The Royal Society of Chemistry最新文献_第10页

NMR and molecular simulation studies on the structure elucidation of the amphotericin B ion channel using ¹³C and ¹⁹F labelling. 利用 13C 和 19F 标记阐明两性霉素 B 离子通道结构的核磁共振和分子模拟研究。

IF 2.9 3区化学

Organic & Biomolecular Chemistry Pub Date : 2024-11-18 DOI: 10.1039/d4ob01468e

Yuichi Umegawa, Hiroshi Tsuchikawa, Wataru Shinoda, Michio Murata

{"title":"NMR and molecular simulation studies on the structure elucidation of the amphotericin B ion channel using 13C and 19F labelling.","authors":"Yuichi Umegawa, Hiroshi Tsuchikawa, Wataru Shinoda, Michio Murata","doi":"10.1039/d4ob01468e","DOIUrl":"https://doi.org/10.1039/d4ob01468e","url":null,"abstract":"Amphotericin B (AmB) has been clinically used for serious fungal infections for over 60 years. The drug is characterized by its specific recognition of ergosterol (Erg) in the fungal cell membrane. AmB and Erg form an ion-channel assembly, which is thought to play a major role in the antibiotic activity of AmB. The precise structure of the ion channel in fungal membranes still remains unelucidated. Recently, the structure of an AmB assembly formed in artificial lipid bilayers was determined using solid-state NMR and molecular dynamics simulations. The structure elucidation was made possible by using 13C- and 19F-labelled AmBs, which were efficiently synthesized using strategies and methods established in previous studies. This review focuses on the structure of the AmB ion channel, which accounts for the antibiotic activity. Additionally, the chemical syntheses of isotope-labelled AmB and Erg used for the structural studies are also reviewed. Solid-state NMR spectra of the labelled AmBs were recorded to measure the distances between labelled sites in the AmB-Erg assembly in lipid bilayers, revealing that the ion channel consisting of seven molecules of AmB spans the bilayer with a single molecule length. Extensive molecular dynamics simulations showed that the conductance of this AmB channel is comparable with those by single-channel recording. The simulations also demonstrated that Erg stabilizes the ion-channel assemblies more efficiently than human cholesterol. The atomic-level structure of the AmB channel in the artificial bilayer will help us to understand the mechanisms of the pharmacological actions and adverse effects of AmB.","PeriodicalId":96,"journal":{"name":"Organic & Biomolecular Chemistry","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142646145","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}

引用次数: 0

The Kondo effect in superparamagnetic 30% Co–Ni/NiO nanocomposites: detailed transport and magnetic investigations 超顺磁性 30% Co-Ni/NiO 纳米复合材料中的 Kondo 效应：详细的传输和磁性研究

IF 3.9 3区化学

RSC Advances Pub Date : 2024-11-18 DOI: 10.1039/D4RA06638C

Shilpa D. Kamble, Charudipa D. Kamble, Umesh P. Gawai, Devendra Kumar, Padmakar G. Chavan and Sanjay K. Gurav

{"title":"The Kondo effect in superparamagnetic 30% Co–Ni/NiO nanocomposites: detailed transport and magnetic investigations","authors":"Shilpa D. Kamble, Charudipa D. Kamble, Umesh P. Gawai, Devendra Kumar, Padmakar G. Chavan and Sanjay K. Gurav","doi":"10.1039/D4RA06638C","DOIUrl":"https://doi.org/10.1039/D4RA06638C","url":null,"abstract":"Nanocomposites of 20% and 30% Co-doped Ni/NiO were synthesized using a microwave-assisted sol–gel auto-combustion method. The 30% Co-doped Ni/NiO nanocomposite exhibited negative magnetoresistance (M-R) at various temperatures, including 2 K, 10 K, 80 K, 100 K, and 250 K. This behavior is interpreted as indicative of a Kondo-like scattering effect. The resistivity ρ(T) upturn observed at low temperatures in the 30% Co-doped Ni/NiO nanocomposite can be accurately described by a power series equation combined with a Kondo term. Furthermore, this sample demonstrated a metal–insulator transition around the Kondo temperature TK ≈ 29.8(5) K, with noticeable resistivity changes at magnetic fields of 0 T, 1 T, 5 T, and 8 T. Additionally, a hump in resistivity at approximately 212 K, 170 K, 243 K, 251 K, and 209 K for magnetic fields of 0 T, 0.05 T, 1 T, 5 T, and 8 T, respectively, is attributed to the charge ordering of Co3+ and Co4+ ions within the Ni/NiO lattice, contributing to a further metal–insulator transition.","PeriodicalId":102,"journal":{"name":"RSC Advances","volume":" 49","pages":" 36667-36674"},"PeriodicalIF":3.9,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ra/d4ra06638c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simple generation of cleavable labels for multiplexed imaging. 简单生成用于多重成像的可裂解标签。

IF 4.3 2区化学

Chemical Communications Pub Date : 2024-11-18 DOI: 10.1039/d4cc01909a

Vincent Van Deuren, Silke Denis, Robin Van den Eynde, Jonathan Sai-Hong Chui, Francesca Bosisio, Frederik De Smet, Wim Dehaen, Wim Vandenberg, Peter Dedecker

引用次数: 0

Cholesterol- and ssDNA-binding fusion protein-mediated DNA tethering on the plasma membrane. 胆固醇和 ssDNA 结合融合蛋白介导的 DNA 在质膜上的系留。

IF 5.8 3区医学

Biomaterials Science Pub Date : 2024-11-18 DOI: 10.1039/d4bm01127a

Kei Nishida, Minon Ishizuka, Eiry Kobatake, Masayasu Mie

{"title":"Cholesterol- and ssDNA-binding fusion protein-mediated DNA tethering on the plasma membrane.","authors":"Kei Nishida, Minon Ishizuka, Eiry Kobatake, Masayasu Mie","doi":"10.1039/d4bm01127a","DOIUrl":"https://doi.org/10.1039/d4bm01127a","url":null,"abstract":"DNA modification of the plasma membrane is an excellent approach for controlling membrane-protein interactions, modulating cell-cell/cell-biomolecule interactions, and extending the biosensing field. The hydrophobic insertion of DNA conjugated with hydrophobic anchoring molecules is utilized for tethering DNA on the cell membrane. In this study, we developed an alternative approach to tether DNA on the plasma membrane based on ssDNA- and cholesterol-binding proteins. We designed a fusion protein (Rep-ALOD4) composed of domain 4 of anthrolysin O (ALOD4), which binds to cholesterol in the plasma membrane, and a replication initiator protein derived from porcine circovirus type 2 (Rep), which forms covalent bonds with single-stranded DNA (ssDNA) with a Rep recognition sequence. Rep-ALOD4 conjugates ssDNA to Rep and binds to the plasma membrane via cholesterol, thus tethering ssDNA to the cells. Quartz crystal microbalance measurements showed that membrane cholesterol binding of Rep-ALOD4 to the lipid bilayer containing cholesterol was accelerated above 20% (w/w) cholesterol in the lipid bilayer. Rep-ALOD4 was conjugated to fluorescein-labeled ssDNA (S-FITC-Rep-ALOD4) and used to treat human cervical tumor HeLa cells. The green signal assigned to S-FITC-Rep-ALOD4 was detected along HeLa cells, whereas diminished by cholesterol removal with methyl β-cyclodextrins. Moreover, ssDNA-conjugated Rep-ALOD4 tethered ssDNA-conjugated functional proteins on the HeLa cell plasma membrane via complementary base pairing. Collectively, Rep-ALOD4 has the potential as an ssDNA-tethering material via plasma membrane cholesterol to extend cell surface engineering.","PeriodicalId":65,"journal":{"name":"Biomaterials Science","volume":" ","pages":""},"PeriodicalIF":5.8,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142646015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The thickness-dependent response of aerosol-jet-printed ultrathin high-aspect-ratio electrochemical microactuators. 气溶胶喷射打印超薄高宽比电化学微执行器的厚度依赖性响应

IF 2.9 3区化学

Soft Matter Pub Date : 2024-11-18 DOI: 10.1039/d4sm00886c

Ji Zhang, Jeremy J Baumberg, Sohini Kar-Narayan

{"title":"The thickness-dependent response of aerosol-jet-printed ultrathin high-aspect-ratio electrochemical microactuators.","authors":"Ji Zhang, Jeremy J Baumberg, Sohini Kar-Narayan","doi":"10.1039/d4sm00886c","DOIUrl":"10.1039/d4sm00886c","url":null,"abstract":"Trilayer electrochemical actuators comprising an electrolyte layer sandwiched between two electrode layers have been shown to exhibit large deformations at low actuation voltages. Here we report the aerosol-jet printing (AJP) of high-aspect-ratio bending-type trilayer electrochemical microactuators comprised of Nafion as the electrolyte and poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS) as the electrode. We investigated how the thicknesses of the electrolyte and electrode layers affect the DC response of these actuators by fabricating high-aspect-ratio trilayer cantilevers with varied layer thicknesses (0.36 μm to 1.9 μm-thick electrodes, and 3.5 μm to 12 μm-thick electrolyte layers). We found that the transported charge and angular deflection are proportional to the applied voltage at steady state, and the charge-to-voltage ratio scales with the PEDOT:PSS thickness. The deflection-to-voltage ratio is found to be strongly affected by the Nafion electrolyte thickness, showing a decreasing trend, but is less affected by the PEDOT:PSS thickness in the range of dimensions fabricated. The timescales for deflection are found to be generally longer than the timescales for charge transfer and no clear trend is observed with respect to layer thicknesses. This work establishes an experimental protocol in geometry optimisation of printed electrochemical microactuators, verifies the applicability of a theoretical model, and lays the groundwork for designing and optimising more sophisticated printed electrochemical microactuation systems.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142646176","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}

引用次数: 0

Tuneable sulfonated hypercrosslinked polymers for selective esterification: insights into performance and stability. 用于选择性酯化的可调磺化超交联聚合物：对性能和稳定性的深入研究。

IF 4.3 2区化学

Chemical Communications Pub Date : 2024-11-18 DOI: 10.1039/d4cc05208k

Paul Schweng, Dorian Guerin-Faucheur, Freddy Kleitz, Robert T Woodward

引用次数: 0

Simple preparation of PVDF composite flexible film with transparent, self-cleaning and radiative cooling properties† 简单制备具有透明、自清洁和辐射冷却特性的 PVDF 复合柔性薄膜†。

IF 3.9 3区化学

RSC Advances Pub Date : 2024-11-18 DOI: 10.1039/D4RA06819J

Junxia Mao, Xinyu Tan, Weiwei Hu, Chao Shi, Fan Zhou and Alkiviadis Tsamis

{"title":"Simple preparation of PVDF composite flexible film with transparent, self-cleaning and radiative cooling properties†","authors":"Junxia Mao, Xinyu Tan, Weiwei Hu, Chao Shi, Fan Zhou and Alkiviadis Tsamis","doi":"10.1039/D4RA06819J","DOIUrl":"https://doi.org/10.1039/D4RA06819J","url":null,"abstract":"Daytime radiative cooling is a technique that relies on reflecting sunlight and radiating heat through mid-infrared wavelengths to cool objects. However, most daytime radiative cooling materials are not transparent, cannot be used for vehicle windows or other objects that need to retain their original color, and are susceptible to rain, dust, and other contamination, resulting in reduced cooling performance. Here, we developed a transparent, self-cleaning, radiative cooling, highly flexible PVDF composite film (PPF film), which was prepared by solvent evaporation phase conversion method and scraping coating method. The preparation method is simple and the material is easy to obtain. The obtained PPF film can be crimped to different degrees, has high flexibility, a transmittance of 94% in the visible light range (380–760 nm), and a water contact angle of 105° and above, and has self-cleaning performance. In the range of 8–13 μm, the average emissivity of the film reached 94.42%. Outdoor experiments show that, on sunny days, the cavity temperature of the device coated with PPF film glass decreases by 5–6 °C compared with that of bare glass, indicating that the PPF film has excellent radiative cooling performance. In addition, it has relatively strong mechanical properties, ultraviolet aging resistance and acid and alkali resistance. The design of the PPF film enables the radiative cooling material to be transparent, self-cleaning and flexible, with broad application prospects in the outer surface of objects requiring light transmission and cooling, such as special-shaped curved surfaces, solar panels, and architectural glass.","PeriodicalId":102,"journal":{"name":"RSC Advances","volume":" 49","pages":" 36656-36666"},"PeriodicalIF":3.9,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ra/d4ra06819j?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Non-communicable diseases: can implementation research change the game for policy and practice? 非传染性疾病：实施研究能否改变政策和实践的游戏规则？

IF 2.7 3区化学

Photochemical & Photobiological Sciences Pub Date : 2024-11-16 Epub Date: 2024-07-01 DOI: 10.1016/S0140-6736(24)01309-6

Kumanan Rasanathan, Phyllis Dako-Gyeke, Wanrudee Isaranuwatchai, Yodi Mahendradhata, Morven Roberts, Giulia Loffreda, Sarah Rylance, Bente Mikkelsen

引用次数: 0

Reduction of hexavalent chromium by compost-derived dissolved organic matter. 堆肥产生的溶解有机物对六价铬的还原作用。

IF 4.3 3区环境科学与生态学

Environmental Science: Processes & Impacts Pub Date : 2024-11-15 DOI: 10.1039/d4em00280f

Chuanghe Miao, Hui Rong, Xiaoqing Wei, Jianying Shang, Hu Zhou, Yizhong Lv

{"title":"Reduction of hexavalent chromium by compost-derived dissolved organic matter.","authors":"Chuanghe Miao, Hui Rong, Xiaoqing Wei, Jianying Shang, Hu Zhou, Yizhong Lv","doi":"10.1039/d4em00280f","DOIUrl":"https://doi.org/10.1039/d4em00280f","url":null,"abstract":"Compost-derived dissolved organic matter (DOMC) is a heterogeneous assemblage of different redox-active organic molecules. We hypothesize that DOMC can interact with Cr(VI) and reduce it to Cr(III), thereby influencing the dynamics of Cr(VI) in soil and aquatic environments. Here, DOMC, along with soil humic substances isolated from red soil and black soil, were fractionated into humic acid fractions (i.e., HAC, HAB, and HAR) and fulvic acid fractions (i.e., FAC, FAB, and FAR), respectively. The reduction and interaction between Cr(VI) and the six organic matter fractions were investigated. The results showed that the total Cr(VI) reduction capacity (TRC) of the six organic matter fractions was 26.77-49.34 μM Cr(VI) per mg OM. The TRC of HA fractions was 35.54-49.34 μM Cr(VI) per mg OM, which exceeded that of FA fractions (26.77-31.29 μM Cr(VI) per mg OM). DOMC had a HA/FA ratio of 0.64, which was higher than that of black soil humic substance (0.59) and red soil humic substance (0.20). The sum of the TRC of DOMC was 35.57 μM Cr(VI) per mg OM, which was larger than that of black soil humic substance (32.87 μM Cr(VI) per mg OM) and red soil humic substance (33.01 μM Cr(VI) per mg OM). The TRC was positively correlated with TOC, TN, phenol C, alkyl C, and aromatic C contents and negatively correlated with E2/E3, O-alkyl C, and carboxyl C contents. The reduction of Cr(VI) at pH 6 was negligible, whereas 32-67% Cr(VI) was reduced at pH 2. The Cr(VI) reduction capacities (RC2, RC2, and RC6) at pH 2-6 were positively correlated (R2 > 0.71) with phenol C. Spectral analysis showed that there was no obvious complexation between Cr(VI) and the six organic matter fractions at pH 6, and thus the reduction of Cr(VI) was negligible, but solution pH could affect the accessibility of organic molecules to Cr(VI) and thus influence Cr(VI) reduction.","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamics of switching processes: general results and applications in intermittent active motion. 切换过程的动力学：间歇性主动运动的一般结果和应用。

IF 2.9 3区化学

Soft Matter Pub Date : 2024-11-15 DOI: 10.1039/d4sm01054j

Ion Santra, Kristian Stølevik Olsen, Deepak Gupta

引用次数: 0