bluuebunny/crossref_metadata_2025 huggingface dataset:
Sympathetic Innervation Regulates Osteocyte‐Mediated Cortical Bone Resorption during Lactation
Authors: Guo Qiaoyue , Chen Ningrong , Qian Cheng , Qi Cheng , Noller Kathleen , Wan Mei , Liu Xiaonan , Zhang Weixin , Cahan Patrick , Cao Xu
Published: April 2023

Bone undergoes constant remodeling by osteoclast bone resorption coupled with osteoblast bone formation at the bone surface. A third major cell type in the bone is osteocytes, which are embedded in the matrix, are well‐connected to the lacunar network, and are believed to act as mechanical sensors. Here, it is reported that sympathetic innervation directly regulates lacunar osteocyte‐mediated bone resorption inside cortical bone. It is found that sympathetic activity is elevated in different mouse models of bone loss, including lactation, ovariectomy, and glucocorticoid treatment. Further, during lactation elevated sympathetic outflow induces netrin‐1 expression by osteocytes to further promote sympathetic nerve sprouting in the cortical bone endosteum in a feed‐forward loop. Depletion of tyrosine hydroxylase‐positive (TH+) sympathetic nerves ameliorated osteocyte‐mediated perilacunar bone resorption in lactating mice. Moreover, norepinephrine activates β‐adrenergic receptor 2 (Adrb2) signaling to promote secretion of extracellular vesicles (EVs) containing bone‐degrading enzymes for perilacunar bone resorption and inhibit osteoblast differentiation. Importantly, osteocyte‐specific deletion of Adrb2 or treatment with a β‐blocker results in lower bone resorption in lactating mice. Together, these findings show that the sympathetic nervous system promotes osteocyte‐driven bone loss during lactation, likely as an adaptive response to the increased energy and mineral demands of the nursing mother.
Microwatt Volatile Optical Bistability via Nanomechanical Nonlinearity
Authors: Papas Dimitrios , Ou Jun‐Yu , Plum Eric , Zheludev Nikolay I.
Published: April 2023

Metastable optically controlled devices (optical flip‐flops) are needed in data storage, signal processing, and displays. Although nonvolatile memory relying on phase transitions in chalcogenide glasses has been widely used for optical data storage, beyond that, weak optical nonlinearities have hindered the development of low‐power bistable devices. This work reports a new type of volatile optical bistability in a hybrid nano‐optomechanical device, comprising a pair of anchored nanowires decorated with plasmonic metamolecules. The nonlinearity and bistability reside in the mechanical properties of the acoustically driven nanowires and are transduced to the optical response by reconfiguring the plasmonic metamolecules. The device can be switched between bistable optical states with microwatts of optical power and its volatile memory can be erased by removing the acoustic signal. The demonstration of hybrid nano‐optomechanical bistability opens new opportunities to develop low‐power optical bistable devices.
Composite Nanocoatings of Biomedical Magnesium Alloy Implants: Advantages, Mechanisms, and Design Strategies
Authors: Li Dan , Dai Danni , Xiong Gege , Lan Shuquan , Zhang Chao
Published: April 2023

The rapid degradation of magnesium (Mg) alloy implants erodes mechanical performance and interfacial bioactivity, thereby limiting their clinical utility. Surface modification is among the solutions to improve corrosion resistance and bioefficacy of Mg alloys. Novel composite coatings that incorporate nanostructures create new opportunities for their expanded use. Particle size dominance and impermeability may increase corrosion resistance and thereby prolong implant service time. Nanoparticles with specific biological effects may be released into the peri‐implant microenvironment during the degradation of coatings to promote healing. Composite nanocoatings provide nanoscale surfaces to promote cell adhesion and proliferation. Nanoparticles may activate cellular signaling pathways, while those with porous or core–shell structures may carry antibacterial or immunomodulatory drugs. Composite nanocoatings may promote vascular reendothelialization and osteogenesis, attenuate inflammation, and inhibit bacterial growth, thus increasing their applicability in complex clinical microenvironments such as those of atherosclerosis and open fractures. This review combines the physicochemical properties and biological efficiency of Mg‐based alloy biomedical implants to summarize the advantages of composite nanocoatings, analyzes their mechanisms of action, and proposes design and construction strategies, with the purpose of providing a reference for promoting the clinical application of Mg alloy implants and to further the design of nanocoatings.
Intermetallics Based on Sodium Chalcogenides Promote Stable Electrodeposition–Electrodissolution of Sodium Metal Anodes
Authors: Wang Yixian , Dong Hui , Katyal Naman , Vishnugopi Bairav S. , Singh Manish K. , Hao Hongchang , Liu Yijie , Liu Pengcheng , Mukherjee Partha P. , Henkelman Graeme , Watt John , Mitlin David
Published: April 2023

Sodiophilic micro‐composite films of sodium‐chalcogenide intermetallics (Na2Te and Na2S) and Cu particles are fabricated onto commercial copper foam current collectors (Na2Te@CF and Na2S@CF). For the first time a controllable capacity thermal infusion process is demonstrated. Enhanced wetting by the metal electrodeposition leads to state‐of‐the‐art electrochemical performance. For example, Na2Te@CF‐based half‐cells demonstrate stable cycling at 6 mA cm−2 and 6 mAh cm−2, corresponding to 54 µm of Na electrodeposited/electrodissolved by geometric area. Sodium metal batteries with Na3V2 (PO4)3 cathodes are stable at 30C (7 mA cm−2) and for 10 000 cycles at 5C and 10C. Cross‐sectional cryogenic focused ion beam (cryo‐FIB) microscopy details deposited and remnant dissolved microstructures. Sodium metal electrodeposition onto Na2Te@CF is dense, smooth, and free of dendrites or pores. On unmodified copper foam, sodium grows in a filament‐like manner, not requiring cycling to achieve this geometry. Substrate–metal interaction critically affects the metal–electrolyte interface, namely the thickness and morphology of the solid electrolyte interphase. Density functional theory and mesoscale simulations provide insight into support‐adatom energetics, nucleation response, and early‐stage morphological evolution. On Na2Te sodium atomic dispersion is thermodynamically more stable than isolated clusters, leading to conformal adatom coverage of the surface.
Understanding the CH activation of methane over single‐atom alloy catalysts by density functional theory calculations
Authors: Zhou Wenyu , Chen Yuping , Tan Luxi , Tang Qing , Lu Chenyang , Dong Lichun
Published: April 2023

As an important rate‐determining step in the oxidation of methane, the catalytic behaviors of single‐atom alloys (SAAs) on the CH activation reactions have not been fully understood. In this work, density functional theory calculations are performed to investigate the CH activation of methane on a series of SAAs with Cu(111/100) and Ag(111/100) as hosts. The reaction energies and the barriers for the CH dissociation reaction follow the traditional Brønsted–Evans–Polanyi (BEP) relationship, but the deviation from this linearity fitting is relatively large. To better describe the catalytic activity, a new nonlinear binary function is proposed to correlate the reaction barrier with the adsorption energies of *H and *CH3 products, which has higher correlation than the BEP relationship, and showed more accurate predictions of the CH activation reaction for unknown SAAs catalysis. Such mode might be able to extend to other catalyst systems to achieve large‐scale catalyst screening.
Interfacial Engineering of Magnesiophilic Coordination Layer Stabilizes Mg Metal Anode
Authors: Liu Yuan , Zhao Wanyu , Pan Zhenghui , Fan Zhengqing , Zhang Meng , Zhao Xiaoli , Chen Jianping , Yang Xiaowei
Published: April 2023

Rechargeable magnesium batteries (RMBs) are seriously plagued by the direct exposure of the Mg anode to the electrolyte components, leading to spontaneous and electrochemical side reactions and interfacial passivation. Herein, a benign coordination layer is constructed at the Mg/electrolyte interface where aniline with a strong magnesiophilic amine group and high stability to Mg is chosen as representative, which has higher adsorption energy than DME (1,2‐dimethoxyethane) and trace water. This Mg coordination environment mitigates side reactions, forming a non‐passivating interface consisting of aniline and much fewer by‐products after several cycles. Therefore, the Mg symmetrical cell operates with a low overpotential and uniform Mg0 deposition. This interfacial coordination can also be adopted for Mg anode protection in various electrolyte cases of Mg(TFSI)2 electrolyte systems.
Functional Nanopores Enabled with DNA
Authors: Xing Yongzheng , Rottensteiner Alexia , Ciccone Jonah , Howorka Stefan
Published: April 2023

Membrane‐spanning nanopores are used in label‐free single‐molecule sensing and next‐generation portable nucleic acid sequencing, and as powerful research tools in biology, biophysics, and synthetic biology. Naturally occurring protein and peptide pores, as well as synthetic inorganic nanopores, are used in these applications, with their limitations. The structural and functional repertoire of nanopores can be considerably expanded by functionalising existing pores with DNA strands and by creating an entirely new class of nanopores with DNA nanotechnology. This review outlines progress in this area of functional DNA nanopores and outlines developments to open up new applications.
Organocatalytic Atroposelective Cross‐Coupling of 1‐Azonaphthalenes and 2‐Naphthols
Authors: Da Bing‐Chao , Wang Yong‐Bin , Cheng Jun Kee , Xiang Shao‐Hua , Tan Bin
Published: April 2023

Atroposelective cross‐coupling is one of the most appealing routes to construct axially chiral binaphthyl molecules due to the modular and succinct nature. Although transition‐metal‐catalyzed cross‐couplings offer reliable synthetic means, alternative reaction modes that could be applied to broader substrate range without their pre‐functionalization is highly desirable. Herein we show that the application of chiral Brønsted acid catalyst as organocatalyst could accomplish cross‐coupling of 1‐azonaphthalenes and 2‐naphthols with high efficiency, exclusive C4‐selectivity as well as excellent enantioselectivity and functional group compatibility. The identification of acylimidazolinone auxiliary for azo activating group, effective remote catalyst control and arene resonance effect synergistically play key roles in the development of this method. The utility is further demonstrated by transformations of the products into other binaphthyl compounds with perfectly retained axial chirality.
Mechanistic Insight into Anion‐Binding Catalytic Living Cationic Polymerization
Authors: Li Maosheng , Li Hongyu , Zhang Xiaoyong , Wang Xianhong , Tao Youhua
Published: April 2023

Exploiting non‐covalent interactions to catalyze challenging ionic polymerizations is an ambitious goal but is in its infancy. We recently demonstrated non‐covalent anion‐binding catalysis as an effective methodology to enable living cationic polymerization (LCP) of vinyl ethers in an environmentally benign manner. Here, we further elucidate the structure‐reactivity relationships of the elaborately designed seleno‐cyclodiphosph(V)azanes catalysts and the roles of anion‐binding interactions by a combined theoretical DFT study and experimental study. The investigation suggests that the distinct cis‐cyclodiphosph(V)azane framework combined with “selenium effect” and electron‐withdrawing 3,5‐(CF3)2‐Phenyl substitution pattern in catalyst enables a critical contribution to accessing excellent stability, anion affinity and solubility under polymerization conditions. Thus, the catalyst could leverage anion‐binding interactions to precisely control reversible and transient dormant‐active species equilibrium, allowing it to dynamically bind, recognize and pre‐organize propagating ionic species and monomer, thereby facilitating efficient chain propagation and minimizing irreversible chain transfer events under mild conditions. The more in‐depth understanding of the mechanism for anion‐binding catalytic LCP reported herein should help to guide future catalyst design and to extend this concept to broader polymerization systems where ionic species serve as crucial intermediates.
Simultaneous Ring Contraction and Expansion Reaction: Electrosynthesis of Heterocycle‐Fused Fulleroids and Photovoltaic Application
Authors: Yin Zheng‐Chun , Li Mingjie , Niu Chuang , Wang Wei‐Feng , Liu Wen‐Rui , Zhang Qian‐Wen , Wang Guan‐Wu
Published: April 2023

Simultaneous electrochemical ring contraction and expansion reactions remain unexplored to date. Herein, the reductive electrosynthesis of heterocycle‐fused fulleroids from fullerotetrahydropyridazines and electrophiles in the presence of a trace amount of oxygen has been achieved with concurrent ring contraction and ring expansion. When trifluoroacetic acid and alkyl bromides are employed as electrophiles, heterocycle‐fused fulleroids with a 1,1,2,6‐configuration are regioselectively formed. In contrast, heterocycle‐fused fulleroids with a 1,1,4,6‐configuration are regioselectively produced as two separable stereoisomers if phthaloyl chloride is used as the electrophile. The reaction proceeds through multiple steps of electroreduction, heterocycle ring‐opening, oxygen oxidation, heterocycle contraction, fullerene cage expansion, and nucleophilic addition. The structures of these fulleroids have been determined by spectroscopic data and single‐crystal X‐ray diffraction analyses. The observed high regioselectivities have been rationalized by theoretical calculations. Representative fulleroids have been applied in organic solar cells as the third component and exhibit good performance.
Merging Styrene and Diene Structures to a Cyclic Diene: Anionic Polymerization of 1‐Vinylcyclohexene (VCH)
Authors: Hahn Christoph , Rauschenbach Moritz , Frey Holger
Published: April 2023

We report the first anionic polymerization of 1‐vinylcyclohexene (VCH). This structure may be considered as an intermediate between dienes and styrene. The polymerization of this cyclic 1,2‐disubstituted 1,3‐diene proceeded quantitatively in cyclohexane at 25 °C with sec‐butyllithium as an initiator. The obtained polymers have well‐controlled molecular weights in the range of 5 to 142 kg mol−1, controlled by the molar ratio of monomer and initiator, with narrow molecular weight distributions (Đ<1.07–1.20). In situ 1H NMR kinetic characterization revealed a weak gradient structure for the copolymers of styrene and VCH, (rSty=2.55, rVCH=0.39). P(VCH) obtained in cyclohexane with sec‐BuLi as an initiator showed both 1,4‐ and 3,4‐incorporation mode (ratio: 64 : 36). It was demonstrated that the microstructure of the resulting P(VCH) can be altered by the addition of a modifier (THF), resulting in increasing 3,4‐microstructure (up to 78 %) and elevated glass‐transition temperature up to 89 °C. Thus, the monomer VCH polymerizes carbanionically like a diene, however leading to rigid polymers with high glass transition temperature, which provides interesting options for combination with other dienes to well‐defined polymer architectures and materials.
DNA Nanotechnology for Investigating Mechanical Signaling in the Immune System
Authors: Hu Yuesong , Duan Yuxin , Salaita Khalid
Published: April 2023

Immune recognition occurs at specialized cell‐cell junctions when immune cells and target cells physically touch. In this junction, groups of receptor‐ligand complexes assemble and experience molecular forces that are ultimately generated by the cellular cytoskeleton. These forces are in the range of piconewton (pN) but play crucial roles in immune cell activation and subsequent effector responses. In this minireview, we will review the development of DNA based molecular tension sensors and their applications in mapping and quantifying mechanical forces experienced by immunoreceptors including T‐cell receptor (TCR), Lymphocyte function‐associated antigen (LFA‐1), and the B‐cell receptor (BCR) among others. In addition, we will highlight the use of DNA as a mechanical gate to manipulate mechanotransduction and decipher how mechanical forces regulate antigen discrimination and receptor signaling.
A General Preparation of Solid Solution‐Oxide Heterojunction Photocatalysts through Metal–Organic Framework Transformation Induced Pre‐nucleation
Authors: Wei Jiaxu , Mu Xijiao , Hu Yang , Liu Liangliang , Wu Xiaoxia , Liu Qingyi , Zhang Tong , Peng Yong , Cao Jing , Yan Chun‐Hua , Tang Yu
Published: April 2023

Solid solution‐oxide heterostructures combine the advantages of solid solution and heterojunction materials to improve electronic structure and optical properties by metal doping, and enhance charge separation and transfer in semiconductor photocatalysts by creating a built‐in electric field. Nevertheless, the effective design and synthesis of these materials remains a significant challenge. Here, we develop a generally applicable strategy that leverages the transformable properties of metal–organic frameworks (MOFs) to prepare solid solution‐oxide heterojunctions with controllable structural and chemical compositions. The process consists of three main steps. First, MOFs with different topological structures and metal centers are transformed, accompanied by pre‐nucleation of a metal oxide. Second, solid solution is prepared through calcination of the transformed MOFs. Finally, a heterojunction is formed by combining solid solution with another metal oxide group through endogenous overflow. DFT calculations and study on carrier dynamics show that the structure of the material effectively prevents electrons from returning to the bulk phase, exhibiting superior photocatalytic reduction performance of CO2. This study is expected to promote the controllable synthesis and research of MOF‐derived heterojunctions.
Site‐Selective C−H Functionalization of Carbazoles
Authors: Elsaid Mazen , Ge Robbie , Liu Chong , Maiti Debabrata , Ge Haibo
Published: April 2023

Carbazole alkaloids hold great potential in pharmaceutical and material sciences. However, the current approaches for C1 functionalization of carbazoles rely on the use of a pre‐installed directing group, severely limiting their applicability and hindering their overall efficiency. Herein, we report for the first time the development of direct Pd‐catalyzed C−H alkylation and acylation of carbazoles assisted by norbornene (NBE) as a transient directing mediator. Notably, the involvement of a six‐membered palladacycle intermediate was suggested in this case, representing the first example of such intermediacy within the extensively studied Pd/norbornene reactions realm.
Giant Molecule Acceptor Enables Highly Efficient Organic Solar Cells Processed Using Non‐halogenated Solvent
Authors: Zhuo Hongmei , Li Xiaojun , Zhang Jinyuan , Qin Shucheng , Guo Jing , Zhou Ruimin , Jiang Xin , Wu Xiangxi , Chen Zekun , Li Jing , Meng Lei , Li Yongfang
Published: April 2023

High efficiency organic solar cells (OSCs) based on A‐DA′D‐A type small molecule acceptors (SMAs) were mostly fabricated by toxic halogenated solvent processing, and power conversion efficiency (PCE) of the non‐halogenated solvent processed OSCs is mainly restricted by the excessive aggregation of the SMAs. To address this issue, we developed two vinyl π‐spacer linking‐site isomerized giant molecule acceptors (GMAs) with the π‐spacer linking on the inner carbon (EV‐i) or out carbon (EV‐o) of benzene end group of the SMA with longer alkyl side chains (ECOD) for the capability of non‐halogenated solvent‐processing. Interestingly, EV‐i possesses a twisted molecular structure but enhanced conjugation, while EV‐o shows a better planar molecular structure but weakened conjugation. The OSC with EV‐i as acceptor processed by the non‐halogenated solvent o‐xylene (o‐XY) demonstrated a higher PCE of 18.27 % than that of the devices based on the acceptor of ECOD (16.40 %) or EV‐o (2.50 %). 18.27 % is one of the highest PCEs among the OSCs fabricated from non‐halogenated solvents so far, benefitted from the suitable twisted structure, stronger absorbance and high charge carrier mobility of EV‐i. The results indicate that the GMAs with suitable linking site would be the excellent candidates for fabricating high performance OSCs processed by non‐halogenated solvents.
Chalcogen‐Bond‐Induced Double Helix Based on Self‐Assembly of a Small Planar Building Block
Authors: Mehrparvar Saber , Wölper Christoph , Haberhauer Gebhard
Published: April 2023

As a rule, helical structures at the molecular level are formed by non‐planar units. This makes the design of helices, starting from planar building blocks via self‐assembly, even more fascinating. Until now, however, this has only been achieved in rare cases, where hydrogen and halogen bonds were involved. Here, we show that the carbonyl‐tellurium interaction motif is suitable to assemble even small planar units into helical structures in solid phase. We found two different types of helices: both single and double helices, depending on the substitution pattern. In the double helix, the strands are connected by additional Te⋅⋅⋅Te chalcogen bonds. In the case of the single helix, a spontaneous enantiomeric resolution occurs in the crystal. This underlines the potential of the carbonyl‐tellurium chalcogen bond to generate complex three‐dimensional patterns.
A series of bifunctional metalloporphyrins as efficient catalysts for cycloaddition of CO2 with epoxides
Authors: Wang Dan , Gao Ziyuan , Duan Sujiao , Wei Jiaojiao , Ma Linjing , Wang Ning , Li Jun
Published: April 2023

Two porphyrins, named H2TEtImP and H2DEtImP, with the four and two N‐ethylated imidazole groups, respectively, as well as their metalloporphyrins, M‐TEtImP (M = Zn, Mn, Co, Mg) and Zn‐DEtImP, were synthesized and characterized by ultraviolet–visible (UV–Vis), mass spectrometry (MS), proton nuclear magnetic resonance (1H NMR), and Fourier transform infrared (FTIR) successfully. The catalytic activity of these newly synthesized porphyrins with metal centers and halogen ions as variables on the cycloaddition reaction between carbon dioxide (CO2) and epoxides was investigated under solvent‐free conditions. The experimental results strongly verified that both halogen ions and metal centers were indispensable active sites. The metal catalytic activity increased in the order Co < Mn < Mg < Zn. The turnover frequency (TOF) of Zn‐TEtImP for the cycloaddition reaction of CO2 and epichlorohydrin was as high as 2213 h−1 (120°C, 1 MPa CO2, 6 h). Moreover, the wide applicability of Zn‐TEtImP to this reaction was demonstrated by substrate extension experiments, and the excellent recyclability of Zn‐TEtImP was confirmed. Finally, the synergistic catalytic mechanism of Lewis acid (metal center) and nucleophile (Br−) was proposed based on the catalytic results.
Viscoelastic polyacrylate with hierarchical hollow zeolite for sound insulation
Authors: Li Yanxin , Ji Nana , Qu Huiqi , Lin Jingyi , Wang Dong , Meng Ruizhi , Li Bin , Wang Lei , Li Shaoxiang
Published: April 2023

Acoustic materials embed with inorganic fillers in viscoelastic polymers have promising applications in industrial settings. However, optimizing the sound insulation of composites by adjusting the microstructure of nanofillers remains a challenge. In this study, we synthesize adjustable hollow hierarchical Zeolite Socony Mobil #5 (ZSM‐5) which can be used as nanofillers in a sound insulation nanocomposite based on the polyacrylate (PA). The results show that the nanocomposites with 0.5 wt% hierarchical hollow ZSM‐5 can increase the sound transmission loss (STL) by 33.4%. The maximum STL value reaches as high as 40 dB. The damping properties of the nanocomposites were also improved by adding ZSM‐5 into the PA matrix. When the loading of hollow ZSM‐5 is 0.5 wt%, the storage modulus increased by 44%, as high as 4486.7 MPa. This strategy opens up a promising way for the sound insulation of composites based on controllable inorganic nanofillers.
Vine copula modeling dependence among cyber risks: A dangerous regulatory paradox
Authors: Carannante Maria , D'Amato Valeria , Fersini Paola , Forte Salvatore , Melisi Giuseppe
Published: April 2023

Dependence among different cyber risk classes is a fundamentally underexplored topic in the literature. However, disregarding the dependence structure in cyber risk management leads to inconsistent estimates of potential unintended losses. To bridge this gap, this article adopts a regulatory perspective to develop vine copulas to capture dependence. In quantifying the solvency capital requirement gradient for cyber risk measurement according to Solvency II, a dangerous paradox emerges: an insurance company does not tend to provide cyber risk hedging products as they are excessively expensive and would require huge premiums that it would not be possible to find policyholders.
Agreement of parent‐reported cognitive level with standardized measures among children with autism spectrum disorder
Authors: Lee Chimei M. , Green Snyder LeeAnne , Carpenter Laura A. , Harris Jill , Kanne Stephen , Taylor Cora M. , Sarver Dustin E. , Stephenson Kevin G. , Shulman Lisa H. , Wodka Ericka L. , Esler Amy ,   the SPARK Consortium
Published: April 2023

Assessing cognitive development is critical in clinical research of autism spectrum disorder (ASD). However, collecting cognitive data from clinically administered assessments can add a significant burden to clinical research in ASD due to the substantial cost and time required, and it is often prohibitive in large‐scale studies. There is a need for more efficient, but reliable, methods to estimate cognitive functioning for researchers, clinicians, and families. To examine the degree to which caregiver estimates of cognitive level agree with actual measured intelligence/developmental scores and understand factors that may impact that agreement, 1,555 autistic individuals (81.74% male; age 18 months–18 years) were selected from a large cohort (Simons Foundation Powering Autism Research for Knowledge, SPARK). Results suggest that querying parents about recent testing results and developmental diagnoses can provide valid and useful information on cognitive ability. The agreement of parental estimates varied with age, measured cognitive ability, autistic traits, and adaptive skills. In the context of large‐scale research efforts, parent‐reported cognitive impairment may be a good proxy for categorical IQ range for survey‐based studies when specific IQ scores are not available, circumventing the logistical and financial obstacles of obtaining neuropsychological or neurodevelopmental testing.
Use of ultrafiltration/diafiltration for the processing of antisense oligonucleotides
Authors: Gronke Robert S. , Ruanjaikaen Krisada , Delavari Armin , Immel‐Brown Jonas P. , Penrod Joseph C. , Lam Yik , Antia Firoz D.
Published: April 2023

Ultrafiltration/diafiltration (UF/DF) has been the hallmark for concentrating and buffer exchange of protein and peptide‐based therapeutics for years. Here we examine the capabilities and limitations of UF/DF membranes to process oligonucleotides using antisense oligonucleotides (ASOs) as a model. Using a 3 kDa UF/DF membrane, oligonucleotides as small as 6 kDa are shown to have low sieving coefficients (<0.008) and thus can be concentrated to high concentrations (≤200 mg/mL) with high yield (≥95%) and low viscosity (<15 centipoise), provided the oligonucleotide is designed not to undergo self‐hybridization. In general, the oligonucleotide should be at least twice the reported membrane molecular weight cutoff for robust retention. Regarding diafiltration, results show that a small amount of salt is necessary to maintain adequate flux at concentrations exceeding about 40 mg/mL. Removal of salts along with residual solvents and small molecule process‐related impurities can be robust provided they are not positively charged as the interaction with the oligonucleotide can prevent passage through the membrane, even for common divalent cations such as calcium or magnesium. Overall, UF/DF is a valuable tool to utilize in oligonucleotide processing, especially as a final drug substance formulation step that enables a liquid active pharmaceutical ingredient.
Black pleural effusion caused by a pancreaticopleural fistula secondary to chronic alcoholic pancreatitis exacerbation accompanying COVID‐19
Authors: Watanabe Yusuke , Takeda Yukihisa , Mizushima Reimi , Okuma Takashi , Toriyama Kazutoshi , Iwamoto Junichi , Nakamura Hiroyuki , Aoshiba Kazutetsu
Published: April 2023

Key Clinical Message

Pancreaticopleural fistula should be considered in alcohol abusers with pleural effusion, which can exhibit a black color.
Covalent Modification of Carbon Surfaces by Direct and Redox Catalysed Oxidation of Carboxylates in Acetonitrile – Concepts and Mechanisms
Authors: Morales‐Martínez Daniel , Ramírez‐Chan Daniel E. , Palacios‐Ramírez Jesús I. , Galicia Mónica , González Felipe J.
Published: April 2023

Electrografting is a relevant process that allows getting modified electrodes where organic molecules are covalently bonded to the electrode surface. The modification is typically performed using electrochemical reactions, where the transient passage by free radicals allows the formation of covalent bonds with the electrode surface. These intermediaries are generated over a wide potential window, and they are commonly prone to a second electron transfer (oxidation or reduction). Thus, this reaction competes with the surface reactions, slowing down the formation of films on the electrode. In the case of carboxylate oxidation, these competitive processes have been minimized by using a redox‐catalysed process which occurs at low oxidation potentials. The rate at which modifications procedures occur is relevant in the sense that they determine the properties of the polymeric films covalently attached to the electrode surfaces. Therefore, this review focuses on the main aspects of the direct and redox‐catalysed oxidation of carboxylates as a tool for the covalent modification of the surface of different carbon electrodes.
EVOLUTION OF USA COMPOSITE CODES: CHANGES IN CHAPTER I (COMPOSITE CONSTRUCTION) OF THE AISC 360‐22
Authors: Leon Roberto T.
Published: April 2023

This paper briefly reviews the evolution of composite codes in the USA in the context of important changes for the 2022 edition of the American steel design specification for buildings Major changes include the incorporation of composite walls as a new type of composite member, the addition of new provisions for shear capacity of filled members, and the introduction of a performance‐based procedure for qualifying new types of anchors. An appendix also allows for the use of high strength materials for concrete filled rectangular members. The paper then describes the write's opinion on (1) important issues that need to be addressed on the direction of future codes, (2) areas where more research work is needed to provide more consistent and simpler design rules and (3) the desirability of including additional topics into the main specification.
DEFORMATION CAPACITY AND DUCTILITY OF SHEAR CONNECTORS
Authors: Baertschi Roland , Garcia Samuel , Kroyer Robert , Sutter Pascal
Published: April 2023

Deformation capacity and slip range (eventually called “ductility”) of shear connectors are key parameters for the design of shear connectors in composite beams, especially in partial shear connection. Existing design rules require a deformation capacity of at least 6 mm for the use of shear connectors with plastic design methods. This rule is combined with the assumption of rigid‐ideal plastic behaviour of the shear connectors. Still, the real characteristics of most of today's usual shear connectors differ considerably from these assumptions, even more for shear connectors used in combination with metal decking. The paper describes the results of a literature research conducted in order to obtain reliable values for the deformation capacity and the slip range of headed stud shear connectors. Based on these results, advanced design methods can be used to realise composite beams with more realistic lower limits for the degree of partial shear connection and thus better economic performance.
PROGRESSIVE COLLAPSE MODELING OF A STEEL STRUCTURE WITH COMPOSITE SLAB USING COMMERCIAL FINITE ELEMENT SOFTWARE
Authors: Phillips Trent J. , Rassati Gian A. , Swanson James A. , Baldassino Nadia , Zandonini Riccardo
Published: April 2023

This paper presents a study on the modelling approaches for column loss scenarios using software that is widely available to structural engineers worldwide, with the goal of providing practical guidance to designers faced with the need or the opportunity to perform progressive collapse analyses. The presented study leverages recent experimental results on column removal in a composite frame obtained at the University of Trento. Comparisons between experimental data, results of high‐definition finite element analyses, and the simulation results obtained using commercially available software are performed and conclusions are drawn based on the modelling approach used. Furthermore, a parametric study on various column loss scenarios in a prototype building is conducted and the results are compared with highdefinition model results in literature. It is concluded that the proposed modelling approach can be successfully used in practical cases, with results that are quite satisfactory both at the local and at the global level.
NEW TYPE OF TRANSITION ZONE FOR STEEL‐CONCRETE HYBRID BEAMS IN BRIDGES
Authors: Kozioł P. , Lorenc W. , Kożuch M. , Kosecki W. , Stempniewicz A.
Published: April 2023

A new kind of composite connection is implemented in bridge engineering in Poland, which leads to a new type of steel‐concrete beams. First innovative bridges are constructed based on in‐depth scientific works. Perfobond shear connector (PBL) concept has been combined with standard geometries of composite dowels and in this way, efficient shear connection has been created that is used in combination with composite dowels. It enables a new type of beams that have more general forms than standard composite beams – they are named hybrid beams. There are intensive R&D works going on towards optimization of the transition zone concept. The article widens the already executed experimental tests, summarises the development of the hybrid beams, and presents the application of the hybrid beams in bridges.
ASSESSMENT OF GENERAL METHOD FOR COMPOSITE COLUMN DESIGN IN EN 1994‐1‐1 AND COMPARISON WITH SIMPLIFIED METHOD
Authors: Schäfer Markus , Zhang Qingjie , Zogu Pellumb , Bergmann Marco , Ergun Ozgun
Published: April 2023

Composite column design in accordance with EN 1994‐1‐1 can be computed by the general method or by simplified methods. For the general method, EN 1994‐1‐1 refers to a comprehensive FE‐Analysis. However, the recent Eurocode 4 does not provide sufficient guidance for the application of the general method and there is not a harmony in the literature on how to do it. Additional information may be found as non‐contradictory complementary information (NCI) in National Annexes (NA). This paper points out the procedure for the general method and refers to the changes and additional information provided by the draft of prEN 1994‐1‐1:2021. Furthermore, the modelling and computation by FE‐Analysis for several software applications are presented by implementing specified initial bow imperfections and predefined residual stresses for the steel section. The results obtained with the general method's approach are compared with that calculated by simplified method by the European buckling curves. In addition, the impact of different stress‐strain curves for concrete and strain limits introduced by Codes are investigated.
COMPARISON OF GEOMETRICAL IMPERFECTION DEFINITIONS ON ENCASED COMPOSITE COLUMNS
Authors: ERGUN Ozgun , SCHÄFER Markus
Published: April 2023

The imperfections stemming from manufacturing or construction practices have effects on capacities of structural columns. Bow imperfections or residual stresses are commonly investigated and well known examples of these imperfections. Since the composite construction generally has different stages than reinforced concrete or steel construction, there are other sources of imperfections for this field. Different approaches to consider geometrical imperfections are studied for this paper. These are namely the approach of EN‐1992‐1‐1 [1],EN 1994‐1‐1 [2] and EN 13670 [3]. Eurocode 2 and Eurocode 4 specify geometric imperfection for columns differently. Former introduces them as load eccentricity and latter introduces them as bow imperfections. EN 13670 giving the construction tolerances for reinforced concrete structures, has different methods to limit geometrical imperfections. For the purpose of comparing different approaches and their effect on capacity calculations, several composite columns were simulated using physical and geometrical non‐linear analysis, their load‐deflection relationships were monitored and capacities compared. An outlook of the ongoing investigation for the adaptation of geometrical imperfection for composite columns is further discussed.
STUDIES OF THE FATIGUE STRESS AND STRENGTH OF LARGE COMPOSITE BRIDGES WITH CANTILEVERS AND PRECAST CONCRETE ELEMENTS
Authors: Kraus Josef Karl , Geißler Karsten
Published: April 2023

When building large composite bridges with steel cantilevers as supports for partial‐depth precast deck‐elements, currently there are only recommendations available, which based on experiences with regard to the fatigue stressed connections of the cantilevers. In a research project currently being worked on for the Federal Ministry of Transport and Digital Infrastructure (BMVI) appropriate recommendations are developed based on experimental tests, accompanied by numerical analyses and structural monitoring. The article provides an insight into the ongoing research work at the Technical University of Berlin.
A NOVEL STRATEGY FOR SLIM‐FLOOR FIRE PROTECTION
Authors: Romero M.L. , Albero V. , Espinós A. , Serra E. , Hospitaler A. , Pons D.
Published: April 2023

This paper presents a novel slim‐floor configuration which consist of an I‐section steel profile welded to a wider bottom steel plate with an insulation layer of 5mm thick placed in between the two. The insulation layer is made up of a flexible and non‐combustible material, which protects the I‐section profile from the temperature rise through its bottom surface. Besides, this insulation layer remains protected from external agents with no need of maintenance because it is placed in the cavity created on purpose between the bottom plate and the lower flange of the steel profile thank to the weld between them. This new slim‐floor configuration is currently right‐protected by the Spanish Office of Patents and Trademarks with the reference number P201930438 and has been tested in the Universitat Politècnica de Valencia testing facilities to assess its thermal behaviour in fire. Specifically, the specimen was tested using an electric furnace where the slim‐floor is placed at the top surface. Therefore, the composite beam is exposed to the heat source only from the bottom surface, as it is the case in real fire scenarios. Moreover, the experimental campaign includes also a common slim‐floor specimen, without the insulation layer, in order to compare their thermal behaviour. The steel parts used in all the test specimens were grade S355, having a nominal yield strength of 355 MPa, the nominal compressive strength (cylindrical) of the cast in‐situ concrete was 30 MPa and the precast concrete hollow core slabs were manufactured with 45 MPa nominal compressive strength (cylindrical). In turn, the embedded reinforcing bars were grade S500, with 500 MPa nominal yield strength. The first experimental results have shown that the temperature gap between the bottom steel plate and the lower flange of the steel profile can reach up to 200°C. This impressive thermal gap delays the temperature rise along the I‐section steel profile which produces a significant improvement on the composite section fire resistant time, up to 90 or 120 minutes. Additionally, it should be highlighted that the observed improvement on the cross‐section thermal behaviour has been achieved using a novel configuration which no need maintenance in contrast with the common external protection systems using intumescent coating or other fireproofing materials.
EXPERIMENTAL AND NUMMERICAL INVESTIGATION OF THE FRICTION BASED DEMOUNTABLE SHEAR CONNECTOR
Authors: FODOR Jovan , SCHÄFER Markus
Published: April 2023

In order to provide sustainable structural solution for the steel‐concrete downstand composite beams in buildings by providing modularity and reusability, new demountable shear connector device based on frictional behaviour is devised. The mechanical behaviour of the newly developed connector is investigated both experimentally and numerically and its applicability in aforementioned application is assessed.
APPLICATION OF ROLLED SECTIONS IN COMPOSITE BRIDGES WITH SPAN OVER 50 METERS
Authors: Kożuch M. , Lorenc W. , Bartoszek B. , Stempniewicz A. , Windorpski H. , Struczyński M. , Sęk R. , Ochojski W.
Published: April 2023

Solutions using rolled sections instead of plated beams are strongly developed in Poland [1‐7]. One of the ideas is to use rolled sections HL1100 out of S460 steel for span region and variable height of girder at the piers (using different composite solutions) what has become a standard bridge type for continuous min. 3‐span bridges with internal spans range 50‐60 m. It took less than 10 years to come from the idea to standard market product. Appropriate R&D works have been carried out. The idea of using rolled section leaded to implementation of the double‐composite action and composite dowels and this way new structural forms of bridges appeared in Poland. The driving force for innovation in composite bridges in Poland is the design‐and‐build formula, international collaboration, open‐minded (not so conservative) young engineers and good economy for bridge market in Poland nowadays. In the paper applications of the considered solutions are presented.
NPS COMPOSITE BEAMS AND COLUMNS USED FOR THE ODENSE UNIVERSITY HOSPITAL
Authors: China Stefano , Tegon Aroldo
Published: April 2023

This document presents the case study of the Odense University Hospital, built with the NPS steel‐concrete composite frame. This is one of the most challenging projects currently in Europe: 250,000 square meters to be built in just over three years. The client has taken up the challenge of respecting timeframe and budget by focusing on offsite construction and digitalization of processes. Time constrains, safety and sustainability are the three main drivers of the project. Among these, the strict delivery time represents the main critical aspect. The expected turnkey delivery in 2022 assumed the choice of an extremely simple and fast construction method. Further advantages of using steel‐concrete composite structures with reference to the Odense University Hospital Case are explained.
CYCLIC BEHAVIOR OF COMPOSITE CONNECTIONS IN COMPOSITE FLOOR DIAPHRAGMS
Authors: Briggs Nicholas E. , Avellaneda‐Ramirez Raul E. , Coleman Kyle , Schafer Benjamin W. , Eatherton Matthew R. , Easterling W. Samuel , Hajjar Jerome F.
Published: April 2023

This research explores the cyclic behavior and strength of the composite concrete‐filled steel deck diaphragm system through experimental pushout and cantilever diaphragm tests. This work is part of the Steel Diaphragm Innovation Initiative (SDII), a multi‐institutional project that is investigating the behavior of composite steel deck diaphragms in steel buildings structures in high seismic zones. Sixteen unique pushout tests were conducted at Northeastern University as part of SDII. These specimens had variations in the orientation of the steel deck, concrete density, effective slab width, shear stud position and grouping. Additionally, seven of these tests were cyclic. Eight cantilever diaphragm tests were conducted at Virginia Tech as part of SDII. The parameters included deck height, slab thickness, concrete density, layout of shear studs, and reinforcement. These experimental tests provide valuable knowledge that aids in the characterization of the behavior and strength prediction of this structural system.
EVALUATION OF THE PLASTIC DEFORMATION CAPACITY OF COMPOSITE BEAMS THROUGH THE CONNECTION COEFFICIENT
Authors: Shimada Yuko
Published: April 2023

For safer structural design, a simple index that describes the plastic deformation capacity of composite beams is needed, similar to the connection coefficient in the case of strength. In this study, the relationships between the plastic deformation capacity and strength under varying material properties and geometric shapes of concrete and steel members were considered through finite element analyses. Based on the obtained results, the plastic deformation factor was defined as the ratio of two rotation angles. The minimum value of the connection coefficient in composite beams corresponding to the ductility factor under severe earthquakes was determined because the plastic deformation factor can be used similar to the ductility factor. In addition, the minimum value of the connection coefficient in bare steel beams that will be safe even if a concrete slab is added was determined; therefore, the design of bare steel beams and composite beams are connected by the connection coefficient.
SEISMIC PERFORMANCE OF PREFABRICATED CORE STEEL TUBE REINFORCED CONCRETE COLUMNS
Authors: Zhang Y.X. , Liu Y. , Ruan J. , Wang P.Z.
Published: April 2023

Prefabricated assembly accelerates the building construction process. A primary concern related to prefabricated assembly is the increased fragility of the connection between precast members compared to cast‐in‐situ members. On the other hand, core steel tube reinforced concrete (CSTRC) columns are increasingly being used in high‐rise structures to provide effective axial and lateral force resistance. This study proposes a prefabricated core steel tube reinforced concrete (PCSTRC) column which capitalizes on both the strength of the CSTRC column and the advantages of precast manufacturing, as shown in Fig. 1. The connection is designed to guarantee the integrity of the whole column. Two full‐scale PCSTRC columns with varying axial loads and two controlled specimens, namely a monolithic CSTRC column and a conventional reinforced concrete (RC) column, were fabricated and tested under quasi‐static cyclic loading in order to investigate their seismic performance. The test results demonstrate that all the columns experienced typical flexure‐controlled failure, while the PCSTRC columns suffered less visual damage than the monolithic controlled specimens. The PCSTRC column performed satisfactorily in terms of strength, stiffness, ductility, and general hysteretic behavior and had significantly greater load‐carrying and energy dissipation capacities than the conventional RC column. In addition, there were no apparent differences between the capacities of the CSTRC and PCSTRC columns. As axial load increased, the deformation capacity of the PCSTRC column decreased. Overall, the proposed prefabricated composite column demonstrates good seismic performance and can be considered for use in building construction.