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The Study of the Effect of UV-C Radiation on the Current–Voltage Characteristics of Chitosan Membranes
Published in Pandit B. Vidyasagar, Sagar S. Jagtap, Omprakash Yemul, Radiation in Medicine and Biology, 2017
Ni Nyoman Rupiasih, Made Sumadiyasa, Putu Erika Winasri
The numerous membranes have been developed for use in reverse osmosis, nanofiltration, ultrafiltration, microfiltration, pervaporation separation, and electrodialysis and in medical use such as artificial kidney [6]. Among these membranes, ion-exchange membranes are one of the advanced separation membranes. It has been used not only as electrodialysis concentration or desalting of solutions, diffusion dialysis to recover acids and electrolysis of sodium chloride solution but also in various fields as a polymeric film having ionic groups [7].
Drinking water treatment *
Published in Jamie Bartram, Rachel Baum, Peter A. Coclanis, David M. Gute, David Kay, Stéphanie McFadyen, Katherine Pond, William Robertson, Michael J. Rouse, Routledge Handbook of Water and Health, 2015
A more advanced method of filtration is provided by one of the different membrane technologies. Membranes come in a variety of types described on the basis of the pore size. Pore size is the spaces in the material which sieve out the particles or substances of concern and so membrane filtration does rely on size exclusion rather than physico-chemical forces to achieve separation of the solid and liquid phases. There are various degrees of size exclusion of particle removal which range from microfiltration (nominal pore sizes in the range 10 microns to 0.03 microns) through ultrafiltration (nominal pore sizes between 0.1 and 0.002 microns) to nanofiltration (nominal pore size 0.001 microns) and reverse osmosis which is capable of removing nearly all inorganic (and organic) contaminants from water. Generally, the water must be further treated to add minerals and to ensure that the water is adequately buffered after reverse osmosis treatment.
Biologic Drug Substance and Drug Product Manufacture
Published in Anthony J. Hickey, Sandro R.P. da Rocha, Pharmaceutical Inhalation Aerosol Technology, 2019
Ajit S. Narang, Mary E. Krause, Shelly Pizarro, Joon Chong Yee
In this step, the cell culture harvest, consisting of target protein in the dissolved state and suspended solids such as cells and cell debris, is subjected to sedimentation, centrifugation, deep bed or depth filtration, and one or more steps of microfiltration. Sedimentation and centrifugation: Gravitational and centrifugal rotational settling of particulate matter allows initial separation of most of the particles from the fluid for initial clarification.Depth filtration or deep bed filtration consists of a porous filtration medium that retains particles throughout the medium, rather than just on the surface. This process is particularly suitable for fluids with high particle load since the filter can retain a large mass of particles before getting clogged. Depth filters provide high surface area and adsorptive surface. In addition to adsorbing impurities from cell culture supernatants, depth filters can also remove viruses (Yigzaw et al. 2006).Microfiltration involves passing the fluid through a specific pore size membrane to effect removal of microorganisms and suspended particles. Suspended particles are retained (“retentate”) on the feed side of the membrane, while the dissolved liquids, including the protein of interest, passes through (“permeate”). A cross-flow filtration process, where the fluid is moved in a direction tangential to the membrane surface, is preferred compared to the dead-end filtration (where the fluid is forced through the membrane surface at a dead end to the direction of flow).
Antimicrobial effectiveness of root canal sealers against Enterococcus faecalis
Published in Biomaterial Investigations in Dentistry, 2022
Paola Castillo-Villagomez, Elizabeth Madla-Cruz, Fanny Lopez-Martinez, Idalia Rodriguez-Delgado, Jorge Jaime Flores-Treviño, Guadalupe Ismael Malagon-Santiago, Myriam Angelica de La Garza-Ramos
Complete removal of microorganisms from the root canal system in all patients is impossible; therefore, filling materials with antimicrobial activity for the root canal are used to reduce microorganisms and prevent infections. On the other hand, many endodontic failures occur after removing necrotic or inflammatory tissue with microorganisms. These tissues need to be retreated and managed with apical surgery; however, filtration failure occurs in 15% to 22% [4]. These complications are attributed to the lack of root canal sealing after endodontic treatment due to the high hydrophobicity and water absorption caused by the solubility of the cement. The development of new ceramic-type materials has improved sealing to reduce this problem. Epoxy resin is widely used as a gold standard, although it still has limitations, such as mutagenicity, cytotoxicity, inflammation, and hydrophobicity. Calcium silicate-based sealers with high biocompatibility and hydrophilicity have also been introduced. Both cements reduce microfiltration thanks to properties in their dynamic environment and being biocompatible in this application [5].
Hepatoprotective effects of Camellia nitidissima aqueous ethanol extract against CCl4-induced acute liver injury in SD rats related to Nrf2 and NF-κB signalling
Published in Pharmaceutical Biology, 2020
Xiaoman Zhang, Jie Feng, Shaofeng Su, Lei Huang
The CNE was diluted with methanol/water (50%, v/v), then applied to a solid phase extraction column. Next, the solvent was removed using a rotary evaporator and the sample dissolved with acetonitrile/water (50%, v/v). Finally, the sample was filtered through a microfiltration membrane for analysis. The Thermo Fisher UHPLC procedure was used to analyse the sample on a 2.1 × 100 mm, 1.7 μm bead size C18 column (Waters, Milford, MA). The mobile phase consisted of solvent A, acetonitrile and solvent B, 0.1% formic acid in deionized H2O. Binary gradient elution was performed: 0–2 min, 5% A; 2–16 min, 5–95% A; 16–18 min, 95% A. MS analysis was carried out using a Q-Exactive mass spectrometer (Thermo Fisher Scientific) and an electrospray ionization (ESI) source. The analysis was performed using full scan mode, and the mass range was set at m/z 100–1000 in both the positive and negative ion modes. Data acquisition and processing were carried out using Xcalibur software (Thermo Fisher Scientific).
On-line biofilm strength detection in cross-flow membrane filtration systems
Published in Biofouling, 2018
Stanislaus Raditya Suwarno, Wenhai Huang, Y. M. John Chew, Sio Hoong Henrich Tan, Augustinus Elmer Trisno, Yan Zhou
Both the cohesive and adhesive strengths obtained from biofilms in the present study are considerably higher than those from other FDG studies (Möhle et al. 2007; Lewis et al. 2012). Möhle et al. (2007) used FDG to investigate the activated sludge forming biofilm grown on a rotating disc biofilm reactor (rotation speed of <9 min−1 for seven days) and found the cohesive strength of the biofilm was only 6–7 N m−2. Lewis et al. (2012) applied a cross-flow system and formed biofilm by an yeast suspension. Their experiment was conducted for 30 min with a duct flow rate of 0.9 l min−1 under a constant TMP of 3.5 kPa. The highest strength of biofilm was ~55 N m−2. In the present study, the operating conditions applied were harsher and simulated the actual conditions of microfiltration for water treatment. Moreover biofilms formed by Pseudomonas aeruginosa tend to have higher strength as evidenced by other ex situ methods (6,000–15,000 N m−2) (Korstgens et al. 2001; Poppele and Hozalski 2003).