Measurement of spin-transfer observables in p p-->Lambda Lambda at 1.637 GeV/c.

Spin-transfer observables for p p-->Lambda Lambda have been measured using a transversely polarized frozen-spin target and a beam momentum of 1.637 GeV/c. Current models of the reaction near threshold are in good agreement with existing measurements performed with unpolarized particles in the initial state but produce conflicting predictions for the spin-transfer observables Dnn and Knn (the normal-to-normal depolarization and polarization transfer), which are measurable only with polarized target or beam. Measurements of Dnn and Knn presented here are found to be in disagreement with predictions from these models.

XAFS studies of gold and silver-gold nanoparticles in aqueous solutions.

The x-ray absorption fine structure (XAFS) of colloidal Au and Au/Ag nanoparticles (3.5nm and 20nm mean diameter) in an aqueous solution has been investigated. Size dependent alloying was observed upon deposition of Ag on Au core. Ag forms distinct layers around the 20 nm Au nanoparticles. In contrast, random mixing is found for Ag deposited on 3.5nm Au particles.

XAFS and X-ray reflectivity study of III-V compound native oxide/GaAs interfaces.

Fluorescence-mode XAFS has been used to study the local environment about chosen atomic species such as Ga and As in bulk oxide Al(1-x)Ga(x)As (x=0.96) and at the interface between thin (300 A) oxidized Al(1-x)Ga(x)As (x=0.94) film and GaAs substrate in total external-reflection mode. X-ray reflectivity experiments have also been employed to investigate the density profile of the oxide film on a GaAs substrate revealing the density profile as a function of depth. It is important to find out how the As is incorporated at the interface, the interfacial strain, and related local structural parameters for understanding that may be central in developing high performance III-V MOSFET devices.

XAFS determination of the bacterial cell wall functional groups responsible for complexation of Cd and U as a function of pH.

Bacteria, which are ubiquitous in near-surface geologic systems, can affect the distribution and fate of metals in these systems through adsorption reactions between the metals and bacterial cell walls. Recently, Fein et al. (1997) developed a chemical equilibrium approach to quantify metal adsorption onto cell walls, treating the sorption as a surface complexation phenomenon. However, such models are based on circumstantial bulk adsorption evidence only, and the nature and mechanism of metal binding to cell walls for each metal system have not been determined spectroscopically. The results of XAFS measurements at the Cd K-edge and U L3-edge on Bacillus subtilis exposed to these elements show that, at low pH, U binds to phosphoryl groups while Cd binds to carboxyl functional groups.

Noncardiac surgery in individuals with coronary heart disease.

Atherosclerosis is a pathological condition of the coronary arteries clinically manifested as cardiovascular disease, the major cause of death in the industrialized world. Coronary heart disease (CHD) and cerebrovascular disease (CVD), both of which are atherosclerotic diseases, cause more death, disability, and economic loss in the United States than any other disease.

X-ray absorption fine-structure spectroscopy studies of Fe sites in natural human neuromelanin and synthetic analogues.

X-ray absorption fine-structure spectroscopy is used to study the local environment of the iron site in natural (human) neuromelanin extracted from substantia nigra tissue and in various synthetic neuromelanins. All the materials show Fe centered in a nearest neighbor sixfold (distorted) oxygen octahedron; the Fe-O distances, while slightly different in the natural and synthetic neuromelanin, are both approximately 2.0 A. Appreciable differences arise, however, in the second (and higher) coordination shells. In this case the synthetic melanin has the four planar oxygens bound to carbon rings with Fe-C distances of approximately 2.82 and 4.13 A; the human sample does not show the 2.82 A link but instead indicates a double shell at approximately 3.45 and 3.78 A.

Psychological distress among survivors of burn injury: the role of outcome expectations and perceptions of importance.

This study examined factors associated with psychologic distress among survivors of burn injury. The study tested hypotheses derived from Scheier and Carver's model of behavioral self-regulation and focused on two primary predictor variables: expectations concerning rehabilitative outcomes and the importance attached to those outcomes. The study used a cross-sectional research design. Two hundred sixteen people who had sustained major or moderate thermal burn injuries within 2 years of study entry served as subjects. Data were collected via mailed questionnaire and chart review. Consistent with study hypotheses, we found that participants who had low expectations for further improvement but who attached high importance to the need for improvement exhibited the most psychologic distress. Study findings lend support to Scheier and Carver's model and suggest that application of this model within the context of burn rehabilitation may increase our understanding of the rehabilitation process. Directions for future theory-based research are discussed.

Ceramic thin-film formation on functionalized interfaces through biomimetic processing.

Processing routes have been developed for the production of thin ceramic films through precipitation from aqueous solutions. The techniques are based on crystal nucleation and growth onto functionalized interfaces. Surface functionalization routes have been developed by the mimicking of schemes used by organisms to produce complex ceramic composites such as teeth, bones, and shells. High-quality, dense polycrystalline films of oxides, hydroxides, and sulfides have now been prepared from "biomimetic" synthesis techniques. Ceramic films can be synthesized on plastics and other materials at temperatures below 100 degrees C. As a low-temperature process in which water rather than organic solvents is used, this synthesis is environmentally benign. Nanocrystalline ceramics can be produced, sometimes with preferred crystallite orientation. The direct deposition of high-resolution patterned films has also been demonstrated. The process is well suited to the production of organic-inorganic composites.

Measuring health status among survivors of burn injury: revisions of the Burn Specific Health Scale.

This study examined the reliability of a revised version of the Burn Specific Health Scale (BSHS). Two hundred fifty-four former patients recruited from eight burn centers in the southeastern United States participated in the study. Data were collected via chart review and mailed questionnaire. Factor analyses were used to identify seven subscales containing a total of 31 items. Subsequent analyses provided strong support for the reliability and validity of the revised measure. Each subscale exhibited a high level of reliability (Cronbach's alpha ranged from 0.82 to 0.94). Each subscale also correlated in a predictable manner with measures used for validation. The revised measure should improve the ability of both researchers and clinicians to assess the impact of non-fatal burn injury accurately and comprehensively.

The impact of burn injury: a preliminary investigation.

Thirty-eight individuals who had been previously hospitalized for burn injuries were interviewed about the problems that they had experienced as a result of their injuries, their rehabilitation goals, and factors that they believed had influenced either the rate or extent of their recovery. The problems that were most frequently mentioned by participants were compared with problem areas that are covered by the Burn-Specific Health scale, which is a standardized measure designed to assess the impact of burn injury. Our findings suggest that although many problem areas are well covered by the Burn-Specific Health scale, other areas are covered less well. Thus more work is needed to refine the scale to capture more fully the wide variety of problems that are experienced by survivors of burn injuries. In general, patients' rehabilitation goals reflected the types of problems they experienced. Support from health care providers was the most frequently mentioned facilitator to recovery, which emphasizes the importance of the patient-provider relationship.

Independent nonprofessionals in the community: a case history analysis of a human relations program.

For eight years a group of nonprofessional human relations trainers conducted a community-based Adult-Youth T-Group Program in a suburban community under the auspices of the Board of Education. Their history provides the material for this case analysis, which will focus on two sets of issues. One set of issues surrounds the fact that these group leaders were "independent nonprofessionals": trained but noncredentialed persons performing functions usually reserved for professionals (or performed under professional supervision) and performing them outside of institutional and professional boundaries. A second set of issues, only partially related to the first, surrounds the organizational dilemmas and social-political conflict which beset this team and the program which they conducted.

The iron-sulfur environment in rubredoxin.

The atomic environment around the iron site in the nonheme iron sulfur protein rubredoxin was studied by the extended X-ray absorption fine structure (EXAFS) technique. Within experimental error, the Fe-S bonds in oxidized Clostridium pasteurianum rubredoxin are the same as in the analogue anion [Fe(S2-o-xyl)2]-synthesized by Holm. The average Fe-S bond length is 2.267 +/- 0.003A and the root mean square deviation about this average due to structural disorder is 0.032 + 0.013 - 0.032.