Extremely low frequency (ELF) stray magnetic fields of laboratory equipment: a possible co-exposure conducting experiments on cell cultures

Abstract

Measurements of extremely low frequency (ELF) magnetic fields were conducted in the environment of commercial laboratory equipment in order to evaluate the possible co-exposure during the experimental processes on cell cultures. Three types of device were evaluated: a cell culture CO₂ incubator, a thermostatic water bath and a laboratory shaker table. These devices usually have electric motors, heating wires and electronic control systems, therefore may expose the cell cultures to undesirable ELF stray magnetic fields. Spatial distributions of magnetic field time domain signal waveform and frequency spectral analysis (FFT) were processed. Long- and short-term variation of stray magnetic field was also evaluated under normal use of investigated laboratory devices. The results show that the equipment under test may add a considerable ELF magnetic field to the ambient environmental magnetic field or to the intentional exposure to ELF, RF or other physical/chemical agents. The maximum stray magnetic fields were higher than 3?µT, 20?µT and 75?µT in the CO₂ incubator, in water bath and on the laboratory shaker table, respectively, with high variation of spatial distribution and time domain. Our investigation emphasizes possible confounding factors conducting cell culture studies related to low-level ELF-EMF exposure due to the existing stray magnetic fields in the ambient environment of laboratory equipment.     

北美国家大动物生物安全实验室的建设与管理

目的 为提高动物实验室生物安全意识,供大动物生物安全实验室设计、施工、使用和管理借鉴.方法 采用考察和分析的方法了解了北美国家大动物生物安全实验室的设计理念、设备、设施、动物试验及动物实验室管理.结果 大动物生物安全实验宝与我国畜牧业健康发展和社会稳定密切相关,我国与国外大动物生物安全实验室存在较大的差距.结论 我国应借鉴国外大动物生物安全实验室设计的理念,完善大动物实验室基础设施,增设相应的设备和提升动物实验室工作人员的生物安全意识.     

A SIMPLIFIED METHOD FOR THE URINARY EXCRETION TEST OF ABSORPTION OF COBALT 60 LABELLED VITAMIN B12

It is possible to do both radioiodine uptake studies and urinary excretion tests for absorption of Cobalt 60 vitamin B₁₂ with the same basic equipment. If a spectrometer is used and the samples properly prepared, the latter procedure can be performed quickly, accurately and with a minimum of laboratory equipment. This is a distinct advantage to a small laboratory with limited facilities, and should help to make both of these useful tests available for clinical use.     

Biological Containment Facility for Studying Infectious Disease

To effectively characterize newly recognized viruses (Marburg, Lassa, etc.) and to study other highly virulent infections for which no effective prophylaxis or therapy exists, special containment facilities must be utilized and conventional techniques modified to minimize risk to laboratory personnel. This paper describes a laboratory suite for such studies, contained within a larger research facility; two separate biological safety cabinet systems, animal rooms support laboratories, change room facilities, shower, air lock, and other safety features are contained in the area. Details of design, construction, airflows, and equipment are described in addition to a discussion of operation, techniques, and modification of laboratory equipment utilized in actual studies.     

Optimization of the spraying equipment and technology used in ornamental crops

In 2006, a research project concerning the optimization of the spraying equipment and technology used in ornamental crops was started. First, several greenhouse growers were surveyed on the spray equipment and technology they were using for their plant protection. Later on, different parts of their equipment were evaluated. It this way, we could advice the connected growers on how to improve their own techniques and equipment. Additionally, the survey showed that growers predominantly use knapsack sprayers and lances for crop protection purposes. These techniques are often proven to be less effective compared to spray booms, which could explain the high application rates (up to 6650 L ha(-1)) used by most growers. Since spray boom equipment could enhance spray distribution and minimize labour cost, operator exposure; the usability of this technique in ornamental crops was studied by means of laboratory tests, field trials and bio-efficacy experiments.     

Exploration and Practice of Biological Engineering Experiment Reform

Reform of experimental teaching should be the integration of relevant experimental courses,rational use of laboratory equipment to share resources and improve equipment utilization.Experimental results showed that the teaching reform significantly improved the utilization of laboratories and equipment,and significantly enhanced the practical ability of students.     

Pacemaker patients' perception of unsafe activities: a survey

Background

The ankle brachial index (ABI) is a well-established tool for screening and diagnosis of peripheral arterial disease (PAD). In this study we assessed the validity of ABI determination using a pocket Doppler device compared with automatic vascular laboratory measurement in patients suspected of PAD.

Methods

Consecutive patients with symptoms of PAD referred for ABI measurement between December 2006 and August 2007 were included. Resting ABI was determined with a pocket Doppler, followed by ABI measurement with automatic vascular laboratory equipment, performed by an experienced vascular technician. The leg with the lowest ABI was used for analysis.

Results

From 99 patients the mean resting ABI was 0.80 measured with the pocket Doppler and 0.85 measured with vascular laboratory equipment. A Bland-Altman plot demonstrated great correspondence between the two methods. The mean difference between the two methods was 0.05 (P < .001). Multivariate linear regression analysis showed no dependency of the difference on either the average measured ABI or affected or unaffected leg.

Conclusion

Since the small, albeit statistically significant, difference between the two methods is not clinically relevant, our study demonstrates that ABI measurements with pocket Doppler and vascular laboratory equipment yield comparable results and can replace each other. Results support the use of the pocket Doppler for screening of PAD, allowing initiation of cardiovascular risk factor management in primary care, provided that the equipment operator is experienced.     

Laboratory voice data entry system

We have assembled a system using a personal computer workstation equipped with standard office software, an audio system, speech recognition software and an inexpensive radio-based wireless microphone that permits laboratory workers to enter or modify data while performing other work. Speech recognition permits users to enter data while their hands are holding equipment or they are otherwise unable to operate a keyboard. The wireless microphone allows unencumbered movement around the laboratory without a "tether" that might interfere with equipment or experimental procedures. To evaluate the potential of voice data entry in a laboratory environment, we developed a prototype relational database that records the disposal of radionuclides and/or hazardous chemicals. Current regulations in our laboratory require that each such item being discarded must be inventoried and documents must be prepared that summarize the contents of each container used for disposal. Using voice commands, the user enters items into the database as each is discarded. Subsequently, the program prepares the required documentation.     

Immunology on chip: Promises and opportunities

Microfluidics has facilitated immunological studies by enhancing speed, efficiency and sensitivity of current analysis methods. It offers miniaturization of current laboratory equipment, and enables analysis of clinical samples without the need for sophisticated infrastructure. More importantly, microfluidics offers unique capabilities; including conducting multiple serial or parallel tasks as well as providing complex and precisely controlled environmental conditions that are not achievable using conventional laboratory equipment. Microfluidics is a promising technology for fundamental and applied immunological studies, allowing generation of high throughput, robust and portable platforms, opening a new area of automation in immunology.     

Experience with a Hospital Laboratory Admission Screen

A comprehensive laboratory admission screen can be instituted in any large laboratory but only in one in command of conventional technology and with the co-operation of the laboratory, medical, nursing and admitting staff.The capital equipment required is costly and subject to early obsolescence. The operating costs are initially high, but the influence of the screen on the general work load indicates that the total overall procedures ordered by the physician will be reduced in number and that over a three-year period, in an economy subject to continuous inflationary pressure, the total cost will approach what might have been expected had the screen not been instituted.By presenting, shortly after admission, a truly comprehensive laboratory profile, the total number of procedures ordered will be reduced and this reduction bears no relationship to whether or not the data supplied are medically useful.The equipment more recently available for a large admission screen is far superior, from the point of view of speed of assay and cost of maintenance and production, to the equipment that has been available to us in this study.It is believed that the unit cost of assay will continue to decline and that the principle of unsolicited testing will be expanded in the future to include procedures not presently in the profile.It is predicted that in the relatively near future almost all of the laboratory procedures that a clinician could conceivably request will have been done prior to his examination of the patient.     

Laboratory diagnosis of Yersinia infection and its improvement

Results of the bacteriological and serological tests of patients with Y. enterocolitica and Y. pseudotuberculosis infections for the period from 1994 to 2004 were analyzed. Main reasons of imperfect laboratory diagnostics were revealed, such as, low sensitivity of bacteriologic test, nonobservance of existing recommendations on diagnostics of Yersinia infections, performing of single but not repeated serologic test, absence of necessary laboratory equipment. Main ways of improving of quality of Y. enterocolitica infections and differential diagnostics were of Y. pseudotuberculosis defined.     

INVITED SPECIAL PAPER: History of the botanical teaching laboratory in the United States

The establishment of teaching laboratories for botany in the United States was strongly influenced in the early part of the 19th century by the founding of a laboratory of natural history at the Rensselaer School by Amos Eaton who inspired numerous educators, particularly women. By midcentury and later, botany programs were established at land-grant colleges and the so-called “new Botany” movement spread from them. In the latter part of the century additional changes were brought about by the influence of German laboratory activity and botanists’ reactions to the introduction of the Huxley-Martin biology programs to America. During these times, Americans were improving their own manufactured microscopes, laboratory supplies, and equipment capabilities. By the beginning of the 20th century, laboratory teaching of botanical subjects was widely accepted as normal in universities and colleges, as well as in some high schools.     

Efficacy of vaporized hydrogen peroxide against exotic animal viruses.

The efficacy of vapor-phase hydrogen peroxide in a pass-through box for the decontamination of equipment and inanimate materials potentially contaminated with exotic animal viruses was evaluated. Tests were conducted with a variety of viral agents, which included representatives of several virus families (Orthomyxoviridae, Reoviridae, Flaviviridae, Paramyxoviridae, Herpesviridae, Picornaviridae, Caliciviridae, and Rhabdoviridae) from both avian and mammalian species, with particular emphasis on animal viruses exotic to Canada. The effects of the gas on a variety of laboratory equipment were also studied. Virus suspensions in cell culture media, egg fluid, or blood were dried onto glass and stainless steel. Virus viability was assessed after exposure to vaporphase hydrogen peroxide for 30 min. For all viruses tested and under all conditions (except one), the decontamination process reduced the virus titer to 0 embryo-lethal doses for the avian viruses (avian influenza and Newcastle disease viruses) or less than 10 tissue culture infective doses for the mammalian viruses (African swine fever, bluetongue, hog cholera, pseudorabies, swine vesicular disease, vesicular exanthema, and vesicular stomatitis viruses). The laboratory equipment exposed to the gas appeared to suffer no adverse effects. Vaporphase hydrogen peroxide decontamination can be recommended as a safe and efficacious way of removing potentially virus-contaminated objects from biocontainment level III laboratories in which exotic animal disease virus agents are handled.     

医学高校实验室建设问题的探讨

高等学校实验室是教学、科研的重要场所,是培养具有创新能力和发散思维的科学研究与应用型人才的实验平台。高校实验室建设情况和管理水平,直接影响到学校教学质量和科研水平的高低。要建设高水平实验室,在重视设备投入的同时,必须重视实验技术队伍的同步建设,除此之外合理的实验室结构和资源配置、高水平的实验教学质量和高效率的管理工作等软件条件也不可或缺。只有大力加强实验室建设,才能更好应对医学教育领域呈现的综合化、一体化发展趋势,形成利于实验教学效益发挥的良性运行机制,实现实验室的可持续发展。     

Accuracy of the StressEraser<Superscript>®</Superscript> in the Detection of Cardiac Rhythms

StressEraser is a commercially marketed biofeedback device designed to enhance heart rate variability. StressEraser makes its internal calculations on beat-to-beat measures of finger pulse intervals. However, the accuracy and precision of StressEraser in quantifying interbeat intervals using finger pulse intervals has not been evaluated against standard laboratory equipment using R-R intervals. Accuracy was assessed by simultaneously recording interbeat intervals using StressEraser and a standard laboratory ECG system. The interbeat intervals were highly correlated between the systems. The average deviation in interbeat interval recordings between the systems was approximately 6 ms. Moreover, correlations approached unity between the systems on estimates of heart period, heart rate, and heart rate variability. Feedback from StressEraser is based on an interbeat time series that provides sufficient information to provide an excellent estimate of the dynamic changes in heart rate and heart rate variability. The slight variations between StressEraser and the laboratory equipment in quantifying heart rate and heart rate variability are due to features related to monitoring heart rate with finger pulse: (1) a lack in precision in the peak of the finger pulse relative to the clearly defined inflection point in the R-wave, and (2) contribution of variations in pulse transit time.     

Biorisk assessment of natural science laboratories of Bicol University College of Science,Philippines

A biorisk assessment of natural science laboratories in Bicol University was conducted as an initial step towards improvement of laboratories and contributing to a culture of safety in the university. Survey among laboratory workers and ocular inspection of natural science labs was done. Results showed that gaps exist in the safety knowledge and practices of laboratory workers. Microbial assets pose the lowest risk, while equipment and the use of chemicals in biological assays pose the highest risk. The likelihood that such events will occur ranges from low to moderate while consequences range from moderate to high. The research recommends that a policy on biological safety be formulated and be integrated in the overall safety guidelines of the university, that existing guidelines and SOPs be improved and that their implementation be monitored, to introduce a course for undergraduates that will tackle the basics of safety and security in the laboratory, and that the equipment and physical design be improved to reduce the risks to acceptable levels.     

Teaching human cardiovascular and respiratory physiology with the station method

We have developed a station method to offer combined cardiovascular and respiratory physiology exercises all in one laboratory period during our medical physiology course. This laboratory was designed for first-year medical students in order to minimize equipment costs, maximize efficient use of both student and faculty time, and facilitate integration of basic cardiovascular concepts with those in respiratory physiology. We designed six stations for the students to evaluate: cardiovascular and respiratory responses to dynamic exercise, cold pressor reflex, postural influences and respiratory modulation of cardiovascular functions, forced expiratory maneuvers with inverted bell spirometers, forced expiratory maneuvers and maximal inspiratory maneuvers with electronic spirometers with and without obstruction, and respiratory muscle strength. Students worked in groups of two to four and were assessed by individual laboratory reports. Although we neglected to formally assess the impact on students of changes in laboratory design, students appeared to respond enthusiastically to the laboratory and prepared knowledgeable laboratory reports.     

Precautions for workers using radioactive isotopes

Radioactive isotopes are now available from Chalk River for use by Canadian biologists. Experience has shown that the handling of radioactive isotopes may involve health hazards unless adequate precautions are taken. The nature of these hazards and the type of precautions which must be taken when working with radioactive isotopes are considered. Successful work with radioactive isotopes other than in the smallest tracer amounts requires the use of laboratories and equipment especially designed for the purpose and this is dealt with briefly. The operation of a radioactive laboratory requires certain auxiliary equipment and services, such as health instruments, film monitoring, special laboratory clothing, special cleanable surfaces and disposal of radioactive waste materials. These topics are discussed briefly. Handling of radioactive isotopes involves certain special precautions and a few of these, such as protection of hands, cleaning of glassware, handling of solutions, etc. are reviewed. In addition to protecting all personnel in a laboratory from harmful amounts of radiation, it is necessary to keep the laboratory and the building in which it is housed as free as possible from radioactive substances and this important fact has been stressed.     

An improved ‘pooter”

This manually operated ‘pooter’ is easily made from standard laboratory equipment     

Overview: methods and applications for droplet compartmentalization of biology

Three protocols in this issue highlight applications of emulsification procedures, which deliver high-throughput potential to the molecular biology laboratory, without the need for automation. These procedures have already generated interesting results and spurred the development of exciting new technologies, while requiring only readily available laboratory equipment.