Search Results (1,824)

This work aims to maximize the Hawking emission temperature arising in the optical analog model of the event horizon of an astrophysical black hole. A weak probe wave interacts with an intense ultrashort optical pulse via the Kerr effect in a photonic crystal fiber. This interaction causes the probe wave to experience an effective spacetime geometry characterized by the presence of an optical event horizon, where the analogous Hawking radiation effect arises. Here we refer to the simulated or classical version of the analog of Hawking radiation. This study considers four distinct types of photonic crystal fibers with anomalous dispersion curves that allow for maximizing the effect. Our first three numerical simulations indicate that a Hawking emission temperature of up to 361 K can be achieved with a photonic crystal fiber with two zero-dispersion wavelengths, while the emission temperature values in the original investigation are lower than 244 K. And in the fourth, we can see that we have a configuration in which the temperature can be improved up to 1027 K. Moreover, these results also emphasize the feasibility of using analog models to test the quantum effects of gravity, such as Hawking radiation produced by typical black holes, whose magnitude is far below the temperature of the cosmic microwave background (2.7 K). Full article

Background/Objectives: Despite growing evidence on quantitative computed tomography (CT) analysis of coronary plaques and pericoronary adipose tissue (PCAT), their association with myocardial perfusion (MP) in patients with first acute myocardial infarction (AMI) with obstructive coronary artery disease (MICAD) and non-obstructive coronary arteries (MINOCA) remain unclear. The aim of this study was to assess the relationship between quantitative CT coronary plaque components and PCAT characteristics with MP, myocardial blood flow (MBF) and coronary flow reserve (CFR) obtained by dynamic single-photon emission computed tomography (SPECT) in patients with AMI. Methods: Patients with a first episode of AMI were included in the study. All patients underwent coronary CT angiography with quantitative assessment of plaque volume (PV) and burden (PB), as well as PCAT volume and attenuation. Dynamic SPECT was performed on cadmium–zinc–telluride gamma-camera for quantitative assessment of MP parameters, stress and rest MBF, and CFR. Results: A total of 31 patients (median age 62 [56–70] years) were analyzed, including MICAD (n = 21) and MINOCA (n = 10). MICAD patients had significantly higher total PV and PB, mainly due to non-calcified and fibrofatty components (p < 0.05), while low-attenuation (LAP) and calcified plaques (CP) did not differ between groups. PCAT volumes were higher in MICAD (p < 0.05), whereas PCAT attenuation showed no differences. Dynamic SPECT revealed lower stress MBF and CFR in MICAD (p < 0.05). Correlation analysis showed positive associations of PV and PB with MP summed stress and rest scores, except LAP or CP; PB was negatively associated with MBF. In addition, PCAT volume correlated negatively with stress and rest MBF and CFR, as well as PCAT attenuation correlated positively with stress-induced MP abnormalities. Conclusions: Patients with MICAD demonstrated a greater extent of atherosclerosis and larger PCAT volume compared with MINOCA. Moreover, PCAT volume demonstrated inverse associations with MBF and CFR, indicating a potential link between PCAT characteristics and microvascular dysfunction. Full article

Environmental pollution is becoming increasingly unpredictable over time due to its complexity, given the number of new chemicals produced annually and the constantly changing environmental conditions. Regulation has yet to keep pace with the rapid changes posed by chemical mixtures, especially in the Global South. Understanding the potential outcomes of co-exposure to multiple compounds can be challenging, even for professionals with a background in sustainability and mixture toxicity, due to the complexity of the issue. Some tools have been developed to tackle this uncertainty like the Species Sensitivity Distribution curve (SSD), the Adverse Outcome Pathways (AOP), and the Mixture Assessment Factor (MAF). This study aims to bridge the gap between knowledge generated in the field of mixture toxicity and regulatory practices by proposing sustainable management practices at the local scale, particularly for countries in the Global South. The proposed framework is called GlORIES and comprises the following measures. The first proposed step is to describe the chemicals used in industries or identified in existing environmental studies and/or monitoring campaigns on a watershed basis. Having a watchlist of compounds and organisms present in the region, and by generating a regionalized SSD, it is possible to use models such as AOPs to try to predict which compounds could potentially interact and thus generate a correcting factor, such as a MAF. A MAF could then be incorporated into regulations to further protect the environment by reducing the concentration of the compound in the mixture. Including local communities in reporting human and environmental health alterations could be a key to identifying the possible harmful emissions. It is proposed that watershed management committees be established to integrate all stakeholders and promote workshops organized by academia, industry, regulatory agencies, and civil society, leveraging existing structures to conserve energy in the process. The proposed framework can improve the sustainability of the process and the knowledge flow from academia to regulatory bodies, increasing the efficacy of the chosen water quality thresholds by adapting to real-life scenarios. Full article

Background and Objectives: Difficulties in language production and comprehension constitute clinical symptoms characterizing patients diagnosed with Primary Progressive Aphasia (PPA). Thorough assessment of language domains can detect specific deficits commonly observed in different PPA variants, but brief and practical instruments capable of screening for language impairment are lacking. The present study aimed to examine the ability of the Mini Linguistic State Examination (MLSE) to distinguish between healthy individuals and PPA patients, as well as to differentiate among PPA subtypes, within Greek clinical practice. Materials and Methods: Τhe Mini Linguistic State Examination (MLSE), a 15-min detailed examination of different language domains, was administered to a group of clinically diagnosed PPA patients and a group of healthy participants. In addition, PPA patients completed a neuropsychological test battery assessing memory, language, executive, and visuospatial functions. Patterns of patients’ brain perfusion were also explored with single-photon emission computed tomography. Results: Comparisons between PPA patients and healthy controls revealed significant differences across all MLSE domains (all p < 0.001), and receiver operating characteristic analyses demonstrated excellent diagnostic accuracy, with AUC values exceeding 0.90 across language domains and perfect classification for the total MLSE score (AUC = 1.00, p < 0.001). Conclusions: These findings indicate that the MLSE is able to detect distinct patterns of deficits and to provide a comprehensive overview of patients’ linguistic profiles, supporting its clinical utility and diagnostic potential for differentiating PPA variants. Full article

Background/Objectives: Tinnitus is a complex auditory phenomenon with multifactorial origins, often involving both peripheral and central auditory pathways. Given the multifactorial nature of tinnitus, this review specifically focuses on the auditory brainstem as it represents the first central relay for auditory input and a key site of abnormal synchrony and central gain, which may generate or modulate tinnitus even when peripheral hearing appears normal. Several studies suggest a potential role of brainstem dysfunction in its pathogenesis, even among patients with normal hearing thresholds. Although the physiopathological data provide evidence for the role of brainstem in the generation and magnification of tinnitus, the diagnostic tools are still unclear. This systematic review aimed to investigate the diagnostic relevance of brainstem-level abnormalities in individuals with tinnitus. Methods: Following PRISMA guidelines, a literature search was conducted using PubMed, Scopus, and Web of Science from January 2000 to June 2025. Studies were included if they addressed the diagnostic relationship between tinnitus and brainstem involvement. Data on auditory brainstem response (ABR), otoacoustic emissions (used to differentiate peripheral from central auditory abnormalities), neuroimaging, and electrophysiological markers were extracted. Results: Twenty studies were included. Most used ABR as a diagnostic tool, revealing significant amplitude and latency alterations in tinnitus patients compared to controls, particularly in wave V and V/I amplitude ratios. Imaging studies supported altered brainstem–cortical connectivity and localized changes in inferior colliculus (IC) activity. Additional techniques, such as middle-latency evoked potentials and gap-in-noise detection, showed potential but lacked consistent clinical utility. Conclusions: Evidence suggests that brainstem dysfunction may contribute to tinnitus generation or persistence. ABR and advanced imaging represent specific diagnostic tools, though standardization and high-quality studies are still needed to improve clinical applicability. Full article

Black smoke emitted from diesel vehicles contains substantial amounts of hazardous substances. With the increasing annual levels of such emissions, there is growing concern over their detrimental effects on both the environment and human health. Therefore, it is imperative to strengthen the supervision and control of black smoke emissions. An effective approach is to analyze the smoke emission status of vehicles. Conventional object detection models often exhibit limitations in detecting black smoke, including challenges related to multi-scale target sizes, complex backgrounds, and insufficient localization accuracy. To address these issues, this study proposes a multi-dimensional detection algorithm. First, a multi-scale feature extraction method was introduced by replacing the conventional C2F module with a mechanism that employs parallel convolutional kernels of varying sizes. This design enables the extraction of features at different receptive fields, significantly improving the capability to capture black smoke patterns. To further enhance the network’s performance, a four-layer adaptive feature fusion detection head was proposed. This component dynamically adjusts the fusion weights assigned to each feature layer, thereby leveraging the unique advantages of different hierarchical representations. Additionally, to improve localization accuracy affected by the highly irregular shapes of black smoke edges, the Inner-IoU loss function was incorporated. This loss effectively alleviates the oversensitivity of CIoU to bounding box regression near image boundaries. Experiments conducted on a custom dataset, named Smoke-X, demonstrated that the proposed algorithm achieves a 4.8% increase in precision, a 5.9% improvement in recall, and a 5.6% gain in mAP50, compared to baseline methods. These improvements indicate that the model exhibits stronger adaptability to complex environments, suggesting considerable practical value for real-world applications. Full article

Background/Objectives: Oral squamous cell carcinoma (OSCC) carries a risk of late metastasis not only in advanced stages but also in early stages. In this study, we built and tested radiomics-based machine learning (ML) models for predicting the risk of metastasis from early OSCC on ¹⁸F-FDG positron emission tomography (PET). Methods: Patients diagnosed with T1 or T2 squamous cell carcinoma who underwent a preoperative ¹⁸F-FDG PET-CT examination at a single institution between 2016 and December 2022 were included in this retrospective study. The presence or absence of late cervical lymph node metastasis was confirmed for all patients. Among the radiomics features extracted from the images, we selected those that were useful for predicting late metastasis and used them to create ML models. We then verified the prediction accuracy of the models. Results: A total of 109 subjects were included, of which 31 had late lymph node metastasis and 78 were without metastasis. The most accurate ML model created using radiomics features selected from the subject cases had an area under the curve of 0.977 and accuracy of 87.5%. Conclusions: We confirmed that ML models using radiomics features extracted from PET images can be useful for predicting late metastasis in patients with early-stage OSCC. Full article

Background: This paper develops a novel, interdisciplinary framework for optimizing high-speed rail (HSR) freight logistics hubs in the Ottawa–Quebec City corridor, addressing critical gaps in geospatial mismatches, static optimization limitations, and narrow sustainability scopes found in the existing literature. Methods: The research methodology integrates a hybrid graph neural network-reinforcement learning (GNN-RL) architecture that encodes 412 nodes into a dynamic graph with adaptive edge weights, fractal accessibility (α = 1.78) derived from fractional calculus (α = 0.75) to model non-linear urban growth patterns, and a multi-criteria sustainability evaluation framework embedding shadow pricing for externalities. Methodologically, the framework is validated through global sensitivity analysis and comparative testing against classical optimization models using real-world geospatial, operational, and economic datasets from the corridor. Results: Key findings demonstrate the framework’s superiority. Empirical results show an obvious reduction in emissions and lower logistics costs compared to classical models, with Pareto-optimal hubs identified. These hubs achieve the most GDP coverage of the corridor, reconciling economic efficiency with environmental resilience and social equity. Conclusions: This research establishes a replicable methodology for mid-latitude freight corridors, advancing low-carbon logistics through the integration of GNN-RL optimization, fractal spatial analysis, and sustainability assessment—bridging economic viability, environmental decarbonization, and social equity in HSR freight network design. Full article

This study investigates the accumulation, influencing factors, sources, and health risks of eight potential toxic elements (PTEs) in soils from the central–southern Shandong Peninsula, a region characterized by a high geological background and intensive human activities. Concentrations of Cr, Cd, Cu, Ni, Pb, Zn, As, and Hg were analyzed in 19,484 topsoil samples. The results showed that Cr, Cu, and Ni levels exceeded national background values, primarily linked to basalt distribution. Utilizing positive matrix factorization (PMF), spatial analysis, and comparative assessment, four primary sources were identified: natural sources (36.79%), combined traffic and agricultural activities (34.20%), coal combustion (17.32%), and industrial emissions (11.69%). A health risk assessment indicated that while non-carcinogenic risk was within the acceptable limits for the general population, it exceeded the threshold for children in 2.53% of cases, with As from coal combustion being the predominant contributor. These findings provide a critical theoretical basis for implementing targeted, source-oriented control strategies to mitigate PTE pollution in areas where high geological background and anthropogenic activities intersect. Full article

Background: Amyloid positron emission tomography (PET) has been proposed as a tool to monitor myelination in multiple sclerosis (MS). We present baseline results from an ongoing prospective study, which is the first to include both early and standard phases of amyloid PET in patients with newly diagnosed MS. Methods: The prospective study includes patients with newly diagnosed MS (January 2023–February 2024). Clinical evaluation includes neurological disability (EDSS) and neuropsychological assessment. Brain MRI, early [¹⁸F]florbetaben (FBB) PET (eFBB; 0–5, 0–10 min post-injection), and standard FBB PET (sFBB; 90 min post-injection) were acquired. Normal-appearing white matter (NAWM) and damaged white matter (DWM) in MRI were segmented and co-registered with PET images. Results are presented as standardized uptake values (SUV), with the ratio using cerebellum as the reference region (SUVR) and the percentage of change between the DWM and NAWM. Results: Twenty patients were included (35.05 ± 10.72 years; 75% women). Both eFBB and sFBB acquisitions showed significantly lower SUVRmax and SUVRmean, and higher SUVRmin in the DWM compared to NAWM (p < 0.001) in all patients. SUV parameters in both DWM and NAWM from eFBB and sFBB PET correlated with the number of relapses and EDSS (r = −0.454 and r = −0.446, respectively; p < 0.05). Additionally, SUVR values in the DWM during eFBB correlated with cognitive impairment (SDMT; r = −0.516, p < 0.01), fatigue (MFIS-5; r = −0.450, p < 0.05), and quality of life (EQ-5D; r = −0.490, p < 0.05). Conclusions: Quantitative analysis of dual-phase FBB PET demonstrates differential uptake between DWM and NAWM, which is probably associated with demyelination and neurodegeneration. These preliminary findings suggest that amyloid PET may have predictive value for disease activity and progression, supporting its potential as a biomarker in MS. Follow-up data from this study are needed to support the baseline results. Full article

The aim of this study was to rigorously quantify and analyse the concentrations of atmospheric pollutants (PM₁₀, PM_2.5, SO₂, NO₂, CO, H₂S, and O₃) emitted by artisanal brick kilns in Juliaca City, Peru. The AERMOD dispersion model and a network of low-cost sensors (LCSs) were employed to characterise air quality at specific receptor sites. A georeferenced inventory of kiln operations was created to determine their parameters and operational intensity, providing a foundation for estimating emission factors and rates. Data were obtained from the United States Environmental Protection Agency (EPA) and supplemented with locally gathered meteorological records, which were processed for integration into the AERMOD model. The findings revealed that brick kilns are a principal source of atmospheric pollution in the region, with carbon monoxide (CO) emissions being especially pronounced. The LCSs facilitated the identification of pollutant concentrations at various locations and enabled the quantification of the specific contribution of brick production to ambient aerosol levels. Comparative assessments determined that these sources account for approximately 85% of CO emissions within the study area, underscoring a significant adverse impact on air quality and public health. Background pollutant levels, emission rates, spatial distributions, and concentration patterns were analysed within the assessment zones, resulting in solid model performance. These results provide a sound scientific basis for the formulation and implementation of targeted environmental mitigation policies in urban areas and the outskirts of Juliaca. Full article

Background: Permanent cancer resolution requires a complete immunological response with generation of memory against malignant cells. Immunogenic cell death (ICD) achieves this by coupling cell death with the emission of damage-associated molecular patterns (DAMPs). Current cancer treatments immunosuppress the host; thus, new alternatives are needed. Ganoderma species produce anticancer triterpenoids (GTs); however, their mechanism remains unclear. Objective: This systematic review aims to provide insights into GTs’ pharmacodynamics and assess hypothetical ICD potential. Methods: Web of Science and PubMed databases were consulted following PRISMA guidelines. Studies from inception until 2024, reporting molecular changes associated with GTs’ anticancer effects, were considered. Nonhuman models were excluded. GTs and GTs-ICD converging molecular targets were listed and submitted to Cytoscape’s stringApp to construct protein interaction networks. Topological and enrichment analysis were performed. Results: A total of 204 articles were found, and 69 remained after screening. Overall anticancer effects include loss of mitochondrial membrane potential, DNA and RNA damage, autophagy, cell cycle arrest, and leukocyte activation. 136 molecular targets of GTs were identified; upregulated proteins include CHOP, PERK, p-eIF2α, and HSP70, a key DAMP. GTs and ICD share 24 molecular targets. GO:BP and KEGG enrichment analysis suggest that GTs’ anticancer effects are related to stress response, cell death regulation, and PD-L1/PD-1 checkpoint inhibition. GT-ICD enrichment converges on endoplasmic reticulum stress, unfolded protein response, and organelle membrane perforation. Conclusions: GTs exhibit polypharmacological anticancer effects, including anti-immunosuppression, upregulation of ICD-adjacent machinery, and even an increase in HSP. However, further studies are required to confirm a proper causal link between GTs’ cancer cell treatment and DAMP emission. Full article

Background/Objectives: The role of α-synuclein (α-syn) in the pathogenesis of Parkinson’s disease (PD) or neurodegenerative diseases such as Lewy body dementia (LBD) and multiple system atrophy (MSA) is commonly accepted. Through different physiological dysfunctions, abnormal forms of α-syn are generated. These abnormal aggregates accumulate and alter pre- and postsynaptic transmission, in particular that of dopamine. Thus, the development of a diagnostic biomarker of synucleinopathies remains crucial and challenging. The development of an α-syn positron emission tomography (PET) radiopharmaceutical may be suitable to early diagnose and stratify patients, follow up disease progression, and evaluate future therapies. Methods: To develop a selective α-syn PET tracer, we synthesized an original series based on alkynyl(aza)indoles. Fifteen final ligands were synthesized bearing indoles or azaindoles from one side of the alkyne and a substituted phenyl ring for the opposite side of the alkyne. The final ligands were tested to determine Ki and/or Kd toward α-syn, tau, and Aβ. Results: The SAR showed that the indole series exhibited moderate to low affinity for α-syn and, moreover, lower Ki toward Aβ and tau (i.e., compound 39, Ki_(αsyn) 21.7 nM, Ki_(Aβ) 64.4 nM, Ki_(Tau) 27.6 nM), highlighting the low potency of these series to afford an α-syn tracer. The introduction of a nitrogen on the different positions of the phenyl to obtain the corresponding azaindoles resulted for most of the compounds in better affinity for α-syn and selectivity towards Aβ compared to the indole analogs (i.e., compound 43, Ki_(αsyn) 4.7 nM, Ki_(Aβ) 24.4 nM, and Ki_(Tau) 4.61 nM). A fluorinated azaindole derivative was prepared with a view to obtaining a ¹⁸F tracer and exhibited the highest affinity for α-syn but without selectivity against tau and Aβ. The radiosynthesis of [¹⁸F]45 was performed in a two-step procedure starting from the tosylated and protected precursor. [¹⁸F]45 was obtained in 85 ± 5 min with a radiochemical yield of 32 ± 3%. Molar activity, determined from a calibration with stable 45, was around 130 GBq/µmole. The dynamic PET imaging showed that [¹⁸F]45 was able to cross the blood–brain barrier, but non-specific uptake was observed, confirming the in vitro results. Conclusions: Although promising nanomolar affinity for the target, the new tracer showed mainly non-specific in vivo uptake in the rat brain, indicating that further pharmacomodulations on the azaindole series are required. Full article

Background: Reducing agricultural carbon emissions can enhance agricultural resilience and promote sustainable agricultural development. Although prior research has examined how agricultural new-quality productive forces (ANQP) reshape factor allocation, technology adoption, and production efficiency, their implications for agricultural carbon emissions remain insufficiently studied. Objective: To quantify the impact of ANQP on agricultural carbon emissions, assess regional heterogeneity across the east, central, and west, between grain and non-grain areas, between the Yangtze River Economic Belt and other regions, and across different levels of fiscal support, and to identify an efficiency-based transmission mechanism. Materials and Methods: A panel of 30 Chinese provinces for 2012–2022 is analyzed using province and year fixed effects. Results: ANPQ significantly reduce agricultural carbon emissions. The effect is stronger in western provinces, in non-grain areas, within the Yangtze River Economic Belt, and where fiscal support is higher, and weaker in eastern and low-support regions. Trade-offs between yield stabilization and emission reduction emerge in the central region and in major grain-producing areas. Mechanism results indicate that ANQP lowers emissions primarily by improving agricultural production efficiency measured by total factor productivity. Full article

Background: In addition to clinical examinations, confirmatory investigations are frequently performed to determine brain death (BD). Among other perfusion tests, brain perfusion scintigraphy (BPS) has been shown to be a reliable tool for the detection of brain circulatory arrest, particularly in cases with inconclusive clinical status or potential pharmacological interactions. Methods: Evaluation for brain death included standardized clinical examinations by two experienced neuro-intensive medicine specialists, followed by ancillary brain perfusion tests. BPS with the lipophilic tracer ^99mTc-hexamethylpropyleneamine oxime (HMPAO) was performed according to a standardized protocol. Imaging results, additional confirmatory test results, as well as clinical parameters were prospectively recorded. Results: BPS was performed in 30 patients (18 male, 12 female; median age 55.5 years, range 0.1–79.8 years). Eight patients underwent decompressive craniectomy (DC) prior to BD evaluation, three patients were supported by veno-arterial extracorporeal membrane oxygenation (vaECMO), and one patient by a left ventricular assist device (LVAD). The median interval between the initial brain-damaging event and BPS was 4.0 days (range 1–18 days). BPS demonstrated brain perfusion cessation in all patients. A concomitant single-photon emission computed tomography (SPECT) was required in one patient. There were no technical failures requiring a re-examination. Conclusions: BPS is a feasible, safe, and technically robust confirmatory test in BD diagnosis. BPS yielded unambiguous results, particularly in cases with inconclusive results of other ancillary tests, in neonates, young children and patients after DC. It is applicable to patients supported by LVAD and vaECMO. Full article