Search Results (148)

This study examines the applicability of Plasma Transferred Arc (PTA) surface treatment as an advanced technique for the refurbishment of railway wheel treads. Conventional wheel reprofiling, typically performed on semi-automatic lathes, requires the removal of a minimum of 6 mm of material from the running surface, which accelerates rim thinning and ultimately necessitates wheel replacement. Moreover, the reprofiled surfaces are not subjected to any subsequent treatment aimed at enhancing their durability. To overcome these limitations, PTA cladding was selected due to its ability to generate surface layers with superior mechanical and tribological properties. In contrast to widely used diode laser technologies, PTA enables the deposition of alloying materials in powder form, ensuring a stable, controllable, and efficient cladding process. The resulting microstructure consists of a heat-affected zone, a transition zone, and a re-melted zone, each exhibiting significantly increased hardness relative to the untreated base material. The process facilitates the incorporation of metallic particles into the surface layer, promoting the formation of a dense, wear-resistant coating. These materials possess huge potential utility regarding the wear resistance reaching even ca 10% of the base material wear in the case of 505 PTA and over 20% in the case of the 15 E material. The findings indicate that PTA surface treatment has substantial potential to extend the operational lifespan of railway wheels by providing a highly durable and mechanically robust surface, thereby reducing maintenance frequency and the associated costs. Full article

Additive manufacturing (AM) has emerged as a transformative manufacturing technology for producing complex components with unprecedented design flexibility. However, the widespread application of AM parts in tribological environments is often limited by inherent defects such as high surface roughness, porosity, residual stresses, anisotropy, and weak interlayer bonding, which adversely affect friction, wear resistance, and tribocorrosion performance. This review critically examines the tribological behavior of AM materials and components, emphasizing the influence of processing routes, material selection, secondary reinforcing phases, and microstructural evolution on tribological performance. Particular attention is given to surface engineering strategies, including thermal spray coatings, laser surface treatments, plasma electrolytic oxidation, vapor deposition technologies, and mechanical surface modification techniques for mitigating AM-induced defects and improving surface durability. Recent advances in machine learning (ML) and artificial intelligence (AI) for wear prediction, process optimization, and intelligent tribological monitoring are also discussed. The review highlights the relationships among manufacturing parameters, surface integrity, and wear mechanisms, while identifying key challenges associated with process variability, long-term reliability, and industrial implementation. Future research should focus on multifunctional surface systems, smart coatings, real-time condition monitoring, and data-driven design approaches to accelerate the deployment of tribologically optimized AM components in aerospace, biomedical, automotive, and energy applications. Full article

One of the main technological challenges in plasma wakefield acceleration (PWFA) research and development is achieving stable and reproducible acceleration. In particular, for PWFA schemes based on particle-driven plasma wave excitation, beam stability and timing jitter are increasingly critical. In these configurations, magnetic or radio-frequency (RF) compression schemes are often used, and the beam time-of-arrival jitter at the end of the linear accelerator can be strongly correlated with the phase noise of RF accelerating structures operated off-crest. For this reason, since 2008, an RF phase fast-feedback system acting within each RF pulse has been successfully implemented at Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare (LNF-INFN) at the Sources for Plasma Accelerators and Radiation Compton with Laser And Beam (SPARC_LAB) facility, operating on both S-band ($2.856$ GHz) and C-band ($5.712$ GHz) klystrons. This paper presents the upgrade and optimization of the fast-feedback system for an S-band klystron powered by a pulse-forming network modulator. This technology introduces significantly higher intrinsic phase noise than, for instance, solid state-based modulators. It is therefore essential to minimize such phase fluctuations to keep the machine stability under control. Both the feedback hardware (electronic boards and RF circuitry) and the software (controller and user interface) have been upgraded. Tests performed at SPARC_LAB achieved a reduction in klystron-induced jitter of a factor of 30, reaching values below 15 fs rms on both power plants. Moreover, adding a remote control of the feedback loop enabled a straightforward optimization of the operating point, allowing the phase stability performance to be pushed close to its practical limits. A detailed analysis of RF phase noise measurements with the fast-feedback loop in operation is also presented. Full article

Nowadays, there is a deep interest in developing more compact user facilities, and plasma technology is one of the most promising techniques, not only for acceleration modules, but also for what is ancillary to the delivery of radiation to users, such as free electron lasers. In this regard, significant efforts have been made to miniaturize diagnostic stations, detection devices, and transfer lines, e.g., based on active plasma lenses. However, conventional undulators are still too cumbersome and expensive to meet the requirements of compactness and sustainability. For the aforementioned reasons, advanced undulator concepts have aroused great interest in pushing the frontier beyond conventional, magnet-based undulators. In this regard, a promising, very compact alternative is the use of the betatron motion of electrons in an ion channel to emulate an undulator device. This paper reports a feasibility study aiming to develop plasma-based undulator devices at SPARC_LAB as the test facility of the EuPRAXIA@SPARC_LAB project. In particular, this work provides a systematic assessment of free-electron-laser amplification in a plasma ion-channel undulator under experimentally realistic beam parameters, delivering quantitative predictions for gain and radiation performance in this configuration. Full article

Polydeoxyribonucleotide (PDRN) activates the adenosine A2A receptor (A2AR), triggering anti-inflammatory signaling and providing essential nucleotides for the salvage pathway, thereby helping bypass metabolic bottlenecks and promoting tissue repair. Combining PDRN with biochemical agents and physical stimuli represents a significant shift in medical treatment, moving from monotherapy to an integrated, multi-target regenerative approach. These combinatorial strategies effectively address the limitations of PDRN, such as its rapid degradation and diffusion, by simultaneously meeting the structural, metabolic, and signaling needs of injured tissues. The mechanism of action for PDRN involves a synergistic effect with hyaluronic acid, amplification of growth factors (e.g., Platelet-Rich Plasma (PRP), Epidermal Growth Factor (EGF), Platelet-Derived Growth Factor (PDGF)), and enhancements from extracorporeal shockwave therapy (ESWT) and lasers. This results in a notable acceleration of the repair process for chronic wounds, musculoskeletal disorders, and neurological injuries. As intelligent delivery systems like responsive hydrogels and sustainable L-PDRN production continue to advance, these synergistic protocols are poised to redefine global standards of care in regenerative medicine and esthetic dermatology. Future clinical success will hinge on the standardization of sequence-specific protocols and large-scale validation to ensure long-term safety and efficacy. Full article

We investigate laser wakefield electron acceleration in a periodic plasma density profile using 2D PIC simulations with the EPOCH code. The profile of the electron density has the form $n\left(x\right)=n_0\left(1+\delta sin2\pi x/x_0\right)$, where $n_0$ is the steady electron density, $x_0=100\mathrm{m}$ is the spatial periodicity in the laser propagation direction and $\delta$, taking the values 0, $0.1$, $0.3$, $0.5$ and $0.7$, is the modulation parameter. The bubble size varies with the modulated plasma density, thereby influencing the electron acceleration, which occurs within a continuously changing bubble structure. We propose an analytical model to estimate the energies of the accelerated electrons, and evaluate the maximum electron energies at $500 \mathrm{f}\mathrm{s}$ intervals for the five modulated density profiles. We then calculate the dephasing and depletion lengths for these modulated plasma profiles and examine their dependence on $\delta$. The results show a growth in both lengths with $\delta$, with depletion being the main limitation in these cases. Additionally, we compute and compare the transverse emittance of the self-injected electron bunches corresponding to the various density profiles at the same simulation time, and other characteristics, like the center energy and energy spread. Emittance is observed to experience a decrease with the increase in the modulation parameter. Full article

Diabetes mellitus affects an estimated 589 million adults globally, and cutaneous manifestations occur in up to 70% of affected individuals during the course of the disease. The objective of this narrative review is to examine the intersection of diabetes mellitus, skin aging, cosmetic dermatologic procedures, and regenerative therapies, with an emphasis on evidence-based best practices and clinical considerations. While the impaired wound healing associated with diabetes has been extensively studied, the aesthetic implications of diabetic skin disease remain comparatively underexplored. Individuals with diabetes frequently exhibit features of accelerated cutaneous aging, including premature wrinkling, dyschromia, xerosis, alopecia, and other cosmetically significant dermatoses that may negatively impact quality of life. In parallel, the demand for aesthetic dermatologic procedures among patients with diabetes has increased substantially; however, evidence-based recommendations guiding the safe and effective use of cosmetic interventions in this population remain limited. Diabetic skin demonstrates accelerated biological aging driven by complex pathophysiological mechanisms, including the accumulation of advanced glycation end products, chronic low-grade inflammation, oxidative stress, microvascular dysfunction, and neuropathy. These processes partially overlap with chronological aging and photoaging but are mechanistically distinct and may influence tissue repair, inflammatory responses, and the safety profile of commonly performed aesthetic procedures such as chemical peels, laser resurfacing, dermal fillers, neuromodulators, and microneedling. Emerging regenerative approaches, including platelet-rich plasma, platelet lysate, and mesenchymal stromal cell-derived products such as exosomes and secretomes, have attracted increasing attention as biologically targeted strategies for cutaneous rejuvenation. Nevertheless, clinical evidence specifically addressing aesthetic interventions in diabetic populations remains limited. A diabetes-informed approach to aesthetic dermatology that considers metabolic status, procedure selection, and post-procedural monitoring is therefore essential to optimize safety and therapeutic outcomes. Full article

Dental implants have become common for restoring function and aesthetics after edentulism, with titanium (Ti) remaining the most widely used material due to its excellent mechanical properties and biocompatibility. Despite their clinical success, long-term performance is strongly influenced by surface characteristics, which regulate osseointegration and susceptibility to bacterial colonisation. Consequently, surface modification approaches have become critical strategies to enhance implant stability, bioactivity and longevity. This review critically evaluates conventional, advanced, and hybrid surface modification strategies. Subtractive methods, such as sandblasting and acid etching, increase microroughness (Ra 1.5–3 μm), enhancing osteoblast attachment and differentiation, but may promote bacterial adhesion and surface contamination. Combined treatments like SLA and SLActive generate hierarchical micro–nano topographies, improving protein adsorption, early-stage osteoblast proliferation (up to 2-fold), and clinical stability. Laser ablation and photofunctionalisation further modulate surface chemistry and wettability, accelerating osseointegration and epithelial cell adhesion. Coating approaches, including layer-by-layer self-assembly, nanospray drying, plasma spraying, and piezoelectric nanocomposites, introduce antimicrobial activity (>95% reduction in Escherichia coli or Staphylococcus aureus) and enhanced osteogenic differentiation with mechanical stability, with adhesion values reaching 49 MPa. Hybrid techniques such as sol–gel, hydrothermal, and anodisation provide controlled topography, chemical composition, and bioactivity, promoting early bone-to-implant contact (BIC increase of 10%–25%) in preclinical models. Notwithstanding promising in vitro and in vivo outcomes, variability in processing parameters and limited standardisation restrict large-scale clinical translation. Overall, contemporary Ti surface engineering emphasises a synergistic balance of topography, chemistry, wettability, and hierarchical structuring to optimise biological performance for dental implant applications. Full article

This study employs a comprehensive bibliometric analysis to map the global scientific landscape of laser wakefield acceleration (LWFA) from 1990 to 2025. Using data extracted from the Web of Science (WoS) and analyzed with Bibliometrix, VOSviewer, and CiteSpace, the study identifies key publication trends, influential authors, leading countries, prominent journals, and thematic evolution within the field. The findings reveal exponential growth in LWFA-related research, driven by advances in high-power laser technology and controlled injection techniques. Network analyses demonstrate extensive international collaboration and a strong interdisciplinary structure linking plasma physics, optics, and accelerator science. Keyword co-occurrence and burst analyses highlight emerging topics such as ionization injection, dual-stage acceleration, betatron radiation, and machine learning-assisted optimization. These insights delineate both the historical progression and the dynamic frontiers of LWFA, providing a systematic understanding of its development and guiding future research toward the realization of compact, high-quality electron sources and next-generation plasma-based accelerators. Full article

The present article reports on the generation of stable 50 pC low-divergence electron beams above 150 MeV from laser-driven wakefield acceleration using a continuous-flow gas target prototype tested at the 60 TW Salle Jaune facility at LOA. The gas target design is meant to be easily transported and integrated as an element of the beamline with a differential pumping system offering some 10⁻⁴ mbar pressure in the rest of the line. A dedicated gas injection system allows for the control of the gas mixture concentration and gas pressure in two different regions of the target within the frame of controlled ionisation injection schemes. The measured electron beam parameters show the importance of gas density profiles and longitudinal gas mixture confinement. Full article

Background and Objectives: Soft tissue regeneration in oral surgery has undergone remarkable progress in the last decade, supported by the development of innovative laser technologies, advanced biomaterials, platelet-rich plasma (PRP), mesenchymal stem cells (MSCs), and three-dimensional (3D) printing. Lasers are increasingly used not only for incision and coagulation but also for photobiomodulation, promoting cellular proliferation, angiogenesis, and tissue healing. The purpose of this review is to analyze the current advances in soft tissue regeneration, with a particular focus on the clinical use of lasers and their integration with other regenerative strategies. In parallel, hard tissue regeneration has evolved through the synergistic use of bioactive scaffolds, recombinant human growth factors (rhBMP-2, rhPDGF-BB), MSCs, and 3D-printed constructs. These innovations have enhanced alveolar bone regeneration, implant osseointegration, and periodontal tissue repair, offering predictable clinical outcomes. Materials and Methods: A review of the literature published between 2015 and 2025 was conducted through PubMed, Scopus, Web of Science, Embase, and Google Scholar. Clinical and preclinical studies on the use of CO₂, Nd:YAG, Er:YAG, diode, and 445 nm lasers, biomaterials, PRP, MSCs, growth factors, and 3D-printed scaffolds were included. Results: Laser applications demonstrated significant benefits in epithelialization, biostimulation, and reduction in postoperative discomfort in soft tissues. For hard tissues, the combined use of MSCs, bioactive scaffolds, and growth factors promoted osteogenic differentiation, bone volume preservation, and improved mechanical stability. Photobiomodulation enhanced osteoblastic activity and accelerated bone remodeling, while 3D-printed scaffolds provided personalized architecture for optimal integration. Conclusions: Regenerative approaches integrating lasers, biomaterials, PRP, MSCs, growth factors, and 3D printing represent safe, minimally invasive, and effective strategies for the regeneration of both soft and hard oral tissues. These multidisciplinary techniques improve healing quality, functional recovery, and esthetic outcomes, reflecting the growing trend toward precision and technology-driven regenerative oral surgery. Full article

We present a systematic study on the optical response of plasma mirrors generated in polymer foils under ultrashort laser pulse irradiation within the non-relativistic intensity regime, reaching up to $2\times {10}^{17}$ W/cm². Using a Ti:sapphire system that delivers 50 fs pulses, we simultaneously measured reflection, transmission, and diffuse scattering with three energy meters for single-shot laser energies of 5, 10, 15, and 20 mJ as a function of the laser spot size on the target. The results reveal intensity-dependent variations in reflectivity, accompanied by simultaneous changes in transmission and scattering, allowing to estimate laser energy absorption by the polymer. Morphological analysis of the plasma surface suggests a significant role in modifying energy absorption, with implications for the efficiency of processes such as laser particle acceleration, nuclear fusion, and attosecond pulse generation. These findings provide critical insights into plasma mirror formation, absorption dynamics in polymers, and the potential of nanostructured polymer targets in high-intensity laser–matter interaction applications. Full article

Background/Objectives: Recurrent oral ulcers (ROUs) are a common condition that significantly impacts patients’ quality of life. This pilot study was conducted to evaluate the feasibility and preliminary results of using non-thermal plasma (NTP) compared to low-level laser therapy (LLLT) and placebo to treat these ulcers. Methods: A prospective, controlled, randomised, parallel-group pilot study was conducted using a convenience sample of 50 patients with ROUs. Patients were randomly assigned (2:2:1) to one of three groups: NTP (n = 20), LLLT (n = 20), and placebo (n = 10). Feasibility and preliminary data acquisition were the primary goals. Exploratory outcomes included ulcer size reduction and safety profile. This was a single-blinded trial, where participants and outcome assessors were masked to group assignment. Ulcer size, pain perception, and time to complete healing were measured. For statistical analysis, ANOVA was used, with a p-value ≤ 0.05. Results: The groups were comparable at baseline. Exploratory results suggest that NTP demonstrated a promising trend in accelerating healing, with a mean healing time difference of 5.5 days compared to LLLT (2.5 ± 1.9 days vs. 8.0 ± 4.3 days) and 7.1 days compared to placebo (2.5 ± 1.9 days vs. 9.6 ± 5.3 days) (p < 0.001). Regarding pain, NTP provided significant and sustained relief. Patients in the NTP group were asymptomatic on day 2, unlike the LLLT and placebo groups, where pain persisted significantly (NTP VAS score at 1 h: 1.1 ± 2.1 vs. LLLT/Placebo VAS score at 1 h: 3.4 ± 2.4 and 7.3 ± 1.9, respectively) (p < 0.001). NTP was well tolerated, and no adverse events were reported. Conclusions: This pilot study suggests that NTP is a potentially safe and effective therapy for recurrent oral ulcers. Preliminary results indicate that it may accelerate healing and offer superior pain relief, warranting a large-scale clinical trial to confirm these findings. Full article

Laser-driven ion acceleration is a rapidly developing branch of plasma physics and laser science whose primary practical goal is to provide a physical and technological basis for the construction and development of new types of ion accelerators. Laser-driven accelerators can be less complex and more compact than currently used RF-driven accelerators, while the intensities, fluences, and powers of laser-accelerated ion beams can potentially exceed those achieved in RF accelerators. This paper focuses on the generation of very intense ion beams driven by a multi-PW femtosecond laser. The acceleration mechanisms enabling the generation of such beams are characterized, and the properties of multi-PW laser-driven uranium ion beams are discussed in detail based on the results of advanced particle-in-cell numerical simulations. The feasibility of generating sub-picosecond, multi-GeV, mono-charge uranium beams with extreme intensities (~>10²⁰ W/cm²) and fluences (~>GJ/cm²) is demonstrated, and methods for controlling the beam parameters are identified. It is shown that using such beams, extreme states of matter with parameters unattainable with ion beams from conventional accelerators can be created. The prospects for applications of ultra-intense laser-driven ion beams in high-energy density physics, inertial confinement nuclear fusion, and in certain areas of nuclear physics are outlined. Full article

EuPRAXIA@SPARC_LAB is an FEL (Free-Electron Laser) user facility currently under construction at INFN-LNF in the framework of the EuPRAXIA collaboration. The electron beam will be accelerated to 1 GeV by an X-band RF linac followed by a plasma wakefield acceleration stage. This high-brightness linac requires diagnostic devices able to measure the beam parameters with high accuracy and resolution. To monitor the beam energy and its spread, magnetic dipoles and quadrupoles will be installed along the linac, in combination with viewing screens and CMOS cameras. Macroparticle beam dynamics simulations have been performed to determine the optimal energy measurement setup in terms of accuracy and resolution. Similar diagnostics evaluations have been carried out for the spectrometer installed at the 100 MeV RF linac of the radioactive beam facility SSRIP (IFIN-HH, Romania), whose commissioning, foreseen for 2026, will be performed by INFN-LNF in collaboration with IFIN-HH. Optics measurements have been performed to characterize the resolution and magnification of the optical system that will be used at SSRIP, and probably also at EuPRAXIA@SPARC_LAB, for beam energy monitoring. Full article