化学•材料最新文献

{"title":"Decoding Hairpin Structure Stability in Lin28-Mediated Repression.","authors":"Qiang Zhu, Limu Hu, Chang Cui, Min Zang, Hao Dong, Jing Ma","doi":"10.1021/acs.biochem.4c00675","DOIUrl":"https://doi.org/10.1021/acs.biochem.4c00675","url":null,"abstract":"<p><p>The Lin28 protein is well known for its role in inhibiting the biogenesis of microRNAs (miRNAs) that belong to the let-7 family. The Lin28 and let-7 axes are associated with several types of cancers. It is imperative to understand the underlying mechanism to treat these cancers in a more efficient way. In this study, we employed all-atom molecular dynamics simulation as a research tool to investigate the interaction formed between Lin28 and the precursor element of let-7d, one of the 12 members of the let-7 family. By constructing systems of an intact sequence length of preE-let-7d, our simulations suggest that both the loop region of the hairpin structure and the GGAG sequence can form stable interactions with the cold shock domain (CSD) and zinc knuckle domain (ZKD) regions of the protein, respectively. The system, by deleting the nucleotides GGAG at the 3' terminal, indicates that the loop region is more responsible for its ability in bypassing the binding and repression of Lin28. Additionally, using let-7c-2, which can bypass Lin28 regulation, as a template, we constructed systems with mutated loop region sequences in miRNAs and tested their stabilities. Our simulation results coincide well with experimental observations. Based on both simulation results and statistical analysis from two databases, we hypothesized that two factors, namely, the interaction between terminal nucleotides and the ring tension originating from the middle nucleotides, can significantly influence their stabilities. Systems combining strong and weak terminal interactions with large and small ring tensions were recruited to validate our hypothesis. Our findings offer a new perspective and shed light on strategies for designing sequences to regulate the interactions formed between proteins and hairpin structures.</p>","PeriodicalId":28,"journal":{"name":"Biochemistry Biochemistry","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthetic Protocol for Pyrido[2,3-<i>c</i>]pyridazine and Pyrido[3,2-<i>e</i>][1,2]oxazine Scaffolds via a [4 + 2] Cycloaddition Reaction.","authors":"Xiuyu Chen, Jing Sun, Ying Han, Chao-Guo Yan","doi":"10.1021/acs.joc.4c02525","DOIUrl":"10.1021/acs.joc.4c02525","url":null,"abstract":"<p><p>Here, we revealed a convenient synthetic protocol for unique pyrido[2,3-<i>c</i>]pyridazine and pyrido[3,2-<i>e</i>][1,2]oxazine scaffolds with excellent regioselectvity and diastereoselectivity. The functionalized pyrido[2,3-<i>c</i>] pyridazines were successfully synthesized via a Cs₂CO₃-promoted [4 + 2] cycloaddition reaction of α-halogenated <i>N-</i>tosylhydrazones or <i>N-</i>acylhydrazones and 5,6-unsubstituted 1,4-dihydropyridines under mild conditions. Additionally, the similar base-promoted [4 + 2] cycloaddition reaction of α-chlorogenated oximes and 5,6-unsubstituted 1,4-dihydropyridines afforded functionalized pyrido[3,2-<i>e</i>][1,2]oxazines in satisfactory yields. The features of this reaction included mild reaction conditions, broad substrate scopes, high functional group tolerance, and significant atomic economy.</p>","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":" ","pages":"2889-2906"},"PeriodicalIF":3.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143416854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanistic Insights into the Methylation and Formylation of Amines with CO₂: Exploring Diverse CO₂ Activation Models.","authors":"Pan Du, Ling Han, Xue Zhang, Qin Yu, Li Li, Jiyang Zhao","doi":"10.1021/acs.joc.4c02854","DOIUrl":"10.1021/acs.joc.4c02854","url":null,"abstract":"<p><p>The urgent need to address global warming and resource depletion has spurred research into sustainable methods for the utilization of CO₂ as a C1 source. However, the challenge remains in developing metal-free, cost-effective, and environmentally friendly approaches for CO₂ conversion. Here, we investigate the mechanisms of CO₂ activation in the methylation and formylation of amines using both theoretical and experimental approaches. Our study reveals that the methylation process is complex, with the \"double H model\" proving most effective, while the formylation reaction is more straightforward, favoring the \"single H model.\" Control experiments confirmed these distinct activation models by monitoring the HCOOH formation. We further evaluated key influencing factors, including Hirshfeld charge and nucleophilicity. Based on our findings, we successfully designed new reactions, demonstrating the practical applications of these mechanisms. This research provides valuable insights into CO₂ conversion strategies, advancing the field of sustainable chemistry.</p>","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":" ","pages":"3011-3021"},"PeriodicalIF":3.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143456288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic Improvement of Mechanical, Creep, and Dimensional Stability in Ultra-Highly Filled Wood Fiber/Polyethylene Composites Using Multimodal Alloy Matrices","authors":"Junjie Xu ,&nbsp;Xiaolong Hao ,&nbsp;Shangkun Huang ,&nbsp;Chuanfu Chen ,&nbsp;Qi Fan ,&nbsp;Lichao Sun ,&nbsp;Rongxian Ou ,&nbsp;Qingwen Wang","doi":"10.1016/j.compositesa.2025.108830","DOIUrl":"10.1016/j.compositesa.2025.108830","url":null,"abstract":"<div><div>Enhancing the mechanical properties and dimensional stability of ultra-highly filled wood-plastic composites (UH-WPCs) presents significant challenges. This study developed UH-WPCs with 70–90 wt% loading using six binary alloy matrices with multimodal and unimodal distributions. FTIR spectroscopy and thermogravimetric analysis revealed an average MAPE esterification rate of 11.9% at 80 wt% loading. Density, morphology, and dynamic mechanical analysis revealed that multimodal high molecular weight alloys significantly improved uniformity and interfacial adhesion compared to unimodal alloys. This increased tensile, flexural, and impact strengths by 30.1%, 22.7%, and 61.8%, respectively, while reducing thermal expansion, creep, and water absorption by 14.0%, 17.1%, and 13.1%. The low molecular weight fraction of multimodal HDPE facilitated miscibility with MAPE, promoted esterification, and minimized fiber damage, while the high molecular weight fraction enhanced composite integrity and cohesiveness. Notably, chain entanglement within the alloy was more critical than esterification rate in improving the mechanical and dimensional stability of UH-WPCs.</div></div>","PeriodicalId":282,"journal":{"name":"Composites Part A: Applied Science and Manufacturing","volume":"193 ","pages":"Article 108830"},"PeriodicalIF":8.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Current State and Ways of Further Improvement of Solar Heat Supply Systems and Their Implementation in the Sharply Continental Climate of Uzbekistan","authors":"Yu. K. Rashidov","doi":"10.3103/S0003701X23602041","DOIUrl":"10.3103/S0003701X23602041","url":null,"abstract":"<p>An analysis of the level of technical solutions for solar heating systems constructed in Uzbekistan was carried out. The importance of organizing statistical monitoring of facilities equipped with such systems in the republic was noted. The introduction of solar power plants in the climatic conditions of Uzbekistan requires solving problems related to protecting solar collectors from freezing of the coolant in winter and boiling in summer, removing dust from glass surfaces, and ensuring effective heat accumulation. However, the technical solutions used to solve these problems in most cases do not meet the basic efficiency and reliability requirements of the building codes and regulations for solar power plants currently in force in the republic. The analysis also took into account the latest scientific achievements aimed at improving the efficiency of solar collectors under real operating conditions. It was noted that during the construction and installation of solar heating systems, in most cases, individual design solutions tailored to each facility’s specific features are not developed; instead, ready-made factory-produced modules are installed. This leads to higher costs for heat storage systems and significant heat losses due to the use of numerous small individual storage tanks, which collectively have a large surface area of heat exchange with the environment. It has been shown that for solar water heaters with a five-section accumulator, heat losses to the environment and material consumption for manufacturing increase by 2 to 2.63 times compared to a compact accumulator with minimal surface area. It is recommended that for solar collectors operating with natural circulation, a five-section accumulator should be considered the maximum permissible configuration for solar water heating systems with horizontal cylindrical accumulators, where the ratio of their dimensions <i>L</i>/<i>D</i> &gt; 1.5.</p>","PeriodicalId":475,"journal":{"name":"Applied Solar Energy","volume":"60 4","pages":"617 - 628"},"PeriodicalIF":1.204,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrochemical [3+3] Annulation of Phenol and Hydrazone: Synthesis of 1,3,4-Oxadiazines.","authors":"Jiahui Zhang, Yangyang Hu, Ya'nan Ran, Huiying Liu, Jingwen Sun, Haijun Wang, Lei Liu","doi":"10.1021/acs.joc.4c02375","DOIUrl":"10.1021/acs.joc.4c02375","url":null,"abstract":"<p><p>A novel [3+3] cyclization reaction between phenol and hydrazone was successfully developed under electrochemically driven conditions. This reaction provided access to a diverse array of 1,3,4-oxadiazinane compounds in consistently high yields, reaching up to 87%. Notably, the reaction exhibited remarkable tolerance toward a broad spectrum of both phenol and hydrazone substrates, underscoring its versatility. Moreover, the protocol distinguished itself by its exceptional atom and step economy, facilitating the efficient construction of functionalized 1,3,4-oxadiazines. The synthetic utility of this approach was further exemplified by its scalability, as demonstrated by gram-scale reactions, and its broad substrate scope.</p>","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":" ","pages":"2869-2878"},"PeriodicalIF":3.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143447368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metallocene Voltammetric Reference Related to a Normal Hydrogen Electrode","authors":"Vlastimil Dorčák, Jan Hrbáč, Jiří Janata, Jan Vacek","doi":"10.1021/acs.jpclett.4c03390","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03390","url":null,"abstract":"The potentials of electrochemical processes in ideal aqueous media are related to the potential of a normal hydrogen electrode (NHE). However, in non-ideal media, the potentials of a metallocene redox couple are used as a reference. Such measurements with free metallocene in solution are complicated by adsorption and mass transport phenomena and solvation effects. Herein, a platinum electrode with an anchored ferrocene moiety (Pt,Fc) was used for cyclic voltammetric measurements of the potential of ferrocene/ferrocenium (Fc/Fc⁺) redox transformation in not only non-aqueous but, for the first time, aqueous solutions as well. This enabled us to eliminate the aforementioned problems associated with the application of free metallocene molecules in solution and, thus, to relate the midpoint potential (<i>E</i>_pm) of the Fc/Fc⁺ redox couple to a NHE. After elimination of the liquid junction potential in an aqueous 0.1 M KCl solution at 25 °C, the average intraday <i>E</i>_pm value obtained with freshly prepared Pt,Fc electrodes was found to be 0.312 ± 0.008 V versus the secondary Ag|AgCl electrode. The Pt,Fc electrode can be applied for the standardization of electrochemical measurements and investigation of solvation phenomena at interfaces in non-ideal media.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"3 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thin Layer Sonoelectrochemistry: The Solvents","authors":"Nadeesha P. W. Rathuwadu, Daniel L. Parr IV, Johna Leddy","doi":"10.1021/acs.jpcc.4c08175","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08175","url":null,"abstract":"In thin layer sonoelectrochemistry (TLS), ultrasound induces constructive interference in a thin fluid layer to increase interfacial rates. In TLS experiments, slow interfacial rates are increased during and after sonication. No cavitation or heating is observed in the fluid. A previously developed model quantifies how solvent properties impact TLS rates. Voltammetry for Fe³⁺ and benzoquinone in tetrahydrofuran, dimethylformamide, water, ethanol, and 2-propanol is undertaken with and without sonication. Rate enhancements vary with solvent properties, as quantitatively predicted by the model. The data vet the TLS model for nonaqueous solvents.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"32 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Manganese(I)-NNSe Pincer Complex Mediated Dehydrogenative Cyclization to Synthesize 2-Aryl-2,3-dihydroquinolin-4(1H)-ones","authors":"Suman Mahala, Sohan Singh, Palak Rakesh, Nattamai Bhuvanesh, Hemant Joshi","doi":"10.1021/acs.joc.4c02731","DOIUrl":"https://doi.org/10.1021/acs.joc.4c02731","url":null,"abstract":"A catalytic one-pot cascade dehydrogenative cyclization of 1-(2-aminophenyl)ethanone using primary alcohols is presented. The reaction is catalyzed by an earth-abundant manganese pincer complex of NNSe ligand, without any solvent, additives, base, or hydrogen acceptor, liberating dihydrogen and water as the only byproducts. Compared to an earlier reported four-step dehydrogenative coupling protocol, only a single step is required to synthesize 2-aryl-2,3-dihydroquinolin-4(1<i>H</i>)-ones.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"210 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Opportunities of applying Large Language Models in building energy sector","authors":"Liang Zhang ,&nbsp;Zhelun Chen","doi":"10.1016/j.rser.2025.115558","DOIUrl":"10.1016/j.rser.2025.115558","url":null,"abstract":"<div><div>In recent years, the rapid advancement and impressive capabilities of Large Language Models have been evident across various engineering domains. This paper explores the application, implications, and potential of Large Language Models in building energy sectors, especially energy efficiency and decarbonization studies, based on an extensive literature review and a survey from building engineers and scientists. The paper explores how LLMs can enhance intelligent control systems, automate code generation for software and modeling tools, optimize data infrastructure, and refine analysis of technical reports and papers. Additionally, the paper discusses the role of LLMs in improving regulatory compliance, supporting building lifecycle management, and revolutionizing education and training practices within the sector. Despite the promising potential of Large Language Models, challenges including complex and expensive computation, data privacy, security and copyright, complexity in fine-tuned Large Language Models, and self-consistency are discussed. The paper concludes with a call for future research focused on the enhancement of LLMs for domain-specific tasks, multi-modal LLMs, and collaborative research between AI and energy experts.</div></div>","PeriodicalId":418,"journal":{"name":"Renewable and Sustainable Energy Reviews","volume":"214 ","pages":"Article 115558"},"PeriodicalIF":16.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}