Abstract:

Background/Objectives: The stability of pharmaceutical compounds is a critical quality attribute; it is an essential step in the drug development process. Significant focus is required to understand the variation of quality pharmaceutical compounds under prevailing environmental storage conditions. Simultaneously, many issues arise in understanding updated regulations, knowledge of data sciences, and appreciation of common practices, presenting a challenge for defining a retest period and in predicting a prolongation of the shelf life of drug products. The purpose of this paper is to conduct a statistical study to assess stability and to forecast a prolongation of drugs shelf-life. Methods: A case study is suggested to identify the most appropriate statistical test for assessing stability. The results of physical and chemical tests are considered to detect changes and variability during different conditions (accelerate, intermediate and real). Results: In the stability study, minimal variability in the content of the substance of interest was obtained using the predictive interval approach over a period of 31 months, and an interval of ±1,2%. Conclusion: The example of the statistical study is given to provide different perspectives on statistical approaches for market approval.

Abstract: The vibrational properties of the chiral sulfoxide methyl-p-tolyl-sulfoxide (Metoso) were investigated by infrared and Raman spectroscopy in the solid, liquid and aqueous solution phases, for both the enantiopure compounds and their racemic mixture. Experimental data were complemented by DFT calculations on the isolated enantiomer and on the two RR and RS dimeric conformers to support spectral interpretation and mode assignment. The IR and Raman spectra of the crystalline enantiomer and racemic mixture are similar, indicating comparable molecular organization and intermolecular interactions in the solid state. Upon melting, band broadening and frequency shifts are observed, consistent with molecular disorder and the breaking of weak intramolecular interactions, accompanied by changes in the S–O and S–CH₃ and C-H stretching frequencies. In aqueous solution, further broadening and opposite shifts of these bands reflect the formation of Metoso–H₂O complexes through hydrogen bonds. Theoretical spectra reproduce the observed trends and confirm that either solvent or phase transitions control the balance between intra- and intermolecular interactions thus influencing the vibrational degrees of freedom of the model chiral sulfoxide.

Abstract: A deterministic platform for engineering epitaxial strain in CaMnO3 (CMO) thermoelectric thin films is demonstrated using pulsed laser deposition, enabling precise control of the interplay between strain state and oxygen-vacancy formation. High-quality epitaxial CMO films are grown on four different single-crystalline substrates, which impose fully relaxed, partially relaxed, low-tensile, and high-tensile strain states, respectively. Increasing tensile strain induces a monotonic expansion of the unit-cell volume and a systematic rise in oxygen vacancy concentration. Oxygen vacancies increase carrier concentration but decrease mobility due to enhanced scattering. Reducing tensile strain suppresses vacancy scattering and increases both electrical conductivity (σ) and the Seebeck coefficient (S), mitigating the conventional inverse relationship between S and σ. Fully relaxed films exhibit σ approximately four orders of magnitude higher at room temperature than highly tensile-strained films. These relaxed films also show the highest power factor (PF = S2・σ), exceeding strained films by up to six orders of magnitude. Strain-controlled oxygen vacancies thus provide a direct route to optimize charge transport and maximize the thermoelectric performance of CMO thin films.

Abstract: Platinum-based drugs play a pivotal role in contemporary cancer treatment, but their therapeutic utility is often limited by acquired resistance. The diiodido analogue, cis-PtI2(NH3)2 is a promising derivative that has demonstrated the ability to overcome cis-platin resistance in vitro. To establish the molecular basis for this superior activity, we in-tegrated experimental 14N Nuclear Magnetic Resonance (NMR) spectroscopy with com-putational density functional theory (DFT) methods to precisely and comparatively un-derstand the drug activation mechanisms. Comparative 14N NMR experiments elucidated the initial ligand substitution step, confirming halide displacement and a markedly high-er tendency for ammonia release from cis-PtI2(NH3)2, particularly when reacting with sul-fur-containing amino acids. Complementary DFT calculations determined the substitu-tion energy values, revealing that the superior leaving-group ability of iodide results in a thermodynamically more favorable activation. Conceptual DFT parameters (softness, hardness, and Fukui indices) further demonstrated that initial substitution induces a strong trans effect, leading to the electronic sensitization of the remaining iodide ligand. This strong agreement between computational predictions and experimental data estab-lishes a coherent molecular activation mechanism for cis-PtI2(NH3)2 demonstrating that iodide substitution promotes both thermodynamic and electronic activation of the plati-num center, which is the key to its distinct pharmacological profile and ability to circum-vent resistance.

Abstract: Textiles can host microorganisms making antimicrobial function an essential safety feature. An ideal antimicrobial agent is non-nontoxic, stable, and durable. This study explores a core-shell nanofiber with core of cationic biopolymer ε-poly-L-lysine (PL) and shell of structurally similar and biocompatible polyamide-6 (PA). The core-shell structure is expected to have stable antimicrobial function than its monolithic counterpart. Further, thermal crosslinking is expected to prevent rapid diffusion of the water-soluble PL. Therefore, this study establishes a comparison between a monolithic (Control), a core-shell (CS), and thermally crosslinked core-shell (CL-CS) nanofiber of PL and PA. Morphological analysis confirmed the successful generation of the core-shell nanofibers. The samples exhibited hydrophilic behavior that is desirable in various functional textiles. All the samples exhibited antimicrobial function. Unlike control, CS and CL-CS showed no significant difference between the antimicrobial activity after 24 hours and 21 days of bacterial incubation. Therefore, the core-shell structure allowed sustainable and durable antimicrobial action. Lastly, CL-CS sample exhibited reusable antimicrobial function owing to the core-shell structure paired with thermal crosslinking. This study showcases a fiber system with non-toxic, durable, and reusable antimicrobial function. This study builds grounds for the development and multifaceted holistic characterization of safe, stable, and scalable antimicrobial textiles.

Abstract:

Oxytocin (OXT) has demonstrated potential therapeutic effects in Alzheimer’s disease (AD) through mechanisms such as reducing amyloid-β (Aβ) accumulation and tau deposition, as well as exerting antioxidant and anti-inflammatory properties. A recent study further revealed that OXT can decrease acetylcholinesterase (AChE) activity in liver and kidney tissues, suggesting that its effects on Aβ and tau pathology may be mediated, at least in part, through AChE inhibition. Based on this rationale, a series of OXT derivatives were designed, synthesized, and evaluated using protein-protein interaction analysis, molecular docking, in vitro AChE inhibition assays, enzyme kinetics, and antioxidant assays. Docking and protein-protein interaction studies showed that OXT and its analogues fit well within the 20 Å gorge of the AChE active site, engaging both the catalytic active site (CAS) and the peripheral anionic site (PAS). In vitro AChE inhibition assays revealed promising activity, with OXT (Cmpd.16) and analogue 7 (Cmpd.7) exhibiting IC₅₀ values of 8.5 µM and 3.6 µM, respectively. Kinetic analysis determined inhibition constants (Kᵢ) of 45 µM for Cmpd.16 and 6 µM for Cmpd.7, with both compounds following a mixed-type inhibition mechanism. Furthermore, antioxidant evaluations indicated potential neuroprotective properties. In conclusion, OXT analogues act as dual-binding site AChE inhibitors, as supported by docking, protein-protein interaction, and kinetic analyses, and display greater inhibitory activity than OXT itself. These findings suggest that OXT analogues represent promising candidates for further development as AChE inhibitors for AD therapy.

Abstract: The development of non-noble metal catalysts provides a cost-effective and sustainable route for glucose oxidation to gluconic acid. In this study, a series of catalysts based on inexpensive transition metals (Cr, Cu, Ni, Fe) and/or Au were synthesized using siliceous supports (SiO₂ and MCM-41) and systematically evaluated. The aim was to partially or fully replace noble metals with lower-cost alternatives, while maintaining high catalytic performance. Comprehensive characterization—including ICP-AES for composition, N₂ adsorption–desorption for porosity, XRD for structure, H₂-TPR for reducibility, and NH₃-TPD for acidity—was conducted to establish structure–property relationships. Among the tested catalysts, Ni- and Fe-based systems exhibited superior stability, with NiO/SiO₂ achieving gluconic acid yields comparable to Au. The bimetallic Au–Ni/SiO₂ catalyst displayed enhanced metal–support interactions and minimal leaching (< 2 %), while Au–Fe/SiO₂ improved selectivity, yielding up to 23 % gluconic acid, surpassing 5Fe/SiO₂ (18 %) and 0.3Au/SiO₂ (15 %), albeit with lower stability. These results highlight the potential of low-cost transition-metal and bimetallic catalysts as efficient and eco-nomically viable systems for selective glucose oxidation, providing insights for rational catalyst design in sustainable carbohydrate valorization.

Abstract: A series of azido- and cyclooctyne-functionalized N-hydroxysuccinimidyl esters (NHS esters) and benzotriazolides were prepared and used as N-acylation reagents to obtain azido- (BSA-1) and cyclooctyne-functionalized bovine serum albumin proteins (BSA-2), fluorescein derivatives 5 and 6, and homobifunctional linkers 3 and 4. Strain-promoted azide-alkyne cycloaddition (SPAAC) and copper-catalyzed azide-alkyne cycloaddition (CuAAC) of azido- functionalized fluorescent probe 5 and alkyne- functionalized fluorescent probe 6 with complementary functionalized proteins BSA-2 and BSA-1 yielded fluorescent cycloadducts BSA-2-5 and BSA-1-6. These cycloadducts were used to determine the loading of BSA-1 and BSA-2 with the respective azido and cyclooctyne groups based on their molar absorbances and fluorescence intensities. Dimerization through covalent cross-linking of BSA was then performed by SPAAC between azido-functionalized BSA-1 and cyclooctyne-functionalized BSA-2, and by treating BSA-1 and BSA-2 with 0.5 equiv. of com-plementary bis-cyclooctyne linker 4 and bis-azide linker 3. Although the formation of covalent dimers BSA-1-2-BSA, BSA-1-6-1-BSA, and BSA-2-5-2-BSA was detected by SDS-PAGE analysis, this was a minor process, and most of the functionalized BSA did not form covalent dimers.

Abstract: This research investigates the potential of secondary lavender biomass (Lavandula officinalis) as a raw material for paper production within the context of the circular economy and its practical applications. Lavender stems, a by-product of essential oil extraction, were processed using the nitrate-alkali pulping method. The chemical composition of the raw material was analysed according to TAPPI standards, and the resulting pulp was characterised in terms of its mechanical and physical properties, including tensile strength and air permeability. Lavender stems contained 29.43% cellulose and 24.10% lignin, indicating moderate delignification efficiency. The pulp yield was 24.2% with a Kappa number of 15.9. Of the prepared sheets, the paper with a weight of 80 g·m⁻² showed the best mechanical properties, with a breaking length of 1.71 km and a tensile strength index of 16.76 N·m·g⁻¹.In addition, lavender-based paper demonstrated a repellent effect against textile moths (Tineola bisselliella), reducing insect activity by approximately 70% compared to control samples. This bioactivity is attributed to residual volatile compounds such as linalool and linalyl-acetate. Overall, lavender secondary biomass represents a promising non-wood fibre for the production of bio-degradable, functional paper materials that combine structural integrity with natural repellent properties.

Abstract: Due to their chemical structure and convenient, tunable physicochemical properties, intermetallic alloys and materials are promising for use in various fields, such as gas sensors. The aim of this study was to perform DFT GGA calculations of the adsorption energy of atomic nitrogen and the properties of partially substituted metal atoms with nitrogen in Ti3Sb supercells with an A15 cubic structure. Adsorption and doping at various adsorption sites and crystallographic orientations (110; 111; 100), as well as their electronic properties, were studied in 2 × 2, 3 × 3, and 5 × 5 supercells. The density of states (DOS) of Ti3Sb–N supercells with two different positions of partial substitution of nitrogen for Ti3Sb metal atoms was calculated: N/Ti and N/Sb. Comparative data show that the structural and energetic properties of Ti3Sb–N vary compared to pure Ti3Sb. Controlled incorporation of nitrogen atoms and partial substitution of Ti3Sb atoms allow for tuning of the properties of Ti3Sb–N. These data can be used to optimize and predict the electronic structure and response characteristics of such materials for electronics and catalysis. They are also important as potential sensor materials with exceptional properties and promising applications for nitrogen detection in targeted developments.

Abstract: Aiming to obtain chemicals from renewable sources to mitigate global warming, the catalytic pyrolysis of tamarind pulp, obtained from juice industries, was studied. Catalysts based on HZSM-5 zeolite prepared from rice husk ash using ultrasound, microwaves, and a combination of both were employed. The catalysts were characterized by elemental analysis, X-ray diffraction, specific surface area and porosity measurements, scanning electron microscopy, and acidity measurements. The specific surface areas and the micropore volumes were slightly affected by the treatments, microwave alone or combined with ultrasound, having the strongest effect. The number of acid sites increased, and the relative number of strong sites decreased with the treatments. The relative amount of Bronsted to Lewis sites was increased by ultrasound and decreased by microwave, alone or combined. These catalysts decreased oxygenated products and increased BTEX production during tamarind pulp pyrolysis. The product distribution was similar for all cases, meaning that HZSM-5 with the following characteristics are selective catalysts to BTEX in tamarind pulp pyrolysis: specific surface area= 310-347 m2/g; micropore volume= 0.099-0.105 cm3/g; acidity= 327 to 571 µmol NH3/gcat and Bronsted to Lewis acid sites ratio= 0.034 to 0.044.

Abstract: Silver nanoparticles (AgNPs) are widely studied in oncological nanomedicine, although concerns persist regarding their toxicity, elimination, and tissue accumulation. The biological properties of AgNPs depend on the synthesis method and the reducing agent used, which can influence cytotoxicity and cellular metabolism. This study aimed to evaluate the effect of the reducing agent on the cytotoxicity of AgNPs in leukemia (JURKAT) cell lines and peripheral blood mononuclear cells (PBMC). AgNPs were synthesized via chemical reduction using glucose (GLU) or polyvinylpyrrolidone (PVP) as reducing agents. Nanoparticles were characterized by UV-Vis, FTIR, DLS, zeta potential, and TEM. Cell viability was assessed through trypan blue exclusion, and cytotoxicity was determined using the MTT assay. UV-Vis analysis showed distinct surface plasmon resonance profiles, and FTIR confirmed characteristic functional groups on the nanoparticle surface. DLS and zeta potential values indicated colloidal stability, with PVP-AgNPs presenting a more negative surface charge. TEM revealed greater size heterogeneity in GLU-AgNPs. GLU-AgNPs induced lower cytotoxicity and higher cell viability in JURKAT and PBMCs compared to PVP-AgNPs (p &lt; 0.05). Leukemia cells were more susceptible to both nanoparticle types than PBMCs, showing a favorable selectivity index for GLU-AgNPs (SI = 2.44). These findings suggest that biocompatible reducing agents improve AgNP safety.

Abstract: Natural products are sources of secondary metabolites with various biological activities. This review highlights the promising potential of the Annonaceae family, a large clade of flowering plants with 107 genera and over 2300 species. Known for their vast pharmacological activities, several genera and species within this family are considered excellent sources of bioactive molecules due to the diversity of their secondary metabolites. Chemical investigations have revealed the presence of alkaloids, mainly isoquinolinic alkaloids, phenolic compounds, terpenoids, lactones, and acetogenins. The Annonaceae family exhibits anti-inflammatory, insecticidal, antimicrobial, leishmanicidal, cytotoxic, antitumor, trypanocidal, antioxidant, gastroprotective, and antimalarial activities. However, most studies focus on plant extracts and essential oils, with few isolated molecules and mechanisms of action identified. Investigating the biological activity of isolated compounds is crucial for new drug discovery. This review also compiles important information for the pharmaceutical and agricultural industries.

Abstract: The reaction of a 2-naphthol-derived Mannich base with the push–pull 5-morpholinopenta-2,4-dienal under acidic conditions unexpectedly afforded (7aR*,7bR*)-7a,7b-dihydro-15H-dibenzo[f,f']cyclopenta[1,2-b:5,4-b']dichromene. The structure of this product was unambiguously confirmed by NMR spectroscopy and X-ray diffraction analysis. A plausible mechanism involves the in situ generation of 1,2-naphthoquinone-1-methide, followed by a [4 + 2] cycloaddition and a subsequent interrupted iso-Nazarov cyclization. In this process, the enol tautomer of the resulting fused cyclopentenone is trapped by a second equivalent of the 1,2-naphthoquinone-1-methide, leading to the observed polycyclic framework.

Abstract: This study investigates the influence of negative bias voltage on the plasma nitriding be-havior of 25Cr2Ni4W low-alloy steel to enhance its surface mechanical and tribological performance. The bias voltage was systematically varied from 2.0 to 3.5 kV, while dis-charge power, pressure, and treatment time were kept constant. Substrate heating was achieved through a self-induced mechanism. X-ray diffraction (XRD) analysis confirmed the formation of a compound layer consisting of ε-Fe₂₋₃N and γ′-Fe₄N phases. With in-creasing bias voltage, a progressive transformation toward the γ′-Fe₄N phase was ob-served, accompanied by a reduction in ε-Fe₂₋₃N content. This microstructural evolution significantly affected surface mechanical properties. Nanoindentation results revealed a marked increase in hardness compared with the untreated substrate. The sample treated at 2.0 kV (CW1) exhibited the highest and most stable nanohardness (≈ 6000 MPa), indi-cating a dense and coherent nitride layer. Conversely, the 3.5 kV (CW4) condition yielded a lower nanohardness (≈ 4000 MPa) due to excessive sputtering and reduced nitrogen diffusion. These results demonstrate that accurate control of negative bias voltage is a key factor in tailoring the nitride phase composition and optimizing surface hardening in plasma-nitrided 25Cr2Ni4W steel.

Abstract: The primary objectives of endodontic treatment are achieving a three-dimensional filling of the root canals with an atoxic, stable material, and creating an hermetically sealed apical area [1]; [2]. The filling of the canals, prevention of communication between the periodontal and endodontic spaces, and the mechanical preparation and irrigation are all essential steps to counteract the defense mechanisms of bacteria [1]; [2]; [3]; [4]; [5]. Gutta-percha, along with cement, has been successfully used, like core materials, for filling the root canal space. However, a hermetic seal cannot be achieved without the use of cement. This is because gutta-percha is unable to adhere to the dentinal walls of the canals, and the cement plays a critical role in filling imperfections and enhancing adhesion [6], [7]. It has been reported that some cements shrink during setting, while others are subject to dissolution when in contact with tissue fluids [8]; [9]. Nevertheless, the amount of cement used should be kept to a minimum, while the amount of gutta-percha should be maximized to the greatest extent possible in order to optimize the filling of the canal [10]; [11]. Many techniques have achieved good adaptability for three-dimensional root canal obturation. One of the first described is the hot vertical condensation technique. Among the more modern techniques, SoftCore aims to fill the canal with heated “alpha guttapercha”, which contains a plastic carrier made of polysulfone [12]; [13]. In contrast, the Guttafusion technique, also a hot vertical condensation core technique, uses a carrier made from crosslinked gutta-percha (hardened gutta-percha with a modified lattice structure) [14]; [15]. To assess the quality of the root canal obturation, techniques such as cross-sectional analysis of obturated canals, infiltration tests, and the combination of both have been widely used. The methodology followed in our study is based on approaches used in previous studies by significant authors [16]; [17]; [18]; [19]. Some previous studies [20]; [21] have evaluated the possibility of avoiding the combination of endodontic cement with carrier-based obturation techniques. However, in our view, there has been a continuous improvement over the years in root canal obturation techniques, particularly in apical preparation, as many studies report good filling percentages and effective minimization of void spaces. Our goal is to confirm the effectiveness of these techniques in root canal obturation by minimizing excess cement and optimizing the space occupied by cement, Gutta-percha and Void spaces. The two core techniques we compare, SoftCore and Guttafusion, will be examined to evaluate their efficiency in cement usage and the quality of the canal filling. This preliminary study aims to analyze two "core" root canal obturation systems: SoftCore and GuttaFusion, using the NeoSealer Flo sealer, and to compare the results between them. The primary objective of this study is to compare the percentage of the Gutta-Percha-filled areas in the canals obturated with SoftCore and GuttaFusion, both with the same bioceramic sealer.

Abstract: The sound absorption efficiency of the wood based sandwich panels with reinforced bas-alt fiber reinforced (BFRP), glass fiber reinforced (GFRP), and jute fabric composite materi-als and evaluate their potential as acoustic panels were investigated. Four experimental groups were created. Wood based sandwich panels were reinforced with BFRP (Group A), jute fabric (Group B), GFRP (Group C), and unreinforced (Group D). The sound absorption coefficients of the unreinforced and experimental groups were tested via the impedance tube method, according to ASTM standard E1050 (2006). Attention was paid to the acoustic behavior at low frequencies (200 Hz to 800 Hz), mid frequencies (1000 Hz to 1600 Hz), and high frequencies (1800 Hz to 2400 Hz). The sound absorption coefficient was highest in sapwood at 200 Hz frequency level with 0.67, while the highest in heartwood was 0.05 at 2400 Hz frequency level. It can be suggested that the experimental groups be used as sound absorbing acoustic panels.

Abstract: Lab on a Chip devices offer high efficiency, low volume and fast analytical measurement, but their use is still niche. A key component for these devices is the detector, and one common type of detection is fluorescence spectroscopy. However, in some cases the detector can be bulky and lose the appeal of small footprint devices. To make lab-on-a-chip devices truly compact, detectors must also be compact. In this paper we discuss the use of simple and low-cost commercial multispectral sensors for use in lab on a chip devices, more specifically for fluorescence detection. Which we demonstrate to allow detection on nanomolar scale with a very simple set up.

Abstract: Materials that store a significant amount of heat in a narrow temperature range by phase change solid-liquid or solid-solid are called Phase Change Materials (PCMs). Many PCMs are members of homologous groups of materials with similar composition and properties. Often, similarities are due to a common molecular composition with a repeating unit, e.g. for n-alkanes H-(CH2)n-H. Typical is an n related trend in the melting temperature. Based on observations on solvents, the question arises if such a trend also exists in eutectic binary mixtures with one component fixed while the other, from a homologous series, is varied. For verification, literature data were collected, specifically experimental data, each set with at least three variations from a single source. Eight data sets were collected, covering eutectic binary mixtures of n-alkanes, n-alkanols, and n-alkanoic acids. With one exception, all data sets show a systematic trend in the melting temperature and the composition. It is shown that the trends can be understood from thermodynamic theories of mixtures (Schröder – van Laar equation) combined with typical trends within homologous series. The findings offer new options in PCM development as well as the selection of PCM for specific application temperatures.

Abstract: The tracer diffusion of aluminium in the CuCr1Zr alloy was investigated, a material widely employed as an electrode in resistance spot welding. As a tracer layer, an alloy of Cu – 8.8 at.% Al was used, which was deposited by ion-beam sputtering. Isothermal diffusion annealing experiments were carried out between 500 and 700 °C, at temperatures relevant for industrial welding conditions. Al depth profile analysis was done by Secondary Ion Mass Spectrometry. The results revealed that aluminium exhibits a temperature-dependent diffusion behaviour. The diffusivities can be fitted together with literature data on Al diffusion in pure Cu obtained at higher temperatures according to the Arrhenius law. An activation enthalpy of 2 eV is obtained. The influence of a surficial oxide layer on the diffusion process is discussed.