Search Results (181)

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disorder that predominantly affects synovial joints, leading to inflammation, pain, and progressive joint damage. Despite therapeutic advancements, the molecular basis of established RA remains poorly defined. Methods: In this study, we conducted an untargeted plasma proteomic analysis using two-dimensional differential gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) in samples from RA patients and healthy controls in the discovery phase. Results: Significantly (ANOVA, p ≤ 0.05, fold change > 1.5) differentially abundant proteins (DAPs) were identified. Notably, upregulated proteins included mitochondrial dicarboxylate carrier, hemopexin, and 28S ribosomal protein S18c, while CCDC124, osteocalcin, apolipoproteins A-I and A-IV, and haptoglobin were downregulated. Receiver operating characteristic (ROC) analysis identified CCDC124, osteocalcin, and metallothionein-2 with high diagnostic potential (AUC = 0.98). Proteins with the highest selected frequency were quantitatively verified by multiple reaction monitoring (MRM) analysis in the validation cohort. Bioinformatic analysis using Ingenuity Pathway Analysis (IPA) revealed the underlying molecular pathways and key interaction networks involved STAT1, TNF, and CD40. These central nodes were associated with immune regulation, cell-to-cell signaling, and hematological system development. Conclusions: Our combined proteomic and bioinformatic approaches underscore the involvement of dysregulated immune pathways in RA pathogenesis and highlight potential diagnostic biomarkers. The utility of these markers needs to be evaluated in further studies and in a larger cohort of patients. Full article

A pioneering detailed comparative study of the dynamics of plasma flows generated by high-power nanosecond and high-intensity femtosecond laser pulses with similar fluences of up to $3\times {10}^4$ J/cm² is presented. The experiments were conducted on the petawatt laser facility PEARL using two types of high-power laser radiation: femtosecond pulses with energy exceeding 10 J and a duration less than 60 fs, and nanosecond pulses with energy exceeding 10 J and a duration on the order of 1 ns. In the experiments, high-velocity (>100 km/s) flows of «femtosecond» (created by femtosecond laser pulses) and «nanosecond» plasmas propagated in a vacuum across a uniform magnetic field with a strength over 14 T. A significant difference in the dynamics of «femtosecond» and «nanosecond» plasma flows was observed: (i) The «femtosecond» plasma initially propagated in a vacuum (no B-field) as a collimated flow, while the «nanosecond» flow diverged. (ii) The «nanosecond» plasma interacting with external magnetic field formed a quasi-spherical cavity with Rayleigh–Taylor instability flutes. In the case of «femtosecond» plasma, such flutes were not observed, and the flow was immediately redirected into a narrow plasma sheet (or «tongue») propagating across the magnetic field at an approximately constant velocity. (iii) Elongated «nanosecond» and «femtosecond» plasma slabs interacting with a transverse magnetic field broke up into Rayleigh–Taylor «tongues». (iv) The ends of these «tongues» in the femtosecond case twisted into vortex structures aligned with the ion motion in the external magnetic field, whereas the «tongues» in the nanosecond case were randomly oriented. It was suggested that the twisting of femtosecond «tongues» is related to Hall effects. The experimental results are complemented by and consistent with numerical 3D magnetohydrodynamic simulations. The potential applications of these findings for astrophysical objects, such as short bursts in active galactic nuclei, are discussed. Full article

The sequencing of laser-induced plasma formation in multi-material systems is fundamentally governed by the interplay between material ionization thresholds and laser temporal characteristics. This study uncovers a counterintuitive phenomenon where silicon plasma precedes air filamentation at air–silicon interfaces under tight femtosecond laser focusing, which can be attributed to the significant difference in their ionization thresholds. Through time-resolved shadowgraphy with 550 fs resolution, we demonstrate that silicon plasma precedes air filamentation by approximately 3 ps, a temporal discrepancy that can be quantitatively attributed to the 137.5-fold lower ionization threshold of silicon compared to air. The combined influence of the laser temporal contrast and tight focusing geometry modulates this lead time from femtosecond to picosecond scales. This threshold-governed plasma chronology mechanism provides a new paradigm for controlling laser–material interactions, with direct implications for precision manufacturing of layered composites, depth-resolved optical diagnostics, phase-change material characterization, and 3D material architectures. Full article

A combination of microstructural, fluid inclusion, and in situ sulfur isotopic analyses of pyrite, along with major and trace element studies of the mineralization-hosting sandstone, reveals the complexity of its genesis from the Jurassic Toutunhe Formation in the Liuhuanggou sandstone-hosted uranium deposit, Southern Junggar Basin. Based on field geological investigations and the geochemical characteristics, it is concluded that the source of the ore-bearing sandstones originates from felsic igneous rocks in the Northern Tianshan and Central Tianshan regions. Through optical microscopy and scanning electron microscopy (SEM), three generations of pyrite were identified: framboidal pyrite, concentric overgrown pyrite, and sub-idiomorphic to idiomorphic cement pyrite. The sulfur isotopes of the pyrite were analyzed using laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). The results indicate that each type of pyrite has distinct sulfur isotope compositions (the framboidal pyrite: −16.85‰ to +2.16‰, the concentric overgrown pyrite: −7.86‰ to +10.32‰, the sub-idiomorphic to idiomorphic cement pyrite: +9.16‰ to +16.77‰). The framboidal pyrite and the sub-idiomorphic to idiomorphic cement pyrite were formed through bacterial sulfate reduction (BSR), while the concentric overgrown pyrite was formed through thermochemical sulfate reduction (TSR) triggered by the upward migration of hydrocarbons. The discovery of hydrocarbon inclusions provides evidence for the involvement of deep-seated reducing fluids in uranium mineralization. Uranium mineralization occurred in two distinct stages: (1) The early stage involved the interaction of uranium-bearing fluids with reductants in the mineralization-hosting strata under the influence of groundwater dynamics, leading to initial uranium enrichment. (2) The later stage involved the upward migration of deep-seated hydrocarbons along faults, which enhanced the reducing capacity of the sandstone and resulted in further uranium enrichment and mineralization. Full article

Laser-induced breakdown spectroscopy (LIBS) is an in situ analytical technique. Compared to traditional single-pulse LIBS (SP-LIBS), collinear double-pulse LIBS (DP-LIBS) is a promising technique due to its lower limit of detection for trace elements. In this paper, we analyze the spectral and image information obtained from the emissions emitted by single/double pulse (SP/DP) laser-induced plasmas. The types of laser-supported absorption (LSA) waves of the plasmas were determined according to the interactions among the ablation vapor, the ambient gas, and the laser. Furthermore, the influence mechanisms of plasma shielding on DP-LIBS signal intensity enhancement with different inter-pulse delay were investigated. In our experimental conditions, the propagation regime of SP plasma is a laser-supported combustion (LSC) wave. The DP plasmas with short inter-pulse delays show the characteristics of a laser-supported detonation (LSD) wave, and the enhancement mechanism is mainly reheating for pre-plasma. On the contrary, the DP plasmas with longer inter-pulse delays show the characteristics of a LSC wave, and the increase in laser ablation is a major contributing factor to the signal improvement. In addition, the spectral lines, which are difficult to excite by SP-LIBS, can be obtained by selecting an appropriate inter-pulse delay and setting a short delay, which provides a new idea for the measurement of trace elements. Full article

We present the Virtual Beamline (VBL) application, an interactive web-based platform for visualizing high-intensity laser–matter interactions using particle-in-cell (PIC) simulations, with future potential for experimental data visualization. These interactions include ion acceleration, electron acceleration, $\gamma$-flash generation, electron–positron pair production, and attosecond and spiral pulse generation. Developed at the ELI Beamlines facility, VBL integrates a custom-built WebGL engine with WebXR-based Virtual Reality (VR) support, allowing users to explore complex plasma dynamics in non-VR mode on a computer screen or in fully immersive VR mode using a head-mounted display. The application runs directly in a standard web browser, ensuring broad accessibility. VBL enhances the visualization of PIC simulations by efficiently processing and rendering four main data types: point particles, 1D lines, 2D textures, and 3D volumes. By utilizing interactive 3D visualization, it overcomes the limitations of traditional 2D representations, offering enhanced spatial understanding and real-time manipulation of visualization parameters such as time steps, data layers, and colormaps. Users can interactively explore the visualized data by moving their body or using a controller for navigation, zooming, and rotation. These interactive capabilities improve data exploration and interpretation, making VBL a valuable tool for both scientific analysis and educational outreach. The visualizations are hosted online and freely accessible on our server, providing researchers, the general public, and broader audiences with an interactive tool to explore complex plasma physics simulations. By offering an intuitive and dynamic approach to large-scale datasets, VBL enhances both scientific research and knowledge dissemination in high-intensity laser–matter physics. Full article

This review explores two main topics: the state-of-the-art and emerging capabilities of high-peak-power, ultrafast (picosecond and femtosecond) long-wave infrared (LWIR) laser technology based on CO₂ gas laser amplifiers, and the current and advanced scientific applications of this laser class. The discussion is grounded in expertise gained at the Accelerator Test Facility (ATF) of Brookhaven National Laboratory (BNL), a leading center for ultrafast, high-power CO₂ laser development and a National User Facility with a strong track record in high-intensity physics experiments. We begin by reviewing the status of 9–10 μm CO₂ laser technology and its applications, before exploring potential breakthroughs, including the realization of 100 terawatt femtosecond pulses. These advancements will drive ongoing research in electron and ion acceleration in plasma, along with applications in secondary radiation sources and atmospheric energy transport. Throughout the review, we highlight how wavelength scaling of physical effects enhances the capabilities of ultra-intense lasers in the LWIR spectrum, expanding the frontiers of both fundamental and applied science. Full article

Laser-driven ion acceleration is a new, rapidly developing field of research and one of the important applications of ultrafast high-peak-power lasers. In this acceleration method, extremely strong electric fields, induced by an ultrafast laser in the plasma generated by the laser–target interaction, enable the acceleration of ions to relativistic velocities on picosecond time scales and at sub-millimetre distances. This opens the prospect of constructing a fundamentally new type of high-energy ion accelerator—less complex, more compact, and cheaper than the ion accelerators operating today. This paper briefly discusses the basic mechanisms of heavy ion acceleration driven by an ultrafast high-peak-power laser and summarises the advances in experimental and numerical studies of laser-driven heavy ion acceleration. The main challenges facing this research and the prospects for the application of laser-accelerated heavy ion beams are outlined. Full article

Data on spectral line widths and shifts broadened by interactions with charged particles, for 44 lines in the spectrum of ionized tin, for collisions with electrons and H II and HeII ions, are presented as online available tables. We obtained them by employing the semiclassical perturbation theory for temperatures, T, within the 5000–100,000 K range, and for a grid of perturber densities from 10¹⁴ cm⁻³ to 10²⁰ cm⁻³. The presented Stark broadening data are of interest for the analysis and synthesis of ionized tin lines in the spectra of hot and dense stars, such as, for example, for white dwarfs and hot subwarfs, and for the modelling of their atmospheres. They are also useful for the diagnostics of laser-induced plasmas for high-order harmonics generation in ablated materials. Full article

Recently, it has been experimentally shown that the sheath acceleration of protons from ultra-thin metal targets irradiated by sub-picosecond laser pulses of intensities above ${10}^{21}$ W/cm² is suppressed compared to well-established models. This detrimental effect has been attributed to a self-generation of gigagauss-level quasi-static magnetic fields in expanded plasmas on the rear side of a target. Here we present a set of numerical simulations which support this statement. Based on 2D full-scale PIC simulations, it is shown that the scaling of a cutoff energy of the accelerated protons with intensity deviates from a well-established Mora model for laser pulses with a duration exceeding 500 fs. This deviation is showed to be connected to effective magnetization of the hottest electrons producing at the maximum of the laser pulse intensity. We propose a modification of the Mora model which incorporates the effect of the possible electron magnetization. Comparing it to the simulation results shows that by appropriately choosing a single fitting parameter, the model produces results that quantitatively coincide with simulations. Full article

This work studied the pre-plasma that builds up in interactions of focused high-power PW-class lasers with solid targets at the target surface facing the laser beam, and its impact on the global laser absorption efficiency as well as on the spectral cut-off energy of laser-generated proton beams. Our practical heuristic estimates were derived from the example of the VEGA-3 laser at CLPU. Our modeling results for the pre-plasma expansion due to the laser pedestal of VEGA-3 were benchmarked by hydrodynamic simulations, revealing good agreement for the evolution before the arrival of the main Gaussian laser intensity peak. Our detailed numerical two-dimensional Particle-in-Cell simulations showed the impact of different pre-plasma scale lengths on the absorption efficiency of laser energy into electrons, relevant for the seeding of other types of radiation. It was shown that the absorption can increase manyfold when increasing the pre-plasma scale length. This effect can be beneficial for the spectral cut-off energy of accelerated protons, where a trade-off between absorption and electron dynamics yields an optimum pre-plasma scale length. The findings can be applied to other PW-class laser facilities. Full article

The role of pre-plasma in the efficient generation of protons by intense laser-matter interaction from structured targets is investigated. Optimal energy coupling between laser and plasma is found by varying the fluence and arrival time of an independently controllable ultrashort pre-pulse with respect to the main interaction pulse. The coupling is evaluated based on the energy of the accelerated protons. The accelerated proton energy is maximized at optimal pre-pulse delay and fluence conditions. Plasma emission spectrum and Particle-in-Cell simulations provide a possible explanation of the obtained experiment results. Full article

The interaction of pulsed lasers with matter involving nanomaterials as a pure target or thin layer deposited on a target initiates transient plasma, which shows strong enhancement in a spectral line emission. This domain of research has been explored via two well-established techniques dubbed NELIBS and NELIPS. These Nano-Enhanced Laser-Induced Breakdown or Plasma Spectroscopy techniques entail similarities as well as differences. The newly defined concept of Nano-Enhanced Laser-Induced Plasma Spectroscopy NELIPS is introduced. Thereupon, certain confusion has arisen from various aspects of the similarities as well as differences between the two techniques. In this article, we will investigate the application of either technique to retrieve relevant data about the enhanced spectral line plasma emission phenomenon. To discriminate between these two techniques, a survey on the nature of the target, the origin of enhancement and prevalent theoretical approaches is presented. In this context, the potential achievements, challenges and expected prospects are comparatively highlighted. This review emphasizes the unique contributions of NELIPS, particularly the advanced approach in nanoscale thermal modeling and spectroscopic applications. Full article

(1) Background: Ultrashort high-energy laser pulses may cause interaction mechanisms, including photodisruption and plasma-induced ablation in the medium. It is not always easy to distinguish between these two processes, as both interaction mechanisms rely on plasma generation and overlap. The purpose of this paper is to discuss prominent cavitation bubble models describing photodisruption and plasma-induced ablation and to explore their nature for different threshold energies. This exploration will help to better distinguish the two interaction mechanisms. As a second aim, we present an alternative model for the low-energy regime close to the laser-induced optical breakdown (LIOB) threshold, representing the phenomenological effect of the plasma-induced ablation regime. (2) Methods: The cavitation bubble models for photodisruption and plasma-induced ablation were used to calculate the bubble radius for a series of threshold energies (E_Th = 30, 50, 70, and 300 nJ) that loosely represent commercial systems currently used in ultrashort-pulse tissue ablation. Taking a photodisruption model coefficient commonly used in the literature, the root mean square error between the two interaction models was minimized using the generalized reduced gradient fitting method to calculate the optimum scaling factors for the plasma model. The refined models with optimized coefficients were compared for a range of pulse and threshold energies. (3) Results: For low E_Th (30, 50, and 70 nJ), the plasma-induced ablation model dominates for low energies that are close to the threshold energy. The photodisruption model dominates for high energies that are well above the threshold energy. At very high pulse energies, for all the simulated cases, the photodisruption model transitions and crosses over to the plasma-induced ablation model. The cross-over points from which the photodisruption model dominates tend to be reduced for larger E_Th. A new universally applicable model for plasma-induced ablation has been hypothesized that considers the cavitation bubble volume and potentially better explains the bubble dynamics during intrastromal processes. (4) Conclusions: This theoretical exploration and the comparison of the outcomes to empirical data substantiate that inadvertently using the photodisruption model to explain the cavitation bubble dynamics for the entire spectrum of pulse energies and laser systems might provide erroneous estimates of cavitation bubble sizes. A reliable estimate of the true size (the maximum radius) of the cavitation bubble can be reasonably retrieved as the maximum predicted size from the fit of the photodisruption model and the newly proposed plasma-induced ablation model at any given pulse energy. Full article

An overview of the 200 TW Frascati Laser for Acceleration and Multidisciplinary Experiments (FLAME) at the SPARC_LAB Test Facility at the National Laboratories of Frascati (LNF-INFN) is presented. The FLAME laser is employed to investigate different laser–matter interaction schemes, i.e., electron acceleration and secondary radiation sources through Laser Wakefield Acceleration (LWFA) or ion and proton generation through Target Normal Sheath Acceleration (TNSA), for a wide range of scientific areas including the biomedical applications. Finally, recently performed experimental campaigns within the EuAPS and EuPRAXIA frameworks are reported. Full article