Numerical Ways to Characterize the Deterioration of Nanofiltration Membranes

In this study, a transport model is used to characterize structural and physico-chemical changes in a nanofiltration membrane during the filtration of ionic mixtures. The membrane state is analyzed by a set of four model parameters identified from glucose and salts filtration: the membrane water permeability (Lp), the mean pore radius (rp), the membrane charge density (Xd), and the dielectric constant of the solution inside pores (ep). The study of these structural and physico-chemical properties allows us to determine if deterioration or fouling occurred during filtration. Two distinct identification procedures from filtration of synthetic solutions are investigated in this paper. One is based on the filtration of single salt solutions, whereas the other lies in parameters identification from mixtures containing at least three ions. These methods are applied here to characterize influence of fouling deposit formation and membrane cleaning

A Cross-Sectional Study of Treatments for Behavioral Disorders Following Traumatic Brain Injury: Comparison With French Recommendations

OBJECTIVE: To give a cross-sectional overview of ongoing management of behavioral disorders following traumatic brain injury (TBI) in a region of France, to compare this with recent recommendations from the French Society of Physical Medicine and Rehabilitation (SOFMER), and to evaluate associations between treatments and participant characteristics. SETTING: Outpatients referred to medical or community-based facilities in a region of France. PARTICIPANTS: One hundred twenty-nine adults with moderate to severe TBI, in the postacute period (over 3 months postinjury). DESIGN: Cross-sectional cohort study. MAIN MEASURES: Sociodemographic data, ongoing interventions including psychotherapy and medication, behavioral disorders assessed by the Behavioral Dysexecutive Syndrome Inventory (BDSI). RESULTS: Thirty-three percent of participants received ongoing psychotherapy and 43% were on medication. The most prescribed medications were antidepressants (21%), neuroleptics (18%), anxiolytics (16%), and mood stabilizers (14%). Eighty-five participants (71%) presented a current Behavioral Dysexecutive Syndrome (BDS) according to the BDSI. These participants more frequently received treatment (P = .004), psychotherapy (P = .048), medications (often 2 or more) (P = .007), and particularly antiepileptic mood stabilizers (P = .037) compared with those without BDS. CONCLUSION: Although recommended as first-line treatment, few participants with BDS received psychotherapy. Medications were overused, especially neuroleptics in view of their potential adverse effects. In contrast, recommended medications, such as mood stabilizers and β-blockers, did not appear to be highly prescribed whatever the evolution. Compliance with recommendations seemed insufficient

The Importance of the Stem Cell Marker Prominin-1/CD133 in the Uptake of Transferrin and in Iron Metabolism in Human Colon Cancer Caco-2 Cells

As the pentaspan stem cell marker CD133 was shown to bind cholesterol and to localize in plasma membrane protrusions, we investigated a possible function for CD133 in endocytosis. Using the CD133 siRNA knockdown strategy and non-differentiated human colon cancer Caco-2 cells that constitutively over-expressed CD133, we provide for the first time direct evidence for a role of CD133 in the intracellular accumulation of fluorescently labeled extracellular compounds. Assessed using AC133 monoclonal antibody, CD133 knockdown was shown to improve Alexa488-transferrin (Tf) uptake in Caco-2 cells but had no impact on FITC-dextran or FITC-cholera-toxin. Absence of effect of the CD133 knockdown on Tf recycling established a role for CD133 in inhibiting Tf endocytosis rather than in stimulating Tf exocytosis. Use of previously identified inhibitors of known endocytic pathways and the positive impact of CD133 knockdown on cellular uptake of clathrin-endocytosed synthetic lipid nanocapsules supported that CD133 impact on endocytosis was primarily ascribed to the clathrin pathway. Also, cholesterol extraction with methyl-β-cyclodextrine up regulated Tf uptake at greater intensity in the CD133high situation than in the CD133low situation, thus suggesting a role for cholesterol in the inhibitory effect of CD133 on endocytosis. Interestingly, cell treatment with the AC133 antibody down regulated Tf uptake, thus demonstrating that direct extracellular binding to CD133 could affect endocytosis. Moreover, flow cytometry and confocal microscopy established that down regulation of CD133 improved the accessibility to the TfR from the extracellular space, providing a mechanism by which CD133 inhibited Tf uptake. As Tf is involved in supplying iron to the cell, effects of iron supplementation and deprivation on CD133/AC133 expression were investigated. Both demonstrated a dose-dependent down regulation here discussed to the light of transcriptional and post-transciptional effects. Taken together, these data extend our knowledge of the function of CD133 and underline the interest of further exploring the CD133-Tf-iron network

Transfer of ionic solutes through nanofiltration membranes: A model combining concentration polarization layer and pores transport

International audienc

Transfer of ionic solutes through nanofiltration membranes: A model combining concentration polarization layer and pores transport

International audienc

Transport of salt mixtures through nanofiltration membranes: identification of electric and dielectric contributions

International audienc

Transfer of charged molecules through nanofiltration membranes: a model combining transport through pores and polarization layer

International audienc

Transfer of ionic solutes through nanofiltration membranes : a model combining polarization layer and pores transport

International audienc