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Determination of selected antibiotics in hospital and urban wastewater using liquid chromatography-tandem mass spectrometry
No full textHospital wastewater is one of the primary sources of antibiotics in the environment, as these drugs are widely used to treat and prevent infections in hospitals. Trace levels of antibiotics in surface waters and sediments pose a major threat to human health and ecosystems due to the potential
for causing the microbial resistance. The issue is particularly concerning in the Serbian capital, Belgrade, lacking the facilities for the treatment of urban and hospital wastewater. The objective of
this study was the development and optimization of liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of four selected antibiotics (sulfamethoxazole, trimethoprim, ceftriaxone, and azithromycin) in hospital and urban wastewater
samples. In the sample preparation procedure, the sample pH was optimized, using Oasis HLB
cartridges for the solid-phase extraction and methanol as the extraction solvent. Using the developed method, all four antibiotics were found in three hospital and three urban wastewater samples from Belgrade. The only exception was ceftriaxone, which was detected only in hospital wastewater at the highest concentrations of all antibiotics detected (up to 1016 ng L–1). The results revealed generally higher antibiotic levels in hospital wastewater, with azithromycin levels up to ten times higher than in urban wastewater
Ni-Based Coatings on Molybdenum: Influence of Current Density and Basalt on Mechanical Properties and Forensic Relevance
No full textNi and Ni/basalt (Ni/Bst) coatings prepared by the electrodeposition on Mo substrate were analyzed with the aim of their potential application in forensics. The coatings of Ni and Ni/Bst are produced galvanostatically from the sulfamate electrolyte at different current densities and characterized by scanning electron microscope (morphology), X-ray diffraction (structure) and Vickers microindentation (microhardness). The wettability of Ni and Ni/Bst coatings was also investigated. While morphology and microhardness of the coatings strongly depended on the current density of electrodeposition and the presence of basalt particles in the electrolyte, the effect of basalt addition on structure of the coatings was not observed. The microhardness of Ni coatings was in the (1.6951–5.7246) GPa range, while the addition of basalt particles increased the range to (5.8206–10.7981) GPa. Both Ni and Ni/Bst coatings were hydrophilic, whereas comparison of the coatings obtained at the same current density showed that incorporation of the basalt particles in the coating decreases the degree of hydrophilicity, as observed by the increase in the water contact angle (WCA). The largest WCA, i.e., the smallest hydrophilicity, showed Ni/Bst coating produced at 30 mA cm−2 (WCA ≈ 75.5°), and was about 46.7% larger than that of Mo substrate (WCA ≈ 51.5°). This coating also showed the best development of latent fingerprints with clearly visible ridge details, indicating that there is strong correlation between fingerprint development and the wettability of the coatings
Electrochemical and Surface Insights Into X12CrMoWVNbN10-1-1 Steel Corrosion in Chloride Solutions at Variable pH
No full textThe corrosion behavior of X12CrMoWVNbN10-1-1 steel was investigated in 0.1 M NaCl solutions of different pH values (2.9, 6.5, and 10.3) using electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and potentiodynamic polarization (PDP). A pronounced pH dependence was observed, with the highest corrosion rate and lowest polarization resistance in acidic medium. Neutral and alkaline environments promoted passive film formation, with the alkaline solution providing superior protection against general and pitting corrosion. The enhanced passivation is attributed to the stabilizing role of hydroxide ions. Surface morphology by optical microscopy and SEM confirmed these trends, revealing severe degradation in acid and compact surfaces in neutral and alkaline media. Quantitative comparison with reference steels (P91 and 316 L) confirms an order-of-magnitude improvement in corrosion resistance, emphasizing the practical relevance of X12CrMoWVNbN10-1-1 for chloride-containing environments. The results highlight its strong corrosion stability under variable-pH exposure. © 2025 The Author(s). Materials and Corrosion published by Wiley-VCH GmbH
Cavitation erosion damage of pyrophyllite samples reinforced with cordierite, mullite and zirconium-silicate
No full textThis study investigates the cavitation erosion resistance of pyrophyllite-based composites reinforced with 20 wt.% of cordierite, mullite and zirconium-silicate, sintered at 1200 °C. The phase composition and microstructural features of the sintered samples were analyzed using XRD and scanning electron microscopy (SEM). Cavitation resistance was evaluated using the ultrasonic vibratory method with a stationary sample according to ASTM G32, by monitoring the mass loss and surface degradation as a function of exposure time. The results show that the addition of refractory phases with higher hardness significantly improves the cavitation resistance of pyrophyllite. Among the investigated compositions, the sample reinforced with cordierite (P+C) exhibited the lowest cavitation rate (0.145 mg/min) and minimal surface damage, attributed to its compact and homogeneous microstructure that suppresses microcrack initiation and propagation. The samples containing zirconium-silicate (P+Z) demonstrated moderate improvement, while mullite-reinforced samples (P+M) showed the least enhancement due to their elongated grain morphology facilitating brittle fracture. These findings indicate that cordierite is the most effective reinforcing phase for improving the cavitation durability of pyrophyllite-based ceramics, enabling their potential application in hydrodynamic systems exposed to cavitation-induced wear.Oвај рад истражује отпорност на кавитациону ерозију композита на бази
пирофилита ојачаних са 20 теж. % кордијерита, мулита и цирконијум-силиката,
22
синтерованих на 1200 °C. Фазни сстав и микроструктурне карактеристике синтерованих
узорака анализирани су помоћу рендгенске дифракције (XRD) и скенирајуће електронске
микроскопије (SEM). Otтпорност на кавитацију процењена је ултразвучном вибрационом
методом са стационарним узорком према ASTM G32, праћењем губитка масе и
деградације површине као функције времена излагања. Резултати показују да додавање
ватросталних фаза са већом тврдоћом значајно побољшава отпорност пирофилита на
кавитацију. Међу испитиваним саставима, узорак ојачан кордијеритом (P+C) показао је
најнижу брзину кавитације (mg/min) и минимално оштећење површине, што се приписује
његовој компактној и хомогеној микроструктури која сузбија настанак и ширење
микропукотина. Узорци који садрже цирконијум-силикат (P+Z) показали су умерено
побољшање, док су узорци ојачани мулитом (P+M) показали најмање побољшање због своје
издужене морфологије зрна која олакшава крти лом. Ови налази указују да је кордијерит
најефикаснија ојачавајућа фаза за побољшање издржљивости керамике на бази
пирофилита на кавитацију, што омогућава њихову потенцијалну примену у
хидродинамичким системима изложеним хабању изазваном кавитацијом
Innovative Wound Healing Utilizing Bioactive Fabrics Functionalized with Tormentillae rhizoma Extract: An In Vivo Study on Wistar Albino Rats
No full textThis paper presents an innovative protocol for fabric functionalization using Tormentillae
rhizoma extract, the chemical composition of which was proved via LC/MS analysis. The
extract demonstrated antioxidant activity > 99%, and antibacterial efficacy against E. coli
and S. aureus > 99%. Cotton, wool, polyamide, and cellulose acetate were functionalized
with the prepared extract, all showing > 90% antioxidant activity. Functionalized cotton,
wool, and polyamide exhibited > 99% antibacterial activity against both bacteria. Based
on these findings and the fabrics’ ability to release bioactive compounds, functionalized
cotton and polyamide fabrics having excellent bioactivity but a lower ability to release
bioactive compounds can serve as protective fabrics for people with sensitive skin prone
to wounds, and various products for hospitals. Functionalized wool was identified as the
most suitable wound dressing for in vivo preclinical investigation on Wistar albino rats. The
obtained results showcased a wound-healing rate of 95.54%, and hydroxyproline content
of 8.08 µg/mg dry tissue for rats treated with functionalized wool. Compared to negative,
positive, and a group of rats treated with non-functionalized wool, those treated with functionalized wool demonstrated elevated values of tissue redox state parameters, superoxide
dismutase (SOD) and catalase (CAT), and a notable reduction in thiobarbituric acid reactive
substances (TBARS) value. Analysis of the blood samples of rats treated with functionalized
wool indicated increased levels of antioxidant defense system parameters (SOD and CAT)
and decreased pro-oxidative markers superoxide (O2
−) and TBARS. Further clinical trials
are needed to validate these findings
Copper-Mediated Leaching of LiCoO2 in H3PO4: Kinetics and Residue Transformation
No full textThe recycling of spent lithium-ion batteries (LIBs) requires efficient and sustainable methods
for recovering critical metals. In this study, the leaching behavior of LiCoO2 cathode
material obtained from spent LIBs was investigated in phosphoric acid, using copper
powder recovered from waste LIBs as a reducing agent. Leaching experiments were
conducted under various conditions (temperature, solid-to-liquid ratio, agitation rate) and
compared with systems without copper. In the absence of copper, lithium and cobalt,
recoveries after 30 min were approximately 77% and 23%, respectively. The addition of
copper significantly enhanced leaching, achieving >96% recovery for both metals at 80 ◦C,
with most extraction occurring within the first 30 min. Kinetic analysis using the shrinking
core model indicated a mixed-control mechanism involving both surface chemical reaction
and product layer diffusion. The calculated activation energies were 20.2 kJ·mol−1
for
lithium and 16.1 kJ·mol−1
for cobalt. Solid residues were characterized by X-ray diffraction
(XRD) and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS).
XRD results revealed that the composition of the residues varied with leaching temperature:
Co3O4 was consistently detected, whereas Cu8(PO3OH)2(PO4)4·7H2O appeared only when
leaching was performed above 50 ◦C. Thermodynamic calculations supported the reductive
role of copper and provided insight into possible reaction pathways. These findings
confirm the effectiveness of copper-mediated leaching in phosphoric acid and demonstrate
that temperature strongly influences residue phase evolution, thereby offering valuable
guidance for the design of sustainable LIB recycling processes
Starch-Gelatin-Based Scaffolds for Cartilage Defect Repair: An in vitro Study Supporting Its Potential Clinical Use
No full textObjective: The aim was to investigate starch-gelatin hydrogels as scaffolds for chondrogenesis and compare these with other materials currently in use regarding cell retention and growth. Methods: Two variants of starch-gelatin-scaffolds and one chitosan-based scaffold were fabricated by casting and freeze-drying. The resulting materials were analyzed with respect to physicochemical and mechanical properties, cut to size, and seeded with human articular chondrocytes. Cell retention and proliferation were evaluated at 1, 14, and 42 days of culturing. Extracellular matrix production was analyzed by histo- and immunohistochemistry. Comparisons were made with that of commercially available hyaluronan- (Hyalofast®) and collagen-based (ChondroGide®) scaffolds, and synthesized chitosan hydrogels. Results: The starch-gelatin materials exhibited highly porous structures stabilized by hydrogen bonding, with swelling behavior similar to native cartilage and favorable mechanical handling properties. Despite differences in initial cell retention, all materials except chitosan supported robust cell growth, reaching similar levels after 14 days. No significant changes were observed between 14 and 42 days with the exception of Hyalofast® showing decreased cell number. Chitosan-supported cell growth was more linear over the culture period, but resulted in only half the cell number by day 42 compared with the other materials. Without cells, Hyalofast and one variant of the starch/gelatin hydrogel degraded before day 42. starch/gelatin scaffolds showed collagen I, II, and aggrecan deposition. Conclusion: Starch-gelatin scaffolds displayed favorable mechanical properties, supported cell growth comparable to commercial scaffolds, and promoted deposition of cartilage-specific extracellular matrix, highlighting their chondrogenic potentia
Postupak za imobilizaciju enzima na oksidovanim ljuskama krompira
No full textPredmetnim pronalaskom opisan je postupak
imobilizacije enzima, peroksidaze, na ljuskama
krompira kao otpadnom materijalu i korišćenje tako
imobilisane peroksidaze u razgradnji tekstilne boje.
Ljuske krompira kao otpadni materijal se -
jednostavnom modifikacijom prevode u nosač za
imobilizaciju peroksidaze iz rena. Nosač je
ekonomski isplativ i u skladu sa konceptom „nula
otpada“. Takođe, iskorišćenje otpada kao sirovina
za druge procese smanjuje emisiju gasova sa
efektom staklene bašte. Oksidacijom krompirovih
ljuski postiže se njihova aktivacija tako što se
poveća sadržaj aldehidnih grupa, za koji se
kovalentno vezuje peroksidaza iz rena. Imobilisana
peroksidaza iz rena na oksidovanim krompirovim
ljuskama može da se koristi za razgradnju boje koje
se koriste u tekstilnoj industriji.Broj prijave: P-2023/1067Broj i datum rešenja o priznanju prava: 2025/10633 24.12.2025Glasnik intelektualne svojine broj 05/2025, dana 30.05.2025
Synthesis, antimicrobial, anticancer activity, 3D QSAR, ADMET properties, and in silico target fishing of novel N,N-disubstituted chloroacetamides
No full textThe recent FDA approval of afatanib, ibrutinib, and osimertinib, which covalently bind to specific cysteine residues in target kinases, has renewed interest in covalent drug discovery. Besides α,β-unsaturated carbonyls, chloroacetamides have emerged as popular warheads for designing targeted covalent inhibitors. In this study, we synthesized thirteen N,N-disubstituted chloroacetamides (1–13) by acylating secondary amines with chloroacetyl chloride, selecting substituents to provide a wide range of lipophilicity. We evaluated their anticancer and antimicrobial activity, finding five compounds with significant cytotoxicity against HeLa, K562, and A549 cell lines (IC50 <10 μM). Notably, compound 10 activated caspases 3, 8, and 9, promoting both intrinsic and extrinsic apoptotic pathways, while compounds 9–12 were strong apoptosis inducers. A 3D QSAR model showed that aromatic substituents on nitrogen atoms reduced HeLa potency, whereas the overall molecular shape had a positive effect. ChemBL and pharmacophoric similarity searches suggested potential anticancer targets, including alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), glycogen synthase kinase-3β, and calmodulin. Docking studies indicated that chloroacetamides bind to ADH and ALDH via hydrogen bonds and hydrophobic interactions. Pharmacokinetics predictions suggest that chloroacetamides are druglike molecules with promising ADMET properties
Investigating the Effect of Enzymatically-Derived Blackcurrant Extract on Skin Staphylococci Using an In Vitro Human Stratum Corneum Model
No full textBackground/Objectives: Numerous intrinsic and extrinsic stressors can disrupt the balance of the skin microbiome, leading to the development of various skin diseases. It has been proven that coagulase-negative staphylococci (CoNS) are important commensals for maintaining skin microbiome homeostasis and fighting cutaneous pathogens such as Staphylococcus aureus (S. aureus). Here, we examined the influence of polyphenol-rich enzymatic blackcurrant extract (EBCE) on pathogenic coagulase-positive S. aureus strains and beneficial CoNS, like Staphylococcus epidermidis (S. epidermidis), to explore its potential for rebalancing the skin microbiota. Methods: The polyphenol profile of EBCE was determined by ultra-high-pressure liquid chromatography–tandem mass spectrometry. Microwell plate assays were employed to study the effect of EBCE on five S. aureus strains isolated from the skin of atopic dermatitis patients. An in vitro human stratum corneum model was used to test its effect on mixed bacterial cultures. Results: EBCE inhibited the growth of all tested S. aureus strains by 80–100% at the highest tested concentration after 7 h. No microbial growth was observed at the highest tested EBCE concentration using the stratum corneum model inoculated with one selected pathogen (S. aureus SA-DUS-017) and one commensal laboratory strain (S. epidermidis DSM 20044). The lowest tested concentration did not interfere with S. aureus growth but strongly stimulated the growth of S. epidermidis (~300-fold colony forming unit increase). In addition, low EBCE concentrations strongly stimulated CoNS growth in microbiome samples taken from the armpits of healthy volunteers that were spiked with S. aureus SA-DUS-017. Conclusions: These preclinical data support further testing of EBCE-enriched topical preparations as potential cutaneous prebiotics in human studies