A multivariate TOF-SIMS methodology has been developed and applied to quantify surface composition and chemical distribution for dry powder blends. Surface properties are often critical to the behavior of powder formulations, especially in the case of dry powders for inhalation, as surface properties directly affect inter-particulate forces and, hence, the dispersibility of the formulation. The mass spectrum at each pixel was fit to a linear combination of reference spectra obtained by non-negatively constrained alternating least squares. From the pixel compositions, average surface coverage and a range of other image features were calculated. Two kinds of systems have been examined: 1) binary blends of lactose particles and coating agents, and 2) blends of different inhalation drugs with carrier lactose. For both kinds of systems, detailed insight into the surface composition and structure could be derived. For the former study, TOF-SIMS results were compared with a complementary surface analysis technique, XPS.
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http://dx.doi.org/10.1016/j.ijpharm.2020.119666 | DOI Listing |
Nanotechnology
January 2025
Institute of Nonlinear Optics, College of Science, JiuJiang University, Jiangxi 334000, People's Republic of China.
Titanium disulfide quantum dots (TiSQDs) has garnered significant research interest due to its distinctive electronic and optical properties. However, the effectiveness of TiSQDs in electromagnetic interference (EMI) shielding is influenced by various factors, including their size, morphology, monodispersity, tunable bandgap, Stokes shift and interfacial effects. In this study, we propose a systematic approach for the synthesis of TiSQDs with small size (3.
View Article and Find Full Text PDFFront Microbiol
December 2024
Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States.
Microbial activity in the deep continental subsurface is difficult to measure due to low cell densities, low energy fluxes, cryptic elemental cycles and enigmatic metabolisms. Nonetheless, direct access to rare sample sites and sensitive laboratory measurements can be used to better understand the variables that govern microbial life underground. In this study, we sampled fluids from six boreholes at depths ranging from 244 m to 1,478 m below ground at the Sanford Underground Research Facility (SURF), a former goldmine in South Dakota, United States.
View Article and Find Full Text PDFFront Nutr
December 2024
State Key Laboratory of Functions and Applications of Medicinal Plants and School of Pharmaceutical Sciences, Guizhou Medical University, Guiyang, China.
Background: Tratt pomace (RRTP) contains valuable components like polyphenols and polysaccharides, which have high utilization value. Fermentation is an effective technique for creating beneficial nutrients that can improve the taste, appearance, and nutritional benefits of foods. Nevertheless, there is a lack of research on the alterations in chemical composition of RRTP during fermentation.
View Article and Find Full Text PDFOsteoarthritis, a major global cause of pain and disability, is driven by the irreversible degradation of hyaline cartilage in joints. Cartilage tissue engineering presents a promising therapeutic avenue, but success hinges on replicating the native physiological environment to guide cellular behavior and generate tissue constructs that mimic natural cartilage. Although electrical stimulation has been shown to enhance chondrogenesis and extracellular matrix production in 2D cultures, the mechanisms underlying these effects remain poorly understood, particularly in 3D models.
View Article and Find Full Text PDFUnlabelled: Cytoplasmic proteins must recruit to membranes to function in processes such as endocytosis and cell division. Many of these proteins recognize not only the chemical structure of the membrane lipids, but the curvature of the surface, binding more strongly to more highly curved surfaces, or 'curvature sensing'. Curvature sensing by amphipathic helices is known to vary with membrane bending rigidity, but changes to lipid composition can simultaneously alter membrane thickness, spontaneous curvature, and leaflet symmetry, thus far preventing a systematic characterization of lipid composition on such curvature sensing through either experiment or simulation.
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