Search Results (335)

The ancient Roman town of Turris Libisonis was located on the northern coast of Sardinia and was known in the past as an important naval port. Located in the Gulf of Asinara, it was a Roman colony from the 1st century BCE and became one of the richest towns on the island. Among the archaeological finds in the area, the cippus exhibited in the Antiquarium Turritano is of great interest for its well-preserved traces of polychromy. The artefact dates back to the early Imperial Age and could have had a funerary or votive function. The artefact was first examined using a portable and non-invasive protocol involving multi-band imaging (MBI), portable X-ray fluorescence (p-XRF), portable FT-IR in external reflectance mode (ER FT-IR) and Raman spectroscopy. After this initial examination, a few microfragments were collected and investigated by optical microscopy (OM), X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy in ATR mode (ATR FT-IR) and micro-ATR mode (μATR FT-IR) and Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM-EDS) to improve our knowledge and characterize the materials and to determine their provenience. The results contribute to a better understanding of the provenance of materials and shed light on pigments on stone and their use outside the Italian peninsula and, in particular, Roman Sardinia. Full article

In this paper, we report the possibility of using the X-ray powder diffraction (XRPD) technique to detect gamma-hydroxybutyric acid (GHB) in the form of its sodium salt in different beverages, but because it is not possible to freely buy GHB, beta-hydroxybutyric acid (BHB) and its sodium salt (NaBHB) were used as a model to fine-tune an X-ray diffraction method for the qualitative analysis of the sodium salt of GHB. The method requires only a small quantity of beverage and an easy sample preparation that consists only of the addition of NaOH to the drink and a subsequent drying step. The dry residue obtained can be easily analyzed with XRPD using a single-crystal X-ray diffractometer, which exploits its high sensitivity and allows for very fast pattern collection. Several beverages with different NaBHB:NaOH molar ratios were tested, and the results showed that NaBHB was detected in all drinks analyzed when the NaBHB:NaOH molar ratio was 1:50, using a characteristic peak at very low 2θ values, which also permitted the detection of its presence in complex beverage matrices. Moreover, depending on the amount of NaOH added, shifting and/or splitting of the characteristic NaBHB salt peak was observed, and the origin of this behavior was investigated. Full article

In this work, the influences of La₂O₃ addition on the connectivity of the glass network, phase compositions and microstructural evolution of weld slag were investigated through Raman spectrum, X-ray powder diffraction (XRPD), SEM and EBSD technologies. All experimental results indicated that La₂O₃ addition could modify the whole glass network’s connectivity and short-ordered units. According to the Raman spectrum, only 1 wt.% La₂O₃ addition resulted in the occurrence of a unique linking mode of Si-O and Al-O tetrahedrons that was assigned to feldspar phases (albite or anorthite). Further XRPD examination showed that the primary phases were albite and anorthite, which agreed with the Raman results. Moreover, enhanced linkage between Si-O and Al-O tetrahedrons needs a large amount Na⁺ to achieve electric neutrality. This repaired the connectivity of the slag network due to the lack of Na⁺. Additionally, the solubility of La₂O₃ in the slag matrix was limited to about 3 wt.%. Adding further La₂O₃ to this weld slag, the existence form of La₂O₃ retained its original status. Thus, La₂O₃ addition that exceeded 3 wt.% had little effect on the slag connectivity besides providing a phase interface. In conclusion, La₂O₃ addition in weld slag could promote the hardness and the formation of feldspar phases. Feldspar is an extremely fragile silicon aluminate crystal. The factors mentioned above caused the detachability to be enhanced when adding La₂O₃. Full article

Additive manufacturing of pharmaceutical formulations offers advanced micro-structure control of oral solid dose (OSD) forms targeting not only customised dosing of an active pharmaceutical ingredient (API) but also custom-made drug release profiles. Traditionally, material extrusion 3D printing manufacturing was performed in a two-step manufacturing process via an intermediate feedstock filament. This process was often limited in the material space due to unsuitable (brittle) material properties, which required additional time to develop complex formulations to overcome. The objective of this study was to develop an additive manufacturing MicroFactory process to produce an immediate release (IR) OSD form containing 250 mg of mefenamic acid (MFA) with consistent drug release. In this study, we present a single-step additive manufacturing process employing a novel, filament-free melt extrusion 3D printer, the MicroFactory, to successfully print a previously ‘non-printable’ brittle Soluplus^®-based formulation of MFA, resulting in targeted IR dissolution profiles. The physico-chemical properties of 3D printed MFA-Soluplus^®-D-sorbitol formulation was characterised by thermal analysis, Fourier Transform Infrared spectroscopy (FTIR), and X-ray Diffraction Powder (XRPD) analysis, confirming the crystalline state of mefenamic acid as polymorphic form I. Oscillatory temperature and frequency rheology sweeps were related to the processability of the formulation in the MicroFactory. 3D printed, micro-structure controlled, OSDs showed good uniformity of mass and content and exhibited an IR profile with good consistency. Fitting a mathematical model to the dissolution data correlated rate parameters and release exponents with tablet porosity. This study illustrates how additive manufacturing via melt extrusion using this MicroFactory not only streamlines the manufacturing process (one-step vs. two-step) but also enables the processing of (brittle) pharmaceutical immediate-release polymers/polymer formulations, improving and facilitating targeted in vitro drug dissolution profiles. Full article

Binary As_xSe_100−x alloys from the border of a glass-forming region (65 < x < 70) subjected to nanomilling in dry and dry–wet modes are characterized by the XRPD, micro-Raman scattering (micro-RS) and revised positron annihilation lifetime (PAL) methods complemented by a disproportionality analysis using the quantum–chemical cluster modeling approach. These alloys are examined with respect to tetra-arsenic biselenide As₄Se₂ stoichiometry, realized in glassy g-As₆₅Se₃₅, glassy–crystalline g/c-As₆₇Se₃₃ and glassy–crystalline g/c-As₇₀Se₃₀. From the XRPD results, the number of rhombohedral As and cubic arsenolite As₂O₃ phases in As-Se alloys increases after nanomilling, especially in the wet mode realized in a PVP water solution. Nanomilling-driven amorphization and reamorphization transformations in these alloys are identified by an analysis of diffuse peak halos in their XRPD patterning, showing the interplay between the levels of a medium-range structure (disruption of the intermediate-range ordering at the cost of an extended-range one). From the micro-RS spectroscopy results, these alloys are stabilized by molecular thioarsenides As₄Se_n (n = 3, 4), regardless of their phase composition, remnants of thioarsenide molecules destructed under nanomilling being reincorporated into a glass network undergoing a polyamorphic transition. From the PAL spectroscopy results, volumetric changes in the wet-milled alloys with respect to the dry-milled ones are identified as resulting from a direct conversion of the bound positron–electron (Ps, positronium) states in the positron traps. Ps-hosting holes in the PVP medium appear instead of positron traps, with ~0.36–0.38 ns lifetimes ascribed to multivacancies in the As-Se matrix. The superposition of PAL spectrum peaks and tails for pelletized PVP, unmilled, dry-milled, and dry–wet-milled As-Se samples shows a spectacular smoothly decaying trend. The microstructure scenarios of the spontaneous (under quenching) and activated (under nanomilling) decomposition of principal network clusters in As₄Se₂-bearing arsenoselenides are recognized. Over-constrained As_6·(2/3) ring-like network clusters acting as pre-cursors of the rhombohedral As phase are the main products of this decomposition. Two spontaneous processes for creating thioarsenides with crystalline counterparts explain the location of the glass-forming border in an As-Se system near the As₄Se₂ composition, while an activated decomposition process for creating layered As₂Se₃ structures is responsible for the nanomilling-driven molecular-to-network transition. Full article

Indomethacin (IND) as a non-selective cyclooxygenase 1 and 2 inhibitor administered orally causes numerous adverse effects, mostly related to the gastrointestinal tract. Moreover, when applied exogenously in topical preparations, there are obstacles to its permeation through the stratum corneum due to its low water solubility and susceptibility to photodegradation. In this work, solid dispersions (SDs) of IND with low-substituted hydroxypropyl cellulose (LHPC) were developed. The IND—SDs were incorporated into a hydroxypropyl guar (HPG) hydrogel to enhance drug solubility on the skin. The hydrogels were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR), viscosity, drug release, and unspecific cytotoxicity in mammalian cells. SEM showed a highly porous structure for SD hydrogels. DSC and XRPD studies showed that amorphous IND species were formed; therefore, these hydrogels exhibited superior drug release in comparison with IND raw material hydrogels. FTIR evidenced the presence of the hydrogen bond in the SD hydrogel. The rheology parameter viscosity increased across gels formulated with SDs in comparison with hydrogels with pure IND. In addition, IND—SD hydrogels combine the advantages of a suitable viscosity for dermal use and no potentially hazardous skin irritation. This study suggests that the formulated IND—SD hydrogels represent a suitable candidate for topical administration. Full article

Polyamorphic transformations driven by high-energy mechanical ball milling (nanomilling) are recognized in a melt-quenched glassy alloy of tetra-arsenic triselenide (As₄Se₃). We employed XRPD analysis complemented by thermophysical heat-transfer and micro-Raman spectroscopy studies. A straightforward interpretation of the medium-range structural response to milling-driven reamorphization is developed within a modified microcrystalline model by treating diffuse peak-halos in the XRPD patterns of this alloy as a superposition of the Bragg-diffraction contribution from inter-planar correlations, which are supplemented by the Ehrenfest-diffraction contribution from inter-atomic and/or inter-molecular correlations related to derivatives of thioarsenide As₄Se_n molecules, mainly dimorphite-type As₄Se₃ ones. These cage molecules are merely destroyed under milling, facilitating the formation of a polymerized network with enhanced calorimetric heat-transfer responses. Disruption of intermediate-range ordering, due to weakening of the FSDP (the first sharp diffraction peak), accompanied by an enhancement of extended-range ordering, due to fragmentation of structural entities responsible for the SSDP (the second sharp diffraction peak), occurs as an interplay between medium-range structural levels in the reamorphized As₄Se₃ glass alloy. Nanomilling-driven destruction of thioarsenide As₄Se_n molecules followed by incorporation of their remnants into a glassy network is proved by micro-Raman spectroscopy. Microstructure scenarios of the molecular-to-network polyamorphic transformations caused by the decomposition of the As₄Se₃ molecules and their direct destruction under grinding are recognized by an ab initio quantum-chemical cluster-modeling algorithm. Full article

The successful development of an amorphous form of a drug demands the use of process conditions and materials that reduce their thermodynamic instability. For the first time, we have prepared amorphous ibrutinib using the quench-cooling method with very high process efficiency. In the presented study, different formulations of amorphous active pharmaceutical ingredient (API) with Soluplus (SOL) in various weight ratios 1:9, 3:7, and 1:1 were prepared. The obtained samples were stored under long-term (25 ± 2 °C/60%RH ± 5% RH, 12 months) and accelerated (40 ± 2 °C/75%RH ± 5% RH, 6 months) storage conditions. The physical stability of amorphous ibrutinib and ibrutinib–Soluplus formulations was analyzed using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powder X-ray diffraction analysis (XRPD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The lack of significant interactions between the ingredients of the formulation was confirmed by FTIR analysis. An increase in moisture content with an increasing SOL weight ratio was observed under accelerated aging and long-term conditions. Additionally, a slight increase in the moisture content of the stored sample compared to that at the initial time was observed. The results revealed the physical strength of the polymeric systems in the presence of high humidity and temperature. The observed high thermal stability allows the use of various technological processes without the risk of thermal degradation. Full article

In addition to many materials, silver vanadate (AgVO₃) has gained interest due to its antimicrobial properties, which opens up the potential for use as an antibacterial agent for biomedical applications. This work aimed to study the effect of AgVO₃ addition on the structural and morphological properties of a developed dental porcelain (DP) prepared from natural raw materials. AgVO₃ nanowires, prepared by the coprecipitation method, were added in different amounts (1, 3, and 5 wt.%) to a DP mass with the initial composition of 80 wt.% feldspar, 15 wt.% quartz, and 5 wt.% kaolin, obtained by sintering the mixture at 1300 °C. The structural and morphological properties of AgVO₃ and DP were investigated by X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), and transmission electron microscopy (TEM). The results showed the formation of α-AgVO₃ nanowires coated with semispherical metallic silver nanoparticles. Moreover, α-AgVO₃ additions do not influence the structural and morphological properties of DP, with the presence of Ag and V clearly identified in the DP with the α-AgVO₃ addition. Our findings highlight the potential of this novel material for use in various dental applications. Future studies need to establish the antibacterial properties of the prepared dental material. Full article

In the present study, LiFePO₄/CNF self-standing cathodes for LIBs are synthesized by electrospinning. A lower active material amount (12.3 and 34.5 wt%) is used, compared to the conventional tape-casted cathodes (70–85 wt%). The characterization techniques (XRPD, SEM, TEM, EDS, Raman spectroscopy, and thermogravimetry) confirm that the olivine-type structure of LiFePO₄ is maintained in the binder-free electrodes, and the active material is homogeneously dispersed into and within the carbon nanofibers. The electrochemical investigation demonstrates that higher Li⁺ diffusion coefficients (1.36 × 10⁻¹¹ cm²/s) and improved reversibility are reached for free-standing electrodes, compared to the LiFePO₄ tape-casted cathode (80 wt% of active material) appositely prepared for comparison. The 34.5 wt% LiFePO₄ self-standing cathode displays a lower capacity fading, good reversibility and stability, enhanced capacity values at C-rates higher than 5C, and a good lifespan when cycled 1000 cycles at 1C and further cycled up to 20C, compared to the tape-casted counterpart. Notably, the improved electrochemical performances are obtained by only the 34.5 wt% of active material. The results evidence the relevant role of the CNF matrix suitable to host LiFePO₄, to promote electrolyte permeation and contact with the active material, and to increase the electronic conductivity. Full article

Octreotide is the first synthetic peptide hormone, consisting of eight amino acids, that mimics the activity of somatostatin, a natural hormone in the body. During the past decades, advanced instrumentation and crystallographic software have established X-Ray Powder Diffraction (XRPD) as a valuable tool for extracting structural information from biological macromolecules. The latter was demonstrated by the successful structural determination of octreotide at a remarkably high d-spacing resolution (1.87 Å) (PDB code: 6vc1). This study focuses on the response of octreotide to different humidity levels and temperatures, with a particular focus on the stability of the polycrystalline sample. XRPD measurements were accomplished employing an Anton Paar MHC-trans humidity-temperature chamber installed within a laboratory X’Pert Pro diffractometer (Malvern Panalytical). The chamber is employed to control and maintain precise humidity and temperature levels of samples during XRPD data collection. Pawley analysis of the collected data sets revealed that the octreotide polycrystalline sample is remarkably stable, and no structural transitions were observed. The compound retains its orthorhombic symmetry (space group: P2₁2₁2₁, a = 18.57744(4) Å, b = 30.17338(6) Å, c = 39.70590(9) Å, d ~ 2.35 Å). However, a characteristic structural evolution in terms of lattice parameters and volume of the unit cell is reported mainly upon controlled relative humidity variation. In addition, an improvement in the signal-to-noise ratio in the XRPD data under a cycle of dehydration/rehydration is reported. These results underline the importance of considering the impact of environmental factors, such as humidity and temperature, in the context of structure-based drug design, thereby contributing to the development of more effective and stable pharmaceutical products. Full article

Egyptian Faience, a revolutionary innovation in ancient ceramics, was used for crafting various objects, including amulets, vessels, ornaments, and funerary figurines, like shabtis. Despite extensive research, many aspects of ancient shabti production technology, chemistry and mineralogy remain relatively understudied from the 21st to the 22nd Dynasty, belonging to a recovered 19th-century private collection. The fragments’ origin is tentatively identified in the middle Nile valley in the Luxor area. Our study focused on a modest yet compositionally interesting small collection of shabti fragments to provide information on the glaze’s components and shabti’s core. We found that the core is a quartz and K-feldspars silt blended with an organic component made of plastic resins and vegetable fibres soaked with natron. The studied shabti figurines, after being modelled, dried, and covered with coloured glaze, were subjected to a firing process. Sodium metasilicate and sulphate compounds formed upon contact of the glaze with the silica matrix, forming a shell that holds together the fragile inner matrix. The pigments dissolved in the sodic glaze glass, produced by quartz, K-feldspars, and natron frit, are mainly manganese (Mn) and copper (Cu) compounds. The ratio Cu₂O/CaO > 5 produces a blue colour; if <5, the glaze is green. In some cases, Mg and As may have been added to produce a darker brown and an intense blue, respectively. Reaction minerals provided information on the high-temperature firing process that rapidly vitrified the glaze. These data index minerals for the firing temperature of a sodic glaze, reaching up to a maximum of 1050 °C. Full article

Pomegranate peel extract is known for its potent antibacterial, antiviral, antioxidant, anti-inflammatory, wound healing, and probiotic properties, leading to its use in treating oral infections. In the first stage of this work, for the first time, using the Design of Experiment (DoE) approach, pomegranate peel extract (70% methanol, temperature 70 °C, and three cycles per 90 min) was optimized and obtained, which showed optimal antioxidant and anti-inflammatory properties. The optimized extract showed antibacterial activity against oral pathogenic bacteria. The second part of this study focused on optimizing an electrospinning process for a combination of polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) nanofibers loaded with the optimized pomegranate peel extract. The characterization of the nanofibers was confirmed by using SEM pictures, XRPD diffractograms, and IR-ATR spectra. The composition of the nanofibers can control the release; in the case of PVP–based nanofibers, immediate release was achieved within 30 min, while in the case of PCL/PVP, controlled release was completed within 24 h. Analysis of the effect of different scaffold compositions of the obtained electrofibers showed that those based on PCL/PVP had better wound healing potential. The proposed strategy to produce electrospun nanofibers with pomegranate peel extract is the first and innovative approach to better use the synergy of biological action of active compounds present in extracts in a patient-friendly pharmaceutical form, beneficial for treating oral infections. Full article

The NASICON-structured Na₃MnZr(PO₄)₃ compound is a promising high-voltage cathode material for sodium-ion batteries (SIBs). In this study, an easy and scalable electrospinning approach was used to synthesize self-standing cathodes based on Na₃MnZr(PO₄)₃ loaded into carbon nanofibers (CNFs). Different strategies were applied to load the active material. All the employed characterization techniques (X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), thermal gravimetric analysis (TGA), and Raman spectroscopy) confirmed the successful loading. Compared to an appositely prepared tape-cast electrode, Na₃MnZr(PO₄)₃/CNF self-standing cathodes demonstrated an enhanced specific capacity, especially at high C-rates, thanks to the porous conducive carbon nanofiber matrix. Among the strategies applied to load Na₃MnZr(PO₄)₃ into the CNFs, the electrospinning (vertical setting) of the polymeric solution containing pre-synthesized Na₃MnZr(PO₄)₃ powders resulted effective in obtaining the quantitative loading of the active material and a homogeneous distribution through the sheet thickness. Notably, Na₃MnZr(PO₄)₃ aggregates connected to the CNFs, covered their surface, and were also embedded, as demonstrated by TEM and EDS. Compared to the self-standing cathodes prepared with the horizontal setting or dip–drop coating methods, the vertical binder-free electrode exhibited the highest capacity values of 78.2, 55.7, 38.8, 22.2, 16.2, 12.8, 10.3, 9.0, and 8.5 mAh/g at C-rates of 0.05C, 0.1C, 0.2C, 0.5C, 1C, 2C, 5C, 10C, and 20C, respectively, with complete capacity retention at the end of the measurements. It also exhibited a good cycling life, compared to its tape-cast counterpart: it displayed higher capacity retention at 0.2C and 1C, and, after cycling 1000 cycles at 1C, it could be further cycled at 5C, 10C, and 20C. Full article

Non-steroidal anti-inflammatory piroxicam (PRX) is a poorly water-soluble drug that provides relief in different arthritides. Reducing the particle size of PRX increases its bioavailability. For pediatric, geriatric, and dysphagic patients, oral dispersible systems ease administration. Moreover, fast disintegration followed by drug release and absorption through the oral mucosa can induce rapid systemic effects. We aimed to produce an orodispersible lyophilizate (OL) consisting of nanosized PRX. PRX was solved in ethyl acetate and then sonicated into a poloxamer-188 solution to perform spray-ultrasound-assisted solvent diffusion-based nanoprecipitation. The solid form was formulated via freeze drying in blister sockets. Mannitol and sodium alginate were applied as excipients. Dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) were used to determine the particle size. The morphology was characterized by scanning electron microscopy (SEM). To establish the crystallinity, X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) were used. A disintegration and in vitro dissolution test were performed. DLS and NTA presented a nanosized PRX diameter. The SEM pictures showed a porous structure. PRX became amorphous according to the XRPD and DSC curves. The disintegration time was less than 1 min and the dissolution profile improved. The final product was an innovative anti-inflammatory drug delivery system. Full article