bluuebunny/crossref_metadata_2025_split huggingface dataset:
C3‐Symmetric Luminescent Diketone with Amido‐Linkage as a Polymorphic Fluorescence Emitter
Authors: Katsumi Shiho , Kugai Yusuke , Louis Marine , Morimoto Tsumoru , Yamada Mihoko , Maisonneuve Stéphane , Goto Chigusa , Métivier Rémi , Kawai Tsuyoshi , Allain Clémence 
Published: February 2024

AbstractThe study introduces a novel C3‐symmetric β‐diketone compound, BTA‐D3, and its monomeric counterpart, D, with a focus on their synthetic procedure, photophysical properties and aggregation behavior. Both compounds exhibit characteristic absorption and weak fluorescence in solution, with BTA‐D3 displaying higher absorption coefficients due to its larger number of diketone units. Density Functional Theory (DFT) calculations suggest increased co‐planarity of diketone groups in BTA‐D3. A significant finding is the Aggregation‐Induced Emission (AIE) property of BTA‐D3, as its fluorescence intensity increases dramatically when exposed to specific solvent ratios. The AIE behavior is attributed to intermolecular excitonic interaction between BTA‐D3 molecules in self‐organized aggregates. We also studied fluorescence anisotropy of BTA‐D3 and D. Despite its larger size, BTA‐D3 showed reduced anisotropy values because of efficient intramolecular energy migration among three diketone units. Furthermore, BTA‐D3 demonstrates unique polymorphism, yielding different emission colors and structures depending on the solvent used. A unique approach is presented for promoting the growth of self‐organized aggregate structures via solvent evaporation, leading to distinct fluorescence properties. This research contributes to the understanding of C3‐symmetric structural molecules and provides insights into strategies for controlling molecular alignment to achieve diverse fluorescence coloration in molecular materials.
Synthesis and Structure of the Small Superelectrophile [C2(OH)2Me2]2+
Authors: Virmani Alan , Jessen Christoph , Kornath Andreas J. 
Published: February 2024

AbstractThe acid‐activation of 1,2‐dicarbonyl compounds plays a key role in a variety of electrophilic reactions, some of which are only accessible in superacidic media when a superelectrophilic dication is formed. To obtain structural and electronic information about these elusive species, the vicinal dication [C2(OH)2Me2]2+ is synthesized and characterized by Raman spectroscopy and X‐ray diffraction. Since this superelectrophile could not be stabilized in convenient superacids, the usage of liquid SO2 turned out to be crucial. The experimental data are discussed together with quantum‐chemical calculations on the B3LYP/aug‐cc‐pVTZ level of theory. Natural Bond Orbital (NBO) analyses quantify the superelectrophilic interactions found in the solid state.
Cationic Hypervalent Chalcogen Bond Catalysis on the Povarov Reaction: Reactivity and Stereoselectivity
Authors: Zhao Chang , Li Ying , Wang Yanjiang , Zeng Yanli 
Published: February 2024

AbstractChalcogen bond catalysis, particularly cationic hypervalent chalcogen bond catalysis, is considered to be an effective strategy for organocatalysis. In this work, the cationic hypervalent chalcogen bond catalysis for the Povarov reaction between N‐benzylideneaniline and ethyl vinyl ether was investigated by density functional theory (DFT). The catalytic reaction involves the cycloaddition process and the proton transfer process, and the rate‐determining step is the cycloaddition process. Cationic hypervalent tellurium derivatives bearing CF3 and F groups exhibit superior catalytic activity. For the rate‐determining step, the Gibbs free energy barrier decreases as the positive electrostatic potential of the chalcogen bond catalysts increases. More importantly, the Gibbs free energy barrier has a strong linear correlation with the electrostatic energy of the chalcogen bond in the catalyst‐substrate complex. Furthermore, the catalytic reactions include the endo pathway and exo pathway. The C−H⋅⋅⋅π interaction between the substituent of the ethyl vinyl ether and the aryl ring of the N‐benzylideneaniline contributes to the endo‐selectivity of the reaction. This research contributes to a deeper understanding of chalcogen bond catalysis, providing insights for designing chalcogen bond catalysts with high performance.
Hydrated Formic Acid Clusters and their Interaction with Electrons
Authors: Li Kevin , Ďurana Jozef , Kocábková Barbora , Pysanenko Andrij , Yan Yihui , Ončák Milan , Fárník Michal , Lengyel Jozef 
Published: February 2024

AbstractWe investigate ion formation in hydrated formic acid (FA) clusters upon collision with electrons of variable energy, focusing on electron ionization at 70 eV (EI) and low‐energy (1.5–15 eV) electron attachment (EA). To uncover details about the composition of neutral clusters, we aim to elucidate the ion formation processes in FAM ⋅ WN clusters initiated by interaction with electrons and determine the extent of cluster fragmentation. EI predominantly produces protonated [FAm+H]+ ions, and in FA‐rich clusters, the stable ring structures surrounding H3O+ ions are formed. In contrast, EA leads to a competition between the formation of intact [FAm ⋅ Wn]− and dissociated [FAm ⋅ Wn−H]− fragment ions, influenced by the cluster size, level of hydration, and electron energy. Our findings reveal a predisposition of low‐energy EA towards forming [FAm ⋅ Wn]−, while higher electron energies tend to favor the formation of [FAm ⋅ Wn−H]− due to intracluster ion‐molecule reactions. The comparison of positive and negative ion spectra suggests that the mass spectra of FA‐rich clusters may indicate their actual size and composition. On the other hand, the more weakly bound water evaporation from the clusters depends strongly on the ionization. Thus, for the hydrated clusters, the neutral cluster size can hardly be estimated from the mass spectra.
Selective direct oxidation of 1‐butanol into acetal using hydrogen peroxide and Cs5MPW11(H2O)O39 (M=Fe, Co, Cu) catalysts
Authors: Lachquer Farah , Oulmekki Abdallah , Toyir Jamil 
Published: February 2024

AbstractDirect catalytic oxidation of alcohols to acetals in one step process is very attractive, because the two steps process leads firstly to aldehydes, which are unstable species serving as reactive intermediates to generate several by‐products reducing process efficiency and selectivity. In this work, a new selective catalytic acetalization of 1‐butanol into 1‐1‐dibutoxybutane acetal using H2O2 in one step process is investigated using Keggin‐type polyoxometalates catalysts. The materials developed consisted of new lacunary phophotungstate salts Cs5MPW11(H2O)O39 (M=Fe, Co and Cu) which were prepared by inorganic solution condensation method and characterized using XRD, IR, SEM and EDX analysis to verify their structure, surface morphology and chemical composition. Cs5CuPW11(H2O)O39 catalyst allowed the highest performance for the oxidation of 1‐butanol at 60 °C using H2O2 excess with a yield approaching 92 % and a turnover number of 784. Such activity is related to a bifunctional behavior of the catalyst as superacid and redox operating system and the synergistic effect created between the [PW11O39]7− Keggin framework, Cs+ and Cu2+.
A Mouse Model for Eosinophilic Esophagitis (EoE)
Authors: Dsilva Anish , Avlas Shmulik , Rhone Natalie , Itan Michal , Munitz Ariel 
Published: February 2024

AbstractEosinophilic esophagitis (EoE) is an emerging chronic T helper type 2 (Th2)‐associated, allergic, and immune‐mediated disease, characterized histologically by eosinophil‐predominant mucosal inflammation and clinically by esophageal dysfunction. Over the past years, the prevalence of EoE has dramatically increased globally. Until recently, most studies of EoE focused on using human biopsies, which are also used for diagnostic purposes, or esophageal epithelial cell lines, which led to major advances in the understanding of EoE. Despite this, a robust mouse model that mimics human disease is still crucial for both understanding disease pathogenesis and as a preclinical model for testing future therapeutics. Herein, we describe a highly reproducible and robust model of EoE that can be performed using wild‐type mice by ear sensitization with oxazolone (OXA) followed by intraesophageal challenges. Experimental EoE elicited by OXA mimics the main histopathological features of human EoE, including intraepithelial eosinophilia, epithelial and lamina propria thickening, basal cell hyperplasia, and fibrosis. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC.Basic Protocol: Induction of EoE in mice using oxazoloneSupport Protocol 1: Preparing the mouse esophagus for histological analysisSupport Protocol 2: Assessment of epithelial and lamina propria thickness using H&E stainingSupport Protocol 3: Assessment of eosinophilic infiltration using anti‐MBP and basal cell proliferation using anti‐Ki‐67 stainingSupport Protocol 4: Flow cytometry of mouse esophageal samplesSupport Protocol 5: ELISA on protein lysates of esophageal samples
Covalent Organic Frameworks for Water Harvesting from Air
Authors: Wen Fuxiang , Huang Ning 
Published: February 2024

AbstractDespite approximately 70 % of the earth being covered by water, water shortage has emerged as an urgent social challenge. Sorbent‐based atmospheric water harvesting stands out as a potent approach to alleviate the situation, particularly in arid regions. This method requires adsorbents with ample working capacity, rapid kinetics, low energy costs, and long‐term stability under operating conditions. Covalent organic frameworks (COFs) are a novel class of crystalline porous materials and offer distinct advantages due to their high specific surface area, structural diversity, and robustness. These properties enable the rational design and customization of their water‐harvesting capabilities. Herein, the basic concepts about the water sorption process within COFs, including the parameters that qualitatively or quantitatively describe their water isotherms and the mechanism are summarized. Then, the recent methods used to prepare COFs‐based water harvesters are reviewed, emphasizing the structural diversity of COFs and presenting the common empirical understandings of these endeavors. Finally, challenges and research concepts are proposed to help develop next‐generation COFs‐based water harvesters.
Half‐bridge secondary series resonant converter control for full voltage range
Authors: Kong Jiayi , Sun Rui , Xu Mingjin , Liu Xiaoqing 
Published: February 2024

SummaryThis paper proposes a full‐range regulation method for half‐bridge secondary series resonant converter. With the proposed method, the resonant converter can achieve full‐range regulation within a narrow frequency range regardless of the load level. Besides, the converter can be used for the battery charger systems and programmable power supply systems. The primary‐side transistors and the secondary‐side diodes are zero‐voltage switching turned on and zero‐current switching turned off, respectively. In‐depth analysis reveals the characteristics, that is, operation principle, voltage conversion ratio, component stresses, and ZVS condition of the half‐bridge secondary series resonant converter with the proposed method. Besides, the performance comparisons among the different methods are conducted to present the merits of the proposed method. Further, the performance comparisons between the half‐bridge secondary series resonant converter and primary series resonant converter with the proposed method are executed to show their superiority with different turns ratio range of the transformer, respectively. When the turns ratio is larger than 0.5 and smaller than 1, the performance of the half‐bridge primary series resonant converter is better; when the turns ratio is equal to 1, the two configurations feature the same performance; while when the turns ratio is larger than 1, the half‐bridge secondary series resonant converter is preferable. The experimental results validate the theoretical analysis.
Identifying squalene epoxidase as a metabolic vulnerability in high‐risk osteosarcoma using an artificial intelligence‐derived prognostic index
Authors: Wang Yongjie , Ma Xiaolong , Xu Enjie , Huang Zhen , Yang Chen , Zhu Kunpeng , Dong Yang , Zhang Chunlin 
Published: February 2024

AbstractBackgroundOsteosarcoma (OSA) presents a clinical challenge and has a low 5‐year survival rate. Currently, the lack of advanced stratification models makes personalized therapy difficult. This study aims to identify novel biomarkers to stratify high‐risk OSA patients and guide treatment.MethodsWe combined 10 machine‐learning algorithms into 101 combinations, from which the optimal model was established for predicting overall survival based on transcriptomic profiles for 254 samples. Alterations in transcriptomic, genomic and epigenomic landscapes were assessed to elucidate mechanisms driving poor prognosis. Single‐cell RNA sequencing (scRNA‐seq) unveiled genes overexpressed in OSA cells as potential therapeutic targets, one of which was validated via tissue staining, knockdown and pharmacological inhibition. We characterized changes in multiple phenotypes, including proliferation, colony formation, migration, invasion, apoptosis, chemosensitivity and in vivo tumourigenicity. RNA‐seq and Western blotting elucidated the impact of squalene epoxidase (SQLE) suppression on signalling pathways.ResultsThe artificial intelligence‐derived prognostic index (AIDPI), generated by our model, was an independent prognostic biomarker, outperforming clinicopathological factors and previously published signatures. Incorporating the AIDPI with clinical factors into a nomogram improved predictive accuracy. For user convenience, both the model and nomogram are accessible online. Patients in the high‐AIDPI group exhibited chemoresistance, coupled with overexpression of MYC and SQLE, increased mTORC1 signalling, disrupted PI3K–Akt signalling, and diminished immune infiltration. ScRNA‐seq revealed high expression of MYC and SQLE in OSA cells. Elevated SQLE expression correlated with chemoresistance and worse outcomes in OSA patients. Therapeutically, silencing SQLE suppressed OSA malignancy and enhanced chemosensitivity, mediated by cholesterol depletion and suppression of the FAK/PI3K/Akt/mTOR pathway. Furthermore, the SQLE‐specific inhibitor FR194738 demonstrated anti‐OSA effects in vivo and exhibited synergistic effects with chemotherapeutic agents.ConclusionsAIDPI is a robust biomarker for identifying the high‐risk subset of OSA patients. The SQLE protein emerges as a metabolic vulnerability in these patients, providing a target with translational potential.
Linking optical data and nitrates in the Lower Mississippi River to enable satellite‐based monitoring of nutrient reduction goals
Authors: Tufillaro Nicholas , Piazza Bryan P. , Reddy Sheila , Baustian Joseph , Sousa Dan , Grötsch Philipp , Lalović Ivan , De Moitié Sara , Zurita Omar 
Published: February 2024

AbstractHypoxic zones and associated nitrate pollution from farms, cities and industrial facilities is driving declines in water quality that affect ecosystems, economies and human health in major rivers and coastal areas worldwide. In the Mississippi River, the United States Environmental Protection Agency set a goal of reducing nitrogen loading 20% by 2025, but estimating progress towards this goal is difficult because data from in‐stream gauges and laboratory samples are too sparse. Satellites have the potential to provide sufficient data across the Mississippi River, if a key methodological challenge can be overcome. Satellites provide data from visible light, but nitrates are only observable with ultraviolet light. We address this methodological challenge by using a two‐step surrogate modelling procedure to link optical data and nitrates in the Lower Mississippi River. First, we correlate in situ nitrate measurements to common water quality parameters, particularly turbidity and chlorophyll, using data from water sensors installed at Baton Rouge, Louisiana, USA, and a long‐term dataset from Louisiana State University. Second, we correlate these water quality data to satellite estimates of water quality parameters. We found a correlation between these water quality parameters and nitrate concentrations, as indicated by a coefficient of determination, when the relationship was viewed in nonlinear parameter space. The spatial extent of the correlation was tested with an upstream nitrate sensor 140 km north of the estimation location. These results provide proof of concept that we can develop models that use satellite data to provide large‐scale monitoring of nitrates across the Mississippi River Basin and other impaired rivers, globally.
Mechanistic Insights of the Ir‐bipyridonate Catalyzed Aqueous Methanol Dehydrogenation and Transfer Dehydrogenation to Acetophenone: Experimental and DFT Study
Authors: Garg Nidhi , Poli Rinaldo , Sundararaju Basker 
Published: February 2024

AbstractThe mechanisms of the Cp*IrIII(bpyOO)‐catalyzed (bpyOO=bidentate (NN) doubly deprotonated 2,2′‐bipyridine‐6,6′‐diol) acceptorless methanol dehydrogenation and acetophenone transfer hydrogenation by methanol under basic conditions have been explored by the combination of 1H NMR, kinetics, and DFT computational studies. During dehydrogenation of methanol and of its dehydrogenated derivatives, the presence of two iridium hydride species (anionic [Cp*Ir(bpyOO)H]−, C* and neutral [Cp*Ir(bpyOOH)H], D*), which interconvert depending on pH, was detected. The DFT studies on a Cp model system highlighted three interrelated catalytic cycles of methanol, formaldehyde and formic acid dehydrogenation, all leading to the same hydride intermediates C and D. The dehydrogenation of methanol prefers a direct β‐hydride transfer pathway from the methoxide ion to Ir, rather than the classical β‐hydride elimination pathway from a coordinated methoxide ligand, but an alternative bifunctional H+/H− transfer with involvement of a ligand O atom may become competitive at lower pH. The transfer hydrogenation of acetophenone using methanol as hydrogen source features species C* as resting state, with the acetophenone reduction being rate‐determining and following the reverse pathway of methanol oxidation, with a first‐order acetophenone decay and a kinetic isotope effect of 2.36±0.09.
Trifluoromethylsulfinylation Reaction of Activated Arenes and Indoles with Trifluoromethanesulfinyl Chloride
Authors: Zhong Tian‐Cheng , Jiang Min , Liu Jin‐Tao 
Published: February 2024

AbstractThe trifluoromethylsulfinylation reaction of activated arenes with trifluoromethanesulfinyl chloride (CF3SOCl) in the presence of Lewis acid was achieved under mild and solvent‐free conditions. A series of aryl trifluoromethyl sulfoxides were obtained in moderate to high yields. The protocol could be extended to the perfluoroalkylsulfinylation of activated arenes, as well as the trifluoromethylsulfinylation of indoles without additive.
From single‐cell cloning to high‐yield influenza virus production – implementing advanced technologies in vaccine process development
Authors: Zinnecker Tilia , Badri Najd , Araujo Diogo , Thiele Kristin , Reichl Udo , Genzel Yvonne 
Published: February 2024

AbstractInnovations in viral vaccine manufacturing are crucial for pandemic preparedness and to meet ever‐rising global demands. For influenza, however, production still mainly relies on technologies established decades ago. Although modern production shifts from egg‐based towards cell culture technologies, the full potential has not yet been fully exploited. Here, we evaluate whether implementation of state‐of‐the‐art technologies for cell culture‐based recombinant protein production are capable to challenge outdated approaches in viral vaccine process development. For this, a fully automated single‐cell cloning strategy was established to generate monoclonal suspension Madin‐Darby canine kidney (MDCK) cells. Among selected cell clones, we could observe distinct metabolic and growth characteristics, with C59 reaching a maximum viable cell concentration of 17.3 × 106 cells/mL and low doubling times in batch mode. Screening for virus production using a panel of human vaccine‐relevant influenza A and B viruses in an ambr15 system revealed high titers with yields competing or even outperforming available MDCK cell lines. With C113, we achieved cell‐specific virus yields of up to 25,000 virions/cell, making this cell clone highly attractive for vaccine production. Finally, we confirmed process performance at a 50‐fold higher working volume. In summary, we present a scalable and powerful approach for accelerated development of high‐yield influenza virus production in chemically defined medium starting from a single cell.
Oxygen‐carrying semiconducting polymer nanoprodrugs induce sono‐pyroptosis for deep‐tissue tumor treatment
Authors: Wang Fengshuo , Fan Yongliang , Liu Yue , Lou Xiangxin , Sutrisno Linawati , Peng Shaojun , Li Jingchao 
Published: February 2024

AbstractSonodynamic therapy (SDT) has been explored for cancer therapy, especially for deep tumors due to its low tissue penetration restriction. The therapeutic efficacy of SDT is limited due to the complicated tumor microenvironment. This study reports the construction of oxygen‐carrying semiconducting polymer nanoprodrugs (OSPNpro) for deep tumor treatment via combining amplified SDT with pyroptosis. An oxygen carrier perfluorohexane, sonodynamic semiconducting polymer as the sonosensitizer, and reactive oxygen species (ROS)‐responsive prodrug are co‐loaded into a nanoparticle system, leading to the formation of these polymer nanoprodrugs. Such OSPNpro show an effective accumulation in tumor tissues after systemic administration, in which they deliver oxygen to relieve tumor hypoxia microenvironment and thus mediate amplified SDT via producing ROS under ultrasound (US) irradiation, even when the tumors are covered with a 2‐cm chicken breast tissue. In addition, the ROS‐responsive prodrugs are activated by the generated ROS to trigger pyroptosis of tumor cells. Such a sono‐pyroptosis induces a strong antitumor immunity with obviously higher level infiltrations of effector immune cells into tumors. Therefore, OSPNpro‐based combinational therapy can greatly inhibit the growth of 2‐cm chicken breast tissue‐covered deep tumors and suppress tumor metastasis. This study offers a prodrug nanoplatform for treatment of deep tumor via sono‐pyroptosis strategy.
Forecasting the high‐frequency volatility based on the LSTM‐HIT model
Authors: Liu Guangying , Zhuang Ziyan , Wang Min 
Published: February 2024

AbstractVolatility forecasting from high‐frequency data plays a crucial role in many financial fields, such as risk management, option pricing, and portfolio management. Many existing statistical models could better describe and forecast the characteristics of volatility, whereas they do not simultaneously account for the long‐term memory of volatility, the nonlinear characteristics of high‐frequency data, and technical index information during the modeling phase. The purpose of this paper is to use the prediction advantage of deep learning long short‐term memory (LSTM) model to predict the volatility fusing three classes of information, that is, high frequency realized volatility (H), technical indicators (I), and the parameters of generalized autoregression conditional heteroskedasticity(GARCH), heterogeneous autoregressive (HAR), and c, resulting in a novel LSTM‐HIT model to forecast realized volatility. We employ the extreme value theory (EVT) of a semiparametric method to estimate the quantile of standardized return and construct the LSTM‐HIT‐EVT model to forecast the value at risk (VaR). Empirical results show that the LSTM‐HIT model provides the most accurate volatility forecast among the various considered models and that the LSTM‐HIT‐EVT model yields forecasts more accurate than other VaR models.