bluuebunny/crossref_metadata_2025 huggingface dataset:
Frontiers of Laser‐Based 3D Printing: A Perspective on Multi‐Photon Lithography
Authors: Zyla Gordon , Farsari Maria
Published: March 2024

Lasers are instrumental in enabling precise processing and fostering the development of new technologies. Particularly, ultrafast lasers, due to their unique interaction with matter, can achieve not only exceptional spatial precision but also meticulously determine the degree of modification. A prime example of this is laser‐based 3D printing through multi‐photon lithography (MPL). This approach remarkably enables the printing of true 3D structures at the micro‐ and nanoscale, without the need for masks or cumbersome tools, simply by using computer‐aided designs. Owing to these unique capabilities, MPL has emerged as a powerful manufacturing technique across various multidisciplinary fields. The ongoing growth in MPL's utilization has led to notable advancements in printing highly complex structures on different substrates, as well as improvements in resolution and throughput, and the development of novel photosensitive materials, which impressively facilitated MPL's expansion into broader fields over the last few years. In this perspective article, the aim is to highlight these advancements and recent trends in MPL. The current challenges of MPL will be explored, which need to be addressed to ensure its further integration into advanced Additive Manufacturing at the micro‐ and nanoscale. The future perspectives and opportunities of MPL as a laser‐based 3D printing approach will also be discussed.
Stress corrosion cracking susceptibility of a new nickel‐based alloy in different environments
Authors: Chen Zhenyu , Zhu Zhongliang , Khan Hasan I. , Chen Zhengzong , Zhang Naiqiang
Published: March 2024

Stress corrosion cracking (SCC) susceptibility of a new nickel‐based alloy C‐HRA‐2 under two types of superheated steam (SHS) (0.1 and 8 MPa) and supercritical water (SCW) (25 MPa) at 650°C was studied through slow strain rate tensile tests at a strain rate of 5 × 10−7 s−1. The results indicate that C‐HRA‐2 exhibits SCC susceptibility in both SHS and SCW, and the susceptibility increases with increasing pressure. Transgranular fracture (located inside) characterized by dimples/micropores and intergranular fracture (located at the edge) characterized by rock‐sugar‐like morphology was observed in all specimens. The brittleness of the alloy increases with the increase of medium pressure. A large number of cracks perpendicular to the loading axis were noticed on the gauge surface. The SCC mechanism of C‐HRA‐2 under steam and SCW is dynamic embrittlement.
Study of atmospheric corrosion of zinc in a tropical marine environment rich in H2S, resulting from the decomposition of Sargassum algae
Authors: Ahmed Mahado Said , Lebrini Mounim , Pellé Julien , Rioual Stephane , Amintas Olivia , Boulanger Carole , Lescop Benoit , Roos Christophe
Published: March 2024

The Martinique island, located in the Caribbean Sea, is subject to the stranding of Sargassum algae, which decompose and release toxic gases, such as hydrogen sulfide or ammonia. This study aims to investigate the atmospheric corrosion of zinc in these conditions. For this purpose, three sites in Martinique more or less impacted by Sargassum algae stranding were selected. Mass loss results after 1‐year exposure range from 1.9 µm for the site least impacted to 45.3 µm for the site most affected by Sargassum algae. This high value proves that the presence of Sargassum algae caused significant zinc degradation. The morphological structures and properties of the corrosion products obtained at the impacted and non‐impacted sites differ significantly. In the absence of Sargassum algae, “classical” corrosion products based on hydrozincite, simonkoleite, gordaite, and zinc hydroxylsulfate are observed. In the area close to the Sargassum seaweed stranding, the presence of elemental sulfur products, zinc hydroxylsulfate, and sphalerite is reported.
On a class of doubly nonlinear evolution equations in Musielak–Orlicz spaces
Authors: Akagi Goro , Schimperna Giulio
Published: March 2024

This paper is concerned with a parabolic evolution equation of the form , settled in a smooth bounded domain of , , and complemented with the initial conditions and with (for simplicity) homogeneous Dirichlet boundary conditions. Here, stands for a diffusion operator, possibly nonlinear, which may range in a very wide class, including the Laplacian, the ‐Laplacian for suitable , the “variable‐exponent” ‐Laplacian, or even some fractional order operators. The operator is assumed to be in the form with being measurable in and maximal monotone in . The main results are devoted to proving existence of weak solutions for a wide class of functions that extends the setting considered in previous results related to the variable exponent case where . To this end, a theory of subdifferential operators will be established in Musielak–Orlicz spaces satisfying structure conditions of the so‐called ‐type, and a framework for approximating maximal monotone operators acting in that class of spaces will also be developed. Such a theory is then applied to provide an existence result for a specific equation, but it may have an independent interest in itself. Finally, the existence result is illustrated by presenting a number of specific equations (and, correspondingly, of operators , ) to which the result can be applied.
The potential value of seasonal drought forecasts in the context of climate change: A case study of the African elephant conservation sector
Authors: Black Emily , Boult Victoria , Hirons Linda , Woolnough Steven
Published: March 2024

This study investigates meteorological drought in sub‐Saharan Africa within the context of elephant conservation. Prolonged drought significantly impacts elephants, leading to increased mortality rates and heightened human–elephant conflicts. We assess both the anticipated 21st century changes in impact‐relevant meteorological drought metrics and the efficacy of existing forecasting systems in predicting such droughts on seasonal time scales. The climate change element of our study uses the 6th Coupled Model Intercomparison Project (CMIP6) ensemble to evaluate projected change in 3‐month Standardized Precipitation Index (SPI3). We then carry out a quantitative assessment of seasonal forecast skill, utilizing 110 years of precipitation hindcasts generated by the European Centre for Medium Range Forecasting (ECMWF) system. Our findings indicate that persistent drought is projected to become more frequent over the 21st century in southern Africa, where the majority of elephants reside. Analysis of seasonal hindcasts indicates that, while the forecasts have greater skill than climatology, they remain highly uncertain. Previous work suggests that it may be possible to reduce this uncertainty by contextualizing forecasts within specific climate regimes. However, even with improved forecast skill, effective action hinges on the alignment of forecasts with the practical needs of conservation practitioners. Over the next decades, a co‐production approach will be critical for leveraging seasonal forecasts for climate change adaptation within the conservation sector.
Unconditional H2$$ {H}^2 $$‐stability of the Euler implicit/explicit SAV‐based scheme for the 2D Navier–Stokes equations with smooth or nonsmooth initial data
Authors: Chang Teng‐Yuan , Shiue Ming‐Cheng
Published: March 2024

In this article, we propose ‐unconditional stable schemes for solving time‐dependent incompressible Navier–Stokes equations with smooth or nonsmooth initial data, , . The ‐stability analysis is established by leveraging the scalar auxiliary variable (SAV) approach. When dealing with nonsmooth initial data, we utilize a limited number of iteration of the semi‐implicit scheme followed by the SAV scheme. The overall efficiency is greatly enhanced due to the minimal computational cost of the semi‐implicit scheme and the explicit treatment of the nonlinear term within the SAV approach. The proposed schemes investigate two types of scalar auxiliary variables: the energy‐based variable and the exponential‐based variable. Rigorous proofs of the ‐unconditional stability of both schemes have been provided. Notice that both proposed numerical schemes enjoy unconditional long time stability for smooth and nonsmooth initial data when . Numerical experiments have been conducted to demonstrate the theoretical results.
Processing water birds for food at the Island of Kökar in the Baltic Sea during the medieval and early modern period (ca. CE 1400–1700)
Authors: Kivikero Hanna , Eriksson Viktor
Published: March 2024

Few studies have been made of the specific importance of waterfowl as food in the Baltic Sea during the late medieval and early modern period. This study shows the seasonal importance of water birds to island and coastal inhabitants living in the middle of the Baltic Sea during the late medieval and early modern periods (ca. CE 1400–1700) and practical implementations for interpretation of cut and chop marks. The paper is based on a bird bone assemblage retrieved from a remote ecclesial site on the island group of Kökar, which is part of the Åland Islands, as well as historical documents and local specialist knowledge. The site was established by Franciscan friars somewhere in the mid‐15th century. Documents indicate that the friars had landownership, income from taxing nearby fisheries, and the right to seal tithe. These assets were taken over by the crown in the mid‐16th century due to the Reformation and a parish church was established on the same site after the friary was dissolved. The bone assemblages from the site include birds, mammals, and fish. The material shows a relatively small number of chicken bones in relation to waterfowl, allowing one to look closer into the structural food economy around water birds for the area. The bones also show several cut and chop marks, which have been analyzed to explore the possible processing of these birds. The results show that fowling was concentrated to a couple of species most likely during spring when these species were abundant. The placement of the cut and chop marks indicates that a large number of birds were likely processed at the same time.
Computational studies on exothermic carbon–carbon bond cleavages
Authors: Nicolaides Athanassios , Tomioka Hideo
Published: March 2024

Structural aspects of single CC bond dissociation energies are examined and it is shown that in certain cases a negative bond dissociation energy (BDE) implies a very weak bond and an unstable species prone to bond breaking resulting in dissociation or structural rearrangement. It is proposed that, in such cases, a better quantitative indicator for the strength of the bond is the activation energy required for its fission. o‐Phenelylene bis(nitrene) 1 is computed to have the most negative CC BDE for an observable species. Under cryogenic conditions, activation energy for the dissociation of this bond has been measured as only 2.8 kcal/mol, making it the weakest that we know of. An explanation based on the formation of two new bonds as responsible for this extremely weak bond is given.
Impact of open‐air processing on atmospheric pressure plasma deposition of poly(ethylene oxide) coatings for antifouling applications
Authors: Dekoster Tijs , Vos Rita , Jans Karolien , Van Roy Willem , Nisol Bernard , Duckert Bastien , Vanleenhove Anja , Delabie Annelies
Published: March 2024

Atmospheric pressure plasma deposition (APPD) of poly(ethylene oxide) (PEO)‐like antifouling coatings provides an attractive way to reduce biofouling for reliable biosensor operation. Cold atmospheric pressure plasma jets are designed to operate in open air. This paper demonstrates the impact of open‐air processing on the composition and properties of PEO‐like coatings by APPD with vinyl ether precursors. The open‐air environment inhibits polymerization as indicated by low deposition rates, oxygen incorporation in the coatings, and instability of the coatings in water. The composition and stability of the coatings improve by appropriate nozzle design and by deposition in an environment with lower air content. The resulting PEO‐like coatings are stable and antifouling for an antibody solution and inhibit adhesion of human fibroblast cells.
Conserved proline residues prevent dimerization and aggregation in the β‐lactamase BlaC
Authors: Chikunova A. , Manley M. P. , Heijjer C. N. , Drenth C. S. , Cramer‐Blok A. J. , Ahmad M. Ud Din , Perrakis A. , Ubbink M.
Published: March 2024

Evolution leads to conservation of amino acid residues in protein families. Conserved proline residues are usually considered to ensure the correct folding and to stabilize the three‐dimensional structure. Surprisingly, proline residues that are highly conserved in class A β‐lactamases were found to tolerate various substitutions without large losses in enzyme activity. We investigated the roles of three conserved prolines at positions 107, 226, and 258 in the β‐lactamase BlaC from Mycobacterium tuberculosis and found that mutations can lead to dimerization of the enzyme and an overall less stable protein that is prone to aggregate over time. For the variant Pro107Thr, the crystal structure shows dimer formation resembling domain swapping. It is concluded that the proline substitutions loosen the structure, enhancing multimerization. Even though the enzyme does not lose its properties without the conserved proline residues, the prolines ensure the long‐term structural integrity of the enzyme.
Integrating the analysis of human biopsies using post‐translational modifications proteomics
Authors: Bhardwaj Sonali , Bulluss Mitchell , D'Aubeterre Ana , Derakhshani Afshin , Penner Regan , Mahajan MaryAnn , Mahajan Vinit B. , Dufour Antoine
Published: March 2024

Proteome diversities and their biological functions are significantly amplified by post‐translational modifications (PTMs) of proteins. Shotgun proteomics, which does not typically survey PTMs, provides an incomplete picture of the complexity of human biopsies in health and disease. Recent advances in mass spectrometry‐based proteomic techniques that enrich and study PTMs are helping to uncover molecular detail from the cellular level to system‐wide functions, including how the microbiome impacts human diseases. Protein heterogeneity and disease complexity are challenging factors that make it difficult to characterize and treat disease. The search for clinical biomarkers to characterize disease mechanisms and complexity related to patient diagnoses and treatment has proven challenging. Knowledge of PTMs is fundamentally lacking. Characterization of complex human samples that clarify the role of PTMs and the microbiome in human diseases will result in new discoveries. This review highlights the key role of proteomic techniques used to characterize unknown biological functions of PTMs derived from complex human biopsies. Through the integration of diverse methods used to profile PTMs, this review explores the genetic regulation of proteoforms, cells of origin expressing specific proteins, and several bioactive PTMs and their subsequent analyses by liquid chromatography and tandem mass spectrometry.
Spontaneous Disentanglement and Thermalization
Authors: Buks Eyal
Published: March 2024

The problem of quantum measurement can be partially resolved by incorporating a process of spontaneous disentanglement into quantum dynamics. A modified master equation is proposed, which contains a nonlinear term giving rise to both spontaneous disentanglement and thermalization. It is found that the added nonlinear term enables limit cycle steady states, which are prohibited in standard quantum mechanics. This finding suggests that an experimental observation of such a limit cycle steady state can provide an important evidence supporting the spontaneous disentanglement hypothesis.
Design and multimodal locomotion plan of a hexapod robot with improved knee joints
Authors: Xu Kun , Qin Ripeng , Chen Cheng , Dong Guiyu , Chen Jiawei , Ding Xilun
Published: March 2024

Hexapod robots represent complex and highly redundant robotic systems capable of handling various tasks in extreme environments, such as planetary exploration and disaster response. To enhance the terrain adaptability and maneuverability of hexapod robots, we present a novel multimodal hexapod robot in this research. Our multimodal hexapod robot design incorporates knee joints with an improved multiparallel quadrilateral transmission mechanism, addressing singularity issues commonly encountered in legged robots. This enhancement not only improves the mechanical transmission characteristics of the knee joints but also increases the workspace of a single leg to achieve leg‐arm reuse functionality. In the presence of flat and structured terrain, the robot seamlessly switches to a wheeled locomotion mode, enabling swift traversal. Conversely, when faced with rough and unstructured terrain, it transitions into a legged mode, employing adaptive gait stability to navigate effectively. A novel operational mode in which the hexapod robot utilizes four legs for body support, while the remaining two legs are repurposed as arms is proposed. This innovative approach empowers the hexapod robot to perform dual‐arm manipulation without the need for additional degrees of freedom for the manipulator. To validate the effectiveness of our designed hexapod robot and multimodal motion planning algorithm, comprehensive experimental testing has been conducted, demonstrating the practicality and versatility of our system.
Toward Culturally Digitized Pedagogy: Informing Theory, Research, and Practice
Authors: McDaniel Dominique Skye
Published: March 2024

The article introduces and defines a theory of Culturally Digitized Pedagogy (CDP), an extension of asset pedagogies, namely culturally relevant and culturally sustaining pedagogies. The purpose of this framework is to add a critical lens for examining digital literacies and integrate culturally sustaining pedagogy principles with the reality of youth of Color's online lives. Research and practice need theories and pedagogies—such as youth digital literacies on social media—situating the conversation in new contexts and the possibilities these spaces cultivate for resisting monocultural and monolingual society by centering the asset‐orientation of youths' grassroots activism in online worlds. Thus, this paper introduces a conceptually grounded framework, culturally digitized pedagogy, which presents a pedagogical proposal aligned with contemporary educational practices and supported by current research. First, I describe the central argument of the article, forwarding a framework of culturally digitized pedagogy. Next, I frame culturally digitized pedagogy by discussing advancements it provides in current research. Then, I situate the unique activism of BIPOC youth. Last, I provide pedagogical interventions, grounded in the framework.
Investigation on Catalytic Cracking Performance of Metal Catalysts for 1,1,2‐TCE
Authors: Ge Xiang , Zhao Jigang , Yuan Xiangqian , Shen Haitao , Wu Shiyong
Published: March 2024

PVDC played an irreplaceable role in the field of sealed packaging, and its polymer monomer, VDC, was in short supply. At present, the saponification of 1,1,2‐TCE and sodium hydroxide was used to generate VDC in industry, which was a process with great environmental pollution. Catalytic dehydrochlorination of 1,1,2‐TCE to produce VDC was a green process route, but the selection of catalysts had always been controversial. This study aimed to screen catalysts suitable for industrial applications. The cesium based catalysts with good catalytic performance were systematically characterized and evaluated, and the overall reaction process was calculated using DFT calculation. The experimental results indicated that the cesium chloride catalyst with a 3 % molar fraction had the best catalytic performance, achieving 55.27 % conversion of 1,1,2‐TCE and 76.85 % selectivity for VDC, respectively. The reaction paths and transition state of several catalysts were calculated by DFT method. It was revealed that the activation energy required for the reaction of CsCl catalyst was the lowest, at 130.61 kcal/mol, and the energy of the product VDC was the lowest, at −63.25 kcal/mol, making it the most stable. The calculation results were consistent with the experimental data, indicating that cesium chloride catalyst had the best reaction performance. Therefore, the subsequent research could focus on the method of improving the supported dispersity of cesium chloride catalyst and the development of core‐shell catalyst to lay the foundation for further industrialization.
N‐Pyridylureas as Masked Isocyanates Fort the Late‐Stage Diversification of Pyridine‐N‐Oxides
Authors: Baykova Svetlana O. , Baykov Sergey V. , Geyl Kirill K. , Tolstoy Peter M. , Boyarskiy Vadim P.
Published: March 2024

A new method for the synthesis of pyridine‐ and quinoline‐N‐oxides containing a ureido or carbamoyl fragment in position 2 has been developed. This method concluded in the oxidation of relatively readily available substituted N,N‐dimethyl‐N′‐(pyridine‐2‐yl)ureas to the corresponding N‐oxides, followed by modification of the dimethylureide moiety. Being heated to 90 °C in the presence of amines in a solution of DMF or chlorobenzene, N‐oxide of N,N‐dimethyl‐N′‐(pyridine‐2‐yl)urea undergoes a transamination reaction without loss of the N‐oxide function. This produces N‐oxides of N‐alkyl/aryl‐N’‐(pyridine‐2‐yl)ureas in 24–99 % yields, (about 30 examples). Values of the NH protons chemical shifts are a good criterion for the selectivity of the reaction. The reaction is also applicable to N‐oxides of ureas substituted in the pyridine ring and to the quinoline congener. N‐Oxides of pyridine/quinoline‐containing carbamates can be similarly prepared by heating N‐oxides of N,N‐dimethyl‐N′‐(pyridine‐2‐yl)/(quinoline‐2‐yl)‐urea in an appropriate alcohol solution at 120 °C.
Structural Effects of 3D Inkjet‐Printed Ni(O)‐YSZ Pillared Electrodes on Performances of Solid Oxide Electrochemical Reactors
Authors: Jang Inyoung , Hankin Anna , Xie Zheng , Skinner Stephen J. , Kelsall Geoff H.
Published: March 2024

Increasing densities of reaction sites for gaseous reactants in solid oxide electrochemical reactors (SOERs), is a key strategy for achieving enhanced performance in either fuel cell or electrolysis modes. Fabrication of 3D structured components in SOERs can enhance those densities of reaction sites, which is achieved by 3D inkjet printing with high reproducibility, having developed inks with appropriate properties. First, the effects of pillar geometries on SOER performances are predicted through numerical simulations, enabling subsequent 3D printing to focus on the more effective geometries. Herein, the study reports the results of experimental validation of those predictions by evaluating the electrochemical performances of cells with various heights of 3D inkjet‐printed Ni(O)‐ yttria stabilized zirconia (YSZ) pillars and YSZ pillars. Those measurements prove that increasing pillar heights generally increases SOER peak power densities in fuel cell mode and increased current densities at the thermoneutral potential (1.285 V) in steam electrolysis mode, as predicted by simulations. With increasing pillar heights, more limitations in performance enhancement are found with YSZ electrolyte pillars than with Ni‐YSZ pillars, again as predicted by simulations. The subsequent microstructural analysis of Ni‐YSZ pillars proves the suitability of the Ni(O)‐YSZ composite particle ink formulation and the reliability of 3D printing.
FeP‐Based Nanotheranostic Platform for Enhanced Phototherapy/Ferroptosis/Chemodynamic Therapy
Authors: An Na , Tang Shuanglong , Wang Yuwei , Luan Jing , Shi Ying , Gao Minghui , Guo Chongshen
Published: March 2024

Ferroptosis is an iron‐dependent and lipid peroxides (LPO)‐overloaded programmed damage cell death, induced by glutathione (GSH) depletion and glutathione peroxide 4 (GPX4) inactivation. However, the inadequacy of endogenous iron and reactive oxygen species (ROS) restricts the efficacy of ferroptosis. To overcome this obstacle, a near‐infrared photo‐responsive FeP@PEG NPs is fabricated. Exogenous iron pool can enhance the effect of ferroptosis via the depletion of GSH and further regulate GPX4 inactivation. Generation of ·OH derived from the Fenton reaction is proved by increased accumulation of lipid peroxides. The heat generated by photothermal therapy and ROS generated by photodynamic therapy can enhance cell apoptosis under near‐infrared (NIR‐808 nm) irradiation, as evidenced by mitochondrial dysfunction and further accumulation of lipid peroxide content. FeP@PEG NPs can significantly inhibit the growth of several types of cancer cells in vitro and in vivo, which is validated by theoretical and experimental results. Meanwhile, FeP@PEG NPs show excellent T2‐weighted magnetic resonance imaging (MRI) property. In summary, the FeP‐based nanotheranostic platform for enhanced phototherapy/ferroptosis/chemodynamic therapy provides a reliable opportunity for clinical cancer theranostics.
Gradient Functional Layer Anode for Carbonate‐Superstructured Solid Fuel Cells with Ethane Fuel
Authors: Su Hanrui , Hu Yun Hang
Published: March 2024

Carbonate‐superstructured solid fuel cells (CSSFCs) are an emerging type of fuel cells with high flexibility of fuels. However, using ethane fuel for solid fuel cells is a great challenge due to serious degradation of their anodes. Herein, this critical issue is solved by creating a novel gradient functional layer anode for CSSFCs. First, a finer‐scale anode with a larger surface area is demonstrated to provide more active sites for the internal reforming reaction of ethane, achieving a 60% higher ethane conversion rate and 40% lower polarization resistance than conventional anodes. Second, incorporating a gradient functional layer into the anode results in an additional 50% enhancement in the peak power density of CSSFCs to a record high value (up to 241 mW cm–2) with dry ethane fuel at a low temperature of 550 °C, which is even comparable to the power density of conventional solid oxide fuel cells above 700 °C. Furthermore, the CSSFC with the gradient anode exhibits excellent durability for over 200 h. This finding provides a new strategy to develop efficient anodes for hydrocarbon fuels.
Super‐Flexible Water‐Proof Actuators
Authors: Liu Wei , Yang Xi , Yan Guilong , Wang Li , Lai Jingjuan , Li Zhenyu , Zhao Chunxia , Xiang Dong , Li Hui , Wu Yuanpeng
Published: March 2024

Humidity‐responsive materials hold broad application prospects in sensing, energy production, and other fields. Particularly, humidity‐sensitive, flexibility, and water resistance are pivotal factors in the development of optimized humidity‐responsive materials. In this study, hydrophobic linear polyurethane and hydrophilic 4‐vinylphenylboronic acid (4‐VPBA) form a semi‐intercross cross‐linking network. This copolymer of polyurethane exhibits excellent humidity‐sensitive, mechanical properties, and water resistance. Its maximum tensile strength and maximum elongation can reach 40.56 MPa and 543.47%, respectively. After being immersed in water at various temperatures for 15 days, it exhibited a swelling ratio of only 3.28% in water at 5 °C and 9.58% in water at 70 °C. While the presence of 4‐VPBA network imparts humidity‐sensitive, reversible, and multidirectional bending abilities, under the stimulus of water vapor, it can bend 43° within 1.4 s. The demonstrated material surpasses current bidirectional humidity actuators in actuating ability. Based on these characteristics, automatically opening waterproof umbrellas and windows, as well as bionic‐arms, crawling robots, and self‐propelled boats, are successfully developed.
Hierarchical Polyimide Microparticles with Controllable Morphology
Authors: Wang Zhichao , Hu Jianhua , Wang Haitao
Published: March 2024

Hierarchical polyimides (PIs) not only show outstanding thermal stability and high mechanical strength but also have great advantages in terms of microstructure and surface area, which makes them highly valuable in various fields such as aerospace, microelectronics, adsorption, catalysis, and energy storage. However, great challenges still remain in the synthesis of hierarchical PIs with well‐defined microstructure. Herein, polyamide acid salts (PAAS) with tunable ionization degree are synthesized first via the polymerization of dianhydride and diamine monomers in deionized water with 1,2‐dimethylimidazole (DMIZ). Then cationic cetyltrimethylammonium chloride (CTAC) is added to the PAAS aqueous solution to induce the formation of polyelectrolyte‐surfactant complexes based on electrostatic interaction. After a typical hydrothermal reaction (HTR) procedure, hierarchical PIs with different microstructures such as urchin‐like PI microparticles, flower‐like PI microparticles, and lamellar PI petals can be fabricated simply by changing the additive amount of DMIZ and CTAC. The nanostructure self‐assemblies of PAAS are dominated by the charges on macromolecular chains and the formation of hierarchical structures of polymers is ascribed to a geometrical selection process during crystal growth. This work provides valuable insights into the self‐assembly behaviors of polyelectrolyte systems for synthesizing well‐defined hierarchical polymers.
Spatially and Temporally Programmable Transparency Evolutions in Hydrogels Enabled by Metal Coordination toward Transient Anticounterfeiting
Authors: Zhao Jin , Zhou Yichen , Zhang Xing , Zheng Ying , Liu Junfeng , Bao Yongzhong , Shan Guorong , Guo Hui , Yu Chengtao , Pan Pengju
Published: March 2024

Hydrogels have emerged as promising candidates for anticounterfeiting materials, owing to their unique stimulus‐responsive capabilities. To improve the security of encrypted information, efforts are devoted to constructing transient anticounterfeiting hydrogels with a dynamic information display. However, current studies to design such hydrogel materials inevitably include sophisticated chemistry, complex preparation processes, and particular experimental setups. Herein, a facile strategy is proposed to realize the transient anticounterfeiting by constructing bivalent metal (M2+)‐coordination complexes in poly(acrylic acid) gels, where the cloud temperature (Tc) of the gels can be feasibly tuned by M2+ concentration. Therefore, the multi‐Tc parts in the gel can be locally programmed by leveraging the spatially selective diffusion of M2+ with different concentrations. With the increase of temperature or the addition of a complexing agent, the transparency of the multi‐Tc parts in the gel spontaneously evolves in natural light, enabling the transient information anticounterfeiting process. This work has provided a new strategy and mechanism to fabricate advanced anticounterfeiting hydrogel materials.
Numerical evaluation of the internal fracture mechanism of the single PBL shear connector considering the effects of position and strength of the transverse rebar
Authors: Karam Muhammad Shoaib , Nakamura Hikaru , Yamamoto Yoshihito , Tahir Muhammad , Hameed Rashid
Published: March 2024

The perfobond (PBL) shear connector reinforced with transverse rebar effectively contributes to sufficient ductility, bearing capacity, and anti‐fatigue behavior to hybrid structures. The construction practice involves the placement of the transverse rebar at the bottom position within the concrete dowel, whereas past studies employed transverse rebar in the center of the dowel; hence, there exists a gap between literature and design practices. Furthermore, there is no specific information in the design guidelines for hybrid structures on the influence of the position of the transverse rebar. Therefore, the current research deals with the analytical investigations employing the coupled Rigid Body Spring Model (RBSM) and the nonlinear solid Finite Element Method (FEM) that encompass the internal fracture behavior of concrete with the various parameters of transverse rebar, particularly the position and strength, to recognize the failure mechanism. It was determined that the numerical model accurately captured the test shear capacity and failure modes. The internal failure process of a specimen with transverse rebar at the bottom position, identical to actual field practice, revealed that as the height of the concrete region above the rebar rises, more compressive stresses in a trapezoidal manner are being generated, leading to an enhancement of the deformation capacity. Furthermore, it was confirmed that the specimen with the transverse rebar inserted at the bottom generates the greatest axial force, which is followed by the greatest shear capacity.
Openable Double‐Microtube Structure Driven by Pneumatic Balloon Actuator Arrays for Tubular Organ‐on‐a‐Chip
Authors: Shimizu Shiho , Nishizaki Keiichiro , Konishi Satoshi
Published: March 2024

Microfluidic platforms have revolutionized research in biomedical engineering, enabling efficient and controlled experimentation. Here, we present a novel microfluidic device, the double‐microtube, which offers parallel flow of different fluids. The device is fabricated by transforming a flat structure on a substrate using pneumatic balloon actuator arrays. The inner and outer tubes of the device can be independently controlled, allowing for individual opening and closing of each tubular structure. The inner and outer tubes have diameters of 1 mm and 3 mm, respectively. The device has been successfully tested for cell culture, showcasing its potential application for tubular organ‐on‐a‐chip studies, such as blood vessels and the small intestine. The presented double‐microtube structure promises a new level of control for microfluidic studies, offering exciting opportunities for researchers in the field of biomedical engineering. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.
Tax havens and transfer pricing strategies: Insights from emerging economies
Authors: Fonseca Peter Vaz da , Jucá Michele Nascimento , Vieito João Paulo da Torre
Published: March 2024

This study examines multinational companies in emerging markets, exploring their transfer pricing strategies for establishing tax havens. These companies employ various mechanisms (e.g., transfer pricing, profit transfers, and the reallocation of intangible assets) to minimize their tax liabilities. Today an increasing level of intangible assets facilitates smoother profit transfers to jurisdictions with lower tax burdens. Furthermore, these companies relocate their productive activities to tax havens, creating opportunities for corporate tax evasion and avoidance. Despite the efforts of governments and international organizations to propose the adoption of a minimum tax rate for different countries, these companies have been able to reduce or completely avoid paying taxes. Our study sample includes companies headquartered in emerging countries between 2010 and 2020. The study introduces some innovative elements, such as the variable “transfer pricing intensity,” which is derived from manual data collection. This variable enables analysis of the transfer pricing levels employed by multinational companies. In addition, a noteworthy contribution of this research is the use of an unconventional tax proxy known as AREA, which monitors the tax benefits associated with short‐ and long‐term debts. The results demonstrate that these companies employ a diverse range of instruments, often in combination, to reduce taxes in their conglomerates. These findings contribute significantly to a deeper understanding of the intricacies surrounding corporate tax optimization practices and provide valuable insights for governments in formulating robust policies that promote transparency and accountability in the international tax landscape.
Nitidine from Zanthoxylum rhetsa and its cytotoxic activities in vitro and in silico ADMET properties
Authors: Tuyen Tran Thi , Quan Pham Minh , Nghi Do Huu , Bach Pham Cao , Hiep Dang Hoang , Duong Nguyen Thanh , Linh Nguyen Nhat , Vien Trinh Anh , Minh Pham Thi Hong , Van Nguyen Thi Hong
Published: March 2024

Nitidine, a potential medicinal natural benzophenanthridine alkaloid, has expressed various bioactivities such as antibacterial, antifungal, antiviral, anti‐inflammatory, analgesic, and notably cytotoxicity. In this study, nitidine was isolated from trunk of Zanthoxylum rhetsa (Rutaceae) and its structure was elucidated by spectral data (1D and 2D NMR; and MS). The cytotoxicity of nitidine was assessed in vitro against five cancer cell lines, and normal cell line Vero. As the results, nitidine exhibited potent inhibitory activity against KB, LU‐1, HepG2, LNCaP and MCF7 cell lines with IC50 values of 0.28, 0.26, 0.27, 0.25 and 0.28 µm, respectively, while low‐cytotoxicity against normal cell line Vero with IC50 value of 140.65 µm. Comparing cytotoxic activity of nitidine with docking analysis in previous study, nitidine formed hydrogen bonds with residues Asn101 and Ala317 of tubulin and had a docking score of −14.45 kcal/mol, all the data proved nitidine would be a potential candidate for inhibiting the function of tubulin at the active site regarding binding affinity, dock pose, and ADMET‐where ADMET stands for absorption, distribution, metabolism, excretion and toxicity‐properties analysis.
Effect of alkali‐treated Putranjiva roxburghii seed shell filler on physico‐chemical, thermal, mechanical, and barrier properties of polyvinyl alcohol‐based biofilms
Authors: Krishnan Manthira Moorthy Muthukrishnan , Gurusamy Selvakumar , Pandiarajan Balasundar , Balasubramanian Balavairavan , Pandiarajan Narayanasamy , Suyambulingam Indran , Mavinkere Rangappa Sanjay , Siengchin Suchart
Published: March 2024

Biopolymers and bio‐fillers derived from natural, organic, and abundant resources have garnered more responsiveness owing to their affordability and degradability in the production of packaging plastics. This study explores the novel use of different proportions (5%, 10%, 15%, and 20%) of 5% alkali‐treated Putranjiva roxburghii seed shell filler (PRSSF) as a bio‐filler in combination with polyvinyl alcohol (PVA) for the first time. FTIR analysis showed the creation of robust hydrogen bonds and enhanced compatibility between the matrix and the alkalized PRSSF. The XRD results revealed that alkalized PRSSF strengthens the structural integrity of biofilms. The water absorption of the PVA/at PRSSF biofilm samples decreased by 88.38% at a higher composition (20%) of alkali‐treated PRSSF due to their alkalized hydrophobic filler. Due to the effect of at‐PRSSF into PVA, the resulting films demonstrated a degradation temperature and char residue of 334.8°C and 13.57%, respectively, and relatively better UV‐barrier properties in a range of visible light. When compared with pure PVA films, the tensile strength and corresponding modulus of PVA/20% at‐PRSSF films increased by 32.94% and 16.2%, respectively. Therefore, the PVA/at‐PRSSF biofilms produced in this study are ideal materials for wrapping and folding applications.

Highlights

PVA/at‐PRSSF films outperform in multiple aspects as compared with pure PVA.

Tensile strength of PVA/20%‐PRSSF films increased by 32.94%.

Elongation at break decreased with at‐PRSSF loading.

Water absorption in PVA/20% PRSSF biofilm decreased by 88.38%.

Fractography showed voids and agglomerations at high filler levels.
Wind turbine condition monitoring based on three fitted performance curves
Authors: Zhang Shuo , Robinson Emma , Basu Malabika
Published: March 2024

Based on SCADA data, this study aims at fitting three performance curves (PCs), power curve, pitch angle curve, and rotor speed curve, to accurately describe the normal behaviour of a wind turbine (WT) for performance monitoring and identification of anomalous signals. The fitting accuracy can be undesirably affected by erroneous SCADA data. Hence, outliers generated from raw SCADA data should be removed to mitigate the prediction inaccuracy, so various outlier detection (OD) approaches are compared in terms of area under the curve (AUC) and mean average precision (mAP). Among them, a novel unsupervised SVM‐KNN model, integrated by support vector machine (SVM) and k nearest neighbour (KNN), is the optimum detector for PC refinements. Based on the refined data by the SVM‐KNN detector, several common nonparametric regressors have largely improved their prediction accuracies on pitch angle and rotor speed curves from roughly 86% and 90.6%, respectively, (raw data) to both 99% (refined data). Noticeably, under the SVM‐KNN refinement, the errors have been reduced by roughly five times and 10 times for pitch angle and rotor speed predictions, respectively. Ultimately, bootstrapped prediction interval is applied to conduct the uncertainty analysis of the optimal predictive regression model, reinforcing the performance monitoring and anomaly detection.
Examining primary aromatic amines' stability in aqueous food simulants: effects of 3% acetic acid and water test conditions
Authors: Hoppe Maria , Gmeiner Margit , Schmid Petra
Published: March 2024

Primary aromatic amines (PAAs) may be found in food contact materials and can potentially migrate from packaging material into the packed foodstuffs. Certain members of this substance class are of particular concern due to their toxicological properties. Legislators and authorities require a risk assessment regarding the transfer of PAAs into food. The evaluation of PAAs’ migration into food relies on migration or extraction tests using aqueous and acidic food simulants or solvents. However, PAAs exhibit stability issues in acidic media, which could lead to an underestimation of migration. Therefore, a systematic stability study was conducted for 28 PAAs in 3% acetic acid and water at different storage conditions. Standard solutions of 2 and 10 ng/ml of the amines in these media were prepared and stored under the following conditions: 2 h at 40 °C, 70 °C, and 100 °C, and 10 days at − 20 °C, 4 °C, 20 °C, 40° C, and 60 °C. The test solutions were analyzed using liquid chromatography coupled to mass spectrometry, and recovery was calculated against freshly prepared standard solutions. It was found that several PAAs undergo a loss of recovery under the investigated conditions; 7 of the substances were identified to be the most unstable: 3,3ʹ-dimethoxybenzidine, 3,3ʹ-dimethylbenzidine, 6-methoxy-m-toluidine, 4-methoxy-m-phenylendiamine, 2,6-toluenediamine, benzidine and 2,4-toluenediamine. It was concluded that both time and storage temperature play a pivotal role in the stability of PAAs. The experiments also demonstrated that PAAs exhibit greater stability in water than in 3% acetic acid.
Ideals in the Convolution Algebra of Periodic Distributions
Authors: Sasane Amol
Published: March 2024

The ring of periodic distributions on $$\mathbb {R}^{\texttt {d}}$$

R

d

with usual addition of distributions, and with convolution is considered. Via Fourier series expansions, this ring is isomorphic to the ring $$\mathcal {S}'(\mathbb {Z}^{\texttt {d}})$$

S

′

(

Z

d

)

of all maps $$f:\mathbb {Z}^{\texttt {d}}\rightarrow \mathbb {C}$$

f
:

Z

d

→
C

of at most polynomial growth (that is, there exist a real number $$M>0$$

M
>
0

and an integer $$\texttt {m}\ge 0$$

m
≥
0

such that $$ |f(\varvec{n})|\le M(1+|\texttt{n}_1|+\cdots +|\texttt {n}_{\texttt {d}}|)^{\texttt {m}}$$

|
f

(

n

)

|

≤

M
(
1
+
|

n
1

|
+
⋯
+
|

n
d

|
)

m

for all $$\varvec{n}=(\texttt{n}_1,\cdots , \texttt {n}_{\texttt {d}})\in \mathbb {Z}^{\texttt {d}}$$

n

=

(

n
1

,
⋯
,

n
d

)

∈

Z

d

), with pointwise operations. It is shown that finitely generated ideals in $$\mathcal {S}'(\mathbb {Z}^{\texttt {d}})$$

S

′

(

Z

d

)

are principal, and ideal membership is characterised analytically. Calling an ideal in $$\mathcal {S}'(\mathbb {Z}^\texttt{d})$$

S

′

(

Z

d

)

fixed if there is a common index $$\varvec{n}\in \mathbb {Z}^{\texttt {d}}$$

n

∈

Z

d

where each member vanishes, the fixed maximal ideals are described, and it is shown that not all maximal ideals are fixed. It is shown that finitely generated (hence principal) prime ideals in $$\mathcal {S}'(\mathbb {Z}^{\texttt {d}})$$

S

′

(

Z

d

)

are fixed maximal ideals. The Krull dimension of $$\mathcal {S}'(\mathbb {Z}^{\texttt {d}})$$

S

′

(

Z

d

)

is proved to be infinite, while the weak Krull dimension is shown to be equal to 1.
OPTINOFA – Intelligenter Assistenzdienst zur strukturierten Ersteinschätzung in der Notaufnahme
Authors: Nyoungui Elisabeth , Karg Marina V. , Wieckenberg Marc , Esslinger Katrin , Schmucker Michael , Reiswich Andreas , Antweiler Kai L. , Friede Tim , Haag Martin , Dormann Harald , Blaschke Sabine
Published: March 2024

Hintergrund

Seit Beginn der letzten Dekade ist in Deutschland ein Anstieg der Fallzahlen in den Zentralen Notaufnahmen (ZNA) der Krankenhäuser zu verzeichnen, der zu rezidivierenden Overcrowding-Szenarien sowie zur Erhöhung der Risiken und Kosten der Notfallbehandlung führt. Dabei hat der Anteil ambulanter Notfallbehandlungen überproportional zugenommen. Im Rahmen des Innovationsfondsprojekts Optimierung der Notfallversorgung durch strukturierte Ersteinschätzung mittels intelligenter Assistenzdienste (OPTINOFA, Förderkennzeichen [FKZ] 01NVF17035) wurde hierzu ein intelligenter Assistenzdienst entwickelt.

Patient:innen und Methodik

Auf Basis etablierter Triagesysteme (Emergency Severity Index, ESI; Manchester Triage System, MTS) wurde für die 20 häufigsten Leitsymptome ein neuer Triagealgorithmus entwickelt und webbasiert auf mobilen Endgeräten zur Verfügung gestellt. Zur Bewertung der Validität, Reliabilität und Sicherheit des neuen Triageinstruments OPTINOFA wurde nach positivem Ethikvotum eine Pilotstudie in 3 ZNAs durchgeführt.

Ergebnisse

In die Pilotstudie wurden n = 718 Notfallpatienten (59 ± 22 Jahre; 349 männlich, 369 weiblich) eingeschlossen. In Bezug auf die Disposition (ambulant/stationär) ergab sich mit OPTINOFA eine Sensitivität von 91,1 % bei einer Spezifität von 40,7 % sowie eine gute Korrelation zur OPTINOFA-Triagestufe (Spearman’s Rank Correlation ρ = 0,41). In Bezug auf die Prädiktion der Disposition gemäß OPTINOFA-Triagestufe lag die „area under the curve“ (AUC) bei 0,73. Das intrahospitale Überleben von Patient:innen mit der OPTINOFA-Triage-Stufe 4 bzw. 5 lag bei 100 %. Die Assoziation zwischen der Verweildauer in der Notaufnahme und der OPTINOFA-Triage-Stufe war signifikant (p < 0,0001).

Schlussfolgerungen

Die Pilotstudie zeigt, dass OPTINOFA ein sicheres und valides Triagesystem zur transsektoralen Steuerung der Patientenströme in der Notaufnahme ist. Durch Festlegung von Behandlungsdringlichkeit und Versorgungssektor ergeben sich hiermit bedarfsgerechte Perspektiven zur Entlastung der ZNA durch engere Verzahnung zwischen den Sektoren der Notfallversorgung.
Molecular imprinted polymers: important advances in biochemistry, biomedical and biotechnology
Authors: Önal Acet Burcu , İnanan Tülden , Salieva Kalipa , Borkoev Bakyt , Odabaşı Mehmet , Acet Ömür
Published: March 2024

Molecularly imprinted polymers (MIPs) are handmade receptors that mimic the binding of natural antibodies. In other words, MIPs can selectively bind to the target molecule and qualify as bio-inspired synthetic materials. Today, MIPs are used extensively and are being developed further for biological applications. High cost and time consuming techniques are compelling factors for the field of biochemistry, biomedicine and biotechnology (3B), and there is an urgent need for an alternative, cheap, easy to produce, fast and effective method in these fields. MIPs stand out as a promising way for this purpose. MIPs have superiorities such as specific recognition specificity, excellent sensitivity selectivity and reusability. From this point of view, we examined MIP-related drug delivery studies, cell recognition, enzyme applications, in vivo applications, and applications for some important biomolecules. The aim of this review is to compile the utilizations, advantages, important developments and future expectations of MIPs for the fields of 3B.