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Hydrophobic eutectic solvent systems (ESSs) were prepared and characterized using temperature-dependent thermophysical and transport property measurements, supported by thermal analysis. The investigated systems comprise terpene-based mixtures, menthol:octanoic acid (1:2) and menthol:decanoic acid (1:1), and thymol-based mixtures, thymol:butanol (1:1), thymol:hexanol (1:1), thymol:octanoic acid (1:1), and thymol:oleic acid (1:1), as well as salt-containing ESSs based on tetrabutylphosphonium bromide (TBPBr), TBPBr:octanoic acid (1:1), and TBPBr:lauric acid (1:1). Density, dynamic viscosity, and electrical conductivity were measured at atmospheric pressure (p = 0.1 MPa) over 293.15–313.15 K. From density data, molar volumes and isobaric thermal expansion coefficients were calculated. The temperature dependence of viscosity was correlated with both Arrhenius and Vogel–Fulcher–Tammann equations. Conductivity results were used to compute molar conductivities, and the coupled conductivity–viscosity behavior was assessed via Walden analysis to quantify deviations from ideal electrolyte behavior and estimate ionicity. Thermal behavior and stability were evaluated by differential scanning calorimetry (DSC) and simultaneous thermogravimetric analysis (TG/DSC). The resulting dataset enables a consistent comparison of volumetric, flow, and ion transport descriptors across fully molecular terpene-based mixtures and TBPBr-containing systems. Overall, the combined transport descriptors, including Walden analysis, provide a practical framework for distinguishing molecular from salt-containing hydrophobic ESS families and support formulation selection for temperature-dependent applications, particularly in biphasic extraction processes.

This study focuses on the analysis of the absorption spectra of cobalt(II) nitrate and cobalt(II) bromide complexes in the x Ca(NO 3 ) 2 –(1 −  x )NH 4 NO 3 –H 2 O system. Measurements were conducted within the wavelength range of 400–800 nm, at a constant temperature of T  = 328.15 K and atmospheric pressure of p  = 101.3 kPa. The spectra were recorded for systems with a fixed salt composition of 0.3Ca(NO 3 ) 2 –0.7NH 4 NO 3 –H 2 O, but with varying water content, described by the mole ratio of water to salt ( R  = H 2 O/salt), where R was set to 1.0, 1.2, and 1.6. Additionally, the study investigated systems with varying calcium nitrate-to-ammonium nitrate ratios, represented as x Ca(NO 3 ) 2 –(1 −  x )NH 4 NO 3 –H 2 O, where x takes the values 0.3, 0.4, and 0.6. In these systems, the mole ratio of water to total salt was kept constant at R  = 1.6. For systems with x  = 0.7 and 0.9, a higher water-to-salt mole ratio of R  = 3.6 was used. The analysis of absorption spectra revealed a shift of the maximum absorption peak toward shorter wavelengths (blue shift) as the water content ( R ) increased. This behavior suggests that both water molecules and nitrate ions participate in the coordination around the cobalt(II) ion. Based on the spectral data, the presence of the following complexes was confirmed: [Co(NO 3 ) 4 (H 2 O) 2 ] 2− , [Co(NO 3 ) 2 Br 2 ] 2− and [CoBr 4 ] 2− . The overall stability constants of these complexes were calculated, and the corresponding resolved spectra of the species were determined at T  = 328.15 K.

The main goal of this study was to evaluate the concentration and release dynamics of molecular hydrogen (H2 , dihydrogen) in dietary evaluate supplements and identify products that provide a biologically significant amount of dihydrogen suitable for human consumption. We examined ten commercial supplements marketed for their dihydrogen content, including slow-release capsules and tablets (4 products), effervescent powders and tablets (5 products), and canned ready-to-drink beverage (1 product). These products were acquired either through online purchases, from retail stores, or obtained free of charge directly from the manufacturers upon request. Dihydrogen concentration was measured using a highly sensitive Clark-type hydrogen microsensor with a detection limit 0.05 µmol·L–1. Out of the ten products examined, only three (30.0%) exhibited dihydrogen levels surpassing the levels marketed as biologically relevant (500 µmol·L–1), and one of these products (a canned ready-to-drink beverage) approached this level with a concentration of 439.2 µmol·L–1. Interestingly, all slow-release capsules yielded negligible amounts of hydrogen (< 2 µmol·L–1), while a slow-release tablet delivered 43.6 µmol·L–1 of dihydrogen per single dose. The substantial variance in dihydrogen content among the assessed supplements holds significant implications for the general public, as high-potency products have the potential to provide up to 7 000 times more dihydrogen per single dosage compared to their low-potency counterparts.

A powdered PVA/CaCO 3 nanocomposite carrier was successfully fabricated for effective loading of small bioactive molecules, such as vitamin D 3 (VD 3 ). Generation of, namely, VD 3 /PVA/CaCO 3 nanocomposite scaffold was carried out through an adsorption mechanism as a loading route of an active compound onto a powder carrier. Developed composites were characterized by structural, morphological and thermal analyses techniques, such as X-ray powder diffraction (XRPD), Fourier-transform infrared (FTIR) spectroscopy, MALDI (matrix-assisted laser desorption/ionization) – mass spectrometry (MS), Brunauer–Emmett–Teller (BET) – NLDFT (Non-local Density Functional Theory) method, scanning electron microscopy (SEM), simultaneous TG-DTG and coupled TG-MS. XRD results showed that the average crystallite size of synthesized VD 3 /PVA/CaCO 3 amounts 32.93 nm exhibiting microstrain presence, where PVA incorporation causes non-uniform calcite lattice distortion. SEM analysis showed that VD 3 /PVA/CaCO 3 nanocomposite scaffold contains agglomerated rhomboidal calcite particles with VD 3 particles of irregular shapes attached. Fabricated VD 3 /PVA/CaCO 3 clearly showed the existence of calcite “ staircase ” dendrites as the aftermath of inhibiting the effect of impurities on the growth of crystals in normal directions. It was determined that the decomposition of PVA additionally enhances the thermal stability of VD 3 , through the stabilization effect by acting on van der Waal’s forces during polyene formation, confirmed by MALDI-TOF MS results.

Guanidinoacetic acid (GAA) is an experimental dietary additive that might act as a creatine source in tissues with high-energy requirements. In this case study, we evaluated brain levels of creatine in white matter, gray matter, cerebellum, and thalamus during 8 wk oral GAA administration in five healthy men and monitored the prevalence and severity of side effects of the intervention. Volunteers were supplemented daily with 36 mg/kg body weight (BW) of GAA for the first 4 wk of the intervention; afterward GAA dosage was titrated ≤60 mg/kg BW of GAA daily. At baseline, 4, and 8 wk, the participants underwent brain magnetic resonance spectroscopy, clinical chemistry studies, and open-ended questionnaire for side-effect prevalence and severity. Brain creatine levels increased in similar fashion in cerebellum, and white and gray matter after GAA supplementation, with an initial increase of 10.7% reported after 4 wk, and additional upsurge (7.7%) from the weeks 4 to 8 follow-up (P < 0.05). Thalamus creatine levels decreased after 4 wk for 6.5% (P = 0.02), and increased nonsignificantly after 8 wk for 8% (P = 0.09). GAA induced an increase in N-acetylaspartate levels at 8-wk follow-up in all brain areas evaluated (P < 0.05). No participants reported any neurologic adverse event (e.g., seizures, tingling, convulsions) during the intervention. Supplemental GAA led to a region-dependent increase of the creatine pool in the human brain. This might be relevant for restoring cellular bioenergetics in disorders characterized by low brain creatine and functional enzymatic machinery for creatine synthesis, including neurodegenerative diseases, brain tumors, or cerebrovascular disease. •Guanidinoacetic acid (GAA) is an experimental dietary supplement and alternative creatine source.•Dietary GAA increased brain creatine ≤19.1% after 8 wk supplementation in healthy men.•GAA loading was accompanied by impaired methylation profiles in the circulation and brain

Caffeine is a popular ergogenic aid in high-intensity sports, but it can cause side effects like cardiovascular stress and tolerance buildup. Theacrine, a structurally similar purine alkaloid, may offer comparable performance benefits with fewer adverse effects. This study aimed to assess the acute effects of theacrine, caffeine, and their combination on performance and physiological responses in elite canoe sprint athletes. Twenty highly trained male canoe sprint athletes participated in a randomized, double-blind, placebo-controlled, crossover trial with four conditions: placebo ( ), caffeine (K), theacrine (T), and a combination of caffeine and theacrine (KT). Each participant completed a 500-meter time trial and a 30-second Wingate Anaerobic Test (WAnT) on a kayak ergometer under each condition. Primary outcomes included race time, power output, muscle oxygen saturation (SmO₂), total hemoglobin (THb), and maximal accumulated oxygen deficit (MAOD), which were measured using near-infrared spectroscopy (NIRS) and VO₂ analysis. Caffeine significantly improved the 500-meter time trial (-1.872 s vs. ,  < 0.001) and WAnT distance (+2.31 m,  = 0.005), while KT produced smaller but still significant effects. Theacrine alone (T) did not lead to statistically significant performance improvements. Caffeine increased MAOD (  < 0.005), whereas KT and T showed non-significant changes. SmO and THb slopes were not significantly affected in any condition, suggesting that performance gains were mediated by mechanisms other than local oxygen delivery. No significant differences were observed in heart rate, blood pressure, or perceived exertion across conditions. Strong negative correlations between race time and power output-especially under caffeine-indicated that mechanical output is the primary factor influencing performance. Caffeine remains a powerful ergogenic aid in sprint paddling, enhancing both mechanical output and muscle oxygen utilization. Although theacrine alone showed limited ergogenic effects, its combination with caffeine produced additional improvements compared to placebo, indicating a possible complementary role. These findings support targeted supplementation strategies in elite sports.

ABSTRACT Background Energy requirements during high-intensity exercise rapidly escalate. Phosphocreatine, being the major compound utilized to rapidly replenish the ATP levels, essentially relies on creatine stores which may experience fluctuations in its utilization, transport or release across various bodily fluids. So far, no studies have assessed whether exercise affects salivary biomarkers of creatine metabolism, or whether these metabolites in saliva mirror those found in the serum. Method Sixteen healthy adults volunteered in this open-label crossover pilot study. All participants were subjected to the running-to-exhaustion treadmill protocol, starting with a 3-minute warm-up at 5 km/h, progressively increasing the workload by 1.5 km/h every minute. Fasted blood samples were collected from the antecubital vein and unstimulated whole saliva was collected from beneath the tongue ~ 30 minutes before and immediately after intervention. All samples underwent analysis for creatine and creatinine using a modified liquid chromatography–tandem mass spectrometry. Differences were compared using paired two-tailed t-test and Pearson’s correlation was used to evaluate the linear relationship. Results Fifteen participants (23.9 ± 2.9 years, eight females) were analyzed for the study outcomes. In contrast to serum, salivary creatine and creatinine levels significantly elevated pre- to post-exercise (17.5 ± 14.2 µmol/L to 43.6 ± 30.4 µmol/L and 11.3 ± 5.8 µmol/L to 17.0 ± 9.3 µmol/L, P < 0.001, P = 0.04). Salivary creatine and creatinine metabolism showed a non-significant correlation with the corresponding serum biomarkers at baseline (r = 0.18, P = 0.51, and r < 0.01, P = 0.99) and after the exercise (r = 0.33, P = 0.21 and r = 0.40, P = 0.13). Conclusion Our preliminary findings suggest a potential difference in the exercise-induced dynamics of creatine metabolism across the two bodily fluids, warranting further research into using saliva as simple and non-invasive proxy for creatine turnover and biodynamics.

The present study analyzed experimental data from volumetric and viscosimetric measurements and computational simulations to understand caffeine hydration and aggregation properties in 0.1 mol∙kg−1 of sodium salicylate aqueous solution. Sodium salicylate reduces the bitter taste and increases the solubility of caffeine in water, which is the main reason for their combination in food products. The results noted in volumetric and viscosimetric measurements indicate that sodium salicylate promotes the self-aggregation of caffeine in water. After self-aggregation, the hydration number of caffeine significantly increases. Molecular simulations have allowed us to hypothesize how salicylate increases caffeine solubility. At the molecular level, relocating salicylate moiety from the parallel stacking (π–π) aromatic complex with caffeine and its hydration could be the main reason for increasing the solubility of caffeine in water. The presented study provides clear guidelines on the choice of additives to increase caffeine’s solubility in aqueous media. The choice of salicylate as an additive to increase the solubility of caffeine is very important because caffeine and salicylate are found in combination in a large number of formulations.

This paper reviews the biological and environmental aspects of imidazole derivatives and their potential as insect growth regulators (IGRs). Imidazoles, known for their broad pharmacological and pesticidal properties, act on insect hormonal systems by inhibiting the biosynthesis of juvenile hormone and ecdysone, leading to developmental disruption, premature metamorphosis, or mortality. Particular emphasis is placed on the compound KK-42, which shows significant effects across several insect orders. Although commercially available imidazoles are currently registered as fungicides, their selective activity, low toxicity, and synergistic potential with other pesticides make them promising candidates for developing new insecticidal agents. The paper also discusses their environmental toxicity and compatibility with beneficial organisms, highlighting the need for further research to minimize ecological risks and promote sustainable pest management in agriculture.

In this work, the absorption spectra of cobalt(II) nitrate and chloride complexes in the composition xCa(NO3)2–(1 – x)NH4NO3–H2O have been investigated in the 400–800 nm range of wavelength at T = 328.15 K and atmospheric pressure p = 101.3 kPa. Spectra were recorded in 0.3 Ca(NO3)2–0.7 NH4NO3–H2O solutions with variable water content (R = H2O/salt mole ratio; Rws = 1.0, 1.2, 1.6 and 2.0), and in xCa(NO3)2–(1 – x)NH4NO3–H2O (x = 0.3, 0.5 and 0.7) solutions where the H2O/salt mole ratio was kept constant (Rws = 2.0). The blue shift of the absorption maximum with increasing water content (Rws) suggests simultaneous coordination by water molecules and nitrate ions. From an analysis of the spectra, it can be concluded that the following complexes: [Co(NO3)4(H2O)2]2−, [Co(NO3)2Cl2]2− and [CoCl4]2− were formed. The overall stability constants of these complexes and the corresponding resolved species spectra were calculated at T = 328.15 K.