structures in solution revealed helical rods and baskets of stacked rings, with amphipathic membrane-binding domains in the lumen. However, how VIPP1 interacts with membranes remains largely unknown. Here, using high-speed atomic force microscopy (HS-AFM), we show that VIPP1 assembles into right-handed chiral spirals and regular polygons on supported lipid bilayers via ESCRT-III-like filament assembly and dynamics. VIPP1 filaments grow clockwise into spirals through polymerization at a ring-shaped central polymerization hub, and into polygons through clockwise polymerization at the sector peripheries. Interestingly, VIPP1 initially forms Archimedean spirals, which upon maturation transform into logarithmic spirals through lateral annealing of strands to the outermore low-curvature spiral turns.

Generalized [formula omitted]-fold Darboux transformation and localized waves for an integrable reduced spin Hirota-Maxwell-Bloch system in an erbium doped fiber

In this paper, under investigation is an integrable reduced spin Hirota-Maxwell-Bloch (rsHMB) system, which describes the transmission of the femtosecond pulses in an erbium doped fiber. Based on the existing N-fold Darboux transformation, we establish a generalized (n,N−n)-fold Darboux transformation for the rsHMB system, where n and N are the positive integers (n≤N). The Nth-order degenerate soliton and Nth-order rogue-wave solutions for the rsHMB system are obtained via the generalized (1,N−1)-fold Darboux transformation. By means of the generalized (2,N−2)-fold Darboux transformation, we derive the Nth-order hybrid wave solutions describing the interaction between the (N−1)th-order rogue wave and the first-order breather. The above solutions are discussed graphically, which exhibit the diverse wave structures including the triangle and pentagon, among others.