Faraday Discussions最新文献

{"title":"The detection efficiency of low-dose cryo-4D STEM for biogenic crystals in frozen-hydrated samples","authors":"Lothar Houben, Zohar Eyal and Dvir Gur","doi":"10.1039/D5FD00027K","DOIUrl":"10.1039/D5FD00027K","url":null,"abstract":"<p >Multimodal scanning transmission electron microscopy on vitrified frozen-hydrated specimens promises exceptional spatial resolution into the molecular mechanisms underlying the formation of organic crystals in both health and disease. Detection of crystalline volumes is essential for tracking and mapping nucleation and growth. We provide an analytical description of the low-dose detection limit in diffraction for a thin crystal embedded in a thick matrix, focusing on organic crystals and embedding matrices of low-<em>Z</em> elements such as vitrified ice. Numerical calculations refine our description by accounting for the effects of multiple scattering. Often underestimated, wide-angle tails associated with inelastic scattering play a crucial role for the detection of crystalline reflections in a thick ice matrix, common for cryo-electron microscopy. We show that guanine crystals as thin as a few nanometers can be detected with a fluence of just a few thousand electrons if the ice thickness is below one mean free path for inelastic scattering. The required fluence increases non-linearly with the embedding ice thickness, with a pronounced top–bottom effect regarding the location of the crystal in the sample. Energy-filtered recording significantly reduces the fluence needed for thicker samples. The low-dose simulations implemented here validate the analytical description while acknowledging its limitations due to abstraction from multiple scattering and beam spreading.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"261 ","pages":" 269-285"},"PeriodicalIF":3.1,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/fd/d5fd00027k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144525533","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}

{"title":"Concluding (closing?) remarks","authors":"Félix M. Goñi","doi":"10.1039/D5FD00091B","DOIUrl":"10.1039/D5FD00091B","url":null,"abstract":"<p >This paper summarizes a series of ideas and/or concepts, most of which were the object of the <em>Faraday Discussion</em> on ‘Structural and functional asymmetry of plasma membranes’. A historical review is provided of the early symmetrical and asymmetrical models for membrane structure. Membrane asymmetry in the framework of evolution is suggested as a possible field of study. Functional membrane asymmetry in experimental models is briefly discussed, and the hypothesis that functional asymmetry preceded structural asymmetry in evolution is proposed. Lipid asymmetry and lipid scrambling in bilayers are presented as two complementary aspects of the same process. The use of sphingomyelinases in experimental studies of asymmetry is criticized, due to the lipid scrambling properties of the sphingomyelinase end-product ceramide. The paper ends with a note on the (apparently?) cyclical nature of scientific research.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"259 ","pages":" 634-643"},"PeriodicalIF":3.1,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144641273","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":"Concluding remarks: Faraday Discussions on Advances in supramolecular gels","authors":"Thorfinnur Gunnlaugsson","doi":"10.1039/D5FD00100E","DOIUrl":"10.1039/D5FD00100E","url":null,"abstract":"<p >These concluding remarks summarise the <em>Faraday Discussions</em> that was held in Glasgow, Scotland, on Advances in supramolecular gels, between the 30th of April and the 2nd of May 2025. The meeting was organised by Prof. Dave Adams (University of Glasgow, UK) and Prof. Annela Seddon (University of Bristol, UK) who co-chaired the meeting, in collaboration with the Scientific Committee, Prof. Krishna K. Damodaran (University of Iceland, Iceland), Prof. Demetra Giuri (University of Bologna, Italy) and Prof. Xuehai Yan (Chinese Academy of Science, China). The meeting was organised in four main sections over the four day programme. These were broadly devoted to the characterising (Session 1), using (Session 2), designing (Session 3) of supramolecular gels, and multicomponent gel systems (in Session 4). A lively poster session with range of posters presented mainly by early career, students and postdoctoral fellows, as well as some more established researchers, ran throughout the meeting. The <em>Faraday Discussions</em> programme had contribution talks that highlighted the research area from the design and synthesis of (supramolecular) gels, formed from small organic gelators and bioinspired structures and conjugates, to the different types of characterisation techniques employed for such soft-material research, including the use of rheology, scattering techniques and a variety of imaging platforms, as well as computational studies. This was also completed by the contributions on the applications of functional soft materials with both established and emerging applications. Herein, I will provide a short introductory remark on this fast-growing research field, and a short summary of the work presented within the four sessions, along with the associated discussions that took place. I will then conclude with a brief personal focused discussion of what I consider the main points raised throughout the meeting associated with some of the challenges that this fast-growing research area is facing.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"260 ","pages":" 440-464"},"PeriodicalIF":3.1,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/fd/d5fd00100e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144751892","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}

{"title":"Advanced imaging techniques in biomineralisation research","authors":"Fabio Nudelman and Roland Kröger","doi":"10.1039/D5FD90025E","DOIUrl":"10.1039/D5FD90025E","url":null,"abstract":"<p >A graphical abstract is available for this content</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"261 ","pages":" 9-10"},"PeriodicalIF":3.1,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144323890","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":"List of participants","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144291723","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":"Poster list","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144291724","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":"Crystallisation in biomineral mollusc shell studied by 3D Bragg ptychography","authors":"Tilman A. Grünewald, Peng Li, Julien Duboisset, Julius Nouet, Oier Bikondoa, Jeremie Vidal-Dupiol, Denis Saulnier, Manfred Burghammer and Virginie Chamard","doi":"10.1039/D5FD00020C","DOIUrl":"10.1039/D5FD00020C","url":null,"abstract":"<p >Biomineralisation integrates complex biologically assisted physico-chemical processes leading to an extraordinary diversity of calcareous biomineral crystalline architectures, in intriguing contrast with the consistent presence of a submicrometric granular structure. While the repeated observation of amorphous calcium carbonate is interpreted as a precursor to the crystalline phase, the crystalline transition mechanisms are poorly understood. Access to the crystalline architecture at the mesoscale, <em>i.e.</em>, over a few granules, is key to building realistic crystallisation models. Here we exploit three-dimensional X-ray Bragg ptychography microscopy to provide a series of nanoscale maps of the crystalline structure within the “single-crystalline” prism of the prismatic layer of a <em>Pinctada margaritifera</em> shell. The mesocrystalline organisation exhibits several micrometre-sized iso-oriented/iso-strained crystalline domains, the detailed studies of which reveal the presence of crystalline coherence domains ranging from 130 to 550 nm in size. The further increase in the lattice parameter with the size of the coherence domain likely results from the crystallisation mechanism, pointing towards a maturation process occurring after the initial amorphous-to-crystalline transition.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"261 ","pages":" 192-211"},"PeriodicalIF":3.1,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144232738","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":"Oyster larval biomineralisation – insights from electron backscatter diffraction†","authors":"Kanmani Chandra Rajan, Vengatesen Thiyagarajan, Mohamed Madhar Fazil Sheik Oli, Muthusamy Ayyadurai and Mason N Dean","doi":"10.1039/D5FD00038F","DOIUrl":"10.1039/D5FD00038F","url":null,"abstract":"<p >The initiation of biomineralisation is crucial to the ecology of shelled organisms, for instance providing protection during early life stages when animals are particularly vulnerable. In oysters, the processes involved in early shell deposition remain debated—whether amorphous calcium carbonate (ACC) is deposited initially and transforms into aragonite, or aragonite is directly deposited—largely due to challenges examining the youngest age classes and the limited diversity of model species. Early larval shell deposition has primarily been studied in pearl oysters (<em>Pinctada</em> spp.) due to commercial interests in pearl formation. Edible oyster biomineralisation, however, remains relatively unexplored, despite the commercial importance of post-settlement survival. In this study, we provide a comparative analysis of shell crystallography of a relatively unexamined, ecologically and commercially important edible species, the Hong Kong oyster (<em>Magallana hongkongensis</em>). We focus on three important life stages—D-larvae (3 days post fertilisation), pediveliger (14 days post fertilisation) and spat (three months post settlement)—over which the shell increases drastically in thickness and alters its microstructure. Employing Scanning Electron Microscopy-based Electron BackScatter Diffraction (SEM-EBSD), we show: (1) larval shells are made entirely of aragonite crystals with no traces of ACC detected, whereas spat exhibit calcitic shells; (2) relative to spats, larval shells show a stronger alignment of their crystal <em>c</em>-axes perpendicular to the shell surface, suggesting perhaps a tighter control of mineralisation processes in early life stages; (3) shell grain area increases as the oyster matures, likely linked to the aragonite-to-calcite shift, but also maturation of the larval shell. These quantitative data on ultra- and microstructural changes in oyster shell architecture advance our understanding of early biomineralisation in edible oysters; by elucidating the mechanisms of crystal deposition and organization, we provide a foundation for designing novel materials inspired by natural biomineralisation processes.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"261 ","pages":" 380-395"},"PeriodicalIF":3.1,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144207159","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":"Structure versus composition: a comparative study across scales","authors":"Yannicke Dauphin, Cedrik Lo, Gergely Németh, Christophe Sandt and Jean-Pierre Cuif","doi":"10.1039/D5FD00012B","DOIUrl":"10.1039/D5FD00012B","url":null,"abstract":"<p >Mollusk shells are composed of biominerals. While their mineral polymorphs are limited, their organic components number in the hundreds, if not thousands. Identifying these individual components is only the first step; understanding how they interact to form a shell remains an ongoing challenge. Infrared (IR) spectroscopy is a powerful technique for analyzing the structure and composition of these components while preserving their topographic relationships. This study employed three scales of observation and three samples: <em>Concholepas</em>, <em>Pinctada</em>, and cultivated pearls. Previously available data on their microstructure and compositions were utilized to explore potential correlations with results obtained from various techniques. IR analysis, being non-destructive, facilitates subsequent comparisons with other analytical methods such as Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and X-ray Absorption Near Edge Structure (XANES), thanks to the precise localization of IR data. The findings reveal that data from earlier non-IR analyses align with results from new IR techniques, including Diffuse Reflectance Infrared Fourier Transform (DRIFT), Optical Photothermal Infrared Spectroscopy (O-PTIR), and Scattering-Type Scanning Near-Field Optical Microscopy (sSNOM). This concordance validates the application of these new IR methods for studying biogenic calcium carbonate. Furthermore, the high spatial resolution of O-PTIR and sSNOM enables detailed visualization of structural and compositional features. For instance, the techniques reveal the intricate inner structure of three-month-old pearls, the distribution of proteins, lipids, and sulphated sugars in <em>Concholepas</em>, and the nanoscale differences in the arrangement of nacre and prisms in <em>Pinctada</em>.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"261 ","pages":" 461-483"},"PeriodicalIF":3.1,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/fd/d5fd00012b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144179545","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}

{"title":"Snow and ice: general discussion","authors":"Markus Ammann, Veronica Amoruso, Patrick Ayotte, Thorsten Bartels-Rausch, Hendrik Bluhm, James Brean, Tillmann Buttersack, Lucy J. Carpenter, Rohit Chikkaraddy, Jenée D. Cyran, Bruno Delille, Markus M. Frey, Dwayne Heard, Alexis Lamothe, Kathy S. Law, Jingqiu Mao, Sönke Maus, Jennifer G. Murphy, Peter K. Peterson, Christian Pfrang, Francesca Salteri, Joel Savarino, Jochen Stutz, Céline Toubin, Xin Yang and Paul Zieger","doi":"10.1039/D5FD90015H","DOIUrl":"10.1039/D5FD90015H","url":null,"abstract":"","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 568-596"},"PeriodicalIF":3.4,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144179765","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}