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Time-resolved flow cytometry (TRFC) was used to measure metabolic differences in estrogen receptor-positive breast cancer cells. This specialty cytometry technique measures fluorescence lifetimes as a single-cell parameter thereby providing a unique approach for high-throughput cell counting and screening. Differences in fluorescence lifetime were detected and this was associated with sensitivity to the commonly prescribed therapeutic tamoxifen. Differences in fluorescence lifetime are attributed to the binding states of the autofluorescent metabolite NAD(P)H. The function of NAD(P)H is well described and in general involves cycling from a reduced to oxidized state to facilitate electron transport for the conversion of pyruvate to lactate. NAD(P)H fluorescence lifetimes depend on the bound or unbound state of the metabolite, which also relates to metabolic transitions between oxidative phosphorylation and glycolysis. To determine if fundamental metabolic profiles differ for cells that are sensitive to tamoxifen compared to those that are resistant, large populations of MCF-7 breast cancer cells were screened and fluorescence lifetimes were quantified. Additionally, metabolic differences associated with tamoxifen sensitivity were measured with a Seahorse HS mini metabolic analyzer (Agilent Technologies Inc. Santa Clara, CA) and confocal imaging. Results show that tamoxifen-resistant breast cancer cells have increased utilization of glycolysis for energy production compared to tamoxifen-sensitive breast cancer cells. This work is impacting because it establishes an early step toward developing a reliable screening technology in which large cell censuses can be differentiated for drug sensitivity in a label-free fashion. [ABSTRACT FROM AUTHOR]

This work proposes MP‐Grasp4D (magnetization‐prepared golden‐angle radial sparse parallel 4D) MRI, a free‐breathing, inversion recovery (IR)‐prepared, time‐resolved 4D MRI technique with improved T1‐weighted contrast. MP‐Grasp4D MRI acquisition incorporates IR preparation into a radial gradient echo sequence. MP‐Grasp4D employs a golden‐angle navi‐stack‐of‐stars sampling scheme, where imaging data of rotating radial stacks and navigator stacks (acquired at a consistent rotation angle) are alternately acquired. The navigator stacks are used to estimate a temporal basis for low‐rank subspace‐constrained reconstruction. This allows for the simultaneous capture of both IR‐induced contrast changes and respiratory motion. One temporal frame of the imaging volume in MP‐Grasp4D MRI is reconstructed from a single stack and an adjacent navigator stack on average, resulting in a nominal temporal resolution of 0.16 seconds per volume. Images corresponding to the optimal inversion time (TI) can be retrospectively selected for providing the best image contrast. Reader studies were conducted to assess the performance of MP‐Grasp4D MRI in liver imaging across 30 subjects in comparison with standard Grasp4D MRI without IR preparation. MP‐Grasp4D MRI received significantly higher scores (P < 0.05) than Grasp4D in all assessment categories. There was a moderate to almost perfect agreement (kappa coefficient from 0.42 to 0.9) between the two readers for image quality assessment. When the scan time is reduced, MP‐Grasp4D MRI preserves image contrast and quality, demonstrating additional acceleration capability. MP‐Grasp4D MRI improves T1‐weighted contrast for free‐breathing time‐resolved 4D MRI and eliminates the need for explicit motion compensation. This method is expected to be valuable in different MRI applications such as MR‐guided radiotherapy. [ABSTRACT FROM AUTHOR]

Premise: Plants generate a wide array of signals such as olfactory cues to attract and manipulate the response of pollinators. The present study addresses the temporal patterns of scent emission as an additional dimension to the scent composition. The expectation is that divergent floral function is reflected in divergent qualitative and temporal emission patterns. Methods: We used GC‐ion mobility spectrometry with an integrated pre‐concentration for automated acquisition of the temporal trends in floral volatile emissions for N. viridiflorus, N. papyraceus, and N. cantabricus subsp. foliosus. Results: We found a considerable increase in scent emissions and changes in scent composition for N. viridiflorus at night. This increase was particularly pronounced for aromatic substances such as benzyl acetate and p‐cresol. We found no diurnal patterns in N. papyraceus, despite a similar qualitative composition of floral volatiles. Narcissus cantabricus subsp. foliosus showed no diurnal patterns either and differed considerably in floral scent composition. Conclusions: Scent composition, circadian emission patterns, and floral morphology indicate divergent, but partially overlapping pollinator communities. However, the limited pollinator data from the field only permits a tentative correlation between emission patterns and flower visitors. Narcissus papyraceus and N. cantabricus show no clear diurnal patterns and thus no adjustment to the activity patterns of their diurnal pollinators. In N. viridiflorus, timing of scent emission indicates an adaptation to nocturnal flower visitors, contradicting Macroglossum as the only reported pollinator. We propose that the legitimate pollinators of N. viridiflorus are nocturnal and are still unidentified. [ABSTRACT FROM AUTHOR]

A profound understanding of the binding dynamics of drugs with plasma proteins is highly important as it determines its therapeutical potential. Herein, we have investigated the molecular interaction of Tucatinib (TUC), a novel, primitive and highly selective drug for treatment of HER2+ advanced unresectable breast cancer, with bovine serum albumin (BSA) using multi‐pronged spectroscopic techniques and molecular docking. TUC considerably quenched the intrinsic fluorescence of BSA via static quenching mechanism, and it binds to the hydrophobic cleft of subdomain IIA of BSA with a moderate binding affinity. The thermodynamic analysis revealed the major interplay of van der Waals forces and hydrogen bonding interactions in stabilising the binding. The Förster distance 'r' signifies feasible energy transfer between BSA and TUC. The conformational analyses indicate some alterations in the protein secondary structure as a consequence of some changes in the protein polar environment due to complex formation. The experimental results are supported by docking analyses. [ABSTRACT FROM AUTHOR]

Serial crystallography, born from groundbreaking experiments at the Linac Coherent Light Source in 2009, has evolved into a pivotal technique in structural biology. Initially pioneered at X‐ray free‐electron laser facilities, it has now expanded to synchrotron‐radiation facilities globally, with dedicated experimental stations enhancing its accessibility. This review gives an overview of current developments in serial crystallography, emphasizing recent results in time‐resolved crystallography, and discussing challenges and shortcomings. [ABSTRACT FROM AUTHOR]

Throughout history, the influenza A virus has caused numerous devastating global pandemics. Macrophages, as pivotal innate immune cells, exhibit a wide range of immune functions characterized by distinct polarization states, reflecting their intricate heterogeneity. In this study, we employed the time-resolved single-cell sequencing technique coupled with metabolic RNA labelling to elucidate the dynamic transcriptional changes in distinct polarized states of bone marrow-derived macrophages (BMDMs) upon infection with the influenza A virus. Our approach not only captures the temporal dimension of transcriptional activity, which is lacking in conventional scRNA-seq methods, but also reveals that M2-polarized Arg1_macrophage cluster is the sole state supporting successful replication of influenza A virus. Furthermore, we identified distinct antigen presentation capabilities to CD4+ T and CD8+ T cells across diverse polarized states of macrophages. Notably, the M1 phenotype, exhibited by (BMDMs) and murine alveolar macrophages (AMs), demonstrated superior conventional and cross-presentation abilities for exogenous antigens, with a particular emphasis on cross-presentation capacity. Additionally, as CD8+ T cell differentiation progressed, M1 polarization exhibited an enhanced capacity for cross-presentation. All three phenotypes of BMDMs, including M1, demonstrated robust presentation to CD4+ regulatory T cells, while displaying limited ability to present to naive CD4+ T cells. These findings offer novel insights into the immunological regulatory mechanisms governing distinct polarized states of macrophages, particularly their roles in restricting the replication of influenza A virus and modulating antigen-specific T cell responses through innate immunity.

Understanding the thermoelastic response of a nanostructure is crucial for the choice of materials and interfaces in electronic devices with improved and tailored transport properties at the nanoscale. Here, we show how the deposition of a MoS2 monolayer can strongly modify the nanoscale thermoelastic dynamics of silicon substrates close to their interface. We demonstrate this by creating a transient grating with extreme ultraviolet light, using ultrashort free-electron laser pulses, whose ≈84 nm period is comparable to the size of elements typically used in nanodevices, such as electric contacts and nanowires. The thermoelastic response, featuring coherent acoustic waves and incoherent relaxation, is tangibly modified by the presence of monolayer MoS2. Namely, we observed a major reduction of the amplitude of the surface mode, which is almost suppressed, while the longitudinal mode is basically unperturbed, aside from a faster decay of the acoustic modulations. We interpret this behavior as a selective modification of the surface elasticity, and we discuss the conditions to observe such effect, which may be of immediate relevance for the design of Si-based nanoscale devices. [ABSTRACT FROM AUTHOR]

The binding of drugs to plasma proteins determines its fate within the physiological system, hence profound understanding of its interaction within the bloodstream is important to understand its pharmacodynamics and pharmacokinetics and thereby its therapeutic potential. In this regard, our work delineates the mechanism of interaction of Selumetinib (SEL), a potent anti‐cancer drug showing excellent effect against multiple solid tumors, with plasma protein bovine serum albumin (BSA), using methods such as absorption, steady‐state fluorescence, time‐resolved, fluorescence resonance energy transfer, Fourier transform infrared spectra (FTIR), circular dichroism (CD), synchronous and 3D‐fluorescence, salt fluorescence, molecular docking and molecular dynamic simulations. The BSA fluorescence intensity was quenched with increasing concentration of SEL which indicates interactions of SEL with BSA. Stern–Volmer quenching analysis and lifetime studies indicate the involvement of dynamic quenching. However, some contributions from the static quenching mechanism could not be ruled out unambiguously. The association constant was found to be 5.34 × 105 M−1 and it has a single binding site. The Förster distance (r) indicated probable energy transmission between the BSA and SEL. The positive entropy changes and enthalpy change indicate that the main interacting forces are hydrophobic forces, also evidenced by the results of molecular modeling studies. Conformation change in protein framework was revealed from FTIR, synchronous and 3D fluorescence and CD studies. Competitive binding experiments as well as docking studies suggest that SEL attaches itself to site I (subdomain IIA) of BSA where warfarin binds. Molecular dynamic simulations indicate the stability of the SEL–BSA complex. The association energy between BSA and SEL is affected in the presence of different metals differently. [ABSTRACT FROM AUTHOR]

Due to its strong affinity for chlorine gas, Cd can potentially form CdCl2. Cd-doped CuO thin films are sensitive to chlorine gas, as careful inclusion of Cd in the CuO crystal structure modifies the energy gap depending on the dopant concentration. We employed spray pyrolysis to deposit Cd-doped CuO on fluorine tin oxide (FTO) while heating the substrate to 500 °C. The X-ray diffraction (XRD) analysis revealed that Cd was interstitially incorporated in the CuO lattice structure, as verified by scanning electron microscopy (SEM) imaging. The photoluminescence study demonstrated that increasing the Cd concentration in CuO resulted in higher emission intensity, providing valuable insights into Cu2+ and O2- energy levels. Exposing a Cd-doped CuO thin film to chlorine gas modifies the bandgap, depending on the Cd concentration. The fluctuation in the bandgap energy of copper oxide doped with cadmium indicates the chlorine gas concentration nearby. Time-resolved measurements for the I-V characteristics of the thin film revealed considerable current variation during the exposure to chlorine gas. [ABSTRACT FROM AUTHOR]

Significance: Hyperspectral time-resolved (TR) near-infrared spectroscopy offers the potential to monitor cytochrome-c-oxidase (oxCCO) and blood oxygenation in the adult brain with minimal scalp/skull contamination. We introduce a hyperspectral TR spectrometer that uses compressive sensing to minimize acquisition time without compromising spectral range or resolution and demonstrate oxCCO and blood oxygenation monitoring in deep tissue. Aim: Develop a hyperspectral TR compressive sensing spectrometer and use it to monitor oxCCO and blood oxygenation in deep tissue. Approach: Homogeneous tissue-mimicking phantom experiments were conducted to confirm the spectrometer's sensitivity to oxCCO and blood oxygenation. Twolayer phantoms were used to evaluate the spectrometer's sensitivity to oxCCO and blood oxygenation in the bottom layer through a 10 mm thick static top layer. Results: The spectrometer was sensitive to oxCCO and blood oxygenation changes in the bottom layer of the two-layer phantoms, as confirmed by concomitant measurements acquired directly from the bottom layer. Measures of oxCCO and blood oxygenation by the spectrometer were highly correlated with "gold standard" measures in the homogeneous and two-layer phantom experiments. Conclusions: The results show that the hyperspectral TR compressive sensing spectrometer is sensitive to changes in oxCCO and blood oxygenation in deep tissue through a thick static top layer. [ABSTRACT FROM AUTHOR]

Gas-phase anions present an ideal playground for the exploration of excited-state dynamics. They offer control in terms of the mass, extent of solvation, internal temperature, and conformation. The application of a range of ion sources has opened the field to a vast array of anionic systems whose dynamics are important in areas ranging from biology to star formation. Here, we review recent experimental developments in the field of anion photodynamics, demonstrating the detailed insight into photodynamical and electron-capture processes that can be uncovered. We consider the electronic and nuclear ultrafast dynamics of electronically bound excited states along entire reaction coordinates; electronically unbound states showing that photochemical concepts, such as chromophores and Kasha's rule, are transferable to electron-driven chemistry; and nonvalence states that straddle the interface between bound and unbound states. Finally, we consider likely developments that are sure to keep the field of anion dynamics buoyant and impactful. [ABSTRACT FROM AUTHOR]

Abstract Despite the recent rise of RNA-seq datasets combining single-cell (sc) resolution with 4-thiouridine (4sU) labelling, analytical methods exploiting their power to dissect transcriptional bursting are lacking. Here, we present a mathematical model and Bayesian inference implementation to facilitate genome-wide joint parameter estimation and confidence quantification (R package: burstMCMC). We demonstrate that, unlike conventional scRNA-seq, 4sU scRNA-seq resolves temporal parameters and furthermore boosts inference of dimensionless parameters via a synergy between single-cell resolution and 4sU labelling. We apply our method to published 4sU scRNA-seq data and linked with ChIP-seq data, we uncover previously obscured associations between different parameters and histone modifications.

ABSTRACTOver the last 20 years, XUV and X-ray free-electron lasers have enabled a wide variety of time-resolved experiments that have dramatically advanced our understanding of ultrafast molecular dynamics on atomic length scales and femtosecond time scales. This review focuses on experimental studies of ultrafast dynamics of atoms and molecules in the gas phase, tracing the development of the field from early proof-of-principle studies to recent pump-probe experiments that elucidate the coupled electronic and nuclear dynamics during photochemical reactions with a temporal resolution that is now extending into the attosecond domain.

The L-lactic acid (L-LA) fermentation process, based on sodium hydroxide neutralization, demonstrates environmental friendliness during product extraction. However, lactate fermentation is hindered by the pronounced stress effect of sodium lactate on the strain compared with calcium lactate. In this study, we performed time-resolved transcriptomic and proteomic analyses of Heyndrickxia coagulans DSM1 during NaOH-buffered L-LA production. The expression levels of the glycolytic genes demonstrated an initial increase followed by a subsequent decrease, whereas the tricarboxylic acid cycle genes exhibited an initial decrease followed by a subsequent increase throughout the fermentation process. Moreover, we identified clusters of genes consisting of transcription factors and ATP-binding cassette (ABC) transporters that demonstrate a progressive elevation of expression levels throughout the fermentation process, with significant upregulation observed at later stages. This investigation yields valuable insights into the response mechanisms of H. coagulans during NaOH-buffered L-LA fermentation and presents potential targets for metabolic engineering.

In this study, plasma induced by a nanosecond Nd:YAG laser on thin oil films deposited on a silica wafer was characterized by evaluating the main plasma parameters. Spatially and temporally integrated spectral measurements were performed under experimental conditions optimized for elemental analysis of trace metals in oil. Time-resolved values of the spectral line intensities, electron number density, and plasma temperature were obtained from time-integrated measurements by subtracting averaged spectra recorded at different time delays. The electron number density was estimated using the Stark broadened profile of the hydrogen Balmer alpha line. Ionization temperatures were derived from Mg ionic to atomic line intensity ratios. The obtained apparent values of time-resolved plasma parameters were in the range of 1.1×1017 cm-3 (1.5 μs) to 1.5×1016 cm-3 (4 μs) and 9400 K (3 μs) to 7200 K (5 μs), depending on the delay time. Emission spectra of C2 and CN molecules were used to evaluate the rotational and vibrational temperature.

Demand for low carbon energy storage has highlighted the importance of imaging techniques for the characterization of electrode microstructures to determine key parameters associated with battery manufacture, operation, degradation, and failure both for next generation lithium and other novel battery systems. Here, recent progress and literature highlights from magnetic resonance, neutron, X‐ray, focused ion beam, scanning and transmission electron microscopy are summarized. Two major trends are identified: First, the use of multi‐modal microscopy in a correlative fashion, providing contrast modes spanning length‐ and time‐scales, and second, the application of machine learning to guide data collection and analysis, recognizing the role of these tools in evaluating large data streams from increasingly sophisticated imaging experiments. [ABSTRACT FROM AUTHOR]

X‐ray tomography is a versatile tool in materials research and engineering since it allows for a non‐destructive and three‐dimensional mapping of the constituents of a heterogeneous material as long as they differ in their interactions with X‐rays. Recent developments of the technique have brought down the time needed for the acquisition of a single tomogram by many orders of magnitude compared to what was needed 25 years ago. Nowadays, up to 1000 full tomograms can be recorded in a second, which enables real‐time studies of changes in samples caused by reactions or by applied processing operations. The term tomoscopy has been coined for such sequences of 3D images. We review the application of X‐ray tomography and tomoscopy on metals and describe each step required and the associated challenges. A selection of representative investigations is presented with a focus on time‐resolved phenomena in metals and alloys ranging from mechanical deformation, solidification to metals processing processes such as welding and additive manufacturing. Finally likely future developments are discussed. [ABSTRACT FROM AUTHOR]

In this study, we investigated the enhanced charge transfer (CT) behaviors of single-walled carbon nanotubes (f-SWCNTs) and copper oxide (CuO)-reinforced poly(o-anisidine-co-o-toluidine) nanocomposites. Prior this study, the targeted nanocomposite materials were fabricated using an in situ oxidative polymerization tool. FT-IR, XRD, and SEM techniques were used to confirm the formation of the pure POA-co-POT copolymer and its related nanocomposites in the presence of f-SWCNTs and CuO nanoparticles. The enhancement of the thermal behavior and conductivity in the presence of either f-SWCNTs or f-SWCNTs/CuO confirms the well-dispersed filler on the polymeric matrix. Additionally, steady-state and time-resolved measurements were performed to monitor the influence of f-SWCNTs and CuO on the optical properties and CT related to the copolymerization process. Our fabricated materials showed a quenching of 25% and 31% in the presence of 10% f-SWCNTs, and 2% f-SWCNTs + 15% CuO, respectively. These findings provided strong evidence for the fast charge transfer within the fabricated nanocomposite, which matched the time-resolved results. The fs measurements showed that the ground state bleach (GSB) kinetics was more rapid in the presence of 10% f-SWCNTs compared to that of the free copolymer, while in the presence of 10% CuO, the electron transfer (ET) was faster, which decayed rapidly with a 0.6 ps time constant supporting the metallic nature of the composite. Our findings suggested that the incorporation of f-SWCNTs and CuO into a polymer matrix can close the gap resulting from polymer limitation. [ABSTRACT FROM AUTHOR]

Introduction: This study evaluated our experience with dynamic computed tomography angiography (dCTA) as a diagnostic tool after endovascular aortic aneurysm repair (EVAR) with respect to the endoleak classification and the available literature. Methods: We reviewed all patients who underwent dCTA because of suspected endoleaks after the EVAR and classified the endoleaks in these patients based on standard CTA (sCTA) and dCTA. We systematically reviewed all available publications that investigated the diagnostic accuracy of dCTA compared with other imaging techniques. Results: In our single-center series, 16 dCTAs were performed in 16 patients. In 11 patients, the undefined endoleaks that appeared on sCTA scans were successfully classified using dCTA. In three patients with a type II endoleak and aneurysm sac growth, inflow arteries were successfully identified using dCTA, and in two patients, aneurysm sac growth was observed without a visible endoleak on both sCTA and dCTA scans. The dCTA revealed four occult endoleaks, all of which were type II endoleaks. The systematic review identified six series comparing dCTA with other imaging methods. All articles reported an excellent outcome regarding the endoleak classification. In published dCTA protocols, the number and timing of phases varied greatly, affecting radiation exposure. Time attenuation curves of the current series show that some phases do not contribute to the endoleak classification and that the use of a test bolus improves the timing of the dCTA. Conclusions: The dCTA is a valuable additional tool that can identify and classify endoleaks more accurately than the sCTA. Published dCTA protocols vary greatly and should be optimized to decrease radiation exposure as long as accuracy can be maintained. The use of a test bolus to improve the timing of the dCTA is recommended, but the optimal number of scanning phases is yet to be determined. [ABSTRACT FROM AUTHOR]

Dynamic processes in catalysis are gaining increased attention and could very well be one of the next frontiers in surface science. One way to study such processes is to induce chemical changes on the surface for example by periodically adjusting the (electro)chemical potential in situ and identify the resulting spectral changes. Often this is referred to as Modulation Excitation Spectroscopy (MES). Using Ambient Pressure Photoelectron Spectroscopy data, we here discuss and compare the analysis of MES data using both Phase Sensitive Detection (PSD) and Fourier analysis. We discuss that PSD determines the component magnitude at a user-defined phase value while Fourier analysis provides the maximum oscillation amplitude and respective phase value of oscillating spectral features. We discuss advantages and disadvantages of the different analysis schemes and explore how the full time-evolution can be obtained. [Display omitted] • Phase Sensitive Detection and Fourier analysis are compared for the first time • Pros and cons and limitations of the PSD and Fourier analysis are discussed in detail • Fourier analysis enables on-the-fly detection of oscillating minority species in situ • For the special case of APXPS this enables structure-activity correlation • We hope our work will inspire many future studies of oscillating surface structures [ABSTRACT FROM AUTHOR]

The design and evaluation experiments of a multibeam X-ray tomography optical system that can be used with synchrotron radiation from sources with a narrow energy bandwidth, i.e. undulator sources, are reported. It consists of silicon single crystals that diffract the incident X-rays to 27 beams, which are used to image a sample. The energy of the beams was aligned with an accuracy sufficient for use at typical undulator beamlines. Projection images of a test sample were collected and successfully reconstructed, showing the feasibility of a high-speed X-ray tomography instrument based on the optical system.

Electron spectroscopy with the unprecedented transmission of angle-resolved time-of-flight detection, in combination with pulsed X-ray sources, brings new impetus to functional materials science. We showcase recent developments towards chemical sensitivity from electron spectroscopy for chemical analysis and structural information from photoelectron diffraction using the phase transition properties of 1T-TaS2. Our development platform is the SurfaceDynamics instrument located at the Femtoslicing facility at BESSY II, where femtosecond and picosecond X-ray pulses can be generated and extracted. The scientific potential is put into perspective to the current rapidly developing pulsed X-ray source capabilities from Lasers and Free-Electron Lasers. [ABSTRACT FROM AUTHOR]

The interaction between macromolecular proteins and small molecule ligands is an essential component of cellular function. Such ligands may include enzyme substrates, molecules involved in cellular signalling or pharmaceutical drugs. Together with biophysical techniques used to assess the thermodynamic and kinetic properties of ligand binding to proteins, methodology to determine high-resolution structures that enable atomic level interactions between protein and ligand(s) to be directly visualised is required. Whilst such structural approaches are well established with high throughput X-ray crystallography routinely used in the pharmaceutical sector, they provide only a static view of the complex. Recent advances in X-ray structural biology methods offer several new possibilities that can examine protein-ligand complexes at ambient temperature rather than under cryogenic conditions, enable transient binding sites and interactions to be characterised using time-resolved approaches and combine spectroscopic measurements from the same crystal that the structures themselves are determined. This Perspective reviews several recent developments in these areas and discusses new possibilities for applications of these advanced methodologies to transform our understanding of protein-ligand interactions.

Small-angle X-ray scattering (SAXS) is a method for examining the solution structure, oligomeric state, conformational changes, and flexibility of biomacromolecules at a scale ranging from a few Angstroms to hundreds of nanometers. Wide time scales ranging from real time (milliseconds) to minutes can be also covered by SAXS. With many advantages, SAXS has been extensively used, it is widely used in the structural characterization of biomacromolecules in food science and technology. However, the application of SAXS in charactering the structure of food biomacromolecules has not been reviewed so far. In the current review, the principle, theoretical calculations and modeling programs are summarized, technical advances in the experimental setups and corresponding applications of in situ capabilities: combination of chromatography, time-resolved, temperature, pressure, flow-through are elaborated. Recent applications of SAXS for monitoring structural properties of biomacromolecules in food including protein, carbohydrate and lipid are also highlighted, and limitations and prospects for developing SAXS based on facility upgraded and artificial intelligence to study the structural properties of biomacromolecules are finally discussed. Future research should focus on extending machine time, simplifying SAXS data treatment, optimizing modeling methods in order to achieve an integrated structural biology based on SAXS as a practical tool for investigating the structure-function relationship of biomacromolecules in food industry.

The electrochemistry and photophysics of the Pt(II) complexes [Pt(naphen)(X)] (Hnaphen = naphtho[1,2-b][1,10]phenanthroline, X = Cl or C≡CPh) containing the rigid tridentate C^N^N-coordinating pericyclic naphen ligand was studied alongside the complexes of the tetrahydro-derivative [Pt(thnaphen)(X)] (Hthnaphen = 5,6,8,9-tetrahydro-naphtho[1,2-b][1,10]phenanthroline) and the N^C^N-coordinated complex [Pt(bdq)(Cl)] (Hbdq = benzo[1,2-h:5,4-h']diquinoline. The cyclic voltammetry showed reversible reductions for the C^N^N complexes, with markedly fewer negative potentials (around −1.6 V vs. ferrocene) for the complexes containing the naphen ligand compared with the thnaphen derivatives (around −1.9 V). With irreversible oxidations at around +0.3 V for all of the complexes, the naphen made a difference in the electrochemical gap of about 0.3 eV (1.9 vs. 2.2 eV) compared with thnaphen. The bdq complex was completely different, with an irreversible reduction at around −2 V caused by the N^C^N coordination pattern, which lacked a good electron acceptor such as the phenanthroline unit in the C^N^N ligand naphen. Long-wavelength UV-Vis absorption bands were found around 520 to 530 nm for the C^N^N complexes with the C≡CPh coligand and were red-shifted when compared with the Cl derivatives. The N^C^N-coordinated bdq complex was markedly blue-shifted (493 nm). The steady-state photoluminescence spectra showed poorly structured emission bands peaking at around 630 nm for the two naphen complexes and 570 nm for the thnaphen derivatives. The bdq complex showed a pronounced vibrational structure and an emission maximum at 586 nm. Assuming mixed 3LC/3MLCT excited states, the vibronic progression for the N^C^N bdq complex indicated a higher LC character than assumed for the C^N^N-coordinated naphen and thnaphen complexes. The blue-shift was a result of the different N^C^N vs. C^N^N coordination. The photoluminescence lifetimes and quantum yields ΦL massively increased from solutions at 298 K (0.06 to 0.24) to glassy frozen matrices at 77 K (0.80 to 0.95). The nanosecond time-resolved study on [Pt(naphen)(Cl)] showed a phosphorescence emission signal originating from the mixed 3LC/3MLCT with an emission lifetime of around 3 µs. [ABSTRACT FROM AUTHOR]

An experimental investigation was performed on the wake flow field of an isolated roughness element of a flat plate at Mach 6 by employing the nanoparticle-based planar laser scattering (NPLS) approach. The three-dimensional features and causes of the flow field structure were scrutinized by transient flow field images of roughness elements on various planes. The time-resolved NPLS technique was implemented to examine the time evolution characteristics of the wake flow field of roughness elements. In the following, the process of dynamic evolution of large-scale vortex structures in the wake flow field was methodically assessed. Additionally, the influences of roughness element heights on the wake vortex structure were evaluated and the obtained results were compared. [ABSTRACT FROM AUTHOR]

Enzymes, as a kind of biomacromolecules, play an important role in many physiological processes and relate directly to various diseases. Developing an efficient detection method for enzyme activity is important to achieve early diagnosis of enzyme‐relevant diseases and high throughput screening of potential enzyme‐relevant drugs. Time‐resolved luminescence assay provide a high accuracy and signal‐to‐noise ratios detection methods for enzyme activity, which has been widely used in high throughput screening of enzyme‐relevant drugs and diagnosis of enzyme‐relevant diseases. Inspired by these advantages, various responsive probes based on metal complexes and metal‐free organic compounds have been developed for time‐resolved bioimaging and biosensing of enzyme activity owing to their long luminescence lifetimes, high quantum yields and photostability. In this review, we comprehensively reviewed metal complex‐ and metal‐free organic compound‐based responsive probes applied to detect enzyme activity through time‐resolved imaging, including their design strategies and sensing principles. Current challenges and future prospects in this rapidly growing field are also discussed. [ABSTRACT FROM AUTHOR]

• Synchrotron-based operando APXPS extended to the steady-growth regime of ALD. • Ligand-exchange mechanism in ALD of TiO 2 from TTIP/H 2 O spectroscopically confirmed. • Spectroscopic evidence for a static role of the TiO 2 surface in the TTIP/H 2 O process. Today, atomic layer deposition (ALD) has become a firm corner stone of thin film deposition technology. The microelectronics industry, an early adopter of ALD, imposes stringent requirements on ALD to produce films with highly defined physical and chemical properties, which becomes even more important as device and component dimensions decrease. This, in turn, means that our understanding of the chemical processes underlying ALD needs to increase exponentially. Here, we show that one can use synchrotron-based time-resolved ambient pressure x-ray photoelectron spectroscopy (APXPS) to obtain highly detailed operando information on the surface chemistry of ALD, not only, as proven earlier, during the initial ALD cycles, but also for the steady-growth regime reached during the later stages of deposition. Using event averaging and Fourier-transform methods, we show that the ALD of TiO 2 from titanium tetraisopropoxide (TTIP) and water precursors in the steady-growth regime follows the suggested ligand-exchange reaction mechanism, with no sign of oxygen transport between the deposited layers and the bulk of the film, as has been observed for other materials systems. Hence, the TiO 2 ALD from TTIP and water constitutes a textbook example of metal oxide ALD, as expected for this well-known ALD process. The detailed insight is made possible by computerised control of the precursor pulses that enable the recording of long data sets, which comprise many ALD cycles at highly regular intervals, in combination with an advanced data analysis that allows us to pick out signals undetectable in the raw data. The analysis method also allows to separate oscillating contributions to the signals induced by the ALD pulsing from the overwhelming bulk signal. [Display omitted] [ABSTRACT FROM AUTHOR]

Despite its simplicity, Boltzmann thermometry suffers from limited relative sensitivities since the energy gap must be in the order of magnitude of the thermal energy used for probing. Luminescent crossover thermometry is a potential alternative to exploit high energy gaps at low temperatures based on a generally high non-radiative coupling rate via a configurational crossover. The number of possible candidates for this type of temperature-dependent luminescence is quite versatile. Inorganic systems include transition metal ions with split d orbitals in a ligand field such as Cr3+ and Mn4+, mercury-like s2 ions such as Bi3+ or Pb2+ with coupled 3P0 and 3P1 levels, or lanthanoid ions with low energetic 4fn-15d1 levels next to their 4fn spin-orbit levels. In the case of organic emitters, thermally activated delayed fluorescence (TADF) has become increasingly popular, which relies on thermal coupling between an excited singlet and triplet state via intersystem crossing. While the general concept of two thermally excited radiatively emitting states is valid for each of the mentioned types of luminophores and thus, thermometry is in principle possible, the mechanistic details of the thermal coupling can be different. In this tutorial and theoretically motivated article, I will shortly review the relevant aspects of the excited state kinetics of two thermally coupled levels and demonstrate how the ratio between radiative and intrinsic non-radiative coupling rates affects the possible readout choices for optical signals used as a measure for temperature and how this influences the relative sensitivity of ratiometric and lifetime-based thermometers. An overview over various possible inorganic and organic emitters with the potential for thermometry will be given and based on these kinetic considerations, it will be assessed what readout mode is most recommendable for a given luminescent center.

Dynamical changes in protein structures are essential for protein function and occur over femtoseconds to seconds timescales. X‐ray free electron lasers have facilitated investigations of structural dynamics in proteins with unprecedented temporal and spatial resolution. Light‐activated proteins are attractive targets for time‐resolved structural studies, as the reaction chemistry and associated protein structural changes can be triggered by short laser pulses. Proteins with different light‐absorbing centres have evolved to detect light and harness photon energy to bring about downstream chemical and biological output responses. Following light absorption, rapid chemical/small‐scale structural changes are typically localised around the chromophore. These localised changes are followed by larger structural changes propagated throughout the photoreceptor/photocatalyst that enables the desired chemical and/or biological output response. Time‐resolved serial femtosecond crystallography (SFX) and solution scattering techniques enable direct visualisation of early chemical change in light‐activated proteins on timescales previously inaccessible, whereas scattering gives access to slower timescales associated with more global structural change. Here, we review how advances in time‐resolved SFX and solution scattering techniques have uncovered mechanisms of photochemistry and its coupling to output responses. We also provide a prospective on how these time‐resolved structural approaches might impact on other photoreceptors/photoenzymes that have not yet been studied by these methods. [ABSTRACT FROM AUTHOR]

Considering the crosstalk between the flow and vessel wall, hemodynamic assessment of the neurovascular system may offer a well‐integrated solution for both diagnosis and management by adding prognostic significance to the standard CT/MR angiography. 4D flow MRI or time‐resolved 3D velocity‐encoded phase‐contrast MRI has long been promising for the hemodynamic evaluation of the great vessels, but challenged in clinical studies for assessing intracranial vessels with small diameter due to long scan times and low spatiotemporal resolution. Current accelerated MRI techniques, including parallel imaging with compressed sensing and radial k‐space undersampling acquisitions, have decreased scan times dramatically while preserving spatial resolution. 4D flow MRI visualized and measured 3D complex flow of neurovascular diseases such as aneurysm, arteriovenous shunts, and atherosclerotic stenosis using parameters including flow volume, velocity vector, pressure gradients, and wall shear stress. In addition to the noninvasiveness of the phase contrast technique and retrospective flow measurement through the wanted windows of the analysis plane, 4D flow MRI has shown several advantages over Doppler ultrasound or computational fluid dynamics. The evaluation of the flow status and vessel wall can be performed simultaneously in the same imaging modality. This article is an overview of the recent advances in neurovascular 4D flow MRI techniques and their potential clinical applications in neurovascular disease. Level of Evidence: 5 Technical Efficacy Stage: 3 [ABSTRACT FROM AUTHOR]

Jin Man,1 Jiajia Dong,2 Yilin Wang,1 Leiliang He,1 Songcheng Yu,1 Fei Yu,1 Jia Wang,1 Yongmei Tian,1 Lie Liu,1 Runping Han,2 Hongchao Guo,1 Yongjun Wu,1,3 Lingbo Qu2,4 1College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, People’s Republic of China; 2College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, People’s Republic of China; 3The Key Laboratory of Nanomedicine and Health Inspection of Zhengzhou, Zhengzhou, Henan 450001, People’s Republic of China; 4Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Zhengzhou, Henan 450001, People’s Republic of ChinaCorrespondence: Yongjun WuCollege of Public Health, Zhengzhou University, No.100 Science Avenue, Zhengzhou City 450001, People’s Republic of ChinaTel/Fax +86-371-67781450Email wuyongjun135@126.comLingbo QuCollege of Chemistry, Zhengzhou University, No. 100 Science Avenue, Zhengzhou City 450001, People’s Republic of ChinaTel/Fax +86-371-67781450Email qulingbo@zzu.edu.cnBackground: As two important tumor markers, vascular endothelial growth factor (VEGF) and carcinoembryonic antigen (CEA) have a great value for clinical application in the early diagnosis of cancer. Due to the complex composition of biological samples, the results from combined detection of CEA and VEGF are often taken as a comprehensive indicator in order to make an accurate judgment on a disease. However, most of the current methods can only be used to detect the content of one biomarker. Therefore, it is necessary to explore a simple, rapid, low-cost, and highly sensitive method for the simultaneous detection of CEA and VEGF.Methods: Based on specific aptamers and magnetic separation, a time-resolved chemiluminescence enzyme-linked aptamer assay was developed for the simultaneous detections of CEA and VEGF in serum samples.Results: Under the optimal conditions, the linear range of the calibration curve for VEGF was from 0.5 to 80 ng mL− 1, and the limit of detection was 0.1 ng mL− 1. The linear range of the calibration curve for CEA was 0.5 to 160 ng mL− 1, and the limit of detection was 0.1 ng mL− 1. The established method was applied to detect VEGF and CEA in serum samples. The results were consistent with those of commercial kits.Conclusion: The method has high sensitivity and can quickly obtain accurate results, which could greatly improve the measurement efficiency, reduce the cost, and also reduce the volume of sample consumed. It can be seen that the method established in this study has important application value and broad application prospect in clinical diagnosis.Keywords: chemiluminescence assay, simultaneous detection, vascular endothelial growth factor, time-resolved, carcinoembryonic antigen

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Photosensor proteins are important not only because of their biological functions but also because of their applications in optogenetics. To understand the molecular mechanism behind their biological functions and consequently seek possible applications to optogenetics, the dynamics of their intermolecular interaction (for example, association/dissociation reaction and conformational changes) upon photoexcitation need to be elucidated. Although it has been difficult to trace such reactions in the time domain using traditional spectroscopic techniques, the time-resolved diffusion method based on the transient grating technique has been demonstrated to possess a significant advantage in detecting such spectrally silent dynamics in a time-resolved manner. In this paper, the principle and studies on blue light sensor proteins, phototropins, are described. Reaction kinetics of dimerization, dissociation reactions, and conformational changes were measured, and reaction schemes were determined. This method can be employed to study protein reactions from the viewpoint of diffusion and to elucidate the reaction schemes and kinetics that cannot be detected by other spectroscopic methods. [ABSTRACT FROM AUTHOR]

The time-resolved fluorescence spectroscopy of the C−phycocyanin (C−PC) complex from the cyanobacterium Spirulina platensis (S. platensis) hexamer with the sub-picosecond resolution was detected, and the energy transfer pathways and related transfer rates were identified through the multiexponential analysis based on Monte-Carlo method. With the purpose to construct the relationship between the functions and the structure in vivo, the three−dimension (3D) protein structure was predicted via AlphaFold2, and the arrangement of chromophores treated as the energy transfer nodes were obtained. The experiment results have been matched well with the structure prediction. This work suggests a new way to investigate structure prediction in vivo and the corresponding functions.

Non-destructive testing of low-density and organic foreign bodies is the main challenge for food safety control. Terahertz time-domain spectroscopy (THz-TDS) and imaging technologies were applied to explore the feasibility of detection for insect foreign bodies in the finishing tea products. THz-TDS of tea leaves and foreign bodies of insects demonstrated significant differences in terms of time domain and frequency signals in the range of 0.3–1.0 THz. These signals were corrected by the use of adaptive iteratively reweighted penalized least squares (AirPLS), asymmetric least squares (AsLS), and baseline estimation and de-noising using sparsity (BEADS) for reducing baseline drift and enhancing effective spectral information. The K-nearest neighbor (KNN) and partial least squares discrimination analysis (PLS-DA) models showed the best performance after AirPLS correction with the prediction accuracy of 98 and 100%, respectively. In addition, the locations and outlines of insect bodies could be clearly presented via the THz-TDS image. These results suggested that THz-TDS spectroscopy and imaging provide an alternative tool for the detection of insect foreign bodies in finishing tea products.

Background and Purpose: To determine the feasibility of time-resolved angiography with stochastic trajectories (TWIST) in the diagnosis of spinal dural arteriovenous fistula (SDAVF) and perimedullary arteriovenous fistula (PAVF).Methods: A total of 11 negative patients with TWIST examination were retrospective analyzed and then 18 patients with suspected spinal vascular diseases underwent TWIST. For negative patients, Adamkiewicz artery (AKA), great anterior radiculomedullary vein (GARV) and anterior spinal artery (ASA) were retrospective analyzed. In patients, the results of TWIST were compared with those of DSA.Results: The displaying rates of the ASA, AKA and GARV in 11 negative patients were 100, 90.9, and 90.9%, respectively. The AKA and GARV were separated on TWIST. Of 18 patients, 11 and three were diagnosed with SDAVF and PAVF, respectively. The spinal cord vascular malformation diagnosed on TWIST was consistent with DSA with an excellent intermodality agreement (Kappa = 0.92, p < 0.001). The feeding artery and side of all 11 SDAVF patients were displayed on TWIST and the results were consistent with DSA. For PAVF patients, the feeding artery in two patients and the sides as displayed on TWIST were consistent with DSA.Conclusions: TWIST enables the differentiation of the spinal artery and vein and the differential diagnosis of SDAVF and PAVF.

Background and Purpose: To determine the feasibility of time-resolved angiography with stochastic trajectories (TWIST) in the diagnosis of spinal dural arteriovenous fistula (SDAVF) and perimedullary arteriovenous fistula (PAVF). Methods: A total of 11 negative patients with TWIST examination were retrospective analyzed and then 18 patients with suspected spinal vascular diseases underwent TWIST. For negative patients, Adamkiewicz artery (AKA), great anterior radiculomedullary vein (GARV) and anterior spinal artery (ASA) were retrospective analyzed. In patients, the results of TWIST were compared with those of DSA. Results: The displaying rates of the ASA, AKA and GARV in 11 negative patients were 100, 90.9, and 90.9%, respectively. The AKA and GARV were separated on TWIST. Of 18 patients, 11 and three were diagnosed with SDAVF and PAVF, respectively. The spinal cord vascular malformation diagnosed on TWIST was consistent with DSA with an excellent intermodality agreement (Kappa = 0.92, p < 0.001). The feeding artery and side of all 11 SDAVF patients were displayed on TWIST and the results were consistent with DSA. For PAVF patients, the feeding artery in two patients and the sides as displayed on TWIST were consistent with DSA. Conclusions: TWIST enables the differentiation of the spinal artery and vein and the differential diagnosis of SDAVF and PAVF. [ABSTRACT FROM AUTHOR]

Time-resolved small- and wide-angle X-ray scattering studies of proteins in solution based on the pump-probe approach unveil structural information from intermediates over a broad range of length and time scales. In spite of the promise of this methodology, only a fraction of the wealth of information encoded in scattering data has been extracted in studies performed thus far. Here, we discuss the methodology, summarize results from recent time-resolved X-ray scattering studies, and examine the potential to extract additional information from these scattering curves. [ABSTRACT FROM AUTHOR]

Broadband time-resolved measurements of pristine and Mg-doped vanadium dioxide (VO2) films are presented herein. The two films were synthesized on float glass and K-glass (SnO2 coated) substrates, respectively. Spectral and temporal dynamics of the insulator to metal transition are accessed via femtosecond pump-probe spectroscopy. Reflection and transmission signals were recorded during sample perturbation by high photon energy, 3.1 eV, laser pulses for below and above the transition threshold values of the excitation fluence. Changes of the spectral dynamics due to photoexcitation are tracked throughout the visible spectrum by use of broadband white-light supercontinuum pulses. The study demonstrates a faster temporal response of the Mg-doped film across the probed spectrum. The system is photoexcited to the metallic state reaching a plateau value in signal transmission within less than 5 ps post-pulse perturbation. These optimized trends of the Mg-doped VO2 films hold promise for applications necessitating ultrafast optical switching capabilities. [ABSTRACT FROM AUTHOR]

Time‐resolved cryo‐electron microscopy (TrEM) allows the study of proteins under non‐equilibrium conditions on the millisecond timescale, permitting the analysis of large‐scale conformational changes or assembly and disassembly processes. However, the technique is developing and there have been few comparisons with other biochemical kinetic studies. Using current methods, the shortest time delay is on the millisecond timescale (∼5–10 ms), given by the delay between sample application and vitrification, and generating longer time points requires additional approaches such as using a longer delay line between the mixing element and nozzle, or an incubation step on the grid. To compare approaches, the reaction of ATP with the skeletal actomyosin S1 complex was followed on grids prepared with a 7–700 ms delay between mixing and vitrification. Classification of the cryo‐EM data allows kinetic information to be derived which agrees with previous biochemical measurements, showing fast dissociation, low occupancy during steady‐state hydrolysis and rebinding once ATP has been hydrolysed. However, this rebinding effect is much less pronounced when on‐grid mixing is used and may be influenced by interactions with the air–water interface. Moreover, in‐flow mixing results in a broader distribution of reaction times due to the range of velocities in a laminar flow profile (temporal spread), especially for longer time delays. This work shows the potential of TrEM, but also highlights challenges and opportunities for further development. [ABSTRACT FROM AUTHOR]

The photoacoustic effect was explained more than half a century ago and has since been used to develop non-destructive and non-contact techniques for testing materials. Most existing experimental setups are time-consuming. In this paper, we deal with the development of time-resolved photoacoustics to use all the advantages of photoacoustic techniques in the development of real-time characterization of various samples. We propose a model for a time-resolved photoacoustic signal of thin samples measured in a gas-microphone setup with a minimal volume cell, assuming that the gas column in the cell can be shorter than the thermal diffusion length in air. The derived model additionally includes the influence of thermal relaxations and detector transfer function. We also suggest a methodology for inverse problem solving, i.e., to determine the sample properties from measured signals using the presented model. The model has been validated by comparing the model predictions with an experimentally measured signal for a thin metallic sample excited by an optical pulse train of a repetition rate of 12 Hz. The results obtained by the suggested inverse-problem solving methodology are in accordance with the literature, thus confirming the validity of the proposed methodology. We have shown that the proposed model and the methodology of inverse time-resolved photoacoustic problems give the same results as the widespread time-consuming frequency photoacoustic measurements. This means that the presented model and methodology enable the employment of low-frequency time-resolved gas-microphone photoacoustics in the real-time characterization of thin solids. [ABSTRACT FROM AUTHOR]

An experimental investigation was performed on the wake flow field of an isolated roughness element of a flat plate at Mach 6 by employing the nanoparticle-based planar laser scattering (NPLS) approach. The three-dimensional features and causes of the flow field structure were scrutinized by transient flow field images of roughness elements on various planes. The time-resolved NPLS technique was implemented to examine the time evolution characteristics of the wake flow field of roughness elements. In the following, the process of dynamic evolution of large-scale vortex structures in the wake flow field was methodically assessed. Additionally, the influences of roughness element heights on the wake vortex structure were evaluated and the obtained results were compared.

Background: The human microbiota plays several roles in health and disease but is often difficult to determine which part is in intimate relationships with the host vs. the occasional presence. During the Mars500 mission, six crewmembers lived completely isolated from the outer world for 520 days following standardized diet regimes. The mission constitutes the first spaceflight simulation to Mars and was a unique experiment to determine, in a longitudinal study design, the composition and importance of the resident vs. a more variable microbiota—the fraction of the human microbiota that changes in time and according to environmental conditions—in humans. Methods: Here, we report the characterization of the salivary microbiota from 88 samples taken during and after Mars500 mission for a total of 720 days. Amplicon sequencing of the V3–V4 regions of 16S rRNA gene was performed, and results were analyzed monitoring the diversity of the microbiota while evaluating the effect of the three main variables present in the experimental system: time, diet, and individuality of each subject. Results: Results showed statistically significant effects for either time, diet, and individuality of each subject. The main contribution came from the individuality of each subject, emphasizing salivary microbiota-personalized features, and an individual-based resilience of the microbiota. Conclusions: The uniqueness of Mars500 mission, allowed to dampen the effect of environmental variables on salivary microbiota, highlighting its pronounced personalization even after sharing the same physical space for more than a year. DRuCc4_oUAP4YMwxG5Lf3T Video abstract [ABSTRACT FROM AUTHOR]

Featured Application: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. With the promise of new, more powerful neutron sources in the future, the possibilities for time-resolved neutron scattering experiments will improve and are bound to gain in interest. While there is already a large body of work on the accurate control of temperature, pressure, and magnetic fields for static experiments, this field is less well developed for time-resolved experiments on soft condensed matter and biomaterials. We present here an overview of different sample environments and technique combinations that have been developed so far and which might inspire further developments so that one can take full advantage of both the existing facilities as well as the possibilities that future high intensity neutron sources will offer. [ABSTRACT FROM AUTHOR]

Luminescence lifetime imaging plays an important role in distinguishing the luminescence decay rates in time-resolved luminescence imaging. However, traditional imaging instruments used for detecting lifetimes within milliseconds would be time-consuming when imaging ultra-long luminescence lifetimes over subseconds. Herein, we present an accessible and simple optical system for detecting lifetimes of persistent luminescence. A smartphone integrated with a UV LED, a dichroic mirror, and a lens was used for recording the persistent luminescence. With only a few seconds of data acquisition, a luminescence lifetime image could be processed from the video by exponential fitting of the gray level of each pixel to the delay time. Since this approach only requires single excitation, no synchronous control is needed, greatly simplifying the apparatus and saving the cost. The apparatus was successfully used for ultra-long luminescence lifetime imaging of mouse tissue dyed with a persistent luminescence molecule. This miniaturized apparatus exhibits huge potentiality in time-resolved luminescence imaging for luminescence study and biological detection. [ABSTRACT FROM AUTHOR]

The objective of this paper is to reveal the attenuation characteristics of a shock wave after optical breakdown in water, with laser pulses of 12-ns duration. A high time-resolved shadowgraph method is applied to capture the temporal evolutions of the cavitation bubble wall and shock wave. The experiments are carried out on a single bubble generated far away from the free surface and the rigid walls with laser pulse energies of 22 mJ, 45 mJ, and 60 mJ. The results show that a high, time-resolved, wave front velocity of the shock wave is identified, and the maximum velocity can reach up to around 4000 m/s. An asymmetric shock wave is observed at the very start of the bubble expansion stage, and the process of the sharp attenuation of wave front velocity down to sound velocity is accomplished within 310 ns. The possible relationship of the cavitation bubble and the shock wave is discussed and a prediction model, using the maximum bubble radius and the corresponding time calculated by the Gilmore model, is proposed to calculate the location of the wave front. [ABSTRACT FROM AUTHOR]

This commentary explores the use of high-resolution data from new, miniature sensors to enrich models that predict exposures to chemical substances in the workplace. To optimally apply these sensors, one can expect an increased need for new models that will facilitate the interpretation and extrapolation of the acquired time-resolved data. We identified three key modelling approaches in the context of sensor data, namely (i) enrichment of existing time-integrated exposure models, (ii) (new) high-resolution (in time and space) empirical models, and (iii) new 'occupational dispersion' models. Each approach was evaluated in terms of their application in research, practice, and for policy purposes. It is expected that substance-specific sensor data will have the potential to transform workplace modelling by re-calibrating, refining, and validating existing (time-integrated) models. An increased shift towards 'sensor-driven' models is expected. It will allow for high-resolution modelling in time and space to identify peak exposures and will be beneficial for more individualized exposure assessment and real-time risk management. New 'occupational dispersion models' such as interpolation, computational fluid dynamic models, and assimilation techniques, together with sensor data, will be specifically useful. These techniques can be applied to develop site-specific concentration maps which calculate personal exposures and mitigate worker exposure through early warning systems, source finding and improved control design and control strategies. Critical development and investment needs for sensor data linked to (new) model development were identified such as (i) the generation of more sensor data with reliable sensor technologies (achieved by improved specificity, sensitivity, and accuracy of sensors), (ii) investing in statistical and new model developments, (iii) ensuring that we comply with privacy and security issues of concern, and (iv) acceptance by relevant target groups (such as employers and employees) and stimulation of these new technologies by policymakers and technology developers. [ABSTRACT FROM AUTHOR]