Search Results (813)

PVP-stabilized silver nanoparticles (Ag NPs) were functionalized with sildenafil (Sil), leading to spherical NPs (Ag@Sil NPs) with a size of about 30 nm as observed through transmission electron microscopy and dynamic light scattering. Fourier-transformed IR spectroscopy confirmed the covering of the particles with Sil. The Ag@Sil NPs were incorporated into a 0.1 wt% ointment and tested for the treatment of acute anal fissures in a preliminary medical study involving 50 patients. Typical symptoms such as pain, bleeding, itching, and mass sensation were improved in the intervention group with no adverse effects. Molecular docking showed strong interactions with docking scores slightly above −10 kcal/mol between sildenafil and two different model complexes [Ag–Sil]⁺ for the Ag-bound sildenafil with either piperazine-N- or pyrazole-N-bound Ag⁺ ions and the muscarinic M2 and the nicotinic acetylcholine α3β4 receptor, which are both involved in anal sphincter regulation. All three showed superior binding compared with nitroglycerin and L-arginine. The residue analysis revealed a higher number of relevant interactions for the sildenafil and the two Ag⁺ complexes, compared to nitroglycerin and L-arginine, fully in line with the differences in the docking scores. Full article

In contemporary society, breast health has become a significant public health concern, particularly among women. According to statistics from the World Health Organization, both the incidence and mortality rates of breast tumors have steadily increased in recent years. Therefore, effective early-stage screening and postoperative monitoring are essential for maintaining breast health. However, conventional clinical diagnostic modalities are typically bulky, operationally complex, and unsuitable for continuous real-time monitoring, which limits their use in portable and everyday health management applications. To address these limitations, this study proposes a machine learning-integrated wearable piezoelectric sensing platform as an auxiliary tool for breast health assessment. The device consists of a PDMS matching layer embedded with flexible silver nanowires, a P(VDF-TrFE) piezoelectric layer, and a multi-channel low-noise signal acquisition circuit. It is capable of acquiring acoustic echo signals from tissue-mimicking environments and automatically evaluating signal validity using a convolutional neural network (CNN). By integrating piezoelectric sensing with deep learning-based signal analysis, the proposed system achieves a signal-to-noise ratio exceeding 70 dB and a real-time classification accuracy above 96% under controlled conditions. These results demonstrate that the platform provides a compact, portable, and intelligent approach for wearable sensing of mechanical heterogeneity and highlight its potential for future development in continuous biomedical monitoring technologies. Full article

The South American silver croaker, Plagioscion squamosissimus, holds significant importance for the artisanal fisheries operating in the sub-middle and lower courses of the São Francisco River, located in northeastern Brazil. Its complex horizontal movement patterns and habitat-use preferences are not fully understood in the waters of hydroelectric dam reservoirs, raising important questions for the rational and sustainable management of this species. This study aimed to identify the habitat use of P. squamosissimus individuals captured in three fishers’ associations (Olho D’água do Casado, Petrolândia and Rodelas). Individuals were collected between September 2023 and March 2024. A selection of 25 individuals per location from the same age group (+2 years) was used, following annual age estimation based on existing growth curves. Element-to-calcium (element/Ca) ratios in the otolith cores and edges were determined using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The data were analyzed using univariate and multivariate statistics to assess the degree of separation between individuals in relation to natal origin (otolith cores) and time of capture (otolith edges) from the three sampling sites. Significant differences in element/Ca ratios between core and edges of the otolith were observed for Ba/Ca, Mg/Ca, Mn/Ca and Sr/Ca ratios. These results indicate an ontogenetic change in the habitat use, in which similarity in core signatures suggests a common natal origin, likely influenced by shared environmental conditions of the individuals investigated in this study. Full article

Particulate emerging contaminants (PECs) pose increasing ecological risks due to their widespread occurrence and complex environmental behaviors, yet their heterogeneous toxic mechanisms remain poorly understood, especially under environmentally relevant conditions and concentration gradients. Here, Chlorella vulgaris was used as a model organism to systematically compare the effects of polystyrene nanoparticles (PSNPs), silver nanoparticles (AgNPs), and titanium dioxide nanoparticles (TiO₂NPs) across environmentally relevant and elevated concentrations (100 μg/L and 10 mg/L). Distinct toxicity pathways were identified among PEC types. PSNPs primarily induced chronic interference via particle–cell interactions, heteroaggregation, sedimentation-driven shading, and extracellular polymeric substance (EPS) regulation, rather than ROS-dominated toxicity. In contrast, AgNPs exhibited transformation-driven toxicity, undergoing intracellular speciation into Ag₂S, AgCl, and Ag⁺, which triggered oxidative stress, membrane damage, and lipid peroxidation. TiO₂NPs showed relatively high bioavailability and persistent oxidative stress effects. These results demonstrate that PEC toxicity evolves with particle type and concentration. Importantly, oxidative stress alone is insufficient to capture PEC ecotoxicity, which also involves the long-term impacts on algal behavior, sedimentation dynamics, and energy metabolism. This study provides mechanistic insights into PEC-induced algal toxicity and supports the source-oriented management of particulate pollutants in aquatic environments, particularly in hotspot scenarios such as wastewater discharge and sediment resuspension. Full article

Circaea lutetiana (Onagraceae) is a perennial medicinal species widely distributed across temperate forest ecosystems of Europe, Asia, and North America. This mini-review integrates current knowledge on the botanical characteristics, ecological distribution, phytochemical composition, and biological properties of Circaea lutetiana, with particular emphasis on its dominant polyphenolic constituents. Available studies demonstrate that the species is rich in flavonoids, phenolic acids, ellagic acid derivatives, and ellagitannins, among which oenothein B represents a characteristic and major constituent. Beyond polyphenols, structurally characterized glycosides, lipophilic metabolites, phytosterols, triterpenoids, fatty acids, tocopherols, and mineral elements contribute to the chemical complexity of the species. The reported biological activities of Circaea lutetiana, including antioxidant, anti-inflammatory, antihypertensive, and antimicrobial effects, are discussed in relation to the phytochemical profile of the plant and the biological significance of its major constituents. Recent research in green nanotechnology has additionally highlighted the potential of Circaea lutetiana extracts, particularly in the biosynthesis of silver nanoparticles, where plant metabolites act as reducing and stabilizing agents and may contribute to improved antimicrobial performance. Full article

Plant polysaccharides, such as Astragalus polysaccharide (APS) and Glycyrrhiza polysaccharide (GPS), have potential as functional feed additives. This study investigated the effects of dietary APS and GPS on growth-related traits, serum biochemical and immune indices, antioxidant capacity, intestinal health, and microbial diversity in early-weaned squabs. A total of 192 15-day-old Silver King squabs were randomly divided into four groups: the control group (CK), the 800 mg/kg APS group, the 450 mg/kg GPS group, and the APS + GPS combination group (AG group), with 12 replicates per group and 4 squabs per replicate. The experiment lasted for 28 days. The results showed that final body weight tended to be higher in the APS, GPS, and AG groups, whereas breast width and breast depth were significantly increased in the GPS and AG groups (p < 0.01). The GPS and AG groups exhibited increased serum immunoglobulin A (IgA; p < 0.05) and immunoglobulin G (IgG; p < 0.01) levels, as well as reduced levels of pro-inflammatory cytokines, including interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α; p < 0.01). All treatments increased serum total antioxidant capacity (T-AOC; p < 0.01), while the AG group reduced malondialdehyde (MDA) levels and increased total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) activities (p < 0.01). Duodenal and jejunal T-AOC increased in all treatment groups (p < 0.01), and APS and AG increased ileal T-AOC (p < 0.01). However, intestinal MDA concentrations increased in several segments, indicating a complex and segment-specific oxidative response. The AG group also increased jejunal lipase activities (p < 0.05). Microbiome analysis suggested that Helicobacter was correlated with immune-related indicators, while Lactobacillus was identified as an important core genus in the microbial co-occurrence network. These findings suggest that dietary APS and GPS may regulate immune function, oxidative–antioxidant responses, intestinal function, and gut microbial composition, thereby supporting physiological adaptation in early-weaned squabs. Full article

The cryopreservation of pre-implantation embryos has become routine in medically assisted reproduction (MAR), and the proportion of frozen embryo transfers has steadily increased in recent years. Because cryopreservation through either slow-cooling protocols or ultra-rapid vitrification requires potentially cytotoxic cryoprotective agents to prevent uncontrolled and detrimental ice crystal formation, the safety of these procedures must be carefully considered. Evidence from human epidemiological studies, including retrospective and prospective controlled studies, and data from national patient registries indicate that children born after frozen embryo transfer have a higher birth weight than those born after spontaneous conception and have an increased risk of rare genomic imprinting disorders, such as Beckwith–Wiedemann, Silver–Russell, or Prader–Willi syndrome. Encompassing not only reversible DNA methylation patterns established during gametogenesis, but also the timed abundance and availability of transcripts and proteins required to establish or maintain epigenetic marks throughout development and differentiation, as well as persistent or transient post-translational histone modifications and non-coding RNAs, the epigenome may be particularly sensitive to cryopreservation. Importantly, epigenetic regulation is highly complex. Alterations of the epigenome at any developmental stage are often not monocausal, do not necessarily result in immediate disturbances in the pre-implantation embryo, and are unlikely to operate through simple all-or-nothing mechanisms; however, they may have long-lasting effects at later developmental stages. To make matters even more complex, differences between species in terms of epigenetic regulation or lineage differentiation are well known and translation from animal model systems to humans must be considered with caution. More recently, epigenetic regulation by non-coding RNAs has also come into focus, as these molecules are crucial, either directly or indirectly, for gene expression, translation, and protein biosynthesis during development. Therefore, assessing potential adverse effects of cryopreservation on the entire epigenome remains a major challenge, particularly because little is known about indirect factors, such as post-translational histone modifications and non-coding RNAs. In this review, we focus on the potential influence of the cryopreservation of pre-implantation embryos on the epigenetic profile in humans and animals. Specifically, we consider DNA methylation of imprinted genes and global DNA methylation; post-translational histone modifications; the abundance and availability of transcripts and proteins required to establish, maintain, or protect epigenetic patterns; and the presence of non-coding RNAs involved in epigenetic control. Full article

Non-canonical nucleic acid structures such as G-quadruplexes (G4s), i-motifs, triplexes, junctions, and structured RNA domains offer coordination environments that differ fundamentally from those of canonical duplex DNA. This review is deliberately G4-centred, because DNA G4s currently provide the most mature mechanistic and biological evidence for noble-metal recognition, while i-motifs, quadruplex–duplex hybrids, junctional structures, R-loops, Z-DNA/Z-RNA, and structured RNA remain emerging or less extensively validated target classes. The discussion addresses how platinum, gold, palladium, and silver complexes recognize these architectures through combinations of coordination chemistry, pi-stacking, electrostatics, scaffold-dependent shape complementarity, and metal-mediated base pairing. A further distinction is made between direct structural recognition, cellular target engagement, and downstream phenotypic responses, emphasizing where causality has been experimentally demonstrated and where it remains inferential. Particular emphasis is placed on G-quadruplexes in telomeric, promoter, and mitochondrial contexts, while i-motifs, junctional DNA, hybrid DNA/RNA structures, and structured RNA are treated as expanding but less mature areas of investigation. The review also critically addresses selectivity, resistance, delivery, and translational challenges, highlighting how the concept of functional architectures can help unify structural chemistry with pathway-level biology in the design of next-generation metallodrugs. Full article

The development of multifunctional and lightweight materials is increasingly shaping the design of next-generation sensing and communication systems for space applications. In CubeSat platforms, severe constraints on mass, volume, and structural complexity motivate the integration of antenna functionalities directly onto load-bearing structures. In this context, printed electronics, particularly inkjet-printed conductive materials, offer new opportunities for creating adaptive, flexible, and structure-integrated devices that support both sensing and communication functionalities. This work investigates the electrical performance of inkjet-printed conductive materials for structure-integrated patch antennas. Two silver-based inks and one carbon-based ink were deposited on fiberglass-reinforced epoxy substrates and electrically characterized over a temperature range from −20 °C to 50 °C, representative of CubeSat operational conditions. The silver-based inks exhibited electrical conductivities in the range of 10⁶ S/m with limited variation (<10%) under thermal cycling, whereas the carbon-based ink remained below 10¹ S/m, even after multilayer deposition, indicating insufficient performance for this application. Based on these results, the best-performing silver ink was selected to fabricate a proof-of-concept patch antenna directly on an S2-glass/epoxy structural substrate. The proposed approach demonstrates the feasibility of integrating conductive inkjet-printed layers onto composite structural substrates intended for future structure-integrated antenna applications in CubeSat platforms, offering a pathway toward mass-efficient, low-profile, and highly integrated communication structures. Full article

This study reports the green synthesis of silver nanoparticles (AgNPs) using Salvia tomentosa L. leaf extract, and evaluates their physicochemical characteristics and biointerfacial performance, including DNA interaction, antibacterial activity, and antioxidant capacity. AgNP formation was confirmed by UV-Vis spectroscopy through a surface plasmon resonance band at 472 nm. SEM imaging showed predominantly spherical particles with sizes of 30–80 nm and a zeta potential of −17.3 mV, and EDX verified the elemental presence of silver. FTIR spectra indicated that plant-derived biomolecules, particularly phenolics, contributed to the reduction and capping/stabilization of AgNPs. XRD analysis confirmed a crystalline face-centered cubic structure. The AgNPs exhibited moderate, spontaneous binding to DNA (Kb ≈ 1.07 × 10⁴ M⁻¹), characterized by pronounced hyperchromism without evidence of intercalation. Competitive fluorescence assays supported a predominantly non-intercalative, surface-associated interaction with minor groove perturbation, while agarose gel electrophoresis indicated preserved plasmid integrity and no extensive strand cleavage. Collectively, these results suggest reversible and structurally non-destructive AgNP–DNA complexation, indicating their potential for nucleic acid-related nano-biointerface studies, while further investigations are required to evaluate their suitability for biomedical applications. The biosynthesized AgNPs showed enhanced antibacterial activity against Gram-positive (Bacillus cereus) and Gram-negative (Pantoea agglomerans) bacteria compared with the leaf extract, whereas AgNO₃ produced the strongest immediate effect, consistent with rapid Ag⁺ release. Antioxidant activity assessed by DPPH and ABTS assays showed strong radical-scavenging activity for the extract, in line with its high total phenolic content (206.2 mg GAE/g). Although AgNPs displayed lower phenolic content (164.2 mg GAE/g) and reduced antioxidant activity than the extract, they retained moderate scavenging capacity, indicating effective surface functionalization by phytochemicals. Overall, S. tomentosa leaf extract-capped AgNPs combine defined physicochemical features with non-destructive DNA association and antibacterial efficacy, underscoring their promise as phytochemical-functionalized nano-biointerfaces for antimicrobial and related biointerface applications. Full article

The literature collected from various search engines and high-quality scientific databases reveals that amino acid (AA)-functionalized nanoparticles have emerged as a promising field for selective detection and remediation of heavy metals (HMs). Among the various nanoparticles (NPs), gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) have drawn considerable attention, attributed to their unique optical, catalytic, and surface plasmon resonance properties. Functionalization with amino acids significantly enhances nanoparticle stability, biocompatibility, and metal-binding affinity through diverse functional groups. AA-functionalized AuNPs, including glycine, cystine, leucine, methionine, tyrosine, aspartic acid, histidine, and lysine-capped systems, exhibit tunable selectivity toward heavy metal ions. Bifunctionalization strategies further enhance sensitivity by inducing nanoparticle aggregation or signal amplification. Beyond single amino acids, polypeptides and protein-functionalized AuNPs offer enhanced molecular recognition and multivalent binding, expanding their applicability in complex matrices. Similarly, amino acid-functionalized AgNPs, such as those capped with similar amino acids stated above, exhibit strong interactions with heavy metals, AA bifunctionalization, and bimetallic nanoparticles (BNPs), particularly amino acid-functionalized Au–Ag systems, which combine the advantages of both metals, leading to improved sensitivity, selectivity, and signal strength. Although these advances have been made, a major gap remains in the systematic comparison of different amino acids, peptides, and bimetallic systems under real-world conditions. This gap can be addressed by standardized testing methods, clearer structure–function relationships and combined experimentation to guide the rational design of more efficient AA-functionalized nanoparticles. Full article

Telkari is a decorative art based on the handcrafting of fine silver wires. Identifying Telkari jewelry is quite challenging due to its diverse designs and styles. Recognizing these jewelry items, which come in thousands of varieties, requires experts in Telkari. In this study, we propose an approach for Telkari recognition using computer vision techniques, aiming to simulate the analysis of Telkari jewelry by Telkari experts. In the first stage, we created a dataset of Telkari by collecting images of Telkari products produced by Telkari masters in the Midyat district of Mardin, Turkey. In the second stage, the performance of the MobileNetV2 and ResNet50 deep learning models was examined using both direct classification and hyperparameter-tuned approaches. Furthermore, the feature vectors extracted from the deep learning models were trained using traditional machine learning algorithms, SVM, KNN, XGB, and RF, after selecting discriminative features with ANOVA. Among the hyperparameter-tuned models, ResNet50 outperformed MobileNetV2. Among the hybrid approaches, the SVM model trained on features obtained from ResNet50 achieved the highest performance with an overall accuracy of 99.56%. Furthermore, the interpretability techniques GradCAM, t-SNE, and LIME were used to examine the model’s decision-making processes, confirming that they focused on relevant visual regions and that predictions were based on the complex interactions among multiple features. In conclusion, this study provides a robust methodology for developing a highly accurate and transparent classification system for fields such as cultural heritage preservation and digitization. Full article

Raman spectroscopy (RS) provides detailed information on molecular structure but remains challenging for low-scattering proteins in complex media. Myelin basic protein (MBP) is a key structural component of central nervous system myelin and a clinically relevant molecule in demyelinating disorders; however, to the best of our knowledge, its Raman signature in solution has not been reported. In this work, Raman and surface-enhanced Raman spectroscopy (SERS) were employed to characterize purified human myelin basic protein (MBP) in aqueous solution and cerebrospinal fluid (CSF). Quasi-spherical silver nanoparticles were used as SERS elements, yielding enhancement factors of 10⁵ and increasing sensitivity to MBP-associated spectral changes at low concentrations. The MBP spectrum exhibited vibrational modes primarily associated with amide II and amide III bands, as well as aromatic side-chain contributions. Comparative analysis of MBP, CSF, and MBP-spiked CSF samples revealed significant spectral overlap, limiting discrimination based solely on peak positions. To overcome this limitation, spectral correlation and band-intensity-ratio analyses were applied, revealing reproducible trends associated with increasing MBP content. While individual MBP bands are not exclusive, the observed spectral patterns demonstrate the sensitivity of RS and SERS to MBP-induced spectral changes in CSF. These findings should be interpreted as a proof-of-concept in a single-donor CSF matrix. Full article

This essay examines the visual culture of what might be termed “the ecology of silver” between 1492 and 1710 in relation to colonialism on both sides of the Atlantic, with particular attention to both its shiny allure and the blind spots that that shininess produces. It focuses on three inter-related areas: depictions of Potosí, the great silver mountain in viceregal Peru; silver’s shine in European elite material culture; and the deployment of silver in celebrating the Spanish monarchy in viceregal Sicily, part of its empire within Europe. Current scholarship on early modern silver bifurcates between historical, political, and anthropological studies of silver’s extraction in the Americas and colonialism on one hand and a celebratory art historical scholarship focused on high-end European silver goods on the other. Scholars have energetically examined its extraction, the global trade in bullion, the rise of capitalism that it fed, and the wars that it fomented and paid for, but they stop short of inquiring into the ends to which silver was deployed within Europe and Asia beyond the naming of the principal ports. Meanwhile, studies of silver in Europe are overwhelmingly tightly drawn and connoisseurial, often with no reference to where the silver came from, let alone the circumstances of its extraction, transport, or even its effects. This split is due partly to a prevalent notion that silver’s value is inherent, objective, and caused by “rarity”; and it is partly due to art history’s unswerving identification with the rich and powerful. Such approaches overlook silver’s remarkable material and alchemical qualities and ignore its capacity to turn grubby profit into charismatic sparkle, which simultaneously drove the ecological and environmental damage and exonerated its profiteers. Early modern silver linked environmental destruction, colonialism, genocide, and coloniality to high culture, making it a particularly relevant topic for art historical analysis in this context. But more than that silver entwined them in complex, convulsive, and transformative ways, turning imperialism, violence and exploitation into beauty, shimmer and cultural sophistication. Hence, this essay insists on the centrality of imperial issues in the Old World as in the New, underscoring colonial dynamics within metropolitan culture while critically examining the work of seduction of art. The paradoxical quality of shine is the lens through which is seen the relation between violent coloniality and the allure and ecology of early modern silver. Full article

This paper examines the energy potential of silver fir (Abies alba Mill) and Norway spruce (Picea abies (L.) Karst) trees across three tree crown defoliation degrees (TCDDs): healthy, severely defoliated (61–99%) and dead. The study was conducted in the area of the Forest Administration Delnice, Management Unit »Milanov vrh«, in the Republic of Croatia. Field measurements were conducted on 83 silver fir trees and 114 Norway spruce trees to determine the mass of live and dead branches per tree and to collect samples of wood, bark, main live and dead branches, and side live and dead branches (in total, 813) for further laboratory analyses. Further, differences in wood basic density, moisture content, ash content, net calorific value, and carbon, hydrogen, nitrogen, and sulfur content across TCDD classes were also determined. For both tree species, wood basic density across TCDDs decreased as follows: severely defoliated trees > healthy trees > dead trees. Regression analyses showed that the largest masses of branches occurred on healthy silver fir trees (R² = 0.48), followed by severely defoliated (R² = 0.41) and dead trees (R² = 0.46). The same trend in determined total branch mass per tree was observed for Norway spruce trees, where the coefficient of determination was highest for dead trees (R² = 0.72), followed by severely defoliated (R² = 0.69) and healthy (R² = 0.61) trees. A negative correlation between moisture content and TCDD class was observed for wood, bark, and live branches. The highest net calorific value was found for side live branches for both researched species, and only the net calorific value of side live branches of Norway spruce was statistically significantly different across TCDD classes. Overall, this study showed a negative impact of TCDD on the amount of available tree residues (branches) that could be utilized as a solid biofuel. Furthermore, the results of the laboratory analyses were ambiguous, increasing the complexity and heterogeneity of the wood material and underscoring the need for further investigation. Full article