1,008 research outputs found

    Nuclear spin coherence in a quantum wire

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    We have observed millisecond-long coherent evolution of nuclear spins in a quantum wire at 1.2 K. Local, all-electrical manipulation of nuclear spins is achieved by dynamic nuclear polarization in the breakdown regime of the Integer Quantum Hall Effect combined with pulsed Nuclear Magnetic Resonance. The excitation thresholds for the breakdown are significantly smaller than what would be expected for our sample and the direction of the nuclear polarization can be controlled by the voltage bias. As a four-level spin system, the device is equivalent to two qubits.Comment: 5 pages, 5 figure

    Spontaneous Coronary Artery Dissection as Presenting Feature of Vascular Ehlers-Danlos Syndrome

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    A spontaneous coronary artery dissection as the sole presenting feature of vascular Ehlers-Danlos syndrome is an uncommon finding. We present a 33-year-old woman with sudden onset chest pain caused by a spontaneous coronary artery dissection. Genetic testing revealed vascular Ehlers-Danlos syndrome as the underlying cause. Specifically, we show the value of genetic testing, which in some patients may be the only way of establishing a diagnosis

    A multi-parent recombinant inbred line population of C. elegans allows identification of novel QTLs for complex life history traits

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    Background The nematode Caenorhabditis elegans has been extensively used to explore the relationships between complex traits, genotypes, and environments. Complex traits can vary across different genotypes of a species, and the genetic regulators of trait variation can be mapped on the genome using quantitative trait locus (QTL) analysis of recombinant inbred lines (RILs) derived from genetically and phenotypically divergent parents. Most RILs have been derived from crossing two parents from globally distant locations. However, the genetic diversity between local C. elegans populations can be as diverse as between global populations and could thus provide means of identifying genetic variation associated with complex traits relevant on a broader scale. Results To investigate the effect of local genetic variation on heritable traits, we developed a new RIL population derived from 4 parental wild isolates collected from 2 closely located sites in France: Orsay and Santeuil. We crossed these 4 genetically diverse parental isolates to generate a population of 200 multi-parental RILs and used RNA-seq to obtain sequence polymorphisms identifying almost 9000 SNPs variable between the 4 genotypes with an average spacing of 11 kb, doubling the mapping resolution relative to currently available RIL panels for many loci. The SNPs were used to construct a genetic map to facilitate QTL analysis. We measured life history traits such as lifespan, stress resistance, developmental speed, and population growth in different environments, and found substantial variation for most traits. We detected multiple QTLs for most traits, including novel QTLs not found in previous QTL analysis, including those for lifespan and pathogen responses. This shows that recombining genetic variation across C. elegans populations that are in geographical close proximity provides ample variation for QTL mapping. Conclusion Taken together, we show that using more parents than the classical two parental genotypes to construct a RIL population facilitates the detection of QTLs and that the use of wild isolates facilitates the detection of QTLs. The use of multi-parent RIL populations can further enhance our understanding of local adaptation and life history trade-offs

    Imipenem as mono therapy in the treatment of intensive care patients with severe infections

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    In an open study, 24 intensive care patients were treated with imipenem/cilastatin as monotherapy for serious bacterial infections. Twenty-one patients were treated for bronchopulmonary infection, two patients for septicaemia, and one patient for an empyema. Initially all strains were susceptible to imipenem. Gram-negative bacilli accounted for 80% of these isolates. The most frequently isolated species were Proteus mirabilis, Escherichia coli and Pseudomonas aeruginosa. All 24 patients were considered clinically cured. Sixteen of these patients (67%) were both clinically and microbiologically cured. In eight of the 24 patients (33%), the strains isolated initially persisted. In eight of the 24 patients (33%), colonization of the respiratory tract developed. Two of the five Ps. aeruginosa isolates developed resistance during therapy but in none of these patients was therapy considered to have failed. In 12 patients (50%), transient elevations in hepatic function tests were observed and these were probably drugrelated. The present study supports the view that imipenem/cilastatin may be useful as monotherapy in the treatment of severe infections in intensive care patients

    Simplified Multistep Outflow Method to Estimate Unsaturated Hydraulic Functions for Coarse-Textured Soils

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    Although the multistep outfl ow (MSO) method is well suited for the estimation of soil hydraulic properties by inverse solution techniques, this method has not been widely adopted because it requires advanced instrumentation and is time consuming. Th e objective of this study was to develop a modifi ed version of the multistep outfl ow technique that largely simplifi es laboratory procedures and reduces costs and time. Th e numerical inversion procedures require applying user-friendly HYDRUS soft ware to estimate fi tting parameters for soil water retention and unsaturated hydraulic conductivity curves. Whereas values of saturated water content and saturated hydraulic conductivity must be measured independently, the remaining functional parameters are estimated using an inverse solution of a transient drainage experiment using multiple suction steps and a hanging water column, with drainage outfl ows measured during drainage. A comparison test showed that the simplifi ed experiment without tensiometric measurements provided suffi cient information in the parameter identifi cation compared with a traditional pressure outfl ow experiment with tensiometric measurements for an Oso Flaco sand and a loamy sand fi eld soil in the suction range of 0 to 17 kPa

    Analytic expressions and approximations for the onaxis, aberration-free Rayleigh and Debye integral in the case of focusing fields on a circular aperture

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    We present a derivation of the analytic result for on-axis field values of the Rayleigh diffraction integral, a result that was originally presented in a paper b

    Effectiveness and cost-effectiveness of rubber band ligation versus sutured mucopexy versus haemorrhoidectomy in patients with recurrent haemorrhoidal disease (Napoleon trial):Study protocol for a multicentre randomized controlled trial

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    Background: Currently, there is no consensus regarding the best treatment option in recurrent haemorrhoidal disease (HD), due to a lack of solid evidence. The Napoleon trial aims to provide high-level evidence on the comparative effectiveness and cost-effectiveness of repeat rubber band ligation (RBL) versus sutured mucopexy versus haemorrhoidectomy in patients with recurrent HD. Methods: This is a multicentre randomized controlled trial. Patients with recurrent HD grade II and III, >= 18 years of age and who had at least two RBL treatments in the last three years are eligible for inclusion. Exclusion criteria include previous rectal or anal surgery, rectal radiation, pre-existing sphincter injury or otherwise pathologies of the colon and rectum, pregnancy, presence of hypercoagulability disorders, and medically unfit for surgery (ASA > III). Between June 2020 and May 2022, 558 patients will be randomized to receive either: (1) RBL, (2) sutured mucopexy, or (3) haemorrhoidectomy. The primary outcomes are recurrence after 52 weeks and patient-reported symptoms measured by the PROM-HISS. Secondary outcomes are impact on daily life, treatment satisfaction, early and late complication rates, health-related quality of life, costs and cost-effectiveness, and budget impact. Cost-effectiveness will be expressed in societal costs per Quality Adjusted Life Year (QALY) (based on EQ-5D-5L), and healthcare costs per recurrence avoided. Discussion: The best treatment option for recurrent HD remains unknown. The comparison of three generally accepted treatment strategies in a randomized controlled trial will provide high-level evidence on the most (cost) effective treatment
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