Search Results (513)

In this study, a modified Curie–Weiss model was established for the magnetic susceptibility of high-purity molybdenum and Mo–La alloy powders. The elemental composition was analyzed by GDMS, and combined with the M–T and M–H data measured by SQUID, the temperature-independent contributions of weakly magnetic elements such as La and the paramagnetic contributions of impurity ions such as Fe, Co, and Ni were distinguished. Based on the parameters obtained from the nonlinear least squares fitting, the deviation between the magnetic susceptibility at room temperature calculated by the model and the experimental value was within 5%. The results show that this model can reasonably describe the influence of trace impurities on the magnetic susceptibility of the system and provides an effective method for the magnetic prediction of high-purity metal powders. Full article

The giant squid, despite its abundance as a resource, is underutilized for surimi production due to its distinctive odor and poor gel-forming ability. While soaking (e.g., in sodium citrate) can alleviate the odor, its impact on the gel properties remains unclear. This study employed a comparative approach using pork, a benchmark for high-quality gels, to critically evaluate the gel properties of deodorized giant squid. The rheological, textural, and microstructural properties, as well as the water-holding capacity and water distribution, of squid (after sodium citrate soaking) and pork gels were compared. The results demonstrated that the squid gels exhibited a significantly lower storage modulus and higher tan δ value than pork gels, indicating inferior rheological properties. After cooking, the squid gel exhibited a bent shape and markedly lower hardness (approximately 259.78 g) and chewiness (approximately 226.09 g) compared to the pork gels (approximately 3305.92 g and 2781.27 g, respectively). Microstructurally, the squid gels presented a coarse, porous, and discontinuous network with larger pores, contrasting sharply with the fine, dense, and uniform matrix of the pork gels. Correspondingly, the squid gels had inferior water-holding capacity and a higher proportion of free water. This comparison demonstrates that the gel from sodium citrate-soaked giant squid is weak. More importantly, it provides mechanistic insights by highlighting the specific structural and hydration deficiencies responsible for its poor performance. The findings underscore that targeted strategies to modify the protein network are necessary for the effective utilization of giant squid in surimi production. Full article

In vitro cultured biomass of Rindera graeca, a rare endemic plant, is an efficient renewable source of bioactive naphthoquinones, e.g., rinderol, a potential bioactive inducer of apoptosis in cancer cells. Bioengineering strategies, as biomass immobilization on functionalized biomaterial-based scaffolds, elicitation by chitosan, and in situ extraction of metabolites, are tested for intensifying naphthoquinones production in R. graeca hairy roots. The aim of the study was to investigate the effects of hybrid poly(lactic)–chitosan scaffolds on biomass proliferation and rinderol production in R. graeca hairy roots. Effects of chitosan origin (fungal or squid), molecular mass (350–1800 kDa), and concentration (up to 45%) in the developed hybrid scaffolds have been quantitatively identified, and the results were compared to the reference culture system containing an unmodified PLA-based construct. Applying PLA–chitosan scaffold containing 33% of fungal chitosan resulted in 635 times higher rinderol production (3660 µg g_DW⁻¹) than the application of reference scaffolds. Among the tested parameters, the chitosan concentration in the hybrid scaffolds revealed significant importance in rinderol production. To sum up, the developed hybrid PLA-chitosan scaffold may be recognized as a functional key element supporting the production of naphthoquinones in cultures of R. graeca biomass. Full article

Northern shortfin squid (Illex illecebrosus) and longfin inshore squid (Doryteuthis pealeii) are fished commercially and recreationally off Atlantic Canada, but limited reporting, particularly from recreational fisheries, has left major gaps in our understanding of their ecology and fishery dynamics. Our research used three years of data collected through citizen science initiatives, field visits, and commercial index harvesters to provide much-needed descriptions of squid fisheries and basic ecological characteristics, with a particular focus on Newfoundland and Labrador (NL). We documented active recreational squid fisheries landing both species, including the first confirmed observations of longfin inshore squid in the NL fishery. Distinct regional patterns emerged. North Coast Region fishers tended to use different gear and practices, achieved higher catch-per-unit effort (CPUE), and caught larger squid compared to other NL regions. South Coast Region fishers more frequently caught longfin inshore squid, and although relatively low CPUE was reported, this region tended to have a more active recreational fishery. Our findings reveal previously unrecognized regional variation in squid fisheries and highlight the need for improved understanding of squid ecology and the impacts of the recreational and commercial fisheries on the resource off Atlantic Canada. Full article

Historically, clays have been widely used for the treatment of wounds and to stop hemorrhaging. The aim of this study was to combine four natural clay minerals (kaolinite, glauconite, montmorillonite, and bentonite) with magnetite (Fe₃O₄) nanoparticles to produce Fe₃O₄–clay complexes with enhanced antimicrobial properties and chemopreventive activity against melanoma. The magnetite–clay complexes were synthesized by the chemical co-precipitation method and characterized using XRD, TEM, STEM-EDS, SEM, and SQUID magnetometer. Antimicrobial properties were determined by evaluation of MIC values. The most promising materials were also subjected to direct contact antibacterial test according to the OECD standard for porous materials. Cytotoxicity of the complexes towards melanoma cells and normal human skin fibroblasts was assessed by MTT assay. We performed XRD, which confirmed the formation of Fe₃O₄–clay complex materials. It was also proven that complexes exhibited superparamagnetic properties. Microbiological experiments clearly revealed that modification of natural clays with magnetite significantly boosted their antimicrobial properties. Fe₃O₄–montmorillonite and Fe₃O₄–bentonite showed the strongest antimicrobial activity. Moreover, the mentioned complexes had the ability to reduce the viability of melanoma cells by 35–40%, while exhibiting no cytotoxicity against the normal human fibroblast (BJ) cell line, which is an extremely desirable feature. Thus, it may be concluded that Fe₃O₄–montmorillonite and Fe₃O₄–bentonite complexes hold promise for use in the management of infected wounds and wounds after melanoma excision. Full article

Antarctic krill (Euphausia superba) are an essential source of food for whale, seal, several fish, squid and seabird species in the Southern Ocean. Krill also play a major role in biogeochemical cycling and are the target of a growing commercial fishery. Krill can be detected and quantified with echosounders, particularly in swarms, and monitoring krill abundance and distribution is integral to assessing the status of regional populations and managing fisheries. We used echosounders to investigate the hemispherical distribution and behaviour of krill swarms during the Antarctic Circumnavigation Expedition (ACE), a multidisciplinary exercise that included measurements of atmospheric chemistry. Krill swarms were grouped using hierarchical clustering into four principal types: small swarms (on average 2 m high, 25 m long); large swarms (13 m high and 341 m long); deep swarms, which were also densely packed (average depth of 52 m); and shallower swarms, which had lower densities (average depth of 28 m). We found a weak negative relationship between the concentration of atmospheric methane close to the sea surface and the presence of krill. High densities of krill were found in the Amundsen Sea, an area purported to be of increasing importance for krill as the climate changes. Full article

This study details a biorefinery approach to valorize Dosidicus gigas squid pen waste. The process starts with the enzymatic deproteinization of squid pens, which prove effective with both Alcalase and Novozym, with the latter exhibiting a slightly higher efficiency to yield a material with 73% chitin content. Subsequent alkaline hydrolysis produces highly deacetylated chitosan (>90% degree of deacetylation), followed by controlled depolymerization to obtain polymers with molecular weights ranging from 50 to 251 kDa. Both native and depolymerized chitosan exhibit antimicrobial activity against Escherichia coli and Bacillus cereus, with B. cereus demonstrating greater resistance to chitosan compared to E. coli. The research also explores the bioconversion of deproteinization and deacetylation effluents. Deproteinization effluents prove superior in sustaining microbial growth, supporting comparable growth and lactic acid production for human probiotic strains (Lactobacillus plantarum and Leuconostoc mesenteroides) when substituting commercial peptones. Marine bacteria (Pseudomonas fluorescens and Phaeobacter sp.) show lower productivity. Integrating these processes into a biorefinery framework enables the conversion of 1 kg of dry squid pens into 350 g of chitosan, and facilitates the production of 937–949 g of lactic acid using human lactic acid bacteria cultures in media formulated with squid pen-derived effluents, glucose, yeast extract, and mineral salts. This integrated approach highlights the potential for maximizing resource utilization from squid pen waste, reducing environmental impact and generating high-value bioproducts. Full article

The optically pumped magnetometer, OPM-MEG, has the potential to replace the traditional low-temperature superconducting quantum interference device, SQUID-MEG. Event-related spectral perturbations (ERSPs) can be used to examine the temporal- and frequency-domain characteristics of a signal. In this paper, a finger-tapping movement paradigm based on auditory cues is adopted, and OPM-MEG is used to measure the functional signals of the brain. The event-related spectral perturbation values of the right and left hands of right-handed people were calculated and compared. The results showed that there was a significant difference in the event-related spectral perturbations between the right and left hands of right-handed people. In summary, OPM-MEG has the ability to measure the event-related spectral perturbations of the brain during finger movements and verify the asymmetry of motor skills. Full article

The spread of non-indigenous species (NIS) in the Mediterranean poses complex challenges for coastal fisheries, yet the perceptions and adaptive responses of small-scale fishers remain poorly understood. This study surveyed 70 professional fishers across Greek insular and mainland ports to assess fishers’ local ecological knowledge, awareness, and operational strategies related to eleven established marine NIS. Semi-structured interviews recorded demographic and effort profiles, recognition rates, perceived environmental and economic impacts, catch frequencies, gear damage, injury incidents, and behavioral changes. Fishers in the study area demonstrated high overall awareness (~95%), but variable recognition of less familiar taxa (e.g., bigfin reef squid, squirrelfish). Venomous and gear-damaging species (pufferfish, lionfish, rabbitfish) were predominantly viewed negatively, with significant reported gear losses (EUR 600–1345 yr⁻¹) and avoidance of high-incidence areas (25–30% of respondents). Conversely, commercially valuable NIS received more positive appraisals and are increasingly targeted. Spatial heterogeneity in perceptions and adaptations underscores the need for regionally tailored management that integrates fishers’ knowledge, promotes safe handling and selective exploitation of marketable NIS, and supports adaptive governance to mitigate ecological risks while enhancing socioeconomic resilience. Full article

The occurrence of the bigfin reef squid Sepioteuthis lessoniana, a Lessepsian migrant, is documented for the first time from the coastal waters off Malta, based on the collection of a single specimen reported through citizen science. The presence of this species in the broader Strait of Sicily region is further confirmed by a morphometric assessment and genetic analysis of another individual captured off the Pelagian island of Lampedusa. Molecular identification using mitochondrial COI and 16S rRNA markers corroborates the taxonomic identification exercise as it aligns both specimens with Indo-Pacific clades of S. lessoniana. These records represent the first genetically verified occurrences of the species in both Maltese and Italian waters. The findings extend the known Mediterranean distribution of S. lessoniana, emphasizing the Strait of Sicily as an important monitoring region for Lessepsian migrants and highlighting the combined role of integrative taxonomy and citizen science in tracking non-indigenous species introductions. Full article

The development of edible hydrogels with both high strength and toughness remains a considerable challenge. Herein, we report an innovative and straightforward method to prepare robust kappa-carrageenan/konjac glucomannan (κ-car/KGM) double network hydrogels (DNs) through a single heating-cooling cycle followed by immersion in an Na₂CO₃ solution. This method effectively tuned the crosslinking densities of both the rigid κ-car-k⁺ first network and the ductile KGM second network. The resulting κ-car-k⁺/KGM-1:2 DNs demonstrated outstanding mechanical properties, exhibiting compressive strength approximately 10- and 20-fold greater than that of the corresponding single network (SN) κ-car-k⁺ and KGM hydrogels, respectively, accompanied by remarkable toughness. This enhancement is attributed to a sequential failure mechanism where the rigid κ-car-k⁺ network fractures first to dissipate energy, while the ductile KGM network remains intact to maintain structural integrity. Furthermore, the sensory profile of the κ-car-k⁺/KGM-1:2 DNs was remarkably similar to that of squid across all five evaluated attributes (hardness, elasticity, chewiness, brittleness, and palatability). Similarly, the κ-car-k⁺/KGM-1:1 DNs closely matched the sensory profile of abalone, particularly in elasticity, chewiness, brittleness, and palatability. These findings suggest the prepared edible DNs have great potential to simulate high-chewing seafood, offering a new pathway for designing advanced food materials from natural polysaccharides. Full article

Optical mapping, nanotechnology-based multielectrode arrays and automated patch-clamp allow transmembrane voltage mapping with high spatial resolution, as well as L-type calcium and inward rectifier currents measurements using native mammalian cardiomyocytes. However, these methods are limited to in vitro and ex vivo experiments, while magnetocardiography (MCG) might offer a novel approach for non-invasive preclinical safety assessments of new drugs in intact and even conscious rodents by reconstructing the ventricular action potential waveform (rVAPw) from MCG signals. Objective: This study aims to assess the feasibility of rVAPw reconstruction from MCG signals in Guinea pigs (GPs) and validate the results by comparison with simultaneously recorded epicardial ventricular monophasic action potentials (eVMAP). Methods: Unshielded MCG (uMCG) data of 18 GPs, investigated anaesthetized and awake at ages of 5, 14, and 26 months using a 36-channel DC-SQUID system, were analyzed to calculate rVAPw from MCG’s current arrow map. Results: Successful rVAPw reconstruction from averaged MCG showed good alignment with eVMAP waveforms. However, some rVAPw displayed incomplete or distorted repolarization at sites with lower MCG amplitude. Conclusions: 300-s uMCG averaging allowed rVAPw reconstruction in intact GPs. Occasionally distorted rVAPw suggests the need for dedicated MCG devices development, with higher density of optimized vector sensors, and modelling tailored for small animal hearts. Full article

This study established a biological fermentation process using Saccharomyces cerevisiae and Lactobacillus plantarum to deodorize squid cartilage homogenate. The optimal fermentation conditions for S. cerevisiae were determined as follows: fermentation time 105 min, temperature 34 °C, and inoculum size 0.85%. For L. plantarum, the optimum conditions were 79 min, 34.5 °C, and 4.5% inoculum. Based on electronic nose and HS-SPME-GC-MS analyses, S. cerevisiae outperformed L. plantarum in eliminating key offensive odor compounds, especially sulfur-containing compounds and aldehydes, while promoting the formation of pleasant aroma compounds such as esters and ketones (e.g., carvone and δ-pentenol). Mechanistic insights suggest that the enhanced deodorization efficiency of S. cerevisiae may be attributed to its multi-pathway synergistic metabolism, involving enzymes like dioxygenases and sulfide oxidases that facilitate the conversion of malodorous substances into odorless or pleasantly aromatic compounds. These findings provide a valuable theoretical and practical foundation for the high-value utilization of squid processing by-products and propose a promising bio-deodorization strategy for aquatic products. Full article

This study develops integrated bioeconomic management strategies for the common squid (Todarodes pacificus) fishery in Korea’s coastal waters, addressing both biological conservation and economic sustainability amid severe stock depletion and declining fishery profitability. Drawing on recent catch data and cost structures for six Total allowable Catch (TAC)-managed fishery types, common squid-specific economic indicators were estimated using a stepwise cost allocation method. Based on previous research using the Catch—Maximum Sustainable Yield (CMSY) model with limited Catch Per Unit Effort (CPUE) data, the biomass in 2020 was estimated at approximately 56% of Biomass at Maximum Sustainable Yield (BMSY), indicating an overfished state. Scenario-based simulations identified TAC allocation thresholds at which net profits reach zero, providing a benchmark for adaptive quota redistribution. Results show variation in economic sensitivity and common squid dependency among fishery types: common squid-dependent gears such as offshore jigging and East Sea trawl exhibit high vulnerability, while multi-species fisheries such as purse seine remain resilient. These results provide a basis for developing tailored management strategies for each fishery, thereby enhancing the effectiveness of interventions. Accordingly, policy recommendations include dynamic TAC adjustments, expanded monitoring, introduction of an Individual Transferable Quota system, and coordinated stock assessments with China and Japan. These findings contribute to refining Korea’s TAC system by aligning stock recovery goals with the economic viability of fishing operations. Full article

Manganese oxides have recently gained a lot of interest from scientists due to their unique structural, magnetic and optical properties, which make them favorable for diverse nanotechnological applications. Most applications, however, require stable and well-dispersed nanoparticles of nanometer size. Therefore, in this work, we show a procedure for obtaining separated crystallites of manganese oxide ${\mathrm{Mn}}_3$${\mathrm{O}}_4$ on the surface of spherical silica carriers. The morphology and properties of nanoparticles were analyzed based on transmission electron microscopy observations, Raman spectroscopy, and low-temperature SQUID measurements. The analysis of results revealed the formation of well-dispersed ${\mathrm{Mn}}_3$${\mathrm{O}}_4$ nanoparticles with an average size of approximately 9 nm. The magnetic measurements confirmed the characteristic critical temperature, and a narrow hysteresis loop appeared due to the surface anisotropy of nanoparticles. It was additionally demonstrated that such small nanoparticles possess pronounced nonlinear optical properties, as evidenced by strong signals of second and third harmonic generation. The obtained results fully confirmed the synthesis assumptions and offer promising prospects for the development of a new class of highly optically active manganese-based nanocomposites. Full article