Academy of Sciences of Moldova

Skin wounds pose significant clinical and economic challenges, driving the need for advanced dressing materials capable of protecting the injury, supporting tissue regeneration, maintaining moisture, and preventing infection. Polysaccharide-based hydrogels have gained attention for these applications due to their hydrophilicity, biocompatibility, and repair-promoting properties. In this work, we developed a fully aqueous ink for direct ink writing (DIW) 3D printing composed of N-(2-hydroxy)-propyl-3-trimethylammonium chitosan chloride (HTCC), beta-chitin whiskers (ChW), and genipin as a nontoxic cross-linker. HTCC, a cationic and water-soluble chitosan derivative, was synthesized via reaction with glycidyltrimethylammonium chloride, while ChW were produced by acidolysis of beta-chitin, yielding high-aspect-ratio nanocrystals. Their combination generated a composite ink with synergistic features: HTCC provided cationic functionality and solubility, whereas ChW imparted mechanical reinforcement and anisotropy. Notably, ChW significantly strengthened the hydrogel network, increasing the compressive modulus from 5.9 to 24.1 kPa and the tensile strength from 19.3 to 78.0 kPa, representing a 4-fold improvement. The formulation displayed rheological properties suitable for DIW, including viscoelasticity, shear-thinning behavior, and rapid thixotropic recovery. Such features enabled high-resolution 3D printing of asymmetric membranes with a dense outer layer (OL) and a porous inner layer (IL) with a honeycomb-like microarchitecture. The membranes were effectively cross-linked by genipin, remained stable in physiological buffer, and exhibited controlled enzymatic degradation in lysozyme. Besides, both OL and IL demonstrated contact-active antibacterial activity against Staphylococcus aureus and Escherichia coli , arising from the polyelectrolytic nature of HTCC. Importantly, assays using mouse fibroblast assays confirmed that the material extracts were noncytotoxic. Taken together, these results demonstrate that HTCC/ChW-based asymmetric hydrogels constitute a sustainable and multifunctional platform for wound dressings, integrating structural asymmetry, biodegradability, mechanical robustness, and intrinsic antibacterial properties.

WO3 thin films were prepared by RF sputtering metallic tungsten onto glass substrates, followed by thermal oxidation through annealing in air. This technique is straightforward, cost-efficient, and time-effective, achieving high deposition rates of 16 nm/min on average at 200 W magnetron power for the highly homogeneous W-metallic films. SEM/EDX analysis showed that after annealing at 450?C in air, the RF sputtered 269 nm thick metallic W films with a round grain morphology (~30 nm) turned into 420 nm thick nearly stoichiometric transparent WO3 (tungsten (VI) oxide) film, with a dramatically changed morphology of aggregated crystal rods approximately 1 ?m long. XRD and Raman spectroscopy confirmed a biphasic crystal structure, with a dominant monoclinic phase and a minor tetragonal phase. XPS analysis revealed the characteristic W4f7/2 and W4f5/2 electron peaks associated with the W6+ oxidation state, with no evidence of W5+ species, indicating a stoichiometric nature of the WO3 films.

Most of the materials' mechanical performance is fixed after the material is manufactured. Here, inspired by the three rotational symmetry leaves in natural plants, we introduced two 2D mechanical metamaterials, line-to-line connected clover structure (CLC) and point-to-point connected clover structure (CPC). Thanks to the different bending direction of the clover structure during buckling, these structures exhibiting switchable deformation modes and Poisson's ratio. Theoretical expressions on Poisson's ratio of the CLC and CPC metamaterials are established to relate to the angle between the triangles of the clover structure, showing good agreement with numerical simulations as well as experimental results. Mechanical training was performed on the CLC metamaterial to obtain different deformation modes. Experiment results showed that Poisson's ratio of the CLC metamaterials can be trained to switch between positive and negative. Similar to the rotating rigid triangle structure, Poisson's ratio of the CLC and CPC metamaterials was governed by the rotation of the triangles in their structures. Poisson's ratio of the CPC metamaterials can reach −1 at two perpendicular directions. The proposed CLC and CPC metamaterials are expected to find applications in smart sensors, energy absorption devices, actuators, and wave convertors, especially in environments of alternating mechanical changes.

The text aims to offer a personalized evocation of the work and destiny of the great Romanian poet, Nicolae Labiș (1935–1956), who passed away at a very young age following a (mysterious) nocturnal tram accident. A review of his major editorial publications is followed by the mention of several critical echoes and interpretations that have shaped the perception of the Poet’s work and personality over time. The overall evocation and the hermeneutic interpretation of his main poetic symbols – the roe deer, the stag, the mountains, and the forest – are complemented by the impact of Labiș’s poetry within the Bessarabian cultural space.

În cadrul Sesiunii a XIX-a a Adunării Generale a Academiei de Științe a Moldovei din 12 mai 2026, a fost audiat și aprobat Raportul asupra stării științei din Republica Moldova în anul 2025, prezentat de academicianul Ion Tighineanu, președintele AŞM. Raportul sintetizează date privind potențialul științific, pregătirea cadrelor și rolul tinerilor în cercetare, nivelul finanțării domeniului, vizibilitatea acestuia pe plan național și internațional, integrarea în Spațiul European și internațional de cercetare, audierile publice și raportarea implementării proiectelor din domeniile cercetării și inovării. Totodată, sunt evidențiate contribuțiile experților în domeniile de competență, realizate pe baza platformelor de dialog și a comisiilor de specialitate, alături de rezultatele științifice și inovatoare, calitatea cercetărilor, impactul și implementarea acestora în științele medicale, agricole, biologice și de mediu, exacte și inginerești, precum și în cele sociale, economice, umanistice și în arte.