726 research outputs found

    Hormonal modifications in patients admitted to an internal intensive care unit for acute hypoxaemic respiratory failure

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    AbstractTo clarify which endocrine modifications can be observed in acute hypoxaemic respiratory failure, 15 severely ill male patients [PAT; median age: 61 (range: 48 years); median height: 173 (range: 12) cm; median mass: 73 (range 31) kg] were investigated immediately upon admission to an intensive care unit (ICU) for this clinical disorder. Before starting treatment, the blood gases were measured and a number of selected hormones with special relevance for an ICU setting were determined. These are known to be modified by acute hypoxaemia in healthy subjects and to possess glucoregulatory properties, or an influence upon cardiocirculation or the vascular volume regulation: insulin, cortisol, adrenaline, noradrenaline, atrial natriuretic peptide, renin, aldosterone, angiotensin converting enzyme, and endothelin-I (ET). To elucidate whether potential endocrine changes resulted from acute hypoxaemia alone, the underlying disease, or unspecific influences connected with the ICU setting, all measurements were compared to those of a completely healthy reference group (REF) with comparable acute experimental hypoxaemia. The latter state was achieved by having the REF breathe a gas mixture with the oxygen content reduced to 14% (H).In the REF, neither the medians nor the distribution of endocrinologic measurements were modified significantly by acute hypoxaemia. In the PAT, the medians were increased considerably, yet with a slight diminution of ET. The distribution of individual values was considerably broader than in the REF with H.In conclusion, considerable increases in the means of the above hormones, with the exception of ET, can be registered in severely ill patients admitted to ICUs with acute hypoxaemic failure. However, such modifications cannot be considered attributable exclusively to acute arterial hypoxaemia. The underlying clinical disorders, such as septicaemia or an unspecific endocrine epiphenomenon, including severe and not only hypoxaemic stress, seem to be predominant

    Investigations of Ra+^+ properties to test possibilities of new optical frequency standards

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    The present work tests the suitability of the narrow transitions $7s \ ^2S_{1/2} \to 6d ^2D_{3/2}and and 7s ^2S_{1/2} \to 6d ^2D_{5/2}inRa in Ra^+foropticalfrequencystandardstudies.Ourcalculationsofthelifetimesofthemetastable for optical frequency standard studies. Our calculations of the lifetimes of the metastable 6dstatesusingtherelativisticcoupledclustertheorysuggestthattheyaresufficientlylongforRa states using the relativistic coupled-cluster theory suggest that they are sufficiently long for Ra^+$ to be considered as a potential candidate for an atomic clock. This is further corroborated by our studies of the hyperfine interactions, dipole and quadrupole polarizabilities and quadrupole moments of the appropriate states of this system.Comment: Latex files, 5 pages, 1 figur

    Communication

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    Visualizing the functional interactions of biomolecules such as proteins and nucleic acids is key to understanding cellular life on the molecular scale. Spatial proximity is often used as a proxy for the direct interaction of biomolecules. However, current techniques to visualize spatial proximity are either limited by spatial resolution, dynamic range, or lack of single-molecule sensitivity. Here, we introduce Proximity-PAINT (pPAINT), a variation of the super-resolution microscopy technique DNA-PAINT. pPAINT uses a split-docking-site configuration to detect spatial proximity with high sensitivity, low false-positive rates, and tunable detection distances. We benchmark and optimize pPAINT using designer DNA nanostructures and demonstrate its cellular applicability by visualizing the spatial proximity of alpha- and beta-tubulin in microtubules using super-resolution detection. © 2020 Wiley-VCH GmbH

    Single-molecule super-resolution imaging of chromosomes and in situ haplotype visualization using Oligopaint FISH probes

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    Fluorescence in situ hybridization (FISH) is a powerful single-cell technique for studying nuclear structure and organization. Here we report two advances in FISH-based imaging. We first describe the in situ visualization of single-copy regions of the genome using two single-molecule super-resolution methodologies. We then introduce a robust and reliable system that harnesses single-nucleotide polymorphisms (SNPs) to visually distinguish the maternal and paternal homologous chromosomes in mammalian and insect systems. Both of these new technologies are enabled by renewable, bioinformatically designed, oligonucleotide-based Oligopaint probes, which we augment with a strategy that uses secondary oligonucleotides (oligos) to produce and enhance fluorescent signals. These advances should substantially expand the capability to query parent-of-origin-specific chromosome positioning and gene expression on a cell-by-cell basis

    Calculation of energy levels and transition amplitudes for barium and radium

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    The radium atom is a promising system for studying parity and time invariance violating weak interactions. However, available experimental spectroscopic data for radium is insufficient for designing an optimal experimental setup. We calculate the energy levels and transition amplitudes for radium states of significant interest. Forty states corresponding to all possible configurations consisting of the 7s7s, 7p7p and 6d6d single-electron states as well as the states of the 7s8s7s8s, 7s8p7s8p and 7s7d7s7d configurations have been calculated. The energies of ten of these states corresponding to the 6d26d^2, 7s8s7s8s, 7p27p^2, and 6d7p6d7p configurations are not known from experiment. Calculations for barium are used to control the accuracy.Comment: 12 pages, 4 table

    On-line Excited-State Laser Spectroscopy of Trapped Short-Lived Ra+^+ Ions

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    As an important step towards an atomic parity violation experiment in one single trapped Ra+^+ ion, laser spectroscopy experiments were performed with on-line produced short-lived 212,213,214^{212,213,214}Ra+^+ ions. The isotope shift of the 6\,^2D3/2_{3/2}\,-\,7\,^2P1/2_{1/2} and 6\,^2D3/2_{3/2}\,-\,7\,^2P3/2_{3/2} transitions and the hyperfine structure constant of the 7\,^2S1/2_{1/2} and 6\,^2D3/2_{3/2} states in 213^{213}Ra+^+ were measured. These values provide a benchmark for the required atomic theory. A lower limit of 232(4)232(4) ms for the lifetime of the metastable 6\,^2D5/2_{5/2} state was measured by optical shelving.Comment: 4.2 pages, 6 figures, 2 tables

    How much do delayed health care seeking, delayed care provision and diversion from primary care contribute to the transmission of STIs

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    Objectives: To explore the changing pattern of condom use from 1990 to 2000; to identify sociodemographic and behavioural factors associated with condom use; and reasons for condom use in 2000. Methods: Large probability sample surveys administered among those resident in Britain aged 16–44 (n = 13 765 in 1990, n = 11 161 in 2000). Face to face interviews with self completion components collected sociodemographic, behavioural, and attitudinal data. Results: Condom use in the past year among sexually active 16–24 year old men increased from 61.0% in 1990 to 82.1% in 2000 (p<0.0001), and from 42.0% to 63.2% (p<0.0001) among women of the same age, with smaller increases among older age groups. Among individuals reporting at least two partners in the previous 4 week period, approximately two thirds reported inconsistent or no condom use (63.1% (95% CI 55.9% to 69.8%) of the men and 68.5% (95% CI 57.6% to 77.7%) of the women). Conclusions: Rates of condom use increased substantially between 1990 and 2000, particularly among young people. However, inconsistent condom use by individuals with high rates of partner acquisition may contribute significantly to the recent resurgence in STIs. This group is an important target for intensive and specific sexual health interventions

    Test of CPT and Lorentz invariance from muonium spectroscopy

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    Following a suggestion of Kostelecky et al. we have evaluated a test of CPT and Lorentz invariance from the microwave spectroscopy of muonium. Hamiltonian terms beyond the standard model violating CPT and Lorentz invariance would contribute frequency shifts δν12\delta\nu_{12} and δν34\delta\nu_{34} to ν12\nu_{12} and ν34\nu_{34}, the two transitions involving muon spin flip, which were precisely measured in ground state muonium in a strong magnetic field of 1.7 T. The shifts would be indicated by anti-correlated oscillations in ν12\nu_{12} and ν34\nu_{34} at the earth's sidereal frequency. No time dependence was found in ν12\nu_{12} or ν34\nu_{34} at the level of 20 Hz, limiting the size of some CPT and Lorentz violating parameters at the level of 2×10232\times10^{-23} GeV, representing Planck scale sensitivity and an order of magnitude improvement in sensitivity over previous limits for the muon.Comment: 4 pages, 4 figures, uses REVTeX and epsf, submitted to Phys. Rev. Let
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