180 research outputs found

    Dielectrophoretic Assembly of Carbon Nanofiber Nanoelectromechanical Devices

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    We report a technique for the assembly of bottom-up nanomechanical devices. This technique employs the dielectrophoretic manipulation of nanostructures within a multiple layer lithography process. Mechanical resonators were specifically produced by assembling and clamping tubular carbon fibers onto prefabricated pads. Our preliminary results showed that an assembled cantilevered fiber with length L = 5 µm and width of W = 180 nm possessed a resonant frequency of f = 1.17 MHz. A shorter L = 3-µm-long singly clamped resonator of similar width showed a resonance of f = 3.12 MHz. This frequency range is in agreement with the low gigapascal bending moduli previously reported for carbon structures showing extensive volume defects. This technology would allow the integration of bottom-up nanostructures with other more established fabrication processes, thus allowing the deployment of engineered nanodevices in integrated systems

    Educating the public health workforce: Issues and challenges

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    Background: In public health, as well as other health education contexts, there is increasing recognition of the transformation in public health practice and the necessity for educational providers to keep pace. Traditionally, public health education has been at the postgraduate level; however, over the past decade an upsurge in the growth of undergraduate public health degrees has taken place. Discussion: This article explores the impact of these changes on the traditional sphere of Master of Public Health programs, the range of competencies required at undergraduate and postgraduate levels, and the relevance of these changes to the public health workforce. It raises questions about the complexity of educational issues facing tertiary institutions and discusses the implications of these issues on undergraduate and postgraduate programs in public health. Conclusion: The planning and provisioning of education in public health must differentiate between the requirements of undergraduate and postgraduate students – while also addressing the changing needs of the health workforce. Within Australia, although significant research has been undertaken regarding the competencies required by postgraduate public health students, the approach is still somewhat piecemeal, and does not address undergraduate public health. This paper argues for a consistent approach to competencies that describe and differentiate entry-level and advanced practice

    Engaging Undergraduates to Solve Global Health Challenges: A New Approach Based on Bioengineering Design

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    Recent reports have highlighted the need for educational programs to prepare students for careers developing and disseminating new interventions that improve global public health. Because of its multi-disciplinary, design-centered nature, the field of Biomedical Engineering can play an important role in meeting this challenge. This article describes a new program at Rice University to give undergraduate students from all disciplines a broad background in bioengineering and global health and provides an initial assessment of program impact. Working in partnership with health care providers in developing countries, students in the Beyond Traditional Borders (BTB) initiative learn about health challenges of the poor and put this knowledge to work immediately, using the engineering design process as a framework to formulate solutions to complex global health challenges. Beginning with a freshman design project and continuing through a capstone senior design course, the BTB curriculum uses challenges provided by partners in the developing world to teach students to integrate perspectives from multiple disciplines, and to develop leadership, communication, and teamwork skills. Exceptional students implement their designs under the guidance of clinicians through summer international internships. Since 2006, 333 students have designed more than 40 technologies and educational programs; 28 have been implemented in sub-Saharan Africa, Latin America, the Caribbean, southeast Asia, and the United States. More than 18,000 people have benefited from these designs. 95% of alumni who completed an international internship reported that participation in the program changed or strengthened their career plans to include a focus on global health medicine, research, and/or policy. Empowering students to use bioengineering design to address real problems is an effective way to teach the new generation of leaders needed to solve global health challenges

    Clinical Utilities of Peripheral Blood Gene Expression Profiling in the Management of Cardiac Transplant Patients

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    Cardiac allografts induce host immune responses that lead to endomyocardial tissue injury and progressive graft dysfunction. Inflammatory cell infiltration and myocyte damage characterize acute cellular rejection (ACR) that presents episodically in either a subclinical or symptom-associated manner. Sampling of the endomyocardium by transvenous biopsy enables pathologic grading using light microscopic criteria to distinguish severity based on the focality or diffuseness of inflammation and associated myocyte injury. Monitoring for ACR utilizes endomyocardial biopsy in conjunction with history and physical examination and assessment of allograft function by echocardiography. However, procedural and interpretive issues limit the diagnostic certainty provided by endomyocardial biopsy. The dynamic profiling of genes expressed by peripheral blood mononuclear cells (PBMCs) enables quantitative assessments of intracellular mRNA whose levels fluctuate during systemic alloimmune responses. Gene expression profiling of PBMCs using a multi-gene ACR classifier enables the AlloMap® molecular expression test to distinguish moderate to severe ACR (p = 0.0018) in heart transplant patients. The AlloMap test provides molecular insights into a patient's risk for ACR by distilling the aggregate expression levels of its informative genes into a single score on a scale of 0 to 40. The selection of a score as a threshold value for clinical decision-making is based on its associated negative predictive value (NPV), which ranges from 98 to 99% for values in three post-transplant periods: >2 to ≤6 months, > 6to ≤ 12 months, and >12 months. Scores below the threshold value rule out ACR, while those above suggest increased ACR risk. Incorporating the AlloMap test into immunomonitoring protocols provides an opportunity for clinicians to enhance patient care and to define its role in immunodiagnostic strategies to optimize the clinical outcomes of heart transplant recipients. This summary highlights the concepts presented in an invited presentation at a conference focused on Immunodiagnostics and Immunomonitoring: From Research to Clinic, in San Diego, CA on November 7, 2006

    Is it possible to diagnose the therapeutic adherence of patients with COPD in clinical practice? A cohort study

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    <p>Abstract</p> <p>Background</p> <p>Therapeutic adherence of patients with chronic obstructive pulmonary disease (COPD) is poor. It is therefore necessary to determine the magnitude of non-adherence to develop strategies to correct this behaviour. The purpose of this study was to analyse the diagnostic validity of indirect adherence methods.</p> <p>Methods</p> <p>Sample: 195 COPD patients undergoing scheduled inhaled treatment attending 5 Primary Care Centres of Malaga, Spain. Variables: Sociodemographic profile, illness data, spirometry, quality of life (St. George Respiratory Questionnaire: SGRQ), and inhaled medication counting (count of dose/pill or electronic monitoring) were collected. The patient's knowledge of COPD (Batalla test:BT),their attitude towards treatment (Morisky-Green test: MGT) and their self-reported therapeutic adherence (Haynes-Sackett test: HST) were used as methods of evaluating adherence. The follow-up consisted four visits over one year (the recruitment visit: V0; and after 1 month:V1; 6 months:V2; and 1 year:V3).</p> <p>Results</p> <p>The mean age was 69.59 (95% CI, 68.29-70.89) years old and 93.8% were male. Other findings included: 85.4% had a low educational level, 23.6% were smokers, 71.5% mild-moderate COPD stage with a FEV1 = 56.86 (SD = 18.85); exacerbations per year = 1.41(95% CI, 1-1.8). The total SGRQ score was 44.96 (95% CI, 42.46-47.46), showing a mild self-perceived impairment in health. The prevalence of adherence (dose/pill count) was 68.1% (95% CI, 60.9-75.3) at V1, 80% (95% CI, 73-87) at V2 and 84% (95% CI, 77.9) at V3. The MGT showed a specificity of 67.34% at V1, 76.19% at V2 and 69.62% at V3. The sensitivity was 53.33% at V1, 66.66% at V2 and 33.33% at V3.The BT showed a specificity of 55.1% at V1, 70.23% at V2 and 67.09% at V3. The sensitivity was 68.88% at V1, 71.43% at V2 and 46.66% at V3. Considering both tests together, the specificity was 86.73% at V1, 94.04% at V2 and 92.49% at V3 and the sensitivity was 37.77% at V1, 47.62% at V2 and 13.3% at V3.</p> <p>Conclusions</p> <p>The prevalence of treatment adherence changes over time. Indirect methods (dose/pill count and self-reported) can be useful to detect non-adherence in COPD patients. The combination of MGT and BT is the best approach to test self-reported adherence.</p
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