Sustainable quaternary binders made from metallurgical wastes of northeast Mexico: strength, hydration products, and durability.

In this research, four industrial wastes were used for up to 80% as supplementary cementitious materials (SCMs) in cement mortar systems: ground granulated blast furnace slag, electric arc furnace slag, basic oxygen furnace slag, and waste limestone powder. Quaternary cementitious blends were prepared and studied for up to 120 days. Workability, compressive strength, durability, microstructures, and sustainability studies were performed and compared with Portland cement references. Results showed that more than 30 MPa in compressive strength can be achieved by > 50% replacement with SCMs; only 9% below the reference. Neither H2SO4 nor MgSO4 attacks resulted in critical damages; nevertheless, curing under NaCl solution showed detrimental behavior. C-S-H with a low Ca/Si ratio was identified in the mortars as the main hydration product, possibly intermixed with stratlingite, C-A-S-H and/or hydrotalcite. Environmental impact for the blended cements was determined as the CO2eq. factor from a simple life cycle assessment. The embodied greenhouse gasses varied in 260.2-541.4 kg CO2eq./ton of binder depending on the formulation. This was 40-70% less than Portland cement (922.6 kg CO2eq./ton). The production of the raw materials dominated the polluting emissions, while freight, grinding, and sieving had little environmental impact.

Oral exposure to benzalkonium chlorides in male and female mice reveals alteration of the gut microbiome and bile acid profile.

Benzalkonium chlorides (BACs) are commonly used disinfectants in a variety of consumer and food-processing settings, and the COVID-19 pandemic has led to increased usage of BACs. The prevalence of BACs raises the concern that BAC exposure could disrupt the gastrointestinal microbiota, thus interfering with the beneficial functions of the microbes. We hypothesize that BAC exposure can alter the gut microbiome diversity and composition, which will disrupt bile acid homeostasis along the gut-liver axis. In this study, male and female mice were exposed orally to d7-C12- and d7-C16-BACs at 120 µg/g/day for one week. UPLC-MS/MS analysis of liver, blood, and fecal samples of BAC-treated mice demonstrated the absorption and metabolism of BACs. Both parent BACs and their metabolites were detected in all exposed samples. Additionally, 16S rRNA sequencing was carried out on the bacterial DNA isolated from the cecum intestinal content. For female mice, and to a lesser extent in males, we found that treatment with either d7-C12- or d7-C16-BAC led to decreased alpha diversity and differential composition of gut bacteria with notably decreased actinobacteria phylum. Lastly, through a targeted bile acid quantitation analysis, we observed decreases in secondary bile acids in BAC-treated mice, which was more pronounced in the female mice. This finding is supported by decreases in bacteria known to metabolize primary bile acids into secondary bile acids, such as the families of Ruminococcaceae and Lachnospiraceae. Together, these data signify the potential impact of BACs on human health through disturbance of the gut microbiome and gut-liver interactions.

Assembly, Persistence, and Disassembly Dynamics of Quaternary Caribbean Frugivore Communities.

AbstractHow communities assemble and restructure is of critical importance to ecological theory, evolutionary theory, and conservation, but long-term perspectives on the patterns and processes of community assembly are rarely integrated into traditional community ecology, and the utility of communities as an ecological concept has been repeatedly questioned in part because of a lack of temporal perspective. Through a synthesis of paleontological and neontological data, I reconstruct Caribbean frugivore communities over the Quaternary (2.58 million years ago to present). Numerous Caribbean frugivore lineages arise during periods coincident with the global origins of plant-frugivore mutualisms. The persistence of many of these lineages into the Quaternary is indicative of long-term community stability, but an analysis of Quaternary extinctions reveals a nonrandom loss of large-bodied mammalian and reptilian frugivores. Anthropogenic impacts, including human niche construction, underlie the recent reorganization of frugivore communities, setting the stage for continued declines and evolutionary responses in plants that have lost mutualistic partners. These impacts also support ongoing and future introductions of invader complexes: introduced plants and frugivores that further exacerbate native biodiversity loss by interacting more strongly with one another than with native plants or frugivores. This work illustrates the importance of paleontological data and perspectives in conceptualizing ecological communities, which are dynamic and important entities.

Mass loading, removal and emission of 27 quaternary ammonium compounds, including metabolites of benzalkonium, in a wastewater treatment plant in New York state, USA.

Benzylalkyldimethylammonium (BACs), dialkyldimethylammonium (DDACs), and alkyltrimethylammonium compounds (ATMACs) are quaternary ammonium compounds (QACs) widely used in industrial and consumer products. Nevertheless, little is known about their fates in wastewater treatment plants (WWTPs). We detected 7 BACs, 6 DDACs, 6 ATMACs, and 8 hydroxy- and carboxyl- metabolites of BACs (BACm) in wastewater collected from a WWTP in New York State. The median concentrations of ∑All (sum concentration of all 27 analytes) in influent and final effluent were 31900 and 545 ng/L, respectively, which corresponded to a removal efficiency of 98 %. C14-BAC, C10-DDAC, C18-DDAC, and C16-ATMAC were the major compounds found in influent (collectively accounting for 62 % of ∑All), suggestive of their prevalent usage in consumer products. BACm were detected for the first time in wastewater (median: 1720 ng/L in influent), and they comprised 8-11 % of ∑All in wastewater, which highlighted the importance of monitoring QAC metabolites in wastewater. The mass loadings of QACs into the WWTP were in the range of 1480-10700 mg/d/1000 inhabitants, whereas the corresponding emission rates were in the range of 119-7720 mg/d/1000 inhabitants. QACs present in final effluents may exert low to moderate risks on aquatic organisms, which warrants more attention.

ß-Glucosidases in specialized metabolism: Towards a new understanding of the gatekeepers of plant chemical arsenal.

Plants produce an exceptional multitude of chemicals to compensate with challenging environments. Despite the structural pluralism of specialized metabolism, often defensive compounds are stored in planta as glycosides and reactive aglycones are conditionally activated by specific ß-glucosidases-a large family of enzymes with pluripotent contribution in homeostasis and a pivotal role in plant chemical defense. Typically, these detonating enzymes are characterized by exceptional substrate specificity and, in several cases, even isoenzymes exhibit differentiated molecular or biochemical characteristics. This article focuses on important intrinsic characteristics of plant ß-glucosidases detonating defensive compounds and highlights recent studies with novel implications in regulatory mechanisms.

Unveiling the genome-wide consequences of range expansion and mating-system transitions in Primula vulgaris.

Genetic diversity is heterogeneously distributed among populations of the same species, due to the joint effects of multiple demographic processes, including range contractions and expansions, and mating-systems shifts. Here, we ask how both processes shape genomic diversity in space and time in the classical Primula vulgaris model. This perennial herb originated in the Caucasus region and was hypothesized to have expanded westward following glacial retreat in the Quaternary. Moreover, this species is a long-standing model for mating-system transitions, exemplified by shifts from heterostyly to homostyly. Leveraging a high-quality reference genome of the closely related Primula veris and whole genome resequencing data from both heterostylous and homostylous individuals from populations encompassing a wide distribution of P. vulgaris, we reconstructed the demographic history of P. vulgaris. Results are compatible with the previously proposed hypothesis of range expansion from the Caucasus region approximately 79,000 years ago and suggests later shifts to homostyly following rather than preceding post-glacial colonization of England. Furthermore, in accordance with population genetic theoretical predictions, both processes are associated with reduced genetic diversity, increased linkage disequilibrium, and reduced efficacy of purifying selection. A novel result concerns the contrasting effects of range expansion vs. shift to homostyly on Transposable Elements (TE), for the former process is associated with changes in TE genomic content, while the latter is not. Jointly, our results elucidate how the interactions among range expansion, transitions to selfing, and Quaternary climatic oscillations shape plant evolution.

Green fabrication of biomass-derived carbon dots and bio-based coatings: Potential of enhancing postharvest quality on Chinese flowering cabbage.

The objective of this study was to develop a bio-nanocomposite coating (CQSC) by combining chitosan quaternary ammonium salt (CQAS) and sericin (SC) with biomass-derived carbon dots (CDs) to extend the shelf life of Chinese flowering cabbage (CFC). The effects of different concentrations of CDs (0.2, 0.4, 0.6, 0.8, and 1.0 mg/mL) on the physicochemical, structural, and functional activity of nanocomposite particles were evaluated. CQAS exhibited strong inhibitory effects against Escherichia coli and Bacillus subtilis. Moreover, the application of CQSC on CFC significantly reduced mass losses, slowed the increase in lignin content, maintained ascorbic acid and chlorophyll levels, inhibited the growth of microorganisms, and preserved the unique texture and aroma of CFC during storage at 10 °C compared with uncoated CFC. The results will contribute to the further development of CDs coatings to improve the postharvest preservation effect of fruits and vegetables.

Well-designed chitosan-based cationic porous polymer: A robust material for effective adsorption of endocrine disrupting chemicals.

There is an immediate need for meticulous design of easily accessible, cost-effective, chemically stable and eco-friendly materials for effectively removal of water contaminant. Herein, targeting typical water contaminants, endocrine disrupting chemicals (EDCs), three cationic hyper-cross-linked porous polymers (ciHCP-1, ciHCP-2, ciHCP-3) with multiple adsorption sites were designed with 2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) as precursor. The ciHCP-3 with large surface area (806 m2 g-1) exhibited high sorption capacity (137-366 mg g-1), and fast adsorption kinetics (5 min) for the EDCs, which is superior to the reported sorbents. The adsorption mechanisms can be attributed to the synergistic effect of physisorption and chemisorption. The high preparation reproducibility, physicochemical stability, and reuse capability of ciHCP highlights its great potential in practical water remediation applications.

Informatic application to characterise and identify small mammal species: Arvicolinae (Cricetidae, Rodentia, Mammalia).

The classification of rodent species can be challenging due to high morphological similarities observed among them. This problem is further increased in palaeontological systematics, where classification is traditionally based on the molar morphology. The subfamily Arvicolinae (Rodentia, Mammalia) is one of these rodent groups, whose classification being important for biostratigraphic and climatic studies of the Quaternary period is challenging. We present an application developed using the MatLab informatic algorithm, designed to classify the Arvicolinae species using Geometric Morphometrics (GMM) analyses of the first lower molar. Moreover, the application includes an option to automatically obtain the linear measurements that are commonly used for the identification of these species. This method shows a high degree of accuracy in the species classification, which is expected to increase as the reference database is further developed. This application can serve as an alternative tool for the classification of specimens with unclear morphologies. It can also be used to reduce the time required to manually obtain the linear indices necessary for their classification.

Paleopteran molecular clock: Time drift and recent acceleration.

Applying BEAST v1.10.4, we constructed a Bayesian Inference tree comprising 322 taxa, primarily representing Paleoptera (Odonata and Ephemeroptera; Pterygota), Zygentoma and Archaeognatha (Apterygota; paraphyly), and Neoptera (Plecoptera; Pterygota), based on a 2685 bp sequence dataset. Our analyses revealed that robust dating required the incorporation of both Quaternary and pre-Quaternary dates. To achieve this, our dating incorporated a 1.55 Ma (Quaternary) geological event (the formation of the Ryukyu Islands) and a set of chronologically well-founded fossil dates, spanning from up to 400 Ma (Devonian) for the stem Archaeognatha, 320 Ma (Carboniferous) for the crown of Paleoptera, 300 Ma (Carboniferous) for the crown Ephemeroptera, and 280 Ma (Permian) for the crown Odonata, down to 1.76 Ma (Quaternary) for Calopteryx japonica, encompassing a total of 22 calibration points (events: 6, fossils: 16; Quaternary: 7, pre-Quaternary: 15). The resulting dated tree aligns with previous research, albeit with some dates being overestimated. This overestimation was mainly due to the lack of Quaternary calibration and the exclusive dependence on pre-Quaternary calibration, though the application of maximum age constraints also played a role. Our minimum age dating demonstrates that the molecular clock did not uniformly progress, rendering rate dating an inapplicable approach. We observed that the base substitution rate is time-dependent, with an exponential increase evident from around 20 Ma (Miocene) to the present time, exceeding an order of magnitude. The extensive radiation and speciation of Insecta and Paleoptera, potentially resulting from the severe climatic changes associated with the Quaternary, including the commencement of glacial and interglacial cycles, may have significantly contributed to this increase in base substitution rates. Additionally, we identified a potential peak in base substitution rates during the Carboniferous period, around 320 million years ago, possibly corresponding to the Late Paleozoic Ice Age.

Adaptive radiation of the Callicarpa genus in the Bonin Islands revealed through double-digest restriction site-associated DNA sequencing analysis.

The Bonin Islands, comprised of the Mukojima, Chichijima, and Hahajima Islands, are known for their isolated and distinctive habitats, hosting a diverse array of endemic flora and fauna. In these islands, adaptive radiation has played a remarkable role in speciation, particularly evident in the Callicarpa genus that is represented by three species: Callicarpa parvifolia and C. glabra exclusive to the Chichijima Islands, and Callicarpa subpubescens, distributed across the entire Bonin Islands. Notably, C. subpubescens exhibits multiple ecotypes, differing in leaf hair density, flowering time, and tree size. In this study, we aimed to investigate species and ecotype diversification patterns, estimate divergence times, and explore cryptic species within Callicarpa in the Bonin Islands using phenotypic and genetic data (double-digest restriction site-associated DNA sequencing). Genetic analysis revealed that C. parvifolia and C. glabra both formed single, distinct genetic groups. Conversely, C. subpubescens consisted of six genetic groups corresponding to different ecotypes and regions, and a hybrid group resulting from the hybridization between two of these genetic groups. Population demography analysis focusing on six Chichijima and Hahajima Islands-based species/ecotypes indicated that all species and ecotypes except one ecotype diverged simultaneously around 73-77 kya. The star-shaped neighbor-net tree also suggests the simultaneous divergence of species and ecotypes. The species and ecotypes that simultaneously diverged adapted to dry environments and understory forests, suggesting that aridification may have contributed to this process of adaptive radiation. Moreover, leaf morphology, flowering time, and genetic analyses suggested the presence of two cryptic species and one hybrid species within C. subpubescens.

Effect of Tetrapropylammonium Chloride Quaternary Ammonium Salt on Characterization, Cytotoxicity, and Antibacterial Properties of PLA/PEG Electrospun Mat.

In this study, poly(lactic acid) (PLA)-tetrapropylammonium chloride (TCL)-poly(ethylene glycol) (PEG) nonwoven networks were produced using PLA, PEG with different concentrations (3, 5, 7, and 9 wt%), and TCL. PEG is included as a plasticizer in PLA polymer, which has high biocompatibility but a brittle structure. The importance of this study is to investigate the effect of TCL salt on the characterization of PLA-PEG nanofibers. For this research, the cytotoxicity test system responsible for the fibroblast cell line (L929) was evaluated with the liquid absorption capacity (LAC) and drying time tests for its use in wound dressings. The addition of TCL salt reduced bead formation in PLA-PEG nanofibers and increased the homogeneity of fiber dispersion. The smoothest and most homogeneous nonwoven networks were obtained as PLA-5TCL-PEG. It was also reported that this nonwoven network exhibited liquid absorption behavior with a maximum increase of 150% compared to the PLA-PEG nonwoven network and had the highest Young's modulus value of 12.97 MPa. In addition to these tests, evaluations were made with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), drying time test, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and mechanical tests. In addition, high cell viability was observed in L292 mouse fibroblast cells at the end of the 24th hour, again with the effect of TCL salt. In addition, antibacterial activity was tested against gram-negative E. coli and gram-positive S. aureus bacteria, and it was observed that there was no antibacterial activity. Since PLA-TCL-PEG nonwoven webs have a maximum cell viability of 133.27%, they are recommended as a potential dermal wound dressing.

Quaternary ammoniums activate human dendritic cells and induce a specific T-cell response in vitro.

BACKGROUND: In many countries, neuro-muscular blocking agents (NMBAs) are the first cause of perioperative anaphylaxis. Epidemiological studies identified pholcodine, a quaternary ammonium-containing opiate as one of the sensitization sources. However, NMBA anaphylaxis exists in countries where pholcodine was unavailable, prompting the hypothesis of other sensitizing molecules, most likely quaternary ammonium compounds (QACs). Indeed, QACs are commonly used as disinfectants, antiseptics, preservatives, and detergents. Occupational exposure to QACs has been reported as a risk factor for NMBA anaphylaxis, but little is known about the sensitization mechanism and the capacity of these molecules to elicit an immune response. We aimed to establish the immunogenicity of QACs representative of the main existing chemical structures. METHODS: We measured the sensitization potential of seven QACs (two polyquaterniums, three alkyl-ammoniums and two aromatic ammoniums) by using two standard dendritic cells (DCs) models (THP-1 cell line and monocyte derived-dendritic cells). The allergenicity of the sensitizing compounds was further tested in heterologous and autologous T-cell-DC co-culture models. RESULTS: Amongst the seven molecules tested, four could modulate activation markers on DCs, and thus can be classified as chemical sensitizers (polyquaterniums-7 and -10, ethylhexadecyldimethylammonium and benzethonium). This activation was accompanied by the secretion of pro-inflammatory and maturation cytokines. Furthermore, activation by polyquaternium-7 could induce T-cell proliferation in heterologous and autologous coculture models, demonstrating that this molecule can induce a specific CD4+ T cell response. CONCLUSIONS: We provide evidence at the cellular level that some QACs can elicit an immune response, which could be in line with the hypothesis of these molecules' role in NMBA sensitization.

Eco-friendly, pH-sensitive curcumin-loaded sodium alginate/hydroxyapatite/quaternary ammonium chitosan microspheres with enhanced antibacterial and antioxidant activities for fruit preservation.

The development of intelligent responsive reactive packaging materials with natural polymers shows excellent potential in food preservation. In this study, eco-friendly, pH-sensitive sodium alginate (SA)/hydroxyapatite (HA)/quaternary ammonium chitosan (HACC) composite microspheres loading curcumin (CUR) with excellent antibacterial and antioxidant activities were successfully synthesized. Scanning electron microscopy (SEM) and nitrogen adsorption/desorption tests indicated that the doping of HA substantially increased the specific surface area and pore volume of the microspheres. The loading experiments showed that the efficiency of the microspheres was significantly increased by 49.47 % and 55.10 %, respectively, when HA and HACC were incorporated into the SA network. The release test results suggested that the release rate of SA/HA/HACC microspheres loading CUR (SA/HA/HACC@CUR) increased as the pH decreased, demonstrating notable pH-responsive release characteristics. DPPH free radical scavenging experiments demonstrated that the SA/HA/HACC@CUR had excellent and long-lasting antioxidant capacity. The antibacterial experiments revealed that the SA/HA/HACC@CUR had excellent antibacterial properties, with inhibition rates of 88.73 % and 92.52 % against E. coli and S. aureus, respectively. Making coatings out of microspheres could effectively slow down the rotting and deterioration of cherry tomatoes during storage, suggesting that microspheres with intelligent responses have a broad application prospect in fruit preservation.

Identification of a novel 10-hydroxyevodiamine prodrug as a potent topoisomerase inhibitor with improved aqueous solubility for treatment of hepatocellular carcinoma.

Natural product evodiamine (Evo) and its synthetic derivatives represent an attractive dual Topo 1/2 inhibitors with broad-spectrum antitumor efficacy. However, the clinical applications of these compounds have been impeded by their poor aqueous solubility. Herein, a series of water-soluble 10-substituted-N(14)-phenylevodiamine derivatives were designed and synthesized. The most potent compound 45 featuring a quaternary ammonium salt fragment achieved robust aqueous solubility and nanomolar potency against a panel of human hepatoma cell lines Huh7, HepG2, SK-Hep-1, SMMC-7721, and SMMC-7721/DOX (doxorubicin-resistant cell). Further studies revealed that 45 could inhibit Topo 1 and Topo 2, induce apoptosis, arrest the cell cycle at the G2/M stage and inhibit the migration and invasion. Compound 45 exhibited potent antitumor activity (TGI = 51.1 %, 10 mg/kg) in the Huh7 xenograft model with acceptable safety profile. In addition, a 21-day long-term dose toxicity study confirmed that the maximum tolerated dose of compound 45 was 20 mg/kg. Overall, this study presented a promising Evo-derived candidate for the treatment of hepatocellular carcinoma.

Microfiltration Membrane Pore Functionalization with Primary and Quaternary Amines for PFAS Remediation: Capture, Regeneration, and Reuse.

The widespread production and use of multi-fluorinated carbon-based substances for a variety of purposes has contributed to the contamination of the global water supply in recent decades. Conventional wastewater treatment can reduce contaminants to acceptable levels, but the concentrated retentate stream is still a burden to the environment. A selective anion-exchange membrane capable of capture and controlled release could further concentrate necessary contaminants, making their eventual degradation or long-term storage easier. To this end, commercial microfiltration membranes were modified using pore functionalization to incorporate an anion-exchange moiety within the membrane matrix. This functionalization was performed with primary and quaternary amine-containing polymer networks ranging from weak to strong basic residues. Membrane loading ranged from 0.22 to 0.85 mmol/g membrane and 0.97 to 3.4 mmol/g membrane for quaternary and primary functionalization, respectively. Modified membranes exhibited a range of water permeances within approximately 45-131 LMH/bar. The removal of PFASs from aqueous streams was analyzed for both "long-chain" and "short-chain" analytes, perfluorooctanoic acid and perfluorobutyric acid, respectively. Synthesized membranes demonstrated as high as 90% rejection of perfluorooctanoic acid and 50-80% rejection of perfluorobutyric acid after 30% permeate recovery. Regenerated membranes maintained the capture performance for three cycles of continuous operation. The efficiency of capture and reuse can be improved through the consideration of charge density, water flux, and influent contaminant concentration. This process is not limited by the substrate and, thus, is able to be implemented on other platforms. This research advances a versatile membrane platform for environmentally relevant applications that seek to help increase the global availability of safe drinking water.

On the abundance and importance of AXXXA sequence motifs in globular proteins and their involvement in CßCß interaction.

The AXXXA and GXXXG motifs are frequently observed in helices, especially in membrane proteins. The motif GXXXG is known to stabilize helix-helix association in membrane proteins via CαHO bonding. AXXXA sequence motif additionally stabilizes the folded state of proteins. We found 27,000 and 18,000 occurrences of AXXXA and GXXXG motifs in a non-redundant set of 6000 obligate homodimeric (OD) complexes. Interestingly, this is less pronounced in transient homodimers (TD) and heterodimers (HetD). On average each obligate homodimer contains four AXXXA motifs, it is 2 and 3.5 for HetD and TD, respectively. Focusing on the binding surface it is seen that 27 % of the ODs contain at least one AXXXA motif at the interface, whereas it is 17 % and 15 % for HetD and TD respectively. AXXXA predominantly stabilizes the OD quaternary structure via the side chain CßCß interactions. This interaction is energetically favorable and is found to be a major driving force for OD quaternary structure stability. Cß-Cß interactions are observed ∼6 times higher than the known CαHO interaction for helix-helix stabilization. Two additional new interactions of CßO and OO are observed at the AXXXA containing interface regions. The occurrence of the motif gets drastically reduced if any of the terminal Ala residues are replaced by Gly. Our findings show the importance of AXXXA in providing stability to the quaternary structure through specific hydrophobic interactions and the specificity of the Ala residue at motif termini. The knowledge gained can be used for designing synthetic proteins of improved stability and for designing peptide-based therapeutics.

Understanding the impact of environmentally relevant alkyl C12-16 dimethylbenzyl ammonium chloride concentrations on zebrafish health.

Alkyldimethylbenzylammonium chlorides (ADBACs), classified as second-generation quaternary ammonium compounds, are extensively employed across various sectors, encompassing veterinary medicine, food production, pharmaceuticals, cosmetics, ophthalmology, and agriculture. Consequently, significant volumes of ADBAC C12-C16 are discharged into the environment, posing a threat to aquatic organisms. Regrettably, comprehensive data regarding the toxicological characteristics of these compounds remain scarce. This research aimed to determine whether or not ADBAC C12-C16, at environmentally relevant concentrations (0.4, 0.8, and 1.6 µg/L), may instigate oxidative stress and alter the expression of apoptosis-related genes in the liver, brain, gut, and gills of Danio rerio adults (5-6 months). The findings revealed that ADBAC C12-C16 elicited an oxidative stress response across all examined organs following 96 h of exposure. Nonetheless, the magnitude of this response varied among organs, with the gills exhibiting the highest degree of susceptibility, followed by the gut, liver, and brain, in descending order. Only the gut and gills of the examined organs displayed a concentration-dependent reduction in the activity of superoxide dismutase (SOD) and catalase (CAT). Akin to the oxidative stress response, all organs exhibited a marked increase in bax, blc2, casp3, and p53 expression levels. However, the gills and gut manifested a distinctive suppression in the expression of nrf1 and nrf2. Our Principal Component Analysis (PCA) confirmed that SOD, CAT, nrf1, and nrf2 were negatively correlated to oxidative damage biomarkers and apoptosis-related genes in the gills and gut; meanwhile, in the remaining organs, all biomarkers were extensively correlated. From the above, it can be concluded that ADBAC C12-C16 in low and environmental concentrations may threaten the health of freshwater fish.

Abiotic foldamer quaternary structures.

Abiotic aromatic foldamer sequences have been previously shown to fold in helix-turn-helix motifs in organic solvents. Using simple computational tools, a new helix-turn-helix motif was designed that bears additional hydrogen bond donor OH groups to promote its aggregation into a genuine, trimeric, abiotic quaternary structure. This sequence was synthesized and its self-assembly in solution was investigated by Nuclear Magnetic Resonance (NMR), Circular Dichroism (CD) and Molecular Dynamics (MD) simulations. The existence of two stable discrete aggregates was evidenced, one assigned to the initially designed trimer, the other to a dimer including multiple water molecules. The two species may be quantitatively interconverted upon changing the water content of the solution or the temperature. These results represent important steps in the design of protein-like abiotic architectures.

Enhanced pH-sensitive anthocyanin film based on chitosan quaternary ammonium salt: A promising colorimetric indicator for visual pork freshness monitoring.

An intelligent pH response indicator film is an easy-to-use device for the real-time monitoring of meat freshness during transport and storage. Therefore, a novel pH-sensitive anthocyanin indicator film composed of polyvinyl alcohol-blueberry anthocyanin (BA)-2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) called PAH-2.0 with 1.2 mg/mL HACC to monitor meat freshness using HACC as the colorimetric enhancer has been developed. BA and HACC were mixed and immobilized in the polyvinyl alcohol matrix by hydrogen bonds, as confirmed via Fourier-transform infrared spectroscopy and X-ray diffraction. The inclusion of HACC improved the color stability and antioxidant and antibacterial properties of the PAH-2.0 film. When applied to pork for freshness monitoring at 4 °C, three freshness stages, including fresh, sub-fresh, and spoiled, could be clearly distinguished based on the color variations of the PAH-2.0 film. The distinct hierarchical color change from purple to blue-violet and finally to grayish-blue was highly correlated with the indicators of pork freshness: pH values, total volatile basic nitrogen, and total viable count. This study provides a simple and promising approach for fabricating meat freshness indicator films with high color recognition accuracy, thereby offering new possibilities for visual meat freshness monitoring.