Secondary emission behavior analysis and aerosol characteristics evaluation in laser cutting for safe nuclear decommissioning.

We analyzed secondary emissions and aerosol characteristics generated during the cutting of 10-30 mm thick austenitic 304 L stainless-steel plates with a high-power fiber laser. This study comprehensively includes exhausted aerosols, sedimented dross, wall deposits, and attached slag. The amount of secondary emissions for each cutting process condition was determined by type.

Spectral precision improvement with demagnifying spectral images in spectroscopic nanoscopy.

Spectroscopic nanoscopy (SN) has been recognized as a key functional imaging tool in cell biology and chemistry because it offers the unique capability to simultaneously obtain the spatial and spectral information for single molecules. However, it has an intrinsic issue in using the limited photon budget from single emitters divided into two imaging channels to concurrently acquire spatial and spectral images. Accordingly, this issue lowers the spatial localization and spectral precision.

Switchable and Functional Fluorophores for Multidimensional Single-Molecule Localization Microscopy.

Multidimensional single-molecule localization microscopy (mSMLM) represents a paradigm shift in the realm of super-resolution microscopy techniques. It affords the simultaneous detection of single-molecule spatial locations at the nanoscale and functional information by interrogating the emission properties of switchable fluorophores. The latter is finely tuned to report its local environment through carefully manipulated laser illumination and single-molecule detection strategies.

Design strategy for a dual-wedge prism imaging spectrometer in spectroscopic nanoscopy.

Spectroscopic single-molecule localization microscopy (sSMLM, or spectroscopic nanoscopy) has been established as a key tool in functional super-resolution imaging by providing spatial and spectral information of single molecules at nanoscale resolution. A recently developed dual-wedge prism (DWP) imaging spectrometer, a monolithic optical component, has broadened the accessibility of sSMLM with an improved imaging resolution of more than 40%. It also improved the system reliability by reducing the number of discrete optical components.

Monolithic dual-wedge prism-based spectroscopic single-molecule localization microscopy.

By manipulating the spectral dispersion of detected photons, spectroscopic single-molecule localization microscopy (sSMLM) permits concurrent high-throughput single-molecular spectroscopic analysis and imaging. Despite its promising potential, using discrete optical components and managing the delicate balance between spectral dispersion and spatial localization compromise its performance, including non-uniform spectral dispersion, high transmission loss of grating, high optical alignment demands, and reduced precision. We designed a dual-wedge prism (DWP)-based monolithic imaging spectrometer to overcome these challenges.

Improving spatial precision and field-of-view in wavelength-tagged single-particle tracking using spectroscopic single-molecule localization microscopy.

Spectroscopic single-molecule localization microscopy (sSMLM) generates super-resolution images of single molecules while simultaneously capturing the spectra of their fluorescence emissions. However, sSMLM splits photons from single-molecule emissions into a spatial channel and a spectral channel, reducing both channels' precisions. It is also challenging in transmission grating-based sSMLM to achieve a large field-of-view (FOV) and avoid overlap between the spatial and spectral channels.

Investigating Single-Molecule Fluorescence Spectral Heterogeneity of Rhodamines Using High-Throughput Single-Molecule Spectroscopy.

We experimentally investigated several intramolecular coordinate and environmental changes as potential causes of single-molecule fluorescence spectral heterogeneities (smFSH). We developed a high-throughput single-molecule spectroscopy method to analyze more than 5000 single-molecule emission spectra from each of 9 commonly used fluorophores with different structural rigidities and deposited on substrates with different polarities. We observed an unexpectedly high smFSH from structurally rigid Rhodamine B compared with a structurally flexible Cyanine dye-Alexa Fluor 647.

Sub-10-nm distance measurements between fluorophores using photon-accumulation enhanced reconstruction (PACER).

Single-molecule localization microscopy (SMLM) precisely localizes individual fluorescent molecules within the wide field of view. However, the localization precision is fundamentally limited to around 20 nm due to the physical photon limit of individual stochastic single-molecule emissions. Using spectroscopic SMLM (sSMLM) to resolve their distinct fluorescence emission spectra, we can specifically distinguish and identify individual fluorophore, even the ones of the same type.

Super-resolution imaging of flat-mounted whole mouse cornea.

Super-resolution microscopy revolutionized biomedical research with significantly improved imaging resolution down to the molecular scale. To date, only limited studies reported multi-color super-resolution imaging of thin tissue slices mainly because of unavailable staining protocols and incompatible imaging techniques. Here, we show the first super-resolution imaging of flat-mounted whole mouse cornea using single-molecule localization microscopy (SMLM).

RainbowSTORM: an open-source ImageJ plug-in for spectroscopic single-molecule localization microscopy (sSMLM) data analysis and image reconstruction.

Summary: Spectroscopic single-molecule localization microscopy (sSMLM) simultaneously captures the spatial locations and full spectra of stochastically emitting fluorescent single molecules. It provides an optical platform to develop new multimolecular and functional imaging capabilities. While several open-source software suites provide subdiffraction localization of fluorescent molecules, software suites for spectroscopic analysis of sSMLM data remain unavailable.

Symmetrically dispersed spectroscopic single-molecule localization microscopy.

Spectroscopic single-molecule localization microscopy (sSMLM) was used to achieve simultaneous imaging and spectral analysis of single molecules for the first time. Current sSMLM fundamentally suffers from a reduced photon budget because the photons from individual stochastic emissions are divided into spatial and spectral channels. Therefore, both spatial localization and spectral analysis only use a portion of the total photons, leading to reduced precisions in both channels.

Super-Resolution Imaging of Self-Assembled Nanocarriers Using Quantitative Spectroscopic Analysis for Cluster Extraction.

Self-assembled nanocarriers have inspired a range of applications for bioimaging, diagnostics, and drug delivery. The noninvasive visualization and characterization of these nanocarriers are important to understand their structure to function relationship. However, the quantitative visualization of nanocarriers in the sample's native environment remains challenging with the use of existing technologies.

High-Throughput Single-Molecule Spectroscopy Resolves the Conformational Isomers of BODIPY Chromophores.

A borondipyrromethene (BODIPY) chromophore is connected to a benzoxazole, benzothiazole, or nitrobenzothiazole heterocycle through an olefinic bridge with configuration. Rotation about the two [C-C] bonds flanking the olefinic bridge occurs with fast kinetics in solution, leading to the equilibration of four conformational isomers for each compound. Ensemble spectroscopic measurements in solutions fail to distinguish the coexisting isomers.

Three-dimensional biplane spectroscopic single-molecule localization microscopy.

Spectroscopic single-molecule localization microscopy (sSMLM) captures the full emission spectra of individual molecules while simultaneously localizing their spatial locations at a precision greatly exceeding the optical diffraction limit. To achieve this, sSMLM uses a dispersive optical component to separate the emitted photons into dedicated spatial and spectral imaging channels for simultaneous acquisition. While adding a cylindrical lens in the spatial imaging channel enabled three-dimensional (3D) imaging in sSMLM, the inherent astigmatism leads to technical hurdles in spectral calibration and nonuniform lateral resolution at different depths.

Multicolor super-resolution imaging using spectroscopic single-molecule localization microscopy with optimal spectral dispersion.

We developed transmission diffraction grating-based spectroscopic single-molecule localization microscopy (sSMLM) to collect the spatial and spectral information of single-molecule blinking events concurrently. We characterized the spectral heterogeneities of multiple far-red emitting dyes in a high-throughput manner using sSMLM. We also investigated the influence of spectral dispersion on the single-molecule identification performance of fluorophores with large spectral overlapping.

Theoretical analysis of spectral precision in spectroscopic single-molecule localization microscopy.

Spectroscopic single-molecule localization microscopy (sSMLM) is a novel super-resolution imaging technology, which simultaneously records the nanoscopic location and the corresponding full emission spectrum of every stochastic single-molecule emission event. This spectroscopic imaging capability of sSMLM necessitates the establishment of a theoretical foundation of the newly introduced spectral precision and to guide the system design and optimization. Based on numerical simulation and analytical solution, we introduced such a theoretical model to analyze spectral precision by considering the main system parameters, including signal and background shot noises, readout noise, and the spectral calibration procedure.

Far-Red Photoactivatable BODIPYs for the Super-Resolution Imaging of Live Cells.

The photoinduced disconnection of an oxazine heterocycle from a borondipyrromethene (BODIPY) chromophore activates bright far-red fluorescence. The high brightness of the product and the lack of autofluorescence in this spectral region allow its detection at the single-molecule level within the organelles of live cells. Indeed, these photoactivatable fluorophores localize in lysosomal compartments and remain covalently immobilized within these organelles.

Quantum Beats and Phase Shifts in Two-Dimensional Electronic Spectra of Zinc Naphthalocyanine Monomer and Aggregate.

The origin of quantum coherence in two-dimensional (2D) electronic spectra of molecular aggregates and light-harvesting complexes still remains an open question. In particular, it could be challenging to distinguish between electronic and vibrational coherences for a coupled system, where both degrees of freedom can be simultaneously excited. In this Letter, we examine quantum beats in the 2D spectra of zinc naphthalocyanine (ZnNc) aggregate and monomer, and compare their characteristic features in terms of the frequency and relative phase of diagonal and off-diagonal amplitude oscillations.

Formation and decay of charge carriers in aggregate nanofibers consisting of poly(3-hexylthiophene)-coated gold nanoparticles.

Thin nanofibers (NFs) of J-dominant aggregates with a thickness of 15 nm and thick NFs of H-dominant aggregates with a thickness of 25 nm were fabricated by the self-assembly of poly(3-hexylthiophene)-coated gold nanoparticles. The formation and decay dynamics of the charge carriers, which are dependent on the aggregate types of NFs, was investigated by time-resolved emission and transient-absorption spectroscopy. With increasing excitation energy, the fraction of the fast emission decay component decreased, suggesting that the fast formation of polaron pairs (PP), localized (LP), and delocalized polarons (DP) results from higher singlet exciton states produced by the singlet fusion.