Bimodal endocytic probe for three-dimensional correlative light and electron microscopy.

We present a bimodal endocytic tracer, fluorescent BSA-gold (fBSA-Au), as a fiducial marker for 2D and 3D correlative light and electron microscopy (CLEM) applications. fBSA-Au consists of colloidal gold (Au) particles stabilized with fluorescent BSA. The conjugate is efficiently endocytosed and distributed throughout the 3D endolysosomal network of cells and has an excellent visibility in both fluorescence microscopy (FM) and electron microscopy (EM).

Correlative Organelle Microscopy: Fluorescence Guided Volume Electron Microscopy of Intracellular Processes.

Intracellular processes depend on a strict spatial and temporal organization of proteins and organelles. Therefore, directly linking molecular to nanoscale ultrastructural information is crucial in understanding cellular physiology. Volume or three-dimensional (3D) correlative light and electron microscopy (volume-CLEM) holds unique potential to explore cellular physiology at high-resolution ultrastructural detail across cell volumes.

Evidence of stock connectivity, hybridization, and misidentification in white anglerfish supports the need of a genetics-informed fisheries management framework.

Understanding population connectivity within a species as well as potential interactions with its close relatives is crucial to define management units and to derive efficient management actions. However, although genetics can reveal mismatches between biological and management units and other relevant but hidden information such as species misidentification or hybridization, the uptake of genetic methods by the fisheries management process is far from having been consolidated. Here, we have assessed the power of genetics to better understand the population connectivity of white () and its interaction with its sister species, the black anglerfish ().

3D test sample for the calibration and quality control of stimulated emission depletion (STED) and confocal microscopes.

Multiple samples are required to monitor and optimize the quality and reliability of quantitative measurements of stimulated emission depletion (STED) and confocal microscopes. Here, we present a single sample to calibrate these microscopes, align their laser beams and measure their point spread function (PSF) in 3D. The sample is composed of a refractive index matched colloidal crystal of silica beads with fluorescent and gold cores.

Performance of full scale constructed wetlands in removing antibiotics and antibiotic resistance genes.

Additional treatment of wastewater, such as constructed wetlands (CWs), is a possible solution to reduce the discharge of antibiotics and antibiotic resistance genes (ARGs) from households and industry to the environment. This study aims to investigate the occurrence and removal of antibiotics and ARGs by two full scale CWs operated at different hydraulic retention times (HRT), namely 1 day and 3 days. Both CWs were receiving the same wastewater treatment plant (WWTP) effluent.

On-section correlative light and electron microscopy of large cellular volumes using STEM tomography.

The application of both fluorescence and electron microscopy results in a powerful combination of imaging modalities called "correlative light and electron microscopy" (CLEM). Whereas conventional transmission electron microscopy (TEM) tomography is only able to image sections up to a thickness of ~300nm, scanning transmission electron microscopy (STEM) tomography at 200kV allows the analysis of sections up to a thickness of 900nm in three dimensions. In the current study we have successfully integrated STEM tomography into CLEM as demonstrated for human retinal pigment epithelial 1 (RPE1) cells expressing various fluorescent fusion proteins which were high-pressure frozen and then embedded in Lowicryl HM20.

Seeded Growth Combined with Cation Exchange for the Synthesis of Anisotropic Cu S/ZnS, Cu S, and CuInS Nanorods.

Colloidal copper(I) sulfide (Cu S) nanocrystals (NCs) have attracted much attention for a wide range of applications because of their unique optoelectronic properties, driving scientists to explore the potential of using Cu S NCs as seeds in the synthesis of heteronanocrystals to achieve new multifunctional materials. Herein, we developed a multistep synthesis strategy toward Cu S/ZnS heteronanorods. The Janus-type Cu S/ZnS heteronanorods are obtained by the injection of hexagonal high-chalcocite Cu S seed NCs in a hot zinc oleate solution in the presence of suitable surfactants, 20 s after the injection of sulfur precursors.

Fate of antibiotics and antibiotic resistance genes during conventional and additional treatment technologies in wastewater treatment plants.

Information on the removal of antibiotics and ARGs in full-scale WWTPs (with or without additional treatment technology) is limited. However, it is important to understand the efficiency of full-scale treatment technologies in removing antibiotics and ARGs under a variety of conditions relevant for practice to reduce their environmental spreading. Therefore, this study was performed to evaluate the removal of antibiotics and ARGs in a conventional wastewater treatment plant (WWTP A) and two full-scale combined with additional treatment technologies.

Integrated super resolution fluorescence microscopy and transmission electron microscopy.

In correlative light and electron microscopy (CLEM), the capabilities of fluorescence microscopy (FM) and electron microscopy (EM) are united. FM combines a large field of view with high sensitivity for detecting fluorescence, which makes it an excellent tool for identifying regions of interest. EM has a much smaller field of view but offers superb resolution that allows studying cellular ultrastructure.

Bridging the gap: 3D real-space characterization of colloidal assemblies via FIB-SEM tomography.

Insight in the structure of nanoparticle assemblies up to a single particle level is key to understand the collective properties of these assemblies, which critically depend on the individual particle positions and orientations. However, the characterization of large, micron sized assemblies containing small, 10-500 nanometer, sized colloids is highly challenging and cannot easily be done with the conventional light, electron or X-ray microscopy techniques. Here, we demonstrate that focused ion beam-scanning electron microscopy (FIB-SEM) tomography in combination with image processing enables quantitative real-space studies of ordered and disordered particle assemblies too large for conventional transmission electron tomography, containing particles too small for confocal microscopy.

High accuracy, fiducial marker-based image registration of correlative microscopy images.

Fluorescence microscopy (FM) and electron microscopy (EM) are complementary techniques. FM affords examination of large fields of view and identifying regions of interest but has a low resolution. EM exhibits excellent resolution over a limited field of view.

The 2018 correlative microscopy techniques roadmap.

Developments in microscopy have been instrumental to progress in the life sciences, and many new techniques have been introduced and led to new discoveries throughout the last century. A wide and diverse range of methodologies is now available, including electron microscopy, atomic force microscopy, magnetic resonance imaging, small-angle x-ray scattering and multiple super-resolution fluorescence techniques, and each of these methods provides valuable read-outs to meet the demands set by the samples under study. Yet, the investigation of cell development requires a multi-parametric approach to address both the structure and spatio-temporal organization of organelles, and also the transduction of chemical signals and forces involved in cell-cell interactions.

Towards robust and versatile single nanoparticle fiducial markers for correlative light and electron microscopy.

Fiducial markers are used in correlated light and electron microscopy (CLEM) to enable accurate overlaying of fluorescence and electron microscopy images. Currently used fiducial markers, e.g.

Bottom trawl fishing footprints on the world's continental shelves.

Bottom trawlers land around 19 million tons of fish and invertebrates annually, almost one-quarter of wild marine landings. The extent of bottom trawling footprint (seabed area trawled at least once in a specified region and time period) is often contested but poorly described. We quantify footprints using high-resolution satellite vessel monitoring system (VMS) and logbook data on 24 continental shelves and slopes to 1,000-m depth over at least 2 years.

Fluorescently Labelled Silica Coated Gold Nanoparticles as Fiducial Markers for Correlative Light and Electron Microscopy.

In this work, gold nanoparticles coated with a fluorescently labelled (rhodamine B) silica shell are presented as fiducial markers for correlative light and electron microscopy (CLEM). The synthesis of the particles is optimized to obtain homogeneous, spherical core-shell particles of arbitrary size. Next, particles labelled with different fluorophore densities are characterized to determine under which conditions bright and (photo)stable particles can be obtained.

Size-Dependent Band-Gap and Molar Absorption Coefficients of Colloidal CuInS Quantum Dots.

The knowledge of the quantum dot (QD) concentration in a colloidal suspension and the quantitative understanding of the size-dependence of the band gap of QDs are of crucial importance from both applied and fundamental viewpoints. In this work, we investigate the size-dependence of the optical properties of nearly spherical wurtzite (wz) CuInS (CIS) QDs in the 2.7 to 6.

The Role of a Phonon Bottleneck in Relaxation Processes for Ln-Doped NaYF Nanocrystals.

The localized inner 4f shell transitions of lanthanide ions are largely independent of the local surroundings. The luminescence properties of Ln ions doped into nanocrystals (NCs) are therefore similar to those in bulk crystals. Quantum size effects, responsible for the unique size-dependent luminescence of semiconductor NCs, are generally assumed not to influence the optical properties of Ln-doped insulator NCs.

Incidence, course and risk factors of head injury: a retrospective cohort study.

Objectives: To assess the incidence of head injury and predictors of complication across the care continuum.

Design: Retrospective cohort study using data from a research network. We calculated the incidence of overall head injury in a longitudinal cohort covering 1-year interval (31 369 patient-years), and the incidence of complicated head injury in a longitudinal cohort covering 10 years interval (220 352 patient-ears).

Near-Infrared-Emitting CuInS/ZnS Dot-in-Rod Colloidal Heteronanorods by Seeded Growth.

Synthesis protocols for anisotropic CuInX (X = S, Se, Te)-based heteronanocrystals (HNCs) are scarce due to the difficulty in balancing the reactivities of multiple precursors and the high solid-state diffusion rates of the cations involved in the CuInX lattice. In this work, we report a multistep seeded growth synthesis protocol that yields colloidal wurtzite CuInS/ZnS dot core/rod shell HNCs with photoluminescence in the NIR (∼800 nm). The wurtzite CuInS NCs used as seeds are obtained by topotactic partial Cu for In cation exchange in template CuS NCs.

Single organelle dynamics linked to 3D structure by correlative live-cell imaging and 3D electron microscopy.

Live-cell correlative light-electron microscopy (live-cell-CLEM) integrates live movies with the corresponding electron microscopy (EM) image, but a major challenge is to relate the dynamic characteristics of single organelles to their 3-dimensional (3D) ultrastructure. Here, we introduce focused ion beam scanning electron microscopy (FIB-SEM) in a modular live-cell-CLEM pipeline for a single organelle CLEM. We transfected cells with lysosomal-associated membrane protein 1-green fluorescent protein (LAMP-1-GFP), analyzed the dynamics of individual GFP-positive spots, and correlated these to their corresponding fine-architecture and immediate cellular environment.

Integrated Transmission Electron and Single-Molecule Fluorescence Microscopy Correlates Reactivity with Ultrastructure in a Single Catalyst Particle.

Establishing structure-activity relationships in complex, hierarchically structured nanomaterials, such as fluid catalytic cracking (FCC) catalysts, requires characterization with complementary, correlated analysis techniques. An integrated setup has been developed to perform transmission electron microscopy (TEM) and single-molecule fluorescence (SMF) microscopy on such nanostructured samples. Correlated structure-reactivity information was obtained for 100 nm thin, microtomed sections of a single FCC catalyst particle using this novel SMF-TEM high-resolution combination.

Probing the Influence of Disorder on Lanthanide Luminescence Using Eu-Doped LaPO Nanoparticles.

Lanthanide-doped nanocrystals (NCs) differ from their bulk counterparts due to their large surface to volume ratio. It is generally assumed that the optical properties are not affected by size effects as electronic transitions occur within the well-shielded 4f shell of the lanthanide dopant ions. However, defects and disorder in the surface layer can affect the luminescence properties.

Highly Luminescent Water-Dispersible NIR-Emitting Wurtzite CuInS/ZnS Core/Shell Colloidal Quantum Dots.

Copper indium sulfide (CIS) quantum dots (QDs) are attractive as labels for biomedical imaging, since they have large absorption coefficients across a broad spectral range, size- and composition-tunable photoluminescence from the visible to the near-infrared, and low toxicity. However, the application of NIR-emitting CIS QDs is still hindered by large size and shape dispersions and low photoluminescence quantum yields (PLQYs). In this work, we develop an efficient pathway to synthesize highly luminescent NIR-emitting wurtzite CIS/ZnS QDs, starting from template Cu S nanocrystals (NCs), which are converted by topotactic partial Cu for In exchange into CIS NCs.