bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of ethanol vapor explosion and prediction based on chemical kinetics under high temperature and pressure
Authors: Qi Yingquan , Ding Li , Pan Yong , Liu Jingran , Wang Supan 
Published: December 2023

AbstractThe study of the explosion parameters of ethanol–air mixture at high pressure and temperature is essential for the safe production of ethanol. However, the explosion characteristics of ethanol vapor at various pressures and temperatures are limited. The mechanism at the flammability limits of ethanol has not been clarified, and the corresponding prediction model is also lacking. In this study, chemical kinetics and machine learning are used to study the mechanism of ethanol explosion and build predictive models, respectively. Our findings show that an increase in the initial pressure has a more pronounced influence on the explosion pressure (Pex) and pressure rise rate (dp/dt) than an increase of temperature. The variation trend of the upper flammability limit (UFL) of ethanol is related to the different effects of temperature and pressure on OH radicals. H + O2<>OH + O and HO2 + CH3<>OH + CH3O had the greatest effect on the generation of OH radicals. The quantitative relationship between the H, O, and OH radicals and UFL was constructed by machine learning, providing a new research perspective for the prediction of the UFL of an inflammable fuel under different pressures and temperatures. The results of the study will provide theoretical and practical guidance for the prevention and control of explosions in the ethanol production process.
Effect of BN substitution on structure, reactivity and spectroscopic properties of polyarylenevinylene systems: A computational insight
Authors: Adhaduk Krishna , Yadav Sunil , Kumar Deepak 
Published: December 2023

AbstractLinearly conjugated systems in organic chemistry reveal the intriguing relationship between structure and electronic properties. Such systems, characterized by alternating single and multiple bonds, possess unique electronic traits with practical applications in organic electronics. Carbon‐bridged oligophenylenevinyles (COPVs) are promising candidates for enhanced charge transport. However, their synthesis efficiency poses challenges. Heteroatom substitution, particularly BN dative bonding, enhances stability without compromising electronic properties. DFT calculations performed on Carbon‐bridged naphthylmethyl vinylenes (CNMVs) and Boron and carbon bridged quinolylmethyl vinylenes (BQMVs) reveal altered absorption and vibrational behaviors due to BN substitution. Hirshfeld charge analysis and dual descriptor assessment highlight modified electrophilic and nucleophilic regions, showcasing adaptability in functional groups. BN substitution also resulted in a notable decrease in the HOMO–LUMO gap of both CNMV1 and CNMV2. In CNMV1, the HOMO–LUMO gap dropped from 3.75 to 3.37 eV, and in CNMV2, the HOMO–LUMO gap narrowed from 3.16 to 2.80 eV. This research explores the structural and electronic aspects of conjugated molecules, emphasizing the potential of heteroatom substitution for tailored applications in organic electronics.
Nonfragile security control for time‐varying cyber‐physical systems operating over multipath networks
Authors: Di Jianying , Tan Cheng 
Published: December 2023

AbstractThe main focus of this article is to explore the finite‐time stabilization of time‐varying cyber‐physical systems (CPS) that are operating over multipath networks and under random denial‐of‐service (DoS) attacks. In contrast to prior studies, we present a set of necessary and sufficient conditions for achieving finite‐time stability in the closed‐loop model of CPS operating over single‐path network. Notably, this equivalent conditions are established based on the analysis of the state transition matrix (STM). Additionally, we utilized auxiliary systems to study more general CPS operating over multipath networks and obtained a sufficient condition based on STM. Finally, we address a sufficient condition based on the Lyapunov function and introduce a linear matrix inequality (LMI)‐based approach that facilitates the computation of nonfragile controllers. The effectiveness of the developed theoretical results is verified through a stock investment model.
Properties of the full random‐effect modeling approach with missing covariate data
Authors: Nyberg Joakim , Jonsson E. Niclas , Karlsson Mats O. , Häggström Jonas 
Published: December 2023

During drug development, a key step is the identification of relevant covariates predicting between‐subject variations in drug response. The full random effects model (FREM) is one of the full‐covariate approaches used to identify relevant covariates in nonlinear mixed effects models. Here we explore the ability of FREM to handle missing (both missing completely at random (MCAR) and missing at random (MAR)) covariate data and compare it to the full fixed‐effects model (FFEM) approach, applied either with complete case analysis or mean imputation. A global health dataset (20 421 children) was used to develop a FREM describing the changes of height for age Z‐score (HAZ) over time. Simulated datasets (n = 1000) were generated with variable rates of missing (MCAR) covariate data (0%‐90%) and different proportions of missing (MAR) data condition on either observed covariates or predicted HAZ. The three methods were used to re‐estimate model and compared in terms of bias and precision which showed that FREM had only minor increases in bias and minor loss of precision at increasing percentages of missing (MCAR) covariate data and performed similarly in the MAR scenarios. Conversely, the FFEM approaches either collapsed at 70% of missing (MCAR) covariate data (FFEM complete case analysis) or had large bias increases and loss of precision (FFEM with mean imputation). Our results suggest that FREM is an appropriate approach to covariate modeling for datasets with missing (MCAR and MAR) covariate data, such as in global health studies.
Two Olefin‐Linked Conjugated Microporous Polymers with Good Stability and Porosity for Carbon Dioxide Uptake
Authors: Cheng Guiqing , Han Yuxi 
Published: December 2023

AbstractConjugated microporous polymers (CMPs) are a novel kind of porous polymers with high‐conjugated and micro‐pore skeleton, achieving various functions. Due to the diversity of reactions and variety of building blocks, many synthetic methods have been used for the development of CMPs. Here, we have designed two olefin‐linked OL‐CMPs via the aldol condensation under solvothermal conditions. Both OL‐CMPs showed high porosity and excellent stability. A high surface area of OL‐CMP‐1 was up to 945 m2 g−1 and micropore size was observed at 0.92 nm. The OL‐CMP‐1 and OL‐CMP‐2 indicated good carbon dioxide capture owing to their micropore skeleton and rich heteroatoms via the weak interaction.
Temperature Dependent Solubility and Catalytic behaviour of K2CO3 and Na2CO3 during Transesterification of Calophyllum Inophyllum Oil and its Fuel Properties
Authors: Rajagopalachar Sreekanth 
Published: December 2023

AbstractThe current work is focused on the solubility and catalytic behaviour of K2CO3, and Na2CO3 during the synthesis of biodiesel from Calophyllum Inophyllum oil (CIO) in methanol. The solubility of K2CO3, and Na2CO3 in methanol is not straight forward, as both form their respective methoxides and bicarbonates on solubility in methanol. Therefore to understand catalytic behaviour of both carbonates, it is essential to estimate sodium and potassium methoxides, and bicarbonates formed at different temperatures. In this regard, the catalytic behaviour of both carbonates was studied between 50 °C to 65 °C. Therefore, solubility behaviour of both carbonates explored during the synthesis of biodiesel from CIO by transesterification process. At higher temperature, the concentration of potassium and sodium methoxides decreased and their bicarbonate concentration increased. This solubility behaviour found to be more useful to differentiate homogeneous and heterogeneous catalytic route for biodiesel synthesis. At higher temperature, 65 °C, K2CO3, and Na2CO3 exhibited heterogeneous catalytic behaviour, but Na2CO3 showed relatively higher heterogeneous catalytic behaviour as it form higher concentration of insoluble sodium bicarbonate. Therefore, Na2CO3 could be a better heterogeneous catalyst for biodiesel synthesis at higher temperatures, 65 °C, as it produces low concentration of sodium methoxide which is an advantage from post biodiesel treatment standpoint.
Exploration of N‐Tetra‐Substituted Imidazoles as Effective Agents To Counteract Gastric Cancer Cell Viability: Synthesis and Biological Evaluation
Authors: Ganesh Bharathi Hassan , Aruchamy Baladhandapani , Ramani Prasanna , Zara Susi , Carradori Simone , D'Agostino Silvia , Mathew Bijo 
Published: December 2023

AbstractThe tetra‐substituted imidazole offers more possibilities for modification and functionalization, allowing for fine‐tuning of the compound‘s biological activity. The substituents attached to the imidazole ring can be strategically chosen to introduce specific functional groups, steric effects, or electronic properties, thereby influencing the compound‘s overall bioactivity. An efficient one‐pot synthesis of 2,4,5‐tri and 1,2,4,5‐tetrasubstituted imidazoles was performed, which involves benzyl (1,2‐diphenylethane‐1,2‐dione), N‐methyl pyrrole‐2‐carboxaldehyde, appropriate primary amine, ammonium acetate, and iodine as a catalyst. The N‐alkylation on the imidazole was performed to introduce alkyl chains. All six synthesized compounds were purified, characterized using spectroscopic techniques, and tested against the primary Human Gingival Fibroblasts (HGFs) and AGS gastric adenocarcinoma cell line to assess their effect on cell viability. All the tested molecules displayed a low percentage of dead cells >50 μM on HGFs; compounds 1‐butyl‐2‐(1‐methyl‐1H‐pyrrol‐2‐yl)‐4,5‐diphenyl‐1H‐imidazole (5b) and 2‐(1‐methyl‐1H‐pyrrol‐2‐yl)‐1‐pentyl‐4,5‐diphenyl‐1H‐imidazole (5c) have demonstrated a remarkable ability to counteract cell viability than the other compounds, specifically on AGS cells, up to a concentration of 10 μM. This suggests that these two compounds have a higher potency in reducing the viability of AGS cells than the other tested compounds. These results align with current studies highlighting the enhanced anticancer efficacy of imidazole‐pyrrole hybrids against AGS cell line.
SO3H‐Functionalized Carbon Materials: A Versatile and sustainable heterogeneous Catalyst for Diverse Organic Transformations
Authors: Singh Ruby , Yadav Sunita , Bhardwaj Diksha , Saini Munna Ram 
Published: December 2023

AbstractDue to their fascinating biological features, heterocyclic compounds and their derivatives have long been recognized as promising molecules with potential pharmaceutical applications. The significance of heterocyclic compounds in drug discovery and development is evident from the fact that a majority of drugs in the pharmaceutical market incorporate heterocyclic compounds as active substances or ingredients. Various synthetic methods and advancements have been devised to prepare these heterocyclic compounds using diverse catalysts under mild reaction conditions. SO3H functionalized carbon material (C‐SO3H) is heterogeneous green solid catalyst that has been employed to catalyze diverse organic reactions including construction of three‐, four‐, five‐, six‐member and fused heterocycles as well as other open chain organic transformations. The C‐SO3H catalyst works under relatively mild reaction conditions and recovered from the reaction mixtures for reuse. Various cheap carbon sources covering natural organic carbon matter and industrial waste already being used to synthesize SO3H‐functionalized acidic carbon catalyst for replacement of various homogeneous acid catalysts. The present review aims to highlight the organic reactions especially those connecting for heterocyclic synthesis catalyzed by sulfonated carbons (C‐SO3H) from 2010 to till date.
Mechanism of Hydroxylamine Hydrochloride‐Catalyzed Transamidation: Covalent Catalysis over Hydrogen Bonding
Authors: Zeng Yi , Zhao Yuexin , Yang Linhao , Jiang Yang 
Published: December 2023

AbstractTransamidation of acetamide with primary methylamine and benzylamine for secondary amide formation has been examined at the M06‐2X(SMD)/6‐311++G(2df,2p)//M06‐2X(SMD)/6‐31+G(d) level. Two alternative mechanisms are taken into account involving non‐covalent catalysis by hydrogen‐bonding (Path I) and covalent catalysis via hydroxamic acid formation (Path II). In Path I, hydroxylamine hydrochloride activates acetamide through hydrogen bonding in favor of nucleophilic attack of methylamine/benzylamine, while in Path II the initial nucleophilic attack of hydroxylamine generates the intermediate hydroxamic acid for subsequent aminolysis. In Path I and Path II, N‐path and O‐path are considered, where proton shifts to NH2 or via carbonyl oxygen with OH group generated for leaving NH3, respectively. Our computational results manifest that Path II via O‐path is more favorable with lower free energy barriers of 21.9 (ammonia‐mediated), 22.7 (methylamine‐mediated) and 23.0 kcal mol−1 (hydroxylamine‐mediated) than Path I for methylamine as nucleophile. The ammonia‐mediated Path II via O‐path for benzylamine as nucleophile is still the most favorable pathway, with a free energy barrier of 22.1 kcal mol−1. The preference of Path II over Path I is rationalized by NBO analysis. Our theoretical results give useful insight to design more effective catalysts for activating the carboxamide in the future.
Title: A Boron‐Chelating Piperazine‐Tethered Schiff Base Can Modulate Excitability in Brain Slices in a Specific Frequency Range
Authors: Basoglu Harun , Degirmencioglu İsmail , Ozturk Hilal , Yorulmaz Nuri , Aydin‐Abidin Selcen , Abidin Ismail 
Published: December 2023

AbstractThe ability of boron‐containing compounds to make various bonds with biological targets draws attention in their use as new therapeutic agents. In this study, the effect of a newly synthesized molecule with the short name fmpemboron, “Difluoro [2‐[([2‐[4‐(2,3,4‐trimethoxybenzyl)piperazin‐1‐yl]ethyl] imino‐κN)methyl]phenolato‐κO]boron (5)”on the excitability of neurons in the brain was investigated for the first time. First of all, fmpemboron was synthesized and characterized. Secondly, virtual scanning of the molecule was performed using ADME and molecular docking methods. Then, epileptiform activities were induced in mouse brain slices using Mg‐free or 4AP methods, and the effect of fmpemboron (5) at different concentrations was examined. The absorbance peak wavelength of fmpemboron (5) is between 330–340 nm and the fluorescence emission peak is 435 nm. According to ADME and molecular docking results, fmpemboron (5) can cross the blood‐brain barrier (BBB) and has affinity for the NMDA receptor. It also significantly reduces the power of oscillations between 8–12 Hz and 13–29 Hz in epileptiform activities generated by the Mg‐free method. Administration of 10 μM fmpemboron (5) had a modulatory effect on epileptiform activities, indicating that fmpemboron (5) can affect various neurological functions through NMDA channels. However, in‐vivo dose‐dependent studies are required to further investigate the effects of this novel molecule.
Micro‐Mesoporous Hierarchical Beta Zeolite and its Catalytic Application in Acetic Acid Benzylation
Authors: Koshti Hardik , Bandyopadhyay Mahuya , Bandyopadhyay Rajib 
Published: December 2023

AbstractHierarchical Beta zeolite with tailor‐made pore structure is prepared by post‐synthetic alkali (NaOH) treatment. XRD, FE‐SEM, ICP‐OES, 27Al & 29Si MAS NMR, and N2 sorption isotherms were used to explore the structural transformation of these materials. ICP‐OES analysis showed post‐synthetic base treatment resulting into tuning of the Si/Al ratio, thereby increasing the acidity of the sample. The acidic properties of materials were measured using acid‐base titration, Pyridine FTIR spectroscopy, and NH3‐TPD. Conversion of acetic acid to benzyl acetate by reacting with benzyl alcohol was studied using hierarchical and parent sample. The reaction was evaluated with theoretical and experimental approaches. Under optimum reaction conditions, desilicated Beta zeolite showed 93 % acetic acid conversion and 90 % benzyl acetate selectivity, as confirmed by GC and GC‐MS analyses. Theoretical analysis indicated direct relationship between rate constant and rising reaction temperature, in accordance with the principles of first‐order reaction kinetics (R2>0.95). The activation energy for acetic acid benzylation over Beta‐0.1 M NaOH was found to be 10.21 kJ mol−1, considerably lower value compared to previous reports.
Coumarin Derivatives: Mechanistic Insights and Promising Applications as Potential Alzheimer's Disease (AD) Therapeutic Agents
Authors: Joshi Rachana 
Published: December 2023

AbstractIn this review, the therapeutic potential of coumarin derivatives for Alzheimer's disease (AD) is examined. Coumarin derivatives are intriguing options for treating AD since they have a variety of chemical structures and display a wide range of pharmacological properties. The acetylcholinesterase (AChE) enzyme, which can improve cognitive function by boosting cholinergic neurotransmission, is inhibited by these compounds, which underlies their possible therapeutic effects. As a result of acetylcholinesterase inhibition provided by coumarin derivatives, cholinergic neurotransmission and cognitive performance are boosted. They also have anti‐oxidant and anti‐inflammatory qualities, which can mitigate the oxidative stress and neuroinflammation seen in AD. In addition, amyloid‐beta aggregation and tau hyperphosphorylation are decreased by coumarin derivatives, demonstrating the neuroprotective properties of these compounds. To properly assess their effectiveness, safety, and ideal dosage in AD patients, more studies and clinical trials are nonetheless required. Overall, coumarin derivatives hold promise as potential therapeutic options for Alzheimer's disease (AD), and continued investigation will contribute to the development of effective treatments for this devastating disease.
Insight into Indole‐Based Heterocyclic Scaffolds: A Medicinal Chemistry Perspective
Authors: Bendi Anjaneyulu , Versha  , Rajni  , Singh Lakhwinder , Taruna  
Published: December 2023

AbstractThe importance of indole‐based heterocycle scaffolds in medicinal chemistry has increased as a result of their significant pharmacological and biological characteristics. These compounds′ importance in the discovery and creation of cutting‐edge medications to treat a variety of diseases is an instance of their worth. The current study highlights the numerous methods available to create different indole‐based heterocycle scaffolds and their favourable medical uses with the literature that has been published up to 2023.
PIFA Mediated Synthesis of Bis‐1,2,4‐triazoloquinazolines as Potential Anticancer Agents on MCF‐7 Cancer Cells: Characterization, Molecular Docking, Antiproliferative and ADME Profile
Authors: Kumar Ravinder , Bains Omkar , Kamal Raj , Kumar Ajay , Kaur Satwinderjeet , Bansal Arubhi , Chetti Prabhakar 
Published: December 2023

AbstractA novel series of bis([1,2,4]triazolo)[4,3‐a][4′,3′‐c] quinazolines derivatives 2 a–2 o has been synthesis in good to excellent yields (74–86 %) under mild reaction conditions via bis(trifluoroacetoxy)iodobenzene (PIFA) mediated oxidative‐cyclization of corresponding 2,4‐bis(2‐(E)‐arylidenehydrazinyl) quinazolines 1 a–1 o. Formation of the targeted compounds has been supported using various spectroscopic tools (IR, 1H & 13 C‐NMR) and HRMS analysis. These bis([1,2,4]triazolo)[4,3‐a][4′,3′‐c] quinazolines derivatives were biologically screened for their antiproliferative activities against MCF‐7 cancer cells. Results indicate that among all synthesized derivatives, 3,7‐bis (4‐chlorophenyl) bis([1,2,4]triazolo)[4,3‐a : 4′,3′‐c]quinazoline (2 d) and 3,7‐bis(3‐methoxyphenyl)bis([1,2,4]triazolo)[4,3‐a : 4′,3′‐c]quinazoline (2 j) displayed uppermost cytotoxicity efficacy with GI50 value of 106.30 μM and 108.56 μM respectively. Furthermore, molecular docking studies have been carried out to investigate possible binding modes between active sites of the protein (PDB ID: 3 U6 J) and the target compounds. In addition to these results, ADME (adsorption, distribution, metabolism, excretion) analysis has also been carried out to study the pharmacokinetic properties of the targeted compounds.
Preparation and Upscaling of Zeolite@TiO2 Core‐shell for the Removal of Pb(II) and Methylene Blue Dye from Wastewater
Authors: Mittal Tanu , Kant Rishi , Goel Mohit 
Published: December 2023

AbstractThe present work reports the preparation and adsorption kinetics of a Zeolite@TiO2 multifunctional adsorbent for the removal of heavy metal (Pb(II)) and organic pollutants (methylene blue) from wastewater. The design of the material is a core‐shell having a porous core of zeolite and the surface is supported with the growth of nano TiO2 for a tunable surface and interface designing for efficient wastewater treatment. The formation of Zeolite@TiO2 core‐shell has been characterized by XRD, XPS, SEM, TEM, and DRS spectroscopic techniques. BET surface analysis indicated increased surface area for efficient adsorption. The design of multifunctional adsorbent acts as a charged crossing point for quick adsorption and breakdown of pollutants in water. The adsorption of Pb(II) and methylene blue (MB) dye follows the Freundlich adsorption isotherm confirming presence of multilayer of TiO2 in the adsorption process. Complete adsorption for Pb(II) is achieved in 25 minutes whereas MB dye is completely adsorbed within 15 minutes with high adsorption capacities. Photocatalytic degradation activity for MB dye were also analyzed and indicated 30 mg/l was degraded in 10 min. The DRS and photoluminescence life time study support good photocatalytic activity. The regeneration and recyclability of the core‐shell material have also been studied and reported.
Expedient Synthesis of 6‐Functionalized Azabicyclo[4.1.0]heptane Derivatives
Authors: Omelian Taras V. , Ostapchuk Eugeniy N. , Dobrydnev Alexey V. , Grygorenko Oleksandr O. 
Published: December 2023

AbstractAn efficient approach to the synthesis of previously unreported azabicyclo[4.1.0]heptane‐derived building blocks is reported following the divergent strategy. The common synthetic precursor – tert‐butyl 6‐(hydroxymethyl)‐3‐azabicyclo[4.1.0]heptane‐3‐carboxylate was obtained in four steps with 38 % overall yield and was involved in short reaction sequences (1–3 steps) to provide the target bifunctional derivatives, including novel bicyclic N‐Boc protected γ‐amino acid. The described compounds are interesting in terms of lead‐likeness concepts, according to which the rigid 3D‐shaped and sp3‐enriched frameworks are among the most promising entry points for drug discovery projects.
The Highly Selective, Aerobic Oxidation of Methane to Formaldehyde over Pt Supported on Carbon: Activity, Selectivity and Stability
Authors: Mahlaba Sinqobile V. L. , Govender Alisa , Leteba Gerard M. , van Steen Eric 
Published: December 2023

AbstractPlatinum on carbon is an effective catalyst (10 wt.% Pt) for the selective aerobic, oxidation of methane yielding formaldehyde. In the presence of liquid water, an unusually high conversion of methane of 4.2 % was achieved yielding selectively formaldehyde (98 %) with a turnover frequency of 0.50 hr−1. The conversion increases upon increasing the water content in the feed, which is accompanied by an increase in the selectivity for the formation of formaldehyde. This is attributed to enhanced desorption of the target product, formaldehyde, upon increased wetting of the catalyst surface. Unfortunately, the catalyst support is not stable under the applied, extremely hydrothermal conditions, but improved catalysts using a more hydrothermally stable support could be a promising route forward.