Search Results (1,407)

This study evaluated the ability of filamentous fungi to biosynthesize silver nanoparticles (AgNPs). The nitrate reductase activity of the selected fungi, considered a key enzyme involved in AgNP biosynthesis, was assessed as a selection criterion. AgNPs were mycosynthesized using Fusarium equiseti AM-0197, F. cerealis AM-0206, F. oxysporum AM-0192, Alternaria scrophulariae AM-0187, and Aspergillus sp. (1-HSF-08 and 3-HSF-02) isolates. The synthesized AgNPs were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Zeta potential analysis. In all cases, spherical AgNPs were obtained, with maximum absorption peaks ranging from 400 to 420 nm. XRD analysis demonstrated a face-centered cubic crystalline structure, whereas Zeta potential measurements revealed a negative surface charge. FTIR analysis indicated the presence of organic functional groups on the nanoparticle surface acting as capping agents. The antibacterial activity of the synthesized nanomaterials was evaluated against reference strains of Escherichia coli and Staphylococcus aureus, two major foodborne pathogens, using the disk diffusion method. Inhibition zones ranged from 11.3 to 13.6 mm for E. coli ATCC 25922 and from 9.3 to 15.0 mm for S. aureus ATCC 43300. The minimum inhibitory concentration (MIC) determined by microdilution was 37.5 ppm for all AgNPs tested against E. coli, whereas MIC values against S. aureus ranged from 18.7 to 75 ppm depending on the nanoparticle evaluated. These findings demonstrate the effectiveness of mycosynthesized AgNPs as next-generation antibacterial agents for the in vitro control of foodborne bacterial pathogens. Full article

The results obtained in this paper extend several identities and interpolation formulas previously established for the numbers $y_{9,n}(\lambda ;a)$ to the higher-order case. We derive several explicit formulas, identities, and recurrence-type relations, and establish connections with well-known families of special numbers and polynomials, including the Apostol–Euler, Apostol–Bernoulli, Frobenius–Euler, Fubini, and Stirling numbers. We also define an interpolation function for the higher-order numbers and show that its values at negative integers recover these numbers up to an explicit normalization factor. Furthermore, we obtain a residue-class decomposition of this interpolation function and express it in terms of the structured generalized hypergeometric Hurwitz–Lerch-type specialization arising from the residue-class decomposition. Some special cases and structural properties of this zeta-type function, including its relation to the classical Lerch transcendent and a differential identity, are also investigated. As applications, we show that for $\lambda <-1$ the interpolation function governs the moments of a zero-truncated negative binomial distribution naturally attached to the higher-order numbers, and we derive the asymptotic behavior of these numbers from the dominant singularity of the generating function. Full article

In this study, corn protein hydrolysates (CPT) were prepared via enzymatic hydrolysis using Alcalase and Protamex, and then fractionated by ultrafiltration into three molecular weight components: >5 kDa (CPT1), 3–5 kDa (CPT2), and <3 kDa (CPT3). The physicochemical, functional and in vitro antioxidant properties of each component were systematically compared. Subsequently, glutamine peptides were isolated and identified from CPT3 using LC-MS/MS technology, and the structural characteristics of the identified peptides were further analyzed. The results showed that the ultrafiltration fractionation effectively enriched peptides with lower molecular weights from the enzymatically hydrolyzed products, which may potentially enhance their bioavailability. In addition, CPT3 exhibited superior foaming ability, emulsifying ability, dispersibility, and zeta potential, along with lower particle size and viscosity. Moreover, CPT3 exhibited strong antioxidant activity, with IC₅₀ values for ABTS radical scavenging and hydroxyl radical scavenging of 0.042 ± 0.003 mg/mL and 0.807 ± 0.019 mg/mL, respectively. Finally, 205 glutamine peptides were further identified from CPT3, and their structural characterization revealed that the identified peptides were rich in hydrophobic amino acids and had a high affinity for membrane proteins, which could serve as potential ligands for regulating intestinal barrier dysfunction. In summary, CPT3 possesses excellent functional properties and antioxidant activity, indicating its potential for development and application in functional and health foods. Full article

Background: Nanotechnology, a multidisciplinary science, has diverse applications in biology, physics, and medicine. SeNPs have only recently been explored. Understanding how modifications to SeNPs affect toxicity is beneficial for therapeutic applications. This study involves a novel one-pot chemical synthesis of SeNPs using biodegradable precursors, sodium selenite and ascorbic acid, at predetermined molar ratios, followed by polymer modification. Results: All SeNPs were spherical with favorable sizes (<114 nm) and polydispersity indices (PDI < 0.4). Functionalization improved the zeta potential of the SeNPs (−34.4 to 91.1 mV), together with a smaller size and increased PDI. Cytotoxicity was size-, cell-, dose-, and time-dependent. Functionalized SeNPs showed good cell viability at low concentrations, with toxicity at higher concentrations compared to the unmodified SeNPs. SeNPs synthesized using excess sodium selenite exhibited enhanced toxicity, particularly in neuroblastoma cells. SeNPs induced a significant increase in reactive oxygen species, with G1/G0 cell cycle arrest and apoptosis in human embryonic kidney cells, and necrosis and apoptosis in neuroblastoma and cervical carcinoma cells. Conclusion: The physicochemical and toxicity profiles of SeNPs depend on precursor molar ratios and polymer concentration. Hence, studying the released ions and the polymer-core association will enable the personalized synthesis of SeNPs to achieve the desired therapeutic outcomes. Full article

For $j=1,\dots ,r$, ${\alpha }_j\in (0,1)$ are such that the set $\{log(m+{\alpha }_j):m\in {\mathbb{N}}_0,j=1,\dots ,r\}$ is linearly independent over $\mathbb{Q}$. In the paper, we consider simultaneous approximation of a tuple of analytic functions by shifts $(\zeta (s+i\tau ,{\alpha }_1),\dots ,\zeta (s+i\tau ,{\alpha }_r))$ of the Hurwitz zeta-functions. We prove that the set of these shifts has a positive lower density in the interval $[T,T+H]$ for $T^{23/70}⩽H⩽T$. This extends the known results obtained for algebraically independent ${\alpha }_j$, $j=1,\dots ,r$, and with $T^{27/82}⩽H⩽T^{1/2}$. Moreover, we obtain a theorem on approximation of analytic functions by a linear combination of derivatives of Hurwitz zeta-functions. From that theorem, it follows that the number of zeros of that linear combination lying in the region $\{s\in \mathbb{C}:1/2<{\sigma }_1<{\sigma }_2<1,t\in [T,T+H]\}$ is greater than $cH$ with some $c>0$. This generalizes and extends the classical Voronin result for the function $\zeta (s,\alpha )$ with rational $\alpha$. For the proofs, a probabilistic approach is used. Full article

The zinc oxide nanoparticles (ZnO NP) were synthesized from zinc acetate using potato starch as a capping agent through alkaline sol–gel precipitation, without calcination. The produced nanoparticles were characterized using various analytical techniques, including UV–visible absorption spectroscopy (UV-vis), zeta potential analysis, dynamic light scattering (DLS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The ZnO NP exhibited an absorption maximum at 361 nm in the UV-vis spectrum, a z-average value of 138.1 nm and a zeta potential value of −23.8 mV as measured by DLS. The XRD pattern revealed distinctive diffraction peaks corresponding to the hexagonal wurtzite crystal structure characteristic of ZnO. FTIR analysis indicated that NP were capped with hydroxyl functional groups from the starch. The produced NP were quasi spherical, with sizes ranging from 20.7 to 38.1 nm and a mean particle size of 30.6 ± 5.1 nm. The potential application of ZnO NP as a photocatalyst was studied under UV light at 365 nm for the decolourization of tartrazine, a model azo food dye. The effects of varying concentrations of the catalyst (900–4500 µg/mL), tartrazine (2.5–10 µg/mL) and reaction time (30–120 min) on tartrazine removal were monitored using UV-vis at 426 nm. Under optimum conditions of 2700 µg/mL NP, 7.5 µg/mL tartrazine and a reaction time of 90 min, a 92% removal was achieved, with a rate constant (k) of 0.0135 min⁻¹. Additionally, the bactericidal activity of the NP against Escherichia coli and Bacillus subtilis was investigated using the resazurin broth method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against E. coli and B. subtilis were 2700 and 1800 µg/mL and 3600 and 2700 µg/mL, respectively. Thus, the current study highlights the calcination-free, potato starch-capped sol–gel synthesis and the bifunctionality of ZnO NP as a recyclable photocatalyst and a bactericide for the decolourization of dyes and pigments, as well as for the bacterial disinfection of food industry wastewater effluents. Full article

This study examined long-term changes in floristic composition and hydrological conditions following reforestation in the Yangju Forest Watershed Experimental Catchment, Republic of Korea. The analysis integrated repeated floristic surveys spanning approximately 50 years’ hydrological record from the same experimental catchment. Floristic surveys conducted at 9, 19, 26, 40, and 50 years after reforestation were analyzed using taxonomic and functional-group richness, Sørensen similarity, and zeta diversity, while streamflow records from 1984–2019 were evaluated using flow-duration curves (FDCs) and hydrological indices. Floristic richness increased from 54 taxa in the 1980s to 122 taxa in the 2020s (2.3-fold), with family- and genus-level richness increasing approximately 1.7- and 2.1-fold, respectively. Floristic similarity was highest between adjacent survey periods, whereas the greatest compositional turnover occurred between the 1980s and 2020s. Life-form and root-system representation increased over time, and wetland indicator species appeared approximately 25 years after reforestation. Hydrological change was characterized by increased runoff duration, a decreased flow-duration index, and a progressive increase in the dormant-season runoff ratio. Across four overlapping survey periods, plant species richness, the weighted root-system richness index (R), and wetland indicator species richness showed concurrent temporal patterns with hydrological variables, including fewer relatively low-discharge days and higher drought-flow discharge (Q355) and dormant-season runoff ratios. These long-term records reveal concurrent trajectories of floristic development and increasing streamflow persistence during five decades of forest development, demonstrating the value of integrating repeated floristic observations with long-term hydrological monitoring to evaluate forest restoration. Full article

The presence of polyvinyl chloride (PVC) micro/nanoplastics (MNPs) in water poses significant environmental and public health challenges, making their effective removal a pressing research problem. This study investigates the integration of air nanobubble pretreatment with conventional coagulation–flocculation–flotation as a strategy for PVC MNP remediation. The novelty of this study lies in validating nanobubbles as dual-function agents, serving simultaneously as chemical surface modifiers and physical flotation enhancers, within an integrated treatment process. Nanobubble exposure altered the physicochemical properties of PVC particles by reducing particle size, decreasing the magnitude of their negative zeta potential, and introducing oxygenated functional groups that enhanced surface reactivity and subsequent coagulation–flocculation. Among the tested coagulant/flocculant systems, polyaluminum chloride (PAC) combined with polyacrylamide (PAM) achieved the highest clarification efficiency, removing approximately 88–90% of turbidity. In comparison, Alum–PAM and ferric chloride (FeCl₃)–PAM systems exhibited lower removal efficiencies of 72–75% and 68–70%, respectively, under the tested flotation conditions. Flotation further promoted separation through nanobubble–particle and bubble–floc interactions. Fourier-transform infrared spectroscopy (FTIR) confirmed surface oxidation and changes in the interfacial chemistry of the recovered PVC-containing flocs. According to the results, the integrated process effectively combines physicochemical surface modification, electrostatic destabilization, polymer-assisted aggregation, and bubble-assisted flotation, with PAC–PAM under nanobubble pretreatment emerging as the most efficient configuration. Future research should focus on scaling to pilot/full-scale systems, testing real wastewater matrices, and evaluating long-term stability and energy efficiency. Full article

We use the Mittag-Leffler expansions of 1/${\sin }^{2}x$ and 1/$\sin x$, together with the Euler product for $\sin x$, to evaluate finite sums and one finite product of trigonometric functions over the equally spaced points $\alpha +k\pi /n$, $k=0,\dots ,n-1$. Differentiating one of these expansions l times and summing over the shifted points reduces the finite sum to a rearrangement of a single absolutely convergent series, evaluated at $n\alpha$; the same argument, applied at $\alpha =0$, gives closed forms for ${\sum }_{k=1}^{n-1}{f}^{\left(2l\right)}(k\pi /n)$ and its csc-analog in terms of the Riemann zeta function $\zeta (2l+2)$ for every nonnegative integer l from one computation. We show plainly that these $\zeta$-linked identities are this paper’s substantive content: the corresponding identities at $\alpha \ne 0$ reduce, once their $l=0$ case is known, to an elementary l-fold differentiation of either an elementary finite identity or an identity already published by Wang, and we do not claim these as new. We also note precisely that our closed forms sum a specific polynomial combination of powers of csc, not an isolated power, and we verify all identities numerically. We discuss the connection to $\zeta$ at even integers, one worked application to discrete Fourier transform spectral leakage, and which extensions (tangent/cotangent, hyperbolic) we expect to be routine versus which (elliptic, multidimensional) remain open. Full article

Background: Although intracellular delivery via endocytosis is a promising strategy for drugs acting in the cytosol or nucleus, many macromolecular therapeutics remain trapped within endosomal/lysosomal compartments, limiting efficient cytosolic delivery. In this study, we designed a novel functional hyaluronic acid (HA)-based polymer, HA–octahistidine (His8), by conjugating His8 to CD44-targeting HA, and evaluated its physicochemical properties, cellular uptake, and endosomal escape capability. Methods: HA–His8 was synthesized via 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS)-mediated coupling and characterized using ¹H NMR spectroscopy. Particle size and zeta potential were measured via dynamic light scattering, and buffering capacity was evaluated using acid–base titration. Cellular uptake and intracellular localization were investigated in CD44-high MDA-MB-231 and CD44-low MCF-7 cells via confocal laser scanning microscopy. Cytotoxicity was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: Successful conjugation of His8 was confirmed with a degree of substitution of 4.66 mol% relative to HA carboxyl groups. HA–His8 exhibited a nanoscale hydrodynamic diameter under physiological conditions, which increased under acidic conditions together with changes in zeta potential. HA–His8 exhibited higher buffering capacity than free His8 and was preferentially internalized by CD44-high MDA-MB-231 cells compared with MCF-7 cells. Compared with unmodified HA, HA–His8 exhibited lower colocalization with LysoTracker that decreased over time, indicating reduced retention within acidic vesicles. HA–His8 also exhibited low cytotoxicity over the tested concentration range. Conclusions: His8 modification alters HA intracellular localization while preserving CD44 targeting, thereby facilitating endosomal escape. These findings highlight HA–His8 as a potential platform for the cytosolic delivery of macromolecular therapeutics, including proteins, peptides, and nucleic acids. Full article

We consider the N-tuple Hurwitz-Lerch zeta function introduced by Srivastava and Choi, ${\zeta }_N(s,x,\lambda )={\displaystyle \sum _{k_1,\dots ,k_N\ge 0}}{\displaystyle \frac{{\lambda }^{k_1+\cdots +k_N}}{{(x+k_1+\cdots +k_N)}^s}}$, where N is a positive integer and $\lambda$ is a complex parameter. A central breakthrough in this work is the explicit reduction of the N-tuple function to a linear combination of single Lerch transcendents via a finite-difference identity, which naturally leads to sharp multiplication and inversion formulas. We further investigate the combinatorial structure of the underlying polynomial coefficients, establishing their symmetry, unimodality, log-concavity, and precise asymptotic behavior. As key applications, we derive new identities for higher-order Apostol-Euler and Apostol-Bernoulli polynomials. Our results unify and extend several known formulas. Full article

The aim of this study was to investigate the effect of PEG functionalization of hydrothermal carbon (HTC) on quercetin adsorption and desorption kinetics and, through that, evaluate the potential of functionalized HTC as a carrier for quercetin. Hydrothermal carbon (HTC) was synthesized using fructose as a precursor at a temperature of 160 °C. Structural and morphological analyses using X-ray diffraction and scanning electron microscopy (SEM) confirmed an amorphous carbon structure and microspherical particles with an average size of 5.6 µm. X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared (FT-IR) spectroscopy characterization revealed a surface enriched with hydroxyl and carboxyl groups, which facilitated successful PEG modification. Surface modification was further corroborated by a zeta potential shift from –26.4 mV to –16.4 mV. Cytotoxicity assays in MRC-5 and HeLa cell lines confirmed high biocompatibility, with cell viability remaining above 70%. Quercetin binding experiments showed that PEG functionalization increased binding capacity up to 14%, reaching 19.50 mg/g for PEG-functionalized fructose-derived carbon. Desorption kinetics followed a pseudo-second-order model, with the PEG-modified sample exhibiting significantly slower rates than the unmodified sample. These findings indicate that PEG functionalization can improve the adsorption/desorption properties of HTC compared with the pristine material, highlighting its potential as a promising, environmentally friendly, and efficient delivery system for quercetin. Full article

A magnetite–eggshell nanocomposite (Fe₃O₄@eggshell NC) was synthesized by green coprecipitation and evaluated for Cr(VI) removal from water. Passiflora ligularis peel extract, evaluated using a 2³ factorial design, served as the biogenic medium, while eggshell waste acted as the support. Characterization included X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning and transmission electron microscopy (SEM and TEM), Brunauer–Emmett–Teller (BET) analysis, zeta potential measurements, thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), and Mössbauer spectroscopy. The NC preserved Fe₃O₄ and CaCO₃ crystalline phases, contained nanoparticles averaging 18 nm, and exhibited oxygenated surface functionalities, a BET surface area of 134.93 m²/g, amphoteric behavior, and a predominantly superparamagnetic response suitable for magnetic recovery. Under conditions of pH 4, 180 rpm, 60 min, 0.15 g NC, and 50 mg/L Cr(VI), removal reached 75.98%. Kinetic data followed the pseudo-first-order model, whereas equilibrium data were well described by the Sips isotherm, with an estimated capacity of 50.81 mg/g. At the investigated initial concentration of 50 mg/L, adsorption was exothermic and favored at temperatures up to 308 K, and the material retained moderate reusability during the first three alkaline-regeneration cycles. Overall, Fe₃O₄@eggshell NC is a waste-derived, magnetically recoverable adsorbent with favorable Cr(VI) uptake under moderately acidic conditions. Full article

Let $\psi$ be the Chebyshev prime-counting function and $\pi \left(x\right)$ the number of primes up to x. The Chebyshev-prime condition $K\left(p\right)=\mathrm{li}\left(\psi \right(p\left)\right)-\mathrm{li}\left(\psi \right(p-1\left)\right)<1$ is not equivalent to the sign rule $\psi \left(p\right)-p>0$. We prove that its leading threshold is the midpoint correction $\psi \left(p\right)-p>{\displaystyle \frac{1}{2}}\log p$, with an explicit higher-order boundary, and define false Chebyshev primes through the resulting transition layer. Our main unconditional theorem shows that ordinary prime counting does not equidistribute logarithmic prime phases: for every nonzero integer combination $\tau$ of nontrivial zeta-zero ordinates, $\pi {\left(x\right)}^{-1}{\sum }_{p\le x}{p}^{i\tau }=x^{i\tau }/(1+i\tau )+o\left(1\right)$. By contrast, the logarithmically uniform weight $\log p/p$ restores finite-dimensional Haar equidistribution for rationally independent ordinates. This dichotomy motivates the weighted local-time statistic ${\mathcal{L}}_{+}\left(x\right)=2\sum p^{-1/2}$, summed over the layer primes $p\le x$. We show that the layer is exactly the one-sided slab $-T\left(p\right)<B\left(\log p\right)<0$ of the midpoint-centered field B, where $T\left(p\right)=\log p/\left(2\sqrt{p}\right)$, so that ${\mathcal{L}}_{+}$ is a bona fide occupation density. Assuming the Riemann hypothesis, linear independence, and a shrinking-window local limit hypothesis that we isolate as a separate open problem, we prove the one-directional Cesàro law ${\mathcal{L}}_{+}\left(x\right)/\log x\to f_B\left(0\right)$, where $f_B\left(0\right)$ is the value at the origin of the limiting density of B (numerically $f_B\left(0\right)\approx 1.828$). Independently, we prove shrinking-target occupation laws via coarea formulas: unconditionally for fixed windows, including for the finite zeta-derived field itself, and under uniform transversality for the diagonal window. The remaining obstacles are tangential crossings of that field and transfer to the prime-sampled diagonal window. Full article

The increasing demand for sustainable protein sources has stimulated interest in edible insects such as Tenebrio molitor (yellow mealworm) larvae. While probiotics supplementation has been explored to improve insect growth performance, its impact on protein quality and downstream processing remains poorly understood. This study investigated the combined effects of probiotic-enriched diet supplementation during larval rearing and post-harvest ultrasound-assisted extraction (UST) on the protein and lipid fractions of yellow mealworm larvae. Three probiotic strains, namely, Pediococcus pentosaceus (PP), Bacillus velezensis (BV), and Bacillus coagulans (BC), were incorporated into larval diets and compared with a standard diet (without probiotics). Protein extraction was performed by both alkaline solubilization–isoelectric precipitation, which served as a control, and ultrasound application for 5, 15, and 25 min. The results from the trial found effects of both probiotics and UST, as well as their interaction, on the protein yield, although an improvement in yield was not obtained with increased sonication, and the BV group produced the highest yield among the probiotic treatment groups. In addition to this, the study did not find any effects associated with ultrasound pretreatment or probiotics on proximate composition and color, except fat % and increased lipid co-extraction, especially at longer durations. Probiotics, on the other hand, showed an influence on the fatty and amino acid profile, while they interacted with UST to affect the extracts’ content. This study did not find any effects on particle size, but the zeta potential was affected by probiotic diet enrichment. Similarly, the free SH content was influenced by sonication, while both probiotics and UST played a role in hydrophobicity. Regarding the solubility, it was found to be pH-dependent and ranged from 0 to ≈90%. Importantly, this study found that probiotics did not have any effect on protein solubility; however, UST had an effect at pH 2 and 7 but not at pH 11. In terms of hydrophobicity, both factors and their interactions were found to have an effect. Moreover, this study could not determine any effects on the inherent fluorescence absorbance of protein molecules. Apart from this, FTIR analysis revealed β-sheet-dominated secondary structures (≈41–47%), with treatment-dependent shifts in α-helix and β-turn contributions. The heat enthalpies associated with denaturation and melting temperature were influenced by sonication, where probiotics could not confer an effect. Overall, this study might demonstrate the strain-specific improvement in protein yield and modulation of the physicochemical functionality, as well as the nutritive value of the protein. Both biological factors and ultrasound-assisted extraction processes can act together to tailor the physicochemical and functional properties of biofractions, but more studies are needed for process optimization. Full article