This paper presents work using the capabilities of two TEM with in-situ ion irradiation facilities: Microscope and Ion Accelerator for Materials Investigation (MIAMI) at the University of ...Huddersfield and Joint Accelerators for Nano-science and Nuclear Simulation JANNuS at Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Orsay, France, to study the nucleation and growth of He bubbles in silicon carbide (SiC) and to carry out an investigation into bubble behaviour at high temperatures and under displacing irradiation. Preliminary results on bubble nucleation and growth during He irradiation of SiC are presented together with results from a simultaneous anneal and high-energy heavy-ion irradiation of samples containing He bubbles. The displacing irradiation is observed to impede He bubble growth resulting in smaller bubbles than those obtained from an anneal alone. A tentative interpretation of these observations is presented.
Using the new MIAMI facility (Microscope and Ion Accelerators for Materials Investigations) at the University of Huddersfield, an in-situ TEM study has been carried out on the effects of helium ...implantation on a tri-layer system consisting of monocrystalline silicon (c-Si), silicon dioxide (SiO2) and polycrystalline silicon (poly-Si). Co-irradiation of these three components enabled direct comparisons to be made of differences between the response of c-Si and poly-Si to the He irradiation; in particular, differences in the development of interstitial clusters and bubbles and eventual amorphisation. For implantations to high fluences (>1017 ions/cm2), very significant levels of porosity were observed to build up in the Si, leading to changes in the width of the Si layers of up to 29% Although no helium bubbles were formed in the SiO2 layer, a very significant dimensional change (but in this case an observed shrinkage) also occurred in this material. Finally, room temperature amorphisation of the Si was observed at high fluences, beginning at somewhat lower fluences in the poly-Si than in the c-Si. A brief discussion of the origins of these effects is presented.
Background Maternal chronic hypertension is associated with adverse pregnancy outcomes. Previous studies examined the association between either chronic hypertension or antihypertensive treatment and ...adverse pregnancy outcomes. We aimed to synthesize the evidence on the effect of chronic hypertension/antihypertensive treatment on adverse pregnancy outcomes. Methods and Results Medline/PubMed, EMBASE, and Web of Science were searched; we included observational studies and assessed the effect of race/ethnicity, where possible, following a registered protocol (CRD42019120088). Random-effects meta-analyses were used. A total of 81 studies were identified on chronic hypertension, and a total of 16 studies were identified on antihypertensive treatment. Chronic hypertension was associated with higher odds of preeclampsia (adjusted odd ratio aOR, 5.43; 95% CI, 3.85-7.65); cesarean section (aOR, 1.87; 95% CI, 1.6-2.16); maternal mortality (aOR, 4.80; 95% CI, 3.04-7.58); preterm birth (aOR, 2.23; 95% CI, 1.96-2.53); stillbirth (aOR, 2.32; 95% CI, 2.22-2.42); and small for gestational age (SGA) (aOR, 1.96; 95% CI, 1.6-2.40). Subgroup analyses indicated that maternal race/ethnicity does not influence the observed associations. Women with chronic hypertension on antihypertensive treatment (versus untreated) had higher odds of SGA (aOR, 1.86; 95% CI, 1.38-2.50). Conclusions Chronic hypertension is associated with adverse pregnancy outcomes, and these associations appear to be independent of maternal race/ethnicity. In women with chronic hypertension, those on treatment had a higher risk of SGA, although the number of studies was limited. This could result from a direct effect of the treatment or because severe hypertension during pregnancy is a risk factor for SGA and women with severe hypertension are more likely to be treated. The effect of antihypertensive treatment on SGA needs to be further tested with large randomized controlled trials.
Results are reported from an amplitude analysis of the B+ → D+D− K+ decay. The analysis is carried out using LHCb proton-proton collision data taken at √s = 7, 8, and 13 TeV, corresponding to a total ...integrated luminosity of 9 fb−1. In order to obtain a good description of the data, it is found to be necessary to include new spin-0 and spin-1 resonances in the D−K+ channel with masses around 2.9 GeV/c2, and a new spin-0 charmonium resonance in proximity to the spin-2 χc2(3930) state.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Reconstructing ancient tectonic environments is inherently difficult and requires the integration of many datasets. Here we attempt to reconstruct the tectonic setting of a Proterozoic magmatic rock ...suite from the Archean to Mesoproterozoic Gawler Craton, South Australia. We evaluate previous models of subduction or non-subduction tectonics for the St Peter Suite through field observations coupled with geochemical and isotopic data. Field observations indicate the presence of mafic magma chambers, felsic plutons and zones of mixing represented by multiphase plutons and zones of magma transfer. Syn-magmatic and solid-state deformation fabrics suggest magmatism was associated with a compressional tectonic regime, at least during some stages of magmatism. Zircon U-Pb geochronology suggests magmatism occurred between ca 1633 and ca 1608 Ma, an interval of ca 25 Myr. Mafic rocks are tholeiitic and enrichment in high field strength and light rare earth elements supports a modified mantle source region. Mafic rocks have εNd
1620 Ma
values around 0, and zircon εHf
(t)
values around 4, supporting minor crustal contamination. Felsic plutons have a geochemical signature similar to average continental crust, εNd
1620 Ma
between -3.7 and 0.4, and zircon Lu-Hf isotopic compositions that yield to εHf
(t)
values between -1.8 and 7.7, suggesting they were derived from fractionation of enriched tholeiitic parent magmas. A model for the formation of the St Peter Suite that is most consistent with the available data is one that places the magmatism in a broadly continental magmatic arc setting, albeit one in which little or no Archean crust was involved. Potentially this magmatic arc could have been built on a thinned, or hyper-extended continental margin. The integration of structural, geochemical and isotopic constraints has provided a more holistic view of the St Peter Suite petrogenesis than previously available.
Highlights
Evaluation of models of subduction vs non-subduction tectonics for formation of Paleoproterozoic magmatic suite
Evidence for syn-magmatic compression and mafic-felsic magma mingling
Isotopically juvenile (Nd--Sr--Hf) with mantle-like zircon δ
18
O values
Continental arc setting proposed, possibly on hyper-extended continental margin
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
Liver fibrosis results from the excessive secretion of matrix proteins by hepatic stellate cells (HSC), which proliferate during fibrotic liver injury. We have studied a model of spontaneous recovery ...from liver fibrosis to determine the biological mechanisms mediating resolution. Livers were harvested from rats at 0, 3, 7, and 28 d of spontaneous recovery from liver fibrosis induced by 4 wk of twice weekly intraperitoneal injections with CCl4. Hydroxyproline analysis and histology of liver sections indicated that the advanced septal fibrosis observed at time 0 (peak fibrosis) was remodeled over 28 d of recovery to levels close to control (untreated liver). alpha-Smooth muscle actin staining of liver sections demonstrated a 12-fold reduction in the number of activated HSC over the same time period with evidence of HSC apoptosis. Ribonuclease protection analysis of liver RNA extracted at each recovery time point demonstrated a rapid decrease in expression of the collagenase inhibitors TIMP-1 and TIMP-2, whereas collagenase mRNA expression remained at levels comparable to peak fibrosis. Collagenase activity in liver homogenates increased through recovery. We suggest that apoptosis of activated HSC may vitally contribute to resolution of fibrosis by acting as a mechanism for removing the cell population responsible for both producing fibrotic neomatrix and protecting this matrix from degradation via their production of TIMPs.
It's all in the ligand: By choice of the appropriate diphosphine ligand a previously linear‐selective alkyne hydroacylation process can be “switched” to be highly branched‐selective (see scheme, ...l=linear, b=branched). Structural data for the ortho‐iPr‐dppe–rhodium catalyst suggest restricted rotation of the phosphine aryl units may be responsible for the observed selectivity.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Conventional flood control has emphasized structural measures such as levees, reservoirs, and engineered channels—measures that typically simplify river channels and cut them off from their ...floodplain, both with adverse environmental consequences. Structural measures tend to be rigid and not easily adapted to increased flooding regimes resulting from environmental change. Such actions also limit the natural hydrologic benefits of floodplains such as storing floodwaters, improving water quality, providing habitat for invertebrates and fish during periods of inundation, and supporting a multitude of cultural services. As these benefits are more widely recognized, policies are being adopted to encourage projects that reduce flood risks and restore floodplain ecosystems, while acknowledging the social-ecological context. The number of such projects, however, remains small. We assessed four multi-benefit floodplain projects (two in California, United States, and two in Germany) and characterized their drivers, history, and measures implemented. In both United States cases, the dominant driver behind the project was flood risk reduction, and ecosystem restoration followed, in one case inadvertently, in the other as a requirement to receive a subsidy for a flood risk reduction project. One German case was motivated by ecosystem restoration, but it was more widely accepted because it also offered flood management benefits. The fourth case was conceived in terms of balanced goals of flood risk reduction, ecosystem restoration, and recreation. We conclude that projects that both reduce flood risk and restore ecosystems are clearly possible and often cost-effective, and that they could be more widely implemented. The principal barriers are often institutional and regulatory, rather than technical.
Long-interval intracortical inhibition (LICI), measured with paired-pulse transcranial magnetic stimulation, is a candidate biomarker for monitoring disease activity in epilepsy. However, in a large ...retrospective cohort study, Bauer et al. observe no differences in LICI between patients with refractory epilepsy and healthy controls, suggesting its lack of suitability as a biomarker.
Abstract
Cortical excitability, as measured by transcranial magnetic stimulation combined with electromyography, is a potential biomarker for the diagnosis and follow-up of epilepsy. We report on long-interval intracortical inhibition data measured in four different centres in healthy controls (n = 95), subjects with refractory genetic generalized epilepsy (n = 40) and with refractory focal epilepsy (n = 69). Long-interval intracortical inhibition was measured by applying two supra-threshold stimuli with an interstimulus interval of 50, 100, 150, 200 and 250 ms and calculating the ratio between the response to the second (test stimulus) and to the first (conditioning stimulus). In all subjects, the median response ratio showed inhibition at all interstimulus intervals. Using a mixed linear-effects model, we compared the long-interval intracortical inhibition response ratios between the different subject types. We conducted two analyses; one including data from the four centres and one excluding data from Centre 2, as the methods in this centre differed from the others. In the first analysis, we found no differences in long-interval intracortical inhibition between the different subject types. In all subjects, the response ratios at interstimulus intervals 100 and 150 ms showed significantly more inhibition than the response ratios at 50, 200 and 250 ms. Our second analysis showed a significant interaction between interstimulus interval and subject type (P = 0.0003). Post hoc testing showed significant differences between controls and refractory focal epilepsy at interstimulus intervals of 100 ms (P = 0.02) and 200 ms (P = 0.04). There were no significant differences between controls and refractory generalized epilepsy groups or between the refractory generalized and focal epilepsy groups. Our results do not support the body of previous work that suggests that long-interval intracortical inhibition is significantly reduced in refractory focal and genetic generalized epilepsy. Results from the second analysis are even in sharper contrast with previous work, showing inhibition in refractory focal epilepsy at 200 ms instead of facilitation previously reported. Methodological differences, especially shorter intervals between the pulse pairs, may have contributed to our inability to reproduce previous findings. Based on our results, we suggest that long-interval intracortical inhibition as measured by transcranial magnetic stimulation and electromyography is unlikely to have clinical use as a biomarker of epilepsy.
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