Imaging techniques

  • Article
    | Open Access

    CPT violation could manifest itself in annihilating positronium events, but searching for this effect would require to know the spin of the annihilating system. Here, the authors do this using a positron-emission tomography scanner, finding no violation with a statistical precision of 10−4.

    • P. Moskal
    • , A. Gajos
    •  & W. Wiślicki
  • Article
    | Open Access

    Bioinspired materials require an understanding of how biomaterials achieve the materials properties. Here, the authors report on the load-bearing shell of Discinisca tenuis and explore how hydration changes the dry shell from hard and stiff to soft and flexible within minutes by reorganisation caused by organic matrix swelling.

    • Johannes Ihli
    • , Anna S. Schenk
    •  & Fabio Nudelman
  • Article
    | Open Access

    The authors introduce an analytical approach for quantitative analysis of 3D atom dynamics during electron microscopy. They image a Co-Mo-S nanocrystal with 1.5 Å resolution, and observe chemical transformations caused by beam-stimulated vibrations.

    • Fu-Rong Chen
    • , Dirk Van Dyck
    •  & Stig Helveg
  • Article
    | Open Access

    Spatiotemporal dynamic of charge carriers is commonly studied with optical or photoconductivity measurements, yet these techniques come with their own limitations. To circumvent these limits, the authors probe the free-carrier diffusion dynamics of microsecond lifetimes via laser-illuminated microwave impedance microscopy.

    • Xuejian Ma
    • , Fei Zhang
    •  & Keji Lai
  • Article
    | Open Access

    The authors demonstrate efficient excitation of nanodiamonds by a focused beam of helium ions, resulting in ionoluminescence. They use this for quantification and correlative localization of single particles within a whole cell at sub-30 nm resolution, and investigate nanodiamond radiosensitisation effects.

    • Zhaohong Mi
    • , Ce-Belle Chen
    •  & Andrew A. Bettiol
  • Article
    | Open Access

    The detailed understanding of the structural variations during cycling in cathodes for Zn-ion aqueous rechargeable batteries is still limited. Here, the authors utilize atomic-column-resolved scanning transmission electron microscopy to elucidate multiphase evolution during hydrated Zn-Ion insertion in vanadium oxide.

    • Pilgyu Byeon
    • , Youngjae Hong
    •  & Sung-Yoon Chung
  • Article
    | Open Access

    Adsorption is a fundamentally important process but challenging to quantify, especially at the nanoscale. Here, the authors map the adsorption affinity and cooperativity of various ligands on single gold nanoparticles and discover adsorption crossover behaviors between different facets, leading to a strategy to control particle shape.

    • Rong Ye
    • , Ming Zhao
    •  & Peng Chen
  • Article
    | Open Access

    The authors present a microwave imaging system that can operate in continuous transmit-receive mode. Using an array of transmitters, a single receiver and a reconstruction matrix that correlate random time patterns with the captured signal, they demonstrate real-time imaging and tracking through a wall.

    • Fabio C. S. da Silva
    • , Anthony B. Kos
    •  & Archita Hati
  • Article
    | Open Access

    Imaging through scattering media is possible using a transmission matrix or the memory effect. Here, the authors describe the nature of optical memory effects in structures of arbitrary geometry and use this framework to estimate the transmission matrix of an optical fibre from just one end.

    • Shuhui Li
    • , Simon A. R. Horsley
    •  & David B. Phillips
  • Article
    | Open Access

    Studying dynamic processes in mechanobiology has been challenging due to lack of appropriate tools. Here, the authors present an interference-based method, illuminated via two rapidly alternating wavelengths, which enables real-time mapping of nanoscale forces with sub-second mechanical fluctuations.

    • Andrew T. Meek
    • , Nils M. Kronenberg
    •  & Malte C. Gather
  • Article
    | Open Access

    Antiferromagnets (AFM) exhibit faster magnetization dynamics, and have immunity to stray fields, making AFMs attractive for spintronic devices. Here, the authors investigate the behaviour of domain walls in AFMs, and find a new type domain wall, a superposition of two adjacent rotational domains.

    • Jonas Spethmann
    • , Martin Grünebohm
    •  & André Kubetzka
  • Article
    | Open Access

    Small-angle X-ray scattering (SAXS) combines the high tissue penetration of X-rays with specificity to periodic nanostructures. The authors use SAXS tensor tomography (SAXS-TT) on intact mouse and human brain tissue samples, to quantify myelin levels and determine myelin integrity, myelinated axon orientation, and fibre tracts non-destructively.

    • Marios Georgiadis
    • , Aileen Schroeter
    •  & Markus Rudin
  • Article
    | Open Access

    Nguyen et al. take a fresh look at Tesla’s concept of an asymmetric fluidic conduit. They show that for alternating flow at high frequencies the device can almost be operated as a diode, enabled by a transition to turbulent-like flow at rather low Reynolds numbers.

    • Quynh M. Nguyen
    • , Joanna Abouezzi
    •  & Leif Ristroph
  • Article
    | Open Access

    The broken-symmetry edge states that are the hallmark of the quantum Hall effect in graphene have eluded spatial measurements. Here, the authors spatially map the quantum Hall broken-symmetry edge states using atomic force microscopy and show a gapped ground state proceeding from the bulk through to the quantum Hall edge boundary.

    • Sungmin Kim
    • , Johannes Schwenk
    •  & Joseph A. Stroscio
  • Article
    | Open Access

    Gamma photons used in positron emission tomography are predicted to be produced in an entangled state. Here, the authors simulate the effects of entanglement and test them through comparison with experimental data from a PET demonstrator apparatus, showing the potential gains in background suppression.

    • D. P. Watts
    • , J. Bordes
    •  & N. A. Zachariou
  • Article
    | Open Access

    Turbulence effects explored use macroscale systems in general. Here the authors generate a turbulent plasma using laser irradiation of a solid target and study the dynamics of the plasma flow at the micron-scale by using scattering of an XFEL beam.

    • G. Rigon
    • , B. Albertazzi
    •  & M. Koenig
  • Article
    | Open Access

    Precise determination of surface atomic structure of metallic nanoparticles is key to unlock their surface/interface properties. Here the authors introduce a neural network-assisted atomic electron tomography approach that provides a three-dimensional reconstruction of metallic nanoparticles at individual atom level.

    • Juhyeok Lee
    • , Chaehwa Jeong
    •  & Yongsoo Yang
  • Article
    | Open Access

    Determining the orientation of nanoscale objects in three-dimensional space has typically required complicated optical setups. Here, the authors develop a simple method to retrieve the 3D orientation of luminescent, lanthanide-doped nanorods from a single-shot emission spectrum.

    • Jeongmo Kim
    • , Reinaldo Chacón
    •  & Thierry Gacoin
  • Article
    | Open Access

    Structured illumination microscopy is usually limited to 2 times spatial resolution improvement over the diffraction limit. Here, the authors introduce a metamaterial structure to generate speckle-like sub-diffraction limit illumination patterns in the near field, and achieve a 7-fold resolution improvement down to 40 nm.

    • Yeon Ui Lee
    • , Junxiang Zhao
    •  & Zhaowei Liu
  • Article
    | Open Access

    Monitoring the nucleation of dendrites in Li-ion batteries during cell cycling is important for the development of new electrochemical materials. Here, the authors use the spectral-spatial mode in electron paramagnetic resonance imaging to visualize the spatial distribution of metallic sub-micrometric lithium structures.

    • Charles-Emmanuel Dutoit
    • , Mingxue Tang
    •  & Elodie Salager
  • Article
    | Open Access

    Monitoring of cerebral function in human neonates remains challenging. Here, the authors propose a bedside monitoring technique using functional ultrasound to identify markers of cerebral activity based on intrinsic functional connectivity for early brain function monitoring.

    • Jerome Baranger
    • , Charlie Demene
    •  & Mickael Tanter
  • Article
    | Open Access

    The obtention and study of actinide elements is challenging due to various factors including their radioactivity and scarcity. Herein, the authors characterize the atomic and electronic structure of Am, Cm, Bk, and Cf compounds using a transmission electron microscopy-based workflow that only requires nanogram amounts of the actinide element.

    • Alexander Müller
    • , Gauthier J.-P. Deblonde
    •  & Andrew M. Minor
  • Article
    | Open Access

    Single-molecule fluorescence currently requires specialized imaging equipment due to the low signal of a single emitter. Here the authors introduce NanoAntennas with Cleared HOtSpots (NACHOS) to boost the signal sufficient for detection of a single emitter by a smartphone, opening the door to point-of-care applications.

    • Kateryna Trofymchuk
    • , Viktorija Glembockyte
    •  & Philip Tinnefeld
  • Article
    | Open Access

    In this manuscript, Finco et al demonstrate the use of a quantum magnetometer based on a single NV centre for all-optical imaging of antiferromagnetic (AFM) spin textures. By exploiting variations of the NV spin relaxation rate, they succeed in imaging AFM domain walls and skyrmions.

    • Aurore Finco
    • , Angela Haykal
    •  & Vincent Jacques
  • Article
    | Open Access

    Spatial differentiation is a form of optical computation which has applications in image processing. Here, the authors exploit nontrivial topological charges in the transfer function to realise broadband isotropic two-dimensional differentiation.

    • Tengfeng Zhu
    • , Cheng Guo
    •  & Shanhui Fan
  • Article
    | Open Access

    Atomic force microscopy (AFM) provides high resolution, but is limited to small areas. Here, the authors introduce a massively parallel AFM approach with >1000 probes in a cantilever-free probe architecture, and present an optical method for detecting probe–sample contact with sub-10 nm vertical precision.

    • Wenhan Cao
    • , Nourin Alsharif
    •  & Keith A. Brown
  • Article
    | Open Access

    Molecular sieving typically occurs when molecules with smaller kinetic diameter than a nanopore selectively enter the pore. Here the authors show, using photoluminescence imaging and ab initio molecular dynamics simulations, that single-walled carbon nanotubes can separate n-hexane from cyclohexane, despite both having larger kinetic diameter than the nanopore.

    • Haoran Qu
    • , Archith Rayabharam
    •  & YuHuang Wang
  • Article
    | Open Access

    High-resolution transmission electron microscopy (HRTEM) has been transformative to the field of polymer science but most HRTEM studies are limited by beam damage on the material. Here, the authors examine the effect of the addition of antioxidants to a series of conjugated polymers and demonstrate minimized beam damage at increased resolution.

    • Brooke Kuei
    •  & Enrique D. Gomez
  • Article
    | Open Access

    Magneto-optic Kerr effect microscopy is useful for dynamic magnetic studies, but is limited by the weak magneto-optical activity. Here, the authors show that extreme anti-reflection result in a Kerr amplitude as large as 20° and enables real-time detection of sub-wavelength magnetic domain reversals.

    • Dongha Kim
    • , Young-Wan Oh
    •  & Min-Kyo Seo
  • Article
    | Open Access

    Non-line-of-sight imaging is typically limited by loss of directional information due to diffuse reflections scattering light in all directions. Here, the authors see around corners by using vertical edges and temporal response to pulsed light to obtain angular and longitudinal resolution, respectively.

    • Joshua Rapp
    • , Charles Saunders
    •  & Vivek K. Goyal
  • Article
    | Open Access

    Study of structural inhomogeneities in zeolites is important but limited by conventional techniques. Here the authors employ in situ free-electron-laser-based time-resolved coherent X-ray diffraction imaging to visualize the effect of these inhomogeneities during catalytic deoxygenation of NOx.

    • Jinback Kang
    • , Jerome Carnis
    •  & Hyunjung Kim
  • Article
    | Open Access

    Here, the authors report on an imaging method based on localized surface plasmon resonance excitation, employing gold nanodisk arrays as substrates that enable imaging of transparent dielectric particles of several sizes. They demonstrate the ability to detect and image particles smaller than the diffraction limit at 25 nm with standard bright-field imaging.

    • Nareg Ohannesian
    • , Ibrahim Misbah
    •  & Wei-Chuan Shih
  • Article
    | Open Access

    Quantifying lipid and water content in tissues non-invasively is difficult, and no method exists to quantify lipids in blood non-invasively. Here the authors develop an imaging approach called shortwave infrared meso-patterned imaging (SWIR-MPI) to detect and spatially map tissue water and lipids in preclinical models.

    • Yanyu Zhao
    • , Anahita Pilvar
    •  & Darren Roblyer
  • Article
    | Open Access

    Existing high-dimensional optical imaging techniques that record space and polarization cannot detect the photon’s time of arrival due to the limited speeds of electronic sensors. Here, the authors develop a single-shot ultrafast imaging modality to record light-speed high-dimensional events with picosecond resolution.

    • Jinyang Liang
    • , Peng Wang
    •  & Lihong V. Wang
  • Article
    | Open Access

    Here, the authors demonstrate a route to high resolution microendoscopy using a multicore fibre with a photonic lantern. They show that distinct multimode patterns of light can be projected from the output of the lantern by individually exciting the single-mode MCF cores, whose patterns are highly stable to fibre movement.

    • Debaditya Choudhury
    • , Duncan K. McNicholl
    •  & Robert R. Thomson
  • Article
    | Open Access

    Three-dimensional imaging of the fetal heart and quantification of blood flow in the surrounding vessels is very challenging because the heart is small and the fetus is free to move in the womb. Here, the authors demonstrate motion-corrected 4D flow MRI of the whole fetal heart and major vessels.

    • Thomas A. Roberts
    • , Joshua F. P. van Amerom
    •  & Joseph V. Hajnal
  • Article
    | Open Access

    Interfacial fluctuations at the nanoscale, such as shape evolution of a growing crystal, are prohibitively difficult to study experimentally. Here, the authors are able to map the kinetic and thermodynamic parameters involved in shaping of nanoparticle supracrystals by directly imaging the fluctuating crystal surface by liquid-phase TEM, and analyzing it in the context of capillary wave theory.

    • Zihao Ou
    • , Lehan Yao
    •  & Qian Chen
  • Article
    | Open Access

    Catalytic selectivity during carbon dioxide electroreduction can be tuned by using geometric copper-based catalysts. Here, the authors use liquid cell transmission electron microscopy to study the in situ synthesis and morphological evolution Cu2O cubes under carbon dioxide electroreduction conditions.

    • Rosa M. Arán-Ais
    • , Rubén Rizo
    •  & Beatriz Roldan Cuenya
  • Article
    | Open Access

    Rational design of multicomponent nanocrystals requires atomic-level understanding of reaction kinetics. Here, the authors apply single-particle liquid-cell electron microscopy imaging coupled with atomistic simulations to understand pathways and rates of bimetallic core-shell nanocubes undergoing oxidative dissolution.

    • Lei Chen
    • , Alberto Leonardi
    •  & Xingchen Ye
  • Article
    | Open Access

    Here, the authors generalize cumulant analysis by extending it into the spectral domain to allow multicolour super-resolution optical fluctuation imaging. The simultaneous acquisition of two spectral channels followed by spectral cross-cumulant analysis and unmixing allows denser spectral and spatial sampling of the super-resolved image.

    • K. S. Grußmayer
    • , S. Geissbuehler
    •  & T. Lasser