Search Results (55)

The fabrication of a real-time intelligent indication label for food freshness has emerged as an effective strategy to reduce food waste and improve food safety. In this study, utilizing polyvinyl alcohol (PVA) and arabinoxylan (AX) as the polymer matrices, and incorporating purple cabbage anthocyanins (PCAs) as natural pH-responsive agents, we fabricated a PVA/AX/PCA nanofiber-based intelligent indication label via electrospinning. The results confirmed that the nanofibers exhibited uniform morphology and good structural stability, with the PCA successfully embedded within the nanofibers. The nanofiber membrane exhibits a low water contact angle (54°) and demonstrates a tensile strength of 5.34 ± 0.09 MPa with an elongation at break of 32.43 ± 1.02%, while maintaining a certain degree of flexibility. The nanofiber labels exhibited distinct color changes within a wide pH range (2 to 12), which confirms their pH-responsive characteristics. After being stored at 4 °C and 25 °C for 14 days, the maximum color difference related to storage stability was 1.53 ± 0.02. In practical applications at 25 °C, this intelligent label demonstrated significant color changes when monitoring low-temperature-cooked sausages and fresh shrimp, with total color differences of 41.57 and 53.06, respectively. Degradation experiments showed that the nanofiber labels gradually decomposed, reflecting good biodegradability and environmental-protection characteristics. In conclusion, the green intelligent indication label developed in this study offers a feasible solution for real-time monitoring of food quality. Full article

Drought is a major environmental threat to agriculture. This study examined the role of anthocyanins in plant drought tolerance by comparing two basil varieties differing in leaf anthocyanin content: green basil (Ocimum basilicum L. Italiano Classico) and purple basil (Ocimum basilicum L. Dark Opal). The impact of the PEG-induced drought stress was assessed by monitoring changes in chlorophyll a fluorescence parameters (JIP and PAM), leaf pigment content, anthocyanin and total phenolic levels, oxidative stress markers (malondialdehyde, hydrogen peroxide and membrane integrity), as well as radical-scavenging capacity (DPPH assay). Drought stress led to a modification on both the donor (Wk) and acceptor (Vj) sides of PSII, which influences Q_A reoxidation and amounts of the closed reaction centers (1-qP). These changes inhibited photosystem II photochemistry, the rate of the electron transport (ETR), and the rate of the photosynthesis (R_Fd) and decreased performance indices (PI_ABS, PItotal), as well as the photosystem I photochemistry. The drought-induced changes were associated with an increase in the dissipated energy per reaction center (DI₀/RC). The results show that photosynthetic functions in purple basil were less affected under drought stress compared to green basil. The reason for better tolerance of purple basil is associated with elevated anthocyanin levels, which correlate with enhanced antioxidant capacity, reduced hydrogen peroxide accumulation, lower membrane lipid peroxidation, improved relative water content and membrane stability. In addition, rapid cyclic electron flow around photosystem I and a higher carotenoid to chlorophyll ratio contribute to drought tolerance in purple basil. After re-watering, purple basil recovers its photosynthetic function almost completely, unlike green basil, which shows further suppression. The increase in the anthocyanin content and radical-scavenging capacity, as well as the smaller oxidative damage under drought stress, are the main reasons for the better recovery in purple basil. Overall, the findings highlight that higher anthocyanin accumulation in purple basil confers greater drought tolerance and recovery capacity by stabilizing photosynthetic processes and reducing oxidative stress. Full article

The ATP-binding cassette (ABC) gene family represents one of the most extensive and evolutionarily conserved groups of proteins, characterized by ATP-dependent transporters that mediate the movement of substrates across cellular membranes. Despite their well-documented functions in various biological processes, the specific contributions of ABC transporters in eggplant (Solanum melongena L.) remain unexplored. To address this gap, we conducted a comprehensive genome-wide identification and expression profiling of ABC transporter-encoding genes in eggplant. Our investigation identified 159 SmABC genes encoding ABC transporter that were irregularly dispersed across all 12 chromosomes. The encoded proteins exhibited considerable diversity in size, with amino acid lengths varying from 55 to 2628 residues, molecular weights ranging between 4.04 and 286.42 kDa, and isoelectric points spanning from 4.89 to 11.62. Phylogenetic analysis classified the SmABC transporters into eight distinct subfamilies, with the ABCG subfamily being the most predominant. Subcellular localization predictions revealed that most SmABC proteins were localized to the plasma membrane. Members within the same subfamily exhibited conserved motif arrangements and exon–intron structures, suggesting functional and evolutionary conservation. Promoter analysis identified both shared and unique cis-regulatory elements associated with transcriptional regulation. We identified 9 tandem duplication gene pairs and 20 segmental duplication pairs in the SmABC gene family, with segmental duplication being the major mode of expansion. Non-synonymous to synonymous substitutions (Ka/Ks) analysis revealed that paralogs of SmABC family genes underwent mainly purifying selection during the evolutionary process. Comparative genomic analysis demonstrated collinearity between eggplant, Arabidopsis thaliana, and tomato (Solanum lycopersicum), confirming homology among SmABC, AtABC, and SlABC genes. Tissue-specific expression profiling revealed differential SmABC expression patterns, with three distinct genes, SmABCA16, SmABCA17 and SmABCG15, showing preferential expression in purple-peeled fruits (A1, A3, and A5 accessions), implicating their potential involvement in anthocyanin transport. Functional validation via SmABCA16 silencing led to a significant downregulation of SmABCA16 and reduced purple coloration, indicating its regulatory role in anthocyanin transport in eggplant fruit peel. This comprehensive genomic and functional characterization of ABC transporters in eggplant establishes a critical foundation for understanding their biological roles and supports targeted breeding strategies to enhance fruit quality traits. Full article

Background and Clinical Significance: Kaposi sarcoma (KS) is a rare angio-proliferative mesenchymal tumor that predominantly affects the skin and mucous membranes but may involve lymph nodes and visceral organs. Clinically, it manifests as red-purple-brown papules, nodules, or plaques, either painless or painful, often with disfiguring potential. The diagnosis is traditionally based on clinical and histopathological evaluation, although non-invasive imaging techniques are increasingly used to support diagnosis and treatment monitoring. We report a case of HHV-8-negative Kaposi sarcoma evaluated with multiple non-invasive imaging modalities to highlight their diagnostic utility. Case Presentation: An 83-year-old man presented with multiple painful, violaceous papulo-nodular lesions, some ulcerated, on the lateral aspect of his left foot. Dermoscopy revealed the characteristic rainbow pattern. Dynamic Optical Coherence Tomography (D-OCT) allowed real-time visualization of microvascular abnormalities, identifying large serpentine and branching vessels with clearly delineated capsules. Line-field Optical Coherence Tomography (LC-OCT) showed irregular dermal collagen, vascular lacunae, and the presence of spindle cells and slit-like vessels. Histological analysis confirmed the diagnosis of Kaposi sarcoma, revealing a proliferation of spindle-shaped endothelial cells forming angulated vascular spaces, with red blood cell extravasation and a mixed inflammatory infiltrate. Conclusions: Non-invasive imaging tools, including dermoscopy, D-OCT, and LC-OCT, have emerged as valuable adjuncts in the diagnosis and monitoring of KS. These techniques enable in vivo assessment of vascular architecture and tissue morphology, enhancing clinical decision-making while reducing the need for immediate biopsy. Dermoscopy reveals polychromatic vascular features, such as the rainbow pattern, while D-OCT and LC-OCT provide high-resolution insights into vascular proliferation, tissue heterogeneity, and cellular morphology. Dermoscopy, dynamic OCT, and LC-OCT represent promising non-invasive diagnostic tools for the assessment of Kaposi sarcoma. These technologies provide detailed morphological and vascular information, enabling earlier diagnosis and more personalized management. While histopathology remains the gold standard, non-invasive imaging offers a valuable complementary approach for diagnosis and follow-up, particularly in complex or atypical presentations. Ongoing research and technological refinement are essential to improve accessibility and clinical applicability. Full article

As an important characteristic and horticultural crop in China, sweetpotato can be used as food, industrial raw material, vegetable, and ornamental material. Purple sweetpotato for table use is rich in anthocyanin, which leads to some bitter taste, so it needs further quality improvement. Genetic engineering technology is an effective method to improve crop traits, but there are few reports on genes that can improve sweetpotato sweetness and taste. A xylosidase gene (Ibα-XYL1) was cloned from sweetpotato variety ‘Yanshu 25’ with a fragment size of 2796 bp and encoding 932 amino acid sequences. It has a typical transmembrane domain and three functional domains, which are localized at cell membrane. Reduction in Ibα-XYL1 gene expression had no significant effect on the expansion characteristics and anthocyanin content of sweetpotato storage root (SPSR), but it could up-regulate the expression of sucrose synthesis related genes (SuS, SuPS) and promote the accumulation of soluble sugar in fresh transgenic SPSR. At the same time, it could up-regulate the expression of genes related to starch synthesis modifications (GASS, SBE) and starch decomposition (AMY and BAM), reduce the starch granule size and the starch pasting temperature, promote the conversion of starch to maltose, increase the soluble sugar content, and improve the sweetness and taste of steamed transgenic SPSR. The results are of great significance for quality improvement of sweetpotato. Full article

Bacteria respond to metal pollution through sensors that control the uptake and the detoxification machineries. Specificity in metal recognition is therefore a prerequisite for triggering the appropriate response, particularly when facing a mixture of metals. In response to Cu⁺, the purple bacterium Rubrivivax gelatinosus induces the efflux Cu⁺-ATPase CopA by the Cu⁺ regulator CopR. However, genetic analyses have suggested the presence of additional regulators. Here, we show that CadR, the Cd²⁺ sensor, is involved in Cd²⁺ and Cu⁺ tolerance and demonstrate that CopR and CadR share common target genes. Interestingly, expression of the Cu⁺ detoxification and efflux (CopI/CopA) system was induced by Cd²⁺ and downregulated in the double mutant copRcadR⁻. This double mutant was more sensitive to low Cu⁺ concentration than the single copR⁻ mutant, and accumulation of coproporphyrin III pointed to a significantly decreased expression of CopA. Furthermore, analyses of Cd²⁺ toxicity in the cadR⁻ mutant suggested that although CopR is Cu⁺ selective, CopR is involved in Cd²⁺ response since the addition of Cu⁺ alleviates Cd²⁺ toxicity. Based on our current knowledge of metal transport across the inner membrane, Cd²⁺ and Cu⁺ do not share common efflux routes nor do they share common regulators. Nevertheless, the crosstalk between Cd²⁺ and Cu⁺ tolerance systems is demonstrated in the present study. The modulation of Cu⁺ detoxification by a Cd²⁺ regulator in vivo places emphasis on the relaxed selectivity, under elevated metal concentration, in MerR regulators. Full article

Smart colorimetric packaging has been an important method to protect human health from external hazardous agents. However, the currently available colorimetric detectors use synthetic dye probes, which are costly, toxic, difficult to prepare, and non-biodegradable. Herein, an environmentally friendly cellulose nanocrystal (CNC)-supported polyvinyl alcohol (PVA) nanofibrous membrane was developed for the colorimetric monitoring of food spoilage. Anthocyanidin (ACY) is a naturally occurring spectroscopic probe that was isolated from pomegranate (Punica granatum L.). By encapsulating the anthocyanin probe in electrospun polyvinyl alcohol fibers in the presence of a mordant (M), M/ACY nanoparticles were generated. After exposure to rotten shrimp, an investigation on the colorimetric changes from purple to green for the smart nanofibrous fabric was conducted using the coloration parameters and absorbance spectra. In response to increasing the length of exposure to rotten shrimp, the absorption spectra of the anthocyanin-encapsulated nanofibrous membrane showed a wavelength blueshift from 580 nm to 412 nm. CNC displayed a diameter of 12–17 nm. The nanoparticle diameter of M/ACY was monitored in the range of 8–13 nm, and the nanofiber diameter was shown in the range of 70–135 nm. Slight changes in comfort properties were monitored after encapsulating M/ACY in the nanofibrous fabric. Full article

The application of non-imaging hyperspectral sensors has significantly enhanced the study of leaf optical properties across different plant species. In this study, chlorophyll fluorescence (ChlF) and hyperspectral non-imaging sensors using ultraviolet-visible-near-infrared shortwave infrared (UV-VIS-NIR-SWIR) bands were used to evaluate leaf biophysical parameters. For analyses, principal component analysis (PCA) and partial least squares regression (PLSR) were used to predict eight structural and ultrastructural (biophysical) traits in green and purple Tradescantia leaves. The main results demonstrate that specific hyperspectral vegetation indices (HVIs) markedly improve the precision of partial least squares regression (PLSR) models, enabling reliable and nondestructive evaluations of plant biophysical attributes. PCA revealed unique spectral signatures, with the first principal component accounting for more than 90% of the variation in sensor data. High predictive accuracy was achieved for variables such as the thickness of the adaxial and abaxial hypodermis layers (R² = 0.94) and total leaf thickness, although challenges remain in predicting parameters such as the thickness of the parenchyma and granum layers within the thylakoid membrane. The effectiveness of integrating ChlF and hyperspectral technologies, along with spectroradiometers and fluorescence sensors, in advancing plant physiological research and improving optical spectroscopy for environmental monitoring and assessment. These methods offer a good strategy for promoting sustainability in future agricultural practices across a broad range of plant species, supporting cell biology and material analyses. Full article

Antimicrobial resistance is a critical global health issue, with rising resistance among bacteria and fungi. Marine organisms have emerged as promising, but underexplored, sources of new antimicrobial agents. Among them, marine polychaetes, such as Halla parthenopeia, which possess chemical defenses, could attract significant research interest. This study explores the antimicrobial properties of hallachrome, a unique anthraquinone found in the purple mucus of H. parthenopeia, against Gram-negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 9027), Gram-positive bacteria (Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228), and the most common human fungal pathogen Candida albicans ATCC 10231. Antibacterial susceptibility testing revealed that Gram-negative bacteria were not inhibited by hallachrome at concentrations ≤2 mM. However, Gram-positive bacteria showed significant growth inhibition at 0.12–0.25 mM, while C. albicans was inhibited at 0.06 mM. Time-kill studies demonstrated dose-dependent growth inhibition of susceptible strains by hallachrome, which exerted its effect by altering the membrane permeability of C. albicans, E. faecalis, and S. epidermidis after 6 h and S. aureus after 24 h. Additionally, hallachrome significantly reduced biofilm formation and mature biofilm in S. aureus, E. faecalis, and C. albicans. Additionally, it inhibited hyphal growth in C. albicans. These findings highlight hallachrome’s potential as a novel antimicrobial agent, deserving further exploration for clinical experimentation. Full article

The Mediterranean purple sea urchin Paracentrotus lividus (Lamarck 1816) is a remarkable model system for molecular, evolutionary and cell biology studies, particularly in the field of developmental biology. We sequenced the genome, performed a de novo assembly, and analysed the assembly content. The genome of P. lividus was sequenced using Illumina NextSeq 500 System (Illumina) in a 2 × 150 paired-end format. More than 30,000 open reading frames (ORFs), (more than 8000 are unique), were identified and analysed to provide molecular tools accessible for the scientific community. In particular, several genes involved in complex innate immune responses, oxidative metabolism, signal transduction, and kinome, as well as genes regulating the membrane receptors, were identified in the P. lividus genome. In this way, the employment of the Mediterranean sea urchin for investigations and comparative analyses was empowered, leading to the explanation of cis-regulatory networks and their evolution in a key developmental model occupying an important evolutionary position with respect to vertebrates and humans. Full article

The growing demand for gluten-free products requires the study of alternatives to produce nutritionally and technologically favorable foods. The aim was to evaluate the content and antioxidant capacity of gluten-free bread enriched with whole flour of purple maize (PM) and how starch and bioaccessibility of antioxidant compounds were modified during in vitro digestion. Gluten-free bread was prepared with the addition of 34%, 50%, and 70% PM, and white maize bread served as control. The content of total polyphenols, anthocyanins, and antioxidant capacity through FRAP and TEAC was measured. Specific volume, crumb texture, and starch digestibility were determined in the breads. Simultaneously, in vitro digestion and dialysis by membrane were performed to evaluate the bioaccessible and potentially bioavailable fraction. Bread with 34% PM had a similar specific volume and crumb texture to the control, but higher content of polyphenols (52.91 mg AG/100 g), anthocyanins (23.13 mg c3-GE/100 g), and antioxidant capacity (3.55 and 5.12 µmol tr/g for FRAP and TEAC, respectively). The PM breads had a higher antioxidant content and capacity and higher slowly digestible and resistant starch than the control. These parameters increased as the PM proportion rose. After digestion, anthocyanins were degraded, polyphenols and antioxidant capacity decreased, but they remained potentially bioavailable, although to a lesser extent. Bread with 34% shows acceptable technological parameters, lower starch digestibility, and contribution of bioactive compounds with antioxidant capacity. This indicates that purple maize flour represents a potential ingredient to produce gluten-free bread with an improved nutritional profile. Full article

An effective early diagnosis is important for rheumatoid arthritis (RA) management. This study reveals a novel RA detection method using bacteriorhodopsin as a photoelectric transducer, a light-driven proton pump in purple membranes (PMs). It was devised by covalently conjugating a PM monolayer-coated electrode with a citrullinated-inter-alpha-trypsin inhibitor heavy chain 3 (ITIH3)^542–556 peptide that recognizes the serum RA-associated autoantibodies. The direct serum coating decreased the photocurrents in the biosensor, with the reduction in the photocurrent caused by coating with an RA-patient serum that is significantly larger than that with a healthy-control serum (38.1% vs. 20.2%). The difference in the reduction in the photocurrent between those two serum groups widened after the serum-coated biosensor was further labeled with gold nanoparticle (AuNP)-conjugated anti-IgA (anti-IgA-AuNP) (53.6% vs. 30.6%). Both atomic force microscopic (AFM) and Raman analyses confirmed the sequential peptide, serum, and anti-IgA-AuNP coatings on the PM-coated substrates. The reductions in the photocurrent measured in both the serum and anti-IgA-AuNPs coating steps correlated well with the results using commercial enzyme-linked immunosorbent assay kits (Spearman rho = 0.805 and 0.787, respectively), with both a sensitivity and specificity close to 100% in both steps. It was shown that an RA diagnosis can be performed in either a single- or two-step mode using the developed biosensor. Full article

This work shows the potential of a new way of co-treatment of domestic wastewater (DWW) and a liquid stream coming from the thermal hydrolysis of the organic fraction of municipal solid waste (OFMSW) mediated by a mixed culture of purple phototrophic bacteria (PPB) capable of assimilating carbon and nutrients from the medium. The biological system is an open single-step process operated under microaerophilic conditions at an oxidative reduction potential (ORP) < 0 mV with a photoperiod of 12/24 h and fed during the light stage only so the results can be extrapolated to outdoor open pond operations by monitoring the ORP. The effluent mostly complies with the discharge values of the Spanish legislation in COD and p-values (<125 mg/L; <2 mg/L), respectively, and punctually on values in N (<15 mg/L). Applying an HRT of 3 d and a ratio of 100:7 (COD:N), the presence of PPB in the mixed culture surpassed 50% of 16S rRNA gene copies, removing 78% of COD, 53% of N, and 66% of P. Furthermore, by increasing the HRT to 5 d, removal efficiencies of 83% of COD, 65% of N, and 91% of P were achieved. In addition, the reactors were further operated in a membrane bioreactor, thus separating the HRT from the SRT to increase the specific loading rate. Very satisfactory removal efficiencies were achieved by applying an HRT and SRT of 2.3 and 3 d, respectively: 84% of COD, 49% of N, and 93% of P despite the low presence of PPB due to more oxidative conditions, which step-by-step re-colonized the mixed culture until reaching >20% of 16S rRNA gene copies after 49 d of operation. These results open the door to scaling up the process in open photobioreactors capable of treating urban wastewater and municipal solid waste in a single stage and under microaerophilic conditions by controlling the ORP of the system. Full article

A uniformly oriented purple membrane (PM) monolayer containing photoactive bacteriorhodopsin has recently been applied as a sensitive photoelectric transducer to assay color proteins and microbes quantitatively. This study extends its application to detecting small molecules, using adenosine triphosphate (ATP) as an example. A reverse detection method is used, which employs AuNPs labeling and specific DNA strand displacement. A PM monolayer-coated electrode is first covalently conjugated with an ATP-specific nucleic acid aptamer and then hybridized with another gold nanoparticle-labeled nucleic acid strand with a sequence that is partially complementary to the ATP aptamer, in order to significantly minimize the photocurrent that is generated by the PM. The resulting ATP-sensing chip restores its photocurrent production in the presence of ATP, and the photocurrent recovers more effectively as the ATP concentration increases. Direct and single-step ATP detection is achieved in 15 min, with detection limits of 5 nM and a dynamic range of 5 nM–0.1 mM. The sensing chip exhibits high selectivity against other ATP analogs and is satisfactorily stable in storage. The ATP-sensing chip is used to assay bacterial populations and achieves a detection limit for Bacillus subtilis and Escherichia coli of 10² and 10³ CFU/mL, respectively. The demonstration shows that a variety of small molecules can be simultaneously quantified using PM-based biosensors. Full article

The separation of enantiomers plays a critical role in pharmaceutical development, ensuring therapeutic efficacy, safety, and patent protection. It enables the production of enantiopure drugs and enhances our understanding of the properties of chiral compounds. In this study, a straightforward and effective chiral detection strategy was developed for distinguishing between tryptophan (TRP) enantiomers. The approach involved the preparation of a magnetic molecularly imprinted chitosan (MMIC) for preparation of the sample, which was combined with a nitrocellulose membrane (a paper-based analytical device, PAD) integrated with D-TRP covalently grafted with polymethacrylic acid (PAD-PMA_D-TRP). Discriminating between the TRP enantiomers was achieved using AuNPs as a colorimetric probe. Indeed, the presence of D-TRP rapidly induced the aggregation of AuNPs due to its strong affinity to PAD-PMA_D-TRP, resulting in a noticeable change in the color of the AuNPs from red to purple. On the other hand, L-TRP did not induce any color changes. The chiral analysis could be easily performed with the naked eye and/or a smartphone. The developed method exhibited a detection limit of 3.3 µM, and it was successfully applied to detect TRP in serum samples, demonstrating good recovery rates. The proposed procedure is characterized by its simplicity, cost-effectiveness, rapidity, and ease of operation. Full article