Biomedical equivalence

Dose equivalent or rem is a special radiation protection quantity that is used, for administrative and radiation safety purposes only, to express the absorbed dose in a manner which considers the difference in biological effectiveness of various kinds of ionizing radiation. The ICRU has defined the dose equivalent, H, as the product of the absorbed dose, D, and the quality factor, Q, at the point of interest in biological tissue. This relationship is expressed as H = D x Q. The dose equivalent concept is applicable only to doses that are not great enough to produce biomedical effects. 

Despite the extensive experience with biomedical ethics, the infrastructure of institutional review boards (IRBs), and the equivalent for protection of human subjects (Schulte et al. 1997 but see Soskolne 1997), it is essential to address questions of ethics that may be particular to the design of biomonitoring studies. In this section, the committee considers some practical and research issues in biomonitoring ethics but makes no pretense that the list is exhaustive. Ethical issues can stop specific studies, and the field in general, dead in their tracks. Therefore, it is incumbent on investigators, policy-makers, and others to consider these issues carefully. 

Scientists continue to look for new andbetter materials out of which to form artificial blood vessels. In 1990, for example, the biomedical company Organogenesis began testing a material they called living blood vessel equivalent (LBVE), whose structure mimics the three-layer structure of natural blood vessels. The three layers, consisting of en-... 

Biomedical Applications. Spin-lattice relaxation times Ti and Tid as well as NMR second moment were employed to study the molecular dynamics of riboflavin (vitamin B-2) in the temperature range 55-350 K. The broad and flat T1 minimum observed at low temperatures is attributed to the motion of two non-equivalent methyl groups. The motion of the methyl groups is interpreted in terms of Haupt s theory, which takes into account the tunneling assisted relaxation. 

Adis PharmacoEconomics and Outcomes News 1994-. Chester, U.K. Adis International Limited. Daily. Adis Phar-macoEconomics and Outcomes News is a full text database and is the online equivalent to the weekly newsletter of the same name. It presents up-to-date analyses on world pharmacoeconomics and healthcare outcomes news, views, and practical application. More than 2000 major international medical, biomedical, and pharmacoeconomic journals are routinely scanned for inclusion. Available online. 

References should be cited in accordance with the 1979 Vancouver Declaration on Uniform Requirements for Manuscripts Submitted to Biomedical Journals or equivalent. 

In the United States it was as a direct result of the revelation of the Tuskegee Syphilis Study that the next U.S. medical ethics initiative emerged. The National Research Act of 1974 was passed (Public Law 93348), which required regulatory protection for human subjects and created the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research. In 1979 this commission produced the Belmont Report, named after the Smithsonian Institution s Conference Center, where the discussions were first held in 1976. The report established three ethical principles to allow problems to be solved in the area of ethics in clinical research (1) respect for persons, (2) beneficence, and (3) justice. In general terms, these categories were equivalent to informed consent, risk-benefit assessment, and an appropriate choice of subjects for the research. 

Yannas, I. V, 1995a, Artificial skin and dermal equivalents, in The Biomedical Engineering Handbook, J. Bronzino, ed., CRC Press, Boca Raton, EL, pp. 2025-2038. 

In addition to its nonpolarizable behavior, the silver-silver chloride electrode exhibits less electrical noise than the equivalent polarizable electrodes. This is especially true at low frequencies, and so silver-silver chloride electrodes are recommended for measurements involving very low voltages for signals that are made up primarily of low frequencies. A more detailed description of silver-silver chloride electrodes and methods to fabricate these devices can be found in Reference 3 and biomedical instrumentation textbooks [4]. 

Minimum Qualifications. A bachelor s degree (4 years) in an electrical or electronics program or its equivalent is required (preferably with a clinical or biomedical adjunct). A master s degree is desirable. A minimum of 3 years experience as a clinical engineer and 2 years in a progressively responsible supervisory capacity is needed. Additional qualifications are as follows ... 

Polyacetals that have been examined for biomedical applications are often prepared by step or condensation polymerizations. Utilizing a diol monomer and an aldehyde to prepare a polymer requires removal of 1 equivalent of water per acetal (Figure 13.1). Acetal exchange reactions can be used where the small molecule is an alcohol with a lower boiling point than water... 

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