A Multi-Analytical Investigation of the Hydrogel Phase

In this thesis are discussed aspects in which certain chemical and physical behaviour of relevance to abiogenesis, the origins of life, changes when compared between the aqueous phase and a mineral hydrogel phase. The significance of this work is based on observations that the cytosolic medium within all biological cells is better thought of as a hydrogel rather than aqueous. Chapter 1 provides an introduction to the fundamental principles of interest to this work, discusses hydrogels, their synthesis, properties and especially their potential role in abiogenesis. Also discussed are the concepts of amphiphilic self-assembly which is an important process examined in this thesis, and then concludes with some discussion of the analytical techniques used within the project. Chapter 2 describes the surface analysis of two different concentrations of silica hydrogels along with methods for isolating the silica matrix and surface analyses using electron microscopy (SEM) and associated techniques (BET, EDX). Chapter 3 outlines critical micelle concentration (CMC) measurements of the model amphiphile, sodium dodecyl sulfate (SDS) in both the aqueous and silica hydrogel phases in the presence of various salts. Included in this salt list are simulated seawater, NaCl, Na2CO3, Na2HPO4, Na2SiO3, Na2SO4 and MgCl2. Colorimetric methods were used employing a colorimetric reporter dye (pinacyanol chloride) by UV-Vis spectrophotometry. Chapter 4 outlines related CMC measurements of SDS-alcohol mixtures (C2-OH, C6-OH, C8-OH, C10-OH, C12-OH) again in both the aqueous and silica hydrogel phase using the same method. Chapter 5 Outlines the possibility of vesicle formation of SDS-Alcoholic composites in Silica Hydrogels. Chapter 6 examines the use of two different methods to explore the gelation process within silica hydrogels and any influence of inorganic and organic additives by UV-Vis light scattering, and turbidity meter measurements. Chapter 7 contains experimental details and sample preparation from Chapters 2 to Chapter 6. Chapter 8 offers a summary, conclusion, and future work perspective on the studies reported in this thesis

A critical review on the synthesis of natural sodium alginate based composite materials: An innovative biological polymer for biomedical delivery applications

Sodium alginate (Na-Alg) is water-soluble, neutral, and linear polysaccharide. It is the derivative of alginic acid which comprises 1,4-β-d-mannuronic (M) and α-l-guluronic (G) acids and has the chemical formula (NaC6H7O6). It shows water-soluble, non-toxic, biocompatible, biodegradable, and non-immunogenic properties. It had been used for various biomedical applications, among which the most promising are drug delivery, gene delivery, wound dressing, and wound healing. For different biomedical applications, it is used in different forms with the help of new techniques. That is the reason it had been blended with different polymers. In this review article, we present a comprehensive overview of the combinations of sodium alginate with natural and synthetic polymers and their biomedical applications involving delivery systems. All the scientific/technical issues have been addressed, and we have highlighted the recent advancements

Optimizing time-series forecasts for inflation and interest rates using simulation and model averaging

Motivated by economic-theory concepts – the Fisher hypothesis and the theory of the term structure – we consider a small set of simple bivariate closed-loop time-series models for the prediction of price inflation and of long- and short-term interest rates. The set includes vector autoregressions (VAR) in levels and in differences, a cointegrated VAR and a non-linear VAR with threshold cointegration based on data from Germany, Japan, UK and the US. Following a traditional comparative evaluation of predictive accuracy, we subject all structures to a mutual validation using parametric bootstrapping. Ultimately, we utilize the recently developed technique of Mallows model averaging to explore the potential of improving upon the predictions through combinations. While the simulations confirm the traded wisdom that VARs in differences optimize one-step prediction and that error correction helps at larger horizons, the model-averaging experiments point at problems in allotting an adequate penalty for the complexity of candidate models. (Author's abstract

The headache under-response to treatment (HURT) questionnaire, an outcome measure to guide follow-up in primary care: development, psychometric evaluation and assessment of utility

Background: Headache disorders are both common and burdensome but, given the many people affected, provision of health care to all is challenging. Structured headache services based in primary care are the most efficient, equitable and cost-effective solution but place responsibility for managing most patients on health-care providers with limited training in headache care. The development of practical management aids for primary care is therefore a purpose of the Global Campaign against Headache. This manuscript presents an outcome measure, the Headache Under-Response to Treatment (HURT) questionnaire, describing its purpose, development, psychometric evaluation and assessment for clinical utility. The objective was a simple-to-use instrument that would both assess outcome and provide guidance to improving outcome, having utility across the range of headache disorders, across clinical settings and across countries and cultures. Methods: After literature review, an expert consensus group drawn from all six world regions formulated HURT through item development and item reduction using item-response theory. Using the American Migraine Prevalence and Prevention Study’s general-population respondent panel, two mailed surveys assessed the psychometric properties of HURT, comparing it with other instruments as external validators. Reliability was assessed in patients in two culturally-contrasting clinical settings: headache specialist centres in Europe (n = 159) and primary-care centres in Saudi Arabia (n = 40). Clinical utility was assessed in similar settings (Europe n = 201; Saudi Arabia n = 342). Results: The final instrument, an 8-item self-administered questionnaire, addressed headache frequency, disability, medication use and effect, patients’ perceptions of headache “control” and their understanding of their diagnoses. Psychometric evaluation revealed a two-factor model (headache frequency, disability and medication use; and medication efficacy and headache control), with scale properties apparently stable across disorders and correlating well and in the expected directions with external validators. The literature review found few instruments linking assessment to clinical advice or suggested actions: HURT appeared to fill this gap. In European specialist care, it showed utility as an outcome measure across headache disorders. In Saudi Arabian primary care, HURT (translated into Arabic) was reliable and responsive to clinical change. Conclusions: With demonstrated validity and clinical utility across disorders, cultures and settings, HURT is available for clinical and research purposes

Interest in healthy living outweighs presumed cultural norms for obesity for Ghanaian women

BACKGROUND: Cultural norms indicate that obesity reflects increased wealth and prosperity. Yet obesity is linked to serious medical illnesses. The purpose of this study was to determine if Ghanaian women would change their body image if it meant a healthier life. METHODS: A questionnaire was administered to 305 Ghanaian women waiting for clinic appointments at Korle Bu Teaching Hospital, Accra Ghana. This survey included questions on current health, selection of figural stimuli, decision making on health and social determinants and 5 questions on self-perception of health from SF-36. Anthropometric measures were taken and body mass index calculated. Women were also provided with health related information at the conclusion of the interview. RESULTS: The majority of all women surveyed would reduce their current body image if it meant that they would have an overall healthier life and reduce the risks of obesity-linked illnesses and complications. Currently obese women were significantly more likely than non-obese women to reduce their body image to reduce the risk of hypertension (OR 2.03 [1.64 – 2.51],<0.001); cardiovascular accident (OR 1.96 [1.61 – 2.38],<0.001); diabetes (OR 2.00 [1.63 – 2.44],<0.001); myocardial infarction (OR 2.27 [1.80 – 2.86],<0.001); if requested by a spouse(OR 2.64 [1.98 – 3.52],<0.001); and to improve overall health (OR 1.95 [1.60 – 2.37], <0.001). There was no association with current body image and responses to SF-36. The decision to select a new body image was not influenced by education, income, marital status or parity. Age 50 years old and less was significantly associated with the body image size reduction to reduce the risk of hypertension, diabetes, and a cardiovascular accident. CONCLUSION: The Ghanaian women interviewed in this study are interested in living a healthy life and are willing to reduce their body size to reduce the risk of obesity-linked illnesses. The target group for any interventional studies and measures to reduce obesity appears to be women age 50 and younger

Mapping the terrain: A conceptual schema for a mental health medication support service in community pharmacy

Objective: Mental health–related problems pose a serious issue for primary care, and community pharmacy could make a significant contribution, but there is a dearth of information. Methods: This article reports synthesis of the literature on mental health interventions across a range of pharmacy models, and pharmacy services in contexts beyond mental health. To best inform the design of a community pharmacy medication support intervention for mental health consumers, the literature was reported as a conceptual schema and subsequent recommendations for development, implementation and evaluation of the service. A broad conceptualisation was taken in this review. In addition to mental health and community pharmacy literature, policy/initiatives, organisational culture and change management principles, and evaluative processes were reviewed. Key words were selected and literature reviews undertaken using EMBASE, PubMed, CINAHL and Web of Science. Results: Recommendations were made around: medication support intervention design, consumer recruitment, implementation in community pharmacy and evaluation. Surprisingly, there is a scarce literature relating to mental health interventions in community pharmacy. Even so, findings from other pharmacy models and broader medicines management for chronic illness can inform development of a medication support service for mental health consumers. Key learnings include the need to expand medicines management beyond adherence with respect to both intervention design and evaluation. Conclusion: The conceptual framework is grounded in the need for programmes to be embedded within pharmacies that are part of the health system as a whole

Structured headache services as the solution to the ill-health burden of headache: 1. Rationale and description

In countries where headache services exist at all, their focus is usually on specialist (tertiary) care. This is clinically and economically inappropriate: most headache disorders can effectively and more efficiently (and at lower cost) be treated in educationally supported primary care. At the same time, compartmentalizing divisions between primary, secondary and tertiary care in many health-care systems create multiple inefficiencies, confronting patients attempting to navigate these levels (the “patient journey”) with perplexing obstacles. High demand for headache care, estimated here in a needs-assessment exercise, is the biggest of the challenges to reform. It is also the principal reason why reform is necessary. The structured headache services model presented here by experts from all world regions on behalf of the Global Campaign against Headache is the suggested health-care solution to headache. It develops and refines previous proposals, responding to the challenge of high demand by basing headache services in primary care, with two supporting arguments. First, only primary care can deliver headache services equitably to the large numbers of people needing it. Second, with educational supports, they can do so effectively to most of these people. The model calls for vertical integration between care levels (primary, secondary and tertiary), and protection of the more advanced levels for the minority of patients who need them. At the same time, it is amenable to horizontal integration with other care services. It is adaptable according to the broader national or regional health services in which headache services should be embedded. It is, according to evidence and argument presented, an efficient and cost-effective model, but these are claims to be tested in formal economic analyses