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Molecular crystals with water molecules in the crystal lattice (hydrates) can radically change properties if dehydrated. The two most practically relevant pathways of dehydration can be classified as either thermally-induced or solvent-induced. The solid form transformations occurring during these processes are taking place at the surface of the particles either in the solid–gas or solid–liquid interface. In this study, it is demonstrated how atomic force microscopy (AFM) can be used to measure topography, elastic modulus and work function to elucidate differences at the crystal surface depending on the dehydration pathway. These results are performed at a single particle level, so it would be important to link the findings to the bulk powder behaviour. To address this, static charging measurements for bulk powder samples were compared with the single crystal surface measurements. The thermally-induced anhydrate acquired more charge than the monohydrate at the bulk level which could be explained by the increase in work function and surface roughness at a single particle level. The change in sign for the solvent-induced anhydrate was also in agreement with the work function. This underpins the importance of also considering microscale properties, when characterizing nanoscale structures at the surface of particulate systems. [ABSTRACT FROM AUTHOR]

In this study, the antibacterial efficacy of NO-releasing porous silicon nanoparticles (pSiNPs) is reported. NO-releasing pSiNPs were produced via the conjugation of S-nitrosothiol (SNO) and S-nitrosoglutathione (GSNO) donors to the nanoparticle surfaces. The release of the conjugated NO caused by the decomposition of the conjugated SNO and GSNO was boosted in the presence of ascorbic acid. The released NO was bactericidal to Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli), and eliminated bacterial growth within 2 h of incubation without compromising the viability of mammalian cells. These results demonstrate the advantages of NO-releasing pSiNPs for antibacterial applications, for example, in chronic wound treatment. [ABSTRACT FROM AUTHOR]

Evaporation rates play a key role in evaporation crystallization and the drying of crystal products. Raman analysis was used to study the effect of the evaporation rate on the polymorphs of indomethacin at room temperature. The studied solvents were highly volatile ethanol, acetone, and ethyl acetate. The approach was based on a mass transfer model of evaporation, and experimental flux measurements were used for model evaluation. Evaporation rates from porous carriers were also investigated. The studied mesoporous silicon microparticles can be used in oral dosage forms of poorly soluble active pharmaceutical ingredients. Evaporation rates of dimethyl sulfoxide from a pure solvent, from indomethacin solutions, and from solutions containing microparticles were measured at 100 °C. An evaporation rate model of porous particles was used and the predicted results were compared with the experimental results obtained. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess longitudinally the success of partial and full crown abutment pairs in the same bridges. Fifty patients with a mean age of 45 years (range 22-70 years) were examined during spring 1981 (1-5 year follow-up), 33 of whom were examined a second time during spring 1990 (10-15 year follow-up). The status of the partial crowns, full crowns, and their abutment teeth was assessed using standardized questions, and clinical and radiographic examinations. At the first follow-up examination, all partial and full crowns, and consequently all bridges, were still in use. Before the second follow-up examination one of the full crown abutments had become badly decayed, and the bridge, including the partial crown, had been removed. The failure rate was 0.2% per year for the full crown as a unit, and consequently 0.2% per year for the bridge as a unit. [ABSTRACT FROM AUTHOR]

Radiographic signs in the temporomandibular joints (TMJs) and finger Joints were investigated in a series of 1)9 residents of elderly people's homes using panoramic tomographs and dorso-volar radiographs. Radiographic signs in TMJs were found in 14% of the subjects, whereas all subjects had signs In at least one finger Joint. The TMJs of men and women were equally affected, whereas signs in finger joints were more severe in women. No correlation was found between radiographic signs In TMJs and finger joints, suggesting that most signs in TMJs are probably due to local factors. [ABSTRACT FROM AUTHOR]