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Influence of avocado seed extract obtained by ultrasonic extraction on rebalancing skin staphylococc
No full textIntroduction: The skin microbiota, a complex and diverse community of
microorganisms residing on the skin's surface, has become an area of
increasing interest in the cosmetic industry. Disruptions to microbial balance
can lead to a decline in diversity and have been associated with several skin
disorders, including acne, atopic dermatitis, and psoriasis. Therefore,
maintaining a well-balanced skin microbiome is vital for preserving the
skin's barrier function and overall health. In this study, we investigated the
effect of avocado seeds extract (ASE) obtained by ultrasonic extraction on
skin microorganisms, the pathogenic Staphylococcus aureus and the
beneficial Staphylococcus epidermidis, aiming to assess its potential in
restoring a healthy skin microbiome balance. ..
Experimental and Quantum Mechanical Studies of Efficient Re(VII)/Mo(VI) Separation by a Magnetic Amino-Functionalized Polymer
No full textA previously synthesized and functionalized magnetic glycidyl methacrylate-based nanocomposite, mPGMT-deta, was tested as a sorbent for Re(VII) oxoanions in Mo(VI)-containing solutions. The effect of pH on the removal efficiency and the separation factor was examined in the range of 2 to 9. A maximum separation factor (βRe/Mo) of 8.85 was observed at pH 6. The nature of rhenium oxoanions binding to the active sites of mPGMT-deta was analyzed using density functional theory (DFT). The calculations indicated that the formation of MoO42−//hedetaH22+ adduct is electrostatically favored at pH 6, while the inclusion of solvation effects makes the formation of ReO4−//hedetaH22+ adduct thermodynamically more favorable. Solvation played a dominant role in determining the selectivity of oxoanion sorption to the nanocomposite. The adsorption isotherm, kinetics, and thermodynamics of Re(VII) onto mPGMT-deta were determined. The equilibrium data were best-fitted using the Langmuir adsorption model (R2 = 0.999), with a maximum sorption capacity for Re(VII) of 0.43 mmol/g. The uptake kinetics of the sorption process obeyed the pseudo-second-order model, with the influence of diffusion and external mass transfer. Based on the thermodynamic parameters, Re(VII) sorption was spontaneous and endothermic
Graphitic Carbon Nitride Modified with Aromatic Compounds for Enhanced Photocatalytic Cr(VI) Reduction
No full textHexavalent chromium (Cr(VI)) has been identified as a prevalent contaminant in wastewater
due to its extensive utilization in various industrial sectors. Photocatalytic technology helps
clean wastewater that contains Cr(VI) by changing it into less toxic Cr(III). Traditional
photocatalytic materials typically contain metal ions, and these ions may be released into water
during the photocatalytic treatment of wastewater, resulting in secondary pollution. Graphitic
carbon-nitride (g-C3N4) is a metal-free photocatalyst activated by visible light, which possesses
many promising properties. However, this material faces the high recombination rate of the
photogenerated electron-hole pairs. The unique π-conjugated electronic structure of this
material is favourable for its hybridization with the aromatic compounds, which enhances the
delocalization of the π-electron system in g-C3N4 to promote the separation of photogenerated
charges. In this work, the possibility of increasing the photocatalytic efficiency of g-C3N4 by
extending the π-conjugated system for the removal of Cr(VI) from water, was investigated.
Facile thermal copolymerization between urea and 1,5-dihydroxynaphthalene and 2-amino-5-
nitrothiazole with varying concentrations was conducted to obtain modified photocatalysts.
The photocatalysts were characterized by FE-SEM, EDS, XRD, DRS, and FTIR. The
photocatalytic reduction of Cr(VI) was investigated under simulated solar irradiation, at pH 3,
with citric acid as a hole scavenger. Photocatalytic efficiency was slightly improved in all cases,
regardless of the different aromatic structures and concentrations, indicating poor
incorporation of the aromatic moiety in the structure, which is confirmed by the methods of
characterization
Numerical analysis of tensile behaviour of Ti-13Nb-13Zr alloy after anodic oxidation
No full textThe surface of coarse-grained Ti-13Nb-13Zr (CG TNZ) alloy was modified using the anodic oxidation. In order to obtained
nanostructured oxide layer, as electrolyte in surface modification process 1M H3PO4 + NaF was used, while anodizing time was
90 minutes. The modified surface morphology was analyzed using the field emission scanning electron microscopy (FE-SEM)).
It was realized that anodic oxidation led to the creation of the oxide layer consisted of nanotubes. Tensile characteristics of the
CG TNZ alloy, before and after anodic oxidation, were determined by tensile testing. Tensile testing was performed using Micro
Tensile Specimens (MTS) with a rectangular cross-section. The anodic oxidation led to a decrease of tensile characteristics of the
CG TNZ alloy. In order to better understand tensile behaviour of the CG TNZ alloy after anodic oxidation, numerical analysis
was done. The 3D numerical model of MTS, which simulated the tensile test, was made in Abaqus software package. Numerical
results were obtained using the complete Gurson model (CGM), which is micromechanical model used for the ductile fracture of
metallic materials. The parameter that quantifies the damage in the material, that is, the volume fraction of voids or porosity, is
varied. So the value of the damage parameter, the initial void volume fraction, f0, was 0.01 and 0.005. In addition to the
elongation of the MTS, the reduction of the cross-sectional thickness at the neck of MTS was also considered. Results showed
that CGM for the initial value of the damage parameter 0.005 predicts the failure of the MTS at the corresponding value of
thickness reduction
Evaluation of Surface Properties in Biosilica-Reinforced Biobased Polyester Nanocomposites
No full textThis study investigates the surface properties of bio-based unsaturated polyester resin (b-UPR) nanocomposites reinforced with biosilica nanoparticles derived from rice husk. The b-UPR matrix was synthesized from recycled polyethylene terephthalate (PET) and renewable monomers, providing a sustainable alternative to conventional polyester resins. Unmodified and modified biosilica particles with silanes: (3-trimethoxysilylpropyl methacrylate—MEMO, trimethoxyvinylsilane—VYNIL, and 3-aminopropyltrimethoxysilane with biodiesel—AMBD) were incorporated in different amounts to evaluate their influence on the wettability, topography, and viscoelastic behavior of the composites. Contact angle measurements revealed that the addition of modified biosilica significantly improved the hydrophobicity of the b-UPR surface. The greatest increase in the wetting angle, amounting to 79.9% compared to composites with unmodified silica, was observed in the composites containing 5 wt.% SiO2-AMBD. Atomic force microscopy (AFM) analysis indicated enhanced surface roughness and uniform dispersion of the nanoparticles. For the composite containing 1 wt.% of silica particles, the surface roughness increased by 25.5% with the AMBD modification and by 84.2% with the MEMO modification, compared to the unmodified system. Creep testing demonstrated that the reinforced nanocomposites exhibited improved dimensional stability under sustained load compared to the neat resin. These findings confirm that the integration of surface-modified biosilica not only enhances the mechanical properties but also optimizes the surface characteristics of bio-based polyester composites, broadening their potential for high-performance and sustainable applications
Quantification of Phenols, Flavonoids, and Sugars in Two Medicinal Fungi: Fomes fomentarius (L.) and Schizophyllum commune (Fr.)
No full textThis study focuses on the chemical analysis of bioactive constituents in the fungi Fomes fomentarius (L.) and Schizophyllum commune (Fr.), with the aim of identifying and quantifying phenolic compounds, flavonoids, and total sugars as metabolites of significance in medicinal chemistry. Phenols and flavonoids are key factors in cellular protection against oxidative stress, which is crucial for the prevention and therapy of cardiovascular diseases, neurodegenerative disorders, and inflammatory conditions. Furthermore, the presence of sugars (polysaccharides, particularly β-glucans) additionally indicates the immunomodulatory and antitumor effects of these fungi. These chemical components act synergistically in protecting the organism from oxidative and inflammatory damage, thereby confirming their medicinal role in traditional medicine and modern therapies. In this research, fungal extracts were analysed using spectrophotometric methods to determine total phenols and flavonoids (Folin-Ciocalteu for phenols, AlCl₃ and quercetin procedure for flavonoids), as well as the phenol-sulfuric procedure for identifying the presence of sugars (polysaccharides). The analysis confirmed that both fungi contain significant amounts of phenols and flavonoids, demonstrating their potential application in the development of natural drugs and dietary supplements. Future research will focus on the identification of specific molecules of the bioactive components of these fungal species, providing a basis for further research in the field of medicinal chemistry and the pharmaceutical industry
Valorization of Yarrow (Achillea millefolium L.) Processing Waste by Fermentation: Process Optimization for the Enhancement of Biological Activity
No full textPurpose
This study aimed to optimize the fermentation of waste yarrow (Achillea millefolium L.) powder using Lacticaseibacillus rhamnosus A71 and Saccharomyces boulardii to enhance total polyphenol content (TPC) and improve key biological activities, including antioxidant, antimicrobial, and acetylcholinesterase inhibitory effects.
Methods
Fermentation was conducted using L. rhamnosus A71 and S. boulardii, with response surface methodology employed to determine optimal fermentation parameters: fermentation time, inoculum concentration, nutrient broth concentration, and liquid-to-solid ratio. The extracts were analyzed for TPC, antioxidant activity (radical scavenging and reducing power), antimicrobial activity, acetylcholinesterase inhibition, and polyphenolic profile using HPLC.
Results
A single day of fermentation with L. rhamnosus A71 increased TPC by 44%, enhanced radical scavenging activity by 11%, and improved reducing power by 42%. Two-day fermentation with S. boulardii led to a 25% increase in TPC with moderate enhancements in antioxidant capacity. Antimicrobial activity was significantly enhanced, notably with Staphylococcus aureus MIC values reduced up to 16-fold, while acetylcholinesterase inhibition was enhanced, indicating an overall improvement in the functional bioactivity of the extract. Fermentation altered the extract’s phytochemical profile: apigenin 7-O-glucoside remained dominant in the unfermented and S. boulardii-fermented samples, whereas quercetin became the most abundant compound following fermentation with L. rhamnosus A71. Levels of caffeic acid, cyanidin chloride, and quercetin increased across both fermented extracts, while rutin content decreased.
Conclusion
Microbial fermentation substantially enhanced the bioactive potential of yarrow waste extracts, improving polyphenol yield and modifying phytochemical composition in a functionally beneficial way. These findings highlight the potential of fermentation as a green biotechnological tool for converting plant-based waste materials into high-value ingredients suitable for use in nutraceuticals, functional foods, and pharmaceutical applications.This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: [https://doi.org/10.1007/s12649-025-03335-8]This is the peer-reviewed version of the following article: Milutinović, M., Banjanac, K., Nastasijević, B. et al. Valorization of Yarrow (Achillea millefolium L.) Processing Waste by Fermentation: Process Optimization for the Enhancement of Biological Activity. in Waste Biomass Valor (2025). [https://doi.org/10.1007/s12649-025-03335-8
Boosting Electrochemical Performance of Carbon Felt via Green Activation for Hybrid Energy Systems
No full textA sustainable and cost-efficient method was employed to activate and functionalizepristine carbon felt by immersing it in a commercially available 5 wt% sodium hypochlorite solution. Electrochemical characterizations, including cyclic voltammetry, galvanostatic charge–discharge analysis, capacitance, and impedance measurements, demonstrated a remarkable enhancement in performance, with the treated material exhibiting a twenty-fold increase in electrochemical activity relative to the untreated carbon felt. Morphological and physicochemical changes were confirmed through scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), water uptake studies, and contact angle analysis. To evaluate the impact of surface functionalization, polypyrrole (PPy) was electrodeposited on both treated and untreated carbon felt, revealing a fourfold increase in capacitance for the activated substrate. Building on these findings, a composite cathode material was developed by integrating functionalized carbon felt, polypyrrole, and silver chloride (AgCl) via a modified successive ion layer adsorption and reaction (SILAR) process. Assembled into a quasi-rechargeable hybrid cell using an AZ63 magnesium alloy anode and seawater as the electrolyte, the system demonstrated excellent electrochemical behavior. The cell delivered high specific power at fast discharge rates and notable energy capacity under slower regimes, where oxygen reduction played a dominant role. These results highlight the potential of such hybrid systems for use in marine emergency applications and temporary power supply units for shallow seawater monitoring. The combination of renewable electrolytes and environmentally benign components positions this technology as a promising route for sustainable energy storage
UV Irradiation’s Influence on Fumitory Extract-Loaded Liposomes
No full textThe aim of the present study was the characterization of fumitory extract-loaded liposomal vesicles after UV irradiation via the determination of the encapsulation efficiency, size, polydispersity index (PDI), zeta potential, mobility, and conductivity. The encapsulation efficiency was the same before and after UV irradiation (>69%). The particle size and PDI of the UV-irradiated liposomes with the fumitory extract were 294.2 ± 4.1 nm and 0.387 ± 0.011, respectively. The zeta potential after UV irradiation was −5.51 ± 0.4 mV. The mobility and conductivity of the obtained liposomal particles were −0.429 ± 0.012 µmcm/Vs and 0.468 ± 0.005 mS/cm, respectively. The results indicate the existence of nanoparticles and a non-uniform system, while a negative zeta potential value is related to the organization of phospholipids. Since UV irradiation did not cause significant changes in all of the mentioned parameters of the fumitory extract-loaded liposomes, it can be employed as a sterilization step in the preparation of liposomes.The IX International Congress “Engineering, Environment and Materials in Process Industry”—EEM2025, 2-4 April 2025, Bijeljina, Bosnia and Herzegovin
Imobilizacija alkalaze na hitozan/glutaraldehid/tripolifosfat perle dobijene tehnikom inverzne emulzije
No full textEnzymes immobilization can efficiently solve limitations of their large-scale
application, such as stability and reusability. In this study, Alcalase
® 2.4L
(protease from Bacillus licheniformis) was covalently immobilized onto
chitosan beads obtained by inverse emulsion technique using 1.5% (m/v) of
chitosan and 0.67% (v/v) or 1.0% (v/v) of glutaraldehyde (CTPP (1.5/0.67)
and CTPP (1.5/1.0)). Afterward, the beads were additionally crosslinked by
immersion into 10 % (m/v) tripolyphosphate solution. The parameters
studied were enzyme loading, enzyme coupling yield, bead diameter, SEM,
biocatalyst activity, and FTIR. The beads had adequate enzyme loading and
enzyme coupling yield (Pgmax was 117.1 mg/g dry CTPP 1.5/0.67 and 90.1
mg/g dry CTPP 1.5/1.0, and μmax was 96.7% for both carriers). CTPP
(1.5/1.00) beads were smaller (diameter 635.2 ±25.2 mm wet/
230.4±12.5 mm dry beads) and showed a higher specific activity of
20.1 ± 0.23 IU/mgprotein. The immobilized Alcalase® 2.4L was tested for
hydrolyzing egg white and soy proteins. Alcalase® 2.4L, covalently attached
to CTTP (1.5/1.0) chitosan beads, is a promising choice for industrial
processes involving egg white protein hydrolysis, as the enzyme achieved
a notable hydrolysis rate of 26.34 ± 0.879% after 195 minutes. Additionally,
it remained effective hrough five successive applications under practical
conditions (50 °C, pH 8).Imobilizacija enzima može efikasno da reši ograničenja njihove široke primene, kao što
su stabilnost i ponovna upotreba. U ovom radu je enzim Alcalase® 2.4L (proteaza
Bacillus licheniformis) kovalentno imobilisan na perle hitozana dobijena tehnikom
inverzne emulzije korišćenjem 1,5% (m/v) hitozana i 0,67% (v/v) ili 1,0% (v/v) )
glutaraldehida (CTPP (1,5/0,67) i CTPP (1,5/1,0)). Nakon toga, perle su dodatno
umrežene uranjanjem u 10% (m/v) rastvor tripolifosfata. Proučavani su opterećenje
enzima, prinos enzimskog kuplovanja, prečnik perli, SEM, aktivnost biokatalizatora i
FTIR. Perle su imale adekvatno punjenje enzima i prinos enzimskog kuplovanja (Pgmax je
bio 117,1 mg/g suvog CTPP 1,5/0,67 i 90,1 mg/g suvog CTPP 1,5/1,0, a μmax je bio 96,7%
za oba nosača). CTPP (1,5/1,00) perle su bile manje (prečnik 635,2 ±25,2 mm
vlažne/230,4±12,5 mm suve perle) i pokazale su veću specifičnu aktivnost od 20,1 ± 0,23
IU/mg proteina. Imobilisani enzim Alcalase® 2.4L je testiran na hidrolizu proteina
belanaca i soje. Enzim Alcalase® 2,4L, kovalentno vezan za CTTP (1,5/1,0) hitozan
perle, je obećavajući izbor za industrijske procese koji uključuju hidrolizu proteina
belanaca, pošto je enzim postigao značajan stepen hidrolize od 26,34 ± 0,879% posle
195 minuta. Pored toga, ostao je efikasan kroz pet uzastopnih primena u praktičnim
uslovima (50 °C, pH 8)