A facile one step route that introduces functionality to polymer powders for laser sintering.

Laser Sintering (LS) is a type of Additive Manufacturing (AM) exploiting laser processing of polymeric particles to produce 3D objects. Because of its ease of processability and thermo-physical properties, polyamide-12 (PA-12) represents ~95% of the polymeric materials used in LS. This constrains the functionality of the items produced, including limited available colours. Moreover, PA-12 objects tend to biofoul in wet environments. Therefore, a key challenge is to develop an inexpensive route to introduce desirable functionality to PA-12. We report a facile, clean, and scalable approach to modification of PA-12, exploiting supercritical carbon dioxide (scCO2) and free radical polymerizations to yield functionalised PA-12 materials. These can be easily printed using commercial apparatus. We demonstrate the potential by creating coloured PA-12 materials and show that the same approach can be utilized to create anti-biofouling objects. Our approach to functionalise materials could open significant new applications for AM.

Physicians and Reform: The State of The Art and The Challenge to Physicians.

Within the context of medical reformation outlined by Hoffman in a series of three papers in South Dakota Medicine and the challenge of legislation involving the independent practice of advanced practice nurses, we undertook two surveys of physicians and patients. We wanted to better understand physicians' attitudes toward certain opportunities for reform and how they conformed to the viewpoints of our patients. We found that, at least with respect to nurse practice legislation, physicians' perceptions were at odds with their patients over questions of access and quality. Moreover, we found attitudinal differences among physicians depending upon whether they were independent or affiliated with a health care system and whether they were primary care physicians or specialists. We concluded that physicians do not yet share the common understanding necessary to advocate for a principle of medical practice encompassing the core needs of patients and the spectrum of caregivers.

Outcomes by race and etiology of patients with left ventricular systolic dysfunction.

Previous studies have shown that blacks have worse long-term outcomes than whites who have systolic heart failure. The reasons for these racial differences remain unclear. We investigated the effect of race and etiology of heart failure on outcomes of patients who had left ventricular (LV) systolic dysfunction. We studied records of 1,977 patients (27% black) who underwent cardiac catheterization who had New York Heart Association class II to IV symptoms and a LV ejection fraction <40%. Adjusted Cox's proportional hazards regression models were examined for the end points of mortality, rehospitalization, and a composite of the 2. Black versus white patients were younger (median age 56 vs 63 years, p <0.01), more often were women (49% vs 33%, p <0.01), had diabetes (37% vs 31%, p = 0.02), and hypertension (75% vs 56%, p <0.01). Black patients were less likely to have significant coronary artery disease by angiography (41% vs 69%, p <0.01). Race was not an independent predictor of mortality (hazard ratio 1.09, 95% confidence interval 0.93 to 1.28, p = 0.27). After adjusted survival curves were stratified by race and etiology, the estimates indicated that among those patients who had nonischemic LV dysfunction, blacks appeared to have worse survival than whites. Thus, we found no racial differences in the long-term mortality risk of patients who had symptomatic LV systolic dysfunction. In conclusion, after stratifying by ischemic and nonischemic etiologies, we found decreased survival in blacks who had a nonischemic etiology compared with whites. There were no racial differences in rehospitalization between patients who had ischemic LV systolic dysfunction and those who did not.

Racial differences in the outcomes of patients with diastolic heart failure.

BACKGROUND: More than half of all patients with congestive heart failure have preserved left ventricular systolic function. This is particularly common in African American patients, yet there have been few studies examining the long-term natural history of this disorder in African-American and white patients. METHODS: We studied 2740 white and 563 African American patients with class II to IV symptoms and preserved systolic function (ejection fraction >40) identified in the Duke Cardiovascular Databank from 1984 to 1996. Unadjusted and adjusted 5-year survival rate comparisons were performed with Kaplan-Meier and Cox proportional hazards models, respectively. RESULTS: The 5-year survival rates were 68% for African American patients and 70% for white patients (P =.55). However, after adjusting for known risk factors, African American patients had a significantly higher mortality risk than white patients (hazard ratio [HR], 1.34; 95% CI, 1.13-1.60). This racial difference in survival rate was most prominent in patients with a non-ischemic etiology (HR, 1.6; 95% CI, 1.2-2.0) as compared with patients with ischemic heart failure (HR, 1.1; 95% CI, 0.9-1.4). CONCLUSION: Among patients with heart failure and preserved left ventricular systolic function, African American patients have a worse long-term prognosis than white patients. These results are important because of the prevalence of this condition in African American patients and their potential heterogeneous response to many heart failure therapies.

Staphylococcus aureus pericardial abscess in a patient with liver cirrhosis: case report.

Pericardial abscess is a rare complication of Staphylococcus aureus bacteremia. We report the case of a 40-year-old man with hepatitis C and liver cirrhosis who presented with high-grade fever and chest pain. Transthoracic echocardiography showed a pericardial mass and computed tomographic scanning and transesophageal echocardiography confirmed the presence of a loculated fluid collection. His illness persisted despite i.v. antibiotics and video-assisted thoracoscopic drainage. The patient was cured after surgical drainage and pericardiectomy.

The influence of left ventricular hypertrophy on survival in patients with coronary artery disease: do race and gender matter?

OBJECTIVES: We sought to determine the overall prognostic importance of left ventricular hypertrophy (LVH) among patients with coronary artery disease (CAD), as well as to determine whether this risk varies as a function of race or gender. BACKGROUND: Left ventricular hypertrophy is more prevalent among blacks and women than their counterparts. Blacks and women also have higher mortality with coronary disease. METHODS: We studied records of 2,461 patients (19% black, 42% women) diagnosed with CAD at cardiac catheterization between 1990 and 1998 from a single academic center. Left ventricular hypertrophy was defined using standard echocardiographic measures. Cox proportional hazards models were used for adjusted survival analyses. Mean patient follow-up was three years. RESULTS: Patients with LVH were older (68 vs. 65 years, p < 0.01), more often women (54% vs. 36%, p < 0.01), and black (25% vs. 16%, p < 0.01), and had higher unadjusted three-year mortality rates than patients without LVH (42% vs. 34%, p < 0.01). Left ventricular hypertrophy remained an independent predictor of mortality after adjusting for other clinical risk factors (hazard ratio 1.56, 95% confidence interval 1.35 to 1.80) with prognostic importance equivalent to that of left ventricular ejection fraction. Although the relative risk of LVH did not vary by race or gender, the attributable risk of LVH was greater in blacks and women. CONCLUSIONS: Clinicians should consider the prognostic importance of LVH when assessing risk in patients with CAD. Because LVH is more common among black and women patients with CAD, it partially accounts for racial and gender differences in survival.

Racial differences in health-related beliefs, attitudes, and experiences of VA cardiac patients: scale development and application.

OBJECTIVES: To deternine whether there are racial differences in patients' health-related attitudes, beliefs, and experiences regarding invasive cardiac procedures, and to develop psychometrically and conceptually valid scales and single items to assess these dimensions. METHODS: A survey was designed and administered to 854 white and black patients with ischemic heart disease at five VA medical centers. Patients were queried about the domains proposed to be important to treatment decision making by the Health Decision Model: sociodemographic characteristics, social interactions, health care experiences, patient preferences for care, knowledge about diseases and potential treatments, and health beliefs. Using multitrait analysis, the psychometric properties of scales assessing these domains were examined. It was then assessed whether there were racial differences in scale or individual item scores using chi2 and t test analyses. RESULTS: The analyses yielded eight psychometrically valid scales: disease severity, patient evaluation of physician's interpersonal style, patient evaluations of VA care, satisfaction with treatment decision making, perceived urgency of catheterization, vulnerability to catheterization, bodily impact of catheterization, and attitudes toward religion. There were only racial differences on mean scores for the latter scale. Individual item analyses indicated that black patients were less likely to have been encouraged by friends or family to have cardiac catheterization, and had less personal or familial experiences with this or other surgical procedures. In contrast to expectations, white patients were more likely to be skeptical of medical care. CONCLUSIONS: The multiple dimensions of white and black patients' health-related attitudes, beliefs, and experiences were examined, and few differences were found. These results suggest that racial differences in patients' attitudes, beliefs, and experiences are not a likely source of racial disparities in cardiac care. Future research will examine the association of beliefs, attitudes and experiences with actual use of invasive cardiac procedures.