52 research outputs found

    Reinforcement interfaces in low-carbon concretes

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    Calcium sulfoaluminate cement (CSA) is a potential low-carbon binder that has a markedly less alkaline matrix environment compared to traditional Portland cement. Investigations on its long-term chemical compatibility with different reinforcements (i.e. glass fibre and steel rebar) are necessary before widespread adoption could occur. In this project, studies mainly focus on the microstructural evolution at interfacial zones over time, which has a significant impact on the durability properties of reinforced concretes. Glass fibre reinforced composites made with two matrix formulations (OPC, and OPC plus calcium sulfoaluminate based matrices) aged for 10 years at 25℃ and steel reinforced CSA concretes aged for 28 days and 1.5 years are studied. Optical transmitted microscopy and SEM/EDX on the thin section petrographic specimens of composites are employed to give a straightforward interfacial zone characterization. The results suggest that CSA cement is highly compatible with the embedded glass fibre and steel reinforcement in the long term. Aged GRC composite modified by calcium sulfoaluminate cement shows greatly retained toughness, accompanied by considerably flexible interfacial and interfilamentary areas around the glass fibres. This is in contrary to the aged OPC/GRC, which demonstrates significantly brittle behaviour with substantial densification of C-S-H/CH intermixture occurring around glass fibres. In the steel reinforced CSA concrete, elemental mappings clearly show that there is a non-continuous aluminium-rich layer at the steel/concrete interface; and the aluminium gel is slightly consumed over time by chemical reactions

    The production of OH in a nanosecond pulsed helium plasma jet impinging on water, saline, or pigskin

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    Applications of plasma-induced biological effects via reactive oxygen and nitrogen species (RONS) make the non-thermal atmospheric-pressure plasma jets an appealing tool in biomedical fields. The presence of biological materials, especially as part of the electrode circuit, may change the plasma properties and impact on the production of RONS at the plasma-biomaterial interface. Effects of biomaterials on the production of hydroxyl radicals (OH) in a nanosecond pulsed, atmospheric-pressure plasma jet were investigated using a needle-to-plate electrode configuration with water, phosphate-buffered saline (PBS), or pigskin covering the ground plate. Driven by 200 ns, 7 kV pulses at 1 kHz, a helium plasma jet was generated between the hollow needle electrode and the biomaterial. Temporally resolved UV-visible imaging showed that the use of pigskin slowed down the streamer head propagation, whereas a more pronounced surface ionization wave was developed on the surface when water was used. The highest OH(A-X) emission above the biomaterial surface was observed using the PBS-covered electrode plate comparing to water or pigskin. Spatiotemporally resolved laser-induced fluorescence (LIF) showed that more OH was produced in the region near the needle electrode for both water and PBS, and the use of pigskin resulted in least OH production overall. In addition, measurements of H2O2 production in the liquid were used to determine the OH concentration in the vicinity of the biomaterial and agreed well with the relative OH-LIF measurements obtained at the gas-liquid interface for water and PBS

    The honeysuckle genome provides insight into the molecular mechanism of carotenoid metabolism underlying dynamic flower coloration

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    Lonicera japonica is a wide-spread member of the Caprifoliaceae (honeysuckle) family utilized in traditional medical practices. This twining vine honeysuckle is also a much-sought ornamental, in part due to its dynamic flower coloration, which changes from white to gold during development. The molecular mechanism underlying dynamic flower coloration in L. japonica was elucidated by integrating whole genome sequencing, transcriptomic analysis, and biochemical assays. Here, we report a chromosome-level genome assembly of L. japonica, comprising nine pseudo-chromosomes with a total size of 843.2 Mb. We also provide evidence for a whole genome duplication event in the lineage leading to L. japonica, which occurred after its divergence from Dipsacales and Asterales. Moreover, gene expression analysis not only revealed correlated expression of the relevant biosynthetic genes with carotenoid accumulation, but also suggested a role for carotenoid degradation in L. japonica's dynamic flower coloration. The variation of flower color is consistent with not only the observed carotenoid accumulation pattern, but also with the release of volatile apocarotenoids that presumably serve as pollinator attractants. Beyond novel insights into the evolution and dynamics of flower coloration, the high-quality L. japonica genome sequence also provides a foundation for molecular breeding to improve desired characteristics

    Endovascular Recanalization of Non-acute Symptomatic Middle Cerebral Artery Total Occlusion and Its Short-Term Outcomes

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    Background and Purpose: The optimal treatment for patients with non-acute symptomatic middle cerebral artery (MCA) total occlusion and a high risk of recurrent ischemic stroke despite medical management is not well-established. We aimed to assess the feasibility, safety, and short-term outcomes of angioplasty and stenting for these patients.Methods: Data of 22 patients with non-acute symptomatic MCA total occlusion who have failed medical management and undergone endovascular recanalization were retrospectively collected in our prospective database. All occlusive lesions were predilated with conventional balloons, followed by paclitaxel-coated coronary balloon inflation or not, and then a remedial stenting was performed or not, depending on the discretion of the operator. The rate of successful recanalization, perioperative outcomes, and short-term outcomes, such as restenosis and stroke recurrence, was analyzed.Results: Successful recanalization was achieved in 95.5% of patients, with 14 patients undergoing balloon angioplasty and 7 patients undergoing remedial stenting. Seven patients developed perioperative complications, including one patient with persistent neurological deficit. Over a median clinical follow-up duration of 5.0 months, only one patient had recurrent ischemic symptoms attributed to the cessation of antiplatelet treatment owing to postoperative intracranial hemorrhage. The proportion of patients who achieved favorable clinical outcome (modified ranking scale score of 0–2) was 85.7%. Post-procedural repeat vascular imaging was performed at 4.5 ± 1.84 months, with nine and one patient undergoing cerebral angiography and magnetic resonance angiography, respectively. One (10%) artery presented with asymptomatic reocclusion.Conclusions: Angioplasty and stenting may be feasible for the patients with non-acute symptomatic atherosclerotic MCA total occlusive disease who have failed medical management

    Safety and efficacy of endovascular recanalization for symptomatic non-acute atherosclerotic intracranial large artery occlusion

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    Background and objectiveThe optimal treatment for patients with symptomatic non-acute atherosclerotic intracranial large artery occlusion (ILAO) despite medical treatment is not well established. We aimed to assess the safety, efficacy, and feasibility of angioplasty and stenting for these patients.MethodsA total of 251 consecutive patients with symptomatic non-acute atherosclerotic ILAO treated with interventional recanalization were retrospectively collected in our center from March 2015 to August 2021. The rate of successful recanalization, perioperative complications, and follow-up outcomes were evaluated.ResultsSuccessful recanalization was achieved in 88.4% (222/251) of the patients. A total of 24 (24/251, 9.6%) symptomatic complications occurred among 251 procedures. In the 193 patients with clinical follow-up during 19.0 ± 14.7 months, 11 (11/193, 5.7%) patients developed ischemic stroke and four (4/193, 2.1%) patients developed transient ischemic attack (TIA). In the 106 patients with vascular imaging follow-up during 6.8 ± 6.6 months, seven (7/106, 6.6%) patients had restenosis and 10 (10/106, 9.4%) patients had reocclusion.ConclusionThis study suggests that interventional recanalization may be a feasible, basically safe, and an effective alternative in carefully selected patients with symptomatic non-acute atherosclerotic ILAO who have failed medical management

    The honeysuckle genome provides insight into the molecular mechanism of carotenoid metabolism underlying dynamic flower coloration

    Get PDF
    Lonicera japonica is a wide-spread member of the Caprifoliaceae (honeysuckle) family utilized in traditional medical practices. This twining vine honeysuckle is also a much-sought ornamental, in part due to its dynamic flower coloration, which changes from white to gold during development. The molecular mechanism underlying dynamic flower coloration in L. japonica was elucidated by integrating whole genome sequencing, transcriptomic analysis, and biochemical assays. Here, we report a chromosome-level genome assembly of L. japonica, comprising nine pseudochromosomes with a total size of 843.2 Mb. We also provide evidence for a whole genome duplication event in the lineage leading to L. japonica, which occurred after its divergence from Dipsacales and Asterales. Moreover, gene expression analysis not only revealed correlated expression of the relevant biosynthetic genes with carotenoid accumulation, but also suggested a role for carotenoid degradation in L. japonica’s dynamic flower coloration. The variation of flower color is consistent with not only the observed carotenoid accumulation pattern, but also with the release of volatile apocarotenoids that presumably serve as pollinator attractants. Beyond novel insights into the evolution and dynamics of flower coloration, the high-quality L. japonica genome sequence also provides a foundation for molecular breeding to improve desired characteristics
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