bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combinatorial Ligand Assisted Simultaneous Control of Axial and Central Chirality in Highly Stereoselective C−H Allylation
Authors: Bhattacharya Trisha , Ghosh Supratim , Dutta Subhabrata , Guin Srimanta , Ghosh Animesh , Ge Haibo , Sunoj Raghavan B , Maiti Debabrata 
Published: November 2023

AbstractThe significance of stereoselective C−H bond functionalization thrives on its direct application potential to pharmaceuticals or complex chiral molecule synthesis. Complication arises when there are multiple stereogenic elements such as a center and an axis of chirality to control. Over the years cooperative assistance of multiple chiral ligands has been applied to control only chiral centers. In this work, we harness the essence of cooperative ligand approach to control two different stereogenic elements in the same molecule by atroposelective allylation to synthesize axially chiral biaryls from its racemic precursor. The crucial roles played by chiral phosphoric acid and chiral amino acid ligand in concert helped us to obtain one major stereoisomer out of four distinct possibilities.
Ligand‐Promoted Iron‐Catalyzed Nitrene Transfer for the Synthesis of Hydrazines and Triazanes through N‐Amidation of Arylamines
Authors: Zhu Shi‐Yang , He Wen‐Ji , Shen Guan‐Chi , Bai Zi‐Qian , Song Fang‐Fang , He Gang , Wang Hao , Chen Gong 
Published: November 2023

AbstractHerein, we report that bulky alkylphosphines such as PtBu3 can switch the roles from actor to spectator ligands to promote the FeCl2‐catalyzed N‐amidation reaction of arylamines with dioxazolones, giving hydrazides in high efficiency and chemoselectivity. Mechanistic studies indicated that the phosphine ligands could facilitate the decarboxylation of dioxazolones on the Fe center, and the hydrogen bonding interactions between the arylamines and the ligands on Fe nitrenoid intermediates might play a role in modulating the delicate interplay between the phosphine ligand, arylamine, and acyl nitrene N, favoring N−N coupling over N−P coupling. The new ligand‐promoted N‐amidation protocols offer a convenient way to access various challenging triazane compounds via double or sequential N‐amidation of primary arylamines.
Determination of Reaction Kinetics by Time‐Resolved Small‐Angle X‐ray Scattering during Polymerization‐Induced Self‐Assembly: Direct Evidence for Monomer‐Swollen Nanoparticles
Authors: Liao Guoxing , Derry Matthew J. , Smith Andrew J. , Armes Steven P. , Mykhaylyk Oleksandr O. 
Published: November 2023

AbstractThe kinetics of heterogeneous polymerization is determined directly using small‐angle X‐ray scattering (SAXS). This important advancement is exemplified for the synthesis of sterically‐stabilized diblock copolymer nanoparticles by reversible addition‐fragmentation chain transfer (RAFT) dispersion polymerization of benzyl methacrylate (BzMA) in mineral oil at 90 °C. The principle of mass balance is invoked to derive a series of equations for the analysis of the resulting time‐resolved SAXS patterns. Importantly, there is a continuous change in the X‐ray scattering length density for the various components within the reaction mixture. This enables the volume fraction of unreacted BzMA monomer to be calculated at any given time point, which enables the polymerization kinetics to be monitored in situ directly without relying on supplementary characterization techniques. Moreover, SAXS enables the local concentration of both monomer and solvent within the growing swollen nanoparticles to be determined during the polymerization. Data analysis reveals that the instantaneous rate of BzMA polymerization is proportional to the local monomer concentration within the nanoparticles. In principle, this powerful new time‐resolved SAXS approach can be applicable to other heterogeneous polymerization formulations.
Investigation of novel polyanilines as new antioxidants for ethylene propylene diene monomer rubber composites
Authors: Zidan T. A. , Kandil H. S. 
Published: November 2023

AbstractOxidative aging is a significant deterioration process that affects the performance and durability of rubber materials in various applications. Therefore, this study focuses on the development of new antioxidants‐based on polyaniline for ethylene propylene diene monomer (EPDM) rubber to enhance its resistance to oxidative aging. The novel polyanilines were prepared using in situ polymerization method and characterized using Fourier transforms infrared (FTIR) and thermogravimetric analysis (TGA). FTIR illustrates the success synthesis of polyanilines as it shows their characteristic functional groups. The thermal stability of the formed polyanilines is discussed through TGA and derivative of thermogravimetry (DTG) curves. The curves prove the good thermal stability of the synthesized polymers. The prepared polyaniline compounds were mixed to carbon black filled‐EPDM rubber composites using a roll mill and then vulcanized using sulfur curing process. Accelerated aging tests for the prepared EPDM rubber composites were conducted to evaluate the effectiveness of the antioxidants. Moreover, their impact on rheometer, mechanical, and swelling properties was studied. The results showed that the EPDM samples with the prepared polyaniline compounds exhibited improved oxidative properties compared to the EPDM sample with commercial antioxidant 2,2,4‐trimethyl‐1,2‐dihydroquinoline. These findings suggest that the novel antioxidants have the potential to enhance the durability and performance of EPDM rubber in various applications.
Metallaaromatic Complexes as Candidates for Future Molecular Materials and Electronic Devices: Recent Advancements
Authors: Yang Xiao Fei , Zhang Ming‐Xing , Liu Sheng Hua , Hartl František 
Published: November 2023

AbstractIn recent years, the field of organometallic chemistry has made a great progress and diverse types of metallaaromatics have successively been reported. In those studies, incorporation of ligated osmium centers into metallaaromatic systems played a prominent role. The reviewed literature documents that certain metallaaromatics with unconventional photophysical properties, redox and electronic transport properties and magnetism, have potential to be widely used in diverse practical applications, with selected examples of amino acid and fluoride anion identification, photothermal effects, functional materials, photodynamic therapy (PDT) in biomedicine, single‐molecule junction conductors, and electron‐transport layer materials (ETLs) in solar cells.
Advances in three dimensional metal enhanced fluorescence based biosensors using metal nanomaterial and nano‐patterned surfaces
Authors: Goodrum Rebecca , Li Huiyan 
Published: November 2023

AbstractMetal enhanced fluorescence (MEF) is a phenomenon that increases fluorescence signal through placement of metal near a fluorophore. For biosensing applications, MEF‐based biosensors are becoming increasingly popular as it enables highly sensitive detection of molecules, important for early diagnosis. The structure and size of the metal influence the optical properties through enhancing the fluorophore photostability and light absorption and emission. In recent years, many metal nanostructures have been fabricated and examined for their effectiveness in developing MEF‐based biosensors. This review focuses on the latest applications of three‐dimensional nanostructures and nano‐patterned surfaces used to develop and improve fluorescence sensing via MEF. Current reviews mostly discussed the applications of two dimensional MEF and metal‐nanoparticles‐based MEF with a focus on fabrication of nanoparticles and metal substrates. In this article, we focused more on the effect of the metal nanostructure and size on MEF and then provided an in‐depth summary of the performance of the state‐of‐the‐art three dimensional MEF‐based biosensors. While more work is needed to demonstrate applicability for complex samples, it is evident that with the use of metal nanoparticles and three dimensional nano‐patterns, the assay sensitivity of fluorescence‐based detection can be greatly improved, making it suitable for use in early disease diagnostics.
Liver‐tumor mimics as a potential translational framework for planning and testing irreversible electroporation with multiple electrodes
Authors: Vera‐Tizatl Adriana Leticia , van der Hee Regine , Cornelissen Jeroen , Vera‐Tizatl Claudia Elizabeth , Abayazid Momen , Fütterer Jurgen J. 
Published: November 2023

AbstractIrreversible electroporation (IRE) has emerged as an appealing non‐ionizing, non‐thermal ablation therapy, independent of antineoplastic drugs. Limited but successful outcomes in IRE conducted in vivo, in small focal hepatocellular carcinomas (HCC), have been reported. Nonetheless, the electric parameters of IRE are usually delivered in an unplanned manner. This work investigates the integration of computational modeling to hydrogels mimicking the HCC microenvironment, as a powerful framework to: circumvent ethical concerns of in vivo experimentation; safely tune the electric parameters reaching the IRE electric field threshold; and propel the translation of IRE as a routine clinical alternative to the treatment of HCC. Therefore, a parametric study served to evaluate the effects of the pulse amplitude, the number of pulses and electrodes, the treatment time, the hydrogel–tumor size, and the cell type. The ablation extent was surveyed by confocal microscopy and magnetic resonance imaging (MRI) in cylindrical and realistic tumor‐shaped hydrogels, respectively. A large ablation (70%–100%) was verified in all constructs.
Post‐purchase effects of impulse buying: A review and research agenda
Authors: Obukhovich Svetlana , Sipilä Jenni , Tarkiainen Anssi 
Published: November 2023

AbstractAlthough impulse buying has been studied for decades, prior research mostly focuses on reasons for impulse buying rather than its outcomes. In recent years this trend has changed, due to the emerging sustainability agenda and the attention to impulse buying as one of the main antecedents of overconsumption. However, existing research on the outcomes of impulse buying is currently less systematically synthesised compared to research on the antecedents. Therefore, we present a framework‐based systematic literature review on the outcomes of impulse buying based on 54 articles, drawing on the frameworks of theory, context, characteristics and methods (TCCM) and antecedents–decisions–outcomes (ADO). The results include a review and classification of impulse buying outcomes and their interconnections. This study unpacks the outcomes of impulse buying for consumers, society and business. The review also includes impulse buying antecedents to the extent that they are connected to the outcomes. Furthermore, we derive a conceptual framework of the impulse buying process that reveals the cyclic nature of impulse buying. Based on the findings, recommendations for future research are provided under the prism of theoretical, methodological, contextual, and conceptual development. The review also has implications for businesses and policymakers.
Source, Synthesis, and Biological Evaluation of Natural Occurring 2,2′‐Bipyridines
Authors: Sharma Amar Nath , Verma Rajni 
Published: November 2023

AbstractMolecules containing bipyridine scaffold are fascinating and versatile compounds in the field of natural product chemistry and drug discovery, and these molecules have possible therapeutic applications due to possession of potent biological activities such as antimicrobial, immunomodulatory, antitumor, and phytotoxic. Significant efforts have been devoted to isolating various 2,2′ bipyridine compounds from natural sources, with antimicrobial, anti‐cancer, and immunosuppressive properties. This review describes recent developments in isolation from different microbial origins, synthesis, and investigation of different kinds of biological activities of 2,2′ bipyridines, with a particular emphasis on caerulomycins, collismycins, and related derivates thereof in detail.
Benchmarking La‐Based Perovskites as Bifunctional Cathodes For Primary and Rechargeable Zinc−Air Batteries with Biopolymer‐Based Electrolyte
Authors: Frattini Domenico , Hernando‐Cuadra Alvaro , Accardo Grazia , García‐Gaitán Estibaliz , Bonilla Francisco , Letona‐Elizburu Arantzazu , Cid Rosalía , Ortiz‐Vitoriano Nagore 
Published: November 2023

AbstractState‐of‐the‐art perovskite‐based electrocatalysts for zinc−air batteries (ZABs) may include one or more Critical Raw Materials (CRMs) like Co, Ru, and rare earth elements, for oxygen reduction/evolution reactions. Under the warnings described by the CRMs Act in Europe, future research in this field must limit the use of these elements, find more sustainable formulations, and better design/integration strategies to trade off costs, supply, and performances. In this benchmarking study, three main perovskites, i. e., LaNiO3‐δ (LNO), LaMnO3+δ (LMO), and LaMn0.5Ni0.5O3 (LMNO), are studied as quasi‐CRM‐free benchmarks and integrated with a novel gel electrolyte from a natural biopolymer in primary and secondary ZABs. By comparing literature performances based on the number of total/active site CRMs for the first time, these reference perovskites showed Zn utilizations >90 % in primary ZABs, with LMO and LMNO approaching 94 % at 2 mA/cm2, the highest result in the field. In secondary ZABs, LMO demonstrated limited cyclability (62 cycles), while LMNO had a moderate number of cycles (117 cycles) and the highest round‐trip efficiency (54.3 %), while LNO presented the lowest charge potential (2.04 V) and longer cyclability (455 cycles). This work demonstrates encouraging performance with fewer CRMs and proper integration in more sustainable ZABs, opening the way to future CRM‐free perovskites.
Urea‐Promoted Neat Synthesis of Fused Dihydroisoquinolines and Disubstituted Pyridines: A Mechanistic Observation with Molecular‐Sensing Studies
Authors: Azad Sk Abulkalam , Bera Anirban , Samanta Jayanta , Sepay Nayim , Jana Rathin , Pal Chandan Kumar , Molla Mijanur Rahaman , Maiti Debabrata , Samanta Shubhankar 
Published: November 2023

AbstractAn efficient and short synthesis of fused dihydroisoquinolines, diaryl substituted pyridine derivatives in good to high yields has been established by using an environmentally safe, solvent‐metal‐oxidant‐free tandem approach. In this article, we discuss how the electrocyclic reaction is more pronounced in the solid phase in the presence of urea, whereas the typical aza‐Michael addition is more prominent in presence of arylamine in the solution phase for 3‐(2‐formylcycloalkenyl)acrylic ester derivative substrates. The wide range of substrates and urea‐promoted neat synthesis made our approach more significant in medical and also analytical science. Moreover, an isoquinoline alkaloid decumbenine B analogue has been synthesized by using our newly developed neat methodology. We have also investigated the photophysical properties of the synthesized fused dihydroisoquinoline derivatives. One of the synthesized molecules was used as a sensor for the selective detection of toxic picric acid. Therefore, the effective neat synthesis and molecular sensing applications of these compounds made our approach more exciting in the field of heterocyclic chemistry.
Adaptive Doppler bio‐signal detector and time‐frequency representation based on non‐Liènard oscillator
Authors: Pancóatl‐Bortolotti Pedro , Enríquez‐Caldera Rogerio A. , Costa Antonio H. , Tello‐Bello Maribel , Guerrero‐Castellanos Jose F. 
Published: November 2023

AbstractThe work presented here provides the guidelines and results for designing and implementing a highly sensitive modified Van der Pol – Duffing oscillator with a trigonometric damping function (VTD). This VTD can exhibit periodic and quasi‐chaotic behavior necessary for application in weak signal detection. Here, we present two proposals: (1) A method based on a quasi‐chaotic intermittent array (ANLIOA), whose all VTD parameters are calculated and fine‐tuned toward a critical state between chaotic and periodic state through a Lyapunov exponent procedure, and (2) A method based on a single oscillator in an adaptive stopping oscillation system (ANLSOS), where VTD is established within an oscillatory regime. Both systems can detect non‐stationary signals while reconstructing the time‐frequency spectrogram in high resolution within severe noise conditions. The systems were adapted for the detection of a synthesized Doppler signal corresponding to the blood flow velocity profile from an artery. Comparative results using typical oscillators such as Duffing or Van der Pol demonstrate the superiority of the VTD oscillator in detection when used for both methods, whose mean absolute percentage error reached around 6% for a signal‐to‐noise ratio (SNR) of −10 dB. Furthermore, compared to other time‐frequency methods, ANLIOA and ANLSOS promise high precision in detecting Doppler signals with low rates of frequency changes while minimizing energy emission and avoiding possible bio‐thermal effects.
Improving targeted small molecule drugs to overcome chemotherapy resistance
Authors: Rismanbaf Amirhossein 
Published: November 2023

AbstractBackgroundConventional cancer treatments face the challenge of therapeutic resistance, which causes poor treatment outcomes. The use of combination therapies can improve treatment results in patients and is one of the solutions to overcome this challenge. Chemotherapy is one of the conventional treatments that, due to the non‐targeted and lack of specificity in targeting cancer cells, can cause serious complications in the short and long‐term for patients by damaging healthy cells. Also, the employment of a wide range of strategies for chemotherapy resistance by cancer cells, metastasis, and cancer recurrence create serious problems to achieve the desired results of chemotherapy. Accordingly, targeted therapies can be used as a combination treatment with chemotherapy to both cause less damage to healthy cells, which as a result, they reduce the side effects of chemotherapy, and by targeting the factors that cause therapeutic challenges, can improve the results of chemotherapy in patients.Recent FindingsSmall molecules are one of the main targeted therapies that can be used for diverse targets in cancer treatment due to their penetration ability and characteristics. However, small molecules in cancer treatment are facing obstacles that a better understanding of cancer biology, as well as the mechanisms and factors involved in chemotherapy resistance, can lead to the improvement of this type of major targeted therapy.ConclusionIn this review article, at first, the challenges that lead to not achieving the desired results in chemotherapy and how cancer cells can be resistant to chemotherapy are examined, and at the end, research areas are suggested that more focusing on them, can lead to the improvement of the results of using targeted small molecules as an adjunctive treatment for chemotherapy in the conditions of chemotherapy resistance and metastasis of cancer cells.
Design of smart nanoparticles for the electrochemical detection of 3,4‐methylenedioxymethamphetamine to allow in field screening by law enforcement officers
Authors: Truta Florina Maria , Cruz Alvaro Garcia , Dragan Ana‐Maria , Tertis Mihaela , Cowen Todd , Stefan Maria‐Geogia , Topala Tamara , Slosse Amorn , Piletska Elena , Van Durme Filip , Kiss Bela , De Wael Karolien , Piletsky Sergey A. , Cristea Cecilia 
Published: November 2023

AbstractA portable and highly sensitive sensor was designed for the specific detection of 3,4‐methyl‐enedioxy‐methamphetamine (MDMA), in a range of field‐testing situations. The sensor can detect MDMA in street samples, even when other controlled substances drugs, or adulterants are present. In this work, we report for the first time a sensor using electroactive molecularly imprinted polymer nanoparticles computationally designed to recognize MDMA and then produced using solid phase synthesis. A composite comprising chitosan, reduced graphene oxide, and molecularly imprinted polymer nanoparticles synthesized for MDMA for the first time was immobilized on screen‐printed carbon electrodes. The sensors displayed a satisfactory sensitivity (106.8 nA × μM−1), limit of detection (1.6 nM; 0.31 ng/mL), and recoveries (92–99%). The accuracy of the results was confirmed through validation using Ultra‐High Performance Liquid Chromatography coupled with tandem Mass Spectrometry (UPLC‐MS/MS). This technology could be used in forensic analysis and make it possible to selectively detect MDMA in street samples.
Palladium‐Catalyzed Heck Type Regioselective β‐Vinylation of Thiophenes Using a Bromo Substituent as Traceless Directing Group
Authors: Liu Linhao , Doucet Henri 
Published: November 2023

AbstractFunctionalization of β‐C−H bonds of thiophenes such as their vinylation is more challenging than for their α‐positions. The use of Pd‐catalysis allowed us to vinylate such thienyl β‐positions. Oxidative addition of 2‐(2‐bromoaryl)thiophenes to palladium followed by a Pd 1,4‐migration activates these thienyl β‐C−H positions, then, classical Pd‐catalyzed Heck reaction gives the β‐vinylated 2‐arylthiophene derivatives. In the course of this coupling reaction, the bromide substituent on the aryl unit acts as a traceless directing group. It should also be mentioned that the created C−C bond results from the functionalization of two C−H bonds. This synthesis scheme tolerates a range of substituents on both the aryl ring and the alkene. In addition, this procedure employs an easily available air‐stable catalyst and an inexpensive base. This reaction allows the programmed Pd‐catalyzed synthesis of 2,3,5‐trisubstituted thiophenes using first Suzuki C2‐coupling, then Pd‐catalyzed direct C5‐arylation and finally Pd 1,4‐migration Heck C3‐vinylation.
Contextual factors in persistent severe back pain: A longitudinal analysis among German employees
Authors: Zimmer Julia‐Marie , Fauser David , Golla André , Bethge Matthias , Mau Wilfried 
Published: November 2023

AbstractBackgroundChronic back pain in employees compromises participation in social and daily activities, as well as work.ObjectivesTo examine the severity of back pain after 2 years and identify factors predicting stagnation at this level of pain.MethodsData were derived from a prospective cohort study with randomized sampling of insurants in the German Pension Insurance using a questionnaire at baseline and follow‐up after 2 years. The sample consisted of middle‐aged employees (45–59 years) with strong limitations due to back pain (Chronic Pain Grade III or IV), who had not applied for disability pension and did not use medical rehabilitation in the previous 4 years before baseline. Stepwise multivariable logistic regression models with backwards selection were used to identify relevant contextual factors in the stagnation of severe back pain.ResultsOf 1208 persons with severe back pain at baseline, 48% had stagnated at that pain level after 2 years. Predictors of persistent severe back pain were older age, poorer general health, more additional disabling conditions, more depressive symptoms, caregiving burden, less pain‐related self‐efficacy and more fear avoidance beliefs.ConclusionsIn a high‐risk subgroup with several co‐existing conditions, this analysis highlights (mental) health, social and personal (contextual) factors associated with long‐term unfavourable back pain progression.SignificanceBack pain is a condition that often has a chronic or recurrent course, threatening participation in many areas of life. In this study it was found that the unfavourable condition of severe back pain can remain stable for long periods of time in a significant proportion of sufferers. Contextual factors (self‐efficacy, fear‐avoidance beliefs, caregiving burden) as well as additional health problems should be considered when identifying persons with stagnating pain courses.