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Making topological protein links using enzymatic reactions

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National Science Review 2024年第3期11卷 50-51页

作者： Roger Castells-Graells Todd O.Yeates department of chemistry and biochemistry University of California UCLA-DOE Institute for Genomics and Proteomics

Proteins are exceedingly complex molecules though, at their heart, they are essentially linear polymers. Pull at their ends and one obtains an extended backbone. While that is true in most cases, some natural proteins... 详细信息

关键词： DESIGN

Decoding the genetic program of micronucleus formation: linking chromosomal instability to human disease

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Signal Transduction and Targeted Therapy 2024年第7期9卷 2840-2842页

作者： Jörg Fahrer Division of food chemistry and Toxicology Department of ChemistryRPTU Kaiserslautern-Landau67663 KaiserslauternGermany

A recent study by Adams and colleagues published in Nature unveiled more than one hundred genes that are involved in micronucleus formation,1 which is a biomarker for genomic instability and associated with aging,cancer,and other disorders.2 As an outstanding achievement,the authors identified DSCC1(DNA Replication And Sister Chromatid Cohesion 1)as a critical gene protecting against early developmental defects,genomic instability,reduced proliferative capacity,cohesinopathy-related phenotypes,and tumor development in vivo.

关键词： chromosomal linking Replication

The influence of various grease compositions and silver nanoparticle additives on electrically induced rolling-element bearing damage

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Friction 2024年第4期12卷 796-811页

作者： Samuel BOND Robert L.JACKSON German MILLS department of chemistry and biochemistry Auburn UniversityAuburn 36849-5412USA department of Mechanical Engineering Auburn UniversityAuburn 36849-5412USA

Leakage currents accelerate surface degradation of metal contacts via small scale arcing across lubricating films,but recent observations suggest that metallic nanoparticle additives in lubricants may be useful to improve contact *** findings prompted a study that examined electrically induced surface pitting of steel contacts in the presence of several lubricating greases including some containing nanometer-sized colloidal silver(Ag)*** rolling sphere-on-disk experiments were conducted under electro-tribological loads employing polyurea greases derived from mineral and synthetic base oils with and without *** forces and electrical resistance were monitored continuously during the tests;surface changes were characterized by means of optical spectroscopy,stylus profilometry,and scanning electron microscopy(SEM)including compositional analysis using energy dispersive spectroscopy(EDS).The observations demonstrate that surface pitting induced by arcing occurs mainly at the points were the rolling motion changes direction and that eroded metal is deposited along the wear ***-sized pits are formed which contain carbon and oxygen indicating that arcing causes decomposition of the hydrocarbon *** findings indicate a significant inhibition of pitting is induced by the Ag nanoparticles;some greases containing other additives exhibit a similar,although less pronounced,effect.

关键词： electric motor bearings wheel bearings electric vehicles arcing electrically induced bearing damage pitting leakage current stray current

Effect of Rosmarinus officinalis and Origanum majorana extracts on stability of sunflower oil during storage and repeated heating

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Oil Crop Science 2024年第1期9卷 29-37页

作者： Ali Sahunie department of Analytical and food chemistry Tishreen UniversityLattakiaSyria

Both rosemary(Rosmarinus officinalis)and marjoram(Origanum majorana)are abundant in phenolic compounds,exhibiting exceptional antioxidant *** study aims to assess the impact of rosemary and marjoram extracts on the stability of sunflower oil during storage and repeated *** oil supplemented with herbal extracts or butylated hydroxytoluene(BHA)at a concentration of 200 ppm was stored for six months under light and dark conditions at room *** value(PV),p-anisidine value(An-V),and total oxidation(TOTOX)value were measured to monitor lipid oxidation progression.A significant difference(P<0.05)was observed between light and dark storage for all studied samples regarding oxidation *** ethanolic extract of rosemary exhibited higher antioxidant activity compared to BHA and other ***,sunflower oil supplemented with the ethanolic extract of rosemary underwent weekly treatment at 100℃for 30 min over four consecutive *** all oxidation indicators increased during repeated heating,the addition of rosemary and marjoram extracts as well as BHA significantly reduced these *** findings demonstrate that both rosemary extracts and marjoram extracts can serve as natural antioxidants in edible oils.

关键词： Phenolic compounds BHA Marjoram extract Rosemary extract Sunflower oil

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Design,Synthesis,and Applications of Mesoporous Covalent Organic Frameworks

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CCS chemistry 2024年第1期6卷 57-68页

作者： Niyati Arora Cassandra Flores Milinda C.Senarathna Christina M.Thompson Ronald A.Smaldone department of chemistry and biochemistry University of TexasDallasRichardsonTexas 75080

Covalent organic frameworks(COFs)are highly ordered and permanently porous organic polymers that can be classified as two-dimensional or *** tunable design and crystalline order endow a range of pore sizes,shapes,functions,and applications that differentiate them from other *** COF pore sizes and shapes rely on the geometry of the monomers and dynamic covalent chemistry,while the stacking of the sheets relies on noncovalent *** tunability allows for post-modification or the incorporation of additional functional groups for the reinforcement by various noncovalent *** limits of mesoporous COFs are still being investigated,with the design rules continuing to *** we report a comprehensive review of mesoporous COFs,explore strategies for large pore reinforcement,highlight structural design and features,elucidate their various functions and applications,discuss fundamental challenges faced that need to be addressed,and predict future directions.

关键词： covalent organic frameworks mesoporous supramolecular chemistry polymers pore size

Fatty acids derived from oviposition systems guide female black soldier flies(Hermetia illucens)toward egg deposition sites

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Insect Science 2024年第4期31卷 1231-1248页

作者： Patrick Klüber Emna Arous Jeanny Jerschow Marco Fraatz Daniel Bakonyi Martin Rühl Holger Zorn department Bioresources Fraunhofer Institute for Molecular Biology and Applied EcologyGiessenGermany Institute of food chemistry and food Biotechnology Justus Liebig University GiessenGiessenGermany

The black soldier fly,Hermetia illucens,comes with big promises for industrial purposes since its larvae feed polyphagously on a broad spectrum of organic ***,research focusing on adult flies is scarce,which is inconsistent with their reproductive relevance within the rearing *** particular,directed oviposition is a challenge in artificial ***,decomposing organic matter is commonly used as oviposition substrate,which has extensive potential for improvement in view of the lack of standardization and the risk of microbial ***,we identified three fatty acids and one fatty acid methyl ester derived from the surface of old oviposition sites and targeted to elucidate their effect on preference behavior and oviposition site selection using Y-olfactometry and prepared oviposition sites,*** to tetradecanoic acid attracted gravid females and stimulated oviposition most strongly,while decanoic acid demonstrated a repulsive *** kept in mixed-sex populations were attracted by tetradecanoic acid,resulting in a higher egg mass found in the compound box(3.0–11.4 fold),a≥2.3 fold reduction of nonspecifically deposited eggs,and the highest total egg ***,decanoic and dodecanoic acid caused females to lay a greater proportion of eggs nonspecifically outside both *** data suggest that fatty acids,especially tetradecanoic acid,are important cues for oviposition site selection in black soldier *** order to achieve a directed oviposition behavior,the role of further short-and long-chain fatty acids as attractants should be examined.

关键词： black soldier fly Hermetia illucens fatty acids insects as food and feed oviposition oviposition site selection tetradecanoic acid

Piling up multidecker pyrgos[n]cages as antibacterial materials

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Science China Materials 2024年

作者： Miguel A.Liuzzi-Vaamonde Jackson B.Lancaster Samantha A.Mason Yuanning Feng department of chemistry and biochemistry The University of Oklahoma

The development of antibiotics is regarded as one of the most significant scientific advances in modern *** the commercialization of antibiotics,infectious diseases were catastrophic throughout history[1].Penicillin was used to treat serious infections in the 1940s,but unfortunately,with the introduction of antibiotics came the emergence of antibiotic resistance[2,3].Evolved and adapted methicillin-resistant Staphylococcus aureus （MRSA） strains are presently impacting community and healthcare systems across the globe[4].

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Stereospecific Assembly of Trisubstituted Alkenes via Photoinduced Nitrogen-Centered Radical-Triggered C—C Bond Cleavage/Functionalization of Oxime Esters

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Chinese Journal of chemistry 2024年第12期42卷 1399-1406页

作者： Yu Bao Zhi-Jie Song Jin-Long Dai Shenghu Yan Yue Zhang Jia-Yin Wang Guigen Li School of Pharmacy Changzhou UniversityChangzhouJiangsu 213164China department of chemistry and biochemistry Texas Tech University79409USA

Comprehensive Summary A general and convenient photoredox-catalyzed acylation and alkylcyanation of MBH acetates has been established,enabling the assembly of the C(sp2)–C(sp3)bond by a nitrogen-centered radical strategy for the synthesis of trisubstituted alkenes in moderate to excellent chemical yields(48 examples in total).The reaction of MBH acetates with acyl(indanone)oxime esters afforded trisubstituted alkenes containing 1,4-dicarbonyl ***,the use of Eosin Y as a photocatalyst in the catalytic system resulted in the formation of distal cyano group-anchored trisubstituted alkenes via deconstructive functionalization of cycloketone oxime ***,these resulting 1,4-dicarbonyl compounds could be applied to late-stage transformations,providing important methods for the synthesis of dihydropyridazin-3(2H)-one.

关键词： Photocatalysis Radical reactions MBH acetates Oxime esters Stereoselectivity Acylation Alkylation Green chemistry

Geometric and defects engineering collaboration for enhanced cascade enzymatic nanoreactors

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Nano Research 2024年第4期17卷 2451-2461页

作者： Zhichao Yu Ruijin Zeng Hexiang Gong Yuan Gao Shuyun Chen Yunsen Wang Dianping Tang Key Laboratory for Analytical Science of food Safety and Biology(MOE&Fujian Province) Department of ChemistryFuzhou UniversityFuzhou 350108China

Highly evolved multi-enzyme cascade catalytic reactions in organisms facilitate rapid transfer of substrates and efficient conversion of intermediates in the catalytic unit,thus rationalizing their efficient *** this study,pore-ordered mesoporous single-atom(Fe)nitrogen-doped carbon nanoreactors(Mp-Fe-CN)were designed,in which a reasonable pore size was designed as a natural enzyme trap coupled to a simulated enzyme center.A polarity-mediated strategy was developed to obtain atomically dispersed nanoporous substrates,with the finding that polarity-guided engineering of the nitrogen-ligand environment and vacancy cluster defects clearly affects nanoporous activity,accompanied by appreciable mesoporous pore size *** active center and distal N atom coordination of Fe-N_(4) affect the catalytic process of the nanozyme exposed by density functional theory(DFT),determining the contribution of hybridized orbitals to electron transfer and the decisive step.A cascade nanoreactor-based domain-limited sarcosine oxidase developed for non-invasive monitoring of sarcosine levels in urine for evaluation of potential prostate carcinogenesis as a proof of *** on the design of surface mesoporous channels of nanocatalytic units,a bridge was built for the interaction between nanozymes and natural enzymes to achieve cascade nanocatalysis of natural enzymatic products.

关键词： nanozyme single-atom catalyst bioreactor cascade catalysis non-Invasive sensing