Walkerton
Jamie Bartram, Rachel Baum, Peter A. Coclanis, David M. Gute, David Kay, Stéphanie McFadyen, Katherine Pond, William Robertson, Michael J. Rouse in Routledge Handbook of Water and Health, 2015
On the morning of Wednesday, May 17, the lab phoned the general manager to advise him that all of the construction project samples and the distribution system samples were positive for total coliforms and E. coli by a presence / absence test. Only the well #7 treated sample was analyzed by the membrane filtration procedure allowing determination of microbial counts. Both total coliforms and E. coli produced overgrown plates meaning numbers greater than 200 CFU (colony forming unit) per 100 mL. The inquiry concluded that, based on several lines of evidence, this sample was mis-labeled and was actually taken at well #5. Because the PUC was now using a new commercial lab (its previous lab had stopped doing microbial analysis for them by the end of April, 2000), the new lab did not follow the voluntary convention of the previous lab of notifying the MOE and local medical officer of health about any adverse microbiological samples for drinking water systems. The commercial lab did fax these results to the PUC office. The first fax on the morning of Wednesday, May 17, reported the water main construction samples and a second fax on that afternoon reported the distribution and well #7 results. The general manager was busy all of that day, not returning to the office until the following morning, Thursday, May 18, when he would have found these faxes among other papers left on his desk.
Environmental Compliance and Control for Radiopharmaceutical Production
Michael Ljungberg in Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
Fourth, in addition to aseptically performed operations, membrane filtration is a commonly used approach for radiopharmaceutical preparation using a bacterial retention filter to abate the microbiological risk derived from the above compromised solutions. Accordingly, an integrity test usually has to be performed immediately after the preparation. However, it adds an additional risk for radiation exposure, even if rinsing the filter before the integrity test is performed. Thus, an alternative filter-based sterilization method of radiopharmaceuticals has been suggested, with the use of two filters in series and waiving the integrity testing before release [26].
Principles of Radioiodination and Iodine-Labeled Tracers in Biomedical Investigation †
Garimella V. S. Rayudu, Lelio G. Colombetti in Radiotracers for Medical Applications, 2019
Membrane filtration consists of filtering a radiopharmaceutical solution through a membrane filter of low porosity (0.22 μm) which removes organisms and radiocolloids by sieving. The Millipore® filter is made of cellulose ester, and the Nucleopore® filter is made of polycarbonate material. Membrane filtering is the most useful technique for short-lived and heat-labile labeled proteins, peptides, and enzymes, as well as other labeled molecules.
Lipid nano-bubble combined with ultrasound for anti-keloids therapy
Published in Journal of Liposome Research, 2018
Xiao Qing Wang, Zhou-Na Li, Qi-Ming Wang, Hong-Yan Jin, Zhonggao Gao, Zhe-Hu Jin
Membrane filtration (Xu et al., 2009) was used to measure the EE of 4HPR-L and 4HPR-LM because 4HPR was almost insoluble in water. 4HPR was easy to precipitate in aqueous solution and barely passed through 0.22 μm filtration membrane. However, liposomes solubilized 4HPR to form 4HPR-L solution that could pass through 0.22 μm filtration membrane due to small size of 4HPR-L. Therefore, the non-encapsulated 4HPR could be separated from 4HPR-L solution by the membrane filtration method for calculating the EE and loading efficiency. To verify the hypothesis, a verification test was performed and the results showed that 4HPR was not detected by HPLC after three subsequent filtrates. It was demonstrated that the membrane filtration method was applicable for our study. The EE and the loading efficiency of 4HPR-LM were 94.48 ± 1.05% and 8.31 ± 0.33%, respectively.
Plasma exchange as an adjunctive therapy in anti-neutrophil cytoplasm antibody-associated vasculitis
Published in Expert Review of Clinical Immunology, 2023
Kavita Gulati, Charles D Pusey
Plasma exchange can be performed using two main automated systems: centrifugal and membrane filtration [71]. In the centrifugal system, whole blood is extracted via venous access, and the plasma separated via centrifugation from cellular components [85,86]. The plasma supernatant is removed, with the remaining blood returned to the patient after being mixed with appropriate replacement fluid. The membrane filtration system pumps the patient’s blood through a hollow fiber filter, the membrane of which allows only the passage of plasma, which is subsequently removed, but not cells. The main difference between the two methods is that in membrane-based TPE, only molecules that are less than three million Daltons can be removed, whereas the centrifugal method does not have an upper limit. This implies that membrane-based TPE leads to less effective clearance of larger molecules such as IgM, cryoglobulins, and immune complexes [85,86].
Evaluating the effect of antiscalants on membrane biofouling using FTIR and multivariate analysis
Published in Biofouling, 2019
Mohammad Y. Ashfaq, Mohammad A. Al-Ghouti, Hazim Qiblawey, Nabil Zouari
Conventionally, membrane fouling and antifouling studies are conducted in a membrane filtration setup. Depending upon the type of fouling under investigation, the experiments are usually conducted from few hours to weeks and the setup mandates inclusion of high-pressure pumps, flow meters, pressure gauges and membrane filtration cells, which makes it a time consuming and costly methodology. In recent research, a method of quantifying biofilm formation using microbiology-based assays was proposed (Lutskiy et al. 2015). The suggested methodology was successfully applied to quantify the early stage of biofilm formation on RO and nanofiltration (NF) membranes. The effect of an antimicrobial polypeptide (nisin) on biofouling was recently studied using similar methodology (Jung et al. 2018). Therefore, it can be concluded that such assays are useful for evaluating the performance of membranes coated with anti-microbial materials to give early information about the performance of modified membranes without the use of complex filtration setups. Similarly, such assays can further be utilized to study the factors affecting microbial growth/viability (eg antiscalants), a critical step in biofouling.
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