Search Results (294)

Helium (He) accumulation in tungsten—widely used as a plasma-facing material in fusion reactors—can lead to clustering, trap mutation, and eventual formation of helium bubbles, critically impacting material performance. To clarify the atomic-scale mechanisms governing this process, we conducted systematic molecular statics and molecular dynamics simulations across a wide range of vacancy cluster sizes (n = 1–27) and temperatures (500–2000 K). We identified the onset of trap mutation through abrupt increases in tungsten atomic displacement. At 0 K, the critical helium-to-vacancy (He/V) ratio required to trigger mutation was found to scale inversely with cluster size, converging to ~5.6 for large clusters. At elevated temperatures, thermal activation lowered the mutation threshold and introduced a distinct He/V stability window. Below this window, clusters tend to dissociate; above it, trap mutation occurs with near certainty. This critical He/V ratio exhibits a linear dependence on temperature and can be described by a size- and temperature-dependent empirical relation. Our results provide a quantitative framework for predicting trap mutation behavior in tungsten, offering key input for multiscale models and informing the design of radiation-resistant materials for fusion applications. Full article

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease predominantly of the small airways and parenchyma. COPD lungs exhibit an influx of circulating innate immune cells, which, when isolated, display impaired functions, including imbalanced protease secretion. In addition to immune cells, the extracellular matrix (ECM) plays a crucial role in COPD pathology. Remodeling of the ECM can generate ECM fragments, which can be released into circulation and subsequently induce pro-inflammatory responses. COPD is a heterogeneous disease, and serological biomarkers can be used to sub-categorize COPD patients for targeted treatments and optimal recruitment in clinical trials. This study evaluated fragments of calprotectin, collagen type VI, and versican, generated by neutrophil elastase and matrix metalloproteinases (MMP-) 2 and 12, respectively, as potential biomarkers of COPD disease, severity, and endotypes. Lower plasma levels of a neoepitope marker of calprotectin, indicative of activated neutrophils (nordicCPa9-HNETM), were detected in COPD donors compared to controls. CPa9-HNE was associated with milder disease, higher degree of air-trapping, and higher serum levels of MMP-2. Deposition of CPa9-HNE levels in lung tissue revealed no differences between groups. Taken together, CPa9-HNE was found to be a potential marker of mild COPD, but further studies are warranted to validate our findings. Full article

We investigate how collisional interactions between the condensate and the thermal cloud influence the distinct dynamical regimes (Josephson plasma, phase-slip-induced dissipative regime, and macroscopic quantum self-trapping) emerging in ultracold atomic Josephson junctions at non-zero subcritical temperatures. Specifically, we discuss how the self-consistent dynamical inclusion of collisional processes facilitating the exchange of particles between the condensate and the thermal cloud impacts both the condensate and the thermal currents, demonstrating that their relative importance depends on the system’s dynamical regime. Our study is performed within the full context of the Zaremba–Nikuni–Griffin (ZNG) formalism, which couples a dissipative Gross–Pitaevskii equation for the condensate dynamics to a quantum Boltzmann equation with collisional terms for the thermal cloud. In the Josephson plasma oscillation and vortex-induced dissipative regimes, collisions markedly alter dynamics at intermediate-to-high temperatures, amplifying damping in the condensate imbalance mode and inducing measurable frequency shifts. In the self-trapping regime, collisions destabilize the system even at low temperatures, prompting a transition to Josephson-like dynamics on a temperature-dependent timescale. Our results show the interplay between coherence, dissipation, and thermal effects in a Bose–Einstein condensate at a finite temperature, providing a framework for tailoring Josephson junction dynamics in experimentally accessible regimes. Full article

This study systematically investigates the effects of trap concentration on self-heating and terahertz (THz) responses in GaN HEMTs using Sentaurus TCAD. Traps, inherently unavoidable in semiconductors, can be strategically introduced to engineer specific energy levels that establish competitive dynamics between the electron momentum relaxation time and the carrier lifetime. A simulation-based exploration of this mechanism provides significant scientific value for enhancing device performance through self-heating mitigation and THz response optimization. An AlGaN/GaN heterojunction HEMT model was established, with trap concentrations ranging from 0 to $5\times {10}^{17} {\mathrm{c}\mathrm{m}}^{-3}$. The analysis reveals that traps significantly enhance channel current (achieving 3× gain at $1\times 10^{17} {\mathrm{c}\mathrm{m}}^{-3}$) via new energy levels that prolong carrier lifetime. However, elevated trap concentrations (>$1\times {10}^{16} {\mathrm{c}\mathrm{m}}^{-3}$) exacerbate self-heating-induced current collapse, reducing the min-to-max current ratio to 0.9158. In THz response characterization, devices exhibit a distinct DC component (${\mathrm{U}}_{\mathrm{d}\mathrm{c}}$) under non-resonant detection ($\mathsf{\omega }\mathsf{\tau }\ll 1$). At a trap concentration of $1\times {10}^{15} {\mathrm{c}\mathrm{m}}^{-3}$, ${\mathrm{U}}_{\mathrm{d}\mathrm{c}}$ peaks at $0.12 \mathrm{V}$ when ${\mathrm{V}}_{\mathrm{g}}\mathrm{D}\mathrm{C}=-7.8 \mathrm{V}$. Compared to trap-free devices, a maximum response attenuation of 64.89% occurs at ${\mathrm{V}}_{\mathrm{g}}\mathrm{D}\mathrm{C}=-4.9 \mathrm{V}$. Furthermore, ${\mathrm{U}}_{\mathrm{d}\mathrm{c}}$ demonstrates non-monotonic behavior with concentration, showing local maxima at $4\times {10}^{15} {\mathrm{c}\mathrm{m}}^{-3}$ and $7\times {10}^{15} {\mathrm{c}\mathrm{m}}^{-3}$, attributed to plasma wave damping and temperature-gradient-induced electric field variations. This research establishes trap engineering guidelines for GaN HEMTs: a concentration of $4\times {10}^{15} {\mathrm{c}\mathrm{m}}^{-3}$ optimally enhances conductivity while minimizing adverse impacts on both self-heating and the THz response, making it particularly suitable for high-sensitivity terahertz detectors. Full article

The GaN-based green miniaturized light-emitting diode (mini-LED) is a key component for the realization of full-color display. Optimized passivation layers can alleviate the trapping of carriers by sidewall defects and are regarded as an effective way to improve the external quantum efficiency (EQE) efficiency of mini-LEDs. Since AlN has a closer lattice match to GaN compared to other heterogeneous passivation materials, we boosted the EQE of GaN-based green flip-chip mini-LEDs through the deposition of a lattice-compatible AlN passivation layer through atomic layer deposition (ALD) and a SiO₂ passivation layer through plasma-enhanced chemical vapor deposition (PECVD). Benefiting from reduced sidewall nonradiative recombination, the EQE of the green flip-chip mini-LED with a composite ALD-AlN/PECVD-SiO₂ passivation layer reached 34.14% at 5 mA, which is 34.6% higher than that of the green flip-chip mini-LED with a single PECVD-SiO₂ passivation layer. The results provide guidance for the realization of high-performance mini-LEDs by selecting lattice-compatible passivation layers. Full article

High-Bandwidth Memory (HBM) enables the bandwidth required by modern AI and high-performance computing, yet its three dimensional stack traps heat and amplifies thermo mechanical stress. We first review how conventional solutions such as heat spreaders, microchannels, high density Through-Silicon Vias (TSVs), and Mass Reflow Molded Underfill (MR MUF) underfills lower but do not eliminate the internal thermal resistance that rises sharply beyond 12layer stacks. We then synthesize recent hybrid bonding studies, showing that an optimized Cu pad density, interface characteristic, and mechanical treatments can cut junction-to-junction thermal resistance by between 22.8% and 47%, raise vertical thermal conductivity by up to three times, and shrink the stack height by more than 15%. A meta-analysis identifies design thresholds such as at least 20% Cu coverage that balances heat flow, interfacial stress, and reliability. The review next traces the chain from Coefficient of Thermal Expansion (CTE) mismatch to Cu protrusion, delamination, and warpage and classifies mitigation strategies into (i) material selection including SiCN dielectrics, nano twinned Cu, and polymer composites, (ii) process technologies such as sub-200 °C plasma-activated bonding and Chemical Mechanical Polishing (CMP) anneal co-optimization, and (iii) the structural design, including staggered stack and filleted corners. Integrating these levers suppresses stress hotspots and extends fatigue life in more than 16layer stacks. Finally, we outline a research roadmap combining a multiscale simulation with high layer prototyping to co-optimize thermal, mechanical, and electrical metrics for next-generation 20-layer HBM. Full article

In this study, particle-in-cell (PIC) simulation was used to validate a conceptual design for a quasi-spherical, net power, hydrogen-plus-boron-11-fueled fusion reactor incorporating high-temperature superconducting (HTS) magnets. By burning a fully thermalized plasma, our proposed MET6 reactor uses the principles of the 1980 magneto-electrostatic trap design of Yushmanov to improve the classic Polywell design. Because the input power consumed by the reactor will barely balance the waste bremsstrahlung radiation, future research must focus on reducing the bremsstrahlung losses to reach practical net power levels. The first step to reducing bremsstrahlung, explored in this paper, is to tune the reactor parameters to reduce the energies of trapped electrons. We assume the quality factor Q can be approximated as the ratio of fusion power output divided by bremsstrahlung power loss. Thus, assuming the particles’ power loss is negligible compared to bremsstrahlung power loss, the resulting quality factor is estimated to be Q ≈ 1.3. Full article

In swine reproduction, immune-mediated mechanisms such as neutrophil extracellular trap (NET) formation can affect sperm function and reduce fertility outcomes. This study evaluated the capacity of antioxidant and reproductive compounds—butylated hydroxytoluene (BHT), prostaglandin E₂ (PGE₂), bovine serum albumin (BSA), and seminal plasma (SP)—to modulate NETosis in co-cultures of swine neutrophils and cryopreserved spermatozoa. NET formation was quantified by nuclear area expansion and validated by digital cytometry and immunofluorescence. BHT (0.5 mM) and PGE₂ (10 µM) produced the most significant inhibitory effects, reducing NETotic cell percentages from 34.5 ± 2.7% (sperm-exposed controls) to 12.2 ± 1.3% and 14.5 ± 2.1%, respectively (p < 0.01). SP at 20% decreased NETosis to 16.8 ± 1.8%, while BSA (0.5%) achieved a moderate reduction to 21.3 ± 2.5%. Flow cytometry revealed reduced peroxynitrite levels in sperm treated with SP and BSA. Two NET phenotypes (aggNETs and sprNETs) were identified. BTS medium enhanced NET formation, whereas DNase I degraded NETs effectively. These findings identify porcine NETosis as a redox-sensitive pathway modulated in vitro, suggesting an immunological role in enhancing sperm preservation for swine artificial insemination. Full article

Laboratory magnetoplasmas can become an intriguing experimental environment for fundamental studies relevant to nuclear astrophysics processes. Theoretical predictions indicate that the ionization state of isotopes within the plasma can significantly alter their lifetimes, potentially due to nuclear and atomic mechanisms such as bound-state β-decay. However, only limited experimental evidence on this phenomenon has been collected. PANDORA (Plasmas for Astrophysics, Nuclear Decay Observations, and Radiation for Archaeometry) is a novel facility which proposes to investigate nuclear decays in high-energy-density plasmas mimicking some properties of stellar nucleosynthesis sites (Big Bang Nucleosynthesis, s-process nucleosynthesis, role of CosmoChronometers, etc.). This paper focuses on the case of ⁷Be electron capture (EC) decay into ⁷Li, since its in-plasma decay rate has garnered considerable attention, particularly concerning the unresolved Cosmological Lithium Problem and solar neutrino physics. Numerical simulations were conducted to assess the feasibility of this possible lifetime measurement in the plasma of PANDORA. Both the ionization and atomic excitation of the ⁷Be isotopes in a He buffer Electron Cyclotron Resonance (ECR) plasma within PANDORA were explored via numerical modelling in a kind of “virtual experiment” providing the expected in-plasma EC decay rate. Since the decay of ⁷Be provides γ-rays at 477.6 keV from the ⁷Li excited state, Monte-Carlo GEANT4 simulations were performed to determine the γ-detection efficiency by the HPGe detectors array of the PANDORA setup. Finally, the sensitivity of the measurement was evaluated through a virtual experimental run, starting from the simulated plasma-dependent γ-rate maps. These results indicate that laboratory ECR plasmas in compact traps provide suitable environments for β-decay studies of ⁷Be, with the estimated duration of experimental runs required to reach 3σ significance level being few hours, which prospectively makes PANDORA a powerful tool to investigate the decay rate under different thermodynamic conditions and related charge state distributions. Full article

Background: Diacerein, a prodrug of Rhein, is commonly prescribed for the management of joint disorders, specifically osteoarthritis. This study aimed to develop and validate an LC-MS/MS method to quantify Rhein and its major metabolites, Rhein-G1 and Rhein-G2, in plasma samples. Method: An ACE C18 column was used for chromatographic separation with a mobile phase comprising ammonium acetate at a concentration of 1.0 mM and acetonitrile. Detection was achieved using a Sciex 4000 Q-Trap LC-MS/MS, operated in negative ion mode with multiple reaction monitoring (MRM). Results: The analytical results indicated that the lower limit of quantification (LLOQ) for Rhein and its glucuronides was 7.81 nM. Precision was consistently below 9.14%, while accuracy remained within the acceptable range of 80.1–104.2%. We also verified the method’s matrix effect recovery and stability variance, which were less than 12.60% and 10.37%, respectively. The pharmacokinetic study demonstrated that diacerein is swiftly metabolized into Rhein, and then Rhein subsequently undergoes glucuronidation, forming detectable concentrations of Rhein-G1 and Rhein-G2 in plasma. Conclusions: This new LC-MS/MS method proved to be both sensitive and selective, allowing for pharmacokinetic studies in rats. Full article

Background: Chronic atrophic gastritis precancerous lesions (PL-CAG) are characterized by the atrophy of gastric mucosal glands, often accompanied by intestinal metaplasia or dysplasia. Timely intervention and treatment can effectively reverse its malignant progression and prevent the onset of gastric cancer. Bombyx Batryticatus (BB) exhibits a range of pharmacological effects, including anticoagulation, antiepileptic properties, anticancer activity, and antibacterial effects. However, the pharmacological basis and mechanisms underlying BB’s efficacy in treating PL-CAG remain unclear. Methods: A three-factor modeling approach was implemented to develop a rat PL-CAG model, while the MNNG-induced PLGC (precancerous lesions of gastric cancer) cell model was served as a cell PL-CAG model. UPLC-QE-Orbitrap-MS/MS (Ultra performance liquid chromatography-quadrupole-electrostatic field orbital trap high-resolution mass spectrometry) was utilized to perform an in-depth analysis of the components in the plasma extract of BB. Leveraging network pharmacology, molecular docking analyses, and experimental validation, we initially elucidated the potential mechanisms through which BB mediates its therapeutic effects on PL-CAG at both in vivo and in vitro levels. Results: Prototype compounds of 42 blood-entering components were identified by UPLC-QE-Orbitrap-MS/MS analysis. Network pharmacology analysis and molecular docking studies indicate that the core targets are primarily enriched in the PI3K-Akt signaling pathway, and the key components, including Nepitrin, Quercetin 3-O-neohesperidoside, Rutin, and others, exhibited stable docking conformations with the first eleven pivotal targets. Both in vivo and in vitro experiments validated that BB may effectively treat PL-CAG via modulation of the PI3K-Akt signaling pathway. Conclusions: The therapeutic efficacy of BB in the management of PL-CAG may be achieved through the synergistic interaction of multiple components and targets, which may be more closely related to the inhibition of the PI3K/AKT signaling pathway. This approach will establish a solid experimental foundation and provide essential data for the clinical application of BB in treating PL-CAG, while also facilitating further research initiatives. Full article

Background and Objectives: The purpose of this study was to evaluate potential protective effects of suramin on inflammation, oxidative stress, and histopathological damage a rat model of acute colitis created with acetic acid. Materials and Methods: Wistar albino (male) rats were randomly assigned to three groups: control (n = 10), colitis + saline (n = 10), and colitis + suramin (n = 10). Rectal instillation of 4% acetic acid was used to induce acute colitis. Suramin (10 mg/kg/day) or saline was administered intraperitoneally for 15 days. Plasma concentrations of pentraxin 3 (PTX3), tumor necrosis factor-alpha (TNF-α), neutrophil extracellular traps (NETs), and malondialdehyde (MDA) were determined using enzyme-linked immunosorbent assay (ELISA) and spectrophotometric methods. In addition, vascular endothelial growth factor (VEGF) and TNF-α levels in colonic tissue were also measured. Histopathological evaluations were conducted using hematoxylin and eosin staining. Results: Significant increases in plasma and tissue inflammatory markers, oxidative stress parameters, and histopathological scores were observed when compared to control group; values were higher in colitis group. Suramin treatment significantly reduced plasma PTX3, TNF-α, NETs, and MDA levels, and colonic TNF-α and VEGF concentrations compared to the untreated colitis group. Histological analysis showed reduced epithelial injury and leukocyte presence in rats receiving suramin. Conclusions: Our findings demonstrate that suramin significantly attenuates inflammatory and oxidative damage in an experimental model of acute colitis. These results suggest that suramin may possess therapeutic potential in intestinal inflammation; however, this effect requires further support through advanced experimental and clinical studies. Full article

Despite significant advancements in medical and surgical care, the morbidity and mortality rates of neonates and infants undergoing congenital cardiac surgery remain high. To identify new pathomechanisms associated with postoperative organ dysfunction, extracellular vesicles (EVs) were isolated from plasma from neonates and infants with or without organ dysfunction at three different time points around congenital cardiac surgery, and the EV miRNA expression profiles in the plasma were analyzed. A clear distinction was observed between the organ dysfunction (OD) and non-organ dysfunction (NOD) groups based on their EV miRNA expression profiles. Apoptosis and proinflammatory pathways were consistently upregulated across all time points in the OD group. Complement and coagulation cascades unexpectedly displayed downregulation at the end of the surgery in the OD group, which was verified further at the proteomic level in an independent patient cohort. The neutrophil extracellular trap (NET) formation was enhanced in the OD group across all time points compared to that in the NOD group. As NETs are known to consume complement components, these observed events might be interconnected. A feature selection machine learning method identified miR-200b-5p, miR-4800-5p, miR-363-3p, and miR-483-5p as robustly linked to organ dysfunction following congenital cardiac surgery (accuracy score = 9; SD in accuracy = 0.3162). In conclusion, our study suggested that neonates and infants with postoperative organ dysfunction were associated with enhanced NET formation and complement consumption. Full article

The study explores the optical and transport properties of polycrystalline ZnO thin films prepared using reactive pulsed mid-frequency sputtering with RF electron cyclotron wave resonance (ECWR) plasma. This deposition method increases the ionization degree of sputtered particles, the dissociation of reactive gas and the plasma density of pulsed reactive magnetron plasma. Optical absorption spectra reveal a sharp Urbach edge, indicating low valence band disorder. Lattice disorder and deep defect concentration are more likely to occur in samples with higher roughness. PL analysis at low temperature reveals in all samples a relatively slow (μs) red emission band related to deep bulk defects. The fast (sub-ns), surface-related blue PL band was observed in some samples. Blue PL disappeared after annealing in air at 500 °C. Room temperature Hall effect measurements confirm n-type conductivity, though with relatively low mobility, suggesting defect-related scattering. Persistent photoconductivity was observed under UV illumination, indicating deep trap states affecting charge transport. These results highlight the impact of deposition and post-treatment on polycrystalline ZnO thin films, offering insights into optimizing their performance for optoelectronic applications, such as UV detectors and transparent conductive oxides. Full article

An innovative approach is reported for recovering Fe and Zn resources from hazardous zinc-bearing electric arc furnace dusts (ZBDs) in a sustainable manner. A combination of carbothermal and H₂ reduction were used to overcome challenges associated with the high temperatures of carbothermal reduction and the high costs/limited supplies of hydrogen. In-depth reduction studies were carried out using zinc-rich (17 wt.%), iron-poor (35 wt.%) ZBD; coke oven battery dry quenching dust (CDQD) was used as reductant. Briquettes were prepared by mixing ZBD and CDQD powders in a range of proportions; heat treatments were carried out in flowing H₂ gas at 700 °C–900 °C for 4 h. The reduced products were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and inductively coupled plasma (ICP). The Fe content of the reduced briquettes showed increases between 50 and 150%, depending on composition and reduction temperature; Zn, Pb, Cl, Na, K and S were completely absent. The gaseous elements were collected in cooled traps at the furnace outlet to recover metallic zinc and other phases. The volatile products collected at the outlet (900 °C) contained more than 70% zinc and 6% lead; small amounts of zinc were also present in the metallic phase. The processing temperatures were significantly lower in the combined approach as compared to 100% carbothermal reduction. While reducing energy consumption and limiting the generation of greenhouse gases, this approach has the potential for enhancing the reutilization of hazardous industrial wastes, resource recovery, and economic and environmental sustainability. Full article