Search Results (3,153)

Archaeological bone artifacts frequently exhibit diminished mechanical integrity as a result of organic matrix degradation. Under adverse environmental conditions, such artifacts are particularly susceptible to surface cracking and disintegration into powder. It is urgently necessary to develop protective materials that possess high permeability, strong reinforcing power and good compatibility. This study evaluated the protective performance of a novel Acrylate Metal Complex (AMC) and two conventional commercial consolidants (acrylic resin Paraloid B72 and ethyl silicate-based material Remmers 300) on fragile bone artifacts. Using simulated samples resembling bone artefacts, a systematic evaluation was conducted to assess the penetration, mechanical reinforcement efficacy, microstructural modifications, chromatic impact, and aging resistance of three consolidants. The results indicate that AMC demonstrates optimal permeation capability and can significantly enhance the surface hardness of bone specimens, achieving an increase of 7.7%. The colorimetric changes observed in all three reinforced materials following treatment remained within acceptable limits (ΔE* < 1.5). Accelerated aging tests—including 300 h of UV irradiation and 30 cycles of alternating dry-wet conditions—demonstrated that bone-mimetic composites reinforced with AMC exhibited significantly superior aging resistance relative to those treated with B72 and Remmers 300. In the actual application verification of the archaeological bone relics, the surface hardness of the reinforced AMC increased by 10%, the wave velocity increased by 14.8%, and there was no glare or crust on the surface. Comprehensive comparison shows that AMC outperforms traditional commercial materials in key performance indicators, demonstrating great potential as a next-generation bone relic conservation material. Full article

To address the issues of operational complexity, long duration association, and reliance on specialized equipment with existing detection methods for Vibrio parahaemolyticus, this study established a rapid detection method for V. parahaemolyticus in exported aquatic products based on the domestically developed Enzymatic Recombinase Amplification (ERA) technology. To target the thermolabile hemolysin gene (tlh) and the iron-regulated virulence regulatory protein gene (irgB) of V. parahaemolyticus, highly specific ERA primers and probes were designed and screened. Two detection platforms, a colorimetric method and a fluorescent method, were developed. Method validation results showed that this detection system achieved specific amplification for all 30 tested V. parahaemolyticus strains, with no cross-reactivity observed with 30 other common foodborne pathogenic bacteria. The detection sensitivity for both the fluorescent and colorimetric methods reached 10⁻¹ ng/μL, with a minimum detection limit of 10 CFU/25 g for artificially contaminated samples. The entire detection process, including sample preparation, requires only approximately 20 min—significantly faster than traditional culture (24–72 h) or even conventional PCR methods. Collaborative validation across five independent laboratories confirmed excellent reproducibility, with inter-laboratory agreement yielding a Kappa coefficient of 0.98. The ERA method operates at a low, constant temperature (37–39 °C), eliminating the need for thermal cyclers. When combined with portable isothermal amplification devices and visual (colorimetric) readout, it offers a distinct advantage in terms of speed, cost-effectiveness, and suitability for resource-limited or field settings compared to existing PCR-based or culture-based platforms. This method is simple to operate, rapid, sensitive, and highly suitable for on-site application, providing a reliable and practical technical solution for the rapid screening and risk monitoring of V. parahaemolyticus in exported aquatic products. Full article

This study systematically investigated the characterization of 2Fe-CDs/12Mn-CeO₂ composites and the colorimetric sensing properties of H₂O₂, glucose (Glu), and glutathione (GSH). The morphology, structure, and optical properties of the 2Fe-CDs/12Mn-CeO₂ composite were analyzed in detail by XRD, FT-IR, SEM, TEM, XPS, and Raman spectroscopy, and its formation was supported by multiple complementary characterization techniques. The catalytic efficiency (kcat/Km) of the nanozyme is 152-fold higher than natural HRP under optimal conditions and remains 59-fold higher even after temperature normalization to 25 °C. In the colorimetric sensing experiments, the detection limits of Fe-CDs/Mn-CeO₂ were 0.21 μM, 2.7 μM, and 0.63 μM for H₂O₂, Glu, and GSH, respectively. Rapid and accurate determination of the concentrations of these biomolecules can be achieved by observing the color changes after Fe-CDs/Mn-CeO₂ reaction with the objects to be measured. The experimental results show that Fe-CDs/Mn-CeO₂ have high sensitivity and selectivity for H₂O₂, Glu, and GSH, which provides a solid theoretical and experimental basis for the application of Fe-CDs/Mn-CeO₂ in the field of biosensing and medical diagnosis. Full article

Background: Ovarian cancer (OC) is characterized by aggressive progression, high metastatic potential, and frequent resistance to conventional chemotherapy, highlighting the need for novel combination-based therapeutic strategies. Metformin has emerged as a promising antineoplastic agent; however, its efficacy may be enhanced through combination with bioactive compounds. This study aimed to investigate the antineoplastic effects of metformin in SKOV3 human OC cells and to evaluate whether these effects could be potentiated by boric acid (BA) and resveratrol, with particular emphasis on their modulatory impact on key inflammatory and tumor-associated biomarkers, including interleukin-17 (IL-17), nuclear factor kappa-B (NF-κB), and midkine (MDK). Methods: SKOV3 cells were treated with metformin, BA, and resveratrol as monotherapies or in combination. Cell viability was assessed using a colorimetric assay, while migratory capacity was evaluated by wound healing analysis. The expression levels of IL-17, NF-κB, and MDK were quantified in cell lysates, and p21 protein expression was analyzed by immunocytochemistry. Results: All treatments induced concentration- and time-dependent reductions in cell viability. Combination treatments, particularly metformin with boric acid or resveratrol, produced more pronounced inhibitory effects on cell survival and migration compared with single-agent treatments. Inflammatory and tumor-associated biomarkers, including IL-17, NF-κB, and MDK, were significantly modulated following treatment. Additionally, increased p21 expression was observed in treated cells, indicating enhanced cell cycle regulatory activity. Conclusions: These findings indicate that BA and resveratrol enhance the antineoplastic activity of metformin in SKOV3 OC cells by suppressing proliferative and migratory capacities and modulating inflammatory mediators such as IL-17, NF-κB, and MDK. However, since toxicity assessments in non-cancerous cells were not performed, the safety profile of this combination remains unclear and requires further investigation in non-cancerous models. Full article

Different methods are used today for polysaccharide quantitation, including HPLC and various colorimetric assays. Among these, the anthrone-sulfuric acid assay (anthrone assay) is popular when the sample matrix is suitable, such as in purified polysaccharides and monovalent bulk conjugate components of glycoconjugate vaccines. While relatively safe, quick, and affordable, the anthrone assay requires significant operator time to complete and is not suited to high-throughput processing. Furthermore, the anthrone-sulfuric acid reagent presents a unique challenge to automation efforts due to its corrosive properties. Reported here is an automated anthrone assay via a liquid handling system (LHS). Twenty-three serotypes of pneumococcal (PNU) polysaccharide were quantified with the traditional anthrone assay and subsequently analyzed using the anthrone LHS method. The anthrone LHS method was evaluated for accuracy compared to the manual method and later validated according to ICH Q2 (R2) guidelines. To our knowledge, this is the first fully unattended and corrosion-mitigated anthrone assay validated under ICH Q2 (R2), capable of overnight batch operation. The developed assay can quantify polysaccharides with an accuracy of 81–115%, is precise to a coefficient of variation of <7.0%, and is linear between 30 and 650 µg/mL range (R² ≥ 0.993). The assay can process eight samples per hour, can be utilized in overnight operation, and completes all pipetting, incubation, and data export steps automatically. Full article

The rapid detection of zinc in different aqueous matrices is very relevant. For example, a Zn²⁺ level above ca. 50 µM affects drinking water quality, while levels below ca. 25 µM in urine are related to higher probability of prostate cancer. Herein, a simple and rapid qualitative colorimetric sensor for the detection of zinc ions in aqueous samples is developed. The sensor exploits the reaction between 1,5-diphenylthiocarbazone and Zn²⁺ to form colored chelates whose color changes with increasing Zn²⁺ concentration. The chelating agent has been immobilized in a dried form on various cellulose- and synthetic-based materials to obtain a sensor that can be used for in situ analysis. The procedure to obtain the colorimetric device is easy and straightforward. Moreover, it requires neither specialized personnel to perform the analysis nor specialized personnel for the interpretation of the analytical results. The analysis requires only 20 µL of sample, and a reliable colorimetric output is obtained within 10 min and is stable up to 30 min. The sensor allows Zn²⁺ visual detection in drinking water and urine without any sample pre-treatment with excellent efficiency and repeatability. Considering the ability to distinguish between Zn²⁺ concentrations equal to 0.5 and 2× the cut-off level, the sensor showed sensitivity and specificity of 100% for fortified tap water analysis and 100% sensitivity and 88.9% specificity for urine samples. The almost-perfect concordance with the reference atomic absorption spectrometer and the 94.1% accuracy demonstrated the sensor’s excellent potential to be applied for selective qualitative Zn²⁺ detection in real-life situations. Full article

Catalpol, one of the primary bioactive components in Rehmannia glutinosa, is an iridoid glycoside with significant pharmacological activities. To expand the microbial sources of catalpol, endophytic bacteria were isolated from R. glutinosa (cultivated in Jiaozuo, China) using the dilution plating method combined with vanillin–sulfuric acid colorimetric assay. High-performance liquid chromatography (HPLC) and liquid chromatography–mass spectrometry (LC-MS) were employed for screening and identification. The isolated strain was identified through morphological characterization and 16S rDNA gene sequence analysis, while single-factor experiments coupled with response surface methodology were utilized to optimize its fermentation conditions. Results indicated that the strain DH14 formed circular, cream-white, opaque colonies and was Gram-negative. It was identified as Brevundimonas olei. The optimal fermentation conditions were determined to be 190 rpm, pH 7.6, 31 °C, and 0% NaCl. Meanwhile, the results revealed a positive correlation between the pH of the fermentation broth and catalpol production. Under the optimized conditions, the maximum catalpol yield reached 0.142 mg/mL after 3 days of cultivation. This study provides a promising microbial resource and optimized fermentation parameters for the microbial production of catalpol. Full article

2,6-Dichlorophenolindophenol (DCIP) is a redox dye and colorimetric reagent previously shown to enable rapid quantification of laboratory cultures of oral microorganisms. DCIP is reduced by viable microbial cells, resulting in loss of its blue color that can be measured spectrophotometrically. Previous studies demonstrated that several strains of oral bacteria and yeasts grown in culture reduce DCIP, with significant correlations observed between increasing viable plate counts and DCIP reduction. The present investigation expanded upon these studies by evaluating DCIP as a method for assessing heterogeneous mixtures of oral microorganisms collected from human subjects. Oral rinse samples were obtained from 184 adults aged 18–70 years and analyzed for DCIP reduction and viable bacterial counts. DCIP reduction was observed in all oral samples, and viable bacterial counts spanning an approximately two-log range (~100-fold difference) demonstrated a statistically significant correlation with DCIP reduction (r = 0.74; p < 0.001). Nonviable organisms did not reduce DCIP, and no DCIP reduction occurred in the absence of bacteria. These results support DCIP reduction as a practical, low-cost platform for estimating viable oral microbial burden, with the additional advantage of a visually interpretable colorimetric readout. Full article

The valorization of agro-industrial by-products is a sustainable approach to recovering high-value bioactive compounds. In this study, Opuntia ficus-indica (L.) Mill. seed press residues were investigated as a source of phenolic and flavonoid compounds using microwave-assisted extraction (MAE). A multi-step optimization strategy was implemented, combining preliminary single-factor experiments (OVAT), response surface methodology based on a Box–Behnken design (BBD), and machine learning modeling using K-nearest neighbors coupled with the dragonfly algorithm (KNN_DA), followed by desirability-based validation. The effects of ethanol concentration (50–100%), microwave power (400–800 W), extraction time (2–4 min), and liquid-to-solid ratio (30–50 mL/g) were evaluated on Folin–Ciocalteu reducing capacity (FCRC), AlCl₃ complexation response, and antioxidant activity assessed by DPPH radical scavenging and reducing power assays. Optimal conditions were identified at 50% ethanol, 800 W microwave power, 4 min extraction time, and a liquid-to-solid ratio of 47.28 mL/g. Under these conditions, FCRC reached 376.85 ± 0.23 mg GAE/100 g DW and 49.16 ± 0.33 mg QE/100 g DW for AlCl₃ complexation response, with prediction errors of 2.80% and 0.82%, respectively. The optimized extracts exhibited enhanced antioxidant activity. These findings confirm MAE as a rapid and environmentally friendly technique and highlight the predictive performance of the KNN_DA model for process optimization. Full article

There is a growing interest in natural bioactive substances, particularly plant-derived secondary metabolites. Polyphenols constitute one of the largest and most significant groups of these metabolites. Rosebay willowherb (Epilobium angustifolium) is well known in traditional medicine and can serve as a reference species for studying its less-known congener, hairy willowherb (E. hirsutum), thereby expanding knowledge of medicinal plants. This study aimed to quantitatively estimate and compare the total phenolic content (TPC) and total flavonoid content (TFC) in the leaves and flowers of Epilobium angustifolium and E. hirsutum, and to identify populations with the highest phytochemical potential. TPC and TFC were quantified using the Folin–Ciocalteu and aluminium chloride (AlCl₃) colorimetric assays, respectively, with resulting values regarded as estimates due to the non-specificity of these assays. The results showed that, in terms of TPC, E. angustifolium leaves accumulated 132 ± 3.4 mg_GAE/g (milligrams of gallic acid equivalent per gram of dry plant mass), exceeding those of E. hirsutum by 16.8%; in flowers, the respective values were 153 ± 3 mg_GAE/g, a difference of 1.3%. Regarding TFC, E. angustifolium leaves contained 25 ± 1.4 mg_RE/g (milligrams of rutin equivalent per gram of dry plant mass), which was 20% lower than in E. hirsutum, whereas its flowers accumulated 44 ± 1.4 mg_RE/g, representing a 63% higher content compared with E. hirsutum. The study may contribute to the selection of the Epilobium populations for genetic resource conservation and sustainable utilisation. Full article

This study evaluates the effectiveness of laser cleaning techniques for the non-contact removal of unwanted deposits from the surface of contemporary urban mural paintings. Two sets of mock-up samples, painted with popular graffiti spray paints on lime-based plaster, and artificially contaminated, were subjected to various cleaning procedures using Nd:YAG lasers operated in Q-switched (QS), long Q-switched (LQS) or short free-running mode (SFR). A multi-analytical approach—including X-ray fluorescence spectroscopy (XRF), Fourier-transform infrared spectroscopy (FTIR), colorimetry, and hyperspectral imaging (HSI)—was used to identify pigments and binders, and to evaluate cleaning efficiency and pigment preservation. XRF and FTIR were useful in understanding the composition of the sprays, while colorimetric ΔE values quantified cleaning efficiency and potential damage, and hyperspectral reflectance and LSU (linear spectral unmixing) abundance maps provided spatial distribution insights into contaminant removal and pigment preservation. The results demonstrate that laser cleaning effectiveness and selectivity are strongly dependent on the operational regime and fluence. In particular, long Q-switched laser irradiation at moderate fluence levels achieved effective contaminant removal with minimal chromatic and chemical alteration of the original paint layers. These findings support the development of tailored, sustainable, and non-contact laser cleaning protocols for the conservation of contemporary urban murals and contribute to the establishment of objective, multi-parameter criteria for evaluating cleaning outcomes in street art conservation. Full article

Monoacylglycerol lipase (MAGL) is a key regulator of lipid signaling networks implicated in tumor progression and represents an attractive anticancer target. To combine MAGL inhibition with potentially enhanced uptake by highly glycolytic cancer cells, we designed glycoconjugated analogs of a N-benzoylpiperidine MAGL inhibitor scaffold bearing a glucopyranose unit. An alkyne-functionalized benzoylpiperidine intermediate was prepared and coupled to azido sugars through a CuAAC “click” reaction to afford two triazole-linked glycoconjugates. In a colorimetric assay on human MAGL, the new compounds 17 and 18 inhibited the enzyme with IC₅₀ values of 43.3 and 68.8 μM, respectively, confirming compatibility with MAGL inhibition albeit with reduced potency versus reference triazole-substituted benzoylpiperidine 13 (IC₅₀ = 4.1 μM). In PANC-1 pancreatic cancer cells, both glycoconjugates were inactive in high-glucose medium, but displayed antiproliferative activity under low-glucose conditions (GI₅₀ 17 = 129 μM; GI₅₀ 18 = 12 μM), consistent with glucose-dependent uptake/competition. Overall, these first-in-class MAGL-targeting glycoconjugates provide a starting point for optimizing dual MAGL inhibition and metabolically driven cellular selectivity. Full article

Human milk is the optimal standard for neonatal nutrition, particularly for preterm infants. Several conditions associated with oxidative stress (OS) may be transmitted from mother to infant through milk, making the preservation of milk quality essential. When maternal milk is unavailable, donor human milk (DM) is commonly used and treated with Holder pasteurization (HoP) to ensure microbiological safety, although this process may affect bioactive components. This study aimed to evaluate the impact of HoP on OS biomarkers, specifically total antioxidant power (TAP) and 15-F2t-isoprostane, using colorimetric and ELISA methods as cost-effective alternatives to analytical gold standards. Twenty paired DM and HoP samples from the Human Milk Bank of Sant’Anna Hospital (Turin, Italy) were analyzed. No significant differences were observed in TAP levels between DM and HoP samples. In contrast, 15-F2t-isoprostane concentrations were significantly lower in DM compared to pasteurized milk (3.16 (1.59–5.27) vs. 0.76 (0.62–1.54), p-value < 0.001). This reduction remained consistent after stratification by sampling day. These findings suggest that HoP may reduce oxidative stress markers in donor milk, potentially limiting neonatal exposure to maternal oxidative imbalance. Although this effect could offer protective benefits for vulnerable preterm infants, further studies are needed to clarify the clinical implications of HoP on redox status and neonatal outcomes. Full article

The colour matching of ceramic restorations is sensitive to ceramic thickness, ceramic optical properties, the tooth region, the tooth/substrate basis colour, and the shade of the bonding agent. This in vitro study evaluates the influence of substrate darkening, resin cement shade and zirconia thickness on the final colour of monolithic Prettau^®2 zirconia restorations. An in vitro factorial design was used combining four resin substrates simulating increasing darkening (ND6–ND9), three shades of dual-cure resin cement (universal, transparent, white opaque) and three zirconia thicknesses (0.5, 1.0, 1.5 mm) of Prettau^®2 zirconia. Standardized photographs were taken under controlled conditions, and CIELAB coordinates (L*, a*, b*) were obtained in Adobe Photoshop. Colour differences relative to the Prettau^®2 A1 shade tab were calculated as ΔL*, Δa*, Δb* and ΔE*. An additive linear model on ΔE* and a main-effect MANOVA on ΔL*, Δa* and Δb* were fitted to assess the impact of each factor. The mean ΔE* was 6.67 ± 2.66, and all but two specimens showed a clinically perceptible colour difference (ΔE* > 2.7) from the A1 shade tab. Substrate shade accounted for 38.4% of the explained variance in ΔE*, cement for 27.6% and zirconia thickness for 6.7%. MANOVA confirmed significant multivariate effects of substrate and cement, but not of zirconia thickness. Translucent monolithic zirconia showed limited ability to reproduce the A1 reference shade over darkened substrates. Substrate shade was the main determinant of colour mismatch, followed by resin cement, whereas zirconia thickness within 0.5–1.5 mm played a minor role. White opaque cement reduced ΔE* and brought the final shade closer to A1, but residual mismatches often remained clinically relevant. These findings highlight the need to control and, when possible, modify the underlying substrate and to select high-opacity cements when shade matching is critical. Full article

Seafood processing generates large volumes of by-products that are often underutilized despite their potential as sources of high-value bioactive lipids. In this study, a hybrid process integrating microwave (MW) pretreatment with Soxhlet (SOX) extraction was developed and optimized to intensify the recovery of astaxanthin (ASX)- and ω-3 PUFA-rich oil from green tiger shrimp (Penaeus semisulcatus) residues. Response surface methodology (RSM) comprising 22 experimental runs was applied to optimize key MW process variables, including power (100–400 W) and irradiation time (30–90 s). Both factors significantly influenced oil yield, with optimal operating conditions identified at 400 W and 75 s. MW pretreatment promoted structural disruption of shrimp shells, as confirmed by scanning electron microscopy, thereby enhancing solvent penetration and mass transfer. Solvent selection further affected extraction performance: hexane:isopropanol (1:1, v/v) achieved the highest oil yield (3.86 g/100 g dry weight), while hexane:acetone produced extracts with the highest ASX concentration (1032.24 µg/g oil), ω-3 PUFA content (29.85%), and antioxidant activity (93.30% DPPH scavenging). Colorimetric analysis supported these results, with increased redness (a* = 18.12) correlating with ASX enrichment. Overall, this integrated MW-SOX process represents an effective process-intensification strategy for sustainable shrimp waste valorization and production of bioactive lipid fractions. Full article