The labile forms of elements have been extensively conducted due to their distinctive ecological toxicity and bioavailability. Nevertheless, the selective extraction and in-situ detection of these species from the environment pose significant challenges. In this study, two selective adsorption matrices, thiol-functionalized mesoporous silicon modified polyacrylamide gel (MCM-41-SH-PAM) and polyethyleneimine functionalized polyacrylamide gel (PEI-PAM), were developed as binding phases in diffusive gradients in thin-films technique (DGT) devices for the highly selective extraction of As(III) and As(V), respectively. The results showed that MCM-41-SH-PAM achieves 99.5 % adsorption of As(III) within 12 h with only 0.6 % cross-adsorption of As(V), while PEI-PAM adsorbs over 99.0 % of As(V) within 1 h with merely 3.8 % adsorption of As(III) even after 12 h. The adsorbed As(III) and As(V) can be eluted using 0.5 mol/L HNO3+H2O2 and 0.5 mol/L HNO3 with stable recovery rates of 80 % and 94.5 %, respectively. Combined with precise inductively coupled plasma source mass spectrometer (ICP-MS) detection of the eluent, the method achieves ultra-low detection limits of 0.04 μg/L for As(III) and 0.02 μg/L for As(V), outperforming many conventional speciation analysis techniques. Furthermore, the developed DGT devices demonstrate robust performance across a wide range of environmental conditions and maintain high accuracy in environmental samples, overcoming the limitations of existing methods that are susceptible to matrix interference.

Size-resolved quantification is essential for a comprehensive understanding of the fate, transport, and potential toxicity of nanoplastics in natural waters. However, this has been hindered by the ultralow concentrations of environmental nanoplastics. On-channel preconcentration via asymmetric flow field-flow fractionation (AF4) offers a promising approach to separate and quantify ultratrace environmental nanoplastics with minimal sample disruption. Analytical artifacts that arise when developing size-resolved quantification methods for environmental nanoplastics remain unexplored. Herein, a size-resolved quantification analysis was achieved to determine concentrations of nanoplastics across 20-200 nm under environmentally relevant conditions using AF4-UV. While strong linear correlations were observed between concentration and peak area, the calibration slope exhibited particle dependence for different polystyrene beads, primarily due to their distinct UV absorption coefficients. The limits of detection (LODs) achieved were ∼17 ng (corresponding to 17 μg L-1 for a 1 mL injection volume) in pristine water matrices. However, coenrichment of environmental matrices (e.g., dissolved organic matter) induces severe overloading, elevating LODs in complex matrices (e.g., 25 and 45 ng for bottled drinking water and Yangtze River water samples, respectively). The accumulation of matrix components (e.g., dissolved organic matter, suspended particles) with larger injection volumes exacerbates membrane overloading and reduces recovery rates, thereby elevating the detection threshold for target nanoplastics. Advances in channel dimensions would enable greater particle loading, mitigating matrix overloading, and further reducing LODs. Resolving matrix overloading effects would establish AF4-based methods as a definitive tool for investigating nanoplastic pollution dynamics, bridging the gap for ultralow-concentration monitoring.

Synchrotron radiation can be used as a light source in X-ray microscopy to acquire a high-resolution image of a microscale object for tomography. However, numerous projections must be captured for a high-quality tomographic image to be reconstructed; thus, image acquisition is time consuming. Such dense imaging is not only expensive and time consuming but also results in the target receiving a large dose of radiation. To resolve these problems, sparse acquisition techniques have been proposed; however, the generated images often have many artefacts and are noisy. In this study, a deep-learning-based approach is proposed for the tomographic reconstruction of sparse-view projections that are acquired with a synchrotron light source; this approach proceeds as follows. A convolutional neural network (CNN) is used to first interpolate sparse X-ray projections and then synthesize a sufficiently large set of images to produce a sinogram. After the sinogram is constructed, a second CNN is used for error correction. In experiments, this method successfully produced high-quality tomography images from sparse-view projections for two data sets comprising Drosophila and mouse tomography images. However, the initial results for the smaller mouse data set were poor; therefore, transfer learning was used to apply the Drosophila model to the mouse data set, greatly improving the quality of the reconstructed sinogram. The method could be used to achieve high-quality tomography while reducing the radiation dose to imaging subjects and the imaging time and cost.

Since 2020, synchrotron radiation facilities in several Asia-Pacific countries have been collaborating in a major project called "SYNAPSE" (Synchrotrons for Neuroscience: an Asia-Pacific Scientific Enterprise). They use x-ray imaging to attack in a coordinated fashion one of the major issues in modern science: the structure of animal and human brains, including neurons and connections. The objective is to develop Google-like maps also including detailed structural and functional information for selected regions of interest. The sheer mass of data needed for the objective poses huge problems for the acquisition, processing, storage and use of images. In order to complete the task within a reasonable time, the key element of the SYNAPSE strategy is the parallel and coordinated work of several facilities on the same specimens. This article reviews different aspects of the enterprise, including the foundations of synchrotron radiation, coherence and of its role in advanced imaging, electron accelerators, x-ray optics and detectors. This will provide the foundation for an extensive presentation of the different components of SYNAPSE, with an overview of results already obtained within the consortium.

A temporal focusing multiphoton illumination (TFMI) method is proposed for achieving selective volume illumination (SVI) (i.e., illuminating only the volume of interest) in light-field microscopy (LFM). The proposed method minimizes the background noise of the LFM images and enhances the contrast, and thus improves the imaging quality. Three-dimensional (3D) volumetric imaging is achieved by reconstructing the LFM images using a phase-space deconvolution algorithm. The experimental results obtained using 100-nm fluorescent beads show that the proposed TFMI-LFM system achieves lateral and axial resolutions of 1.2 µm and 1.1 µm, respectively, at the focal plane. Furthermore, the TFMI-LFM system enables 3D images of the single lobe of the drosophila mushroom body with GFP biomarker (OK-107) to be reconstructed in a one-snapshot record.

Microscopy by Achromatic X-rays With Emission of Laminar Light (MAXWELL) is a new X-ray/visible technique with attractive characteristics including isotropic resolution in all directions, large-volume imaging and high throughput. An ultrathin, laminar X-ray beam produced by a Wolter type I mirror irradiates the sample stimulating the emission of visible light by scintillating nanoparticles, captured by an optical system. Three-dimensional (3D) images are obtained by scanning the specimen with respect to the laminar beam. We implemented and tested the technique with a high-brightness undulator at SPring-8, demonstrating its validity for a variety of specimens. This work was performed under the Synchrotrons for Neuroscience-an Asia-Pacific Strategic Enterprise (SYNAPSE) collaboration.

During this global pandemic, cryo-EM has made a great impact on the structure determination of COVID-19 proteins. However, nearly all high-resolution results are based on data acquired on state-of-the-art microscopes where their availability is restricted to a number of centers across the globe with the studies on infectious viruses being further regulated or forbidden. One potential remedy is to employ multipurpose microscopes. Here, we investigated the capability of 200 kV multipurpose microscopes equipped with a direct electron camera in determining the structures of infectious particles. We used 30 nm particles of the grouper nerve necrosis virus as a test sample and obtained the cryo-EM structure with a resolution as high as ∼2.7 Å from a setting that used electron counting. For comparison, we tested a high-end cryo-EM (Talos Arctica) using a similar virus (Macrobrachium rosenbergii nodavirus) to obtain virtually the same resolution. Those results revealed that the resolution is ultimately limited by the depth of field. Our work updates the density maps of these viruses at the sub-3Å level to allow for building accurate atomic models from de novo to provide structural insights into the assembly of the capsids. Importantly, this study demonstrated that multipurpose TEMs are capable of the high-resolution cryo-EM structure determination of infectious particles and is thus germane to the research on pandemics.

Synchrotron radiation evolved over one-half century into a gigantic worldwide enterprise involving tens of thousands of researchers. Initially, almost all users were physicists. But now they belong to a variety of disciplines: chemistry, materials science, the life sciences, medical research, ecology, cultural heritage and others. This poses a challenge: explaining synchrotron sources without requiring a sophisticated background in theoretical physics. Here this challenge is met with an innovative approach that only involves elementary notions, commonly possessed by scientists of all domains.

The new Brain Imaging Beamline (BIB) of the Taiwan Photon Source (TPS) has been commissioned and opened to users. The BIB and in particular its endstation are designed to take advantage of bright unmonochromatized synchrotron X-rays and target fast 3D imaging, ∼1 ms exposure time plus very high ∼0.3 µm spatial resolution. A critical step in achieving the planned performances was the solution to the X-ray induced damaging problems of the detection system. High-energy photons were identified as their principal cause and were solved by combining tailored filters/attenuators and a high-energy cut-off mirror. This enabled the tomography acquisition throughput to reach >1 mm3 min-1, a critical performance for large-animal brain mapping and a vital mission of the beamline.

The high longitudinal and lateral coherence of synchrotron X-rays sources radically transformed radiography. Before them, the image contrast was almost only based on absorption. Coherent synchrotron sources transformed radiography into a multi-faceted tool that can extract information also from “phase” effects. Here, we report a very simple description of the new techniques, presenting them to potential new users without requiring a sophisticated background in advanced physics. We then illustrate the impact of such techniques with a number of examples. Finally, we present the international collaboration SYNAPSE (Synchrotrons for Neuroscience—an Asia-Pacific Strategic Enterprise), which targets the use of phase-contrast radiography to map one full human brain in a few years.

This study employs microstructural and mineralogical characterization to analyze deformation within the Chungliao Tunnel (Formosan Freeway, Taiwan) caused by the movement along the Chishan Fault, as well as its effect on accelerated creep along the fault. The results reveal pyrite-filled fissures and a large amount of wavy extinction quartz and bent muscovite. The mineral particles are fragmented and finely granulated. Additionally, slippage between grains and dislocation creep are observed within Chishan Fault. Therefore, the primary deformation mechanisms of this fault are cracking/frictional sliding, dislocation creep, and grain-boundary sliding. The presence of calcite, clay minerals, physically absorbed water, and crystalline water in the rock enhances fault movement and significantly weakens the strength of rock layers. As a result, the Chungliao Tunnel over the past 18 years has risen at an average annual rate of 8 cm, and is now 130 cm higher than at the time of construction. This study is expected to contribute to future infrastructure planning along the fault. For example, mineral grains in the rock layer tend to align themselves along the fracture orientation, implying the possible stress direction. Moreover, the content of index minerals (e.g. calcite, pyrite, and clay minerals) in the rock layer can be utilized to predict the scale of rock-layer sliding and the severity of potential fault-related disasters.

Synchrotron radiation has emerged over more than one-half century as a gigantic worldwide enterprise involving tens of thousands of researchers. Its history has been continuously and strongly linked to the technical progress of sensors. We review here different aspects of this symbiotic relation, for photon sensors and other devices. We also analyze its probable future developments, specifically in light of the new x-ray free electron lasers.

Xenon, an inert anesthetic gas, is increasingly recognized to possess desirable properties including cytoprotective and anti-inflammatory effects. Here we evaluated the effects of xenon on the progression of lupus nephritis (LN) in a mouse model. A two hour exposure of either 70% xenon or 70% nitrogen balanced with oxygen was administered daily for five weeks to female NZB/W F1 mice that had been induced to develop accelerated and severe LN. Xenon treatment improved kidney function and renal histology, and decreased the renal expression of neutrophil chemoattractants, thereby attenuating glomerular neutrophil infiltration. The effects of xenon were mediated primarily by deceasing serum levels of anti-double stranded DNA autoantibody, inhibiting reactive oxygen species production, NF-κB/NLRP3 inflammasome activation, ICAM-1 expression, glomerular deposition of IgG and C3 and apoptosis, in the kidney; and enhancing renal hypoxia inducible factor 1-α expression. Proteomic analysis revealed that the treatment with xenon downregulated renal NLRP3 inflammasome-mediated cellular signaling. Similarly, xenon was effective in improving renal pathology and function in a spontaneous LN model in female NZB/W F1 mice. Thus, xenon may have a therapeutic role in treating LN but further studies are warranted to determine applicability to patients.

The spatial resolution of x-ray free-electron laser (XFEL) coherent diffraction imaging is currently limited by the fluence of XFELs. Here, we clarify this issue by systematically studying the diffraction with a SPring-8 angstrom compact free electron laser XFEL on gold nanoparticles of size from 10 nm to 80 nm in water solution. The coherent x-ray diffraction patterns obtained from single XFEL pulses were quantitatively analyzed using a small-angle x-ray scattering scheme along with computer simulations. The results show that the detectability of Au nanoparticles can be described by a “master curve” as a function of total electron density, particle size, and x-ray fluence. The difficulty in detecting a small particle under the current XFEL fluence, however, could be largely eliminated by the image enhancement effect through interference from a strong scattering nanoparticle nearby. We investigate this image enhancement effect by quantitatively analyzing the two-particle scattering from Au nanoparticles, and further, applying it to detect a weak biological object of influenza virus with the aid of an Au nanoparticle.

Mapping the large neural networks of animal and human brains is a fundamental but so far elusive task, because of the massive amount of data and the consequent prohibitively long image taking and processing times. We developed an effective strategy called “AXON” (Accelerated X-ray Observation of Neurons) to solve this problem. AXON can achieve comprehensive whole-brain mapping within a reasonable time by combining fast image taking and processing, plus two other critical performances: three-dimensional (3D) imaging with high and isotropic spatial resolution, and multi-scale resolution. We successfully tested this strategy with coordinated experiments at four synchrotron facilities in Japan, Taiwan, Singapore and Korea on two animal models, Drosophila and mouse. Its performances notably allowed full 3D mapping of the Drosophila brain in a few days. With reasonable improvements, AXON can deliver full mapping of large animal and human brains on a realistic time scale of a few years.

The evolution of flight in feathered dinosaurs and early birds over millions of years required flight feathers whose architecture features hierarchical branches. While barb-based feather forms were investigated, feather shafts and vanes are understudied. Here, we take a multi-disciplinary approach to study their molecular control and bio-architectural organizations. In rachidial ridges, epidermal progenitors generate cortex and medullary keratinocytes, guided by Bmp and transforming growth factor β (TGF-β) signaling that convert rachides into adaptable bilayer composite beams. In barb ridges, epidermal progenitors generate cylindrical, plate-, or hooklet-shaped barbule cells that form fluffy branches or pennaceous vanes, mediated by asymmetric cell junction and keratin expression. Transcriptome analyses and functional studies show anterior-posterior Wnt2b signaling within the dermal papilla controls barbule cell fates with spatiotemporal collinearity. Quantitative bio-physical analyses of feathers from birds with different flight characteristics and feathers in Burmese amber reveal how multi-dimensional functionality can be achieved and may inspire future composite material designs.Video Abstract

A transmission X-ray microscope has been designed and commissioned at the 18-ID Full-field X-ray Imaging beamline at the National Synchrotron Light Source II. This instrument operates in the 5-11 keV range, and, with the current set of optics, is capable of 30 nm spatial resolution imaging, with a field of view of about 40 μm. For absorption contrast, the minimum exposure time for a single projection image is about 20 ms and an entire 3D tomography data set can be acquired in under 1 min. The system enables tomographic reconstructions with sub-50 nm spatial resolution without the use of markers on the sample or corrections for rotation run-outs.

Optical super-resolution microscopy allows nanoscale imaging of protein molecules in intact biological tissues. However, it is still challenging to perform large volume super-resolution imaging for entire animal organs. Here we develop a single-wavelength Bessel lightsheet method, optimized for refractive-index matching with clarified specimens to overcome the aberrations encountered in imaging thick tissues. Using spontaneous blinking fluorophores to label proteins of interest, we resolve the morphology of most, if not all, dopaminergic neurons in the whole adult brain (3.64 × 10 7 µm 3 ) of Drosophila melanogaster at the nanometer scale with high imaging speed (436 µm 3 per second) for localization. Quantitative single-molecule localization reveals the subcellular distribution of a monoamine transporter protein in the axons of a single, identified serotonergic Dorsal Paired Medial (DPM) neuron. Large datasets are obtained from imaging one brain per day to provide a robust statistical analysis of these imaging data.