Background Longitudinal left ventricular (LV) contraction can be impaired in the presence of a normal LV ejection fraction (LVEF), and abnormalities have been reported in global longitudinal strain ...(GLS), long-axis systolic excursion (SExc), and the peak systolic velocity (s`) of mitral annular motion using tissue Doppler imaging (TDI). However, the relationships of GLS with s` and SExc have not been systematically evaluated in subjects with a normal LVEF, and whether these relationships might be affected by variations in LV end-diastolic length (LVEDL) and heart rate is unknown. Methods We investigated the univariate and multivariate correlations of GLS with TDI measurements of s` and SExc (both using averages of the septal and lateral walls), LVEDL and heart rate in subjects with a normal LVEF (>50%) but a low peak early diastolic mitral annular velocity (septal e`≤ 7.0 cm/s and lateral e`≤ 9 cm/s), and thus an increased risk of a future cardiac event. Results 84 subjects (age 66±8 years, 29 males) with a LVEF of 62±6% and GLS of -17.5±2.3% were studied. On univariate analysis the absolute value of GLS was positively correlated with s`(r = 0.28, p<0.01) and SExc (r = 0.50, p<0.001) and inversely correlated with heart rate (r = -0.36, p = 0.001), but was not correlated with LVEDL (r = -0.15). In multivariate models, SExc explained more of the variance in GLS than s`, and absolute GLS was not only positively correlated with SExc, but also inversely correlated with LVEDL. Heart rate was an independent inverse correlate of GLS in conjunction with LVEDL and either s` or SExc, but made a larger contribution in models which included s`. Interobserver correlations were close for s` and SExc (r = 0.89–0.93), but only moderate for GLS (r = 0.71). Conclusion In subjects with a normal LVEF but reduced e`, the absolute value of GLS is more closely related to SExc than s`, and is also independently and inversely related to LVEDL and heart rate. Measurement of SExc may provide a useful additional or alternative technique to GLS for the assessment of LV long-axis function.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We present high-resolution H i data obtained using the Australia Telescope Compact Array to resolve the near/far distance ambiguities towards a sample of compact H ii regions from the Red MSX Source ...(RMS) survey. The high-resolution data are complemented with lower resolution archival H i data extracted from the Southern and Very Large Array (VLA) Galactic Plane surveys. We resolve the distance ambiguity for nearly all of the 105 sources where the continuum was strong enough to allow analysis of the H i absorption line structure. This represents another step in the determination of distances to the total RMS sample, which with over 1000 massive young stellar objects and compact H ii regions is the largest and most complete sample of its kind. The full sample will allow the distribution of massive star formation in the Galaxy to be examined.
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BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Objectives: To examine the relation of arterial compliance to diastolic dysfunction in hypertensive patients with suspected diastolic heart failure (HF). Patients: 70 medically treated hypertensive ...patients with exertional dyspnoea (40 women, mean (SD) age 58 (8) years) and 15 normotensive controls. Main outcome measures: Mitral annular early diastolic velocity with tissue Doppler imaging and flow propagation velocity were used as linear measures of diastolic function. Arterial compliance was determined by the pulse pressure method. Results: According to conventional Doppler echocardiography of transmitral and pulmonary venous flow, diastolic function was classified as normal in 33 patients and abnormal in 37 patients. Of those with diastolic dysfunction, 28 had mild (impaired relaxation) and nine had advanced (pseudonormal filling) dysfunction. Arterial compliance was highest in controls (mean (SD) 1.32 (0.58) ml/mm Hg) and became progressively lower in patients with hypertension and normal function (1.04 (0.37) ml/mm Hg), impaired relaxation (0.89 (0.42) ml/mm Hg), and pseudonormal filling (0.80 (0.45) ml/mm Hg, p = 0.011). In patients with diastolic dysfunction, arterial compliance was inversely related to age (p = 0.02), blood pressure (p < 0.001), and estimated filling pressures (p < 0.01) and directly related to diastolic function (p < 0.01). After adjustment for age, sex, body size, blood pressure, and ventricular hypertrophy, arterial compliance was independently predictive of diastolic dysfunction. Conclusions: In hypertensive patients with exertional dyspnoea, progressively abnormal diastolic function is associated with reduced arterial compliance. Arterial compliance is an independent predictor of diastolic dysfunction in patients with hypertensive heart disease and should be considered a potential target for intervention in diastolic HF.
Crystal chemical design principles were applied to synthesise novel U
dominant and titanium excess betafite phases Ca
U
Zr
Ti
O
and Ca
U
Zr
Ti
O
, in high yield (85-95 wt%), and ceramic density ...reaching 99% of theoretical. Substitution of Ti on the A-site of the pyrochlore structure, in excess of full B-site occupancy, enabled the radius ratio (r
/r
= 1.69) to be tuned into the pyrochlore stability field, approximately 1.48 ≲ r
/r
≲ 1.78, in contrast to the archetype composition CaUTi
O
(r
/r
= 1.75). U L
-edge XANES and U 4f
and U 4f
XPS data evidenced U
as the dominant speciation, consistent with the determined chemical compositions. The new betafite phases, and further analysis reported herein, point to a wider family of actinide betafite pyrochlores that could be stabilised by application of the underlying crystal chemical principle applied here.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
To ensure efficient genome duplication, cells have evolved numerous factors that promote unperturbed DNA replication and protect, repair and restart damaged forks. Here we identify downstream ...neighbor of SON (DONSON) as a novel fork protection factor and report biallelic DONSON mutations in 29 individuals with microcephalic dwarfism. We demonstrate that DONSON is a replisome component that stabilizes forks during genome replication. Loss of DONSON leads to severe replication-associated DNA damage arising from nucleolytic cleavage of stalled replication forks. Furthermore, ATM- and Rad3-related (ATR)-dependent signaling in response to replication stress is impaired in DONSON-deficient cells, resulting in decreased checkpoint activity and the potentiation of chromosomal instability. Hypomorphic mutations in DONSON substantially reduce DONSON protein levels and impair fork stability in cells from patients, consistent with defective DNA replication underlying the disease phenotype. In summary, we have identified mutations in DONSON as a common cause of microcephalic dwarfism and established DONSON as a critical replication fork protein required for mammalian DNA replication and genome stability.
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IJS, NUK, SBMB, UL, UM, UPUK
The metamorphic core of the Himalaya is composed of Indian cratonic rocks with two distinct crustal affinities that are defined by radiogenic isotopic geochemistry and detrital zircon age spectra. ...One is derived predominantly from the Paleoproterozoic and Archean rocks of the Indian cratonic interior and is either represented as metamorphosed sedimentary rocks of the Lesser Himalayan Sequence (LHS) or as slices of the distal cratonic margin. The other is the Greater Himalayan Sequence (GHS) whose provenance is less clear and has an enigmatic affinity. Here we present new detrital zircon Hf analyses from LHS and GHS samples spanning over 1000 km along the orogen that respectively show a striking similarity in age spectra and Hf isotope ratios. Within the GHS, the zircon age populations at 2800–2500 Ma, 1800 Ma, 1000 Ma and 500 Ma can be ascribed to various Gondwanan source regions; however, a pervasive and dominant Tonianage population (∼860–800 Ma) with a variably enriched radiogenic Hf isotope signature (εHf = 10 to −20) has not been identified from Gondwana or peripheral accreted terranes. We suggest this detrital zircon age population was derived from a crustal province that was subsequently removed by tectonic erosion. Substantial geologic evidence exists from previous studies across the Himalaya supporting the Cambro-Ordovician Kurgiakh Orogeny. We propose the tectonic removal of Tonian lithosphere occurred prior to or during this Cambro-Ordovician episode of orogenesis in a similar scenario as is seen in the modern Andean and Indonesian orogenies, wherein tectonic processes have removed significant portions of the continental lithosphere in a relatively short amount of time. This model described herein of the pre-Himalayan northern margin of Greater India highlights the paucity of the geologic record associated with the growth of continental crust. Although the continental crust is the archive of Earth history, it is vital to recognize the ways in which preservation bias and destruction of continental crust informs geologic models.
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•Zircon from the metamorphic core of the Himalaya have unique provenance.•The zircon populations from the Greater Himalayan Sequence are unique in Gondwana.•Tectonic erosion can explain this missing tectonic province.•Recognizing the preservation bias is needed to inform geologic models.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Portland cement-based grouts used for radioactive waste immobilisation contain a Ca- and Si-rich binder phase, known as calcium-silicate-hydrate (C-S-H). Depending on the blend of cement used, the ...Ca/Si ratio can vary considerably. A range of C-S-H minerals with Ca/Si ratios from 0.6 to 1.6 were synthesised and contacted with aqueous U(VI) at 0.5 mM and 10 mM concentrations. Solid-state
Si MAS-NMR spectroscopy was applied to probe the Si coordination environment in U(VI)-contacted C-S-H minerals and, in conjunction with U L
-edge X-ray absorption spectroscopy analysis, inferences of the fate of U(VI) in these systems were made. At moderate or high Ca/Si ratios, uranophane-type uranyl silicates or Ca-uranates dominated, while at the lowest Ca/Si ratios, the formation of a Ca-bearing uranyl silicate mineral, similar to haiweeite (Ca(UO
)
Si
O
(OH)
·3H
O) or Ca-bearing weeksite (Ca
(UO
)
Si
O
·10H
O) was identified. This study highlights the influence of Ca/Si ratio on uranyl sequestration, of interest in the development of post-closure safety models for U-bearing radioactive waste disposal.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The transmitral E wave and the peak velocity of early diastolic mitral annular motion (e`) both decrease with age, but the mechanisms underlying these age-related changes are incompletely understood. ...This study investigated the possible contributions of blood pressure (BP) and left ventricular end-diastolic length (LVEDL) to age-related reductions in E and e`.
The study group were 82 healthy adult subjects <55 years of age who were not obese or hypertensive. Transmitral flow and mitral annular motion were recorded using pulsed-wave Doppler. LVEDL was measured from the mitral annular plane to the apical endocardium.
Age was positively correlated with diastolic BP and septal wall thickness (SWT), inversely correlated with LVEDL (β = -0.25) after adjustment for sex and body surface area, but was not related to left ventricular end-diastolic diameter (LVEDD). Age was also inversely correlated with E (r = -0.36), septal e`(r = -0.53) and lateral e`(r = -0.53). On multivariable analysis, E was inversely correlated with diastolic BP and LVEDD, septal e`was inversely correlated with diastolic BP and positively correlated with SWT and LVEDL, after adjusting for body mass index, whilst lateral e`was inversely correlated with diastolic BP and positively correlated with LVEDL.
The above findings are consistent with higher BP being a contributor to age-related reductions in both E and e`and shortening of LVEDL with age being a contributor to the age-related reduction in e`. An implication of these findings is that slowing of myocyte relaxation is unlikely to be the sole, and may not be the main, mechanism underlying age-related decreases in E and e`.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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