bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controlling the Relaxation Dynamics of Polymer Networks by Combining Associative and Dissociative Dynamic Covalent Bonds
Authors: Cornellà Aleix Costa , Furia Francesca , Van Assche Guy , Brancart Joost 
Published: September 2024

AbstractDynamic polymer networks offer a promising solution to key challenges in polymers such as recyclability, processability, and damage repair. However, the trade‐off between combining facile processability, fast self‐healing, and high creep resistance remains a major obstacle to implementation. To overcome this, two very distinct dynamic covalent chemistries, Diels–Alder and transesterification, is combined in a single network. The resulting dual dynamic networks offer an unprecedented set of properties and control over the relaxation times. The system decouples the relaxation dynamics of the network from the spatial motifs, and the tuning of the ratio between chemistries enables to control of the relaxation dynamics over six orders of magnitude. Taking advantage of this control, the composition and rheological behavior is optimized to drastically improve the resolution for extrusion‐based additive manufacturing of dynamic covalent networks. Additionally, two well‐defined and separated stress relaxation peaks are observed at compositions close to 50% of each dynamic chemistry, accentuating the double character of the system's relaxation dynamics. This atypical situation, enables to preparation of self‐healing materials with negligible creep, and with shape‐memory properties solely leveraging the two distinct relaxation dynamics, instead of the glass transition temperature or the melting point.
Ultrafast Intramolecular Singlet Fission in Homoconjugated Oligomers of Azapentacene with Rigid Connecting Unit
Authors: Kong Wei , Chen Hong , Li Jiaxin , Zhao Yilun , Deng Junpeng , Chen Wangqiao , Ma Lin 
Published: September 2024

AbstractA novel series of homoconjugated oligomers of azapentacene, linked via the rigid connecting unit bicyclo[2.2.2]octane bridge is presented. The investigation delves into intramolecular singlet fission (iSF) within these dimeric and trimeric frameworks, employing various time‐resolved spectroscopies and quantum chemical calculations. Combining the merits of both through‐space and through‐bond couplings between the constituent chromophores within these rigid homoconjugated structures, iSF proceeds within a few picoseconds, exhibiting a 2–3 orders of magnitude acceleration compared to traditional covalently linked oligomers and achieving an iSF efficiency approaching unity. In the homoconjugated trimer, the larger interplanar angle between neighboring chromophores leads to a relatively slower iSF rate compared to that of the homoconjugated dimer. Furthermore, the active involvement of the charge transfer state is demonstrated to accelerate the iSF process in the trimer, while exerting no influence on the iSF process in the dimer. The study provides novel avenues for investigating the influence of molecular geometry on singlet fission and reveals the crucial role of the interplay between spatial and covalent coupling in facilitating intramolecular singlet fission.
A Wireless‐Driven Electric Responsive Long‐Lived Room Temperature Phosphorescent Switching Device
Authors: Yan Yan , Wang Yuyang , Wei Jinbei , Zhu Jinbao , Shen Ruipeng , Feng Yuliang , Zhang Weiran , Liu Xuesong , Wang Pengfei , Wang Hualiang , Zhang Yu‐Mo , Zhang Sean Xiao‐An , Lin Tingting 
Published: September 2024

AbstractLong‐lived room temperature phosphorescent (RTP) materials have prospective applications, but endowing long‐lived RTP materials with on‐off regulation property is challenging. Here, the first electric responsive long‐lived RTP switching device under photoexcitation with a wireless power transmission (WPT) system is demonstrated. It exhibits long persistent phosphorescence (180.1 ms for the film and 180.8 ms for the device) and excellent reversibility (>1000 cycles). Due to the effective dual‐state Förster resonance energy transfer (FRET) process from the triplet and singlet states of the chromophore donor to the singlet state of the dye acceptor, the devices exhibit switching characteristics. The appearance of the dye's absorption can be modulated by electro‐acid based on proton‐coupled electron transfer (PCET) mechanism, resulting in the device being electrically controlled. In addition, by integrating WPT coils outside the device, it can be driven wirelessly, thereby overcoming the reliance on electrical stimulation methods on the power supply. Finally, due to the multiple switching characteristics (color, fluorescence, phosphorescence) of this device, it is successfully applied in anti‐counterfeiting and information encryption.
Metal Centers Drive Selectivity of Electrocatalytic Oxygen Reduction Reaction Promoted by Tetrapyrazinoporphyrazine Complexes
Authors: Sordello Fabrizio , Azzi Emanuele , Pellegrino Francesco , Deagostino Annamaria , Renzi Polyssena 
Published: September 2024

AbstractFuel cells represent a promising technology for the future decarbonization of the mobility sector. However, the efficient use of H2 and O2 to produce electricity still requires noble metal catalysts such as platinum and ruthenium. In particular, the Oxygen Reduction Reaction (ORR) is complex and limiting due to its mechanism, which involves the transfer of four electrons and four protons to produce water. The search for alternative catalysts exhibiting high selectivity is progressing at a rapid pace. In this context, this group previously unveiled a homogeneous catalyst based on titanium‐centered tetrapyrazinoporphyrazines (TPyzPz) for the ORR, noting a certain modularity in the selectivity toward either a two‐ or four‐electron reduction reaction. In this study, the influence of different metal centers (magnesium (Mg), cobalt (Co), copper (Cu), and zinc (Zn)) and various substituents is investigated on the tetrapyrazinoporphyrazine ring. The findings indicate a strong dependence of activity and selectivity on these modifications. Notably, cobalt and copper catalysts exhibit a selectivity greater than 90% toward H2O production in the ORR. However, alterations to the macrocycle structure significantly affected the reactivity of these catalysts. These new insights highlighted the importance of careful structural design in the development of the next generation of ORR catalysts.
Exploiting Spatial Ionic Dynamics in Solid‐State Organic Electrochemical Transistors for Multi‐Tactile Sensing and Processing
Authors: Hou Kunqi , Chen Shuai , John Rohit Abraham , He Qiang , Zhou Zhongliang , Mathews Nripan , Lew Wen Siang , Leong Wei Lin 
Published: September 2024

AbstractThe human nervous system inspires the next generation of sensory and communication systems for robotics, human‐machine interfaces (HMIs), biomedical applications, and artificial intelligence. Neuromorphic approaches address processing challenges; however, the vast number of sensors and their large‐scale distribution complicate analog data manipulation. Conventional digital multiplexers are limited by complex circuit architecture and high supply voltage. Large sensory arrays further complicate wiring. An ʻin‐electrolyte computingʼ platform is presented by integrating organic electrochemical transistors (OECTs) with a solid‐state polymer electrolyte. These devices use synapse‐like signal transport and spatially dependent bulk ionic doping, achieving over 400 times modulation in channel conductance, allowing discrimination of locally random‐access events without peripheral circuitry or address assignment. It demonstrates information processing from 12 tactile sensors with a single OECT output, showing clear advantages in circuit simplicity over existing all‐electronic, all‐digital implementations. This self‐multiplexer platform offers exciting prospects for circuit‐free integration with sensory arrays for high‐quality, large‐volume analog signal processing.
Tumor Microenvironment Activated Cu Crosslinked Near‐Infrared Sonosensitizers for Visualized Cuproptosis‐Enhanced Sonodynamic Cancer Immunotherapy
Authors: Hu Jinyan , Yan Lang , Cao Zhi , Geng Bijiang , Cao Xiqian , Liu Bing , Guo Jiaming , Zhu Jiangbo 
Published: September 2024

AbstractReactive oxygen species (ROS)‐mediated sonodynamic therapy (SDT) holds increasing potential in treating deep‐seated tumor owing to the high tissue‐penetration depth. However, the inevitable accumulation of sonosensitizers in normal tissues not only make it difficult to realize the in situ SDT, but also induces sonodynamic effects in normal tissues. Herein, this work reports the passivation and selective activation strategies for the sonodynamic and near‐infrared (NIR) imaging performances of an intelligent antitumor theranostic platform termed Cu‐IR783 nanoparticles (NPs). Owing to the ruptured coordination bond between IR783 with Cu ions by responding to tumor microenvironment (TME), the selective activation of IR783 only occurred in tumor tissues to achieve the visualized in‐situ SDT. The tumor‐specific released Cu ions not only realized the cascade amplification of ROS generation through Cu+‐mediated Fenton‐like reaction, but also triggered cuproptosis through Cu+‐induced DLAT oligomerization and mitochondrial dysfunction. More importantly, the immunosuppressive TME can be reversed by the greatly enhanced ROS levels and high‐efficiency cuproptosis, ultimately inducing immunogenic cell death that promotes robust systemic immune responses for the eradication of primary tumors and suppression of distant tumors. This work provides a distinct paradigm of the integration of SDT, CDT, and cuproptosis in a controlled manner to achieve visualized in‐situ antitumor therapy.
Foams with 3D Spatially Programmed Mechanics Enabled by Autonomous Active Learning on Viscous Thread Printing
Authors: Emery Brett , Snapp Kelsey L. , Revier Daniel , Sarkar Vivek , Nakura Masa , Brown Keith A. , Lipton Jeffrey Ian 
Published: September 2024

AbstractFoams are versatile by nature and ubiquitous in a wide range of applications, including padding, insulation, and acoustic dampening. Previous work established that foams 3D printed via Viscous Thread Printing (VTP) can in principle combine the flexibility of 3D printing with the mechanical properties of conventional foams. However, the generality of prior work is limited due to the lack of predictable process‐property relationships. In this work, a self‐driving lab is utilized that combines automated experimentation with machine learning to identify a processing subspace in which dimensionally consistent materials are produced using VTP with spatially programmable mechanical properties. In carrying out this process, an underlying self‐stabilizing characteristic of VTP layer thickness is discovered as an important feature for its extension to new materials and systems. Several complex exemplars are constructed to illustrate the newly enabled capabilities of foams produced via VTP, including 1D gradient rectangular slabs, 2D localized stiffness zones on an insole orthotic and living hinges, and programmed 3D deformation via a cable‐driven humanoid hand. Predictive mapping models are developed and validated for both thermoplastic polyurethane (TPU) and polylactic acid (PLA) filaments, suggesting the ability to train a model for any material suitable for material extrusion (ME) 3D printing.
Wild introgression as an effective tool for aiding the expansion and adaptation of cultivated safflower
Authors: Majidi Mohammad Mahdi , Pirnajmedin Fatemeh , Espanani Soheila 
Published: September 2024

AbstractSafflower is a multipurpose crop grown in different regions, mainly for its high oil quality. Crop wild relatives serve as a valuable reservoir of genes that have been depleted due to evolutionary bottlenecks, which are poorly applied in safflower. During the last decade, we developed three populations from hybridization of safflower with its wild relatives and selected the superior lines to develop new varieties. From each of three different interspecific populations (TP: Carthamus tinctorius × Carthamus palaestinus, PO: C. palaestinus × Carthamus oxyacantha, and TO: C. tinctorius × C. oxyacantha), 10 genotypes were selected (a total of 30 lines) in the “F8” generation and were evaluated along with their parents (T, P, and O) and one control cultivar (Golsfid) at the field during 2019–2022 to assess genetic variation, estimate genetic parameters, and evaluate the stability. Considerable genetic variability for oil, seed yield, and other agronomic traits between and within the interspecific populations suggests the high potential of these new recombinant lines for introducing beneficial alleles. Our results indicated that recombinant inbred lines derived from the hybridization of TP were superior in terms of seed yield, oil content, and stability parameters. The use of stability indices of Wricke, Lin and Binns, Eberhart and Russell, and HMRPGVi, along with the biplot analysis, allowed the identification of preferable and stable safflower genotypes. Moderately high values of heritability were found for yield‐related traits. New recombinant lines can be introduced to the safflower gene pool to improve the genetic base of this valuable oil seed crop.
Violating Lorentz Invariance Minimally by the Emergence of Nonmetricity? A Perspective
Authors: Obukhov Yuri N. , Hehl Friedrich W. 
Published: September 2024

AbstractLorentz invariance belongs to the fundamental symmetries of nature. It is basic for the successful Standard Model of Particle Physics. Nevertheless, within the last decades, Lorentz invariance has been repeatedly questioned. In fact, there exist different research programs addressing this problem. It is argued that a most adequate understanding of a possible violation of Lorentz invariance is achieved in the framework of the gauge‐theoretic approach to gravity: a non‐vanishing nonmetricity of a metric‐affine geometry of spacetime heralds the violation of the Lorentz symmetry.
Interfacial Thermoconvection and Atomic Relay Catalysis Enable Equilibrium Shifting and Rapid Glucose‐to‐Fructose Isomerization
Authors: Huang Jinshu , Li Hu , Saravanamurugan Shunmugavel , Su Yaqiong , Yang Song , Riisager Anders 
Published: September 2024

AbstractThe aqueous glucose‐to‐fructose isomerization is controlled by thermodynamics to an equilibrium limit of ~50 % fructose yield. However, here we report an in situ fructose removal strategy enabled by an interfacial local photothermal effect in combination with relay catalysis of geminal and isolated potassium single atoms (K SAs) on graphene‐type carbon (Ksg/GT) to effectively bypass the equilibrium limit and markedly speed up glucose‐to‐fructose isomerization. At 25 °C, an unprecedented fructose yield of 68.2 % was obtained over Ksg/GT in an aqueous solution without any additives under 30‐min solar‐like irradiation. Mechanistic studies expounded that the interfacial thermoconvection caused by the local photothermal effect of the graphene‐type carbon and preferable glucose adsorption on single‐atom K could facilitate the release of in situ formed fructose. The geminal K SAs were prone to form a stable metal‐glucose complex via bidentate coordination, and could significantly reduce the C−H bond electron density by light‐driven electron transfer toward K. This facilitated the hydride shift rate‐determining step and expedited glucose isomerization. In addition, isolated K SAs favored the subsequent protonation and ring‐closure process to furnish fructose. The integration of the interfacial thermoconvection‐enhanced in situ removal protocol and tailored atomic catalysis opens a prospective avenue for boosting equilibrium‐limited reactions under mild conditions.
Switching Sides: Regiochemistry and Functionalization Dictate the Photoswitching Properties of Imines
Authors: Wu Jiarong , Kreimendahl Lasse , Greenfield Jake L. 
Published: September 2024

AbstractPhotoswitchable imines demonstrate light‐dependent dynamic covalent chemistry and can function as molecular ratchets. However, the design of aryliminopyrazoles (AIPs) has been limited to N‐pyrazole derivatives with ortho‐pyrrolidine motifs. The impact of other functionalization patterns on the photoswitching properties remains unknown. Here, we present a systematic structure‐property analysis and study how the photoswitching properties can be tuned through ortho‐ and para‐functionalization of the phenyl ring in N‐pyrazole and N‐phenyl AIPs. This study establishes the first set of design rules for these AIP photoswitches and reports the most stable Z‐isomer of an AIP to date, enabling its crystallization and resulting in the first reported crystal structure of a metastable Z‐aldimine. Finally, we demonstrate that the AIPs are promising candidates for photoswitching in the condensed phase.
One‐Pot Transition‐Metal‐Free Synthesis of Alkynyl Amides
Authors: Wu Yu , Sátiro Bárbara G. , Mao Jianyou , Walsh Patrick J. 
Published: September 2024

AbstractAlkynyl amides play crucial roles in organic synthesis in the production of bioactive compounds and valuable heterocycles. Despite numerous studies on their synthesis, challenges persist due to the necessity of harsh or hazardous conditions and the use of costly or unstable reagents. Herein, we present a one‐pot method for the synthesis of all three bonds of the alkyne under transition‐metal‐free conditions. An important feature of this chemistry is the use of readily available feedstock chemicals, such as methyl esters and acetamides. This approach offers efficient access to a wide range of aryl and alkyl alkynyl amides and demonstrates excellent tolerance towards various functional groups in a sustainable and cost‐effective manner.
Organic Materials with Ultrabright Phosphorescence at Room Temperature under Physiological Conditions for Bioimaging
Authors: Gu Juqing , Yuan Wentao , Chang Kai , Zhong Cheng , Yuan Yufeng , Li Jinghua , Zhang Yufeng , Deng Tian , Fan Yuanyuan , Yuan Likai , Liu Siwei , Xu Yongzhen , Ling Sisi , Li Chunyan , Zhao Zheng , Li Qianqian , Li Zhen , Tang Ben Zhong 
Published: September 2024

AbstractIn contrast to the high efficiency of room temperature phosphorescence in crystal states, the generally utilized nanoparticles of organic materials in bioimaging demonstrated sharply decreased performance by orders of magnitude under physiological conditions, badly limiting the realization of their unique advantages. This case, especially for organic red/near‐infrared (NIR) phosphorescence materials, is not only the challenge present in reality but more importantly, for the theoretical problem of deeply understanding and avoiding the quenching effect by oxygen and water toward excited triplet states. Herein, thanks to the intelligent molecular design by the introduction of abundant hydrophobic chains and highly‐branched structures, bright and persistent red/NIR phosphorescence under physiological conditions has been realized, which demonstrated the shielding effect towards oxygen, and the strengthened intermolecular interactions to suppress the non‐radiative transitions. Accordingly, the record phosphorescence intensity of nanoparticles in bioimage, up to 8.21±0.36×108 p s−1 cm−2 sr−1, was achieved, to realize the clear phosphorescence imaging of liver and tumors in living mice, even lymph nodes in rabbit models with high SBRs. This work afforded an efficient way to achieve the bright red/NIR phosphorescence nanoparticles, guiding their further applications in biology and medicine.
Fe−N Co‐Doped BiVO4 Photoanode with Record Photocurrent for Water Oxidation
Authors: Yang Jie , Deng Chaoyuan , Lei Yu , Duan Mengyu , Yang Yisen , Chen Xiaoran , Yang Sipeng , Li Jikun , Sheng Hua , Shi Weiqun , Chen Chuncheng , Zhao Jincai 
Published: September 2024

AbstractBismuth vanadate (BVO) ranks among the most promising photoanodes for photoelectrochemical (PEC) water splitting. Nonetheless, slow charge separation and transport, besides the sluggish water oxidation kinetics, are key barriers to its photoefficiency. Here, we present a co‐doping strategy that significantly improves the charge separation performance of BVO photoanodes. We found that, under standard one sun illumination, the Fe−N co‐doped BVO photoanode (Fe−N−BVO) by N‐coordinated Fe precursor reaches a record photocurrent density of 7.01 mA cm−2 at 1.23 V vs RHE after modified a surface co‐catalyst (FeNiOOH), and exhibits an outstanding stability. By contrast, much lower photocurrent density is obtained for the N‐doped, Fe‐doped and Fe/N‐doped BVO photoanode with separated N and Fe precursors. The detailed experimental characterizations show that the high activity of the Fe−N co‐doped BVO photoanode is attributed to the enhanced photo‐induced bulk charge separation, as well as the accelerated surface water oxidation kinetics. XPS, EXAFS and DFT calculations clearly show that, instead of formation of deep trapping state in the individually doped BVO, the co‐doping of Fe−N into BVO generates Fe‐based electronic states just below the bottom of conduction band and N‐derived states just above the top of valence band. Such modulations in electronic structure enable the efficient trap of the electrons and holes to enhance the separation of photo‐induced carriers, but hinder the charge recombination originated from the deep trapping sites.
Anticancer, Antihaemolytic and Anticoagulant Studies of Coumarin‐Substituted Sterically Tuned N‐Heterocyclic Carbene Silver(I) Complexes
Authors: Vickraman Ilavarasan , Shashidhara Vaishnavi , R. Thrilokraj , Małecki Jan Grzegorz , Alwarsamy Madhavarani , Ganapathy Kavina , Keri Rangappa S. , Budagumpi Srinivasa 
Published: September 2024

ABSTRACTA series of sterically varied silver‐based N‐heterocyclic carbene (NHC) complexes (14–17) were synthesized by embroidering biomedically active coumarin and 1,2,4‐triazole core as NHC precursors (10–13). The structure of all the synthesized salts (10–13) and complexes (14–17) were elucidated by FT‐IR and NMR (proton and carbon) spectroscopic techniques. Complex 15 was characterized by single‐crystal x‐ray diffraction. The data obtained from this characterization of the small molecule 15 confirmed the three‐dimensional arrangement of the complex. This also indicated agostic‐type interactions between the Ag atom and the CH modules of one of the NHC ligands. Further, the synthesized complexes (14–17) were studied for the antihaemolytic, anticoagulant and anticancer activities. The complexes 15 and 17 exhibited anticoagulant properties comparable to that of the standard anticoagulant EDTA. Notably, all the complexes evidenced anticancer activity on leukaemic cell lines (K562) with the IC50 values below 100 μM, the concentration at which antihaemolytic property was evidenced. Complex 15 exhibited the lowest IC50 value of 18.44 ± 0.76 μM, which could be attributed by the appropriate steric bulk around the metal atom. The cumulative data of the three analyses validate potential of the complexes 15 and 17 to exhibit antihaemolytic, anticancer and anticoagulant properties.