Design and manufacture of low cost vaccine cooler

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (p. 58).Vaccines are very sensitive to temperature, needing to be held between 2 and 80°C to maintain potency. In developing countries where electricity and fuel supplies are unreliable, many vaccines are ruined due to thermal exposure. These are also the locations where vaccines are needed the most, yet often many of the vaccines given are ineffective. Long holdover vaccine coolers are designed to maintain a proper internal temperature during long periods of power loss. The most prevalent technology is the ice-lined cooler, but in the field these often have problem with freezing the vaccines. A vaccine cooler was designed that modifies the ice-jacket idea by separating the ice compartment and the vaccine chamber, connecting them through a heat transfer regulating device. The objective of this research is to design and prototype the heat transfer regulating device. After several design iterations a cooling loop filled with R-134a made of 1/8 piping, a 0.055 in ID capillary, and a Clippard normally-closed valve was combined with a modified car thermostat, using peanut oil as its working fluid, to create a thermosyphon type heat transfer device with a safety shutoff to prevent freezing. The prototype was manufactured and tested. It was found that with the proper amount of working fluid, it is possible to run the cooling loop at 4°C and pull heat from the vaccine chamber side to the ice. The peanut oil thermostat was tested and was found to open at a slightly lower temperature than expected, 2.5°C, but still within range. These results indicate that the concept is viable and should be tested in the vaccine cooler.by Cynthia D. Walker.S.B

Differential Regulation of Growth-Promoting Signalling Pathways by E-Cadherin

Background: Despite the well-documented association between loss of E-cadherin and carcinogenesis, as well as the link between restoration of its expression and suppression of proliferation in carcinoma cells, the ability of E-cadherin to modulate growth-promoting cell signalling in normal epithelial cells is less well understood and frequently contradictory. The potential for E-cadherin to co-ordinate different proliferation-associated signalling pathways has yet to be fully explored. Methodology/Principal Findings: Using a normal human urothelial (NHU) cell culture system and following a calcium-switch approach, we demonstrate that the stability of NHU cell-cell contacts differentially regulates the Epidermal Growth Factor Receptor (EGFR)/Extracellular Signal-Regulated Kinase (ERK) and Phosphatidylinositol 3-Kinase (PI3-K)/AKT pathways. We show that stable cell contacts down-modulate the EGFR/ERK pathway, whilst inducing PI3-K/AKT activity, which transiently enhances cell growth at low density. Functional inactivation of E-cadherin interferes with the capacity of NHU cells to form stable calcium-mediated contacts, attenuates E-cadherin-mediated PI3-K/AKT induction and enhances NHU cell proliferation by allowing de-repression of the EGFR/ERK pathway and constitutive activation of beta-catenin-TCF signalling. Conclusions/Significance: Our findings provide evidence that E-cadherin can differentially and concurrently regulate specific growth-related signalling pathways in a context-specific fashion, with direct, functional consequences for cell proliferation and population growth. Our observations not only reveal a novel, complex role for E-cadherin in normal epithelial cell homeostasis and tissue regeneration, but also provide the basis for a more complete understanding of the consequences of E-cadherin loss on malignant transformation

Age-related biomarkers can be modulated by diet in the rat

This study seeks to establish the normal serum concentrations of biochemical markers related to nutrition, inflammation and disease, and to investigate how the levels change with age and diet in the rat. To this end, we fed rats from weaning on three diets differing in their protein, carbohydrate and fatty acid content. The diets consisted of a control, nutritionally balanced diet, this same diet supplemented with 10% (wt/wt) beef tallow, and a diet that was high in fat and carbohydrate and low in protein. Blood samples from rats at two different ages, 3 months and 12 months, were then analysed. In control rats, with advancing age there was a general decrease in potassium, iron and serum albumin concentrations and in the activities of aspartate aminotransferase and alanine aminotransferase, and an increase in total and HDL cholesterol. These changes were modulated by diet: many of the age-related changes (serum concentrations of potassium, iron and cholesterol, and liver enzyme activities) were not observed in animals eating the high fat diet. In contrast, the high carbohydrate, high fat, low protein diet-fed animals showed several additional changes (serum concentrations of sodium, urea, creatinine and TG, and activity of alkaline phosphatase) that can be related to kidney, liver and cardiovascular health

Satisfaction with Care among Residents and Families in a Long-Term and Complex Continuing Care Organization

This article looks at one organization’s implementation of a satisfaction survey for all of its residents. It also explores how satisfaction ratings vary between complex continuing care (CCC) and long-term care (LTC) residents between residents with and without dementia. Satisfaction with care at St. Joseph’s Health Centre (SJHC) Guelph was measured during the fall and winter of 2004/2005. A total of 107 residents and patients from both LTC and CCC were interviewed and 141 family members returned mailed surveys. Overall quality of care was rated highly by both residents and families. There were no statistically significant differences comparing LTC and CCC residents and only one comparing those with and without dementia. Within the area of medical care, 57.7% of residents with dementia compared to 78.0% of residents without dementia agreed they received therapy when needed (p=.03). This information has been very valuable to SJHC staff and administrators as they strive to improve their quality of care. The project also highlights the important work that can be achieved through collaborations between researchers and health care providers

Do Word Of Mouth And Advertising Messages On Social Networks Influence The Purchasing Behavior Of College Students?

Many online advertisers are exploring the use of Internet social networking to build brand awareness and loyalty. Social networking is particularly popular among the younger, 15-24 year- old generation, who is more computer savvy and spends more time on the Internet than adults. While this generation has substantial potential, they also represent a challenge to advertisers. This group is notoriously skeptical of being “advertised at.” They expect a more personal, interactive experience. The purpose of this research is to determine which types of social networks are used most by college students and what types of online marketing impact their purchasing choices. In carrying out this research, the following research questions were addressed: which social networks are used most by college students; do factors such as student and/or parent income, student age, classification, gender, marital status, or employment status influence use of social networks; do ads on social networks impact purchasing decisions; does advice from other users of social networks impact purchasing decisions; and do online games, scavenger hunts, and contests influence purchasing decisions? The research provides a better understanding of social network use and provides insight into effective online advertising to college students

Widening participation and the role of social motivation in students' transitional experiences in higher education

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The cost-effectiveness of nivolumab monotherapy for the treatment of advanced melanoma patients in England

Background: Nivolumab was the first programmed death receptor 1 (PD-1) immune checkpoint inhibitor to demonstrate long-term survival benefit in a clinical trial setting for advanced melanoma patients. Objective: To evaluate the cost effectiveness of nivolumab monotherapy for the treatment of advanced melanoma patients in England. Methods: A Markov state-transition model was developed to estimate the lifetime costs and benefits of nivolumab versus ipilimumab and dacarbazine for BRAF mutation-negative patients and versus ipilimumab, dabrafenib, and vemurafenib for BRAF mutation-positive patients. Covariate-adjusted parametric curves for time to progression, pre-progression survival, and post-progression survival were fitted based on patient-level data from two trials and long-term ipilimumab survival data. Indirect treatment comparisons between nivolumab, ipilimumab, and dacarbazine were informed by these covariate-adjusted parametric curves, controlling for differences in patient characteristics. Kaplan–Meier data from the literature were digitised and used to fit progression-free and overall survival curves for dabrafenib and vemurafenib. Patient utilities and resource use data were based on trial data or the literature. Patients are assumed to receive nivolumab until there is no further clinical benefit, assumed to be the first of progressive disease, unacceptable toxicity, or 2 years of treatment. Results: Nivolumab is the most cost-effective treatment option in BRAF mutation-negative and mutation-positive patients, with incremental cost-effectiveness ratios of £24,483 and £17,362 per quality-adjusted life year, respectively. The model results are most sensitive to assumptions regarding treatment duration for nivolumab and the parameters of the fitted parametric survival curves. Conclusions: Nivolumab is a cost-effective treatment for advanced melanoma patients in England

Reasons why Thai patients with chronic kidney disease use or do not use herbal and dietary supplements

BACKGROUND:Despite a high prevalence of herbal and dietary supplement use (HDS) in pre-dialysis patients, the reasons are unknown as to why they decide to use HDS. Objectives of the cross-sectional and qualitative studies were to determine reasons for the use and non-use of HDS in Thai patients with chronic kidney disease (CKD).METHODS:This prospective study recruited 421 patients with stage 3-5 CKD from two kidney clinics in Thailand, and 357 were followed up regarding their HDS use over 12 months. Patients receiving renal replacement therapy at baseline were excluded. Participants were interviewed at baseline and in the twelfth month regarding their HDS use, and reasons for their use or non-use of HDS. Among HDS users, 16 patients were enrolled in a qualitative study and were interviewed using eight-open ended questions about reasons for HDS use. Descriptive and thematic analyses were performed.RESULTS:Thirty-four percent of patients with CKD consistently used HDS over the 12 months and 17% of all patients intermittently took them during the follow-up period. At baseline, family or friends' recommendation was the most common reason for HDS use (35%), followed by having a perception of benefits from using HDS (24%). During the follow-up period, perceived benefits of HDS was a frequently reported reason for either continuing with HDS use (85%) or starting to use HDS (65%). Negative experience from using HDS influenced patients to stop using them (19%). Although the main reason for non-use of HDS was trust in a doctor or effectiveness of conventional medicine (32%), doubt about the benefits from HDS or concerns about negative effects were frequently reported reasons for non-use (23%). Doctor's recommendations to avoid using HDS were the main influence for non-users (19%) and for those who had stopped using HDS (23%). The media and patients' social network had an impact on HDS use.CONCLUSIONS:Patients who perceived benefits from HDS use were more likely to use HDS, whilst non-users had negative attitudes towards HDS. Health professionals therefore should educate patients and their relatives about the risks and benefits from using HD