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The permeation liquid membrane (PLM) technique was used to evaluate cadmium speciation in media resembling natural freshwaters. A planar sheet PLM system was characterized by measuring Cd fluxes in the absence and presence of complexing agents such as citrate, malonate, nitrilotriacetate and the Suwannee River standard humic acid. Comparison with theoretical speciation calculations and the results of a Cd2+ selective electrode, showed that free Cd was correctly measured using the planar sheet PLM within the studied concentration range, i.e. 10(-8) to 10(-4) M. The effect of pH and potentially co-transported ions on Cd transport through the PLM was also studied. An example of the ability of the hollow-fiber PLM (HFPLM) to measure free Cd in the nM range is also presented. In order to evaluate the usefulness of the technique as a predictor of bioavailability, Cd PLM measurements (fluxes) were compared to Cd biouptake (internalization flux) for a freshwater alga, Chlorella kesslerii, in the absence and presence of SRHA. The use of PLM measurements is shown to be an attractive tool to better understand Cd biouptake.
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http://dx.doi.org/10.1016/j.aca.2006.05.096 | DOI Listing |
Int J Biol Macromol
September 2025
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, PR China. Electronic address:
Due to the poor regeneration ability of cartilage tissue, the design and fabrication of permanent hydrogel cartilage scaffolds with mechanical properties matching is still an urgent challenge. In this study, we propose an "inner swelling-outer restraint" strategy to construct Janus hydrogel for pressure-bearing cartilage replacement, which is inspired by the "Lamina-splendens" structure of cartilage. As a proof of concept, the poly(vinyl alcohol)/carboxymethyl cellulose sodium (PVA/CMCNa) layer is designed to capture more fluid by introducing negatively charged aggregates, while the macromolecular conformation of the PVA/MoS layer can be densified through wet annealing, thereby increasing the liquid permeation resistance of the PVA/CMCNa layer.
View Article and Find Full Text PDFInt J Biol Macromol
September 2025
Department of Materials Science, Institute of Graduate Studies and Research, Alexandria University, Alexandria 21526, Egypt. Electronic address:
Desalination has emerged as a key solution to the growing global demand for clean water. Membrane distillation (MD) has gained increasing attention due to its ability to treat hypersaline and complex wastewater using low-grade thermal energy. However, MD membranes continue to face performance challenges, particularly low permeate flux and limited resistance to pore wetting.
View Article and Find Full Text PDFPharmaceuticals (Basel)
August 2025
Department of Biosciences, Piracicaba Dental School, Universidade Estadual de Campinas, Av. Limeira, 901, Piracicaba 13414-903, SP, Brazil.
Local anesthesia is essential for most dental procedures, but its parenteral administration is often painful. Topical anesthetics are commonly used to minimize local anesthesia pain; however, commercial formulations fail to fully prevent the discomfort of local anesthetic injection. We developed and characterized a novel lidocaine and epinephrine co-loaded liquid crystalline precursor system (LCPS) for topical anesthesia.
View Article and Find Full Text PDFSci Adv
August 2025
Department of Mechanical Engineering, State Key Laboratory of Tribology in Advanced Equipment, Tsinghua University, Beijing 100084, China.
Carbon nanomaterials exhibit unique electrokinetic phenomena due to rapid ion transport within the Debye layer, which have been exploited for energy conversion, membrane technology, and liquid lubrication. The electronic properties of solids have been found to influence water permeation and proton transport; however, their effect on ion transport has not been observed. Here, we present an experimental investigation of ion transport in individual double-walled carbon nanotubes (CNTs) of both semiconducting and metallic nature.
View Article and Find Full Text PDFLab Chip
August 2025
Univ. Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France.
Controlling the removal of bubbles from channels is crucial in microfluidics, either to eliminate air pockets if they are unwanted, or in pumpless microfluidic applications where receding bubbles is a way to induce liquid flows. To provide a better physical understanding of air removal in microchannels, we study the dynamics of invasion of wetting liquids in dead-end microchannels surrounded by an air-permeable medium. Using polydimethylsiloxane (PDMS)-based devices, we demonstrate that gas permeation through the channel walls drives an exponential decay in trapped air length with time (in marked contrast with the so-called Lucas-Washburn law of imbibition in porous media), providing a straightforward route to bubble elimination.
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