Search Results (77)

Biomimetic lattice structures, inspired by natural architectures such as bone, coral, mollusk shells, and Euplectella aspergillum, have gained increasing attention for their exceptional strength-to-weight ratios, energy absorption, and deformation control. These properties make them ideal for advanced engineering applications in aerospace, biomedical devices, and structural impact protection. This study presents a comprehensive bibliometric analysis of global research on biomimetic lattice structures published between 2020 and 2025, aiming to identify thematic trends, collaboration patterns, and underexplored areas. A curated dataset of 3685 publications was extracted from databases like PubMed, Dimensions, Scopus, IEEE, Google Scholar, and Science Direct and merged together. After the removal of duplication and cleaning, about 2226 full research articles selected for the bibliometric analysis excluding review works, conference papers, book chapters, and notes using Cite space, VOS viewer version 1.6.20, and Bibliometrix R packages (4.5. 64-bit) for mapping co-authorship networks, institutional affiliations, keyword co-occurrence, and citation relationships. A significant increase in the number of publications was found over the past year, reflecting growing interest in this area. The results identify China as the most prolific contributor, with substantial institutional support and active collaboration networks, especially with European research groups. Key research focuses include additive manufacturing, finite element modeling, machine learning-based design optimization, and the performance evaluation of bioinspired geometries. Notably, the integration of artificial intelligence into structural modeling is accelerating a shift toward data-driven design frameworks. However, gaps remain in geometric modeling standardization, fatigue behavior analysis, and the real-world validation of lattice structures under complex loading conditions. This study provides a strategic overview of current research directions and offers guidance for future interdisciplinary exploration. The insights are intended to support researchers and practitioners in advancing next-generation biomimetic materials with superior mechanical performance and application-specific adaptability. Full article

Marine mollusk shells are a promising renewable source of calcium-based materials, offering a sustainable alternative for their synthesis. In this study, five types of marine shells—Chamelea gallina, Mya arenaria, Rapana venosa, Mytilus edulis, and Pecten maximus—were calcined at 900 °C for 2 h. The resulting powders were characterized by XRD, FTIR, SEM, PSD, and zeta potential analyses. XRD confirmed the dominant presence of CaO, with residual calcite and portlandite. FTIR spectra supported these findings, indicating the decomposition of carbonate phases and the formation of Ca–O bonds. SEM imaging revealed species-specific microstructures ranging from lamellar and wrinkled textures to compact aggregates, while particle size distributions varied from 15 to 37 μm. Thermogravimetric analysis revealed a two-step decomposition process for all samples, with significant species-dependent differences in mass loss and conversion efficiency, highlighting the influence of biogenic origin on the thermal stability and CaO yield of the resulting powders. Zeta potential measurements showed low colloidal stability, with the best performance found in Rapana venosa and Pecten maximus calcinated samples. Antibacterial activity was evaluated using a direct contact method against Escherichia coli and Enterococcus faecalis. All samples exhibited complete inactivation of E. coli, regardless of exposure time, while E. faecalis required prolonged contact (3.3 h) for full inhibition. The results highlight the potential of biogenic CaCO₃ and CaO powders as functional, antimicrobial materials suitable for environmental and biomedical applications. This study underscores the viability of marine shell waste valorization within a circular economy framework. Full article

The persistent contamination of aquatic environments by heavy metals, particularly Pb²⁺, Cd²⁺, and Cu^2+, poses a serious global threat due to their toxicity, persistence, and bioaccumulative behavior. In response, low-cost and eco-friendly adsorbents are being explored, among which CaCO₃-based biocomposites derived from mollusk shells have shown exceptional performance. In this study, a hybrid biocomposite composed of poly(vinyl alcohol) (PVA) and oyster shell-derived CaCO₃ was computationally investigated using Density Functional Theory (DFT) to elucidate the electronic and structural basis for its high metal-removal efficiency. Calculations were performed at the B3LYP/6-311++G(d,p), M05-2X/6-311+G(d,p), and M06-2X/6-311++G(d,p) levels using GAUSSIAN 16. Among them, B3LYP was identified as the most balanced in terms of accuracy and computational cost. The hybridization with CaCO₃ reduced the HOMO-LUMO gap by 20% and doubled the dipole moment (7.65 Debye), increasing the composite’s polarity and reactivity. Upon chelation with metal ions, the gap further dropped to as low as 0.029 eV (Cd²⁺), while the dipole moment rose to 17.06 Debye (Pb²⁺), signaling enhanced charge separation and stronger electrostatic interactions. Electrostatic potential maps revealed high nucleophilicity at carbonate oxygens and reinforced electrophilic fields around the hydrated metal centers, correlating with the affinity trend Cu²⁺ > Cd²⁺ > Pb²⁺. Fukui function analysis indicated a redistribution of reactive sites, with carbonate oxygens acting as ambiphilic centers suitable for multidentate coordination. Natural Bond Orbital (NBO) analysis confirmed the presence of highly nucleophilic lone pairs and weakened bonding orbitals, enabling flexible adsorption dynamics. Furthermore, NCI/RDG analysis highlighted attractive noncovalent interactions with Cu²⁺ and Pb²⁺, while FT-IR simulations demonstrated the formation of hydrogen bonding (O–H···O=C) and Ca²⁺···O coordination bridges between phases. Full article

Archaeological mollusk shells, such as those of Littorina obtusata/fabalis, hold valuable information about past human behavior and cultural practices. However, the original coloration of these shells, crucial for understanding their symbolic significance, is often lost due to taphonomic processes. Raman spectroscopy is a powerful technique for non-destructive analysis of archaeological samples, enabling the identification of pigments and mineralogical components. In this study, we present a methodology to predict, using Raman spectroscopy and k-means clustering, the original coloration of archaeological L. obtusata/fabalis shells which have lost their original coloration. Raman spectra were acquired from both modern shells, exhibiting a range of natural colors, and archaeological shell samples from La Chora cave (Cantabria, northern Spain). Spectral data were preprocessed to remove noise and baseline effects, and k-means clustering was applied to group the spectra based on their inherent spectral similarities. By comparing the spectral signatures of the archaeological samples with those of the modern shells within the generated clusters, we inferred the likely original coloration of the archaeological specimens. This approach provides a quantitative framework for predicting archaeological shell colors. Full article

Extreme weather events such as heavy rainfall significantly reduce surface salinity in coastal waters, presenting considerable challenges to the aquaculture of Japanese scallops (Mizuhopecten yessoensis) in shallow cage systems. This study investigated the effects of chronic low-salinity stress on the growth performance, antioxidant capacity, and gene expression profile of M. yessoensis using a 60-day salinity gradient experiment. S33 represents the control treatment with normal seawater salinity (33‰), while S30, S28, and S26 represent experimental groups with progressively lower salinities of 30‰, 28‰, and 26‰, respectively. A decline in salinity was accompanied by an increase in oxygen consumption. The S26 group exhibited a higher ammonia excretion rate (2.73 μg/g·h) than other groups, indicating intensified nitrogen metabolism. Growth was inhibited under low-salinity conditions. The S33 group exhibited greater weight gain (16.7%) and shell growth (8.4%) compared to the S26 group (11.6% and 6%), which also showed a substantially higher mortality rate (46%) compared to the control (13%). At 28‰, antioxidant enzyme activities (T-AOC, SOD, CAT, POD) were elevated, indicating a moderate level of stress. However, at the lowest salinity (26‰), these indicators decreased, reflecting the exhaustion of the antioxidant systems and indicating that the mollusks’ adaptive capacity had been exceeded, leading to a state of stress fatigue. NAD-MDH activity was elevated in the S26 group, reflecting enhanced aerobic metabolism under stress. Transcriptome analysis revealed 564 differentially expressed genes (DEGs) between the S33 and S26 groups. Functional enrichment analysis indicated that these DEGs were mainly associated with immune and stress response pathways, including NF-κB, TNF, apoptosis, and Toll/Imd signaling. These genes are involved in key metabolic processes, such as alanine, aspartate, and glutamate metabolism. Genes such as GADD45, ATF4, TRAF3, and XBP1 were upregulated, contributing to stress repair and antioxidant responses. Conversely, the expressions of CASP3, IKBKA, BIRC2/3, and LBP were downregulated, potentially mitigating apoptosis and inflammatory responses. These findings suggest that M. yessoensis adapts to chronic low-salinity stress through the activation of antioxidant systems, modulation of immune responses, and suppression of excessive apoptosis. This study provides new insights into the molecular mechanisms underlying salinity adaptation in bivalves and offers valuable references for scallop aquaculture and selective breeding programs. Full article

The valorization of mollusk shell waste offers a promising alternative to conventional binders in soil stabilization, contributing to circular economy strategies and improved solid waste management. This study aimed to evaluate the mechanical and microstructural behavior of clayey soil stabilized with Waste Seashell Lime (WSL), a binder produced by calcining crushed snail and mussel shells at different temperatures (700–900 °C) and durations (2–4 h). A recommended calcination condition (800 °C for 2 h) was selected based on thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) results. WSL was incorporated at 3%, 7%, and 11% by dry soil weight and activated using NaOH at molarities ranging from 0.5 to 2.0 mol/L. A total of 122 specimens were prepared and tested for unconfined compressive strength (UCS) after 7 and 28 days. The highest UCS (4605 kPa) was recorded for the mix with 11% WSL and 1.0 mol/L NaOH at 28 days. At lower contents (3% and 7%), WSL-treated soils outperformed those stabilized with Type III Portland cement (Type III PC) under the same curing conditions. SEM-EDS analysis revealed the formation of cementitious phases, such as C–S–H and C–A–S–H, and factorial ANOVA confirmed the statistical significance of the WSL content, curing time, and alkali concentration. These results confirm the research hypothesis and demonstrate that alkali-activated WSL, derived from marine shell waste, can serve as a technically viable binder while supporting circular economy principles and waste reuse practices. Full article

Among the commercial mollusks from the Black Sea, the ark clam Anadara kagoshimensis, the oyster Crassostrea gigas, the mussel Mytilus galloprovincialis, the scallop Flexopecten glaber ponticus, and the gastropod Rapana venosa hold the top positions in terms of cultivation and harvesting volumes. Mollusk shells are attracting attention due to their potential use in various biotechnological applications, including nutraceutical production. In the present study, using inductively coupled plasma mass spectrometry, concentrations of essential trace elements (Cr, Mn, Fe, Co, Cu, Zn, Se, Mo, and I) were measured in shells of the five mollusks sampled from the same biotope. The essential element concentrations in the mollusk shells differed significantly. The highest concentrations of Cr, Mn, and I were found in Anadara shells; Fe and Co in Crassostrea shells; Zn in Mytilus shells; and Cu and Se in Rapana shells. Principal component analyses demonstrated the overall accumulation of all elements as the main cause of the total data variance and the species-specific accumulation of certain elements as the second most important source of the data dispersion. Matrices of element concentration correlations showed considerable dissimilarity, which suggested species specificity in the concerted or competing element accumulation. Powdered shells of Anadara, Crassostrea, and Rapana are most suitable to fulfill the daily human requirements for many essential elements, and the consumption of these powders in amounts of less than a few tens of grams appears to be sufficient for this purpose. Full article

Quaternary carbonate strandplains serve as archives of land–sea interaction, including the impacts of storms and tsunamis. Incipient lithification, especially of compound beach/dune ridges within the action zone of salt spray, presents challenges to geological research, which is often limited to exposures. This study combines aerial image analysis with geophysical datasets to assess the morphostratigraphy and internal structure of the Freedom Beach Strandplain along southern Eleuthera Island, The Bahamas. Color-intensity analysis of field photographs and satellite images revealed general patterns that can be used to distinguish between areas with different grayscale parameters (sand-covered surfaces, lithified ridges, vegetation, etc.). Cross-shore (dip-section) high-resolution (800 MHz) georadar images across ten ridges (A-J) documented the internal architecture of swash-aligned ridge–swale sets. Signatures attributed to storms include truncations in shore-normal radargrams, scour features in alongshore (strike-section) images, and an extensive accumulation of large mollusk shells along one of the oldest ridges (ridge J). Preliminary radiocarbon dating yielded ages of up to 600 years, suggesting intense storms with 50–60-year periodicity as a possible mechanism for ridge formation. Full article

Patella vulgata shells preserve geochemical and structural variations that can provide insights into past environmental conditions. Their composition, primarily calcium carbonate with organic residues from the biomineralization process, is influenced by external factors, such as sea surface temperature. Raman spectroscopy has emerged as a rapid, non-destructive tool for studying biogenic carbonates, enabling the identification of crystalline phases, organic components, and ion distribution. In this study, Raman imaging was applied to six shell sections of P. vulgata live-collected from Langre Beach in Cantabria, Spain. Spectral data were acquired using a Raman probe with a 532 nm excitation laser, providing high-resolution mapping of structural and compositional features. The analysis revealed spatial variations in mineralogy, organic matrix distribution, and ion incorporation in the calcium carbonate lattice, suggesting patterns originating during shell formation. Notably, the results suggest a consistent relationship between the organic and mineral components of the shells, with carotenoid distribution and carbonate ion substitution in the calcium carbonate lattice following similar growth patterns. These findings highlight the potential of Raman spectroscopy for studying biomineralization processes and the environmental records preserved in marine mollusk shells. Full article

Herbert D. Athearn (1923–2011) was an avid student of freshwater mollusks. He named his private shell collection “The Museum of Fluviatile Mollusks”, which was meticulously organized at his residence. This collection was curated to current museum standards with detailed labels, all lots with catalog numbers, and all unionoid valves with catalog numbers written in India ink. Specimens’ collecting dates span between 1850 and 2005, with 23,344 cataloged lots containing over 3000 lots of imperiled and extinct taxa. All data for each of the lots are handwritten in paper catalogs. Many lots contain growth series from the smallest juveniles to the largest specimens seen. He traded extensively with collectors worldwide, obtaining specimens from 84 countries. This collection was donated to the North Carolina Museum of Natural Sciences in 2007. To date, 64 percent of this collection has been databased using a relational database, totaling 589,995 specimens. The collection consists of bivalves, primarily Unionidae, Margaritiferidae, and Sphaeriidae, as well as gastropods. There are 73 families represented, with the greatest abundance found in freshwater Pleuroceridae. The Athearn collection donation included his correspondence, his library, field notes, and USGS topographic maps with marked field localities. Full article

This study presents the first comprehensive data on a vermetid formation along the Apulian coast of the Adriatic Sea, representing one of the northernmost records in the Mediterranean. Surveys along the Brindisi coastline employed visual inspection to map the bioconstruction’s distribution and extension. Detailed data on the bioconstruction inner and the outer edge length, thickness, width, slope and topographic complexity were collected at three selected sites. Moreover, photographic replicates were used to assess shell aperture density and diameters of Dendropoma sp. Associated fauna was studied using two quantitative sampling squares in each transect. The results showed that the vermetid bioconstruction consisted of a thin, encrusted monolayer (thickness < 1.5 cm) that extended for 3.273 linear kilometers, covering 17.23% of the investigated area; it had an average width of 0.5 m, with a mean density of Dendropoma sp. at 2.52 ind/cm². The associated fauna was composed of 47 taxa dominated by crustaceans, mollusks and annelids. Species richness was correlated with the bioconstruction’s thickness and complexity. These findings underline the ecological importance of vermetid bioconstructions as biodiversity hotspots. The lack of massive mortality events along the Apulian coast, in contrast to other Mediterranean vermetid bioconstructions, underscores the necessity for targeted conservation measures. Full article

Background: With the rapid expansion of aquaculture, the impact of rearing environments on the morphological characteristics of marine species has become a critical research focus. This study investigates the morphological differences between wild and cultured populations of B. areolata, a commercially valuable marine mollusk, to understand how aquaculture environments influence morphological traits. Objective: The study aims to evaluate the morphological variance between wild and cultured populations using multivariate statistical techniques and to analyze the ecological implications of these differences. Methods: A total of 120 specimens (56 cultured, 64 wild) were collected from 2 habitats in Hainan, China, and analyzed for 9 morphological traits. Statistical methods, including Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA), were used to assess morphological differences. Results: The study revealed significant morphological differences between wild and cultured populations of B. areolata. Cultured populations exhibited greater morphological uniformity, particularly in traits such as shell height, shell length, and total weight. In contrast, wild populations showed higher variability in traits like shell thickness and shell aperture width, driven by resource heterogeneity and natural selection pressures in their environment. Conclusion: The findings suggest that aquaculture environments significantly influence the development of morphological traits, potentially affecting mollusk adaptability and survival in natural habitats. These results provide valuable insights into aquaculture management and strategies for conserving wild populations. Full article

Modern dentistry is turning towards natural sources to overcome the immunological, toxicological, aesthetic, and durability drawbacks of synthetic materials. Among the first biomaterials used as endosseous dental implants, mollusk shells also display unique features, such as high mechanical strength, superior toughness, hierarchical architecture, and layered, microporous structure. This review focusses on hydroxyapatite—a bioactive, osteoconductive, calcium-based material crucial for bone healing and regeneration. Mollusk-derived hydroxyapatite is widely available, cost-effective, sustainable, and a low-impact biomaterial. Thermal treatment coupled with wet chemical precipitation and hydrothermal synthesis are the most common methods used for its recovery since they provide efficiency, scalability, and the ability to produce highly crystalline and pure resulting materials. Several factors, such as temperature, pH, and sintering parameters, modulate the size, purity, and crystallinity of the final product. Experimental and clinical data support that mollusk shell-derived hydroxyapatite and its carbonated derivatives, especially their nanocrystaline forms, display notable bioactivity, osteoconductivity, and osteoinductivity without causing adverse immune reactions. These biomaterials are therefore highly relevant for specific dental applications, such as bone graft substitutes or dental implant coatings. However, continued research and clinical validation is needed to optimize the synthesis of mollusk shell-derived hydroxyapatite and determine its applicability to regenerative dentistry and beyond. Full article

Bivalve mollusks, comprising animals enclosed in two shell valves, are well-adapted to benthic life in many intertidal zones. Clams have evolved the buried lifestyle, which depends on their unique soft tissue structure and their wedge-shaped muscular foot and long extendible siphons. However, molecular mechanisms of adaptative phenotype evolution remain largely unknown. In the present study, we obtain the high-quality chromosome-level genome of Manila clam R. philippinarum, an economically important marine bivalve in many coastal areas. The genome is constructed by the Hi-C assisted assembly, which yields 19 chromosomes with a total of 1.17 Gb and BUSCO integrity of 92.23%. The de novo assembled genome has a contig N50 length of 307.7 kb and scaffold N50 of 59.5 Mb. Gene family expansion analysis reveals that a total of 24 single-copy gene families have undergone the significant expansion or contraction, including E3 ubiquitin ligase and dynein heavy chain. The significant expansion of transposable elements has been also identified, including long terminal repeats (LTR) and non-LTR retrotransposons. The comparative transcriptomics among different clam tissues reveals that extracellular matrix (ECM) receptors and neuroactive ligand receptors may play the important roles in tissue structural support and neurotransmission during their infaunal life. These findings of gene family expansion and tissue-specific expression may reflect the unique soft tissue structure of clams, suggesting the evolution of lineage-specific morphological novelties. The high-quality genome and transcriptome data of R. philippinarum will not only facilitate the genetic studies on clams but will also provide valuable information on morphological novelties in mollusks. Full article

The present work aims to evaluate the applicability of mollusk (Meretrix lusoria) shells as a biosorbent for toxic metal ions (Cd²⁺ and Pb²⁺) following the batch mode biosorption procedure. Some well-known analytical methods have been used to characterize the biosorbent such as a scanning electron microscope (SEM), an energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction. The mechanism of metal ion biosorption was examined using various analytical techniques. Therefore, an evaluation of operating factors such as contact time, pH, initial concentration of metal ions, biosorbent dose, and temperature was performed. The results obtained in this investigation indicated that the optimum conditions for the biosorption of Cd⁺² and Pb⁺² ions are as follows: pH = 6; contact times of 90 min; and the 20 mg/L of initial [M²⁺]. And a biosorbent dosage of 1.0 g/100 mL for each metal ion solution was also determined. The maximum removal efficiency results were 90.6% for Cd⁺² and 91.5% for Pb⁺² at pH 6.0. The biosorption isotherm was investigated using three forms of linear equilibrium (Freundlich, Langmuir, and Temkin models). Kinetic studies were also conducted to determine the equilibrium time for the biosorption of the studied metals utilizing the pseudo-second-order, pseudo-first-order, and intraparticle diffusion model. The data indicate that the biosorption kinetics of Cd²⁺ and Pb²⁺ follow the pseudo-second-order models. According to the present study, it can be identified that the shell of Meretrix lusoria is a suitable biosorbent for Cd²⁺ and Pb²⁺ ions and can contribute to their removal from environmentally polluted water. Full article