检索结果-南通市图书馆

Design,Synthesis,and Applications of Mesoporous Covalent Organic Frameworks

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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 threedimensional.Their tunable design and crystalline order endow a range of pore sizes,shapes,functions,and applications that differentiate them from other polymers.The 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 interactions.Their tunability allows for post-modification or the incorporation of additional functional groups for the reinforcement by various noncovalent interactions.The limits of mesoporous COFs are still being investigated,with the design rules continuing to evolve.Here 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

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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 performance.These 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)particles.Reciprocating rolling sphere-on-disk experiments were conducted under electro-tribological loads employing polyurea greases derived from mineral and synthetic base oils with and without additives.Friction 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 grove.Micron-sized pits are formed which contain carbon and oxygen indicating that arcing causes decomposition of the hydrocarbon lubricants.Numerous 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

Conformational dynamics as an intrinsic determinant of prion protein misfolding and neurotoxicity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第10期19卷 2095-2096页

作者： Alessandro Cembran Pedro Fernandez-Funez department of chemistry and biochemistry University of Minnesota DuluthDuluthMNUSA department of Biomedical Sciences University of Minnesota Medical SchoolDuluth CampusDuluthMNUSA

The prion protein(PrP) is the key molecular and pathological mediator of prion diseases,a heterogeneous group of brain disorders with fatal outcomes.Prion diseases are rare but deserve special attention because of their unique familial,sporadic,and transmissible etiologies,all caused by a single agent:misfolded conformations of PrP.

关键词： folding intrinsic dynamics

维普期刊数据库

Increasing polymer scission rate by tying an overhand knot

在线全文

学校读者我要写书评

暂无评论

Science China chemistry 2024年

作者： Yuheng Hu Jennifer T.Ou Jim Y.Huang Yuanning Feng department of chemistry and biochemistry The University of Oklahoma

Similar to the phenomenon of knotted ropes in life, knotted climbing ropes will reduce their strength due to knots. Although computer simulations [1], theoretical speculation[2,3], and intuition [3] suggest that similar processes may occur at the nanoscale, this hypothesis has not been experimentally proven before. With the increasing maturity of molecular recognition and self-assembly, a research communication by Leigh et al. [4]

关键词：

The dual-action mechanism of Arabidopsis cryptochromes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第5期66卷 883-896页

作者： Gao-Ping Qu Bochen Jiang Chentao Lin Basic Forestry and Plant Proteomics Research Center Fujian Agriculture and Forestry UniversityFuzhou 350002China department of chemistry Department of Biochemistry and Molecular BiologyInstitute for Biophysical DynamicsThe University of ChicagoChicagoIL 60637USA

Photoreceptor cryptochromes (CRYs) mediate blue-light regulation of plant growth and development. It has been reported that Arabidopsis CRY1and CRY2 function by physically interacting with at least 84 proteins, including transcription factors or co-factors, chromatin regulators, splicing factors, messenger RNA methyltransferases, DNA repair proteins, E3 ubiquitin ligases, protein kinases and so on. Of these 84 proteins, 47 have been reported to exhibit altered binding affinity to CRYs in response to blue light, and 41 have been shown to exhibit condensation to CRY photobodies. The blue light-regulated composition or condensation of CRY complexes results in changes of gene expression and developmental programs. In this mini-review, we analyzed recent studies of the photoregulatory mechanisms of Arabidopsis CRY complexes and proposed the dual mechanisms of action, including the “Lock-and-Key” and the “Liquid-Liquid Phase Separation (LLPS)” mechanisms. The dual CRY action mechanisms explain, at least partially, the structural diversity of CRY-interacting proteins and the functional diversity of the CRY photoreceptors.

关键词： Arabidopsis blue light cryptochrome CRY1 CRY2 phaseseparation

维普期刊数据库

Charting the course to solid-state dual-ion batteries

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第3期6卷 132-177页

作者： Habtom D.Asfaw Antonia Kotronia Nuria Garcia-Araez Kristina Edström Daniel Brandell department of chemistry Ångström LaboratoryUppsala UniversityUppsalaSweden department of chemistry University of SouthamptonSouthamptonUK

An electrolyte destined for use in a dual-ion battery(DIB)must be stable at the inherently high potential required for anion intercalation in the graphite electrode,while also protecting the Al current collector from anodic dissolution.A higher salt concentration is needed in the electrolyte,in comparison to typical battery electrolytes,to maximize energy density,while ensuring acceptable ionic conductivity and operational safety.In recent years,studies have demonstrated that highly concentrated organic electrolytes,ionic liquids,gel polymer electrolytes(GPEs),ionogels,and water-in-salt electrolytes can potentially be used in DIBs.GPEs can help reduce the use of solvents and thus lead to a substantial change in the Coulombic efficiency,energy density,and long-term cycle life of DIBs.Furthermore,GPEs are suited to manufacture compact DIB designs without separators by virtue of their mechanical strength and electrical performance.In this review,we highlight the latest advances in the application of different electrolytes in DIBs,with particular emphasis on GPEs.

关键词： anion intercalation concentrated electrolytes dual-ion battery graphite ionic liquids polymer electrolyte

Mapping super-resolution image quality

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第2期13卷 178-180页

作者： Megan A.Steves Ke Xu department of chemistry University of CaliforniaBerkeleyCA94720USA

The local quality of super-resolution microscopy images can be assessed and mapped by rolling Fourier ring correlation,even when image quality varies within a single image.

关键词： image resolution Mapping

DPY19L3 promotes vasculogenicmimicry by its C-mannosyltransferase activity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Oncology Research 2024年第4期32卷 607-614页

作者： HASSAN BAYDOUN YUJI KATO HIROKI KAMO ANNA HÜSCH HAYATO MIZUTA RYOTA KAWAHARA SIRO SIMIZU department of Applied chemistry Faculty of Science and TechnologyKeio UniversityYokohama223-8522Japan department of Pharmacy and biochemistry Faculty of ScienceUniversity of TübingenTübingen72074Germany

C-mannosylation is a post-translational modification that occurs intracellularly in the endoplasmic reticulum.In humans,biosynthesis of C-mannosylation in proteins containing thrombospondin type 1 repeat is catalyzed by the DPY19 family;nonetheless,biological functions of protein C-mannosylation are not yet fully understood,especially in tumor progression.Vasculogenic mimicry(VM)is the formation of fluid-conducting channels by highly invasive and genetically deregulated tumor cells,enabling the tumors to form matrix-embedded vasculogenic structures,containing plasma and blood cells to meet the metabolic demands of rapidly growing tumors.In this study,we focused on DPY19L3,a C-mannosyltransferase,and aimed to unravel its role in VM.Knockout of DPY19L3 inhibited the formation of VM in HT1080 human fibrosarcoma cells.Re-expression of wild-type DPY19L3 recovered VM formation;however,DPY19L3 isoform2,an enzymatic activity-defect mutant,did not restore it,suggesting that the C-mannosyltransferase activity of DPY19L3 is crucial to its function.Furthermore,the knockdown of DPY19L3 in MDA-MB-231 breast cancer cells hindered its network formation ability.Altogether,our findings suggest that DPY19L3 is required for VM formation and stipulate the relevance of C-mannosylation in oncogenesis.

关键词： C-mannosylation Vasculogenic mimicry DPY19L3

A New Approach for the Determination of Metronidazole Using Switchable Solvent Coupled with Au-MWCNTs-Modified Electrochemical Sensor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Analysis and Testing 2024年第2期8卷 191-200页

作者： Siamak Kiani Shahvandi Mehrorang Ghaedi Hamid Ahmar chemistry department Yasouj UniversityYasouj75918-74831Iran chemistry department University of ZabolZabol98615-538Iran

In this work,a new liquid-phase microextraction method coupled with an electrochemical technique using a switchable solvent was proposed for the determination of metronidazole.The extraction solvent used was dipropylamine(DPA),which exhibited switchable hydrophilicity.This means that it can become miscible or immiscible when in contact with carboxylic acids in the aqueous sample.The metronidazole was then measured using a glassy carbon electrode that was modified with Au-multiwalled carbon nanotubes(MWCNTs).The eff ect of diff erent parameters such as the type and amount of trigger,the addition of salt,and the volume of extraction solvent on the e fficiency of switchable hydrophilic solvent-based liquid-phase microextraction(SHS-LPME)was investigated using the one-factor-at-a-time method.After optimizing the conditions,the linear calibration curve was obtained in the concentration range of 0.005–250μmol/L.Accordingly,the limit of quantification(LOQ)of 0.005μmol/L and the limit of detection(LOD)of 0.0015μmol/L were obtained,respectively.

关键词： Switchable solvent Metronidazole Liquid-phase microextraction Electrochemical techniques

维普期刊数据库