36 research outputs found

    Simultaneous control of spectroscopic and electrochemical properties in functionalised electrochemiluminescent tris(2,2\u27-bipyridine)ruthenium(II) complexes

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    Using a combination of electrochemical, spectroscopic and computational techniques, we have explored the fundamental properties of a series of ruthenium diimine complexes designed for coupling with other molecules or surfaces for electrochemiluminescence (ECL) sensing applications. With appropriate choice of ligand functionality, it is possible to manipulate emission wavelengths while keeping the redox ability of the complex relatively constant. DFT calculations show that in the case of electron withdrawing substituents such as ester or amide, the excited state is located on the substituted bipyridine ligand whereas in the case of alkyl functionality it is localised on a bipyridine. The factors that dictate annihilation ECL efficiency are interrelated. For example, the same factors that determine ΔG for the annihilation reaction (i.e. the relative energies of the HOMO and LUMO) have a corresponding effect on the energy of the excited state product. As a result, most of the complexes populate the excited state with an efficiency (Φex) of close to 80% despite the relatively wide range of emission maxima. The quantum yield of emission (Φp) and the possibility of competing side reactions are found to be the main determinants of ECL intensity

    Human cloning in film: horror, ambivalence, hope

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    Fictional filmic representations of human cloning have shifted in relation to the 1997 announcement of the birth of Dolly the cloned sheep, and since therapeutic human cloning became a scientific practice in the early twentieth century. The operation and detail of these shifts can be seen through an analysis of the films The Island (2005) and Aeon Flux (2005). These films provide a site for the examination of how these changes in human cloning from fiction to practice, and from horror to hope, have been represented and imagined, and how these distinctions have operated visually in fiction, and in relation to genre

    Reliability of race assessment based on the race of the ascendants: a cross-sectional study

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    BACKGROUND: Race is commonly described in epidemiological surveys based on phenotypic characteristics. Training of interviewers to identify race is time-consuming and self identification of race might be difficult to interpret. The aim of this study was to determine the agreement between race definition based on the number of ascendants with black skin colour, with the self-assessment and observer's assessment of the skin colour. METHODS: In a cross-sectional study of 50 women aged 14 years or older, from an outpatient clinic of an University affiliated hospital, race was assessed through observation and the self-assignment of the colour of skin and by the number of black ascendants including parents and grandparents. Reliability was measured through Kappa coefficient. RESULTS: Agreement beyond chance between self-assigned and observed skin colour was excellent for white (0.75 95% CI 0.72–0.78) and black women (0.89 95% CI 0.71–0.79), but only good for participants with mixed colour (0.61 95% CI 0.58–0.64), resulting in a global kappa of 0.75 (95% CI 0.71–0.79). However, only a good agreement for mixed women was obtained. The presence of 3 or more black ascendants was highly associated with observed and self-assessed black skin colour. Most women self-assigned or observed as white had no black ascendants. CONCLUSIONS: The assessment of race based on the race of ascendants showed reasonable agreement with the ascertainment done by trained interviewers and with the self-report of race. This method may be considered for evaluation of race in epidemiological surveys, since it is less time-consuming than the evaluation by interviewers

    'A tragedy as old as history':Medical responses to infertility and artificial insemination by donor in 1950s Britain

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    This chapter will explore how the infertile patient was characterized, perceived, and treated by the medical profession in 1950s England and Scotland. Such was the concern that this subject engendered in postwar Britain that a Departmental Committee was appointed in 1958 (known as the Feversham Committee) to investigate infertility and its treatment through artificial insemination. The written and oral evidence submitted by medical witnesses to that Committee offers rich insights into medical thinking and practice, and into the complex sociomedical politics and ethical anxieties which surrounded the topic. The testimony of legal and religious witnesses will also be explored to a more limited extent in order to offer some context to medical understandings and treatments of infertility. It will be considered how women’s bodies, personalities, and even agency in proactively seeking motherhood through artificial insemination were heavily pathologized in medical and religious discourses, but also how the men involved – husbands, sperm donors and even doctors – did not escape this tendency to pathologize

    Screening for breast cancer: candidacy and compliance

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    This paper is concerned with understanding why some women accept their invitation for free screening mammography and others do not. Free screening mammography is offered to women aged 50-64 in Britain. Uptake of invitations is about twice as high in leafy suburbs than in inner-city areas. Low uptake in inner-city areas has been attributed to 'problems' of black and minority ethnic women. The research reported here was carried out in Hackney, an inner city London borough with an ethnically diverse and socially deprived population. Hackney also has the lowest uptake of screening mammography in the country. Twenty focus groups were held. Participants included white, black and minority ethnic women. Eight focus groups were conducted in English; 12 in other languages. Some methodological issues raised by undertaking qualitative research in several languages are considered. The research demonstrates how the inclusion of white women in research which operationalises ethnicity minimizes the risk of developing an analysis focusing on 'problems' of black and minority ethnic women and encourages the development of general themes which may apply to all women. The analysis focuses on candidacy, that is, women's assessment of risk of their disease, and compliance, that is, the explanations respondents volunteered for accepting or refusing an invitation to attend for mammography. Candidacy and ethnicity emerge as similar constructs, manipulated by women to make claims about their risk of breast cancer. Other, non-medical reasons were given for compliance which serve as a warning about assuming that, when women accept their invitation, they do so for same the reasons the architects of the National Health Service Breast Screening Programme had in mind.Breast cancer Screening Ethnicity Candidacy Compliance

    What British women say matters to them about donating an aborted fetus to stem cell research: A focus group study

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    This is the first investigation into what matters to British women when they think about donating an aborted fetus to research, and how stem cell research and therapies might influence their views. Tissue derived from the aborted fetus is considered "the right tool for the job" in some stem cell laboratories. Research using tissue derived from aborted fetuses is permitted in Britain, while deliberate abortion to provide fetal tissue for research is illegal. Investigators are advised to seek women's agreement to donate the fetus after they have signed the consent form for the abortion, and stem cell researchers seek fetuses aborted under the 'social' grounds of the Abortion Act 1967. This research was based on focus groups with women who had both had a termination and had not had a termination. It found that initial enthusiasm for the donation of the aborted fetus for medical research, which was understood as a good thing, diminished as participants gained information and thought more carefully about the implications of such a decision. Lack of knowledge about how aborted fetuses are treated as scientific objects in the stem cell laboratory provoked concerns about mishandling, and invoked in some participants what we have called the duty of care which women feel towards babies and children. The duty of care might apply to other research using aborted fetuses. But what makes stem cell research more troubling is its association with renewal, regeneration, and immortality which participants understood as somehow reinstating and even developing the fetus' physical existence and social biography, the very thing abortion is meant to eliminate. By the end of the focus groups, participants had co-produced a tendency to refuse to donate aborted fetuses.UK Stem cell research Aborted fetuses Fetal tissue Tissue donation Abortion
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