We report an ultrafast method for producing metal-free carbon nano-onions (CNOs) by tungsten-assisted microwave (MW) irradiation of nanodiamond (ND) precursors. In contrast to conventional pyrolysis, which typically requires temperatures above 1650 degrees C, complete ND-to-CNO conversion is achieved within 45 s at 700 W. Tungsten serves as a plasma initiator and field-localization element, enabling rapid graphitization without detectable tungsten incorporation into the final material. Structural analyses confirm the formation of quasispherical multilayer CNOs with predominantly sp2-hybridized C atoms. At the same time, the layers' regularity and defect density depend strongly on the surface chemistry of the starting NDs. Broadband dielectric spectroscopy shows that the resulting CNOs are up to 8 orders of magnitude more conductive than the parent NDs and CNOs obtained by the high-temperature pyrolysis, and exhibit enhanced dielectric response, indicating efficient charge transport and charge accumulation. Nitrogen sorption reveals moderate surface areas and predominantly interparticle mesoporosity. In 0.1 M NaCl, all CNOs display electric double-layer capacitive behavior, with specific capacitances of 146.6, 76.2, and 45.4 F g- 1 for CNO Molto, CNO Amine, and CNO Vox, respectively, demonstrating that capacitive performance is governed by layer ordering, conductivity, and pore accessibility rather than by surface area alone. In an alkaline electrolyte, the CNOs also exhibit oxygen-reduction activity characteristic of defect-containing sp2 carbon frameworks. These results establish tungsten-assisted MW processing as a rapid route to structurally tunable CNOs with coupled electrical, capacitive, and electrocatalytic functionality.

The interplay between defects, heteroatom doping, and surface curvature in carbon nanostructures governs their electronic transport and catalytic properties, yet it remains poorly understood. Here, we elucidate how structural defects, N/O functionalities, and high curvature collectively modulate morphology, conductivity, and oxygen reduction reaction (ORR) activity in carbon nano-onions (CNOs) derived from nanodiamonds (NDs). Ultradispersed NDs with tailored surface terminations are thermally transformed at 1,150 and 1,650 degrees C to generate partially graphitized core-shell nanostructures and fully converted, highly graphitized CNOs, respectively. X-ray photoelectron spectroscopy and electrochemical analysis reveal that pyridinic- and graphitic-N and carbonyl/phenolic O at curvature-induced defect sites define the defect chemistry, enabling fine control over charge transport and interfacial reactivity. Rotating ring-disk electrode studies show that optimally graphitized, defect-accessible CNOs (1,650 degrees C) deliver high specific capacitances, near-diffusion-limited ORR currents, with the number of electrons transferred per O2 molecule during ORR approximately 4.0, and a <= 10% H2O2 selectivity in alkaline media. Within a curvature-engineering framework, concentric graphenic layers introduce a Gaussian curvature that concentrates local fields and tunes *OOH binding, while continuous sp2 networks minimize resistive losses. This work establishes a structure-property-function concept for "curved" nanocarbons and defines design rules for next-generation, metal-free CNO electrocatalysts.

We report the first ionothermal synthesis of nitrogen- and sulfur-containing covalent triazine frameworks (CTFs) from NS (thiazolo-[5,4-d]-thiazole derivative), SS (thieno-[2,3-b]-thiophene derivative), and NSN (benzo-[c]-[1,2,5]-thiadiazole derivative) monomers and their hybrids with carbon nano-onions (CNOs). All materials were synthesized by pyrolysis at 700 °C. Comprehensive characterization by Fourier transform infrared spectroscopy, powder X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy (HRTEM) shows that the materials consist of turbostratic, heteroatom-doped carbon frameworks in which CNOs introduce small graphitic crystallites and quasi-crystalline ordering. Triazine ring formation, and the presence of pyridinic/graphitic N together with C-S-C/CS motifs confirm successful incorporation of heteroatoms into a π-conjugated carbon matrix, whereas HRTEM reveals concentric graphitic CNO shells intimately embedded in an amorphous-to-locally graphitic CTF phase, yielding strong interfacial contact and an interconnected porous architecture. The CTF-CNO hybrids show up to a 3-fold increase in specific capacitance relative to the corresponding pristine CTFs and retain high capacitance over a wide range of scan rates and current densities. NS-CTF-CNO combines a favorable balance of energy and power densities, low charge-transfer resistance, and a wide operational potential window, while NSN-CTF-CNO achieves the highest specific capacitance (1074 F g-1 at 10 mV s-1). These results establish a design strategy in which heteroatom-rich CTF frameworks are integrated with near-percolating CNO networks and tuned pore connectivity to optimize conductivity, ion transport, and fast, reversible charge storage in metal-free carbon electrodes.

The increasing prevalence of antimicrobial resistance highlights the urgent need for new antimicrobial agents with improved efficacy and safety profiles. Cannabichromene (CBC) is a non-psychoactive phytocannabinoid with reported antibacterial activity, but its limited chemical stability restricts broader therapeutic applications. In this study, we designed and synthesized a novel series of hybrid cannabichromene-based imidazolium salts (CBC-IMSs) that combine a cannabinoid scaffold with a membrane-active imidazolium moiety. The resulting CBC-IMSs exhibited enhanced chemical stability compared to the parent CBC. The target compounds were synthesized via an efficient five-step route, four stages of which were performed under microwave irradiation, reducing reaction times from hours to minutes and improving overall yields. The structures of all derivatives were confirmed by NMR, FTIR, HRMS, and elemental analysis. Antibacterial activity was evaluated using an ATP-based luminescence assay against Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa. All derivatives showed potent activity against S. epidermidis, with IC50 values in the range of 1.0-5.2 µM, while limited activity was observed against Gram-negative strains. Structure–activity analysis indicated that the length of the N-alkyl side chain plays a key role in modulating antibacterial potency, with the butyl-substituted derivative (CBC-C4) identified as the most active compound. In silico ADMET predictions suggest favorable drug-like properties and low toxicity risk for the synthesized compounds. Overall, these findings demonstrate that CBC-IMS hybrids represent a promising starting point for developing stable cannabinoid-based antimicrobial agents targeting Gram-positive bacteria.

Wounds are undeniably important gateways for pathogens to enter the body. In addition to their detrimental local effects, they can also cause adverse systemic effects. For this reason, developing methods for eradicating pathogens from wounds is a challenging medical issue. Polymers, particularly hydrogels, are one of the more essential materials for designing novel drug-delivery systems, thanks to the ease of tuning their structures. This work exploits this property by utilizing copolymerization, microwave modification, and drug-loading processes to obtain antibacterial gels. Synthesized xylitol-modified glycidyl methacrylate-co-ethyl methacrylate ([P(EMA)-co-(GMA)]-Xyl]) matrices were loaded with bacitracin, gentian violet, furazidine, and brilliant green, used as active pharmaceutical ingredients (APIs). The hydrophilic properties, API release mechanism, and antibacterial properties of the obtained hydrogels against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus epidermidis containing [P(EMA)-co-(GMA)]-Xyl] were studied. The hydrogels with the APIs efficiently inhibit bacteria growth with low doses of drugs, and our findings are statistically significant, confirmed with ANOVA analysis at p = 0.05. The results confirmed that the proposed system is hydrophilic and has extended the drug-release capabilities of APIs with a controlled burst effect based on [P(EMA)-co-(GMA)]-Xyl] content in the hydrogel. Hydrogels are characterized by the prolonged release of APIs in a very short time (a few minutes). Although the amount of released APIs is about 10%, it still exceeds the minimum inhibitory concentrations of drugs. Several kinetic models (first-order, second-order, Baker–Lonsdale, and Korsmeyer–Peppas) were applied to fit the API release data from the [P(EMA)-co-(GMA)]-Xyl-based hydrogel. The best fit of the Korsmeyer–Peppas kinetic model to the experimental data was determined, and it was confirmed that a diffusion-controlled release mechanism of the APIs from the studied hydrogels is dominant, which is desirable for applications requiring a consistent, controlled release of therapeutic agents. A statistical analysis of API release using Linear Mixed Model was performed, examining the relationship between % mass of API, sample (hydrogels and control), time, sample–time interaction, and variability between individuals. The model fits the data well, as evidenced by the determination coefficients close to 1. The analyzed interactions in the data are reliable and statistically significant (p < 0.001). The outcome of this study suggests that the presented acrylate-based gel is a promising candidate for developing wound dressings.

Oxidation processes affect the structural integrity of carbon nanostructure (CN), leading to changes its physico-chemical properties, as a result of oxidation of sp2-hybridized carbon atoms, and formation of appropriate functional groups, further determining the surface properties of CNs. This work used several oxidation methods to develop effective procedures for the selective modification of the carbon nano-onion (CNO). Hydrogen peroxide, urea hydrogen peroxide complex, acetic chloride or anhydride, and trifluoroacetic acid were used as the primary reagents in various configurations for the functionalization of CNOs, which resulted in the formation of oxygen-containing groups, mainly carbonyls, phenolic, carboxyl, ethers, and esters. The dispersion of functionalized CNOs was tested in a series of protic, aprotic polar, and nonpolar solvents that were used to determine the Hansen Solubility Parameters. The dispersion of oxidized CNOs was determined experimentally in water, by designating the zeta potential of dispersed CNOs and their diameters using dynamic light scattering. The formation of oxygen-containing groups ensures high dispersion of CNs in polar solvents and provides high stability in water for more than two months. It is the first work describing such effective methods of functionalizing spherical nanostructures containing C(sp2)-hybridized carbon atoms, where the dispersion stability in water is so significant.

The IRIS group of IFIC-Valencia has developed a Compton camera prototype for medical imaging. The prototype MACACO is being tested for radiopharmaceutical imaging. First tests with different medical radiotracers in phantoms and patients pointed out the necessity of a detector with improved detection efficiency. For this purpose, MACACO III+, a new prototype version with an enlarged second detector area, has been assembled. Recently, experimental tests with the improved system have been conducted in the hospital La Fe with 131 I-MIBG using two different phantoms. Results of functional tests performed in the laboratory, as well as reconstructed images of the phantoms filled with the medical radionuclide are presented.

We report biochemical and structural studies on inhibiting bacterial S-adenosyl-L-homocysteine hydrolase by transition metal cations. Our results revealed diverse molecular mechanisms of enzyme inactivation. Depending on the cation, the mechanism is based on arresting the enzyme in its closed, inactive conformation, disulfide bond formation within the active site or oxidation of the intermediate form of a cofactor.

Covalent triazine frameworks (CTFs) constitute an emerging class of high-performance materials due to their porosity and the possibility of structural control at the molecular or atomic level.