Vibrational-mechanical properties of the highly-mismatched Cd1-xBexTe semiconductor alloy: experiment and ab initio calculations

The emerging CdTe-BeTe semiconductor alloy that exhibits a dramatic mismatch in bond covalency and bond stiffness clarifying its vibrational-mechanical properties is used as a benchmark to test the limits of the percolation model (PM) worked out to explain the complex Raman spectra of the related but less contrasted Zn1-xBex-chalcogenides. The test is done by way of experiment ([Formula: see text]), combining Raman scattering with X-ray diffraction at high pressure, and ab initio calculations ([Formula: see text] ~ 0-0.5; [Formula: see text]~1). The (macroscopic) bulk modulus [Formula: see text] drops below the CdTe value on minor Be incorporation, at variance with a linear [Formula: see text] versus [Formula: see text] increase predicted ab initio, thus hinting at large anharmonic effects in the real crystal. Yet, no anomaly occurs at the (microscopic) bond scale as the regular bimodal PM-type Raman signal predicted ab initio for Be-Te in minority ([Formula: see text]~0, 0.5) is barely detected experimentally. At large Be content ([Formula: see text]~1), the same bimodal signal relaxes all the way down to inversion, an unprecedented case. However, specific pressure dependencies of the regular ([Formula: see text]~0, 0.5) and inverted ([Formula: see text]~1) Be-Te Raman doublets are in line with the predictions of the PM. Hence, the PM applies as such to Cd1-xBexTe without further refinement, albeit in a "relaxed" form. This enhances the model's validity as a generic descriptor of phonons in alloys.

Illustrative case using the RISK21 roadmap and matrix: prioritization for evaluation of chemicals found in drinking water

The HESI-led RISK21 effort has developed a framework supporting the use of twenty-first century technology in obtaining and using information for chemical risk assessment. This framework represents a problem formulation-based, exposure-driven, tiered data acquisition approach that leads to an informed decision on human health safety to be made when sufficient evidence is available. It provides a transparent and consistent approach to evaluate information in order to maximize the ability of assessments to inform decisions and to optimize the use of resources. To demonstrate the application of the framework's roadmap and matrix, this case study evaluates a large number of chemicals that could be present in drinking water. The focus is to prioritize which of these should be considered for human health risk as individual contaminants. The example evaluates 20 potential drinking water contaminants, using the tiered RISK21 approach in combination with graphical representation of information at each step, using the RISK21 matrix. Utilizing the framework, 11 of the 20 chemicals were assigned low priority based on available exposure data alone, which demonstrated that exposure was extremely low. The remaining nine chemicals were further evaluated, using refined estimates of toxicity based on readily available data, with three deemed high priority for further evaluation. In the present case study, it was determined that the greatest value of additional information would be from improved exposure models and not from additional hazard characterization.

Selective D2-40 lymphatic endothelium immunoreactivity in developing human fetal skin appendages

D2-40 is a novel monoclonal antibody that recognizes a 40,000 Da O-linked sialoglycoprotein podoplanin. Although its use is becoming more common, little work has been done with human foetuses. We initiated an evaluation of D2-40 antibody immunoreactivity in developing cutaneous adnexa of human fetuses at various gestational ages. Starting from a retrospective cohort of 1,098 human fetal autopsies we identified and selected a total of 48 fetuses ranging from the 12th week gestational age to term appropriate for this study. We demonstrated that the gems of the hair follicles were D2-40 negative in fetuses from the 12th to 15th week gestation, positive in fetuses between the 16th and 20th week of gestation, negative in fetuses from the 21st week gestation to term. Normal adult controls were also negative. This is the first report to demonstrate intense D2-40 immunoreactivity in the gems of hair follicles of developing human skin.

Generation of reactive oxygen species by endothelial and smooth muscle cells: influence of hyperglycemia and metformin

There is evidence that reactive oxygen intermediates (ROI) play an important role in the pathogenesis of vascular complications in diabetes. On the other hand, metformin, one of the most often used antidiabetic compounds has not only been shown to reduce the risk for vascular complications, but in addition these protective effects are largely independent of its well-known antihyperglycemic action. Therefore, to explain the vasculoprotective effects of metformin, a direct antioxidative action of this compound has been suggested. We show here that human endothelial cells (HUVEC) generate ROI not only in response to high glucose (30 mmol/l glucose), but also in response to palmitic acid, and advanced glycation end-products (carboxymethyllysine and S100 proteins). Metformin inhibited the production of ROI in response to all these stimuli. By double staining-dichlorofluorescein as marker of ROI and Mitotracker CMH-Ros for mitochondria-the mechanism of ROI generation was analyzed in more detail in smooth muscle cells. Our data suggest that ROI are generated by uncoupling of the mitochondrial respiratory chain as well as by activation of the cytosolic NADPH-oxidase. A complete inhibition of ROI generation is only achieved by simultaneous inhibition of the mitochondrial electron flux (theonyltrifluoroacetone) and NADPH-oxidase (apocynin). Our data suggest that the various processes contributing to generation of ROI are closely linked. Activation of AMP kinase may represent an important mechanism to understand the antioxidative effects of metformin on the mitochondrial and cytosolic generation of ROI.

Domains of nursing intervention after sudden cardiac arrest and automatic internal cardioverter defibrillator implantation

PURPOSE

The purpose of the study was to explore individual and family experiences after sudden cardiac arrest and automatic internal cardioverter defibrillator implantation during the first year of recovery. This report specifically addresses the domains of concern expressed and helpful strategies used by participants that are relevant to the development of future intervention programs.

DESIGN

A grounded theory approach was used to gain an understanding of areas of concern of sudden cardiac arrest survivors and families that could be used when designing future nursing interventions. Semistructured interviews were conducted with both sudden cardiac arrest survivors and 1 family member each at 5 points during the first year of recovery (hospitalization; 1, 3, 6, and 12 months after hospitalization). Participants were asked to identify those specific areas that most concerned them and that they would like assistance with during the first year. A total of 150 interviews were conducted with 176 hours of data generated.

SETTING

The study focused on 10 northwest urban community medical centers and participants' homes within a 50-mile driving distance from the medical centers.

SAMPLE

The sample included 15 first-time sudden cardiac arrest survivors (13 men and 2 women) and 1 family member each between the ages of 31 and 72 years.

RESULTS

Domains of concern identified by participants that can be used to design future nursing intervention programs included preventive care, dealing with automatic internal cardioverter defibrillator shocks, emotional challenges, physical changes, activities of daily living, partner relationships, and dealing with health care providers. Suggestions of helpful strategies used by participants during the first year are outlined.

IMPLICATIONS

Domains of concern and helpful strategies identified by participants provide a framework for the development and testing of nursing intervention programs to enhance recovery following sudden cardiac arrest for survivors and their families.

Sample housing for high-energy Compton measurements

In order to obtain reliable Compton spectra using high-energy photons, the scattered beam must be free of parasitic photons, because of the weakness of the double-differential inelastic cross section. The purpose of the device presented in this paper is to remove photons scattered by air, the sample holder or any other stopper. It has been tested on ESRF beamline 2, which is devoted to materials science.

Relocating adult day care: its impact on persons with dementia

1. Adult day care centers may be housed in temporary locations as they are being developed or they may be forced to relocate during their existence; this may increase disorientation and other behavior changes in clients. 2. Consistency reduces disorientation and behavioral management difficulties; this can be achieved by low staff turnover, predictable daily routines, and a stable environment. 3. this study concluded that no permanent, harmful effects resulted from the relocation of the day care center. 4. It is important for staff to focus on observing the clients' behaviors and attending to their individual needs when relocating persons with dementia.