Search Results (1,325)

Contemporary surveys in the search for extraterrestrial intelligence (SETI) typically make one-off “spot scans” across the sky to search planetary systems for narrow-band radio signals that would indicate the presence of intelligent life. Spot scans may span a duration of seconds to minutes in order to observe a large number of targets with limited resources, but such a strategy does not necessarily consider the timing of exactly when to listen for extraterrestrial signals. Several ideas for possible time markers were suggested in the first few decades of SETI, such as the use of recurrent supernovae, gamma ray bursts, or pulsars as a way of establishing directionality and attracting attention toward an extraterrestrial beacon. Civilizations in binary systems might even choose the points of periastron and apastron in its host system to send transmissions to other single-star civilizations. However, all of these timing considerations were developed prior to the age of exoplanets, which enables a more detailed assessment of targets suitable for SETI. This paper suggests SETI strategies for circumbinary and circumprimary planets based upon the timing of orbital events in such systems. Events such as orbital extremes could represent a logical time marker for extraterrestrial civilizations to transmit, if they desire to be detected. Likewise, a transiting binary pair with inhabited planets around each star could yield maximum detectability of leakage radiation when both stars eclipse within our field of view. As planets in binary systems continue to be discovered, limited-duration SETI surveys should selectively target such systems based upon the occurrence of reasonable time markers. Full article

Fluid flow prediction in clastic heterogeneous reservoirs is a universal issue, especially when diagenetic development supplants structural and depositional controls. We consider this issue in the Middle Miocene Belayim Formation of the Gulf of Suez, a principal syn-rift reservoir where extreme, diagenetically induced pore system heterogeneity thwarts production. Although fault compartmentalization is understood as creating first-order traps, sub-seismic diagenetic controls on permeability anisotropy and reservoir within these traps are not restricted. This study uses a comprehensive set of petrophysical logs (ray gamma, resistivity, density, neutrons, sonic) of four key wells in the western field of Tawila (Tw-1, Tw-3, TW-4, TN-1). We apply an integrated workflow that explicitly derives permeability from petrophysical logs and populates it within a seismically defined structural framework. This study assesses diagenetic controls over reservoir permeability and fluid flow. It has the following primary objectives: (1) to characterize complicated diagenetic assemblage utilizing sophisticated petrophysical crossplots; (2) to quantify the role of shale distribution morphologies in affecting porosity effectiveness utilizing the Thomas–Stieber model; (3) to define hydraulic flow units (HFUs) based on pore throat geometry; and (4) to synthesize these observations within a predictive 3D reservoir model. This multiparadigm methodology, involving M-N crossplotting, Thomas–Stieber modeling, and saturation analysis, deconstructs Tawila West field reservoir complexity. Diagenesis that has the potential to destroy or create reservoir quality, namely the general occlusion of pore throats by dispersed, authigenic clays (e.g., illite) and anhydrite cement filling pores, is discovered to be the dominant control of fluid flow, defining seven unique hydraulic flow units (HFUs) bisecting the individual stratigraphic units. We show that reservoir units with comparable depositional porosity display order-of-magnitude permeability variation (e.g., >100 mD versus <1 mD) because of this diagenetic alteration, primarily via pore throat clogging resulting from widespread authigenic illite and pore occupation anhydrite cement, as quantitatively exemplified by our HFU characterization. A 3D model depicts a definitive NW-SE trend towards greater shale volume and degrading reservoir quality, explaining mysterious dry holes on structurally valid highs. Critically, these diagenetic superimpressions can replace the influence of structural geometry on reservoir performance. Therefore, we determine that a paradigm shift from a highly structured control model to an integrated petrophysical and mineralogical approach is needed. Sweet spot prediction relies upon predicting diagenetic facies distribution as a control over permeability anisotropy. Full article

Additive manufacturing via selective laser sintering (SLS) enables the rapid production of geometrically complex polyamide 12 (PA12) components. However, conventional pointwise analysis techniques often overlook the full depth of continuous experimental datasets, thus limiting the interpretation of structure–function relationships that are essential to high-performance design. This study employs functional data analysis (FDA) to elucidate the microstructural, chemical, thermal, and mechanical behaviours of SLS-fabricated PA12, focusing on the effects of build orientation (horizontal, transverse, vertical) and wall thickness (2.0–3.0 mm). The samples were produced via a commercial SLS platform and characterised via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and tensile testing. The FDA was applied to raw, normalised, and first derivative datasets via Python’s Scikit-FDA package, increasing the sensitivity to latent material variations. The findings demonstrate that the build orientation has a marked influence on the crystallinity and mechanical performance: horizontal builds yield narrower gamma-phase XRD peaks, greater structural order, and enhanced tensile properties, whereas vertical builds exhibit broader peak dispersion and greater thermal sensitivity. The wall thickness effects were minor, with only isolated flux-related anomalies. The FTIR spectra confirmed the consistent chemical stability across all the conditions. The FDA successfully identified subtle transitions and anisotropies that eluded traditional methods, underscoring its methodological strength for advanced polymer characterisation. These insights offer practical guidance for refining SLS process parameters and improving predictive design strategies in polymer-based additive manufacturing. Full article

Background/Objectives: Sentinel lymph node biopsy (SLNB) is currently the standard approach for axillary staging in breast cancer. Conventional techniques are radioisotope-based (Technetium-99m, Tc99m) and remain widely used, but novel tracers like Indocyanine Green (ICG) fluorescence provide potential advantages regarding feasibility and logistics. Methods: We conducted a prospective, observational study including 476 female patients diagnosed with primary invasive breast cancer who underwent SLNB at the Institute of Oncology “Prof. Dr. I. Chiricuță”, Cluj-Napoca, Romania, between January 2022 and May 2025. Clinical, surgical, and pathological variables were systematically extracted. SLNB was performed using either Tc99m or ICG, according to institutional protocols. Comparative analyses were performed to evaluate sentinel node characteristics, histopathological parameters, and positive surgical margins predictors. Results: The median age was 60 years (IQR: 52–69). Breast-conserving surgery (BCS) was performed in 77.9% of cases, while mastectomy was performed in 22.1%. Sentinel lymph node positivity was reported in 25.6% of cases, with no significant differences in the number of excised or metastatic nodes between Tc99m and ICG (mean nodes: 3.23 vs. 3.20, p = 0.860; mean positive nodes: 0.35 vs. 0.36, p = 0.897). Histologically, invasive carcinoma NST was predominant (90.1%), and surgical margins were negative in 96.8% of patients, with all margin-positive cases occurring following BCS. No pathological markers (grade, Ki67, TILs, DCIS extent) predicted margin status or nodal involvement. Notably, younger age correlated inversely with the extent of ductal carcinoma in situ (r = −0.21, p < 0.00001). Conclusions: Tc99m and ICG provided comparable diagnostic performance in performing SLNB, with equivalent rates of nodal detection and pathological yield. These findings support that ICG is a safe and effective alternative for routine axillary staging in breast cancer. Full article

Radiotherapy employs high-energy X-rays to precisely target tumor tissues while minimizing damage to the surrounding healthy structures. Although its clinical efficacy is well established, the immunomodulatory effects of ionizing radiation remain complex and context-dependent. This study investigated the biological effects of radiotherapeutic doses on immune cells by evaluating lymphocyte viability, phenotypic profiles, and cytokine expression levels. Peripheral blood mononuclear cells (PBMCs) were isolated from six healthy donors and irradiated with 0, 2, or 6 Gy using a 6 MV linear accelerator (LINAC). Dose validation with an ionization chamber demonstrated strong agreement between estimated and measured values (intraclass correlation coefficient = 1, 95% CI). Immune subsets, including T cells (CD3+), helper T cells (CD3+CD4+), cytotoxic T cells (CD3+CD8+), regulatory T cells (CD3+CD4+Foxp3+), and natural killer (CD3-CD56+) cells, along with intracellular cytokines interleukin-12 (IL-12) and interferon-gamma (IFN-γ), were analyzed via flow cytometry at multiple time points. The results showed a significant, dose-dependent decline in overall lymphocyte viability (p < 0.01) compared to control. Cytotoxic T cells were the most radiosensitive, followed by helper and regulatory T cells, while NK cells were the most radioresistant. IL-12 expression initially increased post-irradiation, while IFN-γ levels remained variable. These findings demonstrate that radiation induces distinct alterations in immune phenotypes and cytokine profiles, which may shape the immune response. Immune profiling following irradiation may therefore provide valuable insights for optimizing combination strategies that integrate radiotherapy and immunotherapy in cancer treatment. Full article

Gluons within the proton may accumulate near a critical momentum due to nonlinear QCD effects, leading to a gluon condensation. Surprisingly, the pion distribution predicted by this gluon distribution could answer two puzzles in astronomy and high-energy physics. During ultra-high-energy cosmic ray collisions, gluon condensation may abruptly produce a large number of low-momentum pions, whose electromagnetic decays have the typical broken power law. On the other hand, the Large Hadron Collider (LHC) shows weak but recognizable signs of gluon condensation, which had been mistaken for BEC pions. Symmetry is one of the fundamental laws in natural phenomena. Conservation of energy stems from time symmetry, which is one of the most central principles in nature. In this study, we reveal that the connection between the above two apparently unrelated phenomena can be fundamentally explained from the fundamental principle of conservation of energy, highlighting the deep connection and unifying role symmetry plays in physical processes. Full article

This study introduces the Normalized Difference Gamma Ray Index (NDGRI), a novel spectral composite derived from Sentinel 2 imagery for mapping elevated natural gamma radiation in semi-arid and arid basins. We hypothesized that water-sensitive spectral indices correlate with gamma-ray hotspots in arid regions of Mongolia, where natural radionuclide distribution is influenced by hydrological processes. Leveraging historical car-borne gamma spectrometry data collected in 2008 across the Sainshand and Zuunbayan uranium project areas, we evaluated twelve spectral bands and five established moisture-sensitive indices against radiation heatmaps in Naarst and Zuunbayan. Using Pearson and Spearman correlations alongside two percentile-based overlap metrics, indices were weighted to yield a composite performance score. The best performing indices (MI—Moisture Index and NDSII_1—Normalized Difference Snow and Ice Index) guided the derivation of ten new ND constructs incorporating SWIR bands (B11, B12) and visible bands (B4, B8A). The top performer, NDGRI = (B4 − B12)/(B4 + B12) achieved a precision of 62.8% for detecting high gamma-radiation areas and outperformed benchmarks of other indices. We established climatological screening criteria to ensure NDGRI reliability. Validation at two independent sites (Erdene, Khuvsgul) using 2008 airborne gamma ray heatmaps yielded 76.41% and 85.55% spatial overlap accuracy, respectively. Our results demonstrate that NDGRI effectively delineates gamma radiation hotspots where moisture-controlled spectral contrasts prevail. The index’s stringent acquisition constraints, however, limit the temporal availability of usable scenes. NDGRI offers a rapid, cost-effective remote sensing tool to prioritize ground surveys in uranium prospective basins and may be adapted for other radiometric applications in semi-arid and arid regions. Full article

The accumulation of high levels of manganese ions complexed with small molecules has been proposed as a pivotal factor contributing to the extraordinary radiation resistance of Deinococcus radiodurans. However, the molecular mechanisms governing the manganese ion homeostasis remain elusive. In this study, we characterize the role of the MntABC transporter system for Mn ion accumulation in D. radiodurans. Its cellular membrane localization is unequivocally demonstrated through fluorescence labeling techniques. Mutation of the protein components of the MntABC led to a significant decrease in intracellular Mn ion accumulation, concomitant with impaired cellular growth, decreased resistance against hydrogen peroxide, and gamma-ray irradiation-induced oxidative stresses, indicating that the MntABC system plays an indispensable role in resistance of D. radiodurans to oxidative stresses. Protein structure modeling and molecular docking are employed to analyze the key active sites of the MntABC proteins and their intermolecular interactions. The results demonstrate that the MntABC system is essential for maintaining Mn ion homeostasis and the oxidative stress resistance of D. radiodurans. Full article

Kazakhstan holds the global leadership position in natural uranium mining. Nonetheless, the extraction and processing of radioactive ores has the potential to induce instances of radiological contamination. This study aimed to evaluate the radiological soil contamination at a former monazite, tin, and radioactive ore processing facility located in Ust-Kamenogorsk city. Pedestrian gamma–ray measurements revealed dose rates up to 1.00 µSv/h, significantly exceeding the natural background (0.16–0.18 µSv/h). The analysis of the 28 soil profiles demonstrated that deeper soil layers (below 60 cm) were significantly contaminated with radionuclides constituting production waste. Furthermore, the total activity in the superficial soil layer is in the range of 583–5275 Bq/kg (alpha emitters) and 641–1749 Bq/kg (beta radionuclides). The maximum of total radioactivity in the samples collected at the 80–100 cm layer was at the level of 22,482 Bq/kg (α-emitters) and 6845 Bq/kg for gross beta radiation. In consideration of the site’s proximity to public buildings, the calculated radiological hazard indices were calculated, revealing the potential danger for human health. The elevated excess lifetime cancer risk and annual gonadal dose equivalent obtained for the topsoil layer indicate a high level of radiological risk to the local population. The obtained results emphasise the necessity of developing rehabilitation strategies and long-term monitoring of the contaminated site, which is consistent with the global objectives of sustainable development in the field of environmental protection and public health. Full article

The Erlian Basin, an important research area for sandstone-type uranium deposit exploration in China, is affected by overburden layers, resulting in indistinct characteristics of uranium anomalies in airborne gamma-ray spectrometry (AGS). To harness the potential of AGS, it is imperative to develop effective verification methods that can identify the spatial relationship between weak uranium anomalies and deep uranium-rich geological bodies. This study presents a comprehensive investigation of geophysical and geochemical measurements conducted in four distinct areas. There is a significant positive correlation between the ground gamma spectrometry equivalent uranium (eU_GGS) content, soil radon concentration (C_Rn), geoelectrochemical uranium (U_GEC), and metal activity state uranium (U_MAS) content directly above and at the edges of uranium-rich geological bodies. When the buried depth of the uranium-rich geological body exceeds 100 m, the eU_GGS content above these deep uranium bodies increases by (0.4–1.2) × 10⁻⁶ g/g compared to background areas, while the C_Rn levels at the edges of these bodies increase by more than 5000 Bq/m³, which is 3–5 times higher than the regional average. Meanwhile, the U_GEC and U_MAS contents show sawtooth-like uranium peak anomalies on their profiles, and their peak-to-background ratio is greater than 5. The verification methods and corresponding interpretation indicators, namely GGS, C_Rn, GEC and MAS measurements, can quickly reveal the spatial relationship and provide a reliable basis for concealed uranium deposit exploration. Full article

Alveolar echinococcosis (AE) is a zoonotic disease caused by the larval form of the tapeworm Echinococcus multilocularis, which is considered one of the most dangerous parasites for humans. E. multilocularis infections are most frequently observed in forestry workers, farmers, hunters, berry harvesters, and workers employed in animal shelters. The subject of this study was a four-year follow-up profile of cytokines, including tumor necrosis factor alpha (TNFα), interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-4 (IL-4), and interleukin-10 (IL-10), in a patient with advanced liver alveolar echinococcosis and non-optimal antiparasitic treatment. Ultrasound, computed tomography (CT) of the abdomen, X-ray, CT of the chest, and magnetic resonance imaging (MRI) of the head were performed during the observation and treatment of the AE patient. After antiparasitic treatment was initiated, decreased activity of the gamma-glutamyl transpeptidase (GGTP), decreased serum concentrations of immunoglobulin E, C-reactive protein (CRP), and the pro-inflammatory cytokines TNFα, IL-1, and IL-6 were observed, as well as slightly increased levels of the anti-inflammatory cytokines (IL-4 and IL-10). Conclusions. During a four-year follow-up in a patient with advanced hepatic alveolar echinococcosis and non-optimal antiparasitic treatment, a decrease in proinflammatory cytokines (TNFα, IL-1β, IL-6) and a slight increase in anti-inflammatory cytokines (IL-4, IL-10) were detected. A better understanding of cytokine regulation in infectious diseases may be important to the development of new therapeutic strategies aimed at antiparasitic treatment. We suggest that broad initiatives (preferably at the local community level) should be implemented to raise awareness of the threat of alveolar echinococcosis and methods for avoiding E. multilocularis infection. Full article

The first detection of gravitational waves from the binary black merger GW150914 started the era of gravitational astronomy. The observation of the binary neutron star merger GW170817 and of its associated electromagnetic counterpart GRB 170817A started multi-messenger gravitational astronomy. This short review discusses the discovery of GW170817 and the follow-up of the electromagnetic counterpart, together with the broad range of results in astrophysics and fundamental physics, including the Gamma-Ray Burst field. The GW170817/GRB 170817A observation showed that binary neutron star mergers can explain at least a fraction of short Gamma-Ray Bursts. The optical and infrared evolution of the associated AT 2017gfo transient showed that binary neutron star mergers are sites of r-process nucleo-synthesis. The combination of gravitational and electromagnetic observations has been used to estimate the Hubble parameter, the speed of gravitational waves, and the equation of state of nuclear matter. The increasing sensitivity of interferometric detectors and the forthcoming operation of third generation detectors will lead to an improved statistics of binary neutron star mergers. Full article

We compare the observational properties of rotation-powered binary millisecond pulsars (BMSPs) in the Galactic Field with various companion types. First, BMSPs with diverse companion types exhibit different properties in the relation of binary orbital period versus companion mass, and in the spin period distribution of neutron stars (NSs), etc., implying multiple origins of BMSPs. Second, BMSPs with companions of CO/ONeMg white dwarfs (CO-BMSPs) show fewer sources than those with companions of Helium white dwarfs (He-BMSPs), which may result from the different evolutionary histories or accretion efficiencies in their progenitors. Third, BMSPs with main-sequence companions (MS-BMSPs) and ultra-light companions or planets (UL-BMSPs) are mostly eclipsing sources that are detected in both radio and $\gamma$-ray bands (i.e., radio+$\gamma$ sources), implying that they may be younger systems and share a faster average spin period and higher average accretion rate than CO-BMSPs/He-BMSPs. We propose that the predecessors of MS-BMSPs may share a short binary orbital distance with low-mass companion stars of $M_{\mathrm{c}}\sim 0.5$–$0.8{\mathrm{M}}_{\odot }$, which induces an efficient binary accretion process, and ultimately leaves a BMSP with a main-sequence companion due to the low efficiency of its hydrogen burning. Lastly, radio+$\gamma$ He-BMSPs share a faster average spin period of NSs than radio-only He-BMSPs. Meanwhile, these two groups of sources share similar companion mass distributions, implying the $\gamma$-ray evaporation effect may not obviously strip the companion mass of He-BMSPs during ∼0.3 Gyr, which may be due to the strong gravitational potential energy of the white dwarf companions. Full article

The high-redshift blazars are important cosmological probes for exploring the early universe and unraveling the fundamental emission processes and the structure of the active galactic nuclei. The high-energy GeV gamma-ray emissions of 38 high-redshift blazars (z > 2.5) observed by Fermi-LAT were analyzed. Along with the Archive multiwavelength data, we employ one-zone leptonic external Compton (EC) models to reproduce the spectral energy distributions (SEDs) of 38 sources. Both the external photons from the molecular torus (MT) and the broad-line region (BLR) are considered. We obtained the best-fitting parameters for describing the characteristics of the jets and accretion disks. The results indicate that high-redshift blazars exhibit higher $\gamma$-ray luminosities, energy densities, jet powers, kinetic powers, accretion disk luminosities, black hole (BH) masses, radiation efficiencies, and mass accretion rates compared to low-redshift blazars. For high-redshift blazars, the influence of the accretion rate on jet power appears to weaken, and in most cases, the jet power exceeds the total accretion power. We speculate that for high-redshift blazars, rapid accretion may lead to magnetic field saturation, thereby reducing the effectiveness of the Blandford–Payne (BP) process. Consequently, the Blandford–Znajek (BZ) process is likely to play a more dominant role in powering jets in high-redshift blazars compared to low-redshift blazars. Naturally, we acknowledge that selection effects cannot be fully eliminated. Full article

$\gamma$ Cas analogs is an enigmatic group of Be stars with unusually hard X-rays and an X-ray luminosity of ${10}^{31}$–${10}^{33}$erg $s^{-1}$, which is higher than a typical value for classical Be stars. The evolutionary status of these mysterious objects and the nature of their X-ray emission remains disputable. I suppose that our understanding of this mystery is in the detailed studies of their optical and X-ray variability on the various time scales from very short to very long. In the present paper the optical and X-ray spectral and photometric observations of these stars are reviewed. The contemporary assumptions on the mechanisms of X-ray radiation generation of $\gamma$ Cas analogs are discussed. It is concluded that the analysis of the binarity of $\gamma$ Cas analog helps to understand their inexplicable nature. Full article