Search Results (5,184)

Among myrmecophilous insects, beetles represent the most specialised and diverse group. Myrmecophily is a complex evolutionary strategy encompassing a wide spectrum of interactions with ants, ranging from occasional to obligate relationships, and from mutualistic associations (e.g., trophobionts) to fully parasitic symbioses (social parasites). One of the most remarkable examples of an obligate ant parasite is Paussus favieri Fairmaire,1851 (Carabidae, Paussinae, Paussini), a West-Mediterranean ant-nest beetle. This species spends most of its life inside the nests of Pheidole pallidula (Nylander, 1849) (Hymenoptera, Formicidae), where it exploits the colony’s most valuable resources (ant larvae, pupae, and tenerals) through a suite of sophisticated chemical and structural adaptations that allow it to evade detection and integrate seamlessly into the host colony. For these reasons, P. favieri has recently emerged as a key model organism for studying host–parasite interactions in eusocial systems. In this study, we investigated possible correlations between the nervous system of P. favieri and its remarkable morphological and behavioural adaptations, shedding light on how an extreme environment such as the ant nest may have shaped the beetle’s brain. Our results, although requiring more in-depth analysis, reveal an exceptional development of the central body and the antennal lobes, which rank among the largest recorded across all insect species studied to date. We also report two previously undescribed morphological asymmetries affecting the optic lobes and mushroom bodies. Together, these findings provide new insights into the neuroanatomy of carabid beetles and, more broadly, into the biology of a unique model of ant parasitism, advancing our understanding of the evolutionary adaptations that characterise the highly specialised Paussinae subfamily, laying down the basis for further analysis. Full article

Powder recyclability in metal additive manufacturing has become a critical requirement for improving sustainability, cost-efficiency, and industrial scalability, particularly in powder bed fusion processes such as Selective Laser Melting (SLM) and Electron Beam Melting (EBM). Despite growing interest in powder reuse, the available literature remains fragmented, often addressing powder degradation, process defects, or mechanical performance as isolated topics. This separation limits understanding of how powder lifecycle evolution affects fatigue-critical reliability, where small variations in powder condition may strongly influence long-term structural integrity. This review aims to establish a unified process–structure–performance perspective linking powder reuse, degradation mechanisms, defect evolution, and mechanical reliability in SLM and EBM. A structured literature analysis was conducted to examine changes in powder morphology, particle size distribution, chemical composition, oxygen uptake, moisture interaction, flowability, and thermal history across reuse cycles. Attention was given to the relationship between powder degradation mechanisms and defect formation during processing. The review shows that static mechanical properties, including tensile strength and hardness, may remain comparatively stable after multiple reuse cycles. In contrast, fatigue performance is markedly more sensitive to powder condition, owing to the accumulation of defects such as oxide inclusions, porosity, lack-of-fusion regions, and irregular melt-pool features. Distinct degradation pathways were identified: SLM is mainly governed by oxidation-related effects, whereas EBM is more strongly influenced by particle coarsening, morphology changes, and thermal exposure. Powder recyclability should be considered not only as a sustainability issue but also as a reliability-driven engineering challenge. The proposed framework supports reuse decisions by integrating powder lifecycle assessment with defect tolerance and fatigue-critical performance requirements. Full article

This study investigates the preparation and characterization of tin micro- and nanoparticles with an emphasis on phase-transformation-induced particle formation and chemical purity. Microparticles were generated through repeated phase transformations between β-Sn (white tin) and α-Sn (gray tin), exploiting the associated volumetric changes to induce fragmentation and particle size reduction. The evolution of particle size distribution was systematically analyzed as a function of transformation cycles. The data were analyzed using the modified Johnson–Mehl–Avrami–Kolmogorov equation, and the saturation particle size corresponds to the grain size of the original tin sheet. The phase transformation was induced homogeneously by α-Sn particles and heterogeneously by InSb, and the results were comparable. The influence of the surrounding atmosphere was studied. The increase in oxygen content during repeated phase transformation was measured. In parallel, tin nanoparticles were synthesized via a solution-based route using ammonium hexachlorostannate as a precursor. The nanoparticles precipitated from this solution at mild temperatures during the β-Sn to α-Sn transformation at 13.2 °C. Both micro- and nanoparticles were characterized in terms of morphology and size distribution. The results provide insight into the relationship between phase transformation and particle size reduction mechanisms, and offer a controllable pathway for the preparation of tin particles across micro- and nanoscale regimes. Full article

Visceral organ mass is a major determinant of maintenance energy requirements in cattle, suggesting that equations to predict visceral organ mass could increase the accuracy of estimates of energy requirements. The objective of this meta-analysis was to quantify the relationships of visceral organ mass with the chemical composition of the diet, as well as animal and management characteristics. A database of 170 treatment means from 38 studies was assembled from published literature. Mixed-effects models with animal, management, and diet characteristics as fixed effects and study as a random effect were selected based on the lowest corrected Akaike information criterion (AICc) and evaluated via leave-one-trial-out cross-validation. Out of 16 organs, 15 had concordance correlation coefficient (CCC) values over 0.900, and cross-validated coefficient of determination (R²) values ranged from 0.728 to 0.967 across organs. Dry-matter intake, days on feed, and fiber-related diet characteristics (roughage level, neutral detergent fiber, and physically effective neutral detergent fiber) were the most consistently retained predictors, with crude protein and metabolizable energy concentrations being retained less frequently. These equations provide a quantitative basis for more accurate estimation of visceral organ mass in cattle. Full article

The relationship between the morphology of pygidial glands and the chemical nature of their secretions in the tribe Chlaeniini (family Carabidae) has long been recognised. We analysed the morphological features of the pygidial glands and the chemical composition of their secretions in three taxa: Chlaenius (Chlaeniellus) tristis (Schaller, 1783), C. (Chlaenites) spoliatus spoliatus (Rossi, 1792), and C. (Chlaenius) festivus festivus (Panzer, 1796). We examined the morphology of the pygidial glands in all three taxa using bright-field microscopy (BFM) and nonlinear microscopy (NLM). We used gas chromatography–mass spectrometry (GC–MS) and nuclear magnetic resonance (NMR) to analyse the chemical composition of the secretions. We measured and photographed the glands and conducted comparative morphological analyses. We detected a total of 21 chemicals in the pygidial gland secretions of the studied Chlaeniini. We found the highest number of compounds in C. tristis (17), slightly fewer in C. festivus festivus (13), and the lowest number in C. spoliatus spoliatus (seven). Thirteen compounds were new to the tribe Chlaeniini, eight of which were also new to the entire family Carabidae. The most dominant compound in the secretions of all three taxa was 3-methylphenol. We also discussed the taxonomic value of the chemical composition of the pygidial gland secretions. Full article

The interaction between salt solutions and expansive soils is critical for engineering in chemically aggressive environments. However, the effect of iodide salts on pore water distribution in expansive soils remains poorly understood. This study investigated the transverse relaxation time (T₂) characteristics of pore water in expansive soils under varying KI concentrations (0–20%), moisture content (8.7–26.0%), and dry density (1.26–1.79 g/cm³) using nuclear magnetic resonance (NMR). All T₂ curves exhibited a single peak. Increasing moisture content from 8.7% to 26.0% resulted in increases of approximately 63% in T₂ at peak and 408–439% in peak area. Increasing KI concentration decreased both T₂ at peak by up to 33.3% and peak area by up to 44.0% within the tested range, attributed to diffuse double-layer compression and signal loss. Increasing moisture content broadened the T₂ distribution and linearly increased T₂ at peak and peak area, indicating water gradually occupied larger pore spaces as moisture content rose. T₂ at peak was independent of dry density, while the peak area showed a linear relationship with dry density, consistent with mass balance. The observed systematic linear relationships among T₂ at peak, peak area, and the three experimental variables suggest that NMR is a promising tool for the quantitative assessment of salt solution effects on pore water in expansive soils. These findings provide a theoretical basis for evaluating salt-affected expansive soils in coastal and arid regions. Full article

Plants have developed several dormancy mechanisms essential for resilience in adverse environments. Understanding these mechanisms allows for the development of weed control strategies and enhances seedling production. This study aimed to investigate the anatomical and ecophysiological mechanisms associated with seed coat impermeability and physical dormancy in Mimosa camporum Benth. and other Amazonian Mimosa L. species, emphasizing their effects on water uptake, germination behavior, and ecological adaptation. For M. camporum, the imbibition curve, seed coat anatomy through scanning electron microscopy, and germination tests of seeds subjected to chemical scarification (H₂SO₄) were determined. Data from 25 Amazonian Mimosa species were compiled for ecological and physiological characterization, with subsequent Multiple Correspondence Analysis. Immersion in H₂SO₄ for 5 min is adequate to break dormancy in Mimosa camporum Benth. seeds. In Mimosa camporum Benth., sulfuric acid scarification effectively promoted water uptake and germination, demonstrating the close relationship between seed anatomy, imbibition behavior, and dormancy regulation. Physical dormancy in Amazonian Mimosa L. species is directly associated with seed coat impermeability, especially the presence of macrosclereids in the palisade layer. In the Amazon, the reproductive success and resilience of Mimosa L. species are related to the physical dormancy and desiccation tolerance of their seeds. Full article

In recent years, the applications of melatonin (MT) and hydrogen sulfide (H₂S) have both been proven to improve the post-harvest preservation of horticultural products. However, the specific regulatory mechanism between them in cut flower preservation remains unclear. Here, we conducted research on the combined effect of MT and H₂S during the senescence of cut roses ‘Corolla’, as well as the relationship between endogenous H₂S production and MT. We found that the cut roses treated with MT + H₂S exhibited the longest vase life, the largest flower diameter, and the highest increase of fresh weight compared with those under MT or H₂S treatment alone. We have found that both MT and H₂S can inhibit the contents of the ethylene precursor ACC and the key enzymes ACS and ACO involved in ethylene synthesis in cut roses. Further investigation revealed that the application of hypotaurine (HT), a specific chemical scavenger of hydrogen sulfide (H₂S), compromised the preservation of cut roses. In the combined treatment with HT and melatonin (MT), elevated levels of reactive oxygen species (ROS), along with reduced antioxidant enzyme activities and downregulated expression of associated genes, were observed. However, the combined treatment still demonstrated a superior preservative effect relative to the HT treatment alone. Conversely, MT treatment individually enhanced endogenous H₂S production and upregulated the transcript levels of the H₂S biosynthesis genes RhLCD and RhDCD in petal tissues. These results substantiate that MT extends the postharvest longevity of cut roses by stimulating H₂S synthesis, thus counteracting oxidative damage. Full article

Silicon is among the most abundant elements on Earth, yet its incorporation into organic molecules is atypical in most biological contexts. However, the strategic introduction of silicon, in line with the demonstrated success of the incorporation of other bio-orthogonal elements, has emerged as a powerful approach in medicinal chemistry, enabling access to small molecules with unique chemical, physical, and biological properties that offer improved potency, stability, tolerability, or bioavailability profiles for the discovery and development of anticancer therapeutics. In this review, we describe the direct connection between reactivity and physiochemical paradigms of different classes of organosilicon-containing functional groups and their strategic deployment in small molecule design, including silanes, silyl ethers, siloxanes, and organosilicates. Specifically, we aimed to demonstrate how these strategies can be informed by first principles of reactivity in organosilicon containing functional groups, in both synthetic small molecules and bioactive natural products. Particular emphasis is placed on how silicon replacement and addition can be leveraged beyond simple isosteric carbon replacement, and how consequent structure–activity relationships arising from installation of diverse organosilicon motifs can also serve a unique role in unveiling new aspects of biological mechanism and function. Ultimately, the growing body of literature in applications of organosilicon-containing anticancer small molecules and the increasing sophistication and selectivity of synthetic methods used to construct these motifs will undoubtedly continue to expand the appreciation of organosilicon-based functional groups in the medicinal chemist’s toolbox. Full article

Calibration-free electrochemical sensing is increasingly promoted as a route to simpler, more deployable analytical devices. However, the term is used inconsistently, ranging from genuinely absolute measurement to factory-calibrated, ratiometric, self-referenced, drift-corrected or model-assisted operation. This review critically examines what calibration-free sensing can and cannot mean in electrochemical analysis. We argue that a strict claim requires that the reported measurand be obtained from an internally constrained physical, chemical or stoichiometric relationship, with the required parameters known, controlled or independently measured within an uncertainty framework. Potentiometric, amperometric, coulometric, impedimetric, biosensing and affinity-based approaches are compared to show where empirical calibration is removed and where it is shifted to fabrication, internal correction, model fitting, matrix correction or context-specific validation. Particular attention is given to coulometric and thin-layer systems, geometry-constrained devices, electrochemical aptamer-based sensors and self-diagnostic platforms. We propose a classification scheme, a decision tree and a minimum assumption map linking measurand definition, electrochemical signals, signal-to-result relationships, parameter sources, uncertainty, matrix transfer, reproducibility and independent-method agreement. The review provides a practical framework for distinguishing genuinely calibration-free measurements from calibration-reducing, conditionally calibration-free and drift-corrected strategies. Full article

Ethylene biosynthetic enzymes, 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS) and ACC oxidase (ACO), participate in the floral sex differentiation of bitter gourd (Momordica charantia). However, the relationship between their structural features and developmental expression patterns remains to be further clarified. In this study, eight McACS and five McACO genes were identified using the Dali-11 reference genome. AlphaFold 3-based modeling showed structural differences between the two families, particularly regarding the diverse C-terminal flexibilities of McACS proteins. Targeted qRT-PCR profiling during the critical 1.0–3.0 mm early floral bud stage revealed that McACS7, a structurally stable Type III member, along with McACS1, McACS12, and McACO2, were significantly upregulated during natural female flower development. Furthermore, treatment with silver nitrate (AgNO₃), an ethylene perception inhibitor, suppressed the transcription of these synthesis genes to basal levels and induced hermaphroditic flower formation. Instead of fully elucidating the downstream molecular mechanisms, these findings provide robust candidate-gene evidence and transcriptional profiling that link the ethylene biosynthetic machinery to the chemically induced sex reversal process, thereby laying a solid foundation for future functional characterization. Full article

In response to the increasing needs for environmentally friendly products, lignocellulosic natural fibers have been of interest as potential replacements for synthetic reinforcement materials in textiles, composites, and related applications. Among these resources, bast fibers derived from plant stems (flax, hemp, nettle, jute, hop), which contain a high cellulose content, have good mechanical properties, low density, and are renewable, are highly promising. Steam explosion has emerged as a green fiber extraction, defibrillation, and surface modification pretreatment technology. Despite the growing number of studies on steam-exploded natural fibers, a comprehensive understanding of the relationships between processing conditions, fiber modifications, mechanisms, and end-use performance remains limited. This review investigates the structural, chemical, and morphological influences of steam explosion on bast fibers. Specifically, it focuses on the mechanism of steam explosion including the solubilization of hemicellulose, partial lignin redistribution or removal, fiber individualization, and cellulose enrichment. The literature indicates that steam explosion can improve fiber separation, fineness, surface morphology, and interfacial adhesion of the composite materials and reduce the use of hazardous chemicals compared with conventional extraction methods. Nonetheless, conflicting results have also been documented, where the same steam explosion conditions can yield distinct fiber characteristics according to biomass type, composition of biomass, moisture concentration, and the amount of processing involved. Excessive treatment severity may lead to fiber shortening, cellulose degradation, and deterioration of fiber quality, particularly for textile applications requiring long fibers. This review highlights current knowledge gaps regarding the optimization of processing conditions, the understanding of steam explosion mechanisms, and the scale-up of the technology for industrial applications. Full article

To eliminate the complex nonlinear mixing relationships among spectral features in near-infrared (NIR) quantitative analysis, and to overcome the limitations of principal component analysis (PCA), which relies solely on covariance structure and linear assumptions and is therefore incapable of effectively handling nonlinear signals, this study employs kernel-independent component analysis (KICA), for nonlinear feature extraction from NIR spectra, combined with a regression model to achieve rapid detection of tannin content in sorghum grains. KICA effectively separates nonlinearly mixed source signals by mapping spectral data into a high-dimensional feature space via the kernel trick. The prediction model built on KICA-extracted features and support vector regression (SVR) consistently delivered the highest test-set prediction accuracy and exhibited the smallest training-to-test R² gap among all evaluated models across repeated random splits, confirming its superiority over PCA-based feature extraction methods and standalone SVR, and its competitive performance relative to ICA-based methods, in both predictive accuracy and generalization capability. Additionally, KICA yielded a lower reconstruction error for the original spectra, indicating its ability to more completely retain the nonlinear informative content of the spectral data. By calculating the mean absolute coefficient of each independent component, it was found that the component with the highest contribution was strongly correlated with the wavelength range near the characteristic absorption peaks of tannin, thereby enhancing the chemical interpretability of the features. On a publicly available corn NIR dataset, the proposed method also achieved superior prediction results compared with benchmark methods, validating its generalization capability across different sample types and quality attributes. This study confirms the feasibility of introducing nonlinear blind source separation via KICA into NIR quantitative analysis, offering a promising approach for spectral feature extraction in the rapid quality assessment of agricultural products with complex matrices. Full article

Developing biodegradable and functional polymeric materials for active food packaging is essential to mitigate the environmental burden of petroleum-based plastics. In this context, gelatin/chitosan (G–Ch) nanofibrous mats were fabricated via solution blow spinning (SBS) and functionalized with snail slime (SS) and Pinus sylvestris essential oil (PSEO) to enhance their bioactivity and barrier performance. SS is rich in glycoproteins and natural bioactive compounds, while PSEO is characterized by terpene-based antimicrobial and antioxidant activities. SS and PSEO were incorporated into the G–Ch polymeric matrix to enhance the bioactivity, structural functionality and preservation performance of the nanofibrous mats. Three formulations (G–Ch, G–Ch–SS, and G–Ch–SS–10PSEO) were designed to elucidate the influence of snail slime and essential oil incorporation on the structure–property–function relationships of the nanofibrous mats. Morphological analysis revealed a smooth and bead-free fibrous structure across all formulations. The average fiber diameter (AFD) increased from 191.83 nm for G–Ch to 263.88 nm for G–Ch–SS and 295.83 nm for G–Ch–SS–10PSEO. FTIR and XRD analyses showed the physical encapsulation of the active compounds without significant chemical interactions. Furthermore, the incorporation of PSEO increased surface hydrophobicity and reduced air permeability, indicating the formation of a more compact fibrous structure with enhanced barrier properties. The functional performance of the nanofibrous mats was significantly improved by the addition of snail slime and PSEO. The G–Ch–SS–10PSEO formulation exhibited the highest antioxidant activity, reaching 36.8% for DPPH and 42.7% for ABTS, along with enhanced antibacterial efficacy against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Application tests on chicken wings demonstrated that the bioactive nanofibers effectively suppressed microbial growth, limited pH increases, and reduced lipid oxidation during 14 days of refrigerated storage. Overall, the results demonstrate that the synergistic integration of snail slime and essential oil within a biodegradable polymer matrix provides a promising strategy for designing active nanofibrous materials with enhanced structural and bioactive properties for sustainable food-packaging applications. Full article

Silages produced from different forage species exhibit substantial variability in chemical composition, digestibility, and fermentation characteristics, which may influence forage quality and preservation efficiency in livestock systems. This study evaluated the nutritional and fermentative variability of silages produced from six forage species (Zea mays L., Sorghum bicolor L., Medicago sativa L., Helianthus annuus L., Cenchrus purpureus, and Saccharum officinarum L.) using multivariate analytical approaches. A database comprising 237 observations, obtained from 24 independent ensiling experiments, was analyzed. Chemical composition, fermentative parameters, and in vitro dry matter digestibility were evaluated through principal component analysis (PCA), canonical discriminant analysis (CDA), and Pearson correlation analysis. Significant differences among forage species were detected (p < 0.05). PCA explained 76.2% of the total variance in the chemical dataset and 85.1% in the fermentative dataset, revealing clear multivariate patterns among silage types. Chemical composition traits provided greater discrimination among silages than fermentative variables, particularly through differences in fiber fractions, soluble carbohydrates, digestibility, and buffering capacity. Corn and sorghum silages were associated with greater starch availability and favorable fermentation profiles, whereas elephant grass and sugarcane exhibited higher fiber concentrations. Alfalfa showed greater crude protein concentration and digestibility, while sunflower was characterized by elevated lignin concentration. Overall, multivariate analyses provided an integrated interpretation of nutritional and fermentative relationships among silages, highlighting species-specific responses to ensiling and their implications for forage conservation and livestock production systems. Full article