bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solvent Attenuation of London Dispersion in Polycyclic Aromatic Stacking
Authors: Elmi Alex , Bąk Krzysztof M. , Cockroft Scott L. 
Published: July 2024

AbstractSolvent competition for London dispersion attenuates its energetic significance in molecular recognition processes. By varying both the stacked contact area and the solvent, here we experimentally deconvolute solvent attenuation using molecular balances. Experimental stacking energies (phenyl to pyrene) correlated strongly with calculations only when dispersion was considered. Such calculations favoured stacking by up to −27 kJ mol−1 in the gas phase, but it was weakly disfavoured in our solution‐phase experiments (+0.5 to +4.6 kJ mol−1). Nonetheless, the propensity for stacking increased with contact area and in solvents with lower bulk polarisabilities that compete less for dispersion. Experimental stacking energies per unit change in solvent accessible area ranged from −0.02 kJ mol−1 Å−2 in CS2, to −0.05 kJ mol−1 Å−2 in CD2Cl2, but were dwarfed by the calculated gas‐phase energy of −0.6 kJ mol−1 Å−2. The results underscore the challenge facing the exploitation of dispersion in solution. Solvent competition strongly but imperfectly cancels dispersion at molecular recognition interfaces, making the energetic benefits difficult to realise.
Insulator‐Transition‐Induced Degradation of Pyrochlore Ruthenates in Electrocatalytic Oxygen Evolution and Stabilization through Doping
Authors: Liu Tongtong , Guo Hengyu , Zhang Qingren , Fujishige Masatsugu , Endo Morinobu , Zhang Zhengping , Wang Feng 
Published: July 2024

AbstractRu‐based pyrochlores (e.g., Y2Ru2O7−δ) are promised to replace IrO2 in polymer electrolyte membrane (PEM) electrolyzers. It is significant to reveal the cliff attenuation on the oxygen evolution reaction (OER) performance of these pyrochlores. In this work, we monitor the structure changes and electrochemical behavior of Y2Ru2O7−δ over the OER process, and it is found that the reason of decisive OER inactivation is derived from an insulator transition occurred within Y2Ru2O7−δ due to its inner “perfecting” lattice induced by continuous atom rearrangement. Therefore, a stabilization strategy of the Ir‐substituted Y2Ru2O7−δ is proposed to alleviate this undesirable behavior. The double‐exchange interaction between Ru and Ir in [RuO6] and [IrO6] octahedra leads the charge redistribution with simultaneous spin configuration adjustment. The electronic state in newly formed octahedrons centered with Ru 4d3 (with the state of eg′↑↑a1g↑ eg0) and Ir 5d6 (eg′↑↓↑↓a1g↑↓ eg0) relieves the uneven electron distributions in [RuO6] orbital. The attenuated Jahn–Teller effect alleviates atom rearrangement, represented as the mitigation of insulator transition, surface reconstruction, and metal dissolution. As results, the Ir‐substituted Y2Ru2O7−δ presents the greatly improved OER stability and PEM durability. This study unveils the OER degradation mechanism and stabilization strategy for material design of Ru‐based OER catalysts for electrochemical applications.
Exploring the Complex Chemistry and Degradation of Ascorbic Acid in Aqueous Nanoparticle Synthesis
Authors: Roy Debashree , Johnson Hannah M. , Hurlock Matthew J. , Roy Kingshuk , Zhang Qiang , Moreau Liane M. 
Published: July 2024

AbstractAscorbic acid (AA) is the most widely used reductant for noble metal nanoparticle (NP) synthesis. Despite the synthetic relevance, its aqueous chemistry remains misunderstood, due in part to various assumptions about its reduction pathway which are insufficiently supported by experimental evidence. This study aims to provide an understanding of the complex chemistry associated with AA under aqueous conditions. We demonstrate that (i) AA undergoes appreciable degradation in alkaline solution on a timescale relevant to NP synthesis, (ii) contrary to popular belief, AA does not degrade into dehydroascorbic acid (DHA), nor is DHA the oxidized product of AA under noble metal NP synthetic conditions, (iii) DHA, which readily degrades under alkaline conditions, can also effectively reduce metal salt precursors to metal NPs, (iv) neither ascorbate nor dehydroascorbate act as surface capping agents post‐synthetically on the NPs (v) AA degradation time greatly affects the morphology and polydispersity of the resultant NP. Results from our mechanistic investigation enabled us to utilize purposefully‐aged reductants to achieve control over shape yield and monodispersity in the seed‐mediated synthesis of Au nanorods. Our findings have important implications for achieving monodispersed products in the many metal NP synthesis reactions that make use of AA as a reducing agent.
Synthesis of Alkene Atropisomers with Multiple Stereogenic Elements via Catalytic Asymmetric Rearrangement of 3‐Indolylmethanols
Authors: Wu Ping , Zhang Wen‐Tao , Yang Ji‐Xiang , Yu Xian‐Yang , Ni Shao‐Fei , Tan Wei , Shi Feng 
Published: July 2024

AbstractCatalytic enantioselective preparation of alkene atropisomers with multiple stereogenic elements and discovery of their applications have become significant but challenging issues in the scientific community due to the unique structures of this class of atropisomers. We herein report the first catalytic atroposelective preparation of cyclopentenyl[b]indoles, a new kind of alkene atropisomers, with stereogenic point and axial chirality via an unusual rearrangement reaction of 3‐indolylmethanols under asymmetric organocatalysis. Notably, this novel type of alkene atropisomers have promising applications in developing chiral ligands or organocatalysts, discovering antitumor drug candidates and fluorescence imaging materials. Moreover, the theoretical calculations have elucidated the possible reaction mechanism and the non‐covalent interactions to control the enantioselectivity. This approach offers a new synthetic strategy for alkene atropisomers with multiple stereogenic elements, and represents the first catalytic enantioselective rearrangement reaction of 3‐indolylmethanols, which will advance the chemistry of atropisomers and chiral indole chemistry.
Enzyme Machinery for Bacterial Glucoside Metabolism through a Conserved Non‐hydrolytic Pathway
Authors: Kastner Klara , Bitter Johannes , Pfeiffer Martin , Grininger Christoph , Oberdorfer Gustav , Pavkov‐Keller Tea , Weber Hansjörg , Nidetzky Bernd 
Published: July 2024

AbstractThe flexible acquisition of substrates from nutrient pools is critical for microbes to prevail in competitive environments. To acquire glucose from diverse glycoside and disaccharide substrates, many free‐living and symbiotic bacteria have developed, alongside hydrolysis, a non‐hydrolytic pathway comprised of four biochemical steps and conferred from a single glycoside utilization gene locus (GUL). Mechanistically, this pathway integrates within the framework of oxidation and reduction at the glucosyl/glucose C3, the eliminative cleavage of the glycosidic bond and the addition of water in two consecutive lyase‐catalyzed reactions. Here, based on study of enzymes from the phytopathogen Agrobacterium tumefaciens, we reveal a conserved Mn2+ metallocenter active site in both lyases and identify the structural requirements for specific catalysis to elimination of 3‐keto‐glucosides and water addition to the resulting 2‐hydroxy‐3‐keto‐glycal product, yielding 3‐keto‐glucose. Extending our search of GUL‐encoded putative lyases to the human gut commensal Bacteroides thetaiotaomicron, we discover a Ca2+ metallocenter active site in a putative glycoside hydrolase‐like protein and demonstrate its catalytic function in the eliminative cleavage of 3‐keto‐glucosides of opposite (α) anomeric configuration as preferred by the A. tumefaciens enzyme (β). Structural and biochemical comparisons reveal the molecular‐mechanistic origin of 3‐keto‐glucoside lyase stereo‐complementarity. Our findings identify a basic set of GUL‐encoded lyases for glucoside metabolism and assign physiological significance to GUL genetic diversity in the bacterial domain of life.
Gold‐Catalyzed Alkoxy‐Carbonylation of Aryl and Vinyl Iodides
Authors: Bhoyare Vivek W. , Bera Asish , Gandon Vincent , Patil Nitin T. 
Published: July 2024

AbstractHerein, for the first time, we disclose the gold‐catalyzed alkoxy‐carbonylation of aryl and vinyl iodides utilizing ligand‐enabled Au(I)/Au(III) redox catalysis. The present methodology is found to be general, efficient, employs mild reaction conditions and showcases a broad substrate scope even with structurally complex molecules. Density functional theory (DFT) calculations revealed mechanistic pathways distinct from those of conventional transition metal‐catalyzed carbonylation reactions.
Flexible mussel‐inspired hydrogel for transparent wearable strain sensors: Investigation of mechanical, physical properties, self‐healing, and electrical conductivity
Authors: Mirzaei Ghazaleh , Mirzaei Akbar , Javanshir Shahrzad 
Published: July 2024

AbstractNowadays, flexible hydrogels with electrical conductivity have become extremely helpful with broad application scenarios in electronic membranes in human–machine boundaries. However, a design approach to adjust and ameliorate conductivity, mechanical strength, transparency, self‐healing, and good adhesion remains a challenge. One of these strategies is mussels‐mimicking adhesive hydrogels, presenting strong adhesion. Here, we aim to meet the challenge by pursuing a mussel‐inspired design approach, which leads to the formation of a transparent, self‐healing, adhesive, and electrically conductive hydrogel from dopamine (DA), pyrrole (Py), acrylamide (AM), functionalized iron, and copper ions as an advanced electronic sensor. The transparent hydrogels were prepared using a sonication polymerization method. The results have shown that hydrogels containing copper or iron have conductivity (12 × 10−4 or 27 × 10−4 S/cm), mechanical strength (11.2 or 18.4 kPa), elongation at break (EB: 652.231% or 660.198%) and gauge factors (GF: 3.04679, 2.93513). Also, hydrogels can maintain their conductivity if they are twisted or stretched. Self‐healing behavior, swelling, and water‐induced shape memory effect (SME) due to hydrogen bonds and π–π interactions were observed. The behavior of this hydrogel as wearable sensors in integration with different body tissues such as finger, wrist, breathing, and frown was investigated. The obtained hydrogels showed high sensitivity in different areas of the body, fast response time in the strain range of 0%–%500, and high adhesion and transparency.
The thawing process in gentamicin and polyethylene glycol hydrogel: The impact of selected parameters on the calculation of activation energy using the methods of Belichmaer and Duswalt
Authors: Talik Przemysław , Lalik Krzysztof 
Published: July 2024

AbstractThe subject of the research conducted by differential scanning calorimetry (DSC) was hydrated mixtures of polyethylene glycol and gentamicin (GEN) in a 1:1 (w/w) ratio. In this way, a system with a particularly high ability to form hydrogen bonds was created. It was postulated that studying the effective activation energy (EA) of the thawing process of diverse hydrated polymer mixtures will indirectly allow for an attempt to assess the distribution of water molecules in the examined material in future studies. This article presents a detailed analysis of the impact of selected parameters on the calculation of EA using the Belichmaer and Duswalt methods. The research focused on assessing how the interpolation method affects the accuracy of results obtained from these techniques. The interpolation method was analyzed in terms of its ability to accurately replicate experimental data. By evaluating the impact of the number of points from the DSC curve used in linear interpolation, a standard deviation from the average value of EA was obtained, respectively: 2.4% for the Belichmaer method and 1.9% for the Duswalt method. The article also shows that by using both methods simultaneously, it is possible to detect the moment when additional endothermic and exothermic reaction activity becomes present in the reaction curve. This allowed for the avoidance of the depletion error. Computer modeling and simulations were used to compare the effectiveness of both techniques in various scenarios. The results showed that the choice of interpolation method and taking into account the depletion error significantly affect the accuracy of calculating EA. The computed activation energy via Duswalt method was EA = 363.32 kJ mol−1 with a standard deviation of 7.07 kJ mol−1 and using the Belichmaer method the EA was 364.81 kJ mol−1, with a standard deviation of 9.10 kJ mol−1.
Comparative study of pure and mixed phase sulfurized‐carbon black in battery cathodes for lithium sulfur batteries
Authors: Sahoo Surjit , Chatterjee Debayan , Majumder Subhasish Basu , Raihan Kh M Asif , LaCroix Brice , Das Suprem R. 
Published: July 2024

AbstractLithium‐sulfur battery (LSB) chemistry is regarded as one of the most promising contenders for powering next‐generation electronics, including electric vehicles. This is due to its high theoretical capacity, the use of inexpensive and environmentally friendly materials, and its alignment with climate‐smart manufacturing principles. Sulfur, the electroactive element in LSBs, undergoes lithiation to form a series of polysulfides, each contributing to the battery's energy density. However, this chemistry encounters several challenges, particularly concerning the stability of sulfur. Recent studies have shown that the presence of a full gamma phase of sulfur in an LSB cathode significantly enhances the capacity and overall cell performance. However, despite the advantages of cathodes with gamma sulfur, the characteristics of LSBs with mixed crystal phases of sulfur (alpha, beta, and gamma) have not been extensively studied. In this context, we developed a simple and cost‐effective synthesis method to produce both single‐phase (alpha) and mixed‐phase sulfur (primarily a mixture of alpha and gamma, with a trace of beta) and conducted their detailed physical and electrochemical characterization for use as electroactive cathode materials in LSBs. The cells fabricated using sulfur‐carbon black as the cathode delivered a specific capacity of approximately 640 mAh/g at a current density of 275 mA/g, demonstrating excellent cyclic stability over 50 cycles with a capacity retention of around 97%. This performance is superior to that of the sulfur‐baked carbon black composite cathode, which achieved 440 mAh/g at the same current density.
Mid‐Infrared Optoelectronic Waveguide Devices with 2D Materials
Authors: Qi Liqiang , Xu Tianping , Xing Zhengkun , Chen Si , Zhang Zunyue , Liu Tiegen , Cheng Zhenzhou 
Published: July 2024

AbstractMid‐infrared (Mid‐IR) integrated optics has tremendous applications in spectroscopic sensing, imaging, and ranging. Compared with visible light and near‐IR wavelengths, the study of mid‐IR photonic integrated devices is limited due to the need for more suitable materials and designs for constructing high‐performance on‐chip optoelectronic devices. Integrating emerging 2D materials with novel waveguide devices opens an avenue to boost the development of high‐performance optoelectronic waveguide devices operating in the mid‐IR wavelength range. This review summarizes the previous progress, current status, and future trends in exploring mid‐IR optoelectronic waveguide devices with 2D materials. Specifically, the authors focus on the research efforts of developing passive photonic devices, modulators, photodetectors, and light sources. Then, the challenges and prospects in this area are discussed. The paper provides a valuable reference for researchers in infrared physics, optoelectronics, integrated optics, material science, sensing, and spectroscopy.
A juvenile pleurosaurid (Lepidosauria: Rhynchocephalia) from the Tithonian of the Mörnsheim Formation, Germany
Authors: Beccari Victor , Villa Andrea , Jones Marc E. H. , Ferreira Gabriel S. , Glaw Frank , Rauhut Oliver W. M. 
Published: July 2024

AbstractLate Jurassic rhynchocephalians from the Solnhofen Archipelago have been known for almost two centuries. The number of specimens and taxa is constantly increasing, but little is known about the ontogeny of these animals. The well‐documented marine taxon Pleurosaurus is one of such cases. With over 15 described (and many more undescribed) specimens, there were no unambiguous juveniles so far. Some authors have argued that Acrosaurus, another common component of the Solnhofen Archipelago herpetofauna, might represent an early ontogenetic stage of Pleurosaurus, but the lack of proper descriptions for this taxon makes this assignment tentative, at best. Here, we describe the first unambiguous post‐hatchling juvenile of Pleurosaurus and tentatively attribute it to Pleurosaurus cf. P. ginsburgi. The new specimen comes from the Lower Tithonian of the Mörnsheim Formation, Germany. This specimen is small, disarticulated, and incomplete, but preserves several of its craniomandibular bones and presacral vertebrae. It shares with Pleurosaurus a set of diagnostic features, such as an elongated and triangular skull, a low anterior flange in its dentition, and an elongated axial skeleton. It can be identified as a juvenile due to the presence of an unworn dentition, well‐spaced posteriormost dentary teeth, a large gap between the last teeth and the coronoid process of the dentary, and poorly ossified vertebrae with unfused neural arches. Acrosaurus shares many anatomical features with both this specimen and Pleurosaurus, which could indicate that the two genera are indeed synonyms. The early ontogenetic stage inferred for the new Pleurosaurus specimen argues for an even earlier ontogenetic placement for specimens referred to Acrosaurus, the latter possibly pertaining to hatchlings.
Improving the Efficiency of Luminescent Zn(II)‐Modified N‐Doped GOQD Nanomaterials in Parkinson's Disease Treatment: A Theoretical Mechanistic Framework Exploring Doping Effect
Authors: Biswas Sneha , Chowdhury Tania , Banerjee Soumadip , Dutta Koushik , Das Abhijit K. , Das Debasis 
Published: July 2024

AbstractLevodopa, a widely prescribed drug in Parkinson's disease treatment, stands as the foremost prodrug of dopamine. An affordable self‐testing kit is utilized to monitor levodopa content in anti‐parkinson drugs in human serum. A photoluminescent trinuclear Zn(II) complex [Zn3(L)2(κ1‐OAc)2(κ2‐OAc)2] has been synthesized, which cleaves into mononuclear ZC in aqueous solution. ZC was found to detect L‐Dopa in Tris‐HCl buffer, exhibiting a moderate decrease in PL‐emission. The real‐life utility of the ZC probe is limited, for its lower sensitivity (LOD 35.3 μM) and separation challenges. Therefore, an interface between homogeneous and heterogeneous supports has been explored, leading to the strategic development of NGOZC, where ZC was grafted onto NGOQD (Graphene oxide quantum dots). This material enables naked‐ eye detection under both ambient and UV light with color change from bright cyan to green, followed by dark. The nitrogen doping effect was investigated by several comparative investigations involving the synthesis of ZC‐grafted GOQD, leading to enhanced quenching performance. Steady‐state and time‐resolved fluorescence titration study, morphological analysis, and computational calculations have been performed to get insights into the sensing mechanism. To the best of our knowledge, this as‐synthesized NGOZC (LOD 1.78 nM) represents a promising strategy and platform for applications in biosensors, especially for Parkinson's and Alzheimer's diseases.
Study on the enhanced efficacy mechanism of vinegar‐processed Cyperus rotundus in the treatment of primary dysmenorrhea
Authors: Wang Fengxia , Qian Qi , Feng Yu , Zhang Dongge , Wang Xinguo , Niu Liying 
Published: July 2024

AbstractThe enhanced efficacy of vinegar‐processed Cyperus rotundus (VCR) in treating primary dysmenorrhea (PD) has been observed. However, the active components and potential mechanisms of synergy are still unclear. The objective of this study was to develop a method that combines bionic technology, plant metabolomics and network pharmacology to discover the active components and potential mechanisms underlying the enhanced therapeutic effects of VCR for PD. Vinegar processing alters the flavor of C. rotundus, leading to changes in its properties. The acidic nature of vinegar enhances the selectivity of the medicine toward the liver, thereby improving its ability to soothe the liver, regulate qi and provide pain relief. Through gas chromatography–mass spectrometry and multivariate statistical analysis, 30 key differential components between raw C. rotundus and VCR have been screened and identified. These differential components primarily exert their therapeutic effects in treating PD by modulating targets such as interleukin‐6, TNF, TP53 and PTGS2, as well as pathways including the estrogen signaling pathway, ovarian steroidogenesis, the TNF signaling pathway and the HIF‐1 signaling pathway. The findings of this study serve as a reference for the application of VCR in compound formulas and clinic practiceal. Furthermore, the methodology employed in this study provides research insights for the processing of other Chinese medicines.
A simple and sensitive high‐performance liquid chromatographic method combined with fluorescence detection for bioanalysis of scopoletin in rat plasma: Application to a pharmacokinetic study
Authors: Kim Taeyoung , Han Dong‐Gyun , Yoon In‐Soo 
Published: July 2024

AbstractScopoletin, a coumarin class natural phytoalexin, is present in medicinal plants such as noni (Morinda citrifolia). It exhibits diverse pharmacological properties, including antioxidant, anti‐hyperuricemic, and anti‐inflammatory effects. The objective of this study was to develop a novel HPLC‐fluorescence (HPLC‐FL) method for the quantitative analysis of scopoletin in the plasma and to investigate its pharmacokinetics in rats. Sample preparation involved a methanol‐based protein precipitation method, and chromatographic separation was conducted using a C18 column with an isocratic mobile phase composed of water and acetonitrile containing 0.1% trifluoroacetic acid. The eluent was detected using an FL detector set to optimized excitation/emission wavelengths of 337/453 nm. Method validation encompassed assessments of selectivity, linearity (1–500 ng/mL), precision, accuracy, recovery, matrix effect, and stability in accordance with the prevailing Food and Drug Administration (FDA) guidelines. The developed method was successfully applied for pharmacokinetic study in rats. To the best of our knowledge, this study is the first application of a simple and sensitive HPLC‐FL method for the quantification of scopoletin in a pharmacokinetic study. This method offers a promising alternative for preclinical pharmacokinetic investigations with appropriate modifications and validations and holds potential for clinical applications.