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The Advisory Committee on Human Radiation Experiments (ACHRE), established to review allegations of abuses of human subjects in federally sponsored radiation research, was charged with identifying appropriate standards to evaluate the ethics of cold war radiation experiments. One central question for ACHRE was to determine what role, if any, the Nuremberg Code played in the norms and practices of US medical researchers. Based on the evidence from ACHRE's Ethics Oral History Project and extensive archival research, we conclude that the Code, at the time it was promulgated, had little effect on mainstream medical researchers engaged in human subjects research. Although some clinical investigators raised questions about the conduct of research involving human beings, the medical profession did not pursue this issue until the 1960s.

Convinced that armed conflict with the Soviet Union was all but inevitable, that such conflict would involve unconventional atomic, biological, and chemical warfare, and that research with human subjects was essential to respond to the threat, in the early 1950s the U.S. Department of Defense promulgated a policy governing human experimentation based on the Nuremberg Code. Yet the policymaking process focused on the abstract issue of whether human experiments should go forward at all, ignoring the reality of humans subjects research already under way and leaving unanswered ethical questions about how to conduct such research. Documents newly released to the Advisory Committee on Human Radiation Experiments tell the story of the Pentagon policy.

A review is made in this paper on the recent advances of the photo‐ and electro‐luminescence properties of porous silicon (PS). We start by describing the electrochemical formation mechanisms of PS, followed by the most significant results obtained by different structural and chemical characterization techniques. Next we discuss the origin of the strong visible photoluminescence observed at room temperature in PS. Finally the possibility of using PS structures as electroluminescent devices and photodetectors is discussed. For this application the use of transparent conductive polymer films as electrical contacts to PS is considered.

We have measured the Raman spectrum of porous silicon layers for different light polarizations. For the polarizations where the first-order Raman peak is forbidden in bulk silicon, porous silicon shows a band. This band is almost as intense as the one in the allowed polarizations but its lineshape is very different. The ‘forbidden’ band is usually wider and shifted to lower energies with respect to the allowed band. Both bands are analyzed in terms of sample characteristics, layer depth, and excitation wavelength.

We report on the strong temperature-dependent thermal expansion, D, in CdS quantum dots (QDs) embedded in a glass template. We have performed a systematic study by using the temperature-dependent first-order Raman spectra, in CdS bulk and in dot samples, in order to assess the size dependence of D, and where the role of the compressive strain provoked by the glass host matrix on the dot response is discussed. We report the Gr¨ uneisen mode parameters and the anharmonic coupling constants for small CdS dots with mean radius R 2:0 nm. We found that parameters change, with respect to the bulk CdS, in a range between 20 and 50%, while the anharmonicity contribution from two-phonon decay channel becomes the most important process to the temperature-shift properties. (Some figures may appear in colour only in the online journal)

The problem of finding appropriate decisionmakers for incapacitated patients continues to beleaguer caregivers. In New York state, a specially appointed task force has recently examined this issue and made some novel recommendations.

More than 5000 women infected with human immunodeficiency virus give birth annually in the United States. Many of these women are offered human immunodeficiency virus tests in prenatal settings. One of the incentives for them to be tested is access to medications that have been shown to prolong disease-free intervals in nonpregnant human immunodeficiency virus-infected individuals. However, the use of those medications during pregnancy has not been well studied and some have cautioned against their prenatal use. Thus consideration of these agents may be deferred by some clinicians until the postpartum period. In this article we argue that the availability of such agents should be disclosed to women who are seropositive for human immunodeficiency virus as part of the informed consent process.

Recent efforts to support state regulation of risky behavior like cigarette smoking, alcohol consumption, driving without seatbelts and riding motorcycles without helmets have focused on economic justifications--the costs to society of the consequences of these activities. However, opponents have successfully argued that the economic burdens of regulation outweigh the social benefits. To reduce the toll on society of these behaviors, we need justification for regulation that asserts the moral primacy of health and the well-being of the community.Recent public policy debates over seatbelt and motorcycle helmet laws and taxes on alcohol and tobacco are described and evaluated. Advocates of stronger state actions in these areas are faulted for framing their justifications almost solely in economic terms, leaving their opponents able to argue that the economic burdens of regulation outweigh the social benefits. It is concluded that the justification for such regulation must include an assertion of the moral primacy of health as a social good and of the well-being of the community as a legitimate concern of public policy.

Moreno reports on recent activities in Washington, D.C., that could affect future genetic research. Concerned about the implications of genetic interventions in humans, 63 theologians and scientists released a statement on 8 June 1983 calling for a congressional moratorium on genetic research that could alter the human germline. An alternative to banning genetic experimentation would be the creation of a body to evaluate such research. Among the proposals under consideration are establishing a new President's Commission, setting up an ethics committee under the jurisdiction of the National Academy of Science's Institute of Medicine, or expanding the National Institutes of Health's Recombinant DNA Advisory Committee.

Systemic methodology is restored to so that a demonstration is made which shows hallucination not being an independent element. Quite contrary, it is the author's contention that this is a structure-formed interacting group element coupled in function of an arrangement the basis pathology thus determined. I.E., hallucination is an open system at a set point with pathology. Hence--within certain limits, of course--the equilibrium establishes an arrangement whose characteristics enable any observer to identify hallucination as such. Since the methodology is in accordance with the General System Theory, the elements involved are studied like functional parts within a system. In other words, neither determinism nor simple causation are resorted to. Since--according to the GST--there is a higher relevance among connected elements which is not to be found among independent ones, thus a functional description is of a higher relevance than a particular one. So, the structure is proposed as a functional arrangement.

The subject is approached from the standpoint of the debates and events of the "Baby Doe era," from 1982 to 1985. Historic episodes of mass infanticide and practices in other cultures, while often cited as warnings of moral peril, are difficult to apply to the problem of infant euthanasia. Key cases in American courts are reviewed, although no standard pattern of analysis is found to have emerged. The two streams of policy making at the national level, from the Department of Health and Human Services and the Congress, have effectively led back to underlying ethical dilemmas about the proper interpretation of the infant patient's best interests. The conclusion alludes to several issues that neonatal ethics has yet to confront.

Polypyrrole has been electrocleposited in the interior of the pores that form the Porous Silicon structure, and a very significant increase of the electrical conductivity of the samples has been observed. The degree of filling by the polymer has been found to be highly dependent on the electropolymerization conditions. Micro-Raman Spectroscopy experiments have allowed us to measure the amount of polymer as a function to the distance from the outer PS surface.

3 pages, 3 figures., We have measured depth-resolved microphotoluminescence (PL) and micro-Raman spectra on the cross section of porous silicon multilayers to sample different layer depths. The PL emission band gets stronger, blueshifts, and narrows at the high porosity layers. On the contrary, the Raman band weakens and broadens. This band is fitted to the phonon confinement model. With the bulk silicon phonon frequency and its linewidth as free parameters, we obtain crystallite size, temperature, and stress as a function of depth. Sizes are larger than those estimated from PL. Laser power was reduced to eliminate heating effects. Compressive stresses in excess of 10 kbar are found in the deepest layer due to the lattice mismatch with the substrate., The authors acknowledge financial support from the Spanish CICyT (Project Nos. MAT96-0395-CP and MAT97- 0725).

The line shape of the one phonon Raman peak has been used extensively in the literature to estimate the crystallite size in porous silicon. However it has been shown that the line shape obtained on top surface experiments depends on the excitation wavelength. Because the porosity depends on depth, previous results are masked by the change in penetration depth. In this communication we report depth-resolved micro-Raman spectra at 514.5 and 632.8 nm. The spectra were measured at different points along a cross section of porous silicon films. We show that even when the same layer and, therefore, the same porosity is probed the Raman peak is broader at shorter wavelengths. To explain the results we suggest a contribution of indirect gaps to the resonant Raman cross section induced by quantum confinement.

Photoluminescent and electroluminescent properties of porous silicon layers were studied at different oxidation times after application of anodic current transients. Changes in the wavelength and intensity of the emitted photoluminescence could be explained as the consequence of a gradual electrooxidation of silicon structures. Also, the time delay associated with the recording of electroluminescence was interpreted as being due to the oxidation of bulk silicon by holes injected by the power supply. Once bulk silicon becomes oxidized, holes can reach the valence band of silicon microstructures where quantum size effects lead to visible light emission.

The morphological differences between porous silicon formed in the dark or under illumination have been studied by means of gravimetric measurements, transmission electron microscopy, infrared spectroscopy and cyclic voltammetry. Photoetching has been found to give rise to a complex surface structure, due to the presence of narrower outer silicon fibres, which suffer a more severe cracking process upon drying.

Polarized first-order Raman scattering studies at 300 K were carried out in L-asparagine monohydrate crystal in order to obtain the general assignment of its phonon spectra. A careful analysis of the vibrational spectra shows that the assignment of the fundamental vibrational modes can be done on the basis of amino, carboxilic and water groups vibrations, and correlations with previous data reported for other amino acids. However, some vibrations were correctly assigned from the study of its temperature - dependence behavior performed in the range 10 - 300 K. The assignment proposed cofirm the zwitterionic structure of L-asparagine monohydrate crystal.