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Summary The ESR spectra produced in irradiated dentin have been studied over a range of incident radiation energies from 50 kVp to 25 MVp. The behavior of the dentin ESR signal strength is similar to that of enamel as a function of the energy of the incident radiation. The magnitude of the dentin ESR signals are, however, up to 10 times smaller than the signals of dental enamel for a given radiation energy. The possible contributions of radiation interaction coefficients, chemical structure, and crystallite size to the differences in ESR spectra are discussed.  相似文献   
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Many hospitals are faced with the development of radiation emergency plans. Details are given of the relevant literature and audio-visual materials to assist in the development of such a plan.  相似文献   
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End-of-life (EOL) and palliative care education in medical school curricula stand at a crossroads. Consensus has emerged that these topics merit systematic instruction throughout medical school training, yet curricula all too often consist of sporadic lectures focused on bioethics instead of clinical skills. The medical student authors identified a deficit in their curriculum, and designed and implemented an EOL curriculum module for their colleagues. In early 2000 the authors surveyed senior medical students about their experiences with EOL and palliative education, identifying deficits in clinical training and recommendations for interventions. They then designed a case-based educational module to teach EOL communication skills to medical students commencing clinical training. Faculty with national and local experience with EOL and palliative care reviewed the curriculum. Twelve of these faculty were oriented to the curriculum and then taught it in pairs to groups of 12 to 16 medical students in 2000 and 2001. The curriculum develops skills, attitudes, and knowledge relevant for communicating bad news and establishing treatment options in the EOL setting by utilizing trigger videos, group discussion, role plays, and case discussions. Approximately 75% of the 86 eligible students attended the module in 2000 and 2001. Feedback has guided the curriculum's refinement by the medical student authors. In addition, a standardized patient exercise, introduced in 2001, allowed students to reinforce the skills learned during the module.  相似文献   
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Alterations in the genomes of avian sarcoma viruses   总被引:3,自引:0,他引:3  
We have identified polypeptides specific to region Elb (map position [mp] 4.6–112) of adenovirus 2 (Ad2) that are synthesized in six lines of Ad-transformed rat or human cells (F17, F4, T2C4, 8617, 5RK clone I, 293), and in Ad2 early infected KB cells. [35S]Methionine-labeled polypeptides were immunoprecipitated using antisera against F17 cells, an Ad2-transformed rat cell line that retains only El. To determine whether they are viral coded, these polypeptides were compared by tryptic peptide mapping with polypeptides translated in vitro from Ela-specific mRNA (mp 1.3–4.5) and Elb-specific mRNA. Polypeptides of 19,000 daltons early infected KB cells. The 19K, 20K, and 53K could be translated from Elb-specific mRNA and thus are coded by Elb. The 19K was precipitated from all transformed cell lines, the 20K was immunoprecipitated from F4, 8617, and T2C4 cells, and the 53K was immunoprecipitated from F4, 8617, T2C4, and 293 cells. These results suggest that the 19K, and perhaps the 20K and 53K, may be important in adenovirus-induced cell transformation. The 20K and 53K share methionine-containing tryptic peptides with each other, but not with the 19K. These results, together with the Ad2 Elb DNA sequence (T. Gingeras and R. Roberts, personal communication), suggest that 19K is translated in a different reading frame from 53K and 20K.  相似文献   
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Experimental transmission of duck hepatitis B virus   总被引:22,自引:0,他引:22  
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