Search Results (84)

Botulinum neurotoxins (BoNTs), among the most potent biological toxins, rely on co-produced nontoxic proteins to survive harsh gastrointestinal conditions and achieve efficient systemic dissemination after oral exposure. Recent structural and functional studies have revealed how BoNTs bind to the nontoxic non-hemagglutinin (NTNH) factors to engage in interactions with either OrfXs/P47 or hemagglutinins (HAs) components for systemic dissemination. This review synthesizes recent findings that elucidate the molecular basis of NTNH-specific anchoring to the HA70 triskelion-like element or to the host protease-activated form of OrfX2, thereby highlighting divergent pathways that enhance oral toxicity. We also discuss current perspectives on the molecular mechanisms through which BoNTs, in cooperation with associated nontoxic proteins, are absorbed from the intestine. Full article

This study presents an innovative and interdisciplinary didactic approach for teaching biodiversity to high school students, aiming to enhance basic learning skills and promoting deeper understanding of biological concepts. The designed educational proposal aims to support policy-driven collaboration between schools and botanical gardens within the framework of coordinated and long-term educational policies. The intervention was designed to cultivate both cognitive and metacognitive skills within three (3) didactic hours, offering a holistic learning experience through the study of Tulipa members used as an alluring model. A total of 168 Greek first- and second-grade high school students (on average 16 years old) participated in the study. Biodiversity was examined in a multidisciplinary fashion, focusing on species’ diversity (phenotypic), genetic-karyological diversity, and habitat diversity. The core components of the approach included: (a) the completion of a corresponding worksheet module, which effectively engaged students in the learning process using the 5E didactic model, and (b) a karyotype lab experiment using living Tulipa specimens. The learning process was evaluated through two questionnaires assessing the acquisition of scientific knowledge and behavioral outcomes. The results showed a positive impact on students’ understanding regarding the genetic material and biodiversity, with the karyotype experiment playing a key role in achieving high performance in both cognitive and affective learning objectives. Knowledge scores were higher in the second-grade students (53–73%) than in the first-grade students (44–69%) of high school, especially regarding concepts such as karyotype applications and biodiversity-ecosystem balance. The karyotype experiment positively correlated with both the evaluation of the intervention and the shifts in biodiversity beliefs (Pearson’s r = 0.649, 0.515; p < 0.05, respectively). The modeled inquiry-based approach with living tulips and karyotype experiments can help schools and botanic gardens counteract plant blindness by enhancing cognitive and affective learning outcomes within a limited instructional timeframe. Full article

This study investigated premixed NH₃ combustion in a closed circular duct using two-dimensional numerical simulations. By varying the equivalence ratio and the oxygen volume fraction from 21% to 30%, the evolution of flame morphology, flame propagation velocity, flame surface area, as well as the temporal variations in duct-averaged temperature and pressure were systematically examined. In addition, sensitivity analysis and reaction-pathway analysis based on a detailed chemical kinetic mechanism were performed to clarify the coupling between local chemical reactions and global flow dynamics. The results showed that the flame generally evolves through a sequence of hemispherical, finger-shaped, wall-attached skirt, and planar finger- and tulip-shaped structures. Well-developed tulip flames are mainly observed under conditions close to stoichiometric composition with moderate to elevated oxygen enrichment, corresponding to an intermediate overall reactivity. As the oxygen volume fraction increases from 21% to 30%, flame propagation becomes markedly faster. The tube-averaged temperature and the peak overpressure show an overall increasing trend. This increase in overpressure is most pronounced at equivalence ratios of 1.0–1.2. This study identifies hazardous parameter ranges in oxygen-enriched NH₃ combustion that are prone to producing strong tulip flames and high overpressure, providing useful guidance for explosion risk assessment and safety-oriented design of NH₃-fueled combustion systems. Full article

Background/Objectives: Land management practices strongly influence soil biochemical processes, yet conventional soil measurements often overlook dynamic small-molecule variation underlying nutrient cycling and microbial activity. This study aimed to evaluate whether MS¹-based untargeted metabolomics can resolve meaningful biochemical differences among soil systems under distinct land management practices. Methods: Soils from six land-use types—conventional cultivation, organic cultivation, pasture, white pine, tulip poplar, and hardwood forest—were analyzed using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). Multivariate analyses, including PLS-DA, were performed to evaluate metabolic variation across systems. Both identified metabolites and unknown spectral features (MSI Level 4) were assessed, and biosynthetic class assignment of unknown features was performed using NPClassifier. Results: Metabolic features revealed clear separation between land management systems, demonstrating distinct chemical fingerprints across ecosystems. While conventional elemental ratios (e.g., C/N) showed minimal differentiation, phosphorus-related stoichiometric ratios (C/P and N/P) displayed strong land-use-dependent differences. NPClassifier superclasses highlighted unique chemical patterns, with forest soils enriched in diverse secondary metabolites, cultivated soils characterized by simplified profiles, and pasture soils dominated by microbial membrane lipids and alkaloids. Conclusions: Untargeted MS¹-based metabolomics effectively distinguished soil systems under different land-use practices and revealed ecologically meaningful variation even without complete structural identification. This study demonstrates that an MS¹-only workflow leveraging unknown spectral features can robustly distinguish soil systems, underscoring their value in untargeted metabolomics analyses. Full article

The European Union air transport sector has been repeatedly exposed to major disruptions such as the 2008 financial crisis, the COVID-19 pandemic, the war in Ukraine, and volatile energy prices. Strengthening resilience has, therefore, become a strategic priority. This study examines how strategic energy investments—covering renewable energy, sustainable aviation fuels (SAFs), electrification, hydrogen technologies, and advanced infrastructure—contribute to the resilience of the EU air transport system. The methodology integrates both primary and secondary data from EU policy documents, ICAO and IATA databases, Eurostat, and national statistics. A multi-criteria evaluation was applied using four key performance indicators: emission reduction efficiency (ER), annual exposure index (AEI), investment performance index (IPI), and net present value (NPV). Projects were assessed through Simple Additive Weighting (SAW) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), complemented by sensitivity analysis. The results show that the Pioneer project delivers the strongest environmental and financial outcomes, ranking first in ER, AEI, and NPV. Hermes performs best in job creation and social impact, while BioOstrand achieves substantial absolute CO₂ reductions but lower cost efficiency. TULIPS shows limited effectiveness across all indicators. Sensitivity analysis confirmed that rankings remain robust under alternative weighting scenarios. The findings underscore that project design and alignment with resilience objectives matter more than investment size. Strategic energy investments should, therefore, be prioritized not only for decarbonization but also for their ability to reinforce both technological and socio-economic resilience, providing a reliable foundation for a sustainable and crisis-resistant EU air transport sector. Full article

The H7N9 influenza viruses, which are capable of causing severe respiratory syndrome in humans, were first discovered to infect humans in 2013 and continue to pose a persistent public health threat. Quail has been proposed as a potential intermediate host that may facilitate the emergence of novel reassorted influenza A viruses with the capacity to infect humans across species barriers; however, information on the biological characterization of quail H7N9 remains limited. In this study, we isolated and identified an avian H7N9 influenza virus from quails, designated as A/quail/Hebei/CH06-07/2018 (H7N9) and abbreviated as CH06-07, in Hebei, China. Phylogenetic analyses revealed that both the HA gene and the NA gene of CH06-07 were clustered in the Eurasian lineage. Furthermore, CH06-07 exhibited binding affinity for both α2,3-linked and α2,6-linked sialic acid receptors and demonstrated high pathogenicity in both quails and mice. Notably, transmission studies revealed that CH06-07 not only exhibited efficient inter-quail transmission and inter-guinea pig transmission but also demonstrated effective cross-species transmission. Importantly, infected quails and guinea pigs generated significant quantities of viral aerosols (≥18,998 ± 1672 copies per liter of air at 3 days post-infection), and infectious viruses were successfully recovered from environmental aerosols. These findings highlight the necessity for continuous surveillance of the prevalence of quail-origin H7N9 influenza A viruses in poultry populations due to their potential threat to human health. Full article

Tulipa auliekolica and Tulipa turgaica have been recently described as endangered species endemic to Kazakhstan, which require urgent conservation amid rising human impact and climate change. Biotechnology offers effective tools for conserving such rare species; however, species-specific in vitro protocols tailored to their biological traits remain largely unreported. This study aimed to develop an in vitro propagation protocol for these rare Tulipa species by investigating the effects of different temperature regimes and phytohormone treatments. We conducted a study on the in vitro propagation of two recently described species, T. auliekolica and T. turgaica. Species-specific temperature regimes for seed stratification were established. Maximum germination of T. auliekolica was achieved at alternating temperatures of 4/10 °C, and of T. turgaica at 10/20 °C. No seed germination from either species occurred at a constant temperature of 20 °C. Bulbs cultured on Murashige & Skoog (MS) medium supplemented with 90 g/L sucrose and the growth regulators mT (meta-topolin) and BAP (6-benzylaminopurine) were effective in stimulating the formation of up to 4–7 microbulbs. Cultivation on a medium supplemented with 0.5 mg L⁻¹ IBA (indole-3-butyric acid) resulted in the formation of mature bulbs covered with scales. These results can be successfully used in biodiversity conservation programs for the endemic Tulipa species. In addition, they provide a valuable basis for future biotechnological research, including microclonal propagation, the establishment of gene banks, and the development of reintroduction methods for Kazakh endemic Tulipa species. Full article

Background: This article presents the design development of a new crown-tulip trigger mechanism to initiate progressive failure and reduce initial collapse load in comparison with the existing trigger designs of bevel and tulip in tubular composite structures. Objectives: Through experimental impact testing, comparisons are drawn to the existing designs, such as the 45° bevel and 4T90° tulip trigger mechanism. Methods: This experimental testing design phase demonstrated a significant improvement in the crush force efficiency of crown-tulip trigger mechanisms compared to the previously established Tulip trigger design (4T90°). The experimental results were utilised to develop equivalent numerical models in LS-DYNA. Results: The validated models were employed for further design development, studying the influence of increased bevel angles (30°, 45°, and 60°), tulip angles (90°, 100°, 120°, 140°, and 160°), crown notch depth, crown notch angle, and number of tulip tips/crown notches on the crashworthiness and force response. Conclusions: This culminated in the numerical design development of the 4T160°-40°-2 mm crown-tulip trigger, which achieved 20% higher specific energy absorption, a 22% increase in crush force efficiency, and a 36% higher mean force compared with the 4T90° Tulip-triggered specimen. The outcomes of this research will be implemented in automotive, aerospace, and defence sub-structures. Full article

The monkeypox virus (MPXV) has spread globally, posing a severe challenge to global public health. This study systematically evaluated the aerosol shedding dynamics of the epidemic Clade IIb MPXV strain in infected young rabbits, along with its direct contact and airborne transmission potential among them. We found that young rabbits could be experimentally infected with MPXV, exhibiting distinct pathogenic features and viral shedding patterns. Young rabbits infected with MPXV shed the virus through nasal secretions and exhaled aerosols, peaking at 7 dpi. In total, 89–95.8% of virus-laden respiratory particles had a diameter ≥4.7 μm. Notably, MPXV can be efficiently shed and transferred among young rabbits through direct contact and airborne routes. The nasal secretions and exhaled virus particles from donor rabbits can be contacted or inhaled by recipient rabbits. Large amounts of viral DNA were detected in the nasal wash of rabbits exposed to contact or airborne exposure. Furthermore, virus particles invade the lungs, causing pathological changes and disseminating them to multiple organs. However, no infectious virus was successfully recovered from these recipient rabbits, as their exposed or inhaled MPXV dose might have been below the MPXV’s minimum infectious dose for young rabbits. These findings indicate that although the airborne transmissibility of the current MPXV strain is relatively limited, inhalation of viral particles following airborne exposure can still result in bodily damage. Continuous monitoring of MPXV transmissibility and mutation evolution is imperative to prevent efficient respiratory aerosol transmission, which guides global monkeypox prevention and control strategies. Full article

The increasing demand for natural, safe, and sustainable ingredients is driving innovation in cosmetic science. This study assessed the anti-aging potential of 17 petal extracts using a multidisciplinary bioanalytical approach. In vitro spectrophotometric assays evaluated anti-wrinkle (anti-elastase), anti-pigmentation (anti-tyrosinase), and antioxidant (DPPH, ABTS) activities, while cytotoxicity was tested on HaCaT keratinocytes. Chemical profiling using HPTLC and UHPLC–MS/MS identified 17 phenolic compounds. For the first time, petals from prairie rose (Rosa setigera Michx.), common peony (Paeonia officinalis L.), horse-chestnut cultivars (Aesculus hippocastanum L., Aesculus × carnea Zeyx.), lilac (Syringa vulgaris), mock-orange (Philadelphus pubescens Loisel), orange lily (Lilium bulbiferum L.), garden tulip (Tulipa gesneriana L.), ivy geranium (Pelargonium × peltatum (L.) L’Hér. ex Aiton), and wallflower (Erysimum × cheiri (L.) Crantz) were studied for their skin anti-aging properties. Prairie rose, peony, and ivy geranium extracts showed strong anti-elastase activity; rose and peony also demonstrated high antioxidant potential, while lilac exhibited significant anti-tyrosinase effects. Key phenolic constituents—caffeic acid, p-coumaric acid, and gallic acid—were further examined via molecular docking, which confirmed their inhibitory properties by revealing inhibition mechanisms. All extracts were confirmed to be non-toxic in zebrafish acute toxicity assays at relevant concentrations. This integrative strategy effectively links chemical composition with biological activity, offering valuable insight into the development of safe, plant-derived anti-aging agents for sustainable cosmetic applications. Full article

The evolution of a flame front in a channel was considered in a two-dimensional approximation. In the approximation of the potential flow of combustion products and unburned mixture, the formation of a finger-shaped flame was considered after ignition at the closed end of the channel, on the channel axis, and on the side wall of the channel. The prerequisites for the formation of a tulip-shaped flame were considered in a potential approximation. The method of conformal mapping was used. Simple analytical functions were used that allowed equipotential lines and streamlines to be transformed. The shape of the flame front was obtained. The analytical results were compared with the experimentally obtained results of the flame front evolution and with numerical results obtained by other authors. The conditions for the applicability of the conformal mapping to a reacting gas mixture were given. Full article

The Computational Fluid Dynamics (CFD) method is used to analyze the transient flow patterns and vortex evolution during the startup process of a novel tulip-type hydraulic turbine rotor. The model is validated with experimental results for the rotor’s torque and power coefficients. The results show that the tulip-type rotor exhibits unique flow patterns compared to the traditional rotor. Vortices at different locations around the rotor influence the startup moment, either enhancing or suppressing it. Vortices downstream of the rotor form on the convex side of the blades, creating negative pressure that enhances startup and rotational performance. The expanded top design of the tulip-type rotor substantially improves startup performance through four distinct aspects: smoothly guiding incoming flow, dissipating gap vortices, clearing vortices to prevent blockage, and enhancing fluid-blade interaction to increase energy conversion efficiency. These characteristics of transient flow patterns and vortex evolution reveal the startup mechanism of the tulip-type rotor, providing a foundation for understanding the fluid dynamics of novel rotor designs and supporting the optimization of hydraulic turbine performance. Full article

Fruits are increasingly recognized as an important part of a healthy diet. Fruit crops represent a wide range of woody perennial species grown in orchards. Water availability is a primary environmental factor limiting fruit crop growth and productivity. Erratic rainfall patterns and increased temperatures due to climate change are likely to increase the duration of droughts. This review aims to highlight the different mechanisms by which fruit crops respond to water stress deficits. Emphasis is placed on physiological, genetic and epigenetic determinants of stress response in fruit crops. These findings can contribute to a deeper understanding of the underlying effects of drought. We also describe new research opportunities made possible by the increasing availability of population-level genomic data from the field, including genome-wide association studies (GWAS) and high-throughput phenotyping. Full article

Bulb rot is one of the most destructive diseases of tulip (Tulipa gesneriana L.). In November 2022, rotten tulip bulbs and terminal buds were found in Songjiang District, Shanghai, China. Fungal isolates were isolated from the rotten bulbs and identified as Fusarium based on colony morphology and ITS sequences. Further analyses of tef1, rpb1, and rpb2 barcoding sequences and conidial micromorphology identified the Fusarium isolates as F. annulatum. The pathogenicity of the F. annulatum isolates was verified with Koch’s postulates. This is the first report of F. annulatum causing bulb rot disease of tulip. Full article

Preterm birth (PTB; <37 weeks’ gestation) is a persistent problem in the United States that affects non-Hispanic Black women at much higher rates than White women. Several biomarkers have been associated with PTB, including vitamin D deficiency (VDD) and low levels of vitamin D-binding protein (VDBP). However, no biomarker has been found to predict PTB. To identify a predictive biomarker of PTB, gene expression differences were determined in Black women with PTB and full-term births and between women with high and low levels of plasma vitamin D and high and low VDBP levels. In this pilot study of 19 pregnant women from the Biosocial Impact on Black Births (BIBB) study, we found that 47 genes were upregulated and 16 genes were downregulated in women with PTB as compared with women who had a full-term birth, 361 genes were downregulated and 61 genes were upregulated in women with VDD as compared with those that had vitamin D sufficiency, and 44 genes were upregulated and 295 were downregulated in women with low VDBP. Several genes expressed by neutrophils were downregulated in the PTB, VDD, and low VDBP groups. These findings support the idea that vitamin D and VDBP status may be important clinical markers influencing the gene expression of genes associated with PTB. Full article