55 research outputs found

    4,4′-Bipyridinium bis­(oxalato-κ2 O 1,O 2)cuprate(II): an ion-pair complex

    Get PDF
    The title compound, (C10H10N2)[Cu(C2O4)2] or (4,4′-H2bpy)[Cu(ox)2] (bpy is 4,4′-bipyridine and ox is oxalate), is an ion-pair complex comprising a protonated 4,4′-bipyridinium dication and a square-planar dioxalatocopper(II) dianion. In the centrosymmetric dianion, the CuII centre is coordinated by four O atoms from the two dicrete oxalate ligands [Cu—O = 1.9245 (19) and 1.9252 (17) Å], while the planar dications are also centrosymmetric. Inter-species N—H⋯O hydrogen bonds link the cations and anions into one-dimensional chains and, together with weak intra-ion C—H⋯O inter­actions, give a two-dimensional sheet structure

    Bis(2-amino-4-methyl-1,3-thia­zole-κN 3)dichloridocadmium(II)

    Get PDF
    In the title compound, [CdCl2(C4H6N2S)2], the CdII atom is coordinated by two chlorido ligands and two N atoms of the 2-amino-5-methyl-1,3-thia­zole (amtz) ligands in a slightly distorted tetra­hedral coordination geometry. Intra- and inter­molecular N—H⋯Cl hydrogen bonding stabilizes the crystal structure. A weak S⋯Cl inter­action [3.533 (2) Å] is observed between neighboring mol­ecules

    Bis(2-amino­thia­zole-4-acetato)aquazinc(II)

    Get PDF
    In the title compound, [Zn(C5H5N2O2S)2(H2O)], the central Zn atom (2 site symmetry) is five-coordinated by two N and three O atoms [Zn—N = 2.047 (3) Å, Zn—O = 2.099 (2) and 1.974 (4) Å] in a distorted square-pyramidal geometry. Besides one O atom from a water mol­ecule, two 2-amino­thia­zole-4-acetate ligands provide two N and two O atoms as coordinated atoms. In the crystal structure, inter­molecular O—H⋯O and N—H⋯O hydrogen bonds connect the mol­ecules into an infinite three-dimensional framework

    Bis(ethyl 2-amino-4-thia­zoleacetato-κN)silver(I) nitrate

    Get PDF
    In the title complex, [Ag(C7H10N2O2S)2]NO3, the AgI cation is bicoordinated in an almost linear configuration by two N-donor atoms of the thia­zole rings of two distinct ethyl 2-amino-4-thia­zoleacetate (EATA) ligands. The dihedral angle between the two thia­zole rings is 49.9°. A weak Ag⋯O (2.729 Å) inter­action between the Ag cation and one of the O atoms from the nitrate anion is observed, and a pseudo-dimer is formed through a weak Ag⋯S (3.490 Å) inter­action between the Ag cation and the S atom of the thia­zole ring of a symmetry-related mol­ecule. In the crystal structure, there are intra- and inter­molecular N—H⋯O hydrogen bonds. The occurrence of inter­molecular N—H⋯O hydrogen bonds results in the formation of two-dimensional sheets parallel to (010), which are further linked into a three-dimensional network through weak C—H⋯O inter­actions

    Observation and quantification of pseudogap in unitary Fermi gases

    Full text link
    The nature of pseudogap lies at the heart of strongly-interacting superconductivity and superfluidity. With known pairing interactions, unitary Fermi gases provide an ideal testbed to verify whether a pseudogap can arise from many-body pairing. Here we report the observation of the long-sought pair-fluctuation-driven pseudogap in homogeneous unitary Fermi gases of lithium-6 atoms, by precisely measuring the spectral function through momentum-resolved microwave spectroscopy without the serious effects of final-state effect. We find a large pseudogap above the superfluid transition. The inverse pair lifetime exhibits a thermally-activated exponential behavior, uncovering the microscopic virtual pair breaking and recombination mechanism. The obtained large, T-independent single-particle scattering rate is comparable with that set by the Planckian limit. Our findings quantitatively characterize the pseudogap in strongly-interacting Fermi gases, highlighting the role of preformed pairing as a precursor to superfluidity

    Effect of dispersion on indistinguishability between single-photon wave-packets

    Full text link
    With propagating through a dispersive medium, the temporal-spectral profile of laser pulses should be inevitably modified. Although such dispersion effect has been well studied in classical optics, its effect on a single-photon wave-packet, i.e., the matter wave of a single-photon, has not yet been entirely revealed. In this paper, we investigate the effect of dispersion on indistinguishability of single-photon wave-packets through the Hong-Ou-Mandel (HOM) interference. By dispersively manipulating two indistinguishable single-photon wave-packets before interfering with each other, we observe that the difference of the second-order dispersion between two optical paths of the HOM interferometer can be mapped to the interference curve, indicating that (1) with the same amount of dispersion effect in both paths, the HOM interference curve must be only determined by the intrinsic indistinguishability between the wave-packets, i.e., dispersion cancellation due to the indistinguishability between Feynman paths; (2) unbalanced dispersion effect in two paths cannot be cancelled and will broaden the interference curve thus providing a way to measure the second-order dispersion coefficient. Our results suggest a more comprehensive understanding of the single-photon wave-packet and pave ways to explore further applications of the HOM interference

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

    Get PDF
    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
    corecore