5,376 research outputs found

    Impact of OKT3 therapy on cytomegalovirus and herpes simplex virus infections after liver transplantation

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    The purpose of this study was to analyze the impact of OKT3 on the frequency and severity of CMV and herpes simplex virus (HSV) infections in adult liver transplant recipients. OKT3 treatment is associated with a higher risk of disseminated CMV infection, particularly in patients with primary CMV infection. It also increased the frequency of symptomatic HSV infection in HSV-seropositive liver transplant recipients

    Fungal infections after liver transplantation

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    The risk factors for development of invasive fungal infections after liver transplantation were (1) longer duration of treatment with nonprophylactic IV antibiotics, (2) longer cumulative surgical time and a higher number of laparotomies, (3) an increased number of units of RBCs and fresh-frozen plasma, and (4) a series of pretransplant laboratory findings: thrombocytopenia, low T lymphocyte levels, low CD4 helper cell and lower helper/suppressor cell ratios and IgA serum levels. The significance of some of these findings is still unclear. Attention to the risk factors outlined earlier may aid both in preventing and in the early detection of invasive fungal infections after liver transplantation

    Infections with cytomegalovirus and other herpesviruses in 121 liver transplant recipients: Transmission by donated organ and the effect of OKT3 antibodies

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    One hundred twenty-one adult liver transplant recipients were studied for the incidence, risk factors, and morbidity associated with herpesviruses infections after transplantation. The overall incidence of infection was 59% for cytomegalovirus (CMV), 35% for herpes simplex virus (HSV), 25% for Epstein-Barr virus (EBV), and 7% for varicella-zoster virus (VZV). Primary CMV infection occurred in 46% and reactivation CMV infection in 67% of the susceptible recipients. Symptomatic and disseminated CMV diseases were more common when patients developed primary infection (P .10). Although most HSV infections were oral or genital reactivations, three cases of HSV hepatitis occurred - one was primary infection. Symptomatic reactivations of HSV were observed in 53% of HSV-seropositive recipients who received OKT3, versus 31% of seropositive recipients who did not receive OKT3 (P = .05)

    Effect modifications of smoking on risk of mortality associated with influenza

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    BACKGROUND AND AIMS: Influenza is well known to cause heavy disease burden in both temperate and tropical/subtropical regions. Although smoking has been found to increase susceptibility to influenza infection, its role in modifying the mortality risk associated with influenza remains unexplored. This study examined the effect modifications of cigarette smoking on influenza-associated mortality in a cohort of older …postprin

    Phase-slip induced dissipation in an atomic Bose-Hubbard system

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    Phase slips play a primary role in dissipation across a wide spectrum of bosonic systems, from determining the critical velocity of superfluid helium to generating resistance in thin superconducting wires. This subject has also inspired much technological interest, largely motivated by applications involving nanoscale superconducting circuit elements, e.g., standards based on quantum phase-slip junctions. While phase slips caused by thermal fluctuations at high temperatures are well understood, controversy remains over the role of phase slips in small-scale superconductors. In solids, problems such as uncontrolled noise sources and disorder complicate the study and application of phase slips. Here we show that phase slips can lead to dissipation for a clean and well-characterized Bose-Hubbard (BH) system by experimentally studying transport using ultra-cold atoms trapped in an optical lattice. In contrast to previous work, we explore a low velocity regime described by the 3D BH model which is not affected by instabilities, and we measure the effect of temperature on the dissipation strength. We show that the damping rate of atomic motion-the analogue of electrical resistance in a solid-in the confining parabolic potential fits well to a model that includes finite damping at zero temperature. The low-temperature behaviour is consistent with the theory of quantum tunnelling of phase slips, while at higher temperatures a cross-over consistent with the transition to thermal activation of phase slips is evident. Motion-induced features reminiscent of vortices and vortex rings associated with phase slips are also observed in time-of-flight imaging.Comment: published in Nature 453, 76 (2008

    Micro-Electro-Mechanical-Systems (MEMS) and Fluid Flows

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    The micromachining technology that emerged in the late 1980s can provide micron-sized sensors and actuators. These micro transducers are able to be integrated with signal conditioning and processing circuitry to form micro-electro-mechanical-systems (MEMS) that can perform real-time distributed control. This capability opens up a new territory for flow control research. On the other hand, surface effects dominate the fluid flowing through these miniature mechanical devices because of the large surface-to-volume ratio in micron-scale configurations. We need to reexamine the surface forces in the momentum equation. Owing to their smallness, gas flows experience large Knudsen numbers, and therefore boundary conditions need to be modified. Besides being an enabling technology, MEMS also provide many challenges for fundamental flow-science research

    Seatbelt use and risk of major injuries sustained by vehicle occupants during motor-vehicle crashes: A systematic review and meta-analysis of cohort studies

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    BackgroundIn 2004, a World Health Report on road safety called for enforcement of measures such as seatbelt use, effective at minimizing morbidity and mortality caused by road traffic accidents. However, injuries caused by seatbelt use have also been described. Over a decade after publication of the World Health Report on road safety, this study sought to investigate the relationship between seatbelt use and major injuries in belted compared to unbelted passengers.MethodsCohort studies published in English language from 2005 to 2018 were retrieved from seven databases. Critical appraisal of studies was carried out using the Scottish Intercollegiate Guidelines Network (SIGN) checklist. Pooled risk of major injuries was assessed using the random effects meta-analytic model. Heterogeneity was quantified using I-squared and Tau-squared statistics. Funnel plots and Egger's test were used to investigate publication bias. This review is registered in PROSPERO (CRD42015020309).ResultsEleven studies, all carried out in developed countries were included. Overall, the risk of any major injury was significantly lower in belted passengers compared to unbelted passengers (RR 0.47; 95%CI, 0.29 to 0.80; I-2=99.7; P=0.000). When analysed by crash types, belt use significantly reduced the risk of any injury (RR 0.35; 95%CI, 0.24 to 0.52). Seatbelt use reduces the risk of facial injuries (RR=0.56, 95% CI=0.37 to 0.84), abdominal injuries (RR=0.87; 95% CI=0.78 to 0.98) and, spinal injuries (RR=0.56, 95% CI=0.37 to 0.84). However, we found no statistically significant difference in risk of head injuries (RR=0.49; 95% CI=0.22 to 1.08), neck injuries (RR=0.69: 95%CI 0.07 to 6.44), thoracic injuries (RR 0.96, 95%CI, 0.74 to 1.24), upper limb injuries (RR=1.05, 95%CI 0.83 to 1.34) and lower limb injuries (RR=0.77, 95%CI 0.58 to 1.04) between belted and non-belted passengers.ConclusionIn sum, the risk of most major road traffic injuries is lower in seatbelt users. Findings were inconclusive regarding seatbelt use and susceptibility to thoracic, head and neck injuries during road traffic accidents. Awareness should be raised about the dangers of inadequate seatbelt use. Future research should aim to assess the effects of seatbelt use on major injuries by crash type

    Smc5/6 coordinates formation and resolution of joint molecules with chromosome morphology to ensure meiotic divisions

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    During meiosis, Structural Maintenance of Chromosome (SMC) complexes underpin two fundamental features of meiosis: homologous recombination and chromosome segregation. While meiotic functions of the cohesin and condensin complexes have been delineated, the role of the third SMC complex, Smc5/6, remains enigmatic. Here we identify specific, essential meiotic functions for the Smc5/6 complex in homologous recombination and the regulation of cohesin. We show that Smc5/6 is enriched at centromeres and cohesin-association sites where it regulates sister-chromatid cohesion and the timely removal of cohesin from chromosomal arms, respectively. Smc5/6 also localizes to recombination hotspots, where it promotes normal formation and resolution of a subset of joint-molecule intermediates. In this regard, Smc5/6 functions independently of the major crossover pathway defined by the MutLγ complex. Furthermore, we show that Smc5/6 is required for stable chromosomal localization of the XPF-family endonuclease, Mus81-Mms4Eme1. Our data suggest that the Smc5/6 complex is required for specific recombination and chromosomal processes throughout meiosis and that in its absence, attempts at cell division with unresolved joint molecules and residual cohesin lead to severe recombination-induced meiotic catastroph

    Gravitational waves from single neutron stars: an advanced detector era survey

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    With the doors beginning to swing open on the new gravitational wave astronomy, this review provides an up-to-date survey of the most important physical mechanisms that could lead to emission of potentially detectable gravitational radiation from isolated and accreting neutron stars. In particular we discuss the gravitational wave-driven instability and asteroseismology formalism of the f- and r-modes, the different ways that a neutron star could form and sustain a non-axisymmetric quadrupolar "mountain" deformation, the excitation of oscillations during magnetar flares and the possible gravitational wave signature of pulsar glitches. We focus on progress made in the recent years in each topic, make a fresh assessment of the gravitational wave detectability of each mechanism and, finally, highlight key problems and desiderata for future work.Comment: 39 pages, 12 figures, 2 tables. Chapter of the book "Physics and Astrophysics of Neutron Stars", NewCompStar COST Action 1304. Minor corrections to match published versio
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