The fractionation of natural nanoparticles by Asymmetrical Flow Field Flow Fractionation (As-Fl-FFF) was optimised by considering the following operating conditions: ionic strength, surfactant concentration and crossflow rate. The method performances such as fractionation recovery and fractionation efficiency were evaluated on a stable solution of colloidal-size natural inorganic particles. The online multi-detection by ultraviolet/visible spectrophotometer (UV) and multi-angle laser light scattering (MALLS) provided the monitoring of the sample during the separation and the evaluation of the fractionation efficiency. The lowest ionic strength and surfactant concentrations (i.e. 10(-3) mol L(-1) NH4NO3 and 3 x 10(-4) mol L(-1) SDS) allowed to obtain the highest sample recovery and lowest loss of the largest particles. The crossflow rate was investigated in order to avoid significant membrane-sample interaction. The applicability of the fractionation in optimised conditions was evaluated on a natural soil leachate, which was filtrated with different filter cut-offs. Filtration efficiency was stressed by the decrease of the large unfractionated particle influence in the void volume. For the first time, robust operating conditions were proposed to well size-fractionate and characterize soil nanoparticles within a single multi-detection analysis.
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http://dx.doi.org/10.1016/j.chroma.2008.07.032 | DOI Listing |
Pulmonology
December 2025
Alma Mater Studiorum, Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy.
Nasal high flow (NHF) therapy is an established form of non invasive respiratory support used in acute and chronic care. Recently, a new high flow nasal cannula with asymmetric prongs was approved for clinical use. The clinical benefits of the new cannula have not yet been defined and no evidence are available on the use of asymmetric NHF support in patient with Chronic Obstructive Pulmonary Disease (COPD).
View Article and Find Full Text PDFMol Biol Evol
January 2025
UMR 8222 LECOB CNRS-Sorbonne Université, Observatoire Océanologique de Banyuls, Avenue du Fontaulé, 66650, Banyuls-sur-mer, France.
How the interplay of biotic and abiotic factors shapes current genetic diversity at the community level remains an open question, particularly in the deep sea. Comparative phylogeography of multiple species can reveal the influence of past climatic events, geographic barriers, and species life history traits on spatial patterns of genetic structure across lineages. To shed light on the factors that shape community-level genetic variation and to improve our understanding of deep-sea biogeographic patterns, we conducted a comparative population genomics study on seven hydrothermal vent species co-distributed in the Back-Arc Basins (BABs) of the Southwest Pacific region.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
Waters Corporation, Instrument/Core Research/Fundamental, Milford, MA, 01757, USA. Electronic address:
Significant progress has been made in the last two decades in producing small (<2μm), high-purity, and low-adsorption particles, columns and system hardware, for ultra-high pressure liquid chromatography (UHPLC). Simultaneously, the recent rapid expansion of cell and gene therapies for treating diseases necessitates novel analytical technologies for analyzing large (>2 kbp) plasmid double-stranded (ds) DNA (which encodes for the in vitro transcription (IVT) of single-stranded (ss) mRNA therapeutics) and dsRNAs (related to IVT production impurities) biopolymers. In this context, slalom chromatography (SC), a retention mode co-discovered in 1988, is being revitalized using the most advanced column technologies for improved determination of the critical quality attributes (CQAs) of such new therapeutics.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
Office of Pharmaceutical Quality Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, USA. Electronic address:
Asymmetrical flow field-flow fractionation (AF4) with multi-detection has continued to gain wider acceptance for characterizing complex drug products. An important quality attribute for these products is the measurement of the particle size distribution (PSD). Current limitations of established procedures (e.
View Article and Find Full Text PDFNat Commun
January 2025
Engineering Center of Catalysis and Synthesis for Chiral Molecules, Department of Chemistry, Fudan University, Shanghai, 200433, China.
Flow chemistry has many advantages over batch synthesis of organic small-molecules in terms of environmental compatibility, safety and synthetic efficiency when scale-up is considered. Herein, we report the 10-step chemo-biocatalytic continuous flow asymmetric synthesis of cyproterone acetate (4) in which 10 transformations are combined into a telescoped flow linear sequence from commercially available 4-androstene-3, 17-dione (11). This integrated one-flow synthesis features an engineered 3-ketosteroid-Δ-dehydrogenase (ReM2)-catalyzed Δ-dehydrogenation to form the C1, C2-double bond of A ring, a substrate-controlled Co-catalyzed Mukaiyama hydration of 9 to forge the crucial chiral C17α-OH group of D ring with excellent stereoselectivity, and a rapid flow Corey-Chaykovsky cyclopropanation of 7 to build the cyclopropyl core of A ring.
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