Contrary to naive cosmological expectations, all evidence suggests that the universe contains an abundance of matter over antimatter. This article reviews the currently popular scenario in which testable physics, present in the standard model of electroweak interactions and its modest extensions, is responsible for this fundamental cosmological datum. A pedagogical explanation of the motivations and physics behind electroweak baryogenesis is provided, and analytical approaches, numerical studies, up to date developments and open questions in the field are also discussed.
The leakage detection of oil and gas is very important for the safe operation of pipelines. The existing working condition recognition methods have limitations in processing and capturing complex multi-category leakage signal characteristics. In order to improve the accuracy of oil and gas pipeline leakage detection, a multi-scale convolutional neural network-Transformer (MSCNN-Transformer)-based oil and gas pipeline leakage condition recognition method is proposed. Firstly, in order to capture the global information and nonlinear characteristics of the time series signal, STFT is used to generate the time-frequency image. Furthermore, in order to enrich the feature information from different dimensions, the one-dimensional signal and the two-dimensional time-frequency image are sampled by multi-scale convolution, and the global relationship is established by combining the multi-head attention mechanism of the Transformer module. Finally, the leakage signal is accurately identified by fusing features and classifiers. The experimental results show that the proposed method shows high performance on the GPLA-12 data set, and the recognition accuracy is 96.02%. Compared with other leakage signal recognition methods, the proposed method has obvious advantages.
André Guaraci DeVito-Moraes, Isabela Souza Vardasca, Miguel Peñarrocha-Diago
et al.
This study investigates the mechanical and optical properties of monolithic zirconia used in dentistry, focusing on how different concentrations of yttrium oxide and varied sintering times affect the material. A critical trade-off in ceramics has been reported in the literature, in which increased crystalline content (like in zirconia) leads to higher mechanical strength but lower aesthetic translucency. However, detailed information on this trade-off process for different types of zirconia is lacking. A total of seven types of zirconia varying in yttria content (3 mol% to 5 mol%) were tested across four sintering protocols available in a laboratory zirconia sintering device: Slow (12 h), Standard (8 h), Fast (3.5 h), and Ultrafast (1.15 h). The primary findings indicate that while a higher yttria concentration correlates with lower flexural strength and high translucency, the sintering time generally did not compromise mechanical strength or color variation across most samples. Nevertheless, the Fast and Ultrafast protocols did significantly reduce the translucency of zirconia with a high concentration of yttrium oxide.
Raquel Ciérvide, Roberto Manchón, Daniela Angel
et al.
BACKGROUND: This study evaluates practices and preferences in treating intact brain metastases with stereotactic-radiosurgery (SRS) among members of the SEOR-SRS_SBRT working group, focusing on clinical protocols, equipment usage, and treatment parameters. MATERIALS AND METHODS: A survey conducted via Google Forms targeted 149 group members, with responses collected from one representative per institution between April and May 2024. Respondents included radiation oncologists from Mexico, Argentina, Portugal, and Spain, and data analysis covered demographics, equipment, treatment protocols, immobilization techniques, dose schedules, image-guided radiation therapy (IGRT), and prescription criteria. RESULTS: Out of 149 members, 28 institutions responded. Most participants (64.5%) had over 10 years of experience. Single-fraction-SRS was practiced by 64.5%, while fractionated SRS-SRT was used by 96.8%. Linear accelerators (C-Linac) were the primary equipment (86.7%). Specific protocols for brain metastases were reported by 80%. SRS was preferred for 1–3 metastases (93.3%), while whole-brain radiation therapy (WBRT) was used for > 10 metastases (70%). Considering the type of stereotactic localization, frameless systems were employed in 69% while rigid-frames were used in 31% of cases. The most common immobilization technique was a reinforced mask (50%). Planning computed tomography (CT)/magnetic resonance imaging (MRI) slice thickness ≤ 2 mm was standard, and automatic registration was applied in 69%. Doses of 21–23 Gy were common for lesions < 1 cm, while < 20 Gy was typical for 2–3 cm lesions. Margins for single-fraction SRS were 1 mm in 50% of cases. IGRT verification used cone-beam CT (64.5%) and surface-guided radiation therapy (35.5%). CONCLUSION: The findings reveal variability in SRS practice, particularly in immobilization, dose prescriptions, and IGRT methods, emphasizing the need for standardized guidelines to optimize patient outcomes and adapt treatments to institutional resources and patient-specific factors.
Neoplasms. Tumors. Oncology. Including cancer and carcinogens, Medical physics. Medical radiology. Nuclear medicine
Intergalactic wandering stars (IWSs) within 10 Mpc remain a poorly explored area of astronomy. Such stars, if they exist, are supposed to be wandering objects as they are not bound by the gravitational potential of any galaxy. We set out to conduct dedicated studies to unravel such a wandering stellar population. As the first paper of the series, in the present work, we model the distance distribution and luminosity function of IWSs formed via the Hills mechanism of the Galactic central massive black hole (GCMBH). We implement a numerical simulation to generate IWSs, taking the ejection history of the GCMBH and the stellar evolution process into consideration, and present their luminosity function in the distance range of 200 kpc–10 Mpc. Our results suggest that a few hundred thousand IWSs have been generated by the GCMBH via the Hills mechanism in the past 14 billion yr. These IWSs have an apparent magnitude peaking at 30–35 mag in the Sloan Digital Sky Survey r band, which are hard to detect. However, a few thousand of them at the bright end are detectable by upcoming wide-field deep surveys, such as the China Space Station Telescope and the Vera Rubin Observatory. The forthcoming discovery of such a wandering stellar population will open the door for a precise understanding of the matter constitution of the nearby intergalactic space and the dynamical history of galaxies in the local Universe.
Guang Li PhD, Victoria Yu PhD, Kaitlyn Ryan BS
et al.
Purpose To improve the setup reproducibility of neck curvature using real-time optical surface imaging (OSI) guidance on 2 regions of interest (ROIs) to infer cervical spine (c-spine) curvature for surface-guided radiotherapy (SGRT) of head-and-neck (HN) and c-spine cancer. Methods A novel SGRT setup approach was designed to reproduce neck curvature with 2 ROIs: upper-chest ROI and open-face ROI. It was hypothesized that the neck curvature could be reproduced if both ROIs were aligned within ±3 mm/2˚ tolerance. This was tested prospectively in 7 volunteers using real-time 3D-OSI guidance and lateral 2D-photography verification after the 3D and 2D references were captured from the initial conventional setup. Real-time SGRT was performed to align chest-ROI and face-ROI, and the longitudinal distance between them was adjustable using a head-support slider. Verification of neck curvature anteriorly and posteriorly was achieved by overlaying edge-extracted lateral pictures. Retrospectively, the relationship between anterior surface and spinal canal alignment was checked in 11 patients using their simulation CT (simCT) and setup cone-beam CT (CBCT). After the anterior surface was rigidly aligned, the spinal canal alignment was checked and quantified using the mean-distance-to-agreement (MDA) and DICE similarity index, and surface-to-spine correlation was calculated. Results The reproducibility of neck curvatures using the 2xROI SGRT setup is verified and the mean neck-outline-matching difference is within ±2 mm in lateral photographic overlays. The chest-ROI alignment takes 110 ± 58 s and the face-ROI takes 60 ± 35 s. When the anterior body surface is aligned (MDA = 1.1 ± 0.6 mm, DICE = 0.96 ± 0.02,) the internal spinal canal is also aligned (MDA = 1.0 ± 0.3 mm, DICE = 0.84 ± 0.04) in 11 patients. The surface-to-spine correlation is c = 0.90 (MDA) and c = 0.85 (DICE). Conclusion This study demonstrates the feasibility of the novel 2-ROI SGRT setup technique to achieve reproducible neck and c-spine curvature regardless of neck visibility and availability as ROI. Staff training is needed to adopt this unconventional SGRT technique to improve patient setup.
Neoplasms. Tumors. Oncology. Including cancer and carcinogens
Kaori Sánchez-Carrillo, David Quintanar-Guerrero, Miguel José-Yacamán
et al.
L-lysine functionalized gold nanoparticles (AuNPs-Lys) have been widely used for the detection of worldwide interest analytes. In this work, a colorimetric assay for the detection of the carcinogen aflatoxin B1 (AFB1) based on the aggregation of AuNPs-Lys in the presence of copper ions was developed. For this purpose, AuNPs were synthesized in citrate aqueous solution, functionalized, and further characterized by UV–Vis, fluorescence, Fourier transform infrared spectroscopy (FTIR), nanoparticle tracking analysis (NTA), dynamic light scattering (DLS), and transmission electron microscopy (TEM). In general, AuNPS-Lys (~2.73 × 1011 particles) offered a clear colorimetric response in the presence of AFB1 and Cu2+ ions showing linearity in the range of 6.25 to 200 ng AFB1/mL, with a detection limit of 4.18 ng AFB1/mL via photometric inspection. Moreover, the performance of the proposed methodology was tested using the 991.31 AOAC official procedure based on monoclonal antibodies in maize samples artificially contaminated with AFB1. There was a good agreement between the measured AFB1 concentrations in both assays, the average recoveries for the colorimetric and immunoaffinity assays were between 91.2–98.4% and 96.0–99.2%, respectively. These results indicated that the colorimetric assay could be used as a rapid, eco-friendly, and cost-effective platform for the quantification of AFB1 in maize-based products.
Perhaps the most important aspect of symmetry in physics is the idea that a state does not need to have the same symmetries as the theory that describes it. This phenomenon is known as spontaneous symmetry breaking. In these lecture notes, starting from a careful definition of symmetry in physics, we introduce symmetry breaking and its consequences. Emphasis is placed on the physics of singular limits, showing the reality of symmetry breaking even in small-sized systems. Topics covered include Nambu-Goldstone modes, quantum corrections, phase transitions, topological defects and gauge fields. We provide many examples from both high energy and condensed matter physics. These notes are suitable for graduate students.
We review the nuclear astrophysics aspects of accreting neutron stars in X-ray binaries. We summarize open astrophysical questions in light of recent observations and their relation to the underlying nuclear physics. Recent progress in the understanding of the nuclear physics, especially of X-ray bursts, is also discussed.
The paper gives an introduction to the physics approach to social systems providing the main definitions and notions used in the modeling of these systems. The behavior of social systems is illustrated by several quite simple, typical models. The present part considers equilibrium systems. Nonequilibrium systems will be presented in the second part of the review. The style of the paper combines the features of a tutorial and a survey, which, from one side, makes it simpler to read for nonspecialists aiming to grasp the basics of social physics, and from the other side, describes several rather recent original models containing new ideas that could be of interest to experienced researchers in the field. The selection of the material is limited and motivated by the author’s research interests.
Two-dimensional (2D) semiconductors with intrinsic dipole show glorious prospects in the fields of nanoelectronics. Herein, the possible applications of single-layer GaInO3 in the realms of optoelectronics and piezoelectricity are investigated via the first-principles study. We find that single-layer GaInO3 exhibits a large vertical dipole moment and a direct bandgap (1.53 eV). Its transport mobility for electrons and holes both surpasses 2000 cm2·V−1·s−1. The effective separation of charge carriers for single-layer GaInO3 is confirmed by the strong inside electric field and the spatially isolated conduction band minimum (CBM) and valence band maximum (VBM). The allowed optical transition makes single-layer GaInO3 a hopeful candidate for optical absorbers and detectors. Finally, we also find that single-layer GaInO3 holds a prominently stronger out-of-plane piezoelectric effect than that of previous 2D materials and will play a big role in modern top-bottom gate technologies. In summary, this work proves that single-layer GaInO3 is a promising candidate for atomic-thick optoelectronic and piezoelectric devices.