bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transforming Hetera‐Buckybowls into Chiral Conjugated Polycycles Incorporating Epoxycyclooctadiene: a Two‐Step Approach
Authors: Wang Xue , Hua Xinqiang , Zhang Haomin , Wu Lingxi , Yuan Chengshan , Liu Zitong , Zhang Hao‐Li , Shao Xiangfeng 
Published: October 2023

AbstractChiral π‐conjugated polycycles have garnered increasing attention due to versatile applications in optoelectronic materials and biological sciences. In this study, we report the synthesis of chiral π‐conjugated polycycles incorporating a chiral epoxycyclooctadiene moiety. Our synthetic strategy capitalizes on the novel reactions of hetera‐buckybowl triselenasumanene (TSS) and is achieved in two‐step manner. Firstly, the TSS is regio‐selectively transformed into its ortho‐quinone form. Subsequently, the nucleophilic addition reactions of TSS ortho‐quinone by phenylethynides are metal ion‐dependent. When utilizing (phenylethynyl)magnesium bromide as the nucleophile, two phenylethynyls are furnished onto the edged benzene ring of TSS. When the nucleophile is (phenylethynyl)lithium, a cascade of nucleophilic addition, intermolecular electron‐transfer, ring‐opening, and tetradehydro‐Diels–Alder (TDDA) reactions occur sequentially in one‐pot, ultimately affording chiral π‐conjugated polycycles featuring the epoxycyclooctadiene moiety as an integral part of their backbones. This work represents a step forward in the synthesis of chiral π‐conjugated polycycles using TSS as synthon.
Electrochemical Synthesis of Gold‐N‐Heterocyclic Carbene Complexes**
Authors: Nicholls Thomas P. , Jia Zhongfan , Chalker Justin M. 
Published: October 2023

AbstractAn electrochemical synthesis of gold(I)‐N‐heterocyclic carbene (Au‐NHC) complexes has been developed. The electrochemical methodology uses only imidazolium salts, gold metal electrodes, and electricity to produce these complexes with hydrogen gas as the only by‐product. This high‐yielding and operationally simple procedure has been used to produce eight mononuclear and three dinuclear Au‐NHC complexes. The electrochemical procedure facilitates a clean reaction with no by‐products. As such, Au‐NHC complexes can be directly transferred to catalytic reactions without work‐up or purification. The Au‐NHC complexes were produced on‐demand and tested as catalysts in a vinylcyclopropanation reaction. All mononuclear Au‐NHC complexes performed similarly to or better than the isolated complexes.
Modifying the Catalytic Activity of Lipopeptide Assemblies with Nucleobases
Authors: Vela‐Gallego Sonia , Lewandowski Bartosz , Möhler Jasper , Puente Alonso , Gil‐Cantero David , Wennemers Helma , de la Escosura Andrés 
Published: October 2023

AbstractBiohybrid catalysts that operate in aqueous media are intriguing for systems chemistry. In this paper, we investigate whether control over the self‐assembly of biohybrid catalysts can tune their properties. As a model, we use the catalytic activity of functional hybrid molecules consisting of a catalytic H‐dPro‐Pro‐Glu tripeptide, derivatized with fatty acid and nucleobase moieties. This combination of simple biological components merged the catalytic properties of the peptide with the self‐assembly of the lipid, and the structural ordering of the nucleobases. The biomolecule hybrids self‐assemble in aqueous media into fibrillar assemblies and catalyze the reaction between butanal and nitrostyrene. The interactions between the nucleobases enhanced the order of the supramolecular structures and affected their catalytic activity and stereoselectivity. The results point to the significant control and ordering that nucleobases can provide in the self‐assembly of biologically inspired supramolecular catalysts.
Separation of the enantiomers of coumarinic anticoagulant drugs by capillary electrophoresis using maltodextrins as chiral modifiers
Authors: D'Hulst Annick , Verbeke Norbert 
Published: October 2023

AbstractThe separation and quantitation of coumarinic anticoagulant drug enantiomers were achieved by direct chiral capillary electrophoresis using complex maltooligosaccharide mixtures as stereoselective electrolyte modifiers. Chiral separations were characterized by a high selectivity and efficiency, enabling enantiomeric excess determinations. In addition, preliminary results indicate the applicability of the method for the determination of individual enantiomers in biological samples. So the method can be used to perform stereoselective pharmacokinetic studies. © 1994 Wiley‐Liss, Inc.
Competition between Loss of H2 versus H+H in the Fragmentation of the Fluorene Cation
Authors: Désesquelles Pierre , Domin Dominik , Xu Lejin , Van‐Oanh Nguyen‐Thi 
Published: October 2023

AbstractThe fluorene cation is a frequently studied molecule in the context of fragmentation experiments. This is because of its potential role in interstellar chemistry, notably as a precursor of PAH cages. In this paper, we analyze H, H+, H2 and
losses from the fluorene cation using the SMF (Statistical Molecular Fragmentation) model. We calculate the probabilities of all the 534 possible fragmentation channels as a function of the excitation energy, up to the loss of three hydrogens. Four different types of hydrogen atom pairings (from the same carbon, from the same ring, from different rings and across‐the‐bay) have been tested in order to determine which types contribute to the actual production of hydrogen molecules. The simulated breakdown curves are in very good agreement with different experimental results when same ring pairing is taken into account. It was possible to deduce from the model the locations of the emitted H, H+, H2 and
species.
Kinetics of the Temperature‐Dependent eaq− and ⋅OH Radical Reactions with Cr(III) Ions in Aqueous Solutions
Authors: Conrad Jacy K. , Lisouskaya Aliaksandra , Mezyk Stephen P. , Bartels David M. 
Published: October 2023

AbstractThe reactivity of chromium(III) species with the major oxidizing and reducing radiolysis products of water was investigated in aqueous solutions at temperatures up to 150 °C. The reaction between the hydrated electron (eaq−) and Cr(III) species showed a positive temperature dependence over this temperature range. The reaction was also studied in pH 2.5 and 3.5 solutions for the first time. This work also studied the reaction between acidic Cr(III) species and the hydroxyl radical (⋅OH). It was found that Cr3+ did not react significantly with the ⋅OH radical, but the first hydrolysis species, Cr(OH)2+, did with a rate coefficient of k= (7.2±0.3)×108 M−1 s−1 at 25 °C. The oxidation of Cr(OH)2+ by the ⋅OH radical formed an absorbing product species that ultimately oxidized to give Cr(VI). These newly measured reaction rates allow for the development of improved models of aqueous chromium speciation for the effective remediation of liquid high‐level nuclear waste via vitrification processes.
Partial Methane Oxidation to Methanol on Ru‐Porphyrins – on the Role of Non‐Innocent Ligands and Spin Crossover
Authors: Kizior Beata , Jezierska Aneta , Szyja Bartłomiej M. 
Published: October 2023

AbstractThe partial oxidation reaction of CH4 led to the formation of CH3OH in the presence of Ru‐porphyrin oxo complexes (denoted as POR, POR‐O and POR‐OH where in the case of the last two, oxygen atom and the OH group were attached to the active site, respectively), in which Ru was present on different oxidation states. The simulations were performed based on Density Functional Theory (DFT) with extended geometric and electronic structure analyses of each reaction step. Moreover, the reaction pathways were investigated in different spin states. The Spin Crossover (SCO) phenomenon was found to play an important role in the kinetics of the reaction in the presence of POR and POR‐O. Harmonic Oscillator Model of Aromaticity (HOMA) index was applied for different spin states to estimate the aromaticity changes of the pyrrole rings in the Ru‐porphyrin complexes. In order to characterize the nature of bonding, the Natural Bond Orbitals (NBO) analysis including the Wiberg Bond Index (WBI) and Natural Population Analysis (NPA) was carried out. Finally, the Non‐Covalent Interactions (NCI) index was employed to gain insight into interactions between the components of the reaction. It was found that the non‐covalent interactions cannot be neglected in the studied reaction paths.
Catalytic Behavior of K‐doped Fe/MgO Catalysts for Ammonia Synthesis Under Mild Reaction Conditions
Authors: Era Kohei , Sato Katsutoshi , Miyahara Shin‐ichiro , Naito Takahiro , De Silva Kanishka , Akrami Saeid , Yamada Hiroshi , Toriyama Takaaki , Yamamoto Tomokazu , Murakami Yasukazu , Aika Ken‐ichi , Inazu Koji , Nagaoka Katsutoshi 
Published: October 2023

AbstractAn important part of realizing a carbon‐neutral society using ammonia will be the development of an inexpensive yet efficient catalyst for ammonia synthesis under mild reaction conditions (<400 °C, <10 MPa). Here, we report Fe/K(3)/MgO, fabricated via an impregnation method, as a highly active catalyst for ammonia synthesis under mild reaction conditions (350 °C, 1.0 MPa). At the mentioned conditions, the activity of Fe/K(3)/MgO (17.5 mmol h−1 gcat−1) was greater than that of a commercial fused iron catalyst (8.6 mmol h−1 gcat−1) currently used in the Haber‐Bosch process. K doping was found to increase the ratio of Fe0 on the surface and turnover frequency of Fe in our Fe/K(3)/MgO catalyst. In addition, increasing the pressure to 3.0 MPa at the same temperature led to a significant improvement of the ammonia synthesis rate to 29.6 mmol h−1 gcat−1, which was higher than that of two more expensive, benchmark Ru‐based catalysts, which are also potential alternative catalysts. A kinetics analysis revealed that the addition of K enhanced the ammonia synthesis activity at ≥300 °C by changing the main adsorbed species from NH to N which can accelerate dissociative adsorption of nitrogen as the rate limiting step in ammonia synthesis.
N6‐methyladenosine‐modified circSTX6 promotes hepatocellular carcinoma progression by regulating the HNRNPD/ATF3 axis and encoding a 144 amino acid polypeptide
Authors: Lu Jiahua , Ru Junnan , Chen Yunhao , Ling Zhenan , Liu Hanqing , Ding Bo , Jiang Yifan , Ma Jun , Zhang Deguo , Ge Jiangzhen , Li Yu , Sun Fei , Chen Diyu , Zheng Shusen , Wu Jian 
Published: October 2023

AbstractBackgroundCircular RNAs (circRNAs) play a significant role in the initiation and progression of various cancers, including hepatocellular carcinoma (HCC). Circular syntaxin 6 (circSTX6, also known as hsa_circ_0007905) has been identified as a microRNA (miRNA) sponge in pancreatic adenocarcinoma. However, its full range of functions in terms of protein scaffold and translation remain largely unexplored in the context of HCC.MethodsThe expression of circSTX6 and its encoded protein was examined in HCC tumour tissues. N6‐methyladenosine (m6A) on circSTX6 was verified and quantified by methylated RNA immunoprecipitation (Me‐RIP), RIP and dual luciferase reporter assays. The biological functions of circSTX6 and its encoded protein in HCC were clarified by in vitro and in vivo experiments. Mechanistically, the interaction between circSTX6 and heterogeneous nuclear ribonucleoprotein D (HNRNPD) was investigated by RNA pull‐down, RIP and fluorescence in situ hybridization (FISH)/IF. The regulatory effects of circSTX6 and HNRNPD on activating transcription factor 3 (ATF3) mRNA were determined by mRNA stability and RIP assays. Furthermore, the presence of circSTX6‐encoded protein was verified by mass spectrometry.ResultsCircSTX6 and its encoded 144 amino acid polypeptide, circSTX6‐144aa, were highly expressed in HCC tumour tissues and served as independent risk factors for overall survival in HCC patients. The expression of circSTX6 was regulated by METTL14 in an m6A‐dependent manner. Functionally, circSTX6 accelerated HCC proliferation and tumourigenicity and reinforced tumour metastasis in vitro and in vivo. Mechanistically, circSTX6 acted as a sponge for HNRNPD protein, facilitating its binding to ATF3 mRNA, consequently promoting ATF3 mRNA decay. Meanwhile, circSTX6‐144aa promoted HCC proliferation, migration and invasion independent of circSTX6 itself.ConclusionCollectively, our study reveals that m6A‐modified circSTX6 drives malignancy in HCC through the HNRNPD/ATF3 axis, while its encoded circSTX6‐144aa contributes to HCC progression independent of circSTX6. CirSTX6 and its encoded protein hold promise as potential biomarkers and therapeutic targets in HCC.
Combined effects of soil 3D spatial heterogeneity and biotic spatial heterogeneity (plant clumping) on ecosystem processes in grasslands
Authors: Vindušková O. , Deckmyn G. , Bortier M. , De Boeck H. J. , Liu Y. , Nijs I. 
Published: October 2023

AbstractSoil heterogeneity has been shown to enhance plant diversity, but its effect on grassland productivity is less clear. Even less is known about the effect of plant clumping (intraspecific aggregation) and its potential interaction with soil heterogeneity. The combined effects of soil 3D spatial heterogeneity and species clumping were experimentally studied in grassland mesocosms consisting of four grassland species. These species were planted in three patterns (i.e. completely mixed, clumped by 9 or 36 individuals of the same species) on soils with heterogeneous cells of alternating nutrient‐poor and rich soil differing in size from 0 (mixed soil) to 12, 24, and 48 cm (complete poor or rich mesocosm). Moderate soil cell sizes (12–24 cm) consistently increased whole‐mesocosm aboveground productivity by more than 20%, which mainly originated from the increased growth of the plants growing on the poor soil cells. In contrast, total mesocosm productivity was not affected by species clumping although there were some species‐specific effects, both of clumping and of the interaction of clumping with soil heterogeneity. Our results show that intermediate soil heterogeneity promotes productivity. Clumping can improve the growth of inferior species, thus promoting coexistence, without affecting overall productivity. We found no interaction effect of clumping and soil heterogeneity on productivity at the community level and some minor species‐specific effects.
Multidimensional beta‐diversity across local and regional scales in a Chinese subtropical forest: The role of forest structure
Authors: Yao Zhiliang , Yang Xin , Wang Bin , Shao Xiaona , Wen Handong , Deng Yun , Zhang Zhiming , Cao Min , Lin Luxiang 
Published: October 2023

AbstractBeta‐diversity, or the spatio‐temporal variation in community composition, can be partitioned into turnover and nestedness components in a multidimensional framework. Forest structure, including comprehensive characteristics of vertical and horizontal complexity, strongly affects species composition and its spatial variation. However, the effects of forest structure on beta‐diversity patterns in multidimensional and multiple‐scale contexts are poorly understood. Here, we assessed beta‐diversity at local (a 20‐ha forest dynamics plot) and regional (a plot network composed of 19 1‐ha plots) scales in a Chinese subtropical evergreen broad‐leaved forest. We then evaluated the relative importance of forest structure, topography, and spatial structure on beta‐diversity and its turnover and nestedness components in taxonomic, functional, and phylogenetic dimensions at local and regional scales. We derived forest structural parameters from both unmanned aerial vehicle light detection and ranging (UAV LiDAR) data and plot inventory data. Turnover component dominated total beta‐diversity for all dimensions at the two scales. With the exception of some components (taxonomic and functional turnover at the local scale; functional nestedness at the regional scale), environmental factors (i.e., topography and forest structure) contributed more than pure spatial variation. Explanations of forest structure for beta‐diversity and its component patterns at the local scale were higher than those at the regional scale. The joint effects of spatial structure and forest structure influenced component patterns in all dimensions (except for functional turnover) to some extent at the local scale, while pure forest structure influenced taxonomic and phylogenetic nestedness patterns to some extent at the regional scale. Our results highlight the importance and scale dependence of forest structure in shaping multidimensional beta‐diversity and its component patterns. Clearly, further studies need to link forest structure directly to ecological processes (e.g., asymmetric light competition and disturbance dynamics) and explore its roles in biodiversity maintenance.
Qiliqiangxin: A multifaceted holistic treatment for heart failure or a pharmacological probe for the identification of cardioprotective mechanisms?
Authors: Packer Milton 
Published: October 2023

The active ingredients in many traditional Chinese medicines are isoprene oligomers with a diterpenoid or triterpenoid structure, which exert cardiovascular effects by signalling through nutrient surplus and nutrient deprivation pathways. Qiliqiangxin (QLQX) is a commercial formulation of 11 different plant ingredients, whose active compounds include astragaloside IV, tanshione IIA, ginsenosides (Rb1, Rg1 and Re) and periplocymarin. In the QUEST trial, QLQX reduced the combined risk of cardiovascular death or heart failure hospitalization (hazard ratio 0.78, 95% confidence interval 0.68–0.90), based on 859 events in 3119 patients over a median of 18.2 months; the benefits were seen in patients taking foundational drugs except for sodium–glucose cotransporter 2 (SGLT2) inhibitors. Numerous experimental studies of QLQX in diverse cardiac injuries have yielded highly consistent findings. In marked abrupt cardiac injury, QLQX mitigated cardiac injury by upregulating nutrient surplus signalling through the PI3K/Akt/mTOR/HIF‐1α/NRF2 pathway; the benefits of QLQX were abrogated by suppression of PI3K, Akt, mTOR, HIF‐1α or NRF2. In contrast, in prolonged measured cardiac stress (as in chronic heart failure), QLQX ameliorated oxidative stress, maladaptive hypertrophy, cardiomyocyte apoptosis, and proinflammatory and profibrotic pathways, while enhancing mitochondrial health and promoting glucose and fatty acid oxidation and ATP production. These effects are achieved by an action of QLQX to upregulate nutrient deprivation signalling through SIRT1/AMPK/PGC‐1α and enhanced autophagic flux. In particular, QLQX appears to enhance the interaction of PGC‐1α with PPARα, possibly by direct binding to RXRα; silencing of SIRT1, PGC‐1α and RXRα abrogated the favourable effects of QLQX in the heart. Since PGC‐1α/RXRα is also a downstream effector of Akt/mTOR signalling, the actions of QLQX on PGC‐1α/RXRα may explain its favourable effects in both acute and chronic stress. Intriguingly, the individual ingredients in QLQX – astragaloside IV, ginsenosides, and tanshione IIA – share QLQX's effects on PGC‐1α/RXRα/PPARα signalling. QXQL also contains periplocymarin, a cardiac glycoside that inhibits Na+‐K+‐ATPase. Taken collectively, these observations support a conceptual framework for understanding the mechanism of action for QLQX in heart failure. The high likelihood of overlap in the mechanism of action of QLQX and SGLT2 inhibitors requires additional experimental studies and clinical trials.
Epidemiology and clinical aspect of mushroom poisonings in South Sardinia: A 10‐year retrospective analysis (2011–2021)
Authors: La Rosa Laura , Corrias Serafina , Pintor Iginio , Cosentino Sofia 
Published: October 2023

AbstractMushroom poisoning is a severe problem of public health, however, information about its epidemiology and management is still limited. This is the first study focused on Sardinia that investigates data about mushroom poisoning describing epidemiology, clinical presentation, seasonality, and the most common involved species. In this retrospective study, we analyzed data recovered from the database of Mycological Inspectorates during a 10‐year period (2011–2021). Overall, 164 cases of mushroom poisoning have been identified, with significant peaks in autumn. The highest number of episodes of intoxication were recorded in Cagliari (64), followed by Carbonia (55) and Sanluri (45), although the annual distribution of cases among the provinces varied considerably in the study period. Thanks to the expertise of the Mycological Inspectorate service, the implicated species have been identified in 162 cases (98.78%); 81 cases were caused by toxic species, 60 by edible, and 45 by not edible species. Omphalotus olearius and Agaricus xanthodermus were the most represented toxic species (22% and 18%, respectively); Boletus aereus (18%) was the most frequent edible species, while Boletaceae were the prevalent not edible mushrooms. The data collected in South Sardinia over a period of 10‐years demonstrate how a correct and rapid recognition of mushroom poisoning is important to improve the prognosis of patients, however, there are still problems of lack of knowledge, on the part of the population, on the existence of the consultancy services. Because most illnesses from poisonous mushroom ingestion are preventable, increased public awareness about the potential dangers of mushroom poisoning is mandatory.
Low intracellular water and incident cognitive impairment in chronic hemodialysis patients
Authors: Tian Maolu , Yuan Jing , Yu Fangfang , He Pinghong , Hu Shanshan , Zha Yan 
Published: October 2023

AbstractObjectiveTo explore the effect of intracellular water (ICW) evaluated by the bioelectrical Impedance Spectroscopy (BIS) on the risk of incident cognitive impairment (CI) in chronic hemodialysis (HD) patients.MethodsThree thousand three hundred eighty‐five patients were recruited and monitored prospectively for up to 3 years (the median follow‐up time, 2 years) in this observational cohort study. Mini‐Mental State Examination score (MMSE) was used to assess the global cognitive function. ICW was measured by body composition monitor based on BIS. Multiple Cox regression models, stratified analyses, and interactive analyses were conducted.ResultsDuring the follow‐up period, 1256 patients (37.1%) experienced incident CI. The incidence of CI was increased with decreasing quartiles of ICW (27.4%, 32.2%, 38.9%, and 50.1% for the fourth, third, second, and first quartiles, respectively). Decreased ICW was significantly associated with incident CI. The association remained statistically significant even after adjusting for age, sex, education, albumin, C‐reactive protein, residual renal function and various medical histories. The hazard ratios were 1.38 (1.17–1.64) and 1.28 (1.08–1.52) for ICW quartile 1 and quartile 2, respectively (reference, quartile 4). The association stably existed across subgroups, and the residual renal function had an interactive role in the association between ICW and incident CI (p = 0.014).ConclusionLow baseline ICW was an independent risk factor for CI in chronic HD patients. Our finding highlights the necessity of using BIS to measure body composition when assessing the risk of CI in HD patients.