The role of membrane surface charge and solute physico-chemical properties in the rejection of organic acids by NF membranes

2005 ◽  
Vol 249 (1-2) ◽  
pp. 227-234 ◽  
Author(s):  
Christopher Bellona ◽  
Jörg E. Drewes
Keyword(s):  
Organic Acids ◽  
Surface Charge ◽  
Membrane Surface ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Membrane Surface Charge

scholarly journals Occurrence of drug target residues within decantation tank sediments: a good clue to assess their historical excretion?

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Thomas Thiebault ◽  
Laëtitia Fougère ◽  
Anaëlle Simonneau ◽  
Emilie Destandau ◽  
Claude Le Milbeau ◽  
...  
Keyword(s):  
Drug Target ◽  
Chemical Properties ◽  
Deposition Process ◽  
Drug Consumption ◽  
Organic Layers ◽  
Sewer Systems ◽  
Physico Chemical ◽  
Deep Underground ◽  
Deposition Processes

AbstractThis study investigated the potential of sediments accumulated in sewer systems to record human activities through the occurrence of drug target residues (DTR). The installation studied is 17 m deep underground decantation tank that traps the coarse fractions of a unitary sewer system (northern part of Orléans, France), collecting both stormwater and wastewater. The sediments deposited in this tank could constitute a nonesuch opportunity to study the historical evolution of illicit and licit drug consumption in the catchment, however, the deposition processes and the record of DTRs remain largely unknown at present. Five cores were acquired from 2015 to 2017. One hundred fifty-two sediment samples were extracted using a mixture of ultra-pure water:methanol (1:1) prior to analysis of the extracts by high-pressure liquid chromatography coupled to tandem mass spectrometry. Several classical sedimentological analyses such as total organic carbon, facies description and granulometry were also performed on these samples, in order to understand the most important factors (e.g., physico-chemical properties of the DTRs, solid type, assumed load in wastewater) impacting their deposition.The key role of the speciation of DTRs was highlighted by the higher contents in neutral and anionic DTRs in organic layers, whereas only cationic DTRs were found in mineral layers. The considerable modifications in the sediments’ properties, generated by distinct origins (i.e., stormwater or wastewater), are therefore the most important drivers that must be taken into account when back-calculating the historical patterns of drug consumption from their DTR concentrations in decantation tank sediments. Further research remains necessary to fully understand the deposition process, but this study provides new clues explaining these temporal evolutions.

scholarly journals Impact of Quantum Dot Surface on Complex Formation with Chlorin e6 and Photodynamic Therapy

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
Artiom Skripka ◽  
Dominyka Dapkute ◽  
Jurga Valanciunaite ◽  
Vitalijus Karabanovas ◽  
Ricardas Rotomskis
Keyword(s):  
Photodynamic Therapy ◽  
Cancer Therapy ◽  
Complex Formation ◽  
Chemical Properties ◽  
Disease Diagnosis ◽  
Chlorin E6 ◽  
Deep Tissue ◽  
Physico Chemical

Nanomaterials have permeated various fields of scientific research, including that of biomedicine, as alternatives for disease diagnosis and therapy. Among different structures, quantum dots (QDs) have distinctive physico-chemical properties sought after in cancer research and eradication. Within the context of cancer therapy, QDs serve the role of transporters and energy donors to photodynamic therapy (PDT) drugs, extending the applicability and efficiency of classic PDT. In contrast to conventional PDT agents, QDs’ surface can be designed to promote cellular targeting and internalization, while their spectral properties enable better light harvesting and deep-tissue use. Here, we investigate the possibility of complex formation between different amphiphilic coating bearing QDs and photosensitizer chlorin e6 (Ce6). We show that complex formation dynamics are dependent on the type of coating—phospholipids or amphiphilic polymers—as well as on the surface charge of QDs. Förster’s resonant energy transfer occurred in every complex studied, confirming the possibility of indirect Ce6 excitation. Nonetheless, in vitro PDT activity was restricted only to negative charge bearing QD-Ce6 complexes, correlating with better accumulation in cancer cells. Overall, these findings help to better design such and similar complexes, as gained insights can be straightforwardly translated to other types of nanostructures—expanding the palette of possible therapeutic agents for cancer therapy.

Impact of ion exchange membrane surface charge and hydrophobicity on electroconvection at underlimiting and overlimiting currents

2017 ◽  
Vol 523 ◽  
pp. 36-44 ◽  
Author(s):  
K.A. Nebavskaya ◽  
V.V. Sarapulova ◽  
K.G. Sabbatovskiy ◽  
V.D. Sobolev ◽  
N.D. Pismenskaya ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Surface Charge ◽  
Membrane Surface ◽  
Ion Exchange Membrane ◽  
Exchange Membrane ◽  
Membrane Surface Charge
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