Search Results (3,917)

This study provides a comprehensive assessment of 12 metal(loid)s in the muscle tissue of the commercially vital shrimp, Penaeus semisulcatus, from four stations (Bozyazi, Silifke, Karatas, and Iskenderun) along the Northeastern Mediterranean. Metal concentrations were evaluated separately for males and females, utilizing Estimated Weekly Intake (EWI), Target Hazard Quotient (THQ), Carcinogenic Risk (CR), and Selenium Health Benefit Value (HBV_Se) indices. While the species is generally safe for consumption across the region, a striking, localized bioaccumulation of Chromium (Cr) was identified specifically in Iskenderun Bay, where male shrimps exhibited concentrations (1.209 mg/kg wet weight) approximately 10-fold higher than females, highlighting a sex-specific sensitivity likely linked to metabolic and physiological differences. By adopting a precautionary risk assessment framework—considering the region’s intense industrial profile—this localized spike resulted in a Total Carcinogenic Risk (∑CR = 5.15 × 10⁻⁴) for this group, exceeding the priority threshold. Furthermore, widespread Lead (Pb) contamination was detected across all stations, with several samples surpassing EU maximum levels (0.50 mg/kg). Regarding Arsenic (As), while high total concentrations led to THQ values > 1 across the regional gradient, this was characterized as a conservative modeling artifact rather than a physiological threat, as Arsenic in crustaceans is predominantly in the non-toxic organic form. Conversely, any potential risk from Mercury (Hg) was conclusively mitigated by an overwhelming molar excess of Selenium (Se) at all locations, confirmed by consistently positive HBV_Se values (0.312–0.658). In conclusion, our findings demonstrate that seafood safety is conditional and region-specific. The study underscores that localized contamination “hotspots” can be easily masked by non-sex-specific sampling and emphasizes the necessity of moving beyond simplistic risk models by incorporating selenium-mercury antagonism and precautionary risk assumptions for industrial pollutants. Full article

Background: Pancreatic trauma (PT) in children is rare and associated with significant morbidity. The optimal form of management—operative versus non-operative—remains controversial, particularly in the presence of acute post-traumatic peripancreatic fluid collection, which may later evolve into pancreatic pseudocysts. Isolated pancreatic injuries without associated organ damage are uncommon and pose diagnostic and therapeutic challenges. Case Presentation: We report a 5-year-old boy who sustained an isolated grade IB blunt pancreatic head contusion following blunt abdominal trauma after falling onto a wooden fence. He presented with epigastric pain, repeated emesis, and an abdominal wall bruise. Initial ultrasound (US) findings were subtle; however, serial imaging and contrast-enhanced computed tomography (CECT) revealed focal contusion of the pancreatic head/uncinate process with a small peripancreatic fluid collection. Pancreatic enzymes were markedly elevated, with peak serum lipase reaching approximately 6579 U/L. The child remained hemodynamically stable and was managed conservatively with bowel rest, intravenous fluids, octreotide, proton-pump inhibition, pancreatic enzyme replacement therapy (PERT), and antibiotics. Serial US demonstrated the dynamic evolution of an acute peripancreatic fluid collection (APFC) (~2 cm), which remained stable without complications. Clinical and biochemical parameters gradually improved, and no invasive intervention was required. The patient was discharged on hospital day 16 with planned outpatient imaging follow-up. Conclusions: This case demonstrates that isolated pediatric pancreatic contusions complicated by small, evolving peripancreatic fluid collections can be safely managed non-operatively in hemodynamically stable patients. Serial ultrasound plays a key role in monitoring lesion evolution and guiding management decisions. In accordance with current pediatric trauma guidelines, careful observation with structured follow-up may prevent unnecessary invasive interventions while achieving excellent clinical outcomes. Full article

Dengue virus (DENV) is a mosquito-borne RNA virus that causes serious illness in humans, ranging from mild fever to severe clinical manifestations, with dengue virus type 2 (DENV-2) being the most virulent among its four serotypes. Despite extensive research, no specific antiviral therapy is currently available, making the host-directed method an appealing therapeutic approach. Evidence shows that DENV manipulates host kinase-driven phosphorylation pathways to control viral pathogenesis. Using the kinase–substrate phosphomotif approach, we predicted phosphorylation sites across the DENV proteome and their potential human kinases. The predicted kinase–substrate interactions were systematically integrated with DENV-2-induced human phosphoproteome datasets, protein–protein interactions, and experimentally-validated viral phosphosites. The therapeutic relevance of the identified host kinases was corroborated by the impact of their inhibitors on DENV-2 infection. Among the 359 potential human kinases predicted to phosphorylate DENV-2 proteins, based on human phosphoproteome and kinase–viral protein interaction analyses, CDK9 emerged as a central hub kinase. Molecular docking analyses further revealed that the host kinases CDK9, EEF2K, HASPIN, and TNNI3K form stable interactions with the viral capsid and NS5 proteins. Additionally, a conservation analysis suggested that the predicted phosphorylation sites are evolutionarily conserved across DENV-2 strains. Computational prediction tools supported the predicted kinase–substrate interactions, underscoring the role of host kinases as key regulators of DENV infection, which may act as potential therapeutic targets. This study highlights the interplay between dengue viral and host proteins, providing insights into host-directed therapeutic strategies for DENV-2 infection and their potential to address the current lack of effective antiviral interventions. Full article

Heavy metals in agricultural systems pose a significant challenge to food security, especially in regions with long-term intensive land use. While the Pannonian Plain represents Croatia’s primary breadbasket, accounting for a significant portion of the nation’s cereal production, data on the soil-to-grain transfer of heavy metals and the associated human exposure risk are limited. The objective of this study was (i) to determine the concentrations of arsenic (As), cadmium (Cd), and lead (Pb) in agricultural soils and corresponding grains (wheat, barley, and maize) across four principal counties within the Pannonian region of Croatia; (ii) to evaluate the soil-to-grain transfer factors that varied regionally and among cereal types; and (iii) to assess the potential non-carcinogenic health risks for both adults and children highlighting differences in exposure due to body weight and consumption patterns. Soil and cereal grain samples were collected in 2019 and 2020, and metal concentrations were determined by ICP-MS after microwave acid digestion. The transfer of metals from soil to grain was estimated using the transfer factor (TF), while exposure assessment was conducted by calculating the estimated daily intake (EDI), hazard quotient (HQ), and hazard index (HI). Due to the nonlinear distribution of the data and the lack of strictly matched soil and grain samples, median metal concentrations pooled across all studied regions were used for exposure assessment. For As, a conservative approach was applied, assuming that 50% of the total As is in inorganic form. Additionally, a probabilistic risk assessment using Monte Carlo simulations was conducted to account for variability in body weight and cereal intake, providing a more comprehensive evaluation of potential exposure. The results showed differences in metal accumulation among cereal species, with wheat and barley tending to accumulate more Cd than maize, while As and Pb concentrations in grains were low for all crops studied. Although soil metal concentrations in Međimurje County were generally low, elevated TF values for As and Pb were observed, indicating enhanced soil-to-plant transfer under specific local soil conditions. In contrast, high soil metal concentrations in Slavonski Brod–Posavina County were associated with low TF values, suggesting limited bioavailability and restricted transfer to cereal grains. Both deterministic and probabilistic assessments indicated that the HQ and HI for adults and children were below 1, suggesting low non-carcinogenic risk from cereal consumption. These findings highlight pronounced regional and crop-specific differences in soil-to-plant metal transfer and confirm that low soil contamination does not necessarily imply low transfer potential, emphasizing the importance of integrated soil–plant–grain monitoring for food safety assessment. Full article

Linear vector fields on Lie groups constitute a fundamental class of dynamical systems, as their flows are one-parameter subgroups of automorphisms and their infinitesimal behavior is entirely determined by derivations of the Lie algebra. When a Lie group is endowed with a Hamiltonian-type geometric structure, a natural problem is to determine whether such linear dynamics admit a global variational realization, and how such realizations can be interpreted in terms of reduced models of fluid motion. In the even-dimensional case, where the Lie group carries a symplectic structure, we establish a complete global criterion for the existence of Hamiltonians generating linear symplectic vector fields. The problem reduces to a single global obstruction: the de Rham cohomology class of the 1-form ${\iota }_{\mathcal{X}}\omega$. Thus, every linear symplectic vector field on a simply connected Lie group is globally Hamiltonian, and when the obstruction vanishes, we provide an explicit constructive procedure to recover the Hamiltonian. On the affine group ${\mathrm{Aff}}^{+}\left(1\right)$, this yields a fully explicit, finite-dimensional Hamiltonian model of a 1D ideal fluid with affine symmetries. We then treat odd-dimensional Lie groups, where symplectic geometry is unavailable. Using contact geometry as the canonical replacement, we prove a Hamiltonian lifting theorem ensuring the existence and uniqueness of the associated dynamics. The Reeb vector field appears as a distinguished vertical direction resolving the ambiguities of degenerate Hamiltonian systems. On the Heisenberg group $H_3$, this gives a fully explicit contact Hamiltonian model of an effective non-conservative fluid mode. Finally, we interpret symplectic and contact theories within a unified geometric framework and discuss their relevance to geometric formulations of ideal (symplectic) and effective (contact) fluid equations on Lie groups. Full article

The FAR1-RELATED SEQUENCES (FRS) gene family plays a crucial role in light signaling, stress adaptation, and developmental regulation processes directly impacting crop growth and yield. This study identified 49 GmFRS genes unevenly distributed across 17 soybean chromosomes, phylogenetically classified into seven subgroups (I–VII), with subgroup VII forming an exclusive evolutionary subgroup alongside orthologs from Poaceae and Solanaceae. Members within each subfamily share conserved motif compositions and similar exon/intron structures. Gene duplication and selection pressure analyses revealed that the GmFRS family expanded primarily through WGD duplication events and then non-syntenic gene duplication, with all members evolving under purifying selection. Promoter analysis identified abundant cis-acting elements implicated in responses to light, phytohormones and other abiotic stimuli. Organ-/tissue-specific expression profiling demonstrated organ-preferential expression for family members, with the highest transcript levels observed in flowers (32.7%). Quantitative real-time PCR (qRT-PCR) analysis further indicated that the expression of most GmFRS genes is light-inducible and exhibits marked sensitivity to far-red light. This study may elucidate soybean FRS family functions in light signaling, development, and stress adaptation, while also providing foundational insights for molecular breeding in Glycine max. Full article

The increasing impact of climate change and resource scarcity demands energy-efficient and resource-conserving manufacturing strategies. Metal forming offers substantial potential for lightweight construction and material efficiency. Forming-induced ductile damage, particularly void nucleation and growth, is often neglected in component design. Industrial practice still relies mainly on macroscopic mechanical properties and safety factors, while microstructural damage evolution and its influence on fatigue performance are largely disregarded. This study investigates load-path-dependent fatigue behavior and damage mechanisms using axial and combined axial–torsional fatigue tests. Particular attention is given to the phase shift d between axial and torsional loading, which strongly affects fatigue life. The results indicate that axial loading dominates damage evolution, while load path interactions significantly change fatigue performance. A phase shift of d = 90° resulted in a significant increase in the number of cycles to failure, N_f, for different total strain amplitudes with the same rotational angle amplitude of θ = 10°. These findings highlight the importance of considering load-path-sensitive stress states in fatigue assessment of formed components. Fractographic analyses, AI-assisted 3D reconstruction, and confocal laser scanning microscopy support the experimental results. Full article

Sturgeon stock enhancement is one of the key approaches for the conservation of sturgeon species and the restoration of aquatic biological resources. In Kazakhstan, these activities are mainly concentrated in the Caspian and Irtysh river basins, where broodstocks are formed from natural populations for artificial reproduction and annual replenishment of natural stocks. Such programs also provide an opportunity to assess the biological status of populations and evaluate the level of differentiation between sterlet populations inhabiting the Irtysh and Caspian basins. This study analyzed morphological similarities and differences between sterlet (Acipenser ruthenus) populations from the Irtysh and Zhayik rivers. Morphometric analysis revealed clear morphological differentiation between the studied populations. The most pronounced differences were observed in head width parameters (HC and BC), as well as in the SO and R indices, whereas measurements related to total body length showed minimal variation between samples (about 1%). Statistically significant differences (t-test, p ≤ 0.05) were identified for several morphometric indices, including the length-to-height ratio (L/H), head size index (C/L), and relative body height index (H/L). Considering these differences is important when planning stocking activities to ensure successful adaptation, maintain genetic diversity, and minimize the risk of degradation of local sterlet populations. Full article

The spotted seal (Phoca largha) is an ice-associated pinniped in the Northwest Pacific and is a subject of conservation concern under increasing environmental and anthropogenic pressures; however, genomic studies have been constrained by the absence of a high-quality reference genome. Here, we present a near-telomere-to-telomere (near-T2T), gap-free genome assembly of P. largha spanning 2.39 Gb and comprising 16 chromosome-length sequences, with a scaffold N50 of 184.39 Mb and high completeness (99.34% complete BUSCOs). Compared with the previous chromosome-level assembly, the new genome improves contiguity and gene-space completeness. Comparative analyses across 20 carnivoran species resolve P. largha as sister to Phoca vitulina with an estimated divergence time of ~2.1 Ma. Branch-site positive-selection analyses and gene-family evolution analyses identify lineage-associated changes, and enrichment results motivate focused investigation of integument-related gene families. Targeted analyses of keratin (KRT) and matrix metalloproteinase (MMP) families reveal contrasting chromosomal organisation and evolutionary dynamics: KRTs form large chromosomal clusters with broadly conserved synteny across Carnivora but lineage-dependent remodelling within clusters, whereas MMPs are dispersed and display largely conserved orthologous correspondence. This high-quality genome provides a high-quality resource for pinniped comparative genomics and for elucidating the genomic architecture of skin and fur adaptation. Full article

Urbanization significantly reshapes urban form, affecting the spatial and quantitative dynamics of urban land use under carbon constraints. However, the role of macro-scale urban form in guiding low-carbon urban expansion remains underexplored. Our study introduces an integrated Cellular Automata (CA) model to simulate urban land use patterns with regard to the low-carbon goal, focusing on urban form optimization. The model employs a top-down strategy to adjust future urban land demand by balancing urban development needs with carbon emission (CE) reduction targets. The adjusted demand is then used to optimize urban form parameters (i.e., the inverse S-shaped function) to predict future urban land patterns and allocate land increments within concentric rings. Subsequently, a bottom-up strategy incorporating carbon sequestration (CS) conservation is applied to refine urban land conversion. The CA model integrates a maximum probability transformation rule to allocate urban land efficiently. We used the model to simulate urban land use patterns under four scenarios (i.e., Low-carbon Urban Development Scenario (L-UDS), Top-up Urban Development Scenario (T-UDS), Bottom-up Urban Development Scenario (B-UDS), and inverse S-shaped constraint Urban Development Scenario (S-UDS)) for the Changsha–Zhuzhou–Xiangtan (CZX) urban agglomeration in 2035. Results show that the proposed model effectively reconciles the conflict between rapid urbanization and urban carbon management strategies, as evidenced by a 31.25% reduction in carbon emissions in the L-UDS and T-UDS relative to the S-UDS and B-UDS. Furthermore, urban form constraints promote the development of compact and dense urban structures, advancing sustainable urban development goals. This study not only proposes a simulation model capable of effectively promoting compact urban development at the theoretical level, but its findings also offer actionable policy insights for China to address urban sprawl and actively advance low-carbon urban development. Full article

Group II introns are catalytic RNAs that combine self-splicing ribozyme activity with mobility and have played major roles in shaping organellar genome evolution. In green macroalgae of the genus Ulva, organellar genomes are highly compact, yet they harbor unusually diverse and dynamic repertoires of group II introns. To understand how organellar group II introns diversify and persist within compact organellar genomes, we performed a comparative analysis of mitochondrial and chloroplast group II introns across Ulva, integrating secondary structure reconstruction, intron occurrence patterns, and phylogenetic inference based on both conserved intron RNA regions and intron-encoded proteins (IEPs), including reverse transcriptase/maturase (RT/M) and LAGLIDADG homing endonuclease (LHE). A total of 168 mitochondrial and 123 chloroplast introns were identified and classified into 32 families belonging to seven major subgroups (IIA1-RT/M, IIA2-RT/M, IIB1-RT/M, IIB1-LHE, IIB2-RT/M, IIB2-LHE, and IIB-like). Most intron families retain the canonical six-domain architecture (DI–DVI), but four mitochondrial IIA families display a seven-domain configuration generated by the lineage-specific insertion of an additional stem-loop structure (DIIIa). Phylogenetic analyses revealed a high degree of congruence, supporting persistent coevolution between RNA scaffolds and their IEPs. Notably, the LHE-encoding families were scattered across distinct IIB lineages instead of forming a single clade, suggesting that at least two independent invasion events occurred within the IIB1 and IIB2 lineages. Analysis of intron occurrence frequency revealed an evolutionary continuum ranging from structurally intact and broadly distributed families to lineage-specific families exhibiting progressive scaffold degeneration, with the chloroplast infA-62 family representing a stably inherited lineage maintained through vertical transmission. These results suggest that organellar group II introns in Ulva evolve through coordinated scaffold remodeling, enzymatic replacement, and differential distribution patterns across genomic compartments, highlighting Ulva organellar genomes as a valuable comparative model for investigating the long-term evolution of mobile ribozymes within compact genomic environments. Full article

This work places the invariant $d{s}^2$ at the center of the gravitational interaction, interpreting it not as a purely geometric object but as the differential of proper time, endowed with direct physical meaning. Starting from the extension of Fermat’s principle to massive particles—namely, the requirement that freely falling bodies follow trajectories that extremize proper time, which for timelike motion corresponds to a local maximum—and invoking the universality of Galilean free fall, we derive the form of $d{s}^2$ in a static gravitational field. Lorentz invariance then provides the natural framework to extend this result to systems involving moving matter. The invariant derived through this procedure matches the weak-field limit of General Relativity formulated in the harmonic gauge. Within this linearized regime, we show that the structure of the theory already contains the seeds of its nonlinear completion: any dynamically consistent extension to strong gravitational fields necessarily involves the Ricci tensor. From this viewpoint, Einstein’s field equations appear not as a postulated geometric law but as the unique covariant closure required to ensure energy–momentum conservation and the self-consistency of the gravitational interaction. Full article

Against the backdrop of a gradual shift in the focus of cultural heritage (CH) conservation and utilization toward the integrated system formed by CH and its surrounding environment as well as regional systems, research on the coordinated protection of nature and culture to promote regional high-quality development has become a new trend. However, systematic summaries of the spatial–temporal distribution of CH in cross-regional typical geomorphic units at the river basin scale and their correlation with the natural environment remain insufficient. This study takes 387 Cultural Relics Protection Units in the Three Gorges of the Yangtze River (the Three Gorges region) as the research objects, utilizing GIS spatial analysis technology to examine the impact of the natural environment on CH across different periods and types. The theory of time-depth is introduced to reveal the layering mechanisms and underlying cultural logics. Coupled with the Minimum Cumulative Resistance (MCR) model, this study constructs a cultural corridor network and proposes spatial planning strategies. The findings are as follows: (1) The absolute core area for the distribution of CH across all periods remains the gentle slope zone near the river, characterized by elevations below 500 m, slopes within 25°, and distances from water systems within 1 km. However, the adaptive scope exhibits a diachronic evolution from core accumulation to peripheral expansion. (2) Different types of CH exhibited distinct natural adaptation strategies and vertical accumulation. Settlement Sites in the Before Qin Dynasty Period formed the foundational layer of survival rationality, while Ordinary Tombs in the Qin–Yuan Dynasty Period reinforced sedentism. Ancient Architecture in the Ming–Qing Dynasty Period underwent a transformation from “adapting to nature” to “reconstructing nature” as a product of environmental construction. Modern and Contemporary Significant Historical Sites and Representative Buildings in the After Qing Dynasty Period are characterized by a ruptured insertion on steep slopes, inscribing revolutionary memory onto space. The main stream of the Yangtze River serves as the core area of continuous deposition, while the extremely steep slopes form a distinctive stratigraphic accumulation of precipitous terrain. (3) Based on these distribution patterns, the study further proposes a spatial framework for CH called “One Corridor, Three Wings.” This framework uses the main stream of the Yangtze River as the spatial–temporal axis, linking the four core overlapping nodes of Fengjie, Wushan, Badong, and Xiling, supplemented by three secondary cultural clusters of the red heritage sites in southern Badong, the ancient town along the Daning River in Wushan, and the fortress sites in the Xiling–Yiling area. This research not only reveals the evolutionary path of CH in the Three Gorges region, but also provides a scientific basis for the systematic conservation and differentiated utilization of regional CH. Furthermore, it serves as a planning foundation and strategic reference for planning the Yangtze River National Cultural Park, as well as for the integrated preservation and utilization of river basin CH and linear CH with the aim of coordinated natural and cultural conservation. Full article

The travertine formed through the precipitation of supersaturated calcium carbonate from geothermal or surface waters due to CO₂ degassing, evaporation, and biological activities not only exhibits remarkable landscape value but also holds significant scientific importance in geological research. Current conservation efforts face critical challenges including travertine degradation, increased algal biomass accumulation, and progressive marshification processes. The study focused on how Vallisneria natans (V. natans) and Ceratophyllum demersum (C. demersum) affected travertine deposition. Analyzing the physical and chemical parameters, phase structure, crystal morphology, and microbial community in the aquatic environment, it was observed that under conditions of low c (Ca²⁺) concentration in solution (≤100 mg L⁻¹), both species significantly increased the rate of travertine deposition. The effect of plant biomass was species-specific: V. natans showed the highest promotion at 70 g L⁻¹, while C. demersum performed effectively at moderate biomass levels (140 and 280 g L⁻¹). Specifically, C. demersum exhibited enhanced photosynthetic activity, elevated pH, increased dissolved oxygen (DO) content and more epibiotic microorganisms, with higher levels of Aeromonas compared to V. natans. Therefore, C. demersum demonstrated a greater capacity for travertine deposition. However, the culture environment with elevated c (Ca²⁺) ≥ 500 mg L⁻¹ or higher biomass levels (420 g L⁻¹) impeded the stable growth of submerged plants and exerted a stress effect on them, hindering travertine deposition. The morphology of travertine crystals promoted by the two submerged macrophytes was distinct. In the V. natans treatment, the crystals were square and elongated, whereas in the C. demersum treatment, they were spheraragonite, droplet-like, and petal-shaped. This study reveals the mechanisms by which submerged macrophytes promote travertine deposition and provides new insights for adopting nature-based ecological restoration strategies to sustainably maintain travertine landscapes. By leveraging the promoting effects of submerged macrophytes, travertine deposition and the aquatic environment were improved while reducing energy and chemical inputs. Such biological regulation approaches help synergistically achieve the dual objectives of geological heritage conservation and ecosystem health restoration. Full article

Cuticular proteins (CPs)—key components of the insect exoskeleton—not only regulate development but also serve as structural barriers that enhance resistance against environmental stressors. This study identified CP gene families in Apis mellifera and analyzed their expression patterns during the worker capped brood development stages from mature larva to pre-eclosion. Using a comprehensive genome-wide bioinformatic approach, we identified 85 CP genes in A. mellifera which comprise six families: CPR (n = 43), CPAPs (n = 27), CPF (n = 2), Tweedle (n = 2), CPLCP (n = 8) and Apidermin (n = 3). Analysis of CP gene evolutionary relationship revealed that each CP family forms a distinct, relatively independent clade. Domain and motif analyses confirmed that all CPR members harbor a conserved Chitin_Bind_4 domain, consistent with CPR family structures in other taxa. Additionally, CPAP members possess one or three Chitin-binding Peritrophin-A domain (CBM_14), CPF members possess a conserved Pupal cuticle protein C1 domain (Cuticle_3), and Tweedle members contain a conserved domain of unknown function (DUF243). In addition, the analysis found no conserved domain within the CPLCP and Apidermin families. RNA-seq data revealed dynamic expression patterns of AmCPs during pupal development, with each gene family displaying a relatively characteristic temporal profile. Quantitative PCR validation of eight highly expressed CPR genes at 9 days post-capping confirmed the RNA-seq results. This work provides a comprehensive bioinformatic characterization and transcriptional analysis of CP genes in A. mellifera, offering a foundation for future functional studies on cuticle formation and identifying candidate genes potentially involved in cuticle development in honeybees. This work relies on transcriptomic data and in silico analyses. All proposed biological roles are hypothetical and require experimental validation. Full article