bluuebunny/crossref_metadata_2025 huggingface dataset:
SARS-CoV-2 S protein disrupts the formation of ISGF3 complex through conserved S2 subunit to antagonize type I interferon response
Authors: Cai Zeng , Ni Wenjia , Li Wenkang , Wu Zhixuan , Yao Xiaoqian , Zheng Yucheng , Zhao Yongliang , Yuan Weifeng , Liang Simeng , Wang Qi , Tang Mingliang , Chen Yu , Lan Ke , Zhou Li , Xu Ke
Published: December 2024

Viral immunosuppression substantially affects the host immune response of infected patients and the protective efficacy of vaccines. Here, we found that the spike (S) protein, the major vaccine antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), strongly suppresses host innate immunity by inhibiting interferon-stimulated gene (ISG) expression through both S1 and S2 subunits. Mechanistically, the S protein inhibited the formation of the classic interferon-stimulated gene factor 3 (ISGF3) complex composed of STAT1, STAT2, and IRF9 by competing with STAT2 for binding to IRF9, thereby impeding the transcription of ISGs. A strong interaction between S and the STAT1/STAT2 proteins further traps the ISGF3 complex in the endoplasmic reticulum and hinders the nuclear translocation of ISGF3. Notably, the interferon-inhibitory mechanism of the S protein was universal among SARS-CoV-2 variants and other human coronaviruses, including SARS-CoV, Middle East respiratory syndrome coronavirus (MERS-CoV), human coronavirus 229E (HCoV-229E), human coronavirus NL63 (HCoV-NL63), and human coronavirus HKU1 (HCoV-HKU1), through the most evolutionarily conserved region of S2 subunit. Taken together, the findings of this study reveal a new mechanism by which the coronavirus S protein attenuates the host antiviral immune response and provides new insights into the proper design of coronavirus S-based vaccines to prevent immunosuppressive effects.

IMPORTANCE

This study unveils a new mechanism by which the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein attenuates the host’s antiviral immune response. The interferon-inhibitory mechanism of the S protein was universal among SARS-CoV-2 variants and other human coronaviruses, including SARS-CoV, MERS-CoV, HCoV-229E, HCoV-NL63, and HCoV-HKU1, through conserved S2 domains. Our study expands the understanding of SARS-CoV-2 and other human coronaviruses in evading antiviral immune strategies, which is very important for the design and optimization of vaccine antigens, thus providing a theoretical basis for human anti-coronavirus immunity and understanding the interaction between the host and coronavirus.
Identification of novel fructo-oligosaccharide bacterial consumers by pulse metatranscriptomics in a human stool sample
Authors: Prattico Catherine , Gonzalez Emmanuel , Dridi Lharbi , Jazestani Shiva , Low Kristin E. , Abbott D. Wade , Maurice Corinne F. , Castagner Bastien
Published: December 2024

Dietary fibers influence the composition of the human gut microbiota and directly contribute to its downstream effects on host health. As more research supports the use of glycans as prebiotics for therapeutic applications, the need to identify the gut bacteria that metabolize glycans of interest increases. Fructo-oligosaccharide (FOS) is a common diet-derived glycan that is fermented by the gut microbiota and has been used as a prebiotic. Despite being well studied, we do not yet have a complete picture of all FOS-consuming gut bacterial taxa. To identify new bacterial consumers, we used a short exposure of microbial communities in a stool sample to FOS or galactomannan as the sole carbon source to induce glycan metabolism genes. We then performed metatranscriptomics, paired with whole metagenomic sequencing, and 16S amplicon sequencing. The short incubation was sufficient to cause induction of genes involved in carbohydrate metabolism, like carbohydrate-active enzymes (CAZymes), including glycoside hydrolase family 32 genes, which hydrolyze fructan polysaccharides like FOS and inulin. Interestingly, FOS metabolism transcripts were notably overexpressed in
Blautia
species not previously reported to be fructan consumers. We therefore validated the ability of different
Blautia
species to ferment fructans by monitoring their growth and fermentation in defined media. This pulse metatranscriptomics approach is a useful method to find novel consumers of prebiotics and increase our understanding of prebiotic metabolism by CAZymes in the gut microbiota.

IMPORTANCE

Complex carbohydrates are key contributors to the composition of the human gut microbiota and play an essential role in the microbiota’s effects on host health. Understanding which bacteria consume complex carbohydrates, or glycans, provides a mechanistic link between dietary prebiotics and their beneficial health effects, an essential step for their therapeutic application. Here, we used a pulse metatranscriptomics pipeline to identify bacterial consumers based on glycan metabolism induction in a human stool sample. We identified novel consumers of fructo-oligosaccharide among
Blautia
species, expanding our understanding of this well-known glycan. Our approach can be applied to identify consumers of understudied glycans and expand our prebiotic repertoire. It can also be used to study prebiotic glycans directly in stool samples in distinct patient populations to help delineate the prebiotic mechanism.
Development of monoclonal antibodies against
P. gingivalis
Mfa1 and their protective capacity in an experimental periodontitis model
Authors: Cao Mingya , Wang Siyu , Zhou Shengke , Yan Min , Zou Yu , Cui Yuan , Lou Xinyu , Gao Yichang , Chen Ying , Han Zijing , Qian Yi , Chen Jingying , Li Xia
Published: December 2024

Porphyromonas gingivalis
(
P. gingivalis
), a gram-negative, black-pigmented anaerobe, is a major etiological agent and a leading cause of periodontitis. Fimbriae protein Mfa1 is a key virulence factor of
P. gingivalis
and plays a crucial role in bacterial adhesion, colonization, biofilm formation, and persistent inflammation, making it a promising therapeutic target. However, the role of anti-Mfa1 antibodies and the underlying protective mechanisms remain largely unexplored. Here, we developed and characterized the monoclonal antibodies (mAbs) targeting the Mfa1 protein of
P. gingivalis
. Function analysis showed that anti-Mfa1 mAbs mediated bacterial agglutination and inhibited
P. gingivalis
adhesion to saliva-coated hydroxyapatite and host cells. Notably, anti-Mfa1 mAbs significantly reduced bacterial burden and alveolar bone loss in a
P. gingivalis
-induced experimental periodontitis model. These results show that anti-Mfa1 mAbs can be beneficial in alleviating
P. gingivalis
infections, and provide important insights for the development of adequate adjuvant treatment regimens for Mfa1-targeted therapeutics.

IMPORTANCE

Fimbriae (pili) play an important role in bacterial adhesion, invasion of host cells and tissues, and formation of biofilms. Studies have shown that two types of fimbriae of
Porphyromonas gingivalis
, FimA and Mfa1, are important for colonization and infection through their binding to host tissues and other bacteria. While anti-FimA antibodies have been shown to improve periodontitis, the effect of anti-Mfa1 antibodies on
P. gingivalis
infection and periodontitis was previously unknown. In this study, we report for the first time that anti-Mfa1 monoclonal antibodies can reduce
P. gingivalis
infection and improve periodontitis. These findings suggest that Mfa1 represents a promising therapeutic target, and the development of anti-Mfa1 mAbs holds a potential as essential diagnostic and adjunctive therapeutic tools for managing
P. gingivalis
-related diseases.
Multi-level analysis of gut microbiome extracellular vesicles-host interaction reveals a connection to gut-brain axis signaling
Authors: Mottawea Walid , Yousuf Basit , Sultan Salma , Ahmed Tamer , Yeo JuDong , Hüttmann Nico , Li Yingxi , Bouhlel Nour Elhouda , Hassan Hebatoallah , Zhang Xu , Minic Zoran , Hammami Riadh
Published: December 2024

Microbiota-released extracellular vesicles (MEVs) have emerged as a key player in intercellular signaling. However, their involvement in the gut-brain axis has been poorly investigated. We hypothesize that MEVs cross host cellular barriers and deliver their cargoes of bioactive compounds to the brain. In this study, we aimed to investigate the cargo capacity of MEVs for bioactive metabolites and their interactions with the host cellular barriers. First, we conducted a multi-omics profiling of MEVs’ contents from
ex vivo
and stool samples. Metabolomics analysis identified various neuro-related compounds encapsulated within MEVs, such as arachidonyl-dopamine, gabapentin, glutamate, and N-acylethanolamines. Metaproteomics unveiled an enrichment of enzymes involved in neuronal metabolism, primarily in the glutamine/glutamate/gamma-aminobutyric acid (GABA) pathway. These neuro-related proteins and metabolites were correlated with
Bacteroides
spp. We isolated 18
Bacteroides
strains and assessed their GABA production capacity in extracellular vesicles (EVs) and culture supernatant. A GABA-producing
Bacteroides finegoldii
, released EVs with a high GABA content (4 µM) compared to
Phocaeicola massiliensis
. Upon testing the capacity of MEVs to cross host barriers, MEVs exhibited a dose-dependent paracellular transport and were endocytosed by Caco-2 and hCMEC/D3 cells. Exposure of Caco-2 cells to MEVs did not alter expression of genes related to intestinal barrier integrity, while affected immune pathways and cell apoptosis process as revealed by RNA-seq analyses.
In vivo
, MEVs biodistributed across mice organs, including the brain, liver, stomach, and spleen. Our results highlight the ability of MEVs to cross the intestinal and blood-brain barriers to deliver their cargoes to distant organs, with potential implication for the gut-brain axis.

IMPORTANCE

Microbiota-released extracellular vesicles (MEVs) have emerged as a key player in intercellular signaling. In this study, a multi-level analysis revealed presence of a diverse array of biologically active molecules encapsulated within MEVs, including neuroactive metabolites, such as arachidonyl-dopamine, gabapentin, glutamate, and N-acylethanolamines, and gamma-aminobutyric acid (GABA). Metaproteomics also unveiled an enrichment of neural-related proteins, mainly the glutamine/glutamate/GABA pathway. MEVs were able to cross epithelial and blood-brain barriers
in vitro
. RNA-seq analyses showed that MEVs stimulate several immune pathways while suppressing cell apoptosis process. Furthermore, MEVs were able to traverse the intestinal barriers and reach distal organs, including the brain, thereby potentially influencing brain functionality and contributing to mental and behavior.
Phillyrin ameliorates DSS-induced colitis in mice via modulating the gut microbiota and inhibiting the NF-κB/MLCK pathway
Authors: Li Tong , Hu Guiqiu , Fu Shoupeng , Qin Di , Song Zheyu
Published: December 2024

Phillyrin (PHY), also known as forsythin, is an active constituent isolated from the fruit of
Forsythia suspensa
(Thunb.) Vahl (Oleaceae). It exhibits anti-inflammatory, anti-viral, and antioxidant properties. However, the precise impact of PHY on colitis induced by dextran sodium sulfate (DSS) and its mechanism remain elusive. The present investigation revealed that PHY (12.5, 25.0, and 50.0 mg/kg) exhibited significant therapeutic efficacy in protecting mice against DSS-induced colitis. This effect was manifested as reduced weight loss, a shortened colon, increased secretion of inflammatory factors, increased intestinal permeability, and an enhanced disease activity index in mice with ulcerative colitis (UC). Molecular investigations have determined that PHY mitigates the nuclear translocation of nuclear factor kappa B, thereby downregulating myosin light-chain kinase-driven myosin light-chain phosphorylation. This mechanism results in the preservation of the integrity of the intestinal barrier. The outcomes of 16S rRNA sequencing suggest that PHY (50 mg/kg) augmented the relative abundance of certain probiotic strains, including
Lactobacillaceae
and
Lachnospiraceae
. Additionally, PHY supplementation elevated the short-chain fatty acid contents within the intestinal contents of mice with UC. In conclusion, pre-treatment with PHY may ameliorate the DSS-induced UC in mice by lowering the expression of inflammatory factors, protecting intestinal barrier function, and enhancing the structure of the intestinal flora.

IMPORTANCE

The protective effect of phillyrin on DSS-induced colitis was explained for the first time, and the anti-inflammatory effect of phillyrin was demonstrated by fecal microbiota transplantation experiments mainly through intestinal flora.
Effect of colistin-tigecycline combination on colistin-resistant and carbapenem-resistant
Klebsiella pneumoniae
and
Acinetobacter baumannii
Authors: Park Suyeon , Jin Yanhong , Ko Kwan Soo
Published: December 2024

There is a critical need for treatment strategies to combat carbapenem-resistant Gram-negative pathogens. This study investigates the efficacy of combining low concentrations of colistin with tigecycline against colistin- and carbapenem-resistant
Klebsiella pneumoniae
and
Acinetobacter baumannii
strains. We used two strains of KPC-2-producing
K. pneumoniae
and OXA-23-producing
A. baumannii
, both of which are highly colistin-resistant. In the
in vitro
time-killing assays, monotherapy with colistin (2 mg/L) and tigecycline (4 or 8 mg/L) was ineffective against all strains. However, the combination of colistin (2 mg/L) and tigecycline (4 or 8 mg/L) inhibited bacterial growth. Survival analysis of
Galleria mellonella
larvae also demonstrated the efficacy of low concentrations of colistin and tigecycline against colistin- and carbapenem-resistant strains. All larvae survived when treated with a combination of colistin and tigecycline, whereas monotherapy with either colistin or tigecycline did not increase larval survival rates. This study proposes using a combination of tigecycline and colistin at clinical concentrations to treat carbapenem-resistant
K. pneumoniae
and
A. baumannii,
regardless of colistin resistance.

IMPORTANCE

Colistin resistance in carbapenem-resistant Gram-negative pathogens is a serious challenge in clinical settings. Our study showed that low concentration of colistin can be effective when combined with tigecycline. It presents the possibility of an available treatment option for antibiotic-resistant pathogens.
Research on a New High-Damping Viscoelastic Damper: Development, Experiment and Modeling
Authors: Liang Chen , Yuan Yong , Yu Xiao-Tao
Published: December 2024

Viscoelastic (VE) dampers are promising control devices for mitigating the vibration of structures. The performance of these dampers depends on the energy dissipation and deformation capability of VE materials. This paper aims to develop a VE damper with high damping to improve the energy dissipation performance of existing dampers. A new VE material with high damping was developed and tested for its shear mechanical properties. A total response control viscoelastic (TRC-VE) damper was designed and manufactured using the new high-damping VE material. The performance of the TRC-VE damper was comprehensively investigated in terms of strain, frequency and size dependence. A five-element shear mechanical model was proposed to simulate the shear mechanical behavior of the TRC-VE damper. Results indicated that the TRC-VE damper has remarkable energy dissipation and excellent deformation capacities. The five-element shear mechanical model can accurately simulate the shear mechanical properties of the new high-damping TRC-VE damper.
Machine Learning-Aided Cloud-Based Robust Image Cryptography with Lupus Coyote Optimization for Enhanced Performance
Authors: Parvathraj K. M. M. , Anoop B. K.
Published: December 2024

To ensure the confidentiality of the data that are transferred over cloud networks including sensitive information like medical images and money transaction is significant and requires severe security mechanism to protect the personal information from hackers as well as malicious users as breaches in security affect the privacy and reputation of the user. Hence, an image-based cryptographic method is developed for improving security performance. Here, the time-bound encryption approach is established for protecting confidential medical images which is implemented in e-healthcare. Further, it traverses through a Lupus Coyote optimization (LCO) algorithm which utilizes the systematic chaotic maps (CM), since it performs based on the parameters which may be either discrete or consistent time parameters, and the inception of chaotic signals prevents the prohibited accesses. The proposed LCO optimizes the process of pixel assembling by determining the right parameter values for formulating the chaotic patterns to provide a robust cryptography method. Finally, the permutation as well as the properties of diffusion is controlled in the entire system to deal with the complexity of control pixel shuffling as well as the operations of substitution. Additionally, the correlation between neighboring pixels is interrupted which adds complexity to extracting the information by the attackers and the diffusion algorithm assists in eliminating the storage issue. Thus, the performance of the LCO-based time bound image encryption using the CM model is improved than the other systems, in which the performance metrics such as cosine similarity (CS), histogram correlation (HC), mean square error (MSE), peak signal to noise ratio (PSNR), root mean square error (RMSE), and structural similarity index measure (SSIM) attained the values of 86.53, 0.935, 4.12, 39.51, 4.54, and 0.94 dB, respectively, at number of images 50 with the size of population 250.
Matrix elements and characters of the discrete series (“massive”) unitary irreducible representations of Sp(4, ℝ)
Authors: Gazeau Jean-Pierre , del Olmo Mariano A. , Pejhan Hamed
Published: December 2024

This paper obtains the matrix elements and characters of the discrete series unitary irreducible representations (UIRs) of the Sp[Formula: see text] group. With an isomorphic relationship to the two-fold covering of [Formula: see text] ([Formula: see text][Formula: see text]), this group holds particular importance as the kinematical/relativity group within the framework of ([Formula: see text]-dimensional) anti-de Sitter spacetime.
Analysis of heat transfer in magnetized Williamson fluid over a porous curved oscillating surface: Entropy generation
Authors: Imran M. , Naveed M. , Waheed Rasheed Muhammad
Published: December 2024

This paper provides an innovative idea to perform the analysis of entropy generation in the time-dependent flow of Williamson liquid toward an oscillating curvy porous surface. The characteristics of the transport phenomenon are improved by taking thermal and mass relaxation parameters in the energy and concentration equations respectively by utilizing a modulated form of Fourier and Fick laws known as Cattaneo–Christov heat and mass flux models. The mathematical form of the entire flow model is simplified by incorporating a curvilinear coordinate system. The obtained set of partial differential equations is then solved by the homotopy analysis method (HAM) which transforms them into convergent series form. The effects of various pertinent flow parameters on dimensionless pressure, entropy generation, velocity, and temperature fields are shown graphically. Furthermore, the variations in Sherwood number, skin friction coefficient, and local Nusselt number are presented in tabular form. It is observed from this study that the temperature and entropy generation increase with the radius of curvature parameter.
Multiple normalized solutions for Choquard equation involving the biharmonic operator and competing potentials in ℝN
Authors: Liang Shuaishuai , Ma Jiaying , Shi Shaoyun , Song Yueqiang
Published: December 2024

This paper is concerned with the existence of multiple normalized solutions for a class of Choquard equation involving the biharmonic operator and competing potentials in [Formula: see text]: [Formula: see text] where [Formula: see text] is the biharmonic operator, [Formula: see text], [Formula: see text], [Formula: see text] is an unknown parameter that appears as the Lagrange multiplier, the absorption potential [Formula: see text], reaction potential [Formula: see text] and nonlinear term [Formula: see text] are continuous functions and satisfy some assumptions. With the help of the minimization techniques and Lusternik–Schnirelmann category, we show that the number of normalized solutions is not less than the number of global minimum points of [Formula: see text] when the parameter [Formula: see text] is sufficiently small. Furthermore, and more interestingly, we can prove the existence of multiple solutions for this problem by using the Morse theory. As far as we know, this study seems to be the first contribution regarding the concentration behavior for Choquard equation involving the biharmonic operator.
Semantic Feature Graph Consistency with Contrastive Cluster Assignments for Multilingual Document Clustering
Authors: Sun Teng , Shu Zhenqiu , Huang Yuxin , Wang Hongbin , Yu Zhengtao
Published: December 2024

Multilingual document clustering (MDC) aims to partition multilingual documents into distinct clusters based on topic categories in an unsupervised manner. However, existing MDC methods still suffer from several limitations in practice tasks. Firstly, most of them optimize multiple objectives within the same feature space, thereby leading to the conflict between learning consistently shared semantics and reconstructing inconsistent view-specific information. Secondly, several methods directly integrate information from multilingual documents during the fusion stage, thereby overlooking the semantic differences between different language features. To address the aforementioned problems, we propose a novel multi-view learning method, called Semantic Feature Graph Consistency with Contrastive Cluster Assignments (SFGC
3
A), for MDC. Specifically, the proposed SFGC
3
A method implements consistency objective and reconstruction objective in different feature spaces, thus effectively avoiding conflicts between consistency learning and inconsistency reconstruction. Subsequently, we design the semantic feature graph consistency and semantic label consistency modules to further explore consistent semantic information among multilingual documents, thereby reducing the semantic differences among different language views. Extensive experiments on several multilingual document datasets have shown the effectiveness of the proposed SFGC
3
A method in MDC tasks. The source codes for this work will be released later.
Model-Free Deep Reinforcement Learning for Adaptive Supply Temperature Control in Collective Space Heating Systems
Authors: Ghane Sara , Jacobs Stef , Huybrechts Thomas , Hellinckx Peter , Mercelis Siegfried , Verhaert Ivan , Mannens Erik
Published: December 2024

The conventional approach for controlling the supply temperature in collective space heating networks relies on a predefined heating curve determined by outdoor temperature and heat emitter type. This prioritises thermal comfort but lacks energetic and financial optimisation. This research proposes an adaptive supply temperature control in well-insulated dwellings, responsive to diverse environmental parameters. The approach considers variable electricity prices and accommodates different indoor temperature set points in dwellings. The study evaluates the effectiveness of two Deep Reinforcement Learning (DRL) algorithms, i.e., Proximal Policy Optimisation (PPO) and Deep Q-Network (DQN), across various scenarios. Results reveal that DQN excels in collective space heating systems with underfloor heating in each dwelling, while PPO proves superior for radiator-based systems. Both outperform the traditional heating curve, achieving up to 13.77% (DQN) and 16.15% (PPO) cost reduction while guaranteeing thermal comfort. Additionally, the research highlights the capability of DRL-based methods to dynamically set the supply temperature based on a cloud of set points, showcasing adaptability to diverse environmental factors and addressing the growing significance of indoor heat gains in well-insulated dwellings. This innovative approach holds promise for more efficient and environmentally conscious heating strategies within collective space heating networks.
Imaging and Nonsurgical Management of Renal Masses
Authors: Jorgenson Laura C. , Navin Patrick J. , Adamo Daniel , Thompson Scott , Takahashi Edwin , Schmit Grant , Potretzke Theodora , Venkatesh Sudhakar K. , Potretzke Aaron M. , Stish Bradley , Atwell Thomas D.
Published: December 2024

Radiologists play a key role in the management of renal masses, and it is important to understand the nonsurgical treatment options for solid renal masses, typical imaging findings after treatment, common complications, and methods to avoid pitfalls.
(Invited) The Potential of Pulsed Low Temperature Plasmas for the Controlled Deposition of Plasma Polymer Ultrathin Films and Composite Nanomaterials (Invited)
Authors: Berndt Johannes
Published: December 2024

Low temperature discharges with their unique non-equilibrium properties are often used in industrial processes for the deposition of ultra-thin (plasma) polymer films. Applications for this type of thin films range from protective coatings to their use in membranes, biosensors and batteries. However, the properties of these thin films are highly dependent on the choice of discharge parameters, both in terms of their surface topography and their chemical composition. This paper deals with the great potential of pulsed discharges for the controlled deposition of plasma polymer films. The influence of pulse frequency and duty cycle on the deposition process and the properties of the resulting thin films is discussed from a theoretical point of view and is illustrated by experimental results. The latter concern examples of experiments carried out with discharges operated with acetylene or aniline, as well as functional coatings on top of MoS2, 2D graphene or CNTs.

The work was supported by the project PEGASUS (Plasma Enabled and Graphene Allowed Synthesis of Unique nano-structures), funded by the European Union’s Horizon research innovation program under Grant Agreement No. 766894; EU Graphene Flagship FLAG-ERA III JTC 2021 project VEGA (No. PR-11938) Project-ANR-21-GRF1-0004. Further support was obtained via ARD MATEX Centre-Val de Loire Region (projects Carbon2 and Carbon3) and project Orleans Metropole (both France).
(Invited) Recent Developments in Solid-State Lithium-Metal Technology at Quantumscape
Authors: Winterkorn Martin M
Published: December 2024

Conventional lithium-ion batteries fall short of meeting the needs of many automotive, consumer electronics, and stationary storage applications. QuantumScape is developing a solid-state battery with a lithium-metal anode to enable longer-range, faster charging and enhanced safety. The technology features an anode that is manufactured without excess lithium with the lithium being delivered entirely from the cathode material. In this talk, Dr. Martin M. Winterkorn will highlight recent developments in solid-state lithium-metal technology and review some of the challenges in transitioning from R&D to a commercial product.
Water Splitting through Electrochemical Catalyst of Iridium-Based Transition Metal Alloy Nanoparticles on Oxide Supports
Authors: Song Jeongeun , Han Kyeongwon , Kim Hyungjin , Kim Seulgi , Park Hyeonji , Jeon Yukwon
Published: December 2024

Electrochemical water splitting is critical to produce green hydrogen without greenhouse gas emissions. Iridium-based catalysts are important for increasing the oxygen evolution reaction (OER) efficiency of water splitting, but their high cost and scarcity require the development of new electrodematerial structure. Alloyed nanoparticles have modified electrochemical structure for improved OER activity andstable support such as perovskite oxide can be applied due to its high oxygen transfer rate. This research focuses on developing iridium-transition metal alloy nanoparticles on a stable perovskite support to improve OER performance and durability. The changes in particle size, composition, and temperature-controlled structure are the main research topics, highlighting balancing activity and economics to produce hydrogen in an environmentally friendly way.
Layered Manganese Dioxide Intercalated with Copper Ions for Electrochemical Reduction of Nitrate to Ammonia
Authors: Yoshida Wataru , Fukuhara Hiroyasu , Nakayama Masaharu
Published: December 2024

Electrochemical nitrate reduction reaction (NO3RR) offers a new pathway for low-temperature green ammonia synthesis. Here, we prepared a thin film of layered MnO2, the interlayer of which accommodates Cu2+ ions coordinated with water molecules. The process consisted of electrodeposition of layered MnO2 intercalated with tetrabutylammonium cations (TBA+) by anodic oxidation of aqueous Mn2+ ions in the presence of TBA+, followed by ion exchange of the initially incorporated bulkier TBA+ with the Cu2+ ions in solution. The resulting layered MnO2 intercalated with Cu2+ ions (Cu2+/MnO2) supported on a FTO substrate was applied to electrochemical NO3RR. In the potentiostatic reduction at –0.7 V vs RHE in NaOH electrolyte, the Cu2+/MnO2 electrode catalyzed NO3RR with higher faradic efficiency for ammonia formation than Cu plating electrode. X-ray diffraction spectroscopy indicated that the structure of layered MnO2 was maintained during NO3RR. In addition, linear sweep voltammogram and X-ray photoelectron spectroscopy suggested the electrochemical reduction of the Cu2+ ions between MnO2 layers and in situ generation of metallic Cu particles prior to NO3RR.

Figure 1
Pd-Based Metal-Support Heterostructure Catalyst for High Performance Electrocatalytic N2 Reduction Reaction
Authors: Song Ji-Yoon , Park Jaehyun , Jung Hee-Tae
Published: December 2024

Electrocatalytic nitrogen (N2) reduction reaction (eNRR) is of great interest to produce the green ammonia (NH3). However, the competitive side reaction of hydrogen (H2) evolution reaction (HER) and slow proton-couple electron transfer (PCET) step still become a bottleneck where resulting in poor N2 selectivity and yield of NH3 production. The heterostructures of metal and boron nitride (BN) analogs have been computatively demonstrated and suggested as a potential eNRR catalyst to improve eNRR performance as both suppressing HER and accelerating PCET step. However, experimental demonstration is still challenging due to the complex synthetic method required to achieve a uniform and dense distribution of metal catalysts on the BN surface.

Here, we present the facile and uniform formation of the Pd nanoparticles (NPs) on defective boron nitride (BN) using ultrafast radiative Joule-heating within short time (~0.5 s), which is the first-time demonstration on the BN family. Especially, thanks to the strong electronic metal-to-support interaction (EMSI) effect between the defect site of BN surface and Pd NPs, the electron-deficient state of Pd NPs facilitates the significant reduce of free energy during the PCET step which is beneficial to interact with N2 molecules. In particular, we observe that Pd NPs on defective BN support exhibit the high NH3 selectivity of 68% in the neutral aqueous electrolyte and 59% of NH3 selectivity and 53.3 µg/h/cm2 of NH3 yield rate in the acidic media, respectively, which are the highest values of the selectivity and NH3 yield rate among existing Pd-based eNRR catalysts.
Influence of Solvents on Catalyst Layer Performance in Proton Exchange Membrane Water Electrolysis and Fuel Cells
Authors: Park Jong-Hyeok , Park Yeri , Park Jin Soo
Published: December 2024

Proton exchange membrane (PEM) water electrolysis (WE) and fuel cells (FCs) stand out as promising technologies for hydrogen generation and utilization, leveraging renewable and sustainable energy sources. A pivotal element in both PEMFC and PEMWE is the membrane-electrode assembly (MEA), comprising catalyst layers (CLs) and a membrane. These CLs facilitate electrochemical reactions at the anode and cathode, crucial for both oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) in PEMWE and PEMFC. The catalyst ink for CLs consists of electrocatalyst, ionomer dispersion, and additional solvents. Among these components, the choice of solvent significantly influences PEMFC and PEMWE performance, shaping the catalyst ink's properties. In this investigation, we formulated ionomer dispersions for CLs to enhance performance in PEMWE and PEMFC. We scrutinized the effects of solvents in terms of solvation energy, thermogravimetric analysis (TGA), particle size distribution (PSD), and electrochemical assessment.

Acknowledgments

This research was supported in part by the New and Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20213030040520) and by 2021 Green Convergence Professional Manpower Training Program of the Korea Environmental Industry and Technology Institute funded by the Ministry of Environment.
(Invited) In Situ Measurements during ALD/ALE Processes
Authors: Elam Jeffrey W.
Published: December 2024

Atomic layer deposition (ALD) and atomic layer etching (ALE) provide exquisite control over the addition and removal of thin film materials and are invaluable tools for semiconductor manufacturing and a wide range of other applications. However, it is not always clear why some ALD/ALE processes succeed while others fail. Performing in situ measurements during ALD/ALE can unravel the detailed surface chemistries underlying these processes to elucidate the reaction mechanisms and ultimately yield more robust and reliable processes. In this presentation, I will motivate the need for in situ measurements during ALD/ALE and provide detailed examples of the techniques used under typical ALD conditions including quartz crystal microbalance, mass spectrometry, infrared spectroscopy, spectroscopic ellipsometry, and optical emission spectroscopy for plasma-based processes. I will also describe some of the high vacuum in situ methods that have been exploited such as X-ray photoelectron spectroscopy and scanning probe microscopy. In addition, I will discuss synchrotron X-ray based methods for in situ study of ALD/ALE reactions.
Enhancing Efficiency and Stability with Composite Oxygen Electrodes in Protonic Ceramic Electrochemical Cells
Authors: Duan Chuancheng
Published: December 2024

Composite oxygen electrodes in protonic ceramic electrochemical cells (PCECs) present a range of significant benefits that enhance both performance and durability. Our research lab has shown that these electrodes can simultaneously boost electrocatalytic activity, stability, and mechanical properties. Such improvements result in more effective and robust PCECs, broadening their applicability in diverse sectors, including energy conversion and storage systems. This presentation will highlight the innovative composite air electrode developed by our team and explore its advantages.
Designing an Ammonia Compatible SOFC System
Authors: Huhtinen Werneri , Saxelin Santeri , Kiviaho Jari , Himanen Olli
Published: December 2024

Ammonia (NH3) as a fuel in Solid Oxide Fuel Cell (SOFC) systems for marine applications is a promising approach towards carbon-neutral power generation. Ammonia offers distinct advantages over liquefied hydrogen in terms of handling, storage, and existing distribution infrastructure.

In single cell testing, ammonia has been recognized as a potential fuel for SOFC stacks, demonstrating comparable performance to other fuels such as pure hydrogen and natural gas-based reformates. The nickel containing fuel electrodes of fuel cells, facilitate the decomposition of ammonia feed into nitrogen and hydrogen. Hydrogen is then utilized as a fuel for the power generating electrochemical reaction.

However, challenges arise at the stack level when using ammonia, particularly concerning the use of state-of-the-art steel grades as interconnect plate materials. The high-temperature decomposition of ammonia generates highly reactive N3- ions, leading to nitridation reactions that degrade steel structures, impacting electrode contacts, and potentially resulting in significant performance losses and mechanical cracking of cells.

This study introduces three approaches aimed at advancing the design and development of an ammonia compatible SOFC system. Ex-situ material testing was conducted to assess the material tolerances of common metals used in SOFC systems. The results provide insights for material selection and component development. Secondly, to gather comprehensive data on stack durability and degradation in an ammonia-containing environment, stack-level performance testing was performed using simulated pre-cracked ammonia feeds as the fuel for a 350 W SOFC short stack.

Lastly, ensuring sufficient pre-cracking of ammonia is crucial for maintaining the durability of ammonia fueled SOFCs, as high concentrations of raw ammonia can lead to shortened lifespans. Thus, performance mapping of multi-fuel processing capable nickel catalyst was done at various temperatures. This led to the determination of optimal operating conditions for the highly endothermic ammonia cracking reaction, which could be sustained by the excess heat from the SOFC system.

This study combines laboratory-scale experimental results from ex-situ material testing, stack-level durability experiments, and catalyst performance mapping for the cracker unit. These findings establish design parameters for the development of an upscaled ammonia compatible SOFC system.

Acknowledgment

This research was financially supported by the European Union’s Horizon Europe research and innovation programme under the grant agreement No 101069828 (project FuelSOME).
Bipolar Membrane (BPM)-Based Direct Seawater Electrolysis
Authors: Han Ji-Hyung , Shin Hye Kyoung , Jeong Namjo , Eom Hyunji , Lee Jung Jae
Published: December 2024

I will introduce direct seawater electrolysis with a bipolar membrane (BPM) as a separator for controlling inorganic precipitates. Seawater is acidified to pH 2 despite the significant generation of hydroxide ions in the hydrogen evolution reaction (HER). This acidification results from the cooperative effect of hydroxide ions trapped by inorganic precipitates at the cathode and proton flux from water dissociation in the BPM. The acidified seawater continuously dissolves the Mg(OH)2 formed on the cathode surface, keeping the deposits very thin. In addition, the thermodynamic potential of the HER moves in the positive direction, which has the advantage of decreasing the cell voltage. Using Brunauer–Emmett–Teller (BET) analysis, water vapor sorption, and electrochemical impedance analysis, it is confirmed that the Mg(OH)2 film has a hierarchical mesoporous structure and high affinity for water, which maintained mass transport. The unique properties of the Mg(OH)2 film under seawater acidification contributes to a lower rate of increase in the cathodic potential than that under seawater alkalization, where very thin inorganic deposits are formed.
Demonstration of Converting Blast Furnace Gas to High Purity Hydrogen
Authors: Flynn Eric , Reinartz Stefan
Published: December 2024

This paper reports on a novel technology, eXEROTM, that is being utilized in a demonstration project at an integrated steelworks in North America to produce hydrogen from blast furnace gas in a single process step. The paper provides an overview of the technology, the project implementation, and results obtained from the field trial.

Global average temperatures for the 12 months between June 2023 and May 2024 were the highest on record. The continuing warming of our atmosphere heightens the need for decarbonization of existing infrastructure and industrial processes like steel making. With a growing demand for low carbon intensity hydrogen, conventional methods of production face obstacles involving substantial electricity inputs, infrastructure, and CAPEX, which can conflict with operational and business objectives. Our reactor has proven to be an attractive option for existing plant operations by eliminating the need for significant electricity inputs and infrastructure.

The zero-electricity electrolysis technology, trademarked eXEROTM, is based on two gas streams, which are separated by an impermeable electrolyte, and counter-exchange of oxygen ions and electrons. Thus, one of the streams undergoes reduction while the other stream simultaneously undergoes oxidation. Unlike traditional fuel cells or electrolyzers, no current is extracted or delivered to the reactor to drive the process. The overall redox reaction is thermodynamically driven by the different gas compositions across the anode and cathode of the cell, fundamentally described by the Nernst Equation. A mixed conducting electrolyte is used to transport electrons from the anode to the cathode and oxygen ions from the cathode to the anode in the eXERO technology platform. Therefore, with certain chemical compositions at the anode, steam in the cathode will spontaneously dissociate into hydrogen ions and oxygen ions without an external circuit. Like in a traditional solid oxide electrolyzer with an applied external overpotential, electrons flow concurrently from the anode to the cathode, forming hydrogen at the cathode.

A demonstration plant utilizing the eXERO technology was designed, fabricated, installed, and commissioned on an operating steel mill facility. The paper includes information pertaining to operational results under actual plant conditions, the impact of industrial feedstocks, and other challenges. Data on the hydrogen produced by the eXERO technology will be covered along with the relevance of utilizing the technology to generate clean hydrogen from blast furnace gas, in order to decarbonize integrated steel production.

The significance of this milestone for improving industrial processes, mitigating greenhouse gases and creating multiple paths to an effective and affordable energy transition is significant. To our knowledge, this is the first time this direct conversion has been achieved. It represents a much better way for heavy industries to reach environmental and business objectives.
(Invited) Organic Transformations with Strongly Photoreducing Catalysts
Authors: You Youngmin
Published: December 2024

The recent advances of synthetic methodologies benefit from molecular photoredoxcatalysis. Molecular photoredox catalysts offer particular advantages in steering reactions that involve key radical intermediates, as they enable large exoergicity for generating radical species under ambient conditions through heterobimolecular photoinduced electron transfer. To expand the catalytic potential, my group investigated photoinduced electron transfer of doublet molecules and electron-rich, low-valent metal complexes. We found that radical anions of organic molecules exhibited strong photoreducing power capable of generating synthetically important aryl radical intermediates from aryl halides which reacted with aryl boronate esters to produce C-C cross-coupled products. Our studies provided convincing evidence that the active catalyst species was the excited-state radical anion which could be generated through consecutive absorption of a photon, an electron, and another photon. In particular, femto- and nanosecond transient absorption spectroscopic investigations provided direct evidence for the generation and oxidative quenching of the excited-state radical anion. As an alternative strategy to utilize the strong photoreducing power of a molecular catalyst, we seek electron-rich, low-valent transition metal complexes as photoredoxcatalysts. Our exploration enabled us to identify heteroleptic, linear Au(I) complexes as potent photoreducing catalysts with an excited-state oxidation potential as cathodic as -2.23 V vs standard calomel electrode. These Au(I) complexes can catalyse heteroaryl C-C cross-coupling reactions of redox-resistant aryl chlorides. Our investigations demonstrate that the Au(I) complexes offer several benefits, including strong visible-light absorption, a long excited-state lifetime, and the capacity of a 91% yield in the production of free-radical intermediates.
(Invited) Development of a New Biopolar Electrode Array and Coreactant for High-Performance Electrochemiluminescence Field Diagnostic Device
Authors: Cho young Kwan , Jeon Sang-Hyun , Kim Hyunho , Shim Beom-Jun , Lee Hakho , Shin Ik-Soo
Published: December 2024

Biomarkers in the human body and complex matrices such as blood, urine, and tissues are powerful aids in clinical diagnosis and treatment monitoring. Detection, identification, and quantification of these molecules requires development of sophisticated methods and complexed instruments. Yet, disease-related biomarkers are often present in trace amounts around picomolar levels, and their assay still faces a technical limitation that only large central lab-based instrumentations are allowed. Various analytical methods, such as surface-enhanced raman spectroscopy, amperometric detection Using electrocatalyst, or inter- (or intra-) molecularly optical energy transfer, have been proposed as ways to address the challenge but are still a significant technological distance away from application in the real world. In this context, electrochemiluminescence (ECL) Is a leading detection technique due to its optimal combination of electrochemical and spectroscopic Methods. Recently, we developed an innovative bipolar electrode array and detection protocol and successfully applied these to diagnosing diseases requiring various medical environments, from COVID-19 and Sepsis to colorectal cancer. In the talk, I will give a brief introduction to this.
Exploring Novel Minimal-Catalyst Glucose to CO2 Pathways for Hybrid Enzymatic Biofuel Cell Development
Authors: Milam Adam , Gerulskis Rokas
Published: December 2024

Biological fuel (Biofuel) cells employ biocatalysts to perform redox reactions, converting the chemical energy in a substrate into electrical energy. Glucose is an excellent substrate for biofuel cells due to its bioavailability for implanted devices and because the catalysts involved in its breakdown in vivo, which may be isolated and employed in a fuel cell, are relatively well characterized. Enzymatic glucose fuel cells in literature often catalyze only one to two of twelve possible oxidation steps in the complete oxidation of glucose to CO2 due to issues with multi-enzyme systems, including pH incompatibilities, cross-inhibition between reactions, and competition for electrode surface area. Molecular electrocatalysts such as 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) demonstrate superior substrate scope and electron transfer kinetics in oxidation reactions. We demonstrate the use of 4-amino-TEMPO as an oxidative catalyst to replace four of the six enzymes from a previously established enzymatic glucose to CO2 cascade. The proposed hybrid cascade is supported by NMR and MS detection of intermediate and terminal products.