A novel, rugged capillary electrophoresis-electrospray ionization (CE-ESI) interface where the separation column, an electrical porous junction, and the spray tip are integrated on a single piece of a fused-silica capillary is described. ESI is accomplished by applying an electrical potential through an easily prepared porous junction across a 3-4-mm length of fused silica. A stable electrospray is produced at nanoflow rates generated in the capillary by electrophoretic and electroosmotic forces. The interface is particularly well suited for the detection of low-femtomole levels of proteins and peptides. The ruggedness of this interface was evident by the continuous operation of the same column for over a 2-week period with no detectable deterioration in separation or electrospray performance. The new interface was used for the LC-ESI-MS separation and analysis of peptides and proteins. Injection of 25 fmol of [Glu1]-fibrinopeptide B using the new device produced a CE-ESI-MS electropherogram with a signal-to-noise ratio of over 100 for this peptide.
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http://dx.doi.org/10.1021/ac020661+ | DOI Listing |
Micromachines (Basel)
December 2024
Department of Mechanical Engineering, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
The placenta plays a critical role in nutrient and oxygen exchange during pregnancy, yet the effects of medicinal drugs on this selective barrier remain poorly understood. To overcome this, this study presents a cost-effective bioimpedance spectroscopy (BIS) system to assess tight junction integrity and monolayer formation in BeWo b30 cells, a widely used model of the multinucleated maternal-fetal exchange surface of the placental barrier. Cells were cultured on collagen-coated porous membranes and treated with forskolin to induce controlled syncytialization.
View Article and Find Full Text PDFBiomedicines
December 2024
Department of Molecular Cell Biology and Immunology, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
: The barrier properties of the human small intestine play a crucial role in regulating digestion, nutrient absorption and drug metabolism. Current in vitro organotypic models consist only of an epithelium, which does not take into account the possible role of stromal cells such as fibroblasts or the extracellular matrix (ECM) which could contribute to epithelial barrier properties. Therefore, the aim of this study was to determine whether these stromal cells or ECM were beneficial or detrimental to barrier function when incorporated into an organotypic human small intestine model.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Portici Research Centre, P.le E. Fermi 1, Portici, 80055 Naples, Italy.
In recent years, the morphology control of semiconductor nanomaterials has been attracting increasing attention toward maximizing their functional properties and reaching their end use in real-world devices. However, the development of easy and cost-effective methods for preparing large-scale patterned semiconductor structures on flexible temperature-sensitive substrates remains ever in demand. In this study, vapor post-treatment (VPT) is investigated as a potential, simple and low-cost post-preparative method to morphologically modify gravure-printed zinc oxide (ZnO) nanoparticulate thin films at low temperatures.
View Article and Find Full Text PDFEur Phys J E Soft Matter
December 2024
School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
Although immiscible displacement in porous media has been extensively studied, a more comprehensive analysis of the underlying dynamic behaviors is still necessary. In this work, we conducted experimental and theoretical analyses on the dynamic interplay among channels during immiscible displacement under varying flow rates. In a rock-structured microfluidic chip, we observed typical displacement patterns, including viscous fingering and capillary fingering, and analyzed their frontiers and efficiencies.
View Article and Find Full Text PDFPolymers (Basel)
November 2024
Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, University of Belgrade, Mike Petrovića Alasa 12-14, Vinča, 11351 Belgrade, Serbia.
Today, hydrogel dressings that can protect injury sites and effectively promote healing have become highly desirable in wound management. Therefore, multifunctional silver-poli(-isopropylacrylamide/itaconic acid) (Ag-P(NiPAAm/IA)) hydrogel nanocomposites were developed for potential application as topical treatment dressings. The radiolytic method, used for the crosslinking of the polymer matrix as well as for the in situ incorporation of silver nanoparticles (AgNPs) into the polymer matrix, enables the preparation of hydrogel nanocomposites without introducing harmful and toxic agents.
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