Bacterial cellulose (BC) is a unique microbial biopolymer with a huge number of significant applications in the biomedical field, including bone tissue engineering. The present study proposes to obtain and characterize BC hybrid composites with calcium phosphate as biocompatible and bioactive membranes for bone tissue engineering. BC precursor membranes were obtained in static culture fermentation, and after purification, were oxidized to obtain 2,3-dialdehyde bacterial cellulose (DABC). Calcium phosphate-BC oxidized membranes were produced by successive immersion in precursor solutions under ultrasonic irradiation. The samples were characterized for their physicochemical properties using scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy grazing incidence X-ray diffraction (GI-XRD), solid-state ¹³C nuclear magnetic resonance (CP/MAS ¹³C NMR), and complex thermal analysis. In vitro cell studies were also performed to evaluate the influence of modified morphological characteristics on cell adhesion and proliferation. The results showed an increase in porosity and biodegradability for DABC hybrid composites compared with BC. In vitro cell studies have revealed that both hybrid composites favor cell adhesion to the surface. The new BC and DABC hybrid composites with calcium phosphate could be considered promising materials for bone tissue regeneration.

A new heteronuclear decoupling pulse sequence is introduced, dubbed ROtor-Synchronized Phase-Alternated Cycles (ROSPAC). It is based on a partial refocusing of the coherences (spin operator products or cross-terms) [Filip et al., J. Mag. Reson. 176, 2 (2005)] responsible for transverse spin-polarization dephasing, on the irradiation of a large pattern of radio-frequencies, and on a significant minimization of the cross-effects implying ¹H chemical-shift anisotropy. Decoupling efficiency is analyzed by numerical simulations and experiments and compared to that of established decoupling sequences [swept-frequency two-pulse phase-modulated (TPPM), TPPM, small phase incremental alternation (SPINAL), refocused Continuous-wave (CW^Apa), and Rotor-Synchronized Hahn-Echo pulse train (RS-HEPT)]. It was found that ROSPAC offers good ¹H offset robustness for a large range of chemical shifts and low radio-frequency (RF) powers, and performs very well in the ultra-fast magic-angle spinning (MAS) regime, where it is almost independent from RF power and permits it to avoid rotary-resonance recoupling conditions (v₁ = nv_r, n = 1, 2). It has the advantage that only the pulse lengths require optimization and has a low duty cycle in the pulsed decoupling regime. The efficiency of the decoupling sequence is demonstrated on a model microcrystalline sample of the model protein domain GB₁ at 100 kHz MAS at 18.8 T.

Biosolids from stabilized sludge present a high fertilization potential, due to their rich content of nutrients and organic matter. The intrinsic and subtle properties of such fertilizers may greatly influence the fertilization efficiency. In this sense, the utility, advantages and limitations of advanced characterization methods, for the investigation of structural and dynamic properties at the microscopic scale of slightly different formulations of fertilizers were assessed. For that, three formulas of organo-mineral fertilizers based on biosolids (V1, V2 and V3), having at least 2% N, 2% P₂O₅, and 2% K₂O, were characterized by advanced methods, such as ¹H NMR relaxometry, ¹H MAS and ¹³C CP-MAS NMR spectroscopy, ¹H double-quantum NMR and FT-IR spectroscopy. Advanced structural characterization was performed using SEM, EDX and X-ray diffraction. Four dynamical components were identified in the NMR T₂ distribution showing that the rigid component has a percentage larger than 90%, which explains the broad band of NMR spectra confirmed by the distributions of many components in residual dipolar coupling as were revealed by ¹H DQ-NMR measurements. SEM and EDX measurements helped the identification of components from crystalline-like X-ray diffraction patterns. To evaluate the release properties of organo-mineral fertilizers, dynamic measurements of classical electric conductivity and pH were performed by placing 0.25 g of the formulas (V1, V2 and V3) in 200 mL of distilled water. The content of N and P were quantified using specific reactants, combined with VIS-nearIR spectroscopy. Two release mechanisms were observed and characterized. It was found that V3 presents the smallest release velocity but releases the largest number of fertilizers.

Archaeological ceramics preserve key evidence of ancient production technologies and material sources, yet their amorphous components often hinder full structural analysis. This study combines solid-state NMR (1H, 27Al, 29Si, 31P MAS NMR) with XRD and SEM/EDX to investigate Romanian ceramics from three archaeological sites: Capidava, Tilișca, and Șura Mare. NMR revealed variations in aluminum coordination, silicate polymerization, and phosphate environments, reflecting differences in firing conditions and post-depositional changes. XRD identified quartz, muscovite, feldspars, and corundum, while SEM/EDX showed heterogeneous microstructures and elemental distributions. The results highlight the unique value of solid-state NMR in probing short-range order and amorphous phases, complementing the structural and morphological insights obtained by XRD and SEM. This integrated approach provides a coherent multi-scale understanding of ancient ceramic technologies and their transformation within archaeological contexts.