1,345 research outputs found

    DEVELOPMENT OF A DYNAMIC BALLOON VOLUME SENSOR SYSTEM FOR USE IN PULSATING BALLOON CATHETERS WITH CHANGING HELIUM CONCENTRATIONS

    Get PDF
    A dynamic balloon volume sensor system (DBVSS) was designed for use with the intra-aortic balloon pump (IABP), a therapeutic device to assist heart recovery after cardiac dysfunction or cardiac trauma, and the Pittsburgh respiratory support catheter (RSC), an internally deployed gas exchange device which augments lung function. The DBVSS was designed to detect the degree of inflation of the balloons incorporated into each device as they pulse within a patient. Both devices require full inflation for optimal performance, and both will under-inflate during normal operation. The sensor system requirements were to measure volumes within 10% of the actual across the range of expected pulsation frequencies as well as in changing concentrations of helium.The DBVSS employed a hot wire anemometer to detect the flow entering the balloon, combined with a computer algorithm to integrate the flow to find volume. The system compensated for the flow reading changes resulting from changing helium concentration by measuring gas properties during zero gas flow between pulsations, and used this data to correct the flow profile at each helium concentration. The volume from the DBVSS was compared to the volume standard as measured by water displacement in a plethysmograph.The system was able to accurately measure delivered balloon volume under changing gas composition as well as detected volume loss from the balloon across helium concentrations. The DBVSS measured the volume within 10% across these tests, as well as under compression of the balloon, high resistance in the driveline and across frequencies up to 480 beats per minute. The DBVSS was proved to be within the design requirements for helium concentration and inflation methods for both the devices considered

    Endogenous signaling through α7-containing nicotinic receptors promotes maturation and integration of adult-born neurons in the hippocampus

    Get PDF
    Neurogenesis in the dentate gyrus occurs throughout adult mammalian life and is essential for proper hippocampal function. Early in their development, adult-born neurons express homomeric α7-containing nicotinic acetylcholine receptors (α7-nAChRs) and receive direct cholinergic innervation. We show here that functional α7-nAChRs are necessary for normal survival, maturation, and integration of adult-born neurons in the dentate gyrus. Stereotaxic retroviral injection into the dentate gyrus of wild-type and α7-knock-out (α7KO) male and female mice was used to label and birthdate adult-born neurons for morphological and electrophysiological measures; BrdU (5-bromo-2-deoxyuridine) injections were used to quantify cell survival. In α7KO mice, we find that adult-born neurons develop with truncated, less complex dendritic arbors and display GABAergic postsynaptic currents with immature kinetics. The neurons also have a prolonged period of GABAergic depolarization characteristic of an immature state. In this condition, they receive fewer spontaneous synaptic currents and are more prone to die during the critical period when adult-born neurons are normally integrated into behaviorally relevant networks. Even those adult-born neurons that survive the critical period retain long-term dendritic abnormalities in α7KO mice. Interestingly, local infection with retroviral constructs to knockdown α7-mRNA mimics the α7KO phenotype, demonstrating that the relevant α7-nAChR signaling is cell autonomous. The results indicate a profound role for α7-nAChRs in adult neurogenesis and predict that α7-nAChR loss will cause progressive impairment in hippocampal circuitry and function over time as fewer neurons are added to the dentate gyrus and those that are added integrate less well.This work was supported by National Institutes of Health Grants NS012601 and N0S35469, and the Tobacco-Related Disease Research Program (16RT-0167). N.R.C. is a Tobacco-Related Disease Research Program predoctoral fellow. C.C.F. is a Fundação Calouste Gulbenkian Graduate Fellow. A.W.F. is a National Research Service Award predoctoral fellow. We thank Gouping Feng (Duke University, Durham, NC) for the GFP-reporter mouse line and Xiao-Yun Wang for expert technical assistance

    EBI3 regulates the NK cell response to mouse cytomegalovirus infection

    Get PDF
    Natural killer (NK) cells are key mediators in the control of cytomegalovirus infection. Here, we show that Epstein-Barr virus-induced 3 (EBI3) is expressed by human NK cells after NKG2D or IL-12 plus IL-18 stimulation and by mouse NK cells during mouse cytomegalovirus (MCMV) infection. The induction of EBI3 protein expression in mouse NK cells is a late activation event. Thus, early activation events of NK cells, such as IFNγ production and CD69 expression, were not affected in EBI3-deficient (Ebi3-/- ) C57BL/6 (B6) mice during MCMV infection. Furthermore, comparable levels of early viral replication in spleen and liver were observed in MCMV-infected Ebi3-/- and wild-type (WT) B6 mice. Interestingly, the viral load in salivary glands and oral lavage was strongly decreased in the MCMV-infected Ebi3-/- B6 mice, suggesting that EBI3 plays a role in the establishment of MCMV latency. We detected a decrease in the sustained IL-10 production by NK cells and lower serum levels of IL-10 in the MCMV-infected Ebi3-/- B6 mice. Furthermore, we observed an increase in dendritic cell maturation markers and an increase in activated CD8+ T cells. Thus, EBI3 dampens the immune response against MCMV infection, resulting in prolonged viral persistence

    Boarfish Acoustic Survey Cruise Report 10 July – 31 July, 2013

    Get PDF
    Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report.From the early 1970s the abundance of boarfish (Capros aper) was seen to increase exponentially and distribution spread increasingly northwards along the western seaboard and Bay of Biscay (Blanchard and Vandermeirsch, 2005). This survey represents the third dedicated research survey for boarfish in the time series. The commercial fishing vessel MFV Felucca (as in 2011), an active participant in the fishery, was equipped with a calibrated scientific echosounder (Simrad EK 60) and transducer within a towed body. Data from this survey, in addition to the extensive biological research carried out on this species, forms part of a larger program aimed at increasing the knowledge of this species and its abundance outside of the commercial fishery. Data from this survey will be presented for inclusion into the ICES Planning Group meeting for International Pelagic Surveys in January 2014 (WGIPS) and for the ICES assessment Working Group for Widely Distributed Stocks (WGWIDE) meeting in August 2013

    Preparation and Crystal Structure of a Platinum(II) Complex of [CH2N(CH2COOH)CH2CONH2]2, the Hydrolysis Product of an Anti-Tumour Bis(3,5-Dioxopiperazin-1-YL)Alkane

    Get PDF
    The synthesis and crystal and molecular structures of the platinum(II) complex Pt(HL)Cl where H2L is the diacid diamide –[CH2N(CH2COOH)CH2CONH2]2, a hydrolytic metabolite of an antitumour active bis(3,5-dioxopiperazin-1-yl)alkane are reported. The complex is square planar and contains HL– as a tridentate 2N (amino), O (carboxylate) donor. The metal to ligand bond distances are Pt-Cl 2.287(1) Å, Pt-O 2.002 (1) Å, Pt-Ntrans Cl 2.014(1) Å and Pt-Ntrans O 2.073 Å. There is extensive hydrogen bonding, each molecule of Pt(HL)Cl being intermolecularly hydrogen bonded to ten others giving a 3-dimensional network. There is also one intramolecular H-bond

    A Qualitative Study Exploring How the Aims, Language and Actions of Yoga for Pregnancy Teachers May Impact Upon Women's Self-efficacy for Labour and Birth

    Get PDF
    As women's anxiety and the rate of medical intervention in labour and birth continue to increase, it is important to identify how antenatal education can increase women's confidence and their ability to manage the intense sensations of labour. To report a grounded theory study of how the aims, language and actions of yoga for pregnancy teachers may impact upon women's self-efficacy for labour and birth. Yoga for pregnancy classes in three locations were filmed. Semi-structured interviews were undertaken with the teachers to explore what they were trying to achieve in their classes, and how. Interviews and classes were transcribed and analysed using grounded theory. There was considerable consistency in the teachers’ aims, the language they used in classes and in their thinking about class structure. Four main themes emerged: creating a sisterhood, modelling labour, building confidence and enhancing learning. Teachers see yoga for pregnancy as a multi-faceted, non-prescriptive intervention that enhances women's physical, emotional and social readiness for labour and birth, and supports women to make their own decisions across the transition to parenthood. Women's self-efficacy for labour is complex and multi-factorial. This study offers insights into the factors which may be involved in increasing it. These include not only traditional elements of yoga such as postures, breathing and meditation, but also the creation of safe, women-only groups where anxieties, experiences and stories can be shared, and pain-coping techniques for labour learned and practised

    Trematodes of the Great Barrier Reef, Australia: emerging patterns of diversity and richness in coral reef fishes

    Get PDF
    The Great Barrier Reef holds the richest array of marine life found anywhere in Australia, including a diverse and fascinating parasite fauna. Members of one group, the trematodes, occur as sexually mature adult worms in almost all Great Barrier Reef bony fish species. Although the first reports of these parasites were made 100 years ago, the fauna has been studied systematically for only the last 25 years. When the fauna was last reviewed in 1994 there were 94 species known from the Great Barrier Reef and it was predicted that there might be 2,270 in total. There are now 326 species reported for the region, suggesting that we are in a much improved position to make an accurate prediction of true trematode richness. Here we review the current state of knowledge of the fauna and the ways in which our understanding of this fascinating group is changing. Our best estimate of the true richness is now a range, 1,100–1,800 species. However there remains considerable scope for even these figures to be incorrect given that fewer than one-third of the fish species of the region have been examined for trematodes. Our goal is a comprehensive characterisation of this fauna, and we outline what work needs to be done to achieve this and discuss whether this goal is practically achievable or philosophically justifiable
    • …
    corecore