448 research outputs found

    The synthesis of monomers with pendent ethynyl group for modified high performance thermoplastics

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    The objectives of this project were to develop synthetic schemes for the following classes of modified monomers: (1) difunctional triarylethanes with pendent acetylenic groups; and (2) tertiary aspartimides with terminal acetylene groups at the two ends. Our efforts have resulted in the successful development of high yield schemes for the syntheses of several diamino and bisphenolic analogs of difunctional triarylethanes with pendent ethynyl group. A scheme for one new tertiary aspartimide was also established. Multi-gram samples of all prepared new monomers were provided to our technical contact at NASA-LaRC and preliminary polymerization studies were encouraging. Details of the accomplished work within the last four years are described

    The synthesis of monomers with pendent ethynyl groups for modified high performance thermoplastics

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    Synthetic schemes were developed and optimized for twelve new monomers possessing unique structural features and one aspartimide. Two synthetic pathways were compared for preparation of the triarylethane monomers with pendent ethynyl groups. The results show that one of these pathways can be generally applied. The alternative pathway was applicable to the preparation of only one of the twelve compounds, the problem being secondary reactions of the initially formed desired product

    Remuneration of primary dental care in England: a qualitative framework analysis of perspectives of a new service delivery model incorporating incentives for improved access, quality and health outcomes

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    Objective: This study aimed to describe stakeholder perspectives of a new service delivery model in primary care dentistry incorporating incentives for access, quality and health outcomes. Design: Data were collected through observations, interviews and focus groups. Setting: This was conducted under six UK primary dental care practices, three working under the incentive-driven contract and three working under the traditional activity-based contract. Participants: Observations were made of 30 dental appointments. Eighteen lay people, 15 dental team staff and a member of a commissioning team took part in the interviews and focus groups. Results: Using a qualitative framework analysis informed by Andersen’s model of access, we found oral health assessments influenced patients’ perceptions of need, which led to changes in preventive behaviour. Dentists responded to the contract, with greater emphasis on prevention, use of the disease risk ratings in treatment planning, adherence to the pathways and the utilisation of skill-mix. Participants identified increases in the capacity of practices to deliver more care as a result. These changes were seen to improve evaluated and perceived health and patient satisfaction. These outcomes fed back to shape people’s predispositions to visit the dentist. Conclusion: The incentive-driven contract was perceived to increase access to dental care, determine dentists’ and patients’ perceptions of need, their behaviours, health outcomes and patient satisfaction. Dentists face challenges in refocusing care, perceptions of preventive dentistry, deployment of skill mix and use of the risk assessments and care pathways. Dentists may need support in these areas and to recognise the differences between caring for individual patients and the patient-base of a practice

    Assessment of Noise and Associated Health Impacts at Selected Secondary Schools in Ibadan, Nigeria

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    Background. Most schools in Ibadan, Nigeria, are located near major roads (mobile line sources). We conducted an initial assessment of noise levels and adverse noise-related health and learning effects. Methods. For this descriptive, cross-sectional study, four schools were selected randomly from eight participating in overall project. We administered 200 questionnaires, 50 per school, assessing health and learning-related outcomes. Noise levels (A-weighted decibels, dBA) were measured with calibrated sound level meters. Traffic density was assessed for school with the highest measured dBA. Observational checklists assessed noise control parameters and building physical attributes. Results. Short-term, cross-sectional school-day noise levels ranged 68.3–84.7 dBA. Over 60% of respondents reported that vehicular traffic was major source of noise, and over 70% complained being disturbed by noise. Three schools reported tiredness, and one school lack of concentration, as the most prevalent noise-related health problems. Conclusion. Secondary school occupants in Ibadan, Nigeria were potentially affected by exposure to noise from mobile line sources

    Epidemiology of lumbar disc herniations in adults with low back pain in Enugu, Nigeria

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    Background: Lumbar intervertebral disc herniation is used to describe a spectrum of anatomical abnormalities involving disc extension beyond the interspace. It follows a tear in the annulus fibrosus of the intervertebral disc. It is one of the most common causes of low back pain among adults. The study aims to assess the epidemiological pattern of lumbar disc herniations among adults with low back pain in Enugu urban.Methods: The study was a prospective study at National Orthopedic Hospital Enugu and Annunciation Specialist Hospital Enugu. Following ethical approval and written informed consent, patients who met the inclusion criteria were consecutively recruited. The MRI scans of the participants were viewed using DICOM® (Digital Imaging and Communications in Medicine) software on laptop computer. The data included the patients’ demographics, functional disability index for back pain, weight, height, the anatomical level(s) and site(s) of the herniated disc among other parameters.Results: A total of 81 subjects who met the inclusion criteria were included and analyzed using SPSS version 20.0. The mean age of the subjects is 52.99±13.13 years. The most common affected age group is 51-60 years (27.2%). Majority of the subjects (68; 84%) had multiple level herniations which usually includes L4 level(74; 91.4%).Conclusions: That multilevel lumbar disc herniation is far more common than single level herniation with a prevalence of 84% among adults with low back pain in Enugu urban. That, there is statistically significant association of lumbar disc herniation and increasing age

    An exploratory study looking at the relationship marketing techniques used in the music festival industry

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    There are current issues and trends in the music festival market, which may affect the success of an event, and market saturation is at the forefront of these issues. Previous literature, maintaining the need for a marketing approach to festivals, identifi es the need for maintaining strong stakeholder relationships in order to succeed in a business environment; attention has been focused to the theory of relationship marketing (RM) because of the recognition that this practice is complementary to the marketing of festivals. The very nature of the music festival as an annual, usually, 4-day event means that effective marketing is needed to keep connections with the consumer throughout the year. This article focuses on the RM techniques utilised within the music festival industry from the viewpoint of the festival organiser in an attempt to establish how festival organisations value and monitor organisational relationships. This article explores the extent to which these relationships are valued and managed; furthermore, the variations between these intricate relationships are considered by focusing on those held with the organisation ’ s consumers and sponsors, the results of which have provided the ability to establish the importance and relevance of RM to the industry and further identify the marketing communication methods employed to establish and maintain such relationships. In-depth, convergent interviews have been conducted with a segment of music festival organisers from a range of events. The results have been integrated with the study of current literature to best exemplify these issues. It has been established that RM has a strong role in today ’ s commercial and independent music festival industry; technological advances are enabling the organiser to support online relationships further and increase consumer loyalty. There is a need to expand the research further because of the complexity of organisational relationships and the varying categories of festivals

    Asymmetric Synthesis and Biological Screening of Quinoxaline-Containing Synthetic Lipoxin A₄ Mimetics (QNX-sLXms)

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    Failure to resolve inflammation underlies many prevalent pathologies. Recent insights have identified lipid mediators, typified by lipoxins (LXs), as drivers of inflammation resolution, suggesting potential therapeutic benefit. We report the asymmetric preparation of novel quinoxaline-containing synthetic-LXA4-mimetics (QNX-sLXms). Eight novel compounds were screened for their impact on inflammatory responses. Structure–activity relationship (SAR) studies showed that (R)-6 (also referred to as AT-02-CT) was the most efficacious and potent anti-inflammatory compound of those tested. (R)-6 significantly attenuated lipopolysaccharide (LPS)- and tumor-necrosis-factor-α (TNF-α)-induced NF-κB activity in monocytes and vascular smooth muscle cells. The molecular target of (R)-6 was investigated. (R)-6 activated the endogenous LX receptor formyl peptide receptor 2 (ALX/FPR2). The anti-inflammatory properties of (R)-6 were further investigated in vivo in murine models of acute inflammation. Consistent with in vitro observations, (R)-6 attenuated inflammatory responses. These results support the therapeutic potential of the lead QNX-sLXm (R)-6 in the context of novel inflammatory regulators

    Asymmetric Synthesis and Biological Screening of Quinoxaline-Containing Synthetic Lipoxin A4 Mimetics (QNX-sLXms)

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    Failure to resolve inflammation underlies many prevalent pathologies. Recent insights have identified lipid mediators, typified by lipoxins (LXs), as drivers of inflammation resolution, suggesting potential therapeutic benefit. We report the asymmetric preparation of novel quinoxaline-containing syntheticLXA4-mimetics (QNX-sLXms). Eight novel compounds were screened for their impact on inflammatory responses. Structure− activity relationship (SAR) studies showed that (R)-6 (also referred to as AT-02-CT) was the most efficacious and potent anti-inflammatory compound of those tested. (R)-6 significantly attenuated lipopolysaccharide (LPS)- and tumor-necrosis-factor-α (TNF-α)-induced NF-κB activity in monocytes and vascular smooth muscle cells. The molecular target of (R)-6 was investigated. (R)-6 activated the endogenous LX receptor formyl peptide receptor 2 (ALX/FPR2). The anti-inflammatory properties of (R)-6 were further investigated in vivo in murine models of acute inflammation. Consistent with in vitro observations, (R)-6 attenuated inflammatory responses. These results support the therapeutic potential of the lead QNX-sLXm (R)-6 in the context of novel inflammatory regulators

    Chemical speciation and health risks of airborne heavy metals around an industrial community in Nigeria.

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    Quantification of PM2.5 (particulate matter <2.5 μm) bound heavy metals and their potential health risks were carried out around a cement manufacturing company in Ewekoro, Nigeria. The PM2.5 samples were collected using Environtech gravimetric sampler. A four-staged sequential extraction procedure was used to fractionate PM2.5 bound chromium (Cr), lead (Pb), aluminum (Al), copper (Cu), and silver (Ag), and further analyzed using inductively coupled plasma mass spectrometry. Chemical speciation results reveal bioavailable levels of Pb (4.05 μg/m3), Cr (10.75 μg/m3), Al (16.47 μg/m3), Cu (4.38E-01 μg/m3), and Ag (1.22E-02 μg/m3) in the airborne particulates. Pb and Cr levels exceeded the World Health Organization allowable limit of 0.5 and 2.5E-05 μg/m3, respectively. The labile phases showed strong indication of the presence of Cr and Cu metal. Excess cancer risks exposure for adults, outdoor workers and children were higher than the acceptable risk target level of 1E-06. Noncarcinogenic health risk estimated using hazard quotients (HQs) and hazard indices (HIs) showed ingestion route within the safe level of HI <1 implying no adverse effect while inhalation route exceeded the safe level for all receptors. Enforcement of pollution control by authorized agencies, and screening of greenbelts as sinks for air pollutants is strongly recommended
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