通電による異常増殖した藻類の除去

This study investigated a method of removing algae by energizing a metal electrode plate set in water containing abnormally proliferated algae. As algae have negative charge in water, they migrated to the anode by electrophoresis in an electric field. Combining with cations eluting from the anode, especially aluminum ions, the algae formed cohesive floc and then adhered on the anode surface without returning into the water. In the continuous flow apparatus, algae were removed at high removal rate by taking out the algae adhered on anode regularly. It was shown that the electrochemical method can efficiently remove algae from water

Advances in Sample Preparation at the National Ocean Sciences Accelerator Mass Spectrometry Facility (NOSAMS): Investigation of Carbonate Secondary Standards

The development of robust sample preparation techniques for ocean science research has been a hallmark of NOSAMS since its inception. Improvements to our standard methods include reducing the minimum size of the samples we can analyze, building modular graphite reactors of different sizes that we can swap in and out depending on our sample stream, and modifying our carbonate acidification methods to improve handling of the smaller samples we now receive. A relatively new instrument, the Ramped PyrOx, which allows the separation of organic matter into thermal fractions, has attracted much interest as a research and development tool. We will also discuss our progress on incorporating a Picarro isotope analyzer into our sample preparation options

Competency Assessment in the Clinical Microbiology Laboratory

The laboratory comprises an invaluable part of the total health care provided to patients. Competency assessment is one method by which we can verify that our employees are competent to perform laboratory testing and report accurate and timely results. To derive the greatest benefit from the inclusion of competency assessment in the laboratory, we must be sure that we are addressing areas where our efforts can be best utilized to optimize patient care. To be competent, an employee must know how to perform a test, must have the ability to perform the test, must be able to perform the test properly without supervision, and know when there is a problem with the test that must be solved. In some cases, competency assessment protocols may demonstrate areas of competence but can fail to disclose incompetence. For example, challenges of low-complexity tasks (such as reading the technical procedure manual) are inferior to challenges that measure understanding and execution of a protocol, and poorly designed competency challenges will probably not detect substandard laboratory performance. Thus, if we are to receive the greatest benefit from our competency assessment programs, which may be time-consuming for the supervisors and the staff as well, we must not only meet the letter of the law but also find a way to make these assessments meaningful, instructive, and able to detect areas of concern. As we address competency assessment in our laboratories, we must understand that when done properly, competency assessment will reward our organizations and assist us in providing the best possible care to our patients

Effects of Time, Temperature, and Storage Container on the Growth of Fusarium Species: Implications for the Worldwide Fusarium Keratitis Epidemic of 2004-2006

Objective: To demonstrate the effects of time, temperature, and container properties on the ability of ReNu with MoistureLoc (ReNuML; contains the antimicrobial agent alexidine) to inhibit growth of Fusarium species. Methods: ReNu with MoistureLoc was stored in its Bausch & Lomb (Rochester, New York) plastic or similarly sized glass containers for 1 and 4 weeks at room temperature, 42°C, and 56°C, and then tested for its ability to inhibit growth of 7 Fusarium isolates. Results: ReNu with MoistureLoc stored in glass containers for 1 or 4 weeks at all 3 temperatures demonstrated no significant fungistatic deterioration. However, ReNuML stored at 56°C in its Bausch & Lomb plastic container demonstrated a statistically significant fungistatic deterioration compared with room temperature storage in its original plastic container or with glass container storage at any temperature. Conclusion: When exposed to elevated storage temperature, it appears that an interaction between ReNuML and its Bausch & Lomb plastic container adversely affects the fungistatic properties of ReNuML, which could have contributed to the Fusarium keratitis epidemic of 2004 through 2006

Microbiological Investigations of ReNu Plastic Bottles and the 2004 to 2006 ReNu With MoistureLoc-Related Worldwide Fusarium Keratitis Event

Purposes: The purposes of this study were to determine whether the contact lens solution RevitaLens Ocutec (containing the antimicrobial agents alexidine and polyquaternium-1) would inhibit Fusarium organisms when heated in ReNu plastic bottles; whether alexidine would inhibit Fusarium organisms when heated in non-ReNu plastic bottles; and whether an alexidine-neutralizing compound leaches from heated ReNu bottles. Methods: RevitaLens and an alexidine solution (0.00045%), previously stored in ReNu bottles at room temperature (RT) and 56°C, were incubated with 7 different Fusariumorganisms. The alexidine solution was similarly stored in seven non-ReNu plastic bottles and incubated with these same organisms. To determine if an alexidine-neutralizing compound might be leaching from heated ReNu bottles, phosphate-buffered saline (PBS) was incubated at RT and 56°C in ReNu bottles, combined with alexidine, and then tested for anti-Fusariumcapability. Results: After being heated in ReNu bottles, RevitaLens retained its anti-Fusarium capability, whereas the alexidine solution did not. The alexidine solution heated in seven non-ReNu plastic bottles retained its anti-Fusarium capability. The alexidine solution retained its anti-Fusarium capability when incubated with a PBS solution that had been heated in ReNu bottles, indicating, microbiologically, that an alexidine-neutralizing compound did not leach from the heated ReNu bottle. Conclusions: Alexidine uniquely fails to inhibit Fusarium organisms when heated in a plastic ReNu bottle, but not in seven other plastic bottles, whereas the anti-Fusarium capability of RevitaLens (containing the antimicrobial agents alexidine and polyquaternium-1) is unaffected by heating in a ReNu bottle. There does not seem to be an alexidine-neutralizing compound leaching from heated ReNu bottles. An interaction between alexidine and its heated ReNu bottle may have been a critical factor in the worldwide ReNu with MoistureLoc-related Fusarium keratitis event of 2004 to 2006

Pan-Antimicrobial Failure of Alexidine as a Contact Lens Disinfectant When Heated in Bausch & Lomb Plastic Containers: Implications for the Worldwide Fusarium Keratitis Epidemic of 2004 to 2006

Objective: ReNu with MoistureLoc (ReNuML), containing the antimicrobial agent alexidine 0.00045%, was associated with the Fusarium keratitis epidemic of 2004 to 2006. Although a single-point source contamination was ruled out, only Fusarium organisms were reported during the outbreak. This study investigated whether the reported loss of antimicrobial effectiveness toward Fusarium of ReNuML after exposure to heat in high-density polyethylene (HDPE) plastic containers could also be demonstrated with other common fungal and bacterial agents of keratitis. Methods: A buffered solution of alexidine 0.00045% was incubated in glass and ReNu HDPE plastic containers at room temperature (RT) and 56°C for 4 weeks, serially diluted, and tested for its ability to inhibit the growth of 20 bacterial isolates, 12 non-Fusarium fungal isolates, and 7 Fusarium isolates originally involved in the keratitis epidemic. Results: A statistically significant loss of antimicrobial capability was seen with all fungi, all gram-positive bacteria, and all isolates of Klebsiella when alexidine 0.00045% was incubated at 56°C in ReNu HDPE containers compared with RT or glass incubation (P≤0.0001). Conclusions: Heating of an alexidine solution in ReNu HDPE plastic (but not glass) containers results in the same loss of anti-Fusarium activity as reported when testing the original ReNuML solution. This loss of inhibitory activity is not specific to Fusarium and occurs with other fungi and bacteria that cause keratitis. The reasons for the lack of reports of bacterial and/or non-Fusarium fungal keratitis during the original Fusarium keratitis epidemic remain unclear at this time

Pan-Antimicrobial Failure of Alexidine as a Contact Lens Disinfectant When Heated in Bausch & Lomb Plastic Containers: Implications for the Worldwide Fusarium Keratitis Epidemic of 2004 to 2006

Objective: ReNu with MoistureLoc (ReNuML), containing the antimicrobial agent alexidine 0.00045%, was associated with the Fusarium keratitis epidemic of 2004 to 2006. Although a single-point source contamination was ruled out, only Fusarium organisms were reported during the outbreak. This study investigated whether the reported loss of antimicrobial effectiveness toward Fusarium of ReNuML after exposure to heat in high-density polyethylene (HDPE) plastic containers could also be demonstrated with other common fungal and bacterial agents of keratitis. Methods: A buffered solution of alexidine 0.00045% was incubated in glass and ReNu HDPE plastic containers at room temperature (RT) and 56°C for 4 weeks, serially diluted, and tested for its ability to inhibit the growth of 20 bacterial isolates, 12 non-Fusarium fungal isolates, and 7 Fusarium isolates originally involved in the keratitis epidemic. Results: A statistically significant loss of antimicrobial capability was seen with all fungi, all gram-positive bacteria, and all isolates of Klebsiella when alexidine 0.00045% was incubated at 56°C in ReNu HDPE containers compared with RT or glass incubation (P≤0.0001). Conclusions: Heating of an alexidine solution in ReNu HDPE plastic (but not glass) containers results in the same loss of anti-Fusarium activity as reported when testing the original ReNuML solution. This loss of inhibitory activity is not specific to Fusarium and occurs with other fungi and bacteria that cause keratitis. The reasons for the lack of reports of bacterial and/or non-Fusarium fungal keratitis during the original Fusarium keratitis epidemic remain unclear at this time